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Sample records for facilitates beta-sheet recognition

  1. A novel mode of DNA recognition by a beta-sheet revealed by the solution structure of the GCC-box binding domain in complex with DNA.

    PubMed Central

    Allen, M D; Yamasaki, K; Ohme-Takagi, M; Tateno, M; Suzuki, M

    1998-01-01

    The 3D solution structure of the GCC-box binding domain of a protein from Arabidopsis thaliana in complex with its target DNA fragment has been determined by heteronuclear multidimensional NMR in combination with simulated annealing and restrained molecular dynamic calculation. The domain consists of a three-stranded anti-parallel beta-sheet and an alpha-helix packed approximately parallel to the beta-sheet. Arginine and tryptophan residues in the beta-sheet are identified to contact eight of the nine consecutive base pairs in the major groove, and at the same time bind to the sugar phosphate backbones. The target DNA bends slightly at the central CG step, thereby allowing the DNA to follow the curvature of the beta-sheet. PMID:9736626

  2. Sign Facilitation in Word Recognition.

    ERIC Educational Resources Information Center

    Wauters, Loes N.; Knoors, Harry E. T.; Vervloed, Mathijs P. J.; Aarnoutse, Cor A. J.

    2001-01-01

    This study examined whether use of sign language would facilitate reading word recognition by 16 deaf children (6- to 1 years-old) in the Netherlands. Results indicated that if words were learned through speech, accompanied by the relevant sign, accuracy of word recognition was greater than if words were learned solely through speech. (Contains…

  3. Training facilitates object recognition in cubist paintings.

    PubMed

    Wiesmann, Martin; Ishai, Alumit

    2010-01-01

    To the naïve observer, cubist paintings contain geometrical forms in which familiar objects are hardly recognizable, even in the presence of a meaningful title. We used fMRI to test whether a short training session about Cubism would facilitate object recognition in paintings by Picasso, Braque and Gris. Subjects, who had no formal art education, were presented with titled or untitled cubist paintings and scrambled images, and performed object recognition tasks. Relative to the control group, trained subjects recognized more objects in the paintings, their response latencies were significantly shorter, and they showed enhanced activation in the parahippocampal cortex, with a parametric increase in the amplitude of the fMRI signal as a function of the number of recognized objects. Moreover, trained subjects were slower to report not recognizing any familiar objects in the paintings and these longer response latencies were correlated with activation in a fronto-parietal network. These findings suggest that trained subjects adopted a visual search strategy and used contextual associations to perform the tasks. Our study supports the proactive brain framework, according to which the brain uses associations to generate predictions. PMID:20224810

  4. L2 Gender Facilitation and Inhibition in Spoken Word Recognition

    ERIC Educational Resources Information Center

    Behney, Jennifer N.

    2011-01-01

    This dissertation investigates the role of grammatical gender facilitation and inhibition in second language (L2) learners' spoken word recognition. Native speakers of languages that have grammatical gender are sensitive to gender marking when hearing and recognizing a word. Gender facilitation refers to when a given noun that is preceded by an…

  5. Study on the binding of Thioflavin T to beta-sheet-rich and non-beta-sheet cavities.

    PubMed

    Groenning, Minna; Olsen, Lars; van de Weert, Marco; Flink, James M; Frokjaer, Sven; Jørgensen, Flemming S

    2007-06-01

    Amyloid fibril formation plays a role in more than 20 diseases including Alzheimer's disease. In vitro detection of these fibrils is often performed using Thioflavin T (ThT), though the ThT binding mode is largely unknown. In the present study, spectral properties of ThT in binding environments representing beta-sheet-rich and non-beta-sheet cavities were examined. Acetylcholinesterase and gamma-cyclodextrin induced a characteristic ThT fluorescence similar to that with amyloid fibrils, whereas beta-cyclodextrin and the beta-sheet-rich transthyretin did not. The cavities of acetylcholinesterase and gamma-cyclodextrin were of similar diameter and only these cavities could accommodate two ThT ions according to molecular modelling. Binding stoichiometry studies also showed a possible binding of two ThT ions. Thus, the characteristic ThT fluorescence is induced in cavities with a diameter of 8-9A and a length able to accommodate the entire length of the ThT ion. The importance of a cavity diameter capable of binding two ThT ions, among others, indicates that an excimer formation is a plausible mechanism for the characteristic fluorescence. We propose a similar ThT binding mode in amyloid fibrils, where cavities of an appropriate size running parallel to the fibril axis have previously been proposed in several amyloid fibril models. PMID:17289401

  6. Interaction of self-assembling beta-sheet peptides with phospholipid monolayers: the role of aggregation state, polarity, charge and applied field.

    PubMed

    Protopapa, Elisabeth; Maude, Steven; Aggeli, Amalia; Nelson, Andrew

    2009-03-01

    Studies of beta-sheet peptide/phospholipid interactions are important for an understanding of the folding of beta-sheet-rich membrane proteins and the action of antimicrobial and toxic peptides. Further, self-assembling peptides have numerous applications in medicine and therefore an insight is required into the relation between peptide molecular structure and biomembrane activity. We previously developed one of the simplest known model peptide systems which, above a critical concentration (c*) in solution, undergoes nucleated one-dimensional self-assembly from a monomeric random coil into a hierarchy of well defined beta-sheet structures. Here we examine the effects of peptide aggregation, polarity, charge, and applied field on peptide interactions with dioleoyl phosphatidylcholine (DOPC) monolayers using electrochemical techniques. The interactions of six systematically altered 11 residue beta-sheet tape-forming peptides were investigated. The following findings with respect to 11 residue beta-sheet peptide-DOPC interaction arose from the study: (i) The solution monomer peptide species is the monolayer active moeity. (ii) Amphiphilic peptides are more monolayer active than polar peptides in the absence of applied electric field. (iii) Positive charge on amphiphilic peptides facilitates monolayer interaction in the absence of applied electric field. (iv) Negative applied electric field facilitates monolayer interaction with positively charged amphiphilic and polar peptides. (v) Neutral amphiphilic peptides permeabilize DOPC layers to ions to the greatest extent. (vi) The beta-sheet tape forming peptides are shown to be significantly less monolayer disruptive than antimicrobial peptides. These conclusions will greatly contribute to the rational design of new peptide-based biomaterials and biosensors.

  7. A recipe for designing water-soluble, beta-sheet-forming peptides.

    PubMed Central

    Mayo, K. H.; Ilyina, E.; Park, H.

    1996-01-01

    Based on observations of solubility and folding properties of peptide 33-mers derived from the beta-sheet domains of platelet factor-4 (PF4), interleukin-8 (IL-8), and growth related protein (Gro-alpha), as well as other beta-sheet-forming peptides, general guidelines have been developed to aid in the design of water soluble, self-association-induced beta-sheet-forming peptides. CD, 1H-NMR, and pulsed field gradient NMR self-diffusion measurements have been used to assess the degree of folding and state of aggregation. PF4 peptide forms native-like beta-sheet tetramers and is sparingly soluble above pH 6. IL-8 peptide is insoluble between pH 4.5 and pH 7.5, yet forms stable, native-like beta-sheet dimers at higher pH. Gro-alpha peptide is soluble at all pH values, yet displays no discernable beta-sheet structure even when diffusion data indicate dimer-tetramer aggregation. A recipe used in the de novo design of water-soluble beta-sheet-forming peptides calls for the peptide to contain 40-50% hydrophobic residues, usually aliphatic ones (I, L, V, A, M) (appropriately paired and mostly but not always alternating with polar residues in the sheet sequence), a positively charged (K, R) to negatively charged (E, D) residue ratio between 4/2 and 6/2, and a noncharged polar residue (N, Q, T, S) composition of about 20% or less. Results on four de novo designed, 33-residue peptides are presented supporting this approach. Under near physiologic conditions, all four peptides are soluble, form beta-sheet structures to varying degrees, and self-associate. One peptide folds as a stable, compact beta-sheet tetramer, whereas the others are transient beta-sheet-containing aggregates. PMID:8819163

  8. Semantic information can facilitate covert face recognition in congenital prosopagnosia.

    PubMed

    Rivolta, Davide; Schmalzl, Laura; Coltheart, Max; Palermo, Romina

    2010-11-01

    People with congenital prosopagnosia have never developed the ability to accurately recognize faces. This single case investigation systematically investigates covert and overt face recognition in "C.," a 69 year-old woman with congenital prosopagnosia. Specifically, we: (a) describe the first assessment of covert face recognition in congenital prosopagnosia using multiple tasks; (b) show that semantic information can contribute to covert recognition; and (c) provide a theoretical explanation for the mechanisms underlying covert face recognition.

  9. Design and construction of an open multistranded beta-sheet polypeptide stabilized by a disulfide bridge.

    PubMed

    Venkatraman, Janani; Nagana Gowda, Gowda A; Balaram, Padmanabhan

    2002-05-01

    The design and characterization of an open eight-stranded beta-sheet in a synthetic, 2-fold symmetric 70-residue peptide is described. The design strategy involves the generation of a 35-residue four-stranded beta-sheet peptide in which successive hairpins are nucleated by appropriately positioned (D)Pro-Xxx sequences. Oxidative dimerization using a single Cys residue positioned at the center of the C-terminal strand results in a disulfide-bridged eight-stranded structure. Nuclear Overhauser effects firmly establish an eight-stranded beta-sheet in methanol. In water, the outer strands are frayed, but a well-defined four-stranded beta-sheet stabilized by a disulfide bridge and a hydrophobic cluster is determined from NMR data. Comparison of the precursor peptide with the disulfide-bridged dimer reveals considerable enhancement of beta-sheet content in the latter, suggesting that the disulfide cross-link is an effective strategy for the stabilization of beta-sheets.

  10. Precise assembly of complex beta sheet topologies from de novo designed building blocks

    PubMed Central

    King, Indigo Chris; Gleixner, James; Doyle, Lindsey; Kuzin, Alexandre; Hunt, John F; Xiao, Rong; Montelione, Gaetano T; Stoddard, Barry L; DiMaio, Frank; Baker, David

    2015-01-01

    Design of complex alpha-beta protein topologies poses a challenge because of the large number of alternative packing arrangements. A similar challenge presumably limited the emergence of large and complex protein topologies in evolution. Here, we demonstrate that protein topologies with six and seven-stranded beta sheets can be designed by insertion of one de novo designed beta sheet containing protein into another such that the two beta sheets are merged to form a single extended sheet, followed by amino acid sequence optimization at the newly formed strand-strand, strand-helix, and helix-helix interfaces. Crystal structures of two such designs closely match the computational design models. Searches for similar structures in the SCOP protein domain database yield only weak matches with different beta sheet connectivities. A similar beta sheet fusion mechanism may have contributed to the emergence of complex beta sheets during natural protein evolution. DOI: http://dx.doi.org/10.7554/eLife.11012.001 PMID:26650357

  11. Orthographic Facilitation in Chinese Spoken Word Recognition: An ERP Study

    ERIC Educational Resources Information Center

    Zou, Lijuan; Desroches, Amy S.; Liu, Youyi; Xia, Zhichao; Shu, Hua

    2012-01-01

    Orthographic influences in spoken word recognition have been previously examined in alphabetic languages. However, it is unknown whether orthographic information affects spoken word recognition in Chinese, which has a clean dissociation between orthography (O) and phonology (P). The present study investigated orthographic effects using event…

  12. Spinal Anesthesia Facilitates the Early Recognition of TUR Syndrome

    PubMed Central

    McGowan-Smyth, Sam; Vasdev, Nikhil; Gowrie-Mohan, Shan

    2016-01-01

    . Conclusion The features most associated with the early presentation of TUR syndrome require the patient to be conscious for detection. The use of spinal anaesthesia is therefore desirable to facilitate its early recognition. PMID:27390576

  13. Structural characterization of adsorbed helical and beta-sheet peptides

    NASA Astrophysics Data System (ADS)

    Samuel, Newton Thangadurai

    Adsorbed peptides on surfaces have potential applications in the fields of biomaterials, tissue engineering, peptide microarrays and nanobiotechnology. The surface region, the "biomolecular interface" between a material and the biological environment, plays a crucial role in these applications. As a result, characterization of adsorbed peptide structure, especially with respect to identity, concentration, spatial distribution, conformation and orientation, is important. The present research employs NEXAFS (near-edge X-ray absorption fine structure spectroscopy) and SFG (sum frequency generation spectroscopy) to provide information about the adsorbed peptide structure. Soft X-ray NEXAFS is a synchrotron-based technique which typically utilizes polarized X-rays to interrogate surfaces under ultra-high vacuum conditions. SFG is a non-linear optical technique which utilizes a combination of a fixed visible and a tunable infrared laser beams to generate a surface-vibrational spectrum of surface species. SFG has the added advantage of being able to directly analyze the surface-structure at the solid-liquid interface. The main goals of the present research were twofold: characterize the structure of adsorbed peptides (1) ex situ using soft X-ray NEXAFS, and (2) in situ using non-linear laser spectroscopy (SFG). Achieving the former goal involved first developing a comprehensive characterization of the carbon, nitrogen and oxygen k-edge NEXAFS spectra for amino acids, and then using a series of helical and beta-sheet peptides to demonstrate the sensitivity of polarization-dependent NEXAFS to secondary structure of adsorbed peptides. Characterizing the structure of adsorbed peptides in situ using SFG involved developing a model system to probe the solid-liquid interface in situ; demonstrating the ability to probe the molecular interactions and adsorbed secondary structure; following the time-dependent ordering of the adsorbed peptides; and establishing the ability to obtain

  14. Mechanical energy transfer and dissipation in fibrous beta-sheet-rich proteins.

    PubMed

    Xu, Zhiping; Buehler, Markus J

    2010-06-01

    Mechanical properties of structural protein materials are crucial for our understanding of biological processes and disease states. Through utilization of molecular simulation based on stress wave tracking, we investigate mechanical energy transfer processes in fibrous beta-sheet-rich proteins that consist of highly ordered hydrogen bond (H-bond) networks. By investigating four model proteins including two morphologies of amyloids, beta solenoids, and silk beta-sheet nanocrystals, we find that all beta-sheet-rich protein fibrils provide outstanding elastic moduli, where the silk nanocrystal reaches the highest value of ≈40 GPa. However, their capacities to dissipate mechanical energy differ significantly and are controlled strongly by the underlying molecular structure of H-bond network. Notably, silk beta-sheet nanocrystals feature a ten times higher energy damping coefficient than others, owing to flexible intrastrand motions in the transverse directions. The results demonstrate a unique feature of silk nanocrystals, their capacity to simultaneously provide extreme stiffness and energy dissipation capacity. Our results could help one to explain the remarkable properties of silks from an atomistic and molecular perspective, in particular its great toughness and energy dissipation capacity, and may enable the design of multifunctional nanomaterials with outstanding stiffness, strength, and impact resistance.

  15. Engineering of betabellin 14D: disulfide-induced folding of a beta-sheet protein.

    PubMed Central

    Yan, Y.; Erickson, B. W.

    1994-01-01

    The betabellin target structure consists of 2 32-residue beta sheets packed against each other by hydrophobic interactions. We have designed, chemically synthesized, and biophysically characterized betabellin 14S, a single chain, and betabellin 14D, the disulfide-bridged double chain. The 32-residue nongenetic betabellin-14 chain (HSLTASIkaLTIHVQakTATCQVkaYTVHISE, a = D-Ala, k = D-Lys) has a palindromic pattern of polar (p), nonpolar (n), end (e), and beta-turn (t,r) residues (epnpnpnttnpnpnprrpnpnpnttnpnpnpe). Each half contains the same 14-residue palindromic pattern (underlined). Pairs of D-amino acid residues are used to favor formation of inverse-common (type-I') beta turns. In water at pH 6.5, the single chain of betabellin 14S is not folded, but the disulfide-linked betabellin 14D is folded into a stable beta-sheet structure. Thus, folding of the covalent dimer beta-bellin 14D is induced by formation of the single interchain disulfide bond. The binary pattern of alternating polar and nonpolar residues of its beta-sheets is not sufficient to induce folding. Betabellin 14D is a very water-soluble (10 mg/mL), small (64 residues), nongenetic (12 D residues) beta-sheet protein with properties (well-dispersed proton NMR resonances; Tm = 58 degrees C and delta Hm = 106 kcal/mol at pH 5.5) like those of a native protein structure. PMID:7920252

  16. Early recurrent feedback facilitates visual object recognition under challenging conditions

    PubMed Central

    Wyatte, Dean; Jilk, David J.; O'Reilly, Randall C.

    2014-01-01

    Standard models of the visual object recognition pathway hold that a largely feedforward process from the retina through inferotemporal cortex leads to object identification. A subsequent feedback process originating in frontoparietal areas through reciprocal connections to striate cortex provides attentional support to salient or behaviorally-relevant features. Here, we review mounting evidence that feedback signals also originate within extrastriate regions and begin during the initial feedforward process. This feedback process is temporally dissociable from attention and provides important functions such as grouping, associational reinforcement, and filling-in of features. Local feedback signals operating concurrently with feedforward processing are important for object identification in noisy real-world situations, particularly when objects are partially occluded, unclear, or otherwise ambiguous. Altogether, the dissociation of early and late feedback processes presented here expands on current models of object identification, and suggests a dual role for descending feedback projections. PMID:25071647

  17. The Promiscuity of [beta]-Strand Pairing Allows for Rational Design of [beta]-Sheet Face Inversion

    SciTech Connect

    Makabe, Koki; Koide, Shohei

    2009-06-17

    Recent studies suggest the dominant role of main-chain H-bond formation in specifying {beta}-sheet topology. Its essentially sequence-independent nature implies a large degree of freedom in designing {beta}-sheet-based nanomaterials. Here we show rational design of {beta}-sheet face inversions by incremental deletions of {beta}-strands from the single-layer {beta}-sheet of Borrelia outer surface protein A. We show that a {beta}-sheet structure can be maintained when a large number of native contacts are removed and that one can design large-scale conformational transitions of a {beta}-sheet such as face inversion by exploiting the promiscuity of strand-strand interactions. High-resolution X-ray crystal structures confirmed the success of the design and supported the importance of main-chain H-bonds in determining {beta}-sheet topology. This work suggests a simple but effective strategy for designing and controlling nanomaterials based on {beta}-rich peptide self-assemblies.

  18. Dissociation of rapid response learning and facilitation in perceptual and conceptual networks of person recognition.

    PubMed

    Valt, Christian; Klein, Christoph; Boehm, Stephan G

    2015-08-01

    Repetition priming is a prominent example of non-declarative memory, and it increases the accuracy and speed of responses to repeatedly processed stimuli. Major long-hold memory theories posit that repetition priming results from facilitation within perceptual and conceptual networks for stimulus recognition and categorization. Stimuli can also be bound to particular responses, and it has recently been suggested that this rapid response learning, not network facilitation, provides a sound theory of priming of object recognition. Here, we addressed the relevance of network facilitation and rapid response learning for priming of person recognition with a view to advance general theories of priming. In four experiments, participants performed conceptual decisions like occupation or nationality judgments for famous faces. The magnitude of rapid response learning varied across experiments, and rapid response learning co-occurred and interacted with facilitation in perceptual and conceptual networks. These findings indicate that rapid response learning and facilitation in perceptual and conceptual networks are complementary rather than competing theories of priming. Thus, future memory theories need to incorporate both rapid response learning and network facilitation as individual facets of priming.

  19. Thermally Induced Alpha-Helix to Beta-Sheet Transition in Regenerated Silk Fibers and Films

    SciTech Connect

    Drummy,L.; Phillips, D.; Stone, M.; Farmer, B.; Naik, R.

    2005-01-01

    The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study. Modulated differential scanning calorimetry (DSC) of the films showed an endothermic melting peak followed by an exothermic crystallization peak, both occurring near 140 degrees C. Oriented fibers were also produced that displayed this helical molecular conformation. Subsequent heating above the structural transition temperature produced oriented beta-sheet fibers very similar in structure to B. mori cocoon fibers. Heat treatment of silk films at temperatures well below their degradation temperature offers a controllable route to materials with well-defined structures and mechanical behavior.

  20. Facilitating Use of Speech Recognition Software for People with Disabilities: A Comparison of Three Treatments

    ERIC Educational Resources Information Center

    Hird, Kathryn; Hennessey, Neville W.

    2007-01-01

    This study examined the relative benefit of three interventions (i.e. physiological, behavioural, and pragmatic) designed to facilitate speech recognition software use. Participants were 15 adults with dysarthria associated with a variety of aetiological conditions, including cerebral palsy, Parkinson's disease, and motor neuron disease. Results…

  1. Reversible thermal denaturation of a 60-kDa genetically engineered beta-sheet polypeptide.

    PubMed

    Lednev, Igor K; Ermolenkov, Vladimir V; Higashiya, Seiichiro; Popova, Ludmila A; Topilina, Natalya I; Welch, John T

    2006-11-15

    A de novo 687-amino-acid residue polypeptide with a regular 32-amino-acid repeat sequence, (GA)(3)GY(GA)(3)GE(GA)(3)GH(GA)(3)GK, forms large beta-sheet assemblages that exhibit remarkable folding properties and, as well, form fibrillar structures. This construct is an excellent tool to explore the details of beta-sheet formation yielding intimate folding information that is otherwise difficult to obtain and may inform folding studies of naturally occurring materials. The polypeptide assumes a fully folded antiparallel beta-sheet/turn structure at room temperature, and yet is completely and reversibly denatured at 125 degrees C, adopting a predominant polyproline II conformation. Deep ultraviolet Raman spectroscopy indicated that melting/refolding occurred without any spectroscopically distinct intermediates, yet the relaxation kinetics depend on the initial polypeptide state, as would be indicative of a non-two-state process. Thermal denaturation and refolding on cooling appeared to be monoexponential with characteristic times of approximately 1 and approximately 60 min, respectively, indicating no detectable formation of hairpin-type nuclei in the millisecond timescale that could be attributed to nonlocal "nonnative" interactions. The polypeptide folding dynamics agree with a general property of beta-sheet proteins, i.e., initial collapse precedes secondary structure formation. The observed folding is much faster than expected for a protein of this size and could be attributed to a less frustrated free-energy landscape funnel for folding. The polypeptide sequence suggests an important balance between the absence of strong nonnative contacts (salt bridges or hydrophobic collapse) and limited repulsion of charged side chains. PMID:16891363

  2. Self-recognition in corals facilitates deep-sea habitat engineering.

    PubMed

    Hennige, S J; Morrison, C L; Form, A U; Büscher, J; Kamenos, N A; Roberts, J M

    2014-01-01

    The ability of coral reefs to engineer complex three-dimensional habitats is central to their success and the rich biodiversity they support. In tropical reefs, encrusting coralline algae bind together substrates and dead coral framework to make continuous reef structures, but beyond the photic zone, the cold-water coral Lophelia pertusa also forms large biogenic reefs, facilitated by skeletal fusion. Skeletal fusion in tropical corals can occur in closely related or juvenile individuals as a result of non-aggressive skeletal overgrowth or allogeneic tissue fusion, but contact reactions in many species result in mortality if there is no 'self-recognition' on a broad species level. This study reveals areas of 'flawless' skeletal fusion in Lophelia pertusa, potentially facilitated by allogeneic tissue fusion, are identified as having small aragonitic crystals or low levels of crystal organisation, and strong molecular bonding. Regardless of the mechanism, the recognition of 'self' between adjacent L. pertusa colonies leads to no observable mortality, facilitates ecosystem engineering and reduces aggression-related energetic expenditure in an environment where energy conservation is crucial. The potential for self-recognition at a species level, and subsequent skeletal fusion in framework-forming cold-water corals is an important first step in understanding their significance as ecological engineers in deep-seas worldwide.

  3. Designing biomaterials exploiting beta-sheet forming peptides self-assembly

    NASA Astrophysics Data System (ADS)

    Saiani, Alberto

    2013-03-01

    The use of non-covalent self-assembly to construct materials has become a prominent strategy in material science offering practical routes for the construction of increasingly functional materials for a variety of applications ranging from electronic to biotechnology. A variety of molecular building blocks can be used for this purpose, one such block that has attracted considerable attention are de-novo designed peptides. The library of 20 natural amino acids offers the ability to play with the intrinsic properties of the peptide such as structure, hydrophobicity, charge and functionality allowing the design of materials with a wide range of properties. The beta-sheet motif is of particular interest as short peptides can be designed to form beta-sheet rich fibres that entangle and consequently form hydrogels. These hydrogels can be further functionalised using specific biological signals or drugs by synthesising functionalised peptides that are incorporated into the hydrogel network during the self-assembling process. This functionalisation approach is very attractive has it does not require any chemistry avoiding therefore the use of additional potentially toxic chemicals. It also offers the possibility to introduce multiple functionalities in a straightforward fashion. The hydrogels can also be made responsive through the use of enzymatic catalysis and/or conjugation with responsive polymers. In this presentation we will discuss the design opportunities offered by these peptides to create new functional biomaterials.

  4. Characteristics of Amyloid-Related Oligomers Revealed by Crystal Structures of Macrocyclic [beta]-Sheet Mimics

    SciTech Connect

    Liu, Cong; Sawaya, Michael R.; Cheng, Pin-Nan; Zheng, Jing; Nowick, James S.; Eisenberg, David

    2011-09-20

    Protein amyloid oligomers have been strongly linked to amyloid diseases and can be intermediates to amyloid fibers. {beta}-Sheets have been identified in amyloid oligomers. However, because of their transient and highly polymorphic properties, the details of their self-association remain elusive. Here we explore oligomer structure using a model system: macrocyclic peptides. Key amyloidogenic sequences from A{beta} and tau were incorporated into macrocycles, thereby restraining them to {beta}-strands, but limiting the growth of the oligomers so they may crystallize and cannot fibrillate. We determined the atomic structures for four such oligomers, and all four reveal tetrameric interfaces in which {beta}-sheet dimers pair together by highly complementary, dry interfaces, analogous to steric zippers found in fibers, suggesting a common structure for amyloid oligomers and fibers. In amyloid fibers, the axes of the paired sheets are either parallel or antiparallel, whereas the oligomeric interfaces display a variety of sheet-to-sheet pairing angles, offering a structural explanation for the heterogeneity of amyloid oligomers.

  5. Conformational diversity in prion protein variants influences intermolecular [beta]-sheet formation

    SciTech Connect

    Lee, Seungjoo; Antony, Lizamma; Hartmann, Rune; Knaus, Karen J.; Surewicz, Krystyna; Surewicz, Witold K.; Yee, Vivien C.

    2010-04-19

    A conformational transition of normal cellular prion protein (PrP{sup C}) to its pathogenic form (PrP{sup Sc}) is believed to be a central event in the transmission of the devastating neurological diseases known as spongiform encephalopathies. The common methionine/valine polymorphism at residue 129 in the PrP influences disease susceptibility and phenotype. We report here seven crystal structures of human PrP variants: three of wild-type (WT) PrP containing V129, and four of the familial variants D178N and F198S, containing either M129 or V129. Comparison of these structures with each other and with previously published WT PrP structures containing M129 revealed that only WT PrPs were found to crystallize as domain-swapped dimers or closed monomers; the four mutant PrPs crystallized as non-swapped dimers. Three of the four mutant PrPs aligned to form intermolecular {beta}-sheets. Several regions of structural variability were identified, and analysis of their conformations provides an explanation for the structural features, which can influence the formation and conformation of intermolecular {beta}-sheets involving the M/V129 polymorphic residue.

  6. Strength limit of entropic elasticity in beta-sheet protein domains

    NASA Astrophysics Data System (ADS)

    Keten, Sinan; Buehler, Markus J.

    2008-12-01

    Elasticity and strength of individual beta-sheet protein domains govern key biological functions and the mechanical properties of biopolymers including spider silk, amyloids, and muscle fibers. The worm-like-chain (WLC) model is commonly used to describe the entropic elasticity of polypeptides and other biomolecules. However, force spectroscopy experiments have shown pronounced deviations from the ideal WLC behavior, leading to controversial views about the appropriate elastic description of proteins at nanoscale. Here we report a simple model that explains the physical mechanism that leads to the breakdown of the WLC idealization in experiments by using only two generic parameters of the protein domain, the H-bond energy and the protein backbone’s persistence length. We show that a rupture initiation condition characterized by the free energy release rate of H-bonds characterizes the limit of WLC entropic elasticity of beta-sheet protein domains and the onset of rupture. Our findings reveal that strength and elasticity are coupled and cannot be treated separately. The predictions of the model are compared with atomic force microscopy experiments of protein rupture.

  7. Hemi-methylated DNA opens a closed conformation of UHRF1 to facilitate its histone recognition

    PubMed Central

    Fang, Jian; Cheng, Jingdong; Wang, Jiaolong; Zhang, Qiao; Liu, Mengjie; Gong, Rui; Wang, Ping; Zhang, Xiaodan; Feng, Yangyang; Lan, Wenxian; Gong, Zhou; Tang, Chun; Wong, Jiemin; Yang, Huirong; Cao, Chunyang; Xu, Yanhui

    2016-01-01

    UHRF1 is an important epigenetic regulator for maintenance DNA methylation. UHRF1 recognizes hemi-methylated DNA (hm-DNA) and trimethylation of histone H3K9 (H3K9me3), but the regulatory mechanism remains unknown. Here we show that UHRF1 adopts a closed conformation, in which a C-terminal region (Spacer) binds to the tandem Tudor domain (TTD) and inhibits H3K9me3 recognition, whereas the SET-and-RING-associated (SRA) domain binds to the plant homeodomain (PHD) and inhibits H3R2 recognition. Hm-DNA impairs the intramolecular interactions and promotes H3K9me3 recognition by TTD–PHD. The Spacer also facilitates UHRF1–DNMT1 interaction and enhances hm-DNA-binding affinity of the SRA. When TTD–PHD binds to H3K9me3, SRA-Spacer may exist in a dynamic equilibrium: either recognizes hm-DNA or recruits DNMT1 to chromatin. Our study reveals the mechanism for regulation of H3K9me3 and hm-DNA recognition by URHF1. PMID:27045799

  8. Hemi-methylated DNA opens a closed conformation of UHRF1 to facilitate its histone recognition

    NASA Astrophysics Data System (ADS)

    Fang, Jian; Cheng, Jingdong; Wang, Jiaolong; Zhang, Qiao; Liu, Mengjie; Gong, Rui; Wang, Ping; Zhang, Xiaodan; Feng, Yangyang; Lan, Wenxian; Gong, Zhou; Tang, Chun; Wong, Jiemin; Yang, Huirong; Cao, Chunyang; Xu, Yanhui

    2016-04-01

    UHRF1 is an important epigenetic regulator for maintenance DNA methylation. UHRF1 recognizes hemi-methylated DNA (hm-DNA) and trimethylation of histone H3K9 (H3K9me3), but the regulatory mechanism remains unknown. Here we show that UHRF1 adopts a closed conformation, in which a C-terminal region (Spacer) binds to the tandem Tudor domain (TTD) and inhibits H3K9me3 recognition, whereas the SET-and-RING-associated (SRA) domain binds to the plant homeodomain (PHD) and inhibits H3R2 recognition. Hm-DNA impairs the intramolecular interactions and promotes H3K9me3 recognition by TTD-PHD. The Spacer also facilitates UHRF1-DNMT1 interaction and enhances hm-DNA-binding affinity of the SRA. When TTD-PHD binds to H3K9me3, SRA-Spacer may exist in a dynamic equilibrium: either recognizes hm-DNA or recruits DNMT1 to chromatin. Our study reveals the mechanism for regulation of H3K9me3 and hm-DNA recognition by URHF1.

  9. Hemi-methylated DNA opens a closed conformation of UHRF1 to facilitate its histone recognition.

    PubMed

    Fang, Jian; Cheng, Jingdong; Wang, Jiaolong; Zhang, Qiao; Liu, Mengjie; Gong, Rui; Wang, Ping; Zhang, Xiaodan; Feng, Yangyang; Lan, Wenxian; Gong, Zhou; Tang, Chun; Wong, Jiemin; Yang, Huirong; Cao, Chunyang; Xu, Yanhui

    2016-01-01

    UHRF1 is an important epigenetic regulator for maintenance DNA methylation. UHRF1 recognizes hemi-methylated DNA (hm-DNA) and trimethylation of histone H3K9 (H3K9me3), but the regulatory mechanism remains unknown. Here we show that UHRF1 adopts a closed conformation, in which a C-terminal region (Spacer) binds to the tandem Tudor domain (TTD) and inhibits H3K9me3 recognition, whereas the SET-and-RING-associated (SRA) domain binds to the plant homeodomain (PHD) and inhibits H3R2 recognition. Hm-DNA impairs the intramolecular interactions and promotes H3K9me3 recognition by TTD-PHD. The Spacer also facilitates UHRF1-DNMT1 interaction and enhances hm-DNA-binding affinity of the SRA. When TTD-PHD binds to H3K9me3, SRA-Spacer may exist in a dynamic equilibrium: either recognizes hm-DNA or recruits DNMT1 to chromatin. Our study reveals the mechanism for regulation of H3K9me3 and hm-DNA recognition by URHF1.

  10. Spectroscopic studies of structural changes in two beta-sheet-forming peptides show an ensemble of structures that unfold noncooperatively.

    PubMed

    Kuznetsov, Serguei V; Hilario, Jovencio; Keiderling, Timothy A; Ansari, Anjum

    2003-04-22

    A characterization of the conformation and stability of model peptide systems that form beta-sheets in aqueous solutions is considerably important in gaining insights into the mechanism of beta-sheet formation in proteins. We have characterized the conformation and equilibrium folding and unfolding of two 20-residue peptides whose NMR spectra suggest a three-stranded beta-sheet topology in aqueous solution: Betanova [Kortemme, T., Ramirez-Alvarado, M., and Serrano, L. (1998) Science 281, 253-256] and (D)P(D)P with d-Pro-Gly segments at the turns [Schenck, H. L., and Gellman, S. H. (1998) J. Am. Chem. Soc. 120, 4869-4870]. Both circular dichroism (CD) and infrared measurements indicate only 20-26% beta-sheet-like structure at 5 degrees C for Betanova and 42-59% beta-sheet for (D)P(D)P. For both peptides, the CD and infrared spectra change nearly linearly with increasing temperatures (or urea concentrations) and lack a sigmoidal signature characteristic of cooperative unfolding. Fluorescence resonance energy transfer (FRET) measurements between donor and acceptor molecules attached to the two ends confirm that Betanova is largely unstructured even at 10 degrees C; the average end-to-end distance estimated from FRET is closer to that of a random coil than a structured beta-sheet. In (D)P(D)P, the FRET results indicate a more compact structure that remains compact even at high temperatures (approximately 80 degrees C) or high urea concentrations (approximately 8 M). These results indicate that both these peptides access an ensemble of conformations at all temperatures or denaturant concentrations, with no significant free energy barrier separating the "folded" and "unfolded" conformations.

  11. On the facilitative effects of face motion on face recognition and its development

    PubMed Central

    Xiao, Naiqi G.; Perrotta, Steve; Quinn, Paul C.; Wang, Zhe; Sun, Yu-Hao P.; Lee, Kang

    2014-01-01

    For the past century, researchers have extensively studied human face processing and its development. These studies have advanced our understanding of not only face processing, but also visual processing in general. However, most of what we know about face processing was investigated using static face images as stimuli. Therefore, an important question arises: to what extent does our understanding of static face processing generalize to face processing in real-life contexts in which faces are mostly moving? The present article addresses this question by examining recent studies on moving face processing to uncover the influence of facial movements on face processing and its development. First, we describe evidence on the facilitative effects of facial movements on face recognition and two related theoretical hypotheses: the supplementary information hypothesis and the representation enhancement hypothesis. We then highlight several recent studies suggesting that facial movements optimize face processing by activating specific face processing strategies that accommodate to task requirements. Lastly, we review the influence of facial movements on the development of face processing in the first year of life. We focus on infants' sensitivity to facial movements and explore the facilitative effects of facial movements on infants' face recognition performance. We conclude by outlining several future directions to investigate moving face processing and emphasize the importance of including dynamic aspects of facial information to further understand face processing in real-life contexts. PMID:25009517

  12. On the facilitative effects of face motion on face recognition and its development.

    PubMed

    Xiao, Naiqi G; Perrotta, Steve; Quinn, Paul C; Wang, Zhe; Sun, Yu-Hao P; Lee, Kang

    2014-01-01

    For the past century, researchers have extensively studied human face processing and its development. These studies have advanced our understanding of not only face processing, but also visual processing in general. However, most of what we know about face processing was investigated using static face images as stimuli. Therefore, an important question arises: to what extent does our understanding of static face processing generalize to face processing in real-life contexts in which faces are mostly moving? The present article addresses this question by examining recent studies on moving face processing to uncover the influence of facial movements on face processing and its development. First, we describe evidence on the facilitative effects of facial movements on face recognition and two related theoretical hypotheses: the supplementary information hypothesis and the representation enhancement hypothesis. We then highlight several recent studies suggesting that facial movements optimize face processing by activating specific face processing strategies that accommodate to task requirements. Lastly, we review the influence of facial movements on the development of face processing in the first year of life. We focus on infants' sensitivity to facial movements and explore the facilitative effects of facial movements on infants' face recognition performance. We conclude by outlining several future directions to investigate moving face processing and emphasize the importance of including dynamic aspects of facial information to further understand face processing in real-life contexts. PMID:25009517

  13. Evidence for Novel [beta]-Sheet Structures in Iowa Mutant [beta]-Amyloid Fibrils

    SciTech Connect

    Tycko, Robert; Sciarretta, Kimberly L.; Orgel, Joseph P.R.O.; Meredith, Stephen C.

    2009-07-24

    Asp23-to-Asn mutation within the coding sequence of {beta}-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-A{beta}40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-A{beta}40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10{sup -3} min{sup -1} and 1.07 x 10{sup -4} min{sup -1} for D23N-A{beta}40 and the wild-type peptide WT-A{beta}40, respectively) and without a lag phase. Electron microscopy shows that D23N-A{beta}40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-{beta} pattern, with a sharp reflection at 4.7 {angstrom} and a broad reflection at 9.4 {angstrom}, which is notably smaller than the value for WT-A{beta}40 fibrils (10.4 {angstrom}). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-A{beta}40 fibrils containing the in-register, parallel {beta}-sheet structure commonly found in WT-A{beta}40 fibrils and most other amyloid fibrils. Antiparallel {beta}-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through 13C-13C and 15N-13C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-A{beta}40 fibrils and the unusual vasculotropic clinical picture in these patients.

  14. Evidence for novel beta-sheet structures in Iowa mutant beta-amyloid fibrils.

    PubMed

    Tycko, Robert; Sciarretta, Kimberly L; Orgel, Joseph P R O; Meredith, Stephen C

    2009-07-01

    Asp23-to-Asn mutation within the coding sequence of beta-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-Abeta40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-Abeta40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10(-3) min(-1) and 1.07 x 10(-4) min(-1) for D23N-Abeta40 and the wild-type peptide WT-Abeta40, respectively) and without a lag phase. Electron microscopy shows that D23N-Abeta40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-beta pattern, with a sharp reflection at 4.7 A and a broad reflection at 9.4 A, which is notably smaller than the value for WT-Abeta40 fibrils (10.4 A). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-Abeta40 fibrils containing the in-register, parallel beta-sheet structure commonly found in WT-Abeta40 fibrils and most other amyloid fibrils. Antiparallel beta-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through (13)C-(13)C and (15)N-(13)C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-Abeta40 fibrils and the unusual vasculotropic clinical picture in these patients.

  15. sup 1 H NMR identification of a. beta. -sheet structure and description of folding topology in putidaredoxin

    SciTech Connect

    Pochapsky, T.C.; Ye, Xiao Mei )

    1991-04-23

    Putidaredoxin (Pdx), a 106-residue globular protein consisting of a single polypeptide chain and a (2Fe-2S) cluster, is the physiological reductant of P-450{sub cam}, which in turn catalyzes the monohydroxylation of camphor by molecular oxygen. No crystal structure has been obtained for Pdx or for any closely homologous protein. The application of two-dimensional {sup 1}H NMR methods to the problem of structure determination in Pdx is reported. A {beta}-sheet consisting of five short strands and one {beta}-turn has been identified from distinctive nuclear Overhauser effect patterns. All of the backbone resonances and a majority of the side-chain resonances corresponding to protons in the {beta}-sheet have been assigned sequence specifically. The sheet contains one parallel and three antiparallel strand orientations. Hydrophobic side chains in the {beta}-sheet face primarily toward the protein interior, except for a group of three valine side chains that are apparently solvent exposed. The potential significance of this hydrophobic patch in terms of biological activity is discussed. The folding topology, as determined by the constraints of the {beta}-sheet, is compared with that of other (2Fe-2S) proteins for which folding topologies are known.

  16. Structural principles for the propeller assembly of beta-sheets: the preference for seven-fold symmetry.

    PubMed

    Murzin, A G

    1992-10-01

    Twisted beta-sheets, packed face to face, may be arranged in circular formation like blades of a propeller or turbine. This beta-propeller fold has been found in three proteins: that in neuraminidase consists of six beta-sheets while those in methylamine dehydrogenase and galactose oxidase are composed of seven beta-sheets. A model for multisheet packing in the beta-propeller fold is proposed. This model gives both geometrical parameters of the beta-propellers composed of different numbers of sheets and patterns of residue packing at their sheet-to-sheet interfaces. All the known beta-propeller structures have been analyzed, and the observed geometries and residue packing are found to be in good agreement with those predicted by models. It is shown that unusual seven-fold symmetry is preferable to six- or eight-fold symmetry for propeller-like multi-sheet assembly. According to the model, a six-beta-sheet propeller has to have predominantly small residues in the beta-strands closed to its six-fold axis, but no strong sequence constraints are necessary for a seven-fold beta-propeller. PMID:1409568

  17. Copper abolishes the beta-sheet secondary structure of preformed amyloid fibrils of amyloid-beta(42).

    PubMed

    House, Emily; Mold, Matthew; Collingwood, Joanna; Baldwin, Alex; Goodwin, Steven; Exley, Christopher

    2009-01-01

    The observation of the co-deposition of metals and amyloid-beta(42) (Abeta(42)) in brain tissue in Alzheimer's disease prompted myriad investigations into the role played by metals in the precipitation of this peptide. Copper is bound by monomeric Abeta(12) and upon precipitation of the copper-peptide complex thereby prevents Abeta(42) from adopting a beta-sheet secondary structure. Copper is also bound by beta-sheet conformers of Abeta(42), and herein we have investigated how this interaction affects the conformation of the precipitated peptide. Copper significantly reduced the thioflavin T fluorescence of aged, fibrillar Abeta(42) with, for example, a 20-fold excess of the metal resulting in a ca 90% reduction in thioflavin T fluorescence. Transmission electron microscopy showed that copper significantly reduced the quantities of amyloid fibrils while Congo red staining and polarized light demonstrated a copper-induced abolition of apple-green birefringence. Microscopy under cross-polarized light also revealed the first observation of spherulites of Abeta(42). The size and appearance of these amyloid structures were found to be very similar to spherulites identified in Alzheimer's disease tissue. The combined results of these complementary methods strongly suggested that copper abolished the beta-sheet secondary structure of pre-formed, aged amyloid fibrils of Abeta(42). Copper may protect against the presence of beta-sheets of Abeta(42) in vivo, and its binding by fibrillar Abeta(42) could have implications for Alzheimer's disease therapy. PMID:19749401

  18. Amide-I and -II vibrations of the cyclic beta-sheet model peptide gramicidin S in the gas phase.

    PubMed

    Kupser, Peter; Pagel, Kevin; Oomens, Jos; Polfer, Nick; Koksch, Beate; Meijer, Gerard; von Helden, Gert

    2010-02-17

    In the condensed phase, the peptide gramicidin S is often considered as a model system for a beta-sheet structure. Here, we investigate gramicidin S free of any influences of the environment by measuring the mid-IR spectra of doubly protonated (deuterated) gramicidin S in the gas phase. In the amide I (i.e., C=O stretch) region, the spectra show a broad split peak between 1580 and 1720 cm(-1). To deduce structural information, the conformational space has been searched using molecular dynamics methods and several structural candidates have been further investigated at the density functional level. The calculations show the importance of the interactions of the charged side-chains with the backbone, which is responsible for the lower frequency part of the amide I peak. When this interaction is inhibited via complexation with two 18-crown-6 molecules, the amide I peak narrows and shows two maxima at 1653 and 1680 cm(-1). A comparison to calculations shows that for this complexed ion, four C=O groups are in an antiparallel beta-sheet arrangement. Surprisingly, an analysis of the calculated spectra shows that these beta-sheet C=O groups give rise to the vibrations near 1680 cm(-1). This is in sharp contrast to expectations based on values for the condensed phase, where resonances of beta-sheet sections are thought to occur near 1630 cm(-1). The difference between those values might be caused by interactions with the environment, as the condensed phase value is mostly deduced for beta-sheet sections that are embedded in larger proteins, that interact strongly with solvent or that are part of partially aggregated species.

  19. Factors contributing to decreased protein stability when aspartic acid residues are in {beta}-sheet regions.

    SciTech Connect

    Pokkuluri, P. R.; Cai, X.; Raffen, R.; Gu, M.; Stevens, F. J.; Schiffer, M.

    2002-07-01

    Asp residues are significantly under represented in {beta}-sheet regions of proteins, especially in the middle of {beta}-strands, as found by a number of studies using statistical, modeling, or experimental methods. To further understand the reasons for this under representation of Asp, we prepared and analyzed mutants of a {beta}-domain. Two Gln residues of the immunoglobulin light-chain variable domain (V{sub L}) of protein Len were replaced with Asp, and then the effects of these changes on protein stability and protein structure were studied. The replacement of Q38D, located at the end of a {beta}-strand, and that of Q89D, located in the middle of a {beta}-strand, reduced the stability of the parent immunoglobulin VL domain by 2.0 kcal/mol and 5.3 kcal/mol, respectively. Because the Q89D mutant of the wild-type V{sub L}-Len domain was too unstable to be expressed as a soluble protein, we prepared the Q89D mutant in a triple mutant background, V{sub L}-Len M4L/Y27dD/T94H, which was 4.2 kcal/mol more stable than the wild-type V{sub L}-Len domain. The structures of mutants V{sub L}-Len Q38D and V{sub L}-Len Q89D/M4L/Y27dD/T94H were determined by X-ray diffraction at 1.6 A resolution. We found no major perturbances in the structures of these QD mutant proteins relative to structures of the parent proteins. The observed stability changes have to be accounted for by cumulative effects of the following several factors: (1) by changes in main-chain dihedral angles and in side-chain rotomers, (2) by close contacts between some atoms, and, most significantly, (3) by the unfavorable electrostatic interactions between the Asp side chain and the carbonyls of the main chain. We show that the Asn side chain, which is of similar size but neutral, is less destabilizing. The detrimental effect of Asp within a {beta}-sheet of an immunoglobulin-type domain can have very serious consequences. A somatic mutation of a {beta}-strand residue to Asp could prevent the expression of the

  20. Collective oscillations and the linear and two-dimensional infrared spectra of inhomogeneous beta-sheets.

    PubMed

    Dijkstra, Arend G; Knoester, Jasper

    2005-05-19

    We numerically calculate the collective amide I oscillations and the associated linear and two-dimensional infrared (2DIR) spectra for model antiparallel beta-sheets and study the effect of inhomogeneity. To visualize the collective vibrational exciton states, a new method is introduced, which proves very useful in classifying the optically dominant states with respect to their symmetry properties and phase relations, even in the absence of exact symmetries. We find that energy (diagonal) and interaction (off-diagonal) disorder may have profoundly different effects on the main peaks in the linear spectrum. We also show that in the 2DIR spectra energy disorder leads to diagonal stretching of the diagonal peaks, while the cross-peaks are typically stretched more horizontally. This offers an explanation for the recently observed overall Z-shape in experimental spectra. Finally, we find that the anharmonic splitting between associated positive and negative features in the 2DIR spectra scales inversely proportionally with the exciton delocalization size imposed by the disorder, thus offering a spectroscopic ruler for this size. PMID:16852179

  1. Positive, but Not Negative, Facial Expressions Facilitate 3-Month-Olds' Recognition of an Individual Face

    ERIC Educational Resources Information Center

    Brenna, Viola; Proietti, Valentina; Montirosso, Rosario; Turati, Chiara

    2013-01-01

    The current study examined whether and how the presence of a positive or a negative emotional expression may affect the face recognition process at 3 months of age. Using a familiarization procedure, Experiment 1 demonstrated that positive (i.e., happiness), but not negative (i.e., fear and anger) facial expressions facilitate infants'…

  2. Deuterium exchange of alpha-helices and beta-sheets as monitored by electrospray ionization mass spectrometry.

    PubMed Central

    Wagner, D. S.; Melton, L. G.; Yan, Y.; Erickson, B. W.; Anderegg, R. J.

    1994-01-01

    Deuterium exchange was monitored by electrospray ionization mass spectrometry (ESI-MS) to study the slowly exchanging (hydrogen bonded) peptide hydrogens of several alpha-helical peptides and beta-sheet proteins. Polypeptides were synthetically engineered to have mainly disordered, alpha-helical, or beta-sheet structure. For 3 isomeric 31-residue alpha-helical peptides, the number of slowly exchanging hydrogens as measured by ESI-MS in 50% CF3CD2OD (pD 9.5) provided estimates of their alpha-helicities (26%, 40%, 94%) that agreed well with the values (17%, 34%, 98%) measured by circular dichroic spectroscopy in the same nondeuterated solvent. For 3 betabellins containing a pair of beta-sheets and a related disordered peptide, their order of structural stability (12D > 12S > 14D > 14S) shown by their deuterium exchange rates in 10% CD3OD/0.5% CD3CO2D (pD 3.8) as measured by ESI-MS was the same as their order of structural stability to unfolding with increasing temperature or guanidinium chloride concentration as measured by circular dichroic spectroscopy in water. Compared to monitoring deuterium exchange by proton NMR spectrometry, monitoring deuterium exchange by ESI-MS requires much less sample (1-50 micrograms), much shorter analysis time (10-90 min), and no chemical quenching of the exchange reaction. PMID:7987225

  3. Sequence specificity, statistical potentials, and three-dimensional structure prediction with self-correcting distance geometry calculations of beta-sheet formation in proteins.

    PubMed Central

    Zhu, H.; Braun, W.

    1999-01-01

    A statistical analysis of a representative data set of 169 known protein structures was used to analyze the specificity of residue interactions between spatial neighboring strands in beta-sheets. Pairwise potentials were derived from the frequency of residue pairs in nearest contact, second nearest and third nearest contacts across neighboring beta-strands compared to the expected frequency of residue pairs in a random model. A pseudo-energy function based on these statistical pairwise potentials recognized native beta-sheets among possible alternative pairings. The native pairing was found within the three lowest energies in 73% of the cases in the training data set and in 63% of beta-sheets in a test data set of 67 proteins, which were not part of the training set. The energy function was also used to detect tripeptides, which occur frequently in beta-sheets of native proteins. The majority of native partners of tripeptides were distributed in a low energy range. Self-correcting distance geometry (SECODG) calculations using distance constraints sets derived from possible low energy pairing of beta-strands uniquely identified the native pairing of the beta-sheet in pancreatic trypsin inhibitor (BPTI). These results will be useful for predicting the structure of proteins from their amino acid sequence as well as for the design of proteins containing beta-sheets. PMID:10048326

  4. Systemic administration of riluzole enhances recognition memory and facilitates extinction of fear memory in rats.

    PubMed

    Sugiyama, Azusa; Saitoh, Akiyoshi; Inagaki, Masatoshi; Oka, Jun-Ichiro; Yamada, Mitsuhiko

    2015-10-01

    Strategies to enhance recognition memory and facilitate extinction of fear memory have attracted increasing attention for enhancing the effectiveness of exposure therapy for anxiety disorders. Previously, we demonstrated that systemic administration of riluzole has clear anxiolytic-like effects, without impairing memory, in rats. In the present study, we examined whether riluzole could have therapeutic potential for anxiety disorders when combined with exposure therapy. Both riluzole and D-cycloserine enhanced recognition memory in the novel object recognition test and facilitated extinction learning in the contextual fear conditioning in rats. Interestingly, the facilitatory effect of riluzole on extinction learning was clearly observed even after a short re-exposure to the context, while D-cycloserine was ineffective at facilitating extinction when a short duration exposure session was given. In contrast, diazepam impaired both recognition memory and the extinction of fear memory. Our findings strongly suggest that systemic administration of riluzole may have therapeutic efficacy when combined with exposure therapy for treating a range of anxiety disorders. Clinical trials to examine the efficacy of riluzole in combination with exposure therapy in these patients are warranted.

  5. An investigation into IgE-facilitated allergen recognition and presentation by human dendritic cells

    PubMed Central

    2013-01-01

    Background Allergen recognition by dendritic cells (DCs) is a key event in the allergic cascade leading to production of IgE antibodies. C-type lectins, such as the mannose receptor and DC-SIGN, were recently shown to play an important role in the uptake of the house dust mite glycoallergen Der p 1 by DCs. In addition to mannose receptor (MR) and DC-SIGN the high and low affinity IgE receptors, namely FcϵRI and FcϵRII (CD23), respectively, have been shown to be involved in allergen uptake and presentation by DCs. Objectives This study aims at understanding the extent to which IgE- and IgG-facilitated Der p 1 uptake by DCs influence T cell polarisation and in particular potential bias in favour of Th2. We have addressed this issue by using two chimaeric monoclonal antibodies produced in our laboratory and directed against a previously defined epitope on Der p 1, namely human IgE 2C7 and IgG1 2C7. Results Flow cytometry was used to establish the expression patterns of IgE (FcϵRI and FcϵRII) and IgG (FcγRI) receptors in relation to MR on DCs. The impact of FcϵRI, FcϵRII, FcγRI and mannose receptor mediated allergen uptake on Th1/Th2 cell differentiation was investigated using DC/T cell co-culture experiments. Myeloid DCs showed high levels of FcϵRI and FcγRI expression, but low levels of CD23 and MR, and this has therefore enabled us to assess the role of IgE and IgG-facilitated allergen presentation in T cell polarisation with minimal interference by CD23 and MR. Our data demonstrate that DCs that have taken up Der p 1 via surface IgE support a Th2 response. However, no such effect was demonstrable via surface IgG. Conclusions IgE bound to its high affinity receptor plays an important role in Der p 1 uptake and processing by peripheral blood DCs and in Th2 polarisation of T cells. PMID:24330349

  6. Structure of a Nudix protein from Pyrobaculum aerophilum reveals a dimer with two intersubunit beta-sheets.

    PubMed

    Wang, Shuishu; Mura, Cameron; Sawaya, Michael R; Cascio, Duilio; Eisenberg, David

    2002-04-01

    Nudix proteins, formerly called MutT homolog proteins, are a large family of proteins that play an important role in reducing the accumulation of potentially toxic compounds inside the cell. They hydrolyze a wide variety of substrates that are mainly composed of a nucleoside diphosphate linked to some other moiety X and thus are called Nudix hydrolases. Here, the crystal structure of a Nudix hydrolase from the hyperthermophilic archaeon Pyrobaculum aerophilum is reported. The structure was determined by the single-wavelength anomalous scattering method with data collected at the peak anomalous wavelength of an iridium-derivatized crystal. It reveals an extensive dimer interface, with each subunit contributing two strands to the beta-sheet of the other subunit. Individual subunits consist of a mixed highly twisted and curved beta-sheet of 11 beta-strands and two alpha-helices, forming an alpha-beta-alpha sandwich. The conserved Nudix box signature motif, which contains the essential catalytic residues, is located at the first alpha-helix and the beta-strand and loop preceding it. The unusually short connections between secondary-structural elements, together with the dimer form of the structure, are likely to contribute to the thermostability of the P. aerophilum Nudix protein.

  7. Propagating structure of alzheimer's {beta}-amyloid is parallel {beta}-sheet with residues in exact register.

    SciTech Connect

    Benzinger, T. L. S.; Gregory, D. M.; Burkoth, T. S.; Miller-Auer, H.; Lynn, D. G.; Botto, R. E.; Meredith, S. C.; Chemistry; Univ. of Chicago

    1998-11-10

    The pathognomonic plaques of Alzheimer's disease are composed primarily of the 39- to 43-aa {beta}-amyloid (A{beta}) peptide. Crosslinking of A{beta} peptides by tissue transglutaminase (tTg) indicates that Gln15 of one peptide is proximate to Lys16 of another in aggregated A{beta}. Here we report how the fibril structure is resolved by mapping interstrand distances in this core region of the A{beta} peptide chain with solid-state NMR. Isotopic substitution provides the source points for measuring distances in aggregated A{beta}. Peptides containing a single carbonyl 13C label at Gln15, Lys16, Leu17, or Val18 were synthesized and evaluated by NMR dipolar recoupling methods for the measurement of interpeptide distances to a resolution of 0.2 Angstrom. Analysis of these data establish that this central core of A{beta} consists of a parallel {beta}-sheet structure in which identical residues on adjacent chains are aligned directly, i.e., in register. Our data, in conjunction with existing structural data, establish that the A{beta} fibril is a hydrogen-bonded, parallel {beta}-sheet defining the long axis of the A{beta} fibril propagation.

  8. Amyloids of shuffled prion domains that form prions have a parallel in-register beta-sheet structure.

    PubMed

    Shewmaker, Frank; Ross, Eric D; Tycko, Robert; Wickner, Reed B

    2008-04-01

    The [URE3] and [PSI (+)] prions of Saccharomyces cerevisiae are self-propagating amyloid forms of Ure2p and Sup35p, respectively. The Q/N-rich N-terminal domains of each protein are necessary and sufficient for the prion properties of these proteins, forming in each case their amyloid cores. Surprisingly, shuffling either prion domain, leaving amino acid content unchanged, does not abrogate the ability of the proteins to become prions. The discovery that the amino acid composition of a polypeptide, not the specific sequence order, determines prion capability seems contrary to the standard folding paradigm that amino acid sequence determines protein fold. The shuffleability of a prion domain further suggests that the beta-sheet structure is of the parallel in-register type, and indeed, the normal Ure2 and Sup35 prion domains have such a structure. We demonstrate that two shuffled Ure2 prion domains capable of being prions form parallel in-register beta-sheet structures, and our data indicate the same conclusion for a single shuffled Sup35 prion domain. This result confirms our inference that shuffleability indicates parallel in-register structure.

  9. A Genetic-Algorithm-Based Explicit Description of Object Contour and its Ability to Facilitate Recognition.

    PubMed

    Wei, Hui; Tang, Xue-Song

    2015-11-01

    Shape representation is an extremely important and longstanding problem in the field of pattern recognition. Closed contour, which refers to shape contour, plays a crucial role in the comparison of shapes. Because shape contour is the most stable, distinguishable, and invariable feature of an object, it is useful to incorporate it into the recognition process. This paper proposes a method based on genetic algorithms. The proposed method can be used to identify the most common contour fragments, which can be used to represent the contours of a shape category. The common fragments clarify the particular logics included in the contours. This paper shows that the explicit representation of the shape contour contributes significantly to shape representation and object recognition.

  10. Multi-layer Parallel Beta-Sheet Structure of Amyloid Beta peptide (1-40) aggregate observed by discrete molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Peng, Shouyong; Urbanc, Brigita; Ding, Feng; Cruz, Luis; Buldyrev, Sergey; Dokholyan, Nikolay; Stanley, H. E.

    2003-03-01

    New evidence shows that oligomeric forms of Amyloid-Beta are potent neurotoxins that play a major role in neurodegeneration of Alzheimer's disease. Detailed knowledge of the structure and assembly dynamics of Amyloid-Beta is important for the development of new therapeutic strategies. Here we apply a two-atom model with Go interactions to model aggregation of Amyloid-Beta (1-40) peptides using the discrete molecular dynamics simulation. At temperatures above the transition temperature from an alpha-helical to random coil, we obtain two types of parallel beta-sheet structures, (a) a helical beta-sheet structure at a lower temperature and (b) a parallel beta-sheet structure at a higher temperature, both with inter-sheet distance of 10 A and with free edges which possibly enable further fibrillar elongation.

  11. Origin of life. Primordial genetics: Information transfer in a pre-RNA world based on self-replicating beta-sheet amyloid conformers.

    PubMed

    Maury, Carl Peter J

    2015-10-01

    The question of the origin of life on Earth can largely be reduced to the question of what was the first molecular replicator system that was able to replicate and evolve under the presumably very harsh conditions on the early Earth. It is unlikely that a functional RNA could have existed under such conditions and it is generally assumed that some other kind of information system preceded the RNA world. Here, I present an informational molecular system that is stable, self-replicative, environmentally responsive, and evolvable under conditions characterized by high temperatures, ultraviolet and cosmic radiation. This postulated pregenetic system is based on the amyloid fold, a functionally unique polypeptide fold characterized by a cross beta-sheet structure in which the beta strands are arranged perpendicular to the fiber axis. Beside an extraordinary structural robustness, the amyloid fold possesses a unique ability to transmit information by a three-dimensional templating mechanism. In amyloidogenesis short peptide monomers are added one by one to the growing end of the fiber. From the same monomeric subunits several structural variants of amyloid may be formed. Then, in a self-replicative mode, a specific amyloid conformer can act as a template and confer its spatially encoded information to daughter molecular entities in a repetitive way. In this process, the specific conformational information, the spatially changed organization, is transmitted; the coding element is the steric zipper structure, and recognition occurs by amino acid side chain complementarity. The amyloid information system fulfills several basic requirements of a primordial evolvable replicator system: (i) it is stable under the presumed primitive Earth conditions, (ii) the monomeric building blocks of the informational polymer can be formed from available prebiotic compounds, (iii) the system is self-assembling and self-replicative and (iv) it is adaptive to changes in the environment and

  12. Attentional cueing by cross-modal congruency produces both facilitation and inhibition on short-term visual recognition.

    PubMed

    Makovac, Elena; Kwok, Sze Chai; Gerbino, Walter

    2014-10-01

    The attentional modulation of performance in a memory task, comparable to the one obtained in a perceptual task, is at the focus of contemporary research. We hypothesized that a biphasic effect (namely, facilitation followed by inhibition) can be obtained in visual working memory when attention is cued towards one item of the memorandum and participants must recognize a delayed probe as being identical to any item of the memorandum. In every trial, a delayed spiky/curvy probe appeared centrally, to be matched with the same-category shape maintained in visual working memory which could be either physically identical (positive trials) or only categorically similar (negative trials). To orient the participant's attention towards a selected portion of a two-item memorandum, a (tzk/wow) sound was played simultaneously with two lateral visual shapes (one spiky and one curved). Our results indicate that an exogenous attentional shift during perception of the memorandum, induced by a congruent audio-visual pairing, first facilitates and then inhibits the recognition of a cued item (but not of a non-cued item) stored in visual working memory. A coherent pattern of individual differences emerged, indicating that the amount of early facilitation in congruent-sound trials was negatively correlated with recognition sensitivity in no-sound trials (suggesting that the inverse effectiveness rule may also apply to memory) and positively correlated with later inhibition, as well as with the self-reported susceptibility to memory failures. PMID:25126752

  13. Invader probes: Harnessing the energy of intercalation to facilitate recognition of chromosomal DNA for diagnostic applications†

    PubMed Central

    Guenther, Dale C.; Anderson, Grace H.; Karmakar, Saswata; Anderson, Brooke A.; Didion, Bradley A.; Guo, Wei; Verstegen, John P.; Hrdlicka, Patrick J.

    2015-01-01

    Development of probes capable of recognizing specific regions of chromosomal DNA has been a long-standing goal for chemical biologists. Current strategies such as PNA, triplex-forming oligonucleotides, and polyamides are subject to target choice limitations and/or necessitate non-physiological conditions, leaving a need for alternative approaches. Toward this end, we have recently introduced double-stranded oligonucleotide probes that are energetically activated for DNA recognition through modification with +1 interstrand zippers of intercalator-functionalized nucleotide monomers. Here, probes with different chemistries and architectures – varying in the position, number, and distance between the intercalator zippers – are studied with respect to hybridization energetics and DNA-targeting properties. Experiments with model DNA targets demonstrate that optimized probes enable efficient (C50 < 1 μM), fast (t50 < 3h), kinetically stable (> 24h), and single nucleotide specific recognition of DNA targets at physiologically relevant ionic strengths. Optimized probes were used in non-denaturing fluorescence in situ hybridization experiments for detection of gender-specific mixed-sequence chromosomal DNA target regions. These probes present themselves as a promising strategy for recognition of chromosomal DNA, which will enable development of new tools for applications in molecular biology, genomic engineering and nanotechnology. PMID:26240741

  14. Multinuclear NMR studies of the flavodoxin from Anabaena 7120:. beta. -sheet structure and the flavin mononucleotide binding site

    SciTech Connect

    Stockman, B.J.

    1989-01-01

    A concerted approach to primary {sup 1}H, {sup 13}C, and {sup 15}N nuclear magnetic resonance assignments in proteins was developed. The method requires enrichment of the protein with {sup 13}C and {sup 15}N. The technique relies on the comparison of data sets from NMR experiments that correlate various nuclei: {sup 13}C({sup 13}C) double quantum correlations, {sup 1}H({sup 13}C) and {sup 1}H({sup 15}N) single bond correlations, and {sup 1}H({sup 13}C) and {sup 1}H({sup 15}N) multiple bond correlations. Comparison of data sets increases the number of resonances that can be assigned and improves assignment confidence. By combined use of these and conventional NMR techniques, sequential assignments were made for the {beta}-sheet and flavin mononucleotide (FMN) binding site residues in flavodoxin from Anabaena 7120. The {beta}-sheet structure was found to be similar to that seen in the crystal structure of Anacystis nidulans flavodoxin. In the FMN binding site, a total of 69 NOEs were identified: eight between protons of FMN, 36 between protons of binding site residues, and 25 between protons of FMN and protein. These constraints were used to determine the localized solution structure of the flavin binding site. The electronic environment and conformation of the protein-bound isoalloxazine ring were investigated by determining chemical shifts and coupling constants for the ring atoms. The carbonyl edge of the flavin ring was found to be slightly polarized by hydrogen bonding to the protein. The xylene ring was found to be nonplanar. The C{sup 6}-N{sup 5} region of the flavin appears to be solvent accessible.

  15. Metallopolymer-peptide conjugates: synthesis and self-assembly of polyferrocenylsilane graft and block copolymers containing a beta-sheet forming Gly-Ala-Gly-Ala tetrapeptide segment.

    PubMed

    Vandermeulen, Guido W M; Kim, Kyoung Taek; Wang, Zhuo; Manners, Ian

    2006-04-01

    We describe the synthesis and self-assembly of two beta-sheet forming metallopolymer-peptide conjugates. The ability of the oligotetrapeptide sequence Gly-Ala-Gly-Ala (GAGA) to form antiparallel beta-sheets was retained in PFS-b-AGAG (PFS = polyferrocenylsilane) and PFS-g-AGAG conjugates with block and graft architectures, respectively. In the solid state, DSC experiments suggest a phase separation between the peptide and PFS domains. In toluene, PFS-b-AGAG interestingly forms a fibrous network which consists of a core containing the self-assembled antiparallel beta-sheet peptide and a corona of organometallic PFS. The self-assembly of the peptide into antiparallel beta-sheets is the driving force for the fiber formation, whereas PFS prevents uncontrolled lateral aggregation of the fibers. The use of an oligopeptide to self-assemble an otherwise random coiled organometallic polymer may be a useful strategy to enhance nanostructure formation. In the cases described here, the conjugates may be used to create nanopatterned ceramics, and the redox properties of the resulting supramolecular aggregates are of significant interest. PMID:16602714

  16. Male mate recognition via cuticular hydrocarbons facilitates sexual isolation between sympatric leaf beetle sister species.

    PubMed

    Zhang, Bin; Xue, Huai-Jun; Song, Ke-Qing; Liu, Jie; Li, Wen-Zhu; Nie, Rui-E; Yang, Xing-Ke

    2014-11-01

    Chemical signals in insects have been documented to play an important role in mate recognition, and divergence in chemical signals can often cause sexual isolation between closely related species or populations within species. We investigated the role of cuticular hydrocarbons (CHCs), short distance chemical signals, in male mate recognition between the two sympatric elm leaf beetles, Pyrrhalta maculicollis and Pyrrhaltaaenescens. Mating experiments demonstrated that strong sexual isolation between the two species was driven by CHCs divergence. Males preferred to mate with conspecific females with intact conspecific CHCs or conspecific CHCs reapplied after removal. Males also preferred heterospecific females that were treated with conspecific CHCs. Chemical analysis showed that the CHC profiles differ significantly between species. In P. maculicollis dimethyl-branched alkanes between C29 and C35 account for the majority of the saturated alkanes while the CHC profile of P. aenescens mostly consisted of monomethyl-branched alkanes between C22 and C29. Additionally, some compounds, such as 12,18-diMeC32, 12,18-diMeC34, are unique to P. maculicollis.

  17. Substrate recognition by gelatinase A: the C-terminal domain facilitates surface diffusion.

    PubMed Central

    Collier, I E; Saffarian, S; Marmer, B L; Elson, E L; Goldberg, G

    2001-01-01

    An investigation of gelatinase A binding to gelatin produced results that are inconsistent with a traditional bimolecular Michaelis-Menten formalism but are effectively accounted for by a power law characteristic of fractal kinetics. The main reason for this inconsistency is that the bulk of the gelatinase A binding depends on its ability to diffuse laterally on the gelatin surface. Most interestingly, we show that the anomalous lateral diffusion and, consequently, the binding to gelatin is greatly facilitated by the C-terminal hemopexin-like domain of the enzyme whereas the specificity of binding resides with the fibronectin-like gelatin-binding domain. PMID:11566806

  18. Activation of p53 Facilitates the Target Search in DNA by Enhancing the Target Recognition Probability.

    PubMed

    Itoh, Yuji; Murata, Agato; Sakamoto, Seiji; Nanatani, Kei; Wada, Takehiko; Takahashi, Satoshi; Kamagata, Kiyoto

    2016-07-17

    Tumor suppressor p53 binds to the target in a genome and regulates the expression of downstream genes. p53 searches for the target by combining three-dimensional diffusion and one-dimensional sliding along the DNA. To examine the regulation mechanism of the target binding, we constructed the pseudo-wild type (pseudo-WT), activated (S392E), and inactive (R248Q) mutants of p53 and observed their target binding in long DNA using single-molecule fluorescence imaging. The pseudo-WT sliding along the DNA showed many pass events over the target and possessed target recognition probability (TRP) of 7±2%. The TRP increased to 18±2% for the activated mutant but decreased to 0% for the inactive mutant. Furthermore, the fraction of the target binding by the one-dimensional sliding among the total binding events increased from 63±9% for the pseudo-WT to 87±2% for the activated mutant. Control of TRP upon activation, as demonstrated here for p53, might be a general activation mechanism of transcription factors.

  19. Sing that tune: infants' perception of melody and lyrics and the facilitation of phonetic recognition in songs.

    PubMed

    Lebedeva, Gina C; Kuhl, Patricia K

    2010-12-01

    To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (experiment 1), but did not detect the identical pitch change with variegated syllables (experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (experiment 2) than the identical syllable change in a spoken sequence (experiment 1). These results suggest that by 11 months, infants cannot "ignore" phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy. PMID:20472295

  20. Sing that tune: infants' perception of melody and lyrics and the facilitation of phonetic recognition in songs.

    PubMed

    Lebedeva, Gina C; Kuhl, Patricia K

    2010-12-01

    To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (experiment 1), but did not detect the identical pitch change with variegated syllables (experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (experiment 2) than the identical syllable change in a spoken sequence (experiment 1). These results suggest that by 11 months, infants cannot "ignore" phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy.

  1. Sing that Tune: Infants’ Perception of Melody and Lyrics and the Facilitation of Phonetic Recognition in Songs

    PubMed Central

    Lebedeva, Gina C.; Kuhl, Patricia K.

    2010-01-01

    To better understand how infants process complex auditory input, this study investigated whether 11-month-old infants perceive the pitch (melodic) or the phonetic (lyric) components within songs as more salient, and whether melody facilitates phonetic recognition. Using a preferential looking paradigm, uni-dimensional and multi-dimensional songs were tested; either the pitch or syllable order of the stimuli varied. As a group, infants detected a change in pitch order in a 4-note sequence when the syllables were redundant (Experiment 1), but did not detect the identical pitch change with variegated syllables (Experiment 2). Infants were better able to detect a change in syllable order in a sung sequence (Experiment 2) than the identical syllable change in a spoken sequence (Experiment 1). These results suggest that by 11 months, infants cannot “ignore” phonetic information in the context of perceptually salient pitch variation. Moreover, the increased phonetic recognition in song contexts mirrors findings that demonstrate advantages of infant-directed speech. Findings are discussed in terms of how stimulus complexity interacts with the perception of sung speech in infancy. PMID:20472295

  2. Conversion of non-fibrillar {beta}-sheet oligomers into amyloid fibrils in Alzheimer's disease amyloid peptide aggregation

    SciTech Connect

    Benseny-Cases, Nuria; Cocera, Mercedes; Cladera, Josep

    2007-10-05

    A{beta}(1-40) is one of the main components of the fibrils found in amyloid plaques, a hallmark of brains affected by Alzheimer's disease. It is known that prior to the formation of amyloid fibrils in which the peptide adopts a well-ordered intermolecular {beta}-sheet structure, peptide monomers associate forming low and high molecular weight oligomers. These oligomers have been previously described in electron microscopy, AFM, and exclusion chromatography studies. Their specific secondary structures however, have not yet been well established. A major problem when comparing aggregation and secondary structure determinations in concentration-dependent processes such as amyloid aggregation is the different concentration range required in each type of experiment. In the present study we used the dye Thioflavin T (ThT), Fourier-transform infrared spectroscopy, and electron microscopy in order to structurally characterize the different aggregated species which form during the A{beta}(1-40) fibril formation process. A unique sample containing 90 {mu}M peptide was used. The results show that oligomeric species which form during the lag phase of the aggregation kinetics are a mixture of unordered, helical, and intermolecular non-fibrillar {beta}-structures. The number of oligomers and the amount of non-fibrillar {beta}-structures grows throughout the lag phase and during the elongation phase these non-fibrillar {beta}-structures are transformed into fibrillar (amyloid) {beta}-structures, formed by association of high molecular weight intermediates.

  3. The crystal structure of human glycosylation-inhibiting factor is a trimeric barrel with three 6-stranded beta-sheets.

    PubMed Central

    Kato, Y; Muto, T; Tomura, T; Tsumura, H; Watarai, H; Mikayama, T; Ishizaka, K; Kuroki, R

    1996-01-01

    Glycosylation-inhibiting factor (GIF) is a cytokine that is involved in the regulation of IgE synthesis. The crystal structure of recombinant human GIF was determined by the multiple isomorphous replacement method. The structure was refined to an R factor of 0.168 at 1.9 angstrom resolution. The overall structure is seen to consist of three interconnected subunits forming a barrel with three 6-stranded beta-sheets on the inside and six alpha-helices on the outside. There is a 5-angstrom-diameter "hole" through the middle of the barrel. The barrel structure of GIF in part resembles other "trefoil" cytokines such as interleukin 1 and fibroblast growth factor. Each subunit has a new class of alpha + beta sandwich structure consisting of two beta-alpha-beta motifs. These beta-alpha-beta motifs are related by a pseudo-twofold axis and resemble both interleukin 8 and the peptide binding domain of major histocompatibility complex protein, although the topology of the polypeptide chain is quite different. Images Fig. 1 Fig. 3 PMID:8610159

  4. The solubilization of model Alzheimer tangles: reversing the beta-sheet conformation induced by aluminum with silicates.

    PubMed Central

    Fasman, G D; Moore, C D

    1994-01-01

    Neurofibrillary tangles are one of two lesions found in the brain of Alzheimer disease victims. With synthetic peptide fragments of human neurofilament NF-M17 (Glu-Glu-Lys-Gly-Lys-Ser-Pro- Val-Pro-Lys-Ser-Pro-Val-Glu-Glu-Lys-Gly, phosphorylated and unphosphorylated), CD studies were done to examine the effect of sodium orthosilicate on the conformational state produced by Al3+ on fragments of neuronal proteins. Previous studies had shown a conformational transition from alpha-helix and random to beta-pleated sheet upon addition of Al3+ to both phosphorylated and unphosphorylated peptides. If sufficient quantities of Al3+ are added, the peptide precipitates from solution. The ability to reverse or slow the progression of aggregation was examined. Al3+ binding was reversed with 1-2 molar equivalents of sodium orthosilicate (with respect to Al3+), altering the conformation from beta-sheet to random coil and resulting in a CD spectrum similar to that of the initial peptide. The tight binding of the SiO4(4-) with the Al3+ provides the mechanism for this transition. These results provide additional information toward understanding the role of aluminum in the Alzheimer diseased brain and suggest the investigation of the possible use of silicates as a therapeutic agent. PMID:7972040

  5. The crystal structures of [Met5]enkephalin and a third form of [Leu5]enkephalin: observations of a novel pleated beta-sheet.

    PubMed Central

    Griffin, J F; Langs, D A; Smith, G D; Blundell, T L; Tickle, I J; Bedarkar, S

    1986-01-01

    The structures of [Met5]enkephalin (Tyr-Gly-Gly-Phe-Met) and [Leu5]enkephalin (Tyr-Gly-Gly-Phe-Leu) have been determined from single crystal x-ray diffraction data and refined to residuals of 0.100 and 0.092, respectively. The [Met5]enkephalin structure consists of dimers forming antiparallel beta-sheets extending in the monoclinic ac plane with 10.6 water molecules per dimer. The two molecules, related by pseudo two-fold axes, have similar backbone conformations and similar tyrosine and phenylalanine side-chain conformations. Both methionine residues are disordered and the disorder is different in the two independent molecules. Additional hydrogen bonds connect adjacent dimers to form infinite sheets normal to the b axis. The water molecules are found mainly in the interstices between the sheets. [Leu5]Enkephalin crystallizes as a monohydrate that is isomorphous with the [Met5]enkephalin structure with respect to the beta-sheet but different with respect to the tyrosine and phenylalanine side-chain conformations and water content. The peptide chains in both structures are fully extended and more nearly planar than pleated. The planes of the peptide chains in the dimers form an angle of 143.3 degrees with one another in [Met5]enkephalin and 156.0 degrees in [Leu5]enkephalin. This produces a zigzag pattern or pleat in the beta-sheets perpendicular to the direction of the peptide chains and, therefore, perpendicular to the normal beta-sheet pleat. The average repeat distance between Ni and Ni+2 in the peptide chains of both structures is 7.10 A, versus an ideal value of 6.68 A. PMID:3458181

  6. Aluminium and iron, but neither copper nor zinc, are key to the precipitation of beta-sheets of Abeta_{42} in senile plaque cores in Alzheimer's disease.

    PubMed

    Exley, Christopher

    2006-11-01

    A number of metals including Fe(II)/Fe(III), Al(III), Zn(II) and Cu(II) are found co-localised with beta-sheets of Abeta_{42} in senile plaque cores in AD brain. We know neither why nor how the co-localisation takes place or, indeed, if it is entirely aberrant or partly protective. There are data from in vitro studies which may begin to explain some of these unanswered questions and in considering these I have summised that Al(III) and Fe(III)/Fe(II) are directly involved in the precipitation of beta-sheets of Abeta_{42} in senile plaque cores whereas the presence of Cu(II) and Zn(II) is adventitious. The co-deposition of Al(III), Fe(III) and beta-sheets of Abeta_{42} could act as a source of reactive oxygen species and begin to explain some of the oxidative damage found in the immediate vicinity of senile plaques. Whether such metal-Abeta_{42} synergisms are an integral part of the aetiology of AD remains to be confirmed.

  7. Effect of secondary structure on the potential of mean force for poly-L-lysine in the alpha-Helix and beta-sheet conformations

    SciTech Connect

    Grigsby, J.J.; Blanch, H.W.; Prausnitz, J.M.

    2001-10-30

    Because poly-L-lysine (PLL) can exist in the {alpha}-helix or {beta}-sheet conformation depending on solution preparation and solution conditions, PLL is a suitable candidate to probe the dependence of protein interactions on secondary structure. The osmotic second virial coefficient and weight-average molecular weight are reported from low-angle laser-light scattering measurements for PLL as a function of NaCl concentration, pH, and {alpha}-helix or {beta}-sheet content. Interactions between PLL molecules become more attractive as salt concentration increases due to screening of PLL charge by salt ions and at low salt concentration become more attractive as pH increases due to decreased net charge on PLL. The experimental results show that interactions are stronger for the {beta}-sheet conformation than for the {alpha}-helix conformation. A spherically-symmetric model for the potential of mean force is used to account for specific interactions not described by DLVO theory and to show how differences in secondary structure affect PLL interactions.

  8. Facilitated receptor-recognition and enhanced bioactivity of bone morphogenetic protein-2 on magnesium-substituted hydroxyapatite surface

    NASA Astrophysics Data System (ADS)

    Huang, Baolin; Yuan, Yuan; Li, Tong; Ding, Sai; Zhang, Wenjing; Gu, Yuantong; Liu, Changsheng

    2016-04-01

    Biomaterial surface functionalized with bone morphogenetic protein-2 (BMP-2) is a promising approach to fabricating successful orthopedic implants/scaffolds. However, the bioactivity of BMP-2 on material surfaces is still far from satisfactory and the mechanism of related protein-surface interaction remains elusive. Based on the most widely used bone-implants/scaffolds material, hydroxyapatite (HAP), we developed a matrix of magnesium-substituted HAP (Mg-HAP, 2.2 at% substitution) to address these issues. Further, we investigated the adsorption dynamics, BMPRs-recruitment, and bioactivity of recombinant human BMP-2 (rhBMP-2) on the HAP and Mg-HAP surfaces. To elucidate the mechanism, molecular dynamic simulations were performed to calculate the preferred orientations, conformation changes, and cysteine-knot stabilities of adsorbed BMP-2 molecules. The results showed that rhBMP-2 on the Mg-HAP surface exhibited greater bioactivity, evidenced by more facilitated BMPRs-recognition and higher ALP activity than on the HAP surface. Moreover, molecular simulations indicated that BMP-2 favoured distinct side-on orientations on the HAP and Mg-HAP surfaces. Intriguingly, BMP-2 on the Mg-HAP surface largely preserved the active protein structure evidenced by more stable cysteine-knots than on the HAP surface. These findings explicitly clarify the mechanism of BMP-2-HAP/Mg-HAP interactions and highlight the promising application of Mg-HAP/BMP-2 matrixes in bone regeneration implants/scaffolds.

  9. Facilitated receptor-recognition and enhanced bioactivity of bone morphogenetic protein-2 on magnesium-substituted hydroxyapatite surface

    PubMed Central

    Huang, Baolin; Yuan, Yuan; Li, Tong; Ding, Sai; Zhang, Wenjing; Gu, Yuantong; Liu, Changsheng

    2016-01-01

    Biomaterial surface functionalized with bone morphogenetic protein-2 (BMP-2) is a promising approach to fabricating successful orthopedic implants/scaffolds. However, the bioactivity of BMP-2 on material surfaces is still far from satisfactory and the mechanism of related protein-surface interaction remains elusive. Based on the most widely used bone-implants/scaffolds material, hydroxyapatite (HAP), we developed a matrix of magnesium-substituted HAP (Mg-HAP, 2.2 at% substitution) to address these issues. Further, we investigated the adsorption dynamics, BMPRs-recruitment, and bioactivity of recombinant human BMP-2 (rhBMP-2) on the HAP and Mg-HAP surfaces. To elucidate the mechanism, molecular dynamic simulations were performed to calculate the preferred orientations, conformation changes, and cysteine-knot stabilities of adsorbed BMP-2 molecules. The results showed that rhBMP-2 on the Mg-HAP surface exhibited greater bioactivity, evidenced by more facilitated BMPRs-recognition and higher ALP activity than on the HAP surface. Moreover, molecular simulations indicated that BMP-2 favoured distinct side-on orientations on the HAP and Mg-HAP surfaces. Intriguingly, BMP-2 on the Mg-HAP surface largely preserved the active protein structure evidenced by more stable cysteine-knots than on the HAP surface. These findings explicitly clarify the mechanism of BMP-2-HAP/Mg-HAP interactions and highlight the promising application of Mg-HAP/BMP-2 matrixes in bone regeneration implants/scaffolds. PMID:27075233

  10. A cholesterol recognition amino acid consensus domain in GP64 fusion protein facilitates anchoring of baculovirus to mammalian cells.

    PubMed

    Luz-Madrigal, Agustin; Asanov, Alexander; Camacho-Zarco, Aldo R; Sampieri, Alicia; Vaca, Luis

    2013-11-01

    Baculoviridae is a large family of double-stranded DNA viruses that selectively infect insects. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the best-studied baculovirus from the family. Many studies over the last several years have shown that AcMNPV can enter a wide variety of mammalian cells and deliver genetic material for foreign gene expression. While most animal viruses studied so far have developed sophisticated mechanisms to selectively infect specific cells and tissues in an organism, AcMNPV can penetrate and deliver foreign genes into most cells studied to this date. The details about the mechanisms of internalization have been partially described. In the present study, we have identified a cholesterol recognition amino acid consensus (CRAC) domain present in the AcMNPV envelope fusion protein GP64. We demonstrated the association of a CRAC domain with cholesterol, which is important to facilitate the anchoring of the virus at the mammalian cell membrane. Furthermore, this initial anchoring favors AcMNPV endocytosis via a dynamin- and clathrin-dependent mechanism. Under these conditions, efficient baculovirus-driven gene expression is obtained. In contrast, when cholesterol is reduced from the plasma membrane, AcMNPV enters the cell via a dynamin- and clathrin-independent mechanism. The result of using this alternative internalization pathway is a reduced level of baculovirus-driven gene expression. This study is the first to document the importance of a novel CRAC domain in GP64 and its role in modulating gene delivery in AcMNPV.

  11. A Cholesterol Recognition Amino Acid Consensus Domain in GP64 Fusion Protein Facilitates Anchoring of Baculovirus to Mammalian Cells

    PubMed Central

    Luz-Madrigal, Agustin; Asanov, Alexander; Camacho-Zarco, Aldo R.; Sampieri, Alicia

    2013-01-01

    Baculoviridae is a large family of double-stranded DNA viruses that selectively infect insects. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the best-studied baculovirus from the family. Many studies over the last several years have shown that AcMNPV can enter a wide variety of mammalian cells and deliver genetic material for foreign gene expression. While most animal viruses studied so far have developed sophisticated mechanisms to selectively infect specific cells and tissues in an organism, AcMNPV can penetrate and deliver foreign genes into most cells studied to this date. The details about the mechanisms of internalization have been partially described. In the present study, we have identified a cholesterol recognition amino acid consensus (CRAC) domain present in the AcMNPV envelope fusion protein GP64. We demonstrated the association of a CRAC domain with cholesterol, which is important to facilitate the anchoring of the virus at the mammalian cell membrane. Furthermore, this initial anchoring favors AcMNPV endocytosis via a dynamin- and clathrin-dependent mechanism. Under these conditions, efficient baculovirus-driven gene expression is obtained. In contrast, when cholesterol is reduced from the plasma membrane, AcMNPV enters the cell via a dynamin- and clathrin-independent mechanism. The result of using this alternative internalization pathway is a reduced level of baculovirus-driven gene expression. This study is the first to document the importance of a novel CRAC domain in GP64 and its role in modulating gene delivery in AcMNPV. PMID:23986592

  12. 2D 1H and 3D 1H-15N NMR of zinc-rubredoxins: contributions of the beta-sheet to thermostability.

    PubMed Central

    Richie, K. A.; Teng, Q.; Elkin, C. J.; Kurtz, D. M.

    1996-01-01

    Based on 2D 1H-1H and 2D and 3D 1H-15N NMR spectroscopies, complete 1H NMR assignments are reported for zinc-containing Clostridium pasteurianum rubredoxin (Cp ZnRd). Complete 1H NMR assignments are also reported for a mutated Cp ZnRd, in which residues near the N-terminus, namely, Met 1, Lys 2, and Pro 15, have been changed to their counterparts, (-), Ala and Glu, respectively, in rubredoxin from the hyperthermophilic archaeon, Pyrococcus furiosus (Pf Rd). The secondary structure of both wild-type and mutated Cp ZnRds, as determined by NMR methods, is essentially the same. However, the NMR data indicate an extension of the three-stranded beta-sheet in the mutated Cp ZnRd to include the N-terminal Ala residue and Glu 15, as occurs in Pf Rd. The mutated Cp Rd also shows more intense NOE cross peaks, indicating stronger interactions between the strands of the beta-sheet and, in fact, throughout the mutated Rd. However, these stronger interactions do not lead to any significant increase in thermostability, and both the mutated and wild-type Cp Rds are much less thermostable than Pf Rd. These correlations strongly suggest that, contrary to a previous proposal [Blake PR et al., 1992, Protein Sci 1:1508-1521], the thermostabilization mechanism of Pf Rd is not dominated by a unique set of hydrogen bonds or electrostatic interactions involving the N-terminal strand of the beta-sheet. The NMR results also suggest that an overall tighter protein structure does not necessarily lead to increased thermostability. PMID:8732760

  13. Crystal structure and a twisted beta-sheet conformation of the tripeptide L-leucyl-L-leucyl-L-leucine monohydrate trimethanol solvate: conformation analysis of tripeptides.

    PubMed

    Go, K; Parthasarathy, R

    1995-11-01

    In order to test the helical preference of short oligo-L-leucines, we crystallized the tripeptide L-leucyl-L-leucyl-L-leucine (LLL) and carried out x-ray diffraction studies of it (L-leucyl-L-leucyl-Lleucine)2. 3CH3OH. H2O, (C39H84N6O12), crystallized in the monoclinic system, space group P2(1), cell parameters: a = 12.031(2), b = 15.578(3), c = 14.087(2) A, alpha = 90 degrees, beta = 97.29(1) degrees, gamma = 90 degrees, V = 2618.6 A3, MW = 829.1, Dc = 1.051 g cm-3, R index of 0.057 for 4213 reflections (lambda CuK alpha = 1.5418 A) > 2 sigma. LLL takes up the beta-sheet rather than a helical conformation in the crystalline state. The three methanol molecules and the water molecule that constitute the solvent of crystallization form a network of hydrogen bonds to the LLL molecules and to one another. It is rather remarkable that though A and L have stronger helical preferences than G, neither AAA nor LLL form the crystalline helix but GAL does, indicating that the helical preferences depend on the sequence context. The residue L2 in molecule A and the residues L1 and L3 of molecule B do not show the preferred conformation for forming helices. Further, very remarkably, LLL exhibits a unique supersecondary feature of the protein folding topology, namely the twisted beta-sheet, whereas most short peptides show only the classical beta-sheet conformation.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. PB1-F2 influenza A virus protein adopts a beta-sheet conformation and forms amyloid fibers in membrane environments.

    PubMed

    Chevalier, Christophe; Al Bazzal, Ali; Vidic, Jasmina; Février, Vincent; Bourdieu, Christiane; Bouguyon, Edwige; Le Goffic, Ronan; Vautherot, Jean-François; Bernard, Julie; Moudjou, Mohammed; Noinville, Sylvie; Chich, Jean-François; Da Costa, Bruno; Rezaei, Human; Delmas, Bernard

    2010-04-23

    The influenza A virus PB1-F2 protein, encoded by an alternative reading frame in the PB1 polymerase gene, displays a high sequence polymorphism and is reported to contribute to viral pathogenesis in a sequence-specific manner. To gain insights into the functions of PB1-F2, the molecular structure of several PB1-F2 variants produced in Escherichia coli was investigated in different environments. Circular dichroism spectroscopy shows that all variants have a random coil secondary structure in aqueous solution. When incubated in trifluoroethanol polar solvent, all PB1-F2 variants adopt an alpha-helix-rich structure, whereas incubated in acetonitrile, a solvent of medium polarity mimicking the membrane environment, they display beta-sheet secondary structures. Incubated with asolectin liposomes and SDS micelles, PB1-F2 variants also acquire a beta-sheet structure. Dynamic light scattering revealed that the presence of beta-sheets is correlated with an oligomerization/aggregation of PB1-F2. Electron microscopy showed that PB1-F2 forms amorphous aggregates in acetonitrile. In contrast, at low concentrations of SDS, PB1-F2 variants exhibited various abilities to form fibers that were evidenced as amyloid fibers in a thioflavin T assay. Using a recombinant virus and its PB1-F2 knock-out mutant, we show that PB1-F2 also forms amyloid structures in infected cells. Functional membrane permeabilization assays revealed that the PB1-F2 variants can perforate membranes at nanomolar concentrations but with activities found to be sequence-dependent and not obviously correlated with their differential ability to form amyloid fibers. All of these observations suggest that PB1-F2 could be involved in physiological processes through different pathways, permeabilization of cellular membranes, and amyloid fiber formation.

  15. Forensic facial approximation assessment: can application of different average facial tissue depth data facilitate recognition and establish acceptable level of resemblance?

    PubMed

    Herrera, Lara Maria; Strapasson, Raíssa Ananda Paim; da Silva, Jorge Vicente Lopes; Melani, Rodolfo Francisco Haltenhoff

    2016-09-01

    Facial soft tissue thicknesses (FSTT) are important guidelines for modeling faces from skull. Amid so many FSTT data, Forensic artists have to make a subjective choice of a dataset that best meets their needs. This study investigated the performance of four FSTT datasets in the recognition and resemblance of Brazilian living individuals and the performance of assessors in recognizing people, according to sex and knowledge on Human Anatomy and Forensic Dentistry. Sixteen manual facial approximations (FAs) were constructed using three-dimensional (3D) prototypes of skulls (targets). The American method was chosen for the construction of the faces. One hundred and twenty participants evaluated all FAs by means of recognition and resemblance tests. This study showed higher proportions of recognition by FAs conducted with FSTT data from cadavers compared with those conducted with medical imaging data. Targets were also considered more similar to FAs conducted with FSTT data from cadavers. Nose and face shape, respectively, were considered the most similar regions to targets. The sex of assessors (male and female) and the knowledge on Human Anatomy and Forensic Dentistry did not play a determinant role to reach greater recognition rates. It was possible to conclude that FSTT data obtained from imaging may not facilitate recognition and establish acceptable level of resemblance. Grouping FSTT data by regions of the face, as proposed in this paper, may contribute to more accurate FAs.

  16. The three-dimensional structural surface of two beta-sheet scorpion toxins mimics that of an alpha-helical dihydropyridine receptor segment.

    PubMed Central

    Green, Daniel; Pace, Suzi; Curtis, Suzanne M; Sakowska, Magdalena; Lamb, Graham D; Dulhunty, Angela F; Casarotto, Marco G

    2003-01-01

    An alpha-helical II-III loop segment of the dihydropyridine receptor activates the ryanodine receptor calcium-release channel. We describe a novel manipulation in which this agonist's activity is increased by modifying its surface structure to resemble that of a toxin molecule. In a unique system, native beta-sheet scorpion toxins have been reported to activate skeletal muscle ryanodine receptor calcium channels with high affinity by binding to the same site as the lower-affinity alpha-helical dihydropyridine receptor segment. We increased the alignment of basic residues in the alpha-helical peptide to mimic the spatial orientation of active residues in the scorpion toxin, with a consequent 2-20-fold increase in the activity of the alpha-helical peptide. We hypothesized that, like the native peptide, the modified peptide and the scorpion toxin may bind to a common site. This was supported by (i) similar changes in ryanodine receptor channel gating induced by the native or modified alpha-helical peptide and the beta-sheet toxin, a 10-100-fold reduction in channel closed time, with a < or = 2-fold increase in open dwell time and (ii) a failure of the toxin to further activate channels activated by the peptides. These results suggest that diverse structural scaffolds can present similar conformational surface properties to target common receptor sites. PMID:12429019

  17. The molecular organization of the beta-sheet region in Corneous beta-proteins (beta-keratins) of sauropsids explains its stability and polymerization into filaments.

    PubMed

    Calvaresi, Matteo; Eckhart, Leopold; Alibardi, Lorenzo

    2016-06-01

    The hard corneous material of avian and reptilian scales, claws, beak and feathers is mainly derived from the presence of proteins formerly known as beta-keratins but now termed Corneous beta-proteins of sauropsids to distinguish them from keratins, which are members of the intermediate filament protein family. The modeling of the conserved 34 amino acid residues long central beta-sheet region of Corneous beta-proteins using an ab initio protein folding and structure prediction algorithm indicates that this region is formed by four antiparallel beta-sheets. Molecular dynamic simulations and Molecular Mechanics/Poisson Boltzmann Surface Area (MM-PBSA) analysis showed that the disposition of polar and apolar amino acids within the beta-region gives rise to an amphipathic core whose stability is further increased, especially in an aqueous environment, by the association into a dimer due to apolar interactions and specific amino-acid interactions. The dimers in turn polymerize into a 3nm thick linear beta-filament due to van der Waals and hydrogen-bond interactions. It is suggested that once this nuclear core of anti-parallel sheets evolved in the genome of a reptilian ancestor of the extant reptiles and birds about 300 millions years ago, new properties emerged in the corneous material forming scales, claws, beaks and feathers in these amniotes based on the tendency of these unique corneous proteins to form stable filaments different from keratin intermediate filaments or sterical structures formed by other corneous proteins so far known.

  18. Protein Secondary Structures (alpha-helix and beta-sheet) at a Cellular Levle and Protein Fractions in Relation to Rumen Degradation Behaviours of Protein: A New Approach

    SciTech Connect

    Yu,P.

    2007-01-01

    Studying the secondary structure of proteins leads to an understanding of the components that make up a whole protein, and such an understanding of the structure of the whole protein is often vital to understanding its digestive behaviour and nutritive value in animals. The main protein secondary structures are the {alpha}-helix and {beta}-sheet. The percentage of these two structures in protein secondary structures influences protein nutritive value, quality and digestive behaviour. A high percentage of {beta}-sheet structure may partly cause a low access to gastrointestinal digestive enzymes, which results in a low protein value. The objectives of the present study were to use advanced synchrotron-based Fourier transform IR (S-FTIR) microspectroscopy as a new approach to reveal the molecular chemistry of the protein secondary structures of feed tissues affected by heat-processing within intact tissue at a cellular level, and to quantify protein secondary structures using multicomponent peak modelling Gaussian and Lorentzian methods, in relation to protein digestive behaviours and nutritive value in the rumen, which was determined using the Cornell Net Carbohydrate Protein System. The synchrotron-based molecular chemistry research experiment was performed at the National Synchrotron Light Source at Brookhaven National Laboratory, US Department of Energy. The results showed that, with S-FTIR microspectroscopy, the molecular chemistry, ultrastructural chemical make-up and nutritive characteristics could be revealed at a high ultraspatial resolution ({approx}10 {mu}m). S-FTIR microspectroscopy revealed that the secondary structure of protein differed between raw and roasted golden flaxseeds in terms of the percentages and ratio of {alpha}-helixes and {beta}-sheets in the mid-IR range at the cellular level. By using multicomponent peak modelling, the results show that the roasting reduced (P <0.05) the percentage of {alpha}-helixes (from 47.1% to 36.1%: S

  19. The beta-sheet to alpha-helix transition of beta-lactoglobulin monitored in real time with a microfabricated IR mixer

    NASA Astrophysics Data System (ADS)

    Kauffmann, Ekkehard; Darton, Nick; Gerwert, Klaus; Austin, Robert

    2001-03-01

    The helix to sheet transition of proteins, a crucial step in amylogenic diseases, is investigated with a new diffusional IR mixer using time-resolved FTIR spectroscopy capable of 400 microsecond time resolution. We show that the beta to alpha transition of beta-lactoglobulin proceeds via a compact molten globule b-sheet intermediate with an unusually short lifetime of 7 ms. Because the protein does not have to unfold for the beta-sheet to alpha-helix transition the energy barrier seems to be unexpectedly low. The rough energy landscape of a protein includes not only the steep free energy funnel that guides the unfolded protein into its compact native state

  20. High-Resolution Structure of a Self-Assembly-Competent Form of a Hydrophobic Peptide Captured in a Soluble [beta]-Sheet Scaffold

    SciTech Connect

    Makabe, Koki; Biancalana, Matthew; Yan, Shude; Tereshko, Valentina; Gawlak, Grzegorz; Miller-Auer, Hélène; Meredith, Stephen C.; Koide, Shohei

    2010-02-08

    {beta}-Rich self-assembly is a major structural class of polypeptides, but still little is known about its atomic structures and biophysical properties. Major impediments for structural and biophysical studies of peptide self-assemblies include their insolubility and heterogeneous composition. We have developed a model system, termed peptide self-assembly mimic (PSAM), based on the single-layer {beta}-sheet of Borrelia outer surface protein A. PSAM allows for the capture of a defined number of self-assembly-like peptide repeats within a water-soluble protein, making structural and energetic studies possible. In this work, we extend our PSAM approach to a highly hydrophobic peptide sequence. We show that a penta-Ile peptide (Ile{sub 5}), which is insoluble and forms {beta}-rich self-assemblies in aqueous solution, can be captured within the PSAM scaffold in a form capable of self-assembly. The 1.1-{angstrom} crystal structure revealed that the Ile{sub 5} stretch forms a highly regular {beta}-strand within this flat {beta}-sheet. Self-assembly models built with multiple copies of the crystal structure of the Ile5 peptide segment showed no steric conflict, indicating that this conformation represents an assembly-competent form. The PSAM retained high conformational stability, suggesting that the flat {beta}-strand of the Ile{sub 5} stretch primed for self-assembly is a low-energy conformation of the Ile{sub 5} stretch and rationalizing its high propensity for self-assembly. The ability of the PSAM to 'solubilize' an otherwise insoluble peptide stretch suggests the potential of the PSAM approach to the characterization of self-assembling peptides.

  1. A folding pathway for betapep-4 peptide 33mer: from unfolded monomers and beta-sheet sandwich dimers to well-structured tetramers.

    PubMed

    Mayo, K H; Ilyina, E

    1998-02-01

    It was recently reported that a de novo designed peptide 33mer, betapep-4, can form well-structured beta-sheet sandwich tetramers (Ilyina E, Roongta V, Mayo KH, 1997b, Biochemistry 36:5245-5250). For insight into the pathway of betapep-4 folding, the present study investigates the concentration dependence of betapep-4 self-association by using 1H-NMR pulsed-field gradient (PFG)-NMR diffusion measurements, and circular dichroism. Downfield chemically shifted alphaH resonances, found to arise only from the well-structured betapep-4 tetramer state, yield the fraction of tetramer within the oligomer equilibrium distribution. PFG-NMR-derived diffusion coefficients, D, provide a means for deriving the contribution of monomer and other oligomer states to this distribution. These data indicate that tetramer is the highest oligomer state formed, and that inclusion of monomer and dimer states in the oligomer distribution is sufficient to explain the concentration dependence of D values for betapep-4. Equilibrium constants calculated from these distributions [2.5 x 10(5) M(-1) for M-D and 1.2 x 10(4) M(-1) for D-T at 313 K] decrease only slightly, if at all, with decreasing temperature indicating a hydrophobically mediated, entropy-driven association/folding process. Conformational analyses using NMR and CD provide a picture where "random coil" monomers associate to form molten globule-like beta-sheet sandwich dimers that further associate and fold as well-structured tetramers. Betapep-4 folding is thermodynamically linked to self-association. As with folding of single-chain polypeptides, the final folding step to well-structured tetramer betapep-4 is rate limiting.

  2. Embryonic neural inducing factor churchill is not a DNA-binding zinc finger protein: solution structure reveals a solvent-exposed beta-sheet and zinc binuclear cluster.

    PubMed

    Lee, Brian M; Buck-Koehntop, Bethany A; Martinez-Yamout, Maria A; Dyson, H Jane; Wright, Peter E

    2007-08-31

    Churchill is a zinc-containing protein that is involved in neural induction during embryogenesis. At the time of its discovery, it was thought on the basis of sequence alignment to contain two zinc fingers of the C4 type. Further, binding of an N-terminal GST-Churchill fusion protein to a particular DNA sequence was demonstrated by immunoprecipitation selection assay, suggesting that Churchill may function as a transcriptional regulator by sequence-specific DNA binding. We show by NMR solution structure determination that, far from containing canonical C4 zinc fingers, the protein contains three bound zinc ions in novel coordination sites, including an unusual binuclear zinc cluster. The secondary structure of Churchill is also unusual, consisting of a highly solvent-exposed single-layer beta-sheet. Hydrogen-deuterium exchange and backbone relaxation measurements reveal that Churchill is unusually dynamic on a number of time scales, with the exception of regions surrounding the zinc coordinating sites, which serve to stabilize the otherwise unstructured N terminus and the single-layer beta-sheet. No binding of Churchill to the previously identified DNA sequence could be detected, and extensive searches using DNA sequence selection techniques could find no other DNA sequence that was bound by Churchill. Since the N-terminal amino acids of Churchill form part of the zinc-binding motif, the addition of a fusion protein at the N terminus causes loss of zinc and unfolding of Churchill. This observation most likely explains the published DNA-binding results, which would arise due to non-specific interaction of the unfolded protein in the immunoprecipitation selection assay. Since Churchill does not appear to bind DNA, we suggest that it may function in embryogenesis as a protein-interaction factor.

  3. A Tumor-specific MicroRNA Recognition System Facilitates the Accurate Targeting to Tumor Cells by Magnetic Nanoparticles

    PubMed Central

    Yu, Yingting; Yao, Yi; Yan, Hao; Wang, Rui; Zhang, Zhenming; Sun, Xiaodan; Zhao, Lingyun; Ao, Xiang; Xie, Zhen; Wu, Qiong

    2016-01-01

    Targeted therapy for cancer is a research area of great interest, and magnetic nanoparticles (MNPs) show great potential as targeted carriers for therapeutics. One important class of cancer biomarkers is microRNAs (miRNAs), which play a significant role in tumor initiation and progression. In this study, a cascade recognition system containing multiple plasmids, including a Tet activator, a lacI repressor gene driven by the TetOn promoter, and a reporter gene repressed by the lacI repressor and influenced by multiple endogenous miRNAs, was used to recognize cells that display miRNA signals that are characteristic of cancer. For this purpose, three types of signal miRNAs with high proliferation and metastasis abilities were chosen (miR-21, miR-145, and miR-9). The response of this system to the human breast cancer MCF-7 cell line was 3.2-fold higher than that to the human breast epithelial HBL100 cell line and almost 7.5-fold higher than that to human embryonic kidney HEK293T cells. In combination with polyethyleneimine-modified MNPs, this recognition system targeted the tumor location in situ in an animal model, and an ~42% repression of tumor growth was achieved. Our study provides a new combination of magnetic nanocarrier and gene therapy based on miRNAs that are active in vivo, which has potential for use in future cancer therapies. PMID:27138178

  4. Microscopic factors that control beta-sheet registry in amyloid fibrils formed by fragment 11-25 of amyloid beta peptide: insights from computer simulations.

    PubMed

    Negureanu, Lacramioara; Baumketner, Andrij

    2009-06-26

    Short fragments of amyloidogenic proteins are widely used as model systems in studies of amyloid formation. Fragment 11-25 of the amyloid beta protein involved in Alzheimer's disease (Abeta11-25) was recently shown to form amyloid fibrils composed of anti-parallel beta-sheets. Interestingly, fibrils grown under neutral and acidic conditions were seen to possess different registries of their inter-beta-strand hydrogen bonds. In an effort to explain the microscopic origin of this pH dependence, we studied Abeta11-25 fibrils using methods of theoretical modeling. Several structural models were built for fibrils at low and neutral pH levels and these were examined in short molecular dynamics simulations in explicit water. The models that displayed the lowest free energy, as estimated using an implicit solvent model, were selected as representative of the true fibrillar structure. It was shown that the registry of these models agrees well with the experimental results. At neutral pH, the main contribution to the free energy difference between the two registries comes from the electrostatic interactions. The charge group of the carboxy terminus makes a large contribution to these interactions and thus appears to have a critical role in determining the registry.

  5. Double-stranded helical twisted beta-sheet channels in crystals of gramicidin S grown in the presence of trifluoroacetic and hydrochloric acids.

    PubMed

    Llamas-Saiz, Antonio L; Grotenbreg, Gijsbert M; Overhand, Mark; van Raaij, Mark J

    2007-03-01

    Gramicidin S is a nonribosomally synthesized cyclic decapeptide antibiotic with twofold symmetry (Val-Orn-Leu-D-Phe-Pro)(2); a natural source is Bacillus brevis. Gramicidin S is active against Gram-positive and some Gram-negative bacteria. However, its haemolytic toxicity in humans limits its use as an antibiotic to certain topical applications. Synthetically obtained gramicidin S was crystallized from a solution containing water, methanol, trifluoroacetic acid and hydrochloric acid. The structure was solved and refined at 0.95 A resolution. The asymmetric unit contains 1.5 molecules of gramicidin S, two trifluoroacetic acid molecules and ten water molecules located and refined in 14 positions. One gramicidin S molecule has an exact twofold-symmetrical conformation; the other deviates from the molecular twofold symmetry. The cyclic peptide adopts an antiparallel beta-sheet secondary structure with two type II' beta-turns. These turns have the residues D-Phe and Pro at positions i + 1 and i + 2, respectively. In the crystals, the gramicidin S molecules line up into double-stranded helical channels that differ from those observed previously. The implications of the supramolecular structure for several models of gramicidin S conformation and assembly in the membrane are discussed.

  6. Recognition of Trimethylated Histone H3 Lysine 4 Facilitates the Recruitment of Transcription Post-Initiation Factors and pre-mRNA Splicing

    PubMed Central

    Sims, Robert J.; Millhouse, Scott; Chen, Chi-Fu; Lewis, Brian A.; Erdjument-Bromage, Hediye; Tempst, Paul; Manley, James L.; Reinberg, Danny

    2007-01-01

    Tri-methylation of histone H3 on lysine 4 (H3K4me3) localizes near the 5′ region of genes and is tightly associated with active loci. Several proteins, such as CHD1, BPTF, JMJD2A, and the ING tumor suppressor family, directly recognize this lysine methyl mark. However, how H3K4me3 recognition participates in active transcription remains poorly characterized. Here we identify specific CHD1-interacting proteins via H3K4me3 affinity purification, including numerous factors mediating post-initiation events. Conventional biochemical purification revealed a stable complex between CHD1 and components of the spliceosome. Depletion of CHD1 in extracts dramatically reduced splicing efficiency in vitro, indicating a functional link between CHD1 and the spliceosome. Knockdown of CHD1 and H3K4me3 levels by siRNA reduced association of U2 snRNP components with chromatin, and more importantly, altered the efficiency of pre-mRNA splicing on active genes in vivo. These findings suggest that methylated H3K4 serves to facilitate the competency of pre-mRNA maturation through the bridging of spliceosomal components to H3K4me3 via CHD1. PMID:18042460

  7. Conformational homogeneity in molecular recognition by proteolytic enzymes.

    PubMed

    Tyndall, J D; Fairlie, D P

    1999-01-01

    Crystal structures for several hundred protease-inhibitor complexes have been analysed and their superimpositions have been used to demonstrate a universal relationship between inhibitor/substrate conformation and molecular recognition by all aspartic, serine, cysteine and metallo proteases. Proteases universally recognize an extended beta strand conformation in all their peptidic (and non-peptidic) inhibitors and substrate analogues without significant exceptions. This conformational homogeneity is illustrated here for a subset of 180 protease-inhibitor structures which are displayed as (a) structural overlays of multiple inhibitors for each of eight aspartic, eight serine, six metallo and five cysteine proteases; (b) single inhibitors each bound to different proteases; and (c) Ramachandran plots of peptide or pseudo-peptide dihedral angle pairs which demonstrate beta strands (Phi -54 degrees to -173 degrees, Psi 24 degrees to 174 degrees ) like those normally found paired in proteins as beta sheets. However, unlike beta sheets, alpha and 3(10) helices, beta and gamma turns, where the folded main chain amide components are intramolecularly hydrogen bonded and thus unavailable for interaction with proteins, an inhibitor/substrate in an isolated beta strand conformation provides maximum exposure of its hydrogen bonding donors/acceptors and side chain components to a putative protease receptor. This analysis highlights the advantages of a strand conformation over other elements of secondary structure for protease recognition and may lead to generic strategies for inhibitor design.

  8. Hydrogen-1, carbon-13, and nitrogen-15 NMR spectroscopy of Anabaena 7120 flavodoxin: Assignment of. beta. -sheet and flavin binding site resonances and analysis of protein-flavin interactions

    SciTech Connect

    Stockman, B.J.; Krezel, A.M.; Markley, J.L. ); Leonhardt, K.G.; Straus, N.A. )

    1990-10-01

    Sequence-specific {sup 1}H and {sup 13}C NMR assignments have been made for residues that form the five-stranded parallel {beta}-sheet and the flavin mononucleotide (FMN) binding site of oxidized Anabaena 7120 flavodoxin. Interstrand nuclear Overhauser enhancements (NOEs) indicate that the {beta}-sheet arrangement is similar to that observed in the crystal structure of the 70% homologous long-chain flavodoxin from Anacystis nidulans. A total of 62 NOEs were identified: 8 between protons of bound FMN, 29 between protons of the protein in the flavin binding site, and 25 between protons of bound FMN and protons of the protein. These constraints were used to determine the localized solution structure of the FMN binding site. The electronic environment and conformation of the protein-bound flavin isoalloxazine ring were investigated by determining {sup 13}C-{sup 1}H coupling constants. The carbonyl edge of the flavin ring was found to be slightly polarized. The xylene ring was found to be nonplanar. Tyrosine 94, located adjacent to the flavin isoalloxazine ring, was shown to have a hindered aromatic ring flip rate.

  9. Students' understanding of primary and secondary protein structure: drawing secondary protein structure reveals student understanding better than simple recognition of structures.

    PubMed

    Harle, Marissa; Towns, Marcy H

    2013-01-01

    The interdisciplinary nature of biochemistry courses requires students to use both chemistry and biology knowledge to understand biochemical concepts. Research that has focused on external representations in biochemistry has uncovered student difficulties in comprehending and interpreting external representations in addition to a fragmented understanding of fundamental biochemistry concepts. This project focuses on students' understanding of primary and secondary protein structure and drawings (representations) of hydrogen-bonding in alpha helices and beta sheets. Analysis demonstrated that students can recognize and identify primary protein structure concepts when given a polypeptide. However, when asked to draw alpha helices and beta sheets and explain the role of hydrogen bonding their drawings students exhibited a fragmented understanding that lacked coherence. Faculty are encouraged to have students draw molecular level representations to make their mental models more explicit, complete, and coherent. This is in contrast to recognition and identification tasks, which do not adequately probe mental models and molecular level understanding.

  10. Functional stabilization of an RNA recognition motif by a noncanonical N-terminal expansion.

    PubMed

    Netter, Catharina; Weber, Gert; Benecke, Heike; Wahl, Markus C

    2009-07-01

    RNA recognition motifs (RRMs) constitute versatile macromolecular interaction platforms. They are found in many components of spliceosomes, in which they mediate RNA and protein interactions by diverse molecular strategies. The human U11/U12-65K protein of the minor spliceosome employs a C-terminal RRM to bind hairpin III of the U12 small nuclear RNA (snRNA). This interaction comprises one side of a molecular bridge between the U11 and U12 small nuclear ribonucleoprotein particles (snRNPs) and is reminiscent of the binding of the N-terminal RRMs in the major spliceosomal U1A and U2B'' proteins to hairpins in their cognate snRNAs. Here we show by mutagenesis and electrophoretic mobility shift assays that the beta-sheet surface and a neighboring loop of 65K C-terminal RRM are involved in RNA binding, as previously seen in canonical RRMs like the N-terminal RRMs of the U1A and U2B'' proteins. However, unlike U1A and U2B'', some 30 residues N-terminal of the 65K C-terminal RRM core are additionally required for stable U12 snRNA binding. The crystal structure of the expanded 65K C-terminal RRM revealed that the N-terminal tail adopts an alpha-helical conformation and wraps around the protein toward the face opposite the RNA-binding platform. Point mutations in this part of the protein had only minor effects on RNA affinity. Removal of the N-terminal extension significantly decreased the thermal stability of the 65K C-terminal RRM. These results demonstrate that the 65K C-terminal RRM is augmented by an N-terminal element that confers stability to the domain, and thereby facilitates stable RNA binding.

  11. Phage anti-immunocomplex assay for clomazone: two-site recognition increasing assay specificity and facilitating adaptation into an on-site format.

    PubMed

    Rossotti, M A; Carlomagno, M; González-Techera, A; Hammock, B D; Last, J; González-Sapienza, G

    2010-11-01

    The impact of the use of herbicides in agriculture can be minimized by compliance with good management practices that reduce the amount used and their release into the environment. Simple tests that provide real time on-site information about these chemicals are a major aid for these programs. In this work, we show that phage anti-immunocomplex assay (PHAIA), a method that uses phage-borne peptides to detect the formation of antibody-analyte immunocomplexes, is an advantageous technology to produce such field tests. A monoclonal antibody to the herbicide clomazone was raised and used in the development of conventional competitive and noncompetitive PHAIA immunoassays. The sensitivity attained with the PHAIA format was over 10 times higher than that of the competitive format. The cross-reactivity of the two methods was also compared using structurally related compounds, and we observed that the two-site binding of PHAIA "double-checks" the recognition of the analyte, thereby increasing the assay specificity. The positive readout of the noncompetitive PHAIA method allowed adaptation of the assay into a rapid and simple format where as little as 0.4 ng/mL clomazone (more than 10-fold lower than the proposed standard) in water samples from a rice field could be easily detected by simple visual inspection.

  12. Phage Anti-Immunocomplex Assay (PHAIA) for clomazone: Two-site recognition increases assay specificity and facilitates adaptation into a rapid on-site format

    PubMed Central

    Rossotti, M.A.; Carlomagno, M.; González-Techera, A.; Hammock, B.D.; Last, J.; González-Sapienza, G.

    2010-01-01

    The impact of the use of herbicides in agriculture can be minimized by compliance with good management practices that reduce the amount used and their release into the environment. Simple tests that provide real time on-site information about these chemicals are a major aid for these programs. In this work we show that PHAIA, a method that uses phage-borne peptides to detect the formation of antibody-analyte immunocomplexes, is an advantageous technology to produce such field tests. A monoclonal antibody to the herbicide clomazone was raised and used in the development of conventional competitive and noncompetitive PHAIA immunoassays. The sensitivity attained with the PHAIA format was over ten times higher than that of the competitive format. The cross-reactivity of the two methods was also compared by using structurally related compounds, and we observed that the two-site binding of PHAIA “double-checks” the recognition of the analyte, thereby increasing the assay specificity. The positive readout of the noncompetitive PHAIA method allowed adaptation of the assay into a rapid and simple format where as little as 0.4 ng/ml of clomazone (more than 10-fold lower than the proposed standard) in water samples from a rice field could be easily detected by simple visual inspection. PMID:20886819

  13. Structure of the DNA-Eco RI endonuclease recognition complex at 3 A resolution.

    PubMed

    McClarin, J A; Frederick, C A; Wang, B C; Greene, P; Boyer, H W; Grable, J; Rosenberg, J M

    1986-12-19

    The crystal structure of the complex between Eco RI endonuclease and the cognate oligonucleotide TCGCGAATTCGCG provides a detailed example of the structural basis of sequence-specific DNA-protein interactions. The structure was determined, to 3 A resolution, by the ISIR (iterative single isomorphous replacement) method with a platinum isomorphous derivative. The complex has twofold symmetry. Each subunit of the endonuclease is organized into an alpha/beta domain consisting a five-stranded beta sheet, alpha helices, and an extension, called the "arm," which wraps around the DNA. The large beta sheet consists of antiparallel and parallel motifs that form the foundations for the loops and alpha helices responsible for DNA strand scission and sequence-specific recognition, respectively. The DNA cleavage site is located in a cleft that binds the DNA backbone in the vicinity of the scissile bond. Sequence specificity is mediated by 12 hydrogen bonds originating from alpha helical recognition modules. Arg200 forms two hydrogen bonds with guanine while Glu144 and Arg145 form four hydrogen bonds to adjacent adenine residues. These interactions discriminate the Eco RI hexanucleotide GAATTC from all other hexanucleotides because any base substitution would require rupture of at least one of these hydrogen bonds.

  14. Increments to chiral recognition facilitating enantiomer separations of chiral acids, bases, and ampholytes using Cinchona-based zwitterion exchanger chiral stationary phases.

    PubMed

    Wernisch, Stefanie; Pell, Reinhard; Lindner, Wolfgang

    2012-07-01

    The intramolecular distances of anion and cation exchanger sites of zwitterionic chiral stationary phases represent potential tuning sites for enantiomer selectivity. In this contribution, we investigate the influence of alkanesulfonic acid chain length and flexibility on enantiomer separations of chiral acids, bases, and amphoteric molecules for six Cinchona alkaloid-based chiral stationary phases in comparison with structurally related anion and cation exchangers. Employing polar-organic elution conditions, we observed an intramolecular counterion effect for acidic analytes which led to reduced retention times but did not impair enantiomer selectivities. Retention of amphoteric analytes is based on simultaneous double ion pairing of their charged functional groups with the acidic and basic sites of the zwitterionic selectors. A chiral center in the vicinity of the strong cation exchanger site is vital for chiral separations of bases. Sterically demanding side chains are beneficial for separations of free amino acids. Enantioseparations of free (un-derivatized) peptides were particularly successful in stationary phases with straight-chain alkanesulfonic acid sites, pointing to a beneficial influence of more flexible moieties. In addition, we observed pseudo-enantiomeric behavior of quinine and quinidine-derived chiral stationary phases facilitating reversal of elution orders for all analytes.

  15. Identification of an E-selectin region critical for carbohydrate recognition and cell adhesion [published erratum appears in J Cell Biol 1993 Feb;120(4):1071

    PubMed Central

    1992-01-01

    E-selectin elicits cell adhesion by binding to the cell surface carbohydrate, sialyl Lewis X (sLe(x)). We evaluated the effects of mutations in the E-selectin lectin domain on the binding of a panel of anti-E-selectin mAbs and on the recognition of immobilized sLe(x) glycolipid. Functional residues were then superimposed onto a three- dimensional model of the E-selectin lectin domain. This analysis demonstrated that the epitopes recognized by blocking mAbs map to a patch near the antiparallel beta sheet derived from the NH2 and COOH termini of the lectin domain and two adjacent loops. Mutations that affect sLe(x) binding map to this same region. These results thus define a small region of the E-selectin lectin domain that is critical for carbohydrate recognition. PMID:1382077

  16. Plasminogen Substrate Recognition by the Streptokinase-Plasminogen Catalytic Complex Is Facilitated by Arg253, Lys256, and Lys257 in the Streptokinase β-Domain and Kringle 5 of the Substrate*

    PubMed Central

    Tharp, Anthony C.; Laha, Malabika; Panizzi, Peter; Thompson, Michael W.; Fuentes-Prior, Pablo; Bock, Paul E.

    2009-01-01

    Streptokinase (SK) conformationally activates the central zymogen of the fibrinolytic system, plasminogen (Pg). The SK·Pg* catalytic complex binds Pg as a specific substrate and cleaves it into plasmin (Pm), which binds SK to form the SK·Pm complex that propagates Pm generation. Catalytic complex formation is dependent on lysine-binding site (LBS) interactions between a Pg/Pm kringle and the SK COOH-terminal Lys414. Pg substrate recognition is also LBS-dependent, but the kringle and SK structural element(s) responsible have not been identified. SK mutants lacking Lys414 with Ala substitutions of charged residues in the SK β-domain 250-loop were evaluated in kinetic studies that resolved conformational and proteolytic Pg activation. Activation of [Lys]Pg and mini-Pg (containing only kringle 5 of Pg) by SK with Ala substitutions of Arg253, Lys256, and Lys257 showed decreases in the bimolecular rate constant for Pm generation, with nearly total inhibition for the SK Lys256/Lys257 double mutant. Binding of bovine Pg (BPg) to the SK·Pm complex containing fluorescently labeled Pm demonstrated LBS-dependent assembly of a SK·labeled Pm·BPg ternary complex, whereas BPg did not bind to the complex containing the SK Lys256/Lys257 mutant. BPg was activated by SK·Pm with a Km indistinguishable from the KD for BPg binding to form the ternary complex, whereas the SK Lys256/Lys257 mutant did not support BPg activation. We conclude that SK residues Arg253, Lys256, and Lys257 mediate Pg substrate recognition through kringle 5 of the [Lys]Pg and mini-Pg substrates. A molecular model of the SK·kringle 5 complex identifies the putative interactions involved in LBS-dependent Pg substrate recognition. PMID:19473980

  17. Facilitating Facilitators: Enhancing PBL through a Structured Facilitator Development Program

    ERIC Educational Resources Information Center

    Salinitri, Francine D.; Wilhelm, Sheila M.; Crabtree, Brian L.

    2015-01-01

    With increasing adoption of the problem-based learning (PBL) model, creative approaches to enhancing facilitator training and optimizing resources to maintain effective learning in small groups is essential. We describe a theoretical framework for the development of a PBL facilitator training program that uses the constructivist approach as the…

  18. Polymerization of immunoglobulin domains: A model system for the development of facilitated macromolecular assembly

    SciTech Connect

    Stevens, F.J.; Myatt, E.A.

    1991-01-01

    We have recently determined that monoclonal immunoglobulin light chains (Bence Jones proteins) are capable of reversible polymerization at room temperature. This property, as exhibited by immunoglobulin light chains (normally a component of an intact antibody molecule), may have novel implications for the development of molecular nanotechnology.'' The polymerization capability of the immunoglobulin light chain is associated with the so-called variable domain of this molecule. The variable domain is a durable, compact beta-sheet structure of molecular weight approximately 12,000. Most of the primary sequence variation is limited to one portion of the molecule, that portion associated with the contribution of immunoglobulin light chains to the recognition and binding of thousand of different antigens by antibodies. As a consequence of these variations, different light chains polymerize with different degrees of avidity, from negligible to extensive. The polymerization process depends on solution parameters such as Ph. Thus, polymerization might be induced at one pH and suppressed or reversed at another. Combinations of molecules of appropriate specificities could assemble into structures of predetermined three-dimensional forms and properties. These features suggest that Bence Jones proteins represent a powerful model system within which to develop empirical rules relevant to a technology of protein-based construction''. Development of these rules will require the combined efforts of biophysical and crystallographic studies, protein engineering, and molecular modeling. 53 refs., 5 figs.

  19. Polymerization of immunoglobulin domains: A model system for the development of facilitated macromolecular assembly

    SciTech Connect

    Stevens, F.J.; Myatt, E.A.

    1991-12-31

    We have recently determined that monoclonal immunoglobulin light chains (Bence Jones proteins) are capable of reversible polymerization at room temperature. This property, as exhibited by immunoglobulin light chains (normally a component of an intact antibody molecule), may have novel implications for the development of ``molecular nanotechnology.`` The polymerization capability of the immunoglobulin light chain is associated with the so-called variable domain of this molecule. The variable domain is a durable, compact beta-sheet structure of molecular weight approximately 12,000. Most of the primary sequence variation is limited to one portion of the molecule, that portion associated with the contribution of immunoglobulin light chains to the recognition and binding of thousand of different antigens by antibodies. As a consequence of these variations, different light chains polymerize with different degrees of avidity, from negligible to extensive. The polymerization process depends on solution parameters such as Ph. Thus, polymerization might be induced at one pH and suppressed or reversed at another. Combinations of molecules of appropriate specificities could assemble into structures of predetermined three-dimensional forms and properties. These features suggest that Bence Jones proteins represent a powerful model system within which to develop empirical rules relevant to a technology of protein-based ``construction``. Development of these rules will require the combined efforts of biophysical and crystallographic studies, protein engineering, and molecular modeling. 53 refs., 5 figs.

  20. Temporal regulation of kin recognition maintains recognition-cue diversity and suppresses cheating.

    PubMed

    Ho, Hsing-I; Shaulsky, Gad

    2015-05-28

    Kin recognition, the ability to distinguish kin from non-kin, can facilitate cooperation between relatives. Evolutionary theory predicts that polymorphism in recognition cues, which is essential for effective recognition, would be unstable. Individuals carrying rare recognition cues would benefit less from social interactions than individuals with common cues, leading to loss of the genetic-cue diversity. We test this evolutionary hypothesis in Dictyostelium discoideum, which forms multicellular fruiting bodies by aggregation and utilizes two polymorphic membrane proteins to facilitate preferential cooperation. Surprisingly, we find that rare recognition variants are tolerated and maintain their frequencies among incompatible majority during development. Although the rare variants are initially excluded from the aggregates, they subsequently rejoin the aggregate and produce spores. Social cheating is also refrained in late development, thus limiting the cost of chimerism. Our results suggest a potential mechanism to sustain the evolutionary stability of kin-recognition genes and to suppress cheating.

  1. Group collaboration in recognition memory.

    PubMed

    Clark, S E; Hori, A; Putnam, A; Martin, T P

    2000-11-01

    Group collaboration was examined in item and associative recognition. The present study distinguishes between group effects versus collaborative processes and defines the latter as interactive information exchange among group members. By that definition, many group effects do not involve collaboration. For example, group performance can exceed individual performance by pooling the increased resources of the group. Specifically, a group advantage can be obtained by deferring to a majority vote or to the group's best member. For both item and associative recognition, a group advantage was obtained that could not be accounted for by resource pooling. Collaborative facilitation was shown reliably in recognizing targets but not for rejecting distractors. PMID:11185784

  2. Recognition Tunneling

    PubMed Central

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-01-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically-functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode (“tethered molecule-pair” configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the “free analyte” configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules. PMID:20522930

  3. Conformational elasticity can facilitate TALE-DNA recognition.

    PubMed

    Lei, Hongxing; Sun, Jiya; Baldwin, Enoch P; Segal, David J; Duan, Yong

    2014-01-01

    Sequence-programmable transcription activator-like effector (TALE) proteins have emerged as a highly efficient tool for genome engineering. Recent crystal structures depict a transition between an open unbound solenoid and more compact DNA-bound solenoid formed by the 34 amino acid repeats. How TALEs switch conformation between these two forms without substantial energetic compensation, and how the repeat-variable di-residues (RVDs) discriminate between the cognate base and other bases still remain unclear. Computational analysis on these two aspects of TALE-DNA interaction mechanism has been conducted in order to achieve a better understanding of the energetics. High elasticity was observed in the molecular dynamics simulations of DNA-free TALE structure that started from the bound conformation where it sampled a wide range of conformations including the experimentally determined apo and bound conformations. This elastic feature was also observed in the simulations starting from the apo form which suggests low free energy barrier between the two conformations and small compensation required upon binding. To analyze binding specificity, we performed free energy calculations of various combinations of RVDs and bases using Poisson-Boltzmann surface area (PBSA) and other approaches. The PBSA calculations indicated that the native RVD-base structures had lower binding free energy than mismatched structures for most of the RVDs examined. Our theoretical analyses provided new insight on the dynamics and energetics of TALE-DNA binding mechanism.

  4. Acquisition of chemical recognition cues facilitates integration into ant societies

    PubMed Central

    2011-01-01

    Background Social insects maintain the integrity of their societies by discriminating between colony members and foreigners through cuticular hydrocarbon (CHC) signatures. Nevertheless, parasites frequently get access to social resources, for example through mimicry of host CHCs among other mechanisms. The origin of mimetic compounds, however, remains unknown in the majority of studies (biosynthesis vs. acquisition). Additionally, direct evidence is scarce that chemical mimicry is indeed beneficial to the parasites (e.g., by improving social acceptance). Results In the present study we demonstrated that the kleptoparasitic silverfish Malayatelura ponerophila most likely acquires CHCs directly from its host ant Leptogenys distinguenda by evaluating the transfer of a stable-isotope label from the cuticle of workers to the silverfish. In a second experiment, we prevented CHC pilfering by separating silverfish from their host for six or nine days. Chemical host resemblance as well as aggressive rejection behaviour by host ants was then quantified for unmanipulated and previously separated individuals. Separated individuals showed reduced chemical host resemblance and they received significantly more aggressive rejection behaviour than unmanipulated individuals. Conclusion Our study clarifies the mechanism of chemical mimicry in a social insect parasite in great detail. It shows empirically for the first time that social insect parasites are able to acquire CHCs from their host. Furthermore, it demonstrates that the accuracy of chemical mimicry can be crucial for social insect parasites by enhancing social acceptance and, thus, allowing successful exploitation. We discuss the results in the light of coevolutionary arms races between parasites and hosts. PMID:22133503

  5. Recognition-Based Physical Response to Facilitate EFL Learning

    ERIC Educational Resources Information Center

    Hwang, Wu-Yuin; Shih, Timothy K.; Yeh, Shih-Ching; Chou, Ke-Chien; Ma, Zhao-Heng; Sommool, Worapot

    2014-01-01

    This study, based on total physical response and cognitive psychology, proposed a Kinesthetic English Learning System (KELS), which utilized Microsoft's Kinect technology to build kinesthetic interaction with life-related contexts in English. A subject test with 39 tenth-grade students was conducted following empirical research method in…

  6. The crystal structure of the signal recognition particle Alu RNA binding heterodimer, SRP9/14.

    PubMed Central

    Birse, D E; Kapp, U; Strub, K; Cusack, S; Aberg, A

    1997-01-01

    The mammalian signal recognition particle (SRP) is an 11S cytoplasmic ribonucleoprotein that plays an essential role in protein sorting. SRP recognizes the signal sequence of the nascent polypeptide chain emerging from the ribosome, and targets the ribosome-nascent chain-SRP complex to the rough endoplasmic reticulum. The SRP consists of six polypeptides (SRP9, SRP14, SRP19, SRP54, SRP68 and SRP72) and a single 300 nucleotide RNA molecule. SRP9 and SRP14 proteins form a heterodimer that binds to the Alu domain of SRP RNA which is responsible for translation arrest. We report the first crystal structure of a mammalian SRP protein, that of the mouse SRP9/14 heterodimer, determined at 2.5 A resolution. SRP9 and SRP14 are found to be structurally homologous, containing the same alpha-beta-beta-beta-alpha fold. This we designate the Alu binding module (Alu bm), an additional member of the family of small alpha/beta RNA binding domains. The heterodimer has pseudo 2-fold symmetry and is saddle like, comprising a strongly curved six-stranded amphipathic beta-sheet with the four helices packed on the convex side and the exposed concave surface being lined with positively charged residues. PMID:9233785

  7. Facilitating Organizational Change.

    ERIC Educational Resources Information Center

    1999

    The first of the three papers in this symposium, "Conflicts that Arise in Small Group Facilitation: A Descriptive Study of Accounts, Actions, Outcomes, and Assessments" (Judith A. Kolb, William J. Rothwell), contains self-report verbatim accounts contributed by facilitators and the results of a literature review on small group conflict. "A Test of…

  8. A Facilitation Performance Aid.

    ERIC Educational Resources Information Center

    Chevalier, Roger

    1997-01-01

    Presents a guide, derived from the Situational Leadership model, which describes the process that should be used in facilitating a group discussion. The process includes preparation, assessment, diagnosis, prescription, development, reinforcement, and follow-up. Three figures depict the Situational Leadership model, the facilitation process, and…

  9. Chain length scaling of protein folding time: Beta sheet structures

    NASA Astrophysics Data System (ADS)

    Dimitrievski, K.; Kasemo, B.; Zhdanov, V. P.

    2000-07-01

    We present comprehensive 3D lattice Monte Carlo simulations of the folding kinetics of two-turn antiparallel β sheets. The model employed takes into account isotropic nonspecific interactions as in previous flexible heteropolymer models and also orientation-dependent monomer-monomer interactions, mimicking the formation of hydrogen bonds and chain rigidity. The chain length is varied from N=15 to 33. For each chain length, we calculate the fastest folding temperature, Tfast, folding temperature, Tfold, and glass-transition temperature, Tg. The time-averaged occupation probability of the native state is found to be nearly independent of N at all temperatures. The dependence of Tfast and Tfold on N is accordingly relatively weak. The temperature interval where the folding is fast rapidly decreases with increasing N. For the chain lengths chosen, Tfold slightly exceeds Tg. The dependence of the folding time τf on N is well fitted by using the power law, τf∝Nλ. The exponent λ is found to depend on temperature and on the distribution of nonspecific interactions in the chain. In particular, λ=2.7-4.0 at T=Tfast and 5.2 at T slightly below Tfold. Evaluating τf in real units at T near Tfold yields physically reasonable results.

  10. Beating the Heat - Fast Scanning Melts Silk Beta Sheet Crystals

    NASA Astrophysics Data System (ADS)

    Cebe, Peggy; Hu, Xiao; Kaplan, David L.; Zhuravlev, Evgeny; Wurm, Andreas; Arbeiter, Daniela; Schick, Christoph

    2013-01-01

    Beta-pleated-sheet crystals are among the most stable of protein secondary structures, and are responsible for the remarkable physical properties of many fibrous proteins, such as silk, or proteins forming plaques as in Alzheimer's disease. Previous thinking, and the accepted paradigm, was that beta-pleated-sheet crystals in the dry solid state were so stable they would not melt upon input of heat energy alone. Here we overturn that assumption and demonstrate that beta-pleated-sheet crystals melt directly from the solid state to become random coils, helices, and turns. We use fast scanning chip calorimetry at 2,000 K/s and report the first reversible thermal melting of protein beta-pleated-sheet crystals, exemplified by silk fibroin. The similarity between thermal melting behavior of lamellar crystals of synthetic polymers and beta-pleated-sheet crystals is confirmed. Significance for controlling beta-pleated-sheet content during thermal processing of biomaterials, as well as towards disease therapies, is envisioned based on these new findings.

  11. Beating the Heat: Fast Scanning Melts Beta Sheet Crystals

    NASA Astrophysics Data System (ADS)

    Cebe, Peggy; Hu, Xiao; Kaplan, David; Zhuravlev, Evgeny; Wurm, Andreas; Arbeiter, Daniella; Schick, Christoph

    2014-03-01

    Beta-pleated-sheet crystals are among the most stable of protein secondary structures, and are responsible for the remarkable physical properties of many fibrous proteins, such as silk. Previous thinking was that beta-pleated-sheet crystals in the dry solid state would not melt upon input of heat energy alone. Indeed, at conventional heating rates (~1-50 °C/min), silk exhibits its glass transition (~175 °C), followed by cold crystallization, and then by immediate thermal degradation beginning at about 225 °C. Here we demonstrate that beta-pleated-sheet crystals can melt directly from the solid state to become random coils, helices, and turns. We use fast scanning chip calorimetry at 2,000 K/s to avoid thermal degradation, and report the first reversible thermal melting of protein beta-pleated-sheet crystals, exemplified by silk fibroin. The similarity between thermal melting behavior of lamellar crystals of synthetic polymers and beta-pleated-sheet crystals is confirmed. The authors acknowledge support from the National Science Foundation and German Academic Exchange Service DAAD; EZ acknowledges a European Union funded Marie Curie EST fellowship (ADVATEC); XH and DK acknowledge NIH P41 Tissue Engineering Resource Center.

  12. Improving Transcription of Qualitative Research Interviews with Speech Recognition Technology.

    ERIC Educational Resources Information Center

    Fogg, Terry; Wightman, Colin W.

    The recent development of high-quality voice recognition software greatly facilitates the production of transcriptions for research and allows for objective and full transcription as well as annotated interpretation. Commercial speech recognition programs that are appropriate for generating transcriptions are available from a number of vendors,…

  13. Environmental Identity Development through Social Interactions, Action, and Recognition

    ERIC Educational Resources Information Center

    Stapleton, Sarah Riggs

    2015-01-01

    This article uses sociocultural identity theory to explore how practice, action, and recognition can facilitate environmental identity development. Recognition, a construct not previously explored in environmental identity literature, is particularly examined. The study is based on a group of diverse teens who traveled to South Asia to participate…

  14. A smoothness constraint on the development of object recognition.

    PubMed

    Wood, Justin N

    2016-08-01

    Understanding how the brain learns to recognize objects is one of the ultimate goals in the cognitive sciences. To date, however, we have not yet characterized the environmental factors that cause object recognition to emerge in the newborn brain. Here, I present the results of a high-throughput controlled-rearing experiment that examined whether the development of object recognition requires experience with temporally smooth visual objects. When newborn chicks (Gallus gallus) were raised with virtual objects that moved smoothly over time, the chicks developed accurate color recognition, shape recognition, and color-shape binding abilities. In contrast, when newborn chicks were raised with virtual objects that moved non-smoothly over time, the chicks' object recognition abilities were severely impaired. These results provide evidence for a "smoothness constraint" on newborn object recognition. Experience with temporally smooth objects facilitates the development of object recognition. PMID:27208825

  15. The coevolution of recognition and social behavior.

    PubMed

    Smead, Rory; Forber, Patrick

    2016-01-01

    Recognition of behavioral types can facilitate the evolution of cooperation by enabling altruistic behavior to be directed at other cooperators and withheld from defectors. While much is known about the tendency for recognition to promote cooperation, relatively little is known about whether such a capacity can coevolve with the social behavior it supports. Here we use evolutionary game theory and multi-population dynamics to model the coevolution of social behavior and recognition. We show that conditional harming behavior enables the evolution and stability of social recognition, whereas conditional helping leads to a deterioration of recognition ability. Expanding the model to include a complex game where both helping and harming interactions are possible, we find that conditional harming behavior can stabilize recognition, and thereby lead to the evolution of conditional helping. Our model identifies a novel hypothesis for the evolution of cooperation: conditional harm may have coevolved with recognition first, thereby helping to establish the mechanisms necessary for the evolution of cooperation. PMID:27225673

  16. Window Size Impact in Human Activity Recognition

    PubMed Central

    Banos, Oresti; Galvez, Juan-Manuel; Damas, Miguel; Pomares, Hector; Rojas, Ignacio

    2014-01-01

    Signal segmentation is a crucial stage in the activity recognition process; however, this has been rarely and vaguely characterized so far. Windowing approaches are normally used for segmentation, but no clear consensus exists on which window size should be preferably employed. In fact, most designs normally rely on figures used in previous works, but with no strict studies that support them. Intuitively, decreasing the window size allows for a faster activity detection, as well as reduced resources and energy needs. On the contrary, large data windows are normally considered for the recognition of complex activities. In this work, we present an extensive study to fairly characterize the windowing procedure, to determine its impact within the activity recognition process and to help clarify some of the habitual assumptions made during the recognition system design. To that end, some of the most widely used activity recognition procedures are evaluated for a wide range of window sizes and activities. From the evaluation, the interval 1–2 s proves to provide the best trade-off between recognition speed and accuracy. The study, specifically intended for on-body activity recognition systems, further provides designers with a set of guidelines devised to facilitate the system definition and configuration according to the particular application requirements and target activities. PMID:24721766

  17. The coevolution of recognition and social behavior

    PubMed Central

    Smead, Rory; Forber, Patrick

    2016-01-01

    Recognition of behavioral types can facilitate the evolution of cooperation by enabling altruistic behavior to be directed at other cooperators and withheld from defectors. While much is known about the tendency for recognition to promote cooperation, relatively little is known about whether such a capacity can coevolve with the social behavior it supports. Here we use evolutionary game theory and multi-population dynamics to model the coevolution of social behavior and recognition. We show that conditional harming behavior enables the evolution and stability of social recognition, whereas conditional helping leads to a deterioration of recognition ability. Expanding the model to include a complex game where both helping and harming interactions are possible, we find that conditional harming behavior can stabilize recognition, and thereby lead to the evolution of conditional helping. Our model identifies a novel hypothesis for the evolution of cooperation: conditional harm may have coevolved with recognition first, thereby helping to establish the mechanisms necessary for the evolution of cooperation. PMID:27225673

  18. Window size impact in human activity recognition.

    PubMed

    Banos, Oresti; Galvez, Juan-Manuel; Damas, Miguel; Pomares, Hector; Rojas, Ignacio

    2014-01-01

    Signal segmentation is a crucial stage in the activity recognition process; however, this has been rarely and vaguely characterized so far. Windowing approaches are normally used for segmentation, but no clear consensus exists on which window size should be preferably employed. In fact, most designs normally rely on figures used in previous works, but with no strict studies that support them. Intuitively, decreasing the window size allows for a faster activity detection, as well as reduced resources and energy needs. On the contrary, large data windows are normally considered for the recognition of complex activities. In this work, we present an extensive study to fairly characterize the windowing procedure, to determine its impact within the activity recognition process and to help clarify some of the habitual assumptions made during the recognition system design. To that end, some of the most widely used activity recognition procedures are evaluated for a wide range of window sizes and activities. From the evaluation, the interval 1-2 s proves to provide the best trade-off between recognition speed and accuracy. The study, specifically intended for on-body activity recognition systems, further provides designers with a set of guidelines devised to facilitate the system definition and configuration according to the particular application requirements and target activities. PMID:24721766

  19. Age of Acquisition and Sensitivity to Gender in Spanish Word Recognition

    ERIC Educational Resources Information Center

    Foote, Rebecca

    2014-01-01

    Speakers of gender-agreement languages use gender-marked elements of the noun phrase in spoken-word recognition: A congruent marking on a determiner or adjective facilitates the recognition of a subsequent noun, while an incongruent marking inhibits its recognition. However, while monolinguals and early language learners evidence this…

  20. The Role of Active Exploration of 3D Face Stimuli on Recognition Memory of Facial Information

    ERIC Educational Resources Information Center

    Liu, Chang Hong; Ward, James; Markall, Helena

    2007-01-01

    Research on face recognition has mainly relied on methods in which observers are relatively passive viewers of face stimuli. This study investigated whether active exploration of three-dimensional (3D) face stimuli could facilitate recognition memory. A standard recognition task and a sequential matching task were employed in a yoked design.…

  1. Self-Recognition in Live Videos by Young Children: Does Video Training Help?

    ERIC Educational Resources Information Center

    Demir, Defne; Skouteris, Helen

    2010-01-01

    The overall aim of the experiment reported here was to establish whether self-recognition in live video can be facilitated when live video training is provided to children aged 2-2.5 years. While the majority of children failed the test of live self-recognition prior to video training, more than half exhibited live self-recognition post video…

  2. Middle region of the Borrelia burgdorferi surface-located protein 1 (Lmp1) interacts with host chondroitin-6-sulfate and independently facilitates infection

    PubMed Central

    Yang, Xiuli; Lin, Yi-Pin; Heselpoth, Ryan D.; Buyuktanir, Ozlem; Qin, Jinhong; Kung, Faith; Nelson, Daniel C.; Leong, John M.; Pal, Utpal

    2015-01-01

    Summary Borrelia burgdorferi surface-located membrane protein 1, also known as Lmp1, has been shown to play critical roles in pathogen evasion of host-acquired immune defenses, thereby facilitating persistent infection. Lmp1 possesses three regions representing potentially discrete domains, Lmp1N, Lmp1M, and Lmp1C. Due to its insignificant homology to known proteins, how Lmp1 or its specific regions contribute to microbial biology and infection remains enigmatic. Here we show that distinct from Lmp1N and Lmp1C, Lmp1M is composed of at least 70% alpha helices and completely lacks recognizable beta sheets. The region binds to host glycosaminoglycan chondroitin-6-sulfate molecules and facilitates mammalian cell attachment, suggesting an adhesin function of Lmp1M. Phenotypic analysis of the Lmp1-deficient mutant engineered to produce Lmp1M on the microbial surface suggests that Lmp1M can independently support B. burgdorferi infectivity in murine hosts. Further exploration of functions of Lmp1 distinct regions will shed new light on the intriguing biology and infectivity of spirochetes and help develop novel interventions to combat Lyme disease. PMID:26247174

  3. Understanding Facilitation: Theory and Principles.

    ERIC Educational Resources Information Center

    Hogan, Christine

    This book introduces newcomers to the concept of facilitation, and it presents a critical analysis of established and current theory on facilitation for existing practitioners. The following are among the topics discussed: (1) emergence of the field of facilitation; (2) development of facilitation in management; (3) development of facilitation in…

  4. Relationship between listeners' nonnative speech recognition and categorization abilities

    PubMed Central

    Atagi, Eriko; Bent, Tessa

    2015-01-01

    Enhancement of the perceptual encoding of talker characteristics (indexical information) in speech can facilitate listeners' recognition of linguistic content. The present study explored this indexical-linguistic relationship in nonnative speech processing by examining listeners' performance on two tasks: nonnative accent categorization and nonnative speech-in-noise recognition. Results indicated substantial variability across listeners in their performance on both the accent categorization and nonnative speech recognition tasks. Moreover, listeners' accent categorization performance correlated with their nonnative speech-in-noise recognition performance. These results suggest that having more robust indexical representations for nonnative accents may allow listeners to more accurately recognize the linguistic content of nonnative speech. PMID:25618098

  5. Building Group Recognition.

    ERIC Educational Resources Information Center

    Chartier, George

    1994-01-01

    Discusses the value of name recognition for theater companies. Describes steps toward identity and recognition, analyzing the group, the mission statement, symbolic logic, designing and identity, developing a communications plan, and meaningful activities. (SR)

  6. Speech recognition and understanding

    SciTech Connect

    Vintsyuk, T.K.

    1983-05-01

    This article discusses the automatic processing of speech signals with the aim of finding a sequence of works (speech recognition) or a concept (speech understanding) being transmitted by the speech signal. The goal of the research is to develop an automatic typewriter that will automatically edit and type text under voice control. A dynamic programming method is proposed in which all possible class signals are stored, after which the presented signal is compared to all the stored signals during the recognition phase. Topics considered include element-by-element recognition of words of speech, learning speech recognition, phoneme-by-phoneme speech recognition, the recognition of connected speech, understanding connected speech, and prospects for designing speech recognition and understanding systems. An application of the composition dynamic programming method for the solution of basic problems in the recognition and understanding of speech is presented.

  7. Facilitative Strategies in Action.

    ERIC Educational Resources Information Center

    Fuller, Thara M. A.; Haugabrook, Adrian K.

    2001-01-01

    Describes campus-based strategies to facilitate collaboration by examining the process of restructuring a division of student affairs as an educational partner with academic affairs. Describes three collaborative efforts at the University of Massachusetts Boston: the Beacon Leadership Project, the Diversity Research Initiative, and the Beacon…

  8. The Inclusion Facilitator's Guide

    ERIC Educational Resources Information Center

    Jorgensen, Cheryl M.; Schuh, Mary C.; Nisbet, Jan

    2005-01-01

    Inclusion facilitators are educators who do more than teach children with disabilities--they advocate for change in schools and communities, sparking a passion for inclusion in teachers, administrators, and families and giving them the practical guidance they need to make it work. This is an essential new role in today's schools, and this guide…

  9. Facilitating Cognitive Development.

    ERIC Educational Resources Information Center

    Schwebel, Milton

    1985-01-01

    Human cognition research is shifting away from the importance of IQ and is emphasizing the stimulation and acceleration of a child's mental development. The emerging field of instructional psychology is trying to facilitate cognitive development. Current experimental programs--a university-school project in Belgium and a family project in…

  10. Formation of Freirian Facilitators.

    ERIC Educational Resources Information Center

    Noble, Phyllis

    This paper is written for people who are already familiar with the philosophy and methodology of Paulo Freire's liberatory education and are interested in creating a formation program for adult education facilitators using his ideas. The author describes the paper as "a collection of thoughts, of things to consider," when organizing such a…

  11. Facilitating Distance Education.

    ERIC Educational Resources Information Center

    Rossman, Mark H., Ed.; Rossman, Maxine E., Ed.

    1995-01-01

    This collection of articles on distance learning reflects the perspectives and concerns of the learner and the facilitator of learning in distance education setting. Eight chapters are included: (1) "The Evolution and Advantages of Distance Education" (John E. Cantelon) traces the history of distance education and demonstrates how it transcends…

  12. Facilitation of Adult Development

    ERIC Educational Resources Information Center

    Boydell, Tom

    2016-01-01

    Taking an autobiographical approach, I tell the story of my experiences facilitating adult development, in a polytechnic and as a management consultant. I relate these to a developmental framework of Modes of Being and Learning that I created and elaborated with colleagues. I connect this picture with a number of related models, theories,…

  13. Profiles of Discourse Recognition

    ERIC Educational Resources Information Center

    Singer, Murray

    2013-01-01

    A discourse recognition theory derived from more general memory formulations would be broad in its psychological implications. This study compared discourse recognition with some established profiles of item recognition. Participants read 10 stories either once or twice each. They then rated their confidence in recognizing explicit, paraphrased,…

  14. Exploring Biomolecular Recognition by Modeling and Simulation

    NASA Astrophysics Data System (ADS)

    Wade, Rebecca

    2007-12-01

    Biomolecular recognition is complex. The balance between the different molecular properties that contribute to molecular recognition, such as shape, electrostatics, dynamics and entropy, varies from case to case. This, along with the extent of experimental characterization, influences the choice of appropriate computational approaches to study biomolecular interactions. I will present computational studies in which we aim to make concerted use of bioinformatics, biochemical network modeling and molecular simulation techniques to study protein-protein and protein-small molecule interactions and to facilitate computer-aided drug design.

  15. Covert face recognition relies on affective valence in congenital prosopagnosia.

    PubMed

    Bate, Sarah; Haslam, Catherine; Jansari, Ashok; Hodgson, Timothy L

    2009-06-01

    Dominant accounts of covert recognition in prosopagnosia assume subthreshold activation of face representations created prior to onset of the disorder. Yet, such accounts cannot explain covert recognition in congenital prosopagnosia, where the impairment is present from birth. Alternatively, covert recognition may rely on affective valence, yet no study has explored this possibility. The current study addressed this issue in 3 individuals with congenital prosopagnosia, using measures of the scanpath to indicate recognition. Participants were asked to memorize 30 faces paired with descriptions of aggressive, nice, or neutral behaviours. In a later recognition test, eye movements were monitored while participants discriminated studied from novel faces. Sampling was reduced for studied--nice compared to studied--aggressive faces, and performance for studied--neutral and novel faces fell between these two conditions. This pattern of findings suggests that (a) positive emotion can facilitate processing in prosopagnosia, and (b) covert recognition may rely on emotional valence rather than familiarity.

  16. Immune recognition of citrullinated epitopes.

    PubMed

    Nguyen, Hai; James, Eddie A

    2016-10-01

    Conversion of arginine into citrulline is a post-translational modification that is observed in normal physiological processes. However, abnormal citrullination can provoke autoimmunity by generating altered self-epitopes that are specifically targeted by autoantibodies and T cells. In this review we discuss the recognition of citrullinated antigens in human autoimmune diseases and the role that this modification plays in increasing antigenic diversity and circumventing tolerance mechanisms. Early published work demonstrated that citrullinated proteins are specifically targeted by autoantibodies in rheumatoid arthritis and that citrullinated peptides are more readily presented to T cells by arthritis-susceptible HLA class II 'shared epitope' proteins. Emerging data support the relevance of citrullinated epitopes in other autoimmune diseases, including type 1 diabetes and multiple sclerosis, whose susceptible HLA haplotypes also preferentially present citrullinated peptides. In these settings, autoimmune patients have been shown to have elevated responses to citrullinated epitopes derived from tissue-specific antigens. Contrasting evidence implicates autophagy or perforin and complement-mediated membrane attack as inducers of ectopic citrullination. In either case, the peptidyl deiminases responsible for citrullination are activated in response to inflammation or insult, providing a mechanistic link between this post-translational modification and interactions with the environment and infection. As such, it is likely that immune recognition of citrullinated epitopes also plays a role in pathogen clearance. Indeed, our recent data suggest that responses to citrullinated peptides facilitate recognition of novel influenza strains. Therefore, increased understanding of responses to citrullinated epitopes may provide important insights about the initiation of autoimmunity and recognition of heterologous viruses. PMID:27531825

  17. Oxytocin improves emotion recognition for older males.

    PubMed

    Campbell, Anna; Ruffman, Ted; Murray, Janice E; Glue, Paul

    2014-10-01

    Older adults (≥60 years) perform worse than young adults (18-30 years) when recognizing facial expressions of emotion. The hypothesized cause of these changes might be declines in neurotransmitters that could affect information processing within the brain. In the present study, we examined the neuropeptide oxytocin that functions to increase neurotransmission. Research suggests that oxytocin benefits the emotion recognition of less socially able individuals. Men tend to have lower levels of oxytocin and older men tend to have worse emotion recognition than older women; therefore, there is reason to think that older men will be particularly likely to benefit from oxytocin. We examined this idea using a double-blind design, testing 68 older and 68 young adults randomly allocated to receive oxytocin nasal spray (20 international units) or placebo. Forty-five minutes afterward they completed an emotion recognition task assessing labeling accuracy for angry, disgusted, fearful, happy, neutral, and sad faces. Older males receiving oxytocin showed improved emotion recognition relative to those taking placebo. No differences were found for older females or young adults. We hypothesize that oxytocin facilitates emotion recognition by improving neurotransmission in the group with the worst emotion recognition.

  18. Facilitation as a teaching strategy : experiences of facilitators.

    PubMed

    Lekalakala-Mokgele, E

    2006-08-01

    Changes in nursing education involve the move from traditional teaching approaches that are teacher-centred to facilitation, a student centred approach. The student-centred approach is based on a philosophy of teaching and learning that puts the learner on centre-stage. The aim of this study was to identify the challenges of facilitators of learning using facilitation as a teaching method and recommend strategies for their (facilitators) development and support. A qualitative, explorative and contextual design was used. Four (4) universities in South Africa which utilize facilitation as a teaching/ learning process were identified and the facilitators were selected to be the sample of the study. The main question posed during in-depth group interviews was: How do you experience facilitation as a teaching/learning method?. Facilitators indicated different experiences and emotions when they first had to facilitate learning. All of them indicated that it was difficult to facilitate at the beginning as they were trained to lecture and that no format for facilitation was available. They experienced frustrations and anxieties as a result. The lack of knowledge of facilitation instilled fear in them. However they indicated that facilitation had many benefits for them and for the students. Amongst the ones mentioned were personal and professional growth. Challenges mentioned were the fear that they waste time and that they do not cover the content. It is therefore important that facilitation be included in the training of nurse educators. PMID:17131610

  19. Multimodal eye recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

    2010-04-01

    Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

  20. Kin Recognition in Bacteria.

    PubMed

    Wall, Daniel

    2016-09-01

    The ability of bacteria to recognize kin provides a means to form social groups. In turn these groups can lead to cooperative behaviors that surpass the ability of the individual. Kin recognition involves specific biochemical interactions between a receptor(s) and an identification molecule(s). Recognition specificity, ensuring that nonkin are excluded and kin are included, is critical and depends on the number of loci and polymorphisms involved. After recognition and biochemical perception, the common ensuing cooperative behaviors include biofilm formation, quorum responses, development, and swarming motility. Although kin recognition is a fundamental mechanism through which cells might interact, microbiologists are only beginning to explore the topic. This review considers both molecular and theoretical aspects of bacterial kin recognition. Consideration is also given to bacterial diversity, genetic relatedness, kin selection theory, and mechanisms of recognition. PMID:27359217

  1. Diagnostic odor recognition

    PubMed

    Rosenblatt; Phan; Desandre; Lobon; Hsu

    2000-10-01

    Many diseases, toxic ingestions, and intoxications have characteristic odors. These odors may provide diagnostic clues that affect rapid treatment long before laboratory confirmation or clinical deterioration. Odor recognition skills, similar to auscultation and palpation skills, require teaching and practical exposure. Dr. Goldfrank and colleagues recognized the importance of teaching odor recognition to emergency service providers. They proposed the "sniffing bar" method for odor recognition training. OBJECTIVES: (1) To identify the recognition rates of medically important odors among emergency care providers. (2) To investigate the effectiveness of teaching odor recognition. Hypothesis: The recognition rates of medically important odors will increase after teaching exposure. METHODS: The study exposed emergency care providers to 11 tubes of odors. Identifications of each substance were recorded. After corrective feedback, subjects were re-tested on their ability to identify the odors. Analysis of odor recognition improvement after teaching was done via chi-square test. RESULTS: Improvement in identification after teaching was seen in all odors. However, the improvement was significant only in the lesscommon substances because their initial recognition was especially low. Significant changes may improve with a larger sample size. Subjects often confuse the odors of alcohol with acetone, and wintergreen with camphor. CONCLUSIONS: The recognition rates are higher for the more-common odors, and lower for the less-common odors. Teaching exposures to the less well-known odors are effective and can significantly improve the recognition rate of these substances. Because odor recognition may affect rapid diagnosis and treatment of certain medical emergencies such as toxic ingestion, future studies should investigate the correlation between odor recognition and the ability to identify corresponding medical emergencies.

  2. Facilitating Discourse and Enhancing Teaching Presence: Using Mini Audio Presentations in Online Forums

    ERIC Educational Resources Information Center

    Dringus, Laurie P.; Snyder, Martha M.; Terrell, Steven R.

    2010-01-01

    The purpose of this pilot study was to determine if instructors' use of mini audio presentations (MAPs) in online discussions serves as an effective facilitation method, particularly when the content contains specific facilitation markers including reinforcement, recognition, and reward (three Rs). Instructors posted MAPs as audio file attachments…

  3. Can corrective feedback improve recognition memory?

    PubMed

    Kantner, Justin; Lindsay, D Stephen

    2010-06-01

    An understanding of the effects of corrective feedback on recognition memory can inform both recognition theory and memory training programs, but few published studies have investigated the issue. Although the evidence to date suggests that feedback does not improve recognition accuracy, few studies have directly examined its effect on sensitivity, and fewer have created conditions that facilitate a feedback advantage by encouraging controlled processing at test. In Experiment 1, null effects of feedback were observed following both deep and shallow encoding of categorized study lists. In Experiment 2, feedback robustly influenced response bias by allowing participants to discern highly uneven base rates of old and new items, but sensitivity remained unaffected. In Experiment 3, a false-memory procedure, feedback failed to attenuate false recognition of critical lures. In Experiment 4, participants were unable to use feedback to learn a simple category rule separating old items from new items, despite the fact that feedback was of substantial benefit in a nearly identical categorization task. The recognition system, despite a documented ability to utilize controlled strategic or inferential decision-making processes, appears largely impenetrable to a benefit of corrective feedback.

  4. Versatile architecture for image recognition applications

    NASA Astrophysics Data System (ADS)

    Sacramone, Anthony; Scola, Joseph; Shazeer, Dov J.

    1992-03-01

    Architectures for the development of image recognition algorithms must support the implementation of systematic procedures for solving image recognition problems. All too often, designers develop image recognition architectures in an ad hoc fashion which lacks the structure to meet long term needs. Vendors typically supply customers with standard image processing libraries and display tools. Combining these tools and formulating development strategies have remained stumbling blocks in the design of complete image recognition algorithm development environments. In this paper, an architecture is presented which provides a well defined framework, and at the same time is sufficiently flexible to accommodate images of multiple sensor and data types. The primary components of the architecture are: ground-truthing, preprocessing (which includes image processing and segmentation), feature extraction, classification, and performance analysis. Powerful and well defined data structures are exploited for each of the primary components. Groups of programs called tasks manipulate one or more of these data structures, each task belonging to one of the primary components. Multiple tasks can be executed in an unsupervised mode over an entire database of images. Results are then subjected to performance analysis and feedback. A description of the primary components and how they are integrated to facilitate the rapid prototyping and development of image recognition algorithms is presented.

  5. Moreland Recognition Program.

    ERIC Educational Resources Information Center

    Moreland Elementary School District, San Jose, CA.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: Recognition for special effort and achievement has been noted as a component of effective schools. Schools in the Moreland School District have effectively improved standards of discipline and achievement by providing forty-six different ways for children to receive positive recognition. Good…

  6. Infant Visual Recognition Memory

    ERIC Educational Resources Information Center

    Rose, Susan A.; Feldman, Judith F.; Jankowski, Jeffery J.

    2004-01-01

    Visual recognition memory is a robust form of memory that is evident from early infancy, shows pronounced developmental change, and is influenced by many of the same factors that affect adult memory; it is surprisingly resistant to decay and interference. Infant visual recognition memory shows (a) modest reliability, (b) good discriminant…

  7. RIG-I in RNA virus recognition

    PubMed Central

    Kell, Alison M.; Gale, Michael

    2015-01-01

    Antiviral immunity is initiated upon host recognition of viral products via non-self molecular patterns known as pathogen-associated molecular patterns (PAMPs). Such recognition initiates signaling cascades that induce intracellular innate immune defenses and an inflammatory response that facilitates development of the acquired immune response. The retinoic acid-inducible gene I (RIG-I) and the RIG-I-like receptor (RLR) protein family are key cytoplasmic pathogen recognition receptors that are implicated in the recognition of viruses across genera and virus families, including functioning as major sensors of RNA viruses, and promoting recognition of some DNA viruses. RIG-I, the charter member of the RLR family, is activated upon binding to PAMP RNA. Activated RIG-I signals by interacting with the adapter protein MAVS leading to a signaling cascade that activates the transcription factors IRF3 and NF-κB. These actions induce the expression of antiviral gene products and the production of type I and III interferons that lead to an antiviral state in the infected cell and surrounding tissue. RIG-I signaling is essential for the control of infection by many RNA viruses. Recently, RIG-I crosstalk with other pathogen recognition receptors and components of the inflammasome has been described. In this review, we discuss the current knowledge regarding the role of RIG-I in recognition of a variety of virus families and its role in programming the adaptive immune response through cross-talk with parallel arms of the innate immune system, including how RIG-I can be leveraged for antiviral therapy. PMID:25749629

  8. Facilitating post traumatic growth

    PubMed Central

    Turner, de Sales; Cox, Helen

    2004-01-01

    Background Whilst negative responses to traumatic injury have been well documented in the literature, there is a small but growing body of work that identifies posttraumatic growth as a salient feature of this experience. We contribute to this discourse by reporting on the experiences of 13 individuals who were traumatically injured, had undergone extensive rehabilitation and were discharged from formal care. All participants were injured through involvement in a motor vehicle accident, with the exception of one, who was injured through falling off the roof of a house. Methods In this qualitative study, we used an audio-taped in-depth interview with each participant as the means of data collection. Interviews were transcribed verbatim and analysed thematically to determine the participants' unique perspectives on the experience of recovery from traumatic injury. In reporting the findings, all participants' were given a pseudonym to assure their anonymity. Results Most participants indicated that their involvement in a traumatic occurrence was a springboard for growth that enabled them to develop new perspectives on life and living. Conclusion There are a number of contributions that health providers may make to the recovery of individuals who have been traumatically injured to assist them to develop new views of vulnerability and strength, make changes in relationships, and facilitate philosophical, physical and spiritual growth. PMID:15248894

  9. PCA facial expression recognition

    NASA Astrophysics Data System (ADS)

    El-Hori, Inas H.; El-Momen, Zahraa K.; Ganoun, Ali

    2013-12-01

    This paper explores and compares techniques for automatically recognizing facial actions in sequences of images. The comparative study of Facial Expression Recognition (FER) techniques namely Principal Component's analysis (PCA) and PCA with Gabor filters (GF) is done. The objective of this research is to show that PCA with Gabor filters is superior to the first technique in terms of recognition rate. To test and evaluates their performance, experiments are performed using real database by both techniques. The universally accepted five principal emotions to be recognized are: Happy, Sad, Disgust and Angry along with Neutral. The recognition rates are obtained on all the facial expressions.

  10. Pattern recognition technique

    NASA Technical Reports Server (NTRS)

    Hong, J. P.

    1971-01-01

    Technique operates regardless of pattern rotation, translation or magnification and successfully detects out-of-register patterns. It improves accuracy and reduces cost of various optical character recognition devices and page readers and provides data input to computer.

  11. Context based gait recognition

    NASA Astrophysics Data System (ADS)

    Bazazian, Shermin; Gavrilova, Marina

    2012-06-01

    Gait recognition has recently become a popular topic in the field of biometrics. However, the main hurdle is the insufficient recognition rate in the presence of low quality samples. The main focus of this paper is to investigate how the performance of a gait recognition system can be improved using additional information about behavioral patterns of users and the context in which samples have been taken. The obtained results show combining the context information with biometric data improves the performance of the system at a very low cost. The amount of improvement depends on the distinctiveness of the behavioral patterns and the quality of the gait samples. Using the appropriate distinctive behavioral models it is possible to achieve a 100% recognition rate.

  12. CASE Recognition Awards.

    ERIC Educational Resources Information Center

    Currents, 1985

    1985-01-01

    A total of 294 schools, colleges, and universities received prizes in this year's CASE Recognition program. Awards were given in: public relations programs, student recruitment, marketing, program pulications, news writing, fund raising, radio programming, school periodicals, etc. (MLW)

  13. Progress in fold recognition.

    PubMed

    Flöckner, H; Braxenthaler, M; Lackner, P; Jaritz, M; Ortner, M; Sippl, M J

    1995-11-01

    The prediction experiment reveals that fold recognition has become a powerful tool in structural biology. We applied our fold recognition technique to 13 target sequences. In two cases, replication terminating protein and prosequence of subtilisin, the predicted structures are very similar to the experimentally determined folds. For the first time, in a public blind test, the unknown structures of proteins have been predicted ahead of experiment to an accuracy approaching molecular detail. In two other cases the approximate folds have been predicted correctly. According to the assessors there were 12 recognizable folds among the target proteins. In our postprediction analysis we find that in 7 cases our fold recognition technique is successful. In several of the remaining cases the predicted folds have interesting features in common with the experimental results. We present our procedure, discuss the results, and comment on several fundamental and technical problems encountered in fold recognition.

  14. [Electrocardiograph beat pattern recognition].

    PubMed

    Zhou, Qunyi; Lu, Xudong; Duan, Huiling

    2005-02-01

    It is very important to recognize arrhythmia in clinical electrocardiography (ECG) analysis. The fundamental of beat pattern recognition is presented in this paper. Various prevalent methods for arrhythmia recognitiion are categorized and summarized, based on which the advantages and disadvantages among the methods are compared, and the main problems are discussed in depth. At last, the development trend of arrhythmia recognition technology is pointed out.

  15. Character Recognition Using Genetically Trained Neural Networks

    SciTech Connect

    Diniz, C.; Stantz, K.M.; Trahan, M.W.; Wagner, J.S.

    1998-10-01

    Computationally intelligent recognition of characters and symbols addresses a wide range of applications including foreign language translation and chemical formula identification. The combination of intelligent learning and optimization algorithms with layered neural structures offers powerful techniques for character recognition. These techniques were originally developed by Sandia National Laboratories for pattern and spectral analysis; however, their ability to optimize vast amounts of data make them ideal for character recognition. An adaptation of the Neural Network Designer soflsvare allows the user to create a neural network (NN_) trained by a genetic algorithm (GA) that correctly identifies multiple distinct characters. The initial successfid recognition of standard capital letters can be expanded to include chemical and mathematical symbols and alphabets of foreign languages, especially Arabic and Chinese. The FIN model constructed for this project uses a three layer feed-forward architecture. To facilitate the input of characters and symbols, a graphic user interface (GUI) has been developed to convert the traditional representation of each character or symbol to a bitmap. The 8 x 8 bitmap representations used for these tests are mapped onto the input nodes of the feed-forward neural network (FFNN) in a one-to-one correspondence. The input nodes feed forward into a hidden layer, and the hidden layer feeds into five output nodes correlated to possible character outcomes. During the training period the GA optimizes the weights of the NN until it can successfully recognize distinct characters. Systematic deviations from the base design test the network's range of applicability. Increasing capacity, the number of letters to be recognized, requires a nonlinear increase in the number of hidden layer neurodes. Optimal character recognition performance necessitates a minimum threshold for the number of cases when genetically training the net. And, the amount of

  16. Effectiveness of Emotion Recognition Training for Young Children with Developmental Delays

    ERIC Educational Resources Information Center

    Downs, Andrew; Strand, Paul

    2008-01-01

    Emotion recognition is a basic skill that is thought to facilitate development of social and emotional competence. There is little research available examining whether therapeutic or instructional interventions can improve the emotion recognition skill of young children with various developmental disabilities. Sixteen preschool children with…

  17. Integration of Partial Information within and across Modalities: Contributions to Spoken and Written Sentence Recognition

    ERIC Educational Resources Information Center

    Smith, Kimberly G.; Fogerty, Daniel

    2015-01-01

    Purpose: This study evaluated the extent to which partial spoken or written information facilitates sentence recognition under degraded unimodal and multimodal conditions. Method: Twenty young adults with typical hearing completed sentence recognition tasks in unimodal and multimodal conditions across 3 proportions of preservation. In the unimodal…

  18. The Essential Elements of Facilitation.

    ERIC Educational Resources Information Center

    Priest, Simon; Gass, Michael; Gillis, Lee

    Most organizations find it difficult to implement change, and only about 10 percent of learning from training and development experiences is actually applied in the workplace. This book advocates facilitation as a means of enhancing change and increasing productivity. Facilitation engages employees by enhancing the processes associated with their…

  19. Facilitating Dialogues about Racial Realities

    ERIC Educational Resources Information Center

    Quaye, Stephen John

    2014-01-01

    Background/Context: Facilitating dialogues about racial issues in higher education classroom settings continues to be a vexing problem facing postsecondary educators. In order for students to discuss race with their peers, they need skilled facilitators who are knowledgeable about racial issues and able to support students in these difficult…

  20. Movement Contributes to Infants' Recognition of the Human Form

    ERIC Educational Resources Information Center

    Christie, Tamara; Slaughter, Virginia

    2010-01-01

    Three experiments demonstrate that biological movement facilitates young infants' recognition of the whole human form. A body discrimination task was used in which 6-, 9-, and 12-month-old infants were habituated to typical human bodies and then shown scrambled human bodies at the test. Recovery of interest to the scrambled bodies was observed in…

  1. The Influence of Semantic Neighbours on Visual Word Recognition

    ERIC Educational Resources Information Center

    Yates, Mark

    2012-01-01

    Although it is assumed that semantics is a critical component of visual word recognition, there is still much that we do not understand. One recent way of studying semantic processing has been in terms of semantic neighbourhood (SN) density, and this research has shown that semantic neighbours facilitate lexical decisions. However, it is not clear…

  2. Visual Speech Primes Open-Set Recognition of Spoken Words

    ERIC Educational Resources Information Center

    Buchwald, Adam B.; Winters, Stephen J.; Pisoni, David B.

    2009-01-01

    Visual speech perception has become a topic of considerable interest to speech researchers. Previous research has demonstrated that perceivers neurally encode and use speech information from the visual modality, and this information has been found to facilitate spoken word recognition in tasks such as lexical decision (Kim, Davis, & Krins, 2004).…

  3. Page Recognition: Quantum Leap In Recognition Technology

    NASA Astrophysics Data System (ADS)

    Miller, Larry

    1989-07-01

    No milestone has proven as elusive as the always-approaching "year of the LAN," but the "year of the scanner" might claim the silver medal. Desktop scanners have been around almost as long as personal computers. And everyone thinks they are used for obvious desktop-publishing and business tasks like scanning business documents, magazine articles and other pages, and translating those words into files your computer understands. But, until now, the reality fell far short of the promise. Because it's true that scanners deliver an accurate image of the page to your computer, but the software to recognize this text has been woefully disappointing. Old optical-character recognition (OCR) software recognized such a limited range of pages as to be virtually useless to real users. (For example, one OCR vendor specified 12-point Courier font from an IBM Selectric typewriter: the same font in 10-point, or from a Diablo printer, was unrecognizable!) Computer dealers have told me the chasm between OCR expectations and reality is so broad and deep that nine out of ten prospects leave their stores in disgust when they learn the limitations. And this is a very important, very unfortunate gap. Because the promise of recognition -- what people want it to do -- carries with it tremendous improvements in our productivity and ability to get tons of written documents into our computers where we can do real work with it. The good news is that a revolutionary new development effort has led to the new technology of "page recognition," which actually does deliver the promise we've always wanted from OCR. I'm sure every reader appreciates the breakthrough represented by the laser printer and page-makeup software, a combination so powerful it created new reasons for buying a computer. A similar breakthrough is happening right now in page recognition: the Macintosh (and, I must admit, other personal computers) equipped with a moderately priced scanner and OmniPage software (from Caere

  4. A multistream model of visual word recognition.

    PubMed

    Allen, Philip A; Smith, Albert F; Lien, Mei-Ching; Kaut, Kevin P; Canfield, Angie

    2009-02-01

    Four experiments are reported that test a multistream model of visual word recognition, which associates letter-level and word-level processing channels with three known visual processing streams isolated in macaque monkeys: the magno-dominated (MD) stream, the interblob-dominated (ID) stream, and the blob-dominated (BD) stream (Van Essen & Anderson, 1995). We show that mixing the color of adjacent letters of words does not result in facilitation of response times or error rates when the spatial-frequency pattern of a whole word is familiar. However, facilitation does occur when the spatial-frequency pattern of a whole word is not familiar. This pattern of results is not due to different luminance levels across the different-colored stimuli and the background because isoluminant displays were used. Also, the mixed-case, mixed-hue facilitation occurred when different display distances were used (Experiments 2 and 3), so this suggests that image normalization can adjust independently of object size differences. Finally, we show that this effect persists in both spaced and unspaced conditions (Experiment 4)--suggesting that inappropriate letter grouping by hue cannot account for these results. These data support a model of visual word recognition in which lower spatial frequencies are processed first in the more rapid MD stream. The slower ID and BD streams may process some lower spatial frequency information in addition to processing higher spatial frequency information, but these channels tend to lose the processing race to recognition unless the letter string is unfamiliar to the MD stream--as with mixed-case presentation.

  5. Structures of the carbohydrate recognition domain of Ca2+-independent cargo receptors Emp46p and Emp47p.

    PubMed

    Satoh, Tadashi; Sato, Ken; Kanoh, Akira; Yamashita, Katsuko; Yamada, Yusuke; Igarashi, Noriyuki; Kato, Ryuichi; Nakano, Akihiko; Wakatsuki, Soichi

    2006-04-14

    Emp46p and Emp47p are type I membrane proteins, which cycle between the endoplasmic reticulum (ER) and the Golgi apparatus by vesicles coated with coat protein complexes I and II (COPI and COPII). They are considered to function as cargo receptors for exporting N-linked glycoproteins from the ER. We have determined crystal structures of the carbohydrate recognition domains (CRDs) of Emp46p and Emp47p of Saccharomyces cerevisiae, in the absence and presence of metal ions. Both proteins fold as a beta-sandwich, and resemble that of the mammalian ortholog, p58/ERGIC-53. However, the nature of metal binding is distinct from that of Ca(2+)-dependent p58/ERGIC-53. Interestingly, the CRD of Emp46p does not bind Ca(2+) ion but instead binds K(+) ion at the edge of a concave beta-sheet whose position is distinct from the corresponding site of the Ca(2+) ion in p58/ERGIC-53. Binding of K(+) ion to Emp46p appears essential for transport of a subset of glycoproteins because the Y131F mutant of Emp46p, which cannot bind K(+) ion fails to rescue the transport in disruptants of EMP46 and EMP47 genes. In contrast the CRD of Emp47p binds no metal ions at all. Furthermore, the CRD of Emp46p binds to glycoproteins carrying high mannosetype glycans and the is promoted by binding not the addition of Ca(2+) or K(+) ion in These results suggest that Emp46p can be regarded as a Ca(2+)-independent intracellular lectin at the ER exit sites.

  6. Probabilistic Open Set Recognition

    NASA Astrophysics Data System (ADS)

    Jain, Lalit Prithviraj

    Real-world tasks in computer vision, pattern recognition and machine learning often touch upon the open set recognition problem: multi-class recognition with incomplete knowledge of the world and many unknown inputs. An obvious way to approach such problems is to develop a recognition system that thresholds probabilities to reject unknown classes. Traditional rejection techniques are not about the unknown; they are about the uncertain boundary and rejection around that boundary. Thus traditional techniques only represent the "known unknowns". However, a proper open set recognition algorithm is needed to reduce the risk from the "unknown unknowns". This dissertation examines this concept and finds existing probabilistic multi-class recognition approaches are ineffective for true open set recognition. We hypothesize the cause is due to weak adhoc assumptions combined with closed-world assumptions made by existing calibration techniques. Intuitively, if we could accurately model just the positive data for any known class without overfitting, we could reject the large set of unknown classes even under this assumption of incomplete class knowledge. For this, we formulate the problem as one of modeling positive training data by invoking statistical extreme value theory (EVT) near the decision boundary of positive data with respect to negative data. We provide a new algorithm called the PI-SVM for estimating the unnormalized posterior probability of class inclusion. This dissertation also introduces a new open set recognition model called Compact Abating Probability (CAP), where the probability of class membership decreases in value (abates) as points move from known data toward open space. We show that CAP models improve open set recognition for multiple algorithms. Leveraging the CAP formulation, we go on to describe the novel Weibull-calibrated SVM (W-SVM) algorithm, which combines the useful properties of statistical EVT for score calibration with one-class and binary

  7. Toward hyperspectral face recognition

    NASA Astrophysics Data System (ADS)

    Robila, Stefan A.

    2008-02-01

    Face recognition continues to meet significant challenges in reaching accurate results and still remains one of the activities where humans outperform technology. An attractive approach in improving face identification is provided by the fusion of multiple imaging sources such as visible and infrared images. Hyperspectral data, i.e. images collected over hundreds of narrow contiguous light spectrum intervals constitute a natural choice for expanding face recognition image fusion, especially since it may provide information beyond the normal visible range, thus exceeding the normal human sensing. In this paper we investigate the efficiency of hyperspectral face recognition through an in house experiment that collected data in over 120 bands within the visible and near infrared range. The imagery was produced using an off the shelf sensor in both indoors and outdoors with the subjects being photographed from various angles. Further processing included spectra collection and feature extraction. Human matching performance based on spectral properties is discussed.

  8. Nucleic Acid Conjugated Nanomaterials for Enhanced Molecular Recognition

    PubMed Central

    Wang, Hao; Yang, Ronghua; Yang, Liu; Tan, Weihong

    2009-01-01

    Nucleic acids, whether designed or selected in vitro, play important roles in biosensing, medical diagnostics and therapy. Specifically, the conjugation of functional nucleic acid-based probe molecules and nanomaterials has resulted in an unprecedented improvement in the field of molecular recognition. With their unique physical and chemical properties, nanomaterials facilitate the sensing process and amplify the signal of recognition events. Thus, the coupling of nucleic acids with various nanomaterials opens up a promising future for molecular recognition. The literature offers a broad spectrum of recent advances in biosensing by employing different nano-platforms with designed nucleic acids, especially gold nanoparticles, carbon nanotubes, silica nanoparticles and quantum dots. The advantages of these novel combinations are discussed from the perspective of molecular recognition in chemistry, biology and medicine, along with the problems confronting future applications. PMID:19658387

  9. Phoneme fuzzy characterization in speech recognition systems

    NASA Astrophysics Data System (ADS)

    Beritelli, Francesco; Borrometi, Luca; Cuce, Antonino

    1997-10-01

    The acoustic approach to speech recognition has an important advantage compared with pattern recognition approach: it presents a lower complexity because it doesn't require explicit structures such as the hidden Markov model. In this work, we show how to characterize some phonetic classes of the Italian language in order to obtain a speaker and vocabulary independent speech recognition system. A phonetic data base is carried out with 200 continuous speech sentences of 12 speakers, 6 females and 6 males. The sentences are sampled at 8000 Hz and manual labelled with Asystem Sound Impression Software to obtain about 1600 units. We analyzed several speech parameters such as formants, LPC and reflection coefficients, energy, normal/differential zero crossing rate, cepstral and autocorrelation coefficients. The aim is the achievement of a phonetic recognizer to facilitate the so- called lexical access problem, that is to decode phonetic units into complete sense word strings. The knowledge is supplied to the recognizer in terms of fuzzy systems. The utilized software is called adaptive fuzzy modeler and it belongs to the rule generator family. A procedure has been implemented to integrate in the fuzzy system an 'expert' knowledge in order to obtain significant improvements in the recognition accuracy. Up to this point the tests show a recognition rate of 92% for the vocal class, 89% for the fricatives class and 94% for the nasal class, utilizing 1000 phonemes in phase of learning and 600 phonemes in phase of testing. Our intention is to complete the fuzzy recognizer extending this work to the other phonetic classes.

  10. Thermal-to-visible face recognition using partial least squares.

    PubMed

    Hu, Shuowen; Choi, Jonghyun; Chan, Alex L; Schwartz, William Robson

    2015-03-01

    Although visible face recognition has been an active area of research for several decades, cross-modal face recognition has only been explored by the biometrics community relatively recently. Thermal-to-visible face recognition is one of the most difficult cross-modal face recognition challenges, because of the difference in phenomenology between the thermal and visible imaging modalities. We address the cross-modal recognition problem using a partial least squares (PLS) regression-based approach consisting of preprocessing, feature extraction, and PLS model building. The preprocessing and feature extraction stages are designed to reduce the modality gap between the thermal and visible facial signatures, and facilitate the subsequent one-vs-all PLS-based model building. We incorporate multi-modal information into the PLS model building stage to enhance cross-modal recognition. The performance of the proposed recognition algorithm is evaluated on three challenging datasets containing visible and thermal imagery acquired under different experimental scenarios: time-lapse, physical tasks, mental tasks, and subject-to-camera range. These scenarios represent difficult challenges relevant to real-world applications. We demonstrate that the proposed method performs robustly for the examined scenarios. PMID:26366654

  11. A simple test of vocal individual recognition in wild meerkats.

    PubMed

    Townsend, Simon W; Allen, Colin; Manser, Marta B

    2012-04-23

    Individual recognition is thought to be a crucial ability facilitating the evolution of animal societies. Given its central importance, much research has addressed the extent of this capacity across the animal kingdom. Recognition of individuals vocally has received particular attention due, in part, to the insights it provides regarding the cognitive processes that underlie this skill. While much work has focused on vocal individual recognition in primates, there is currently very little data showing comparable skills in non-primate mammals under natural conditions. This may be because non-primate mammal societies do not provide obvious contexts in which vocal individual recognition can be rigorously tested. We addressed this gap in understanding by designing an experimental paradigm to test for individual recognition in meerkats (Suricata suricatta) without having to rely on naturally occurring social contexts. Results suggest that when confronted with a physically impossible scenario-the presence of the same conspecific meerkat in two different places-subjects responded more strongly than during the control, a physically possible setup. We argue that this provides the first clear evidence for vocal individual recognition in wild non-primate mammals and hope that this novel experimental design will allow more systematic cross-species comparisons of individual recognition under natural settings.

  12. Thermal-to-visible face recognition using partial least squares.

    PubMed

    Hu, Shuowen; Choi, Jonghyun; Chan, Alex L; Schwartz, William Robson

    2015-03-01

    Although visible face recognition has been an active area of research for several decades, cross-modal face recognition has only been explored by the biometrics community relatively recently. Thermal-to-visible face recognition is one of the most difficult cross-modal face recognition challenges, because of the difference in phenomenology between the thermal and visible imaging modalities. We address the cross-modal recognition problem using a partial least squares (PLS) regression-based approach consisting of preprocessing, feature extraction, and PLS model building. The preprocessing and feature extraction stages are designed to reduce the modality gap between the thermal and visible facial signatures, and facilitate the subsequent one-vs-all PLS-based model building. We incorporate multi-modal information into the PLS model building stage to enhance cross-modal recognition. The performance of the proposed recognition algorithm is evaluated on three challenging datasets containing visible and thermal imagery acquired under different experimental scenarios: time-lapse, physical tasks, mental tasks, and subject-to-camera range. These scenarios represent difficult challenges relevant to real-world applications. We demonstrate that the proposed method performs robustly for the examined scenarios.

  13. A simple test of vocal individual recognition in wild meerkats.

    PubMed

    Townsend, Simon W; Allen, Colin; Manser, Marta B

    2012-04-23

    Individual recognition is thought to be a crucial ability facilitating the evolution of animal societies. Given its central importance, much research has addressed the extent of this capacity across the animal kingdom. Recognition of individuals vocally has received particular attention due, in part, to the insights it provides regarding the cognitive processes that underlie this skill. While much work has focused on vocal individual recognition in primates, there is currently very little data showing comparable skills in non-primate mammals under natural conditions. This may be because non-primate mammal societies do not provide obvious contexts in which vocal individual recognition can be rigorously tested. We addressed this gap in understanding by designing an experimental paradigm to test for individual recognition in meerkats (Suricata suricatta) without having to rely on naturally occurring social contexts. Results suggest that when confronted with a physically impossible scenario-the presence of the same conspecific meerkat in two different places-subjects responded more strongly than during the control, a physically possible setup. We argue that this provides the first clear evidence for vocal individual recognition in wild non-primate mammals and hope that this novel experimental design will allow more systematic cross-species comparisons of individual recognition under natural settings. PMID:21992821

  14. Recognition for Employed Inventors.

    ERIC Educational Resources Information Center

    Sanders, Howard J.

    1980-01-01

    Presents arguments for monetary rewards and other forms of recognition by employers for inventions of employed inventors, particularly as the concept applies to stimulating innovativeness in America. Discusses the controversy of federally mandated compensation for employed inventors. The efforts of the American Chemical Society along these lines…

  15. Units of Word Recognition.

    ERIC Educational Resources Information Center

    Santa, Carol M.; And Others

    Both psychologists and reading specialists have been interested in whether words are processed letter by letter or in larger units. A reaction time paradigm was used to evaluate these options with interest focused on potential units of word recognition which might be functional within single syllable words. The basic paradigm involved presenting…

  16. Optical Character Recognition.

    ERIC Educational Resources Information Center

    Converso, L.; Hocek, S.

    1990-01-01

    This paper describes computer-based optical character recognition (OCR) systems, focusing on their components (the computer, the scanner, the OCR, and the output device); how the systems work; and features to consider in selecting a system. A list of 26 questions to ask to evaluate systems for potential purchase is included. (JDD)

  17. [Facial recognition and autism].

    PubMed

    Assumpçäo Júnior, F B; Sprovieri, M H; Kuczynski, E; Farinha, V

    1999-12-01

    Through the presentation of four facial expressions' illustrations, we evaluate the capacity of autistic children recognition, comparing with normal intelligence children and adults. The comparison of results was accomplished through the qui-square test. The differences observed were significant, showing that a disturbance of the facial expressions' perception is present in autistic children, and that it interferes directly in the social relationships.

  18. Recognition Memory for Pseudowords

    ERIC Educational Resources Information Center

    Greene, Robert L.

    2004-01-01

    Participants are more likely to give positive responses on a recognition test to pseudowords (pronounceable nonwords) than words. A series of experiments suggests that this difference reflects the greater overall familiarity of pseudowords than of words. Pseudowords receive higher ratings of similarity to a studied list than do words. Pseudowords…

  19. Microprocessor for speech recognition

    SciTech Connect

    Ishizuka, H.; Watari, M.; Sakoe, H.; Chiba, S.; Iwata, T.; Matsuki, T.; Kawakami, Y.

    1983-01-01

    A new single-chip microprocessor for speech recognition has been developed utilizing multi-processor architecture and pipelined structure. By DP-matching algorithm, the processor recognizes up to 340 isolated words or 40 connected words in realtime. 6 references.

  20. 1987 CASE Recognition Awards.

    ERIC Educational Resources Information Center

    Currents, 1987

    1987-01-01

    The 1987 CASE Recognition Awards are presented for: general excellence in programs; student recruitment marketing improvement; video public service announcements, news, and commercial spots; total publications; magazines of the decade; improvement in periodicals; photocommunications via print; designer of the year and series; and imagination in…

  1. Pattern recognition in bioinformatics.

    PubMed

    de Ridder, Dick; de Ridder, Jeroen; Reinders, Marcel J T

    2013-09-01

    Pattern recognition is concerned with the development of systems that learn to solve a given problem using a set of example instances, each represented by a number of features. These problems include clustering, the grouping of similar instances; classification, the task of assigning a discrete label to a given instance; and dimensionality reduction, combining or selecting features to arrive at a more useful representation. The use of statistical pattern recognition algorithms in bioinformatics is pervasive. Classification and clustering are often applied to high-throughput measurement data arising from microarray, mass spectrometry and next-generation sequencing experiments for selecting markers, predicting phenotype and grouping objects or genes. Less explicitly, classification is at the core of a wide range of tools such as predictors of genes, protein function, functional or genetic interactions, etc., and used extensively in systems biology. A course on pattern recognition (or machine learning) should therefore be at the core of any bioinformatics education program. In this review, we discuss the main elements of a pattern recognition course, based on material developed for courses taught at the BSc, MSc and PhD levels to an audience of bioinformaticians, computer scientists and life scientists. We pay attention to common problems and pitfalls encountered in applications and in interpretation of the results obtained.

  2. Learning curve of speech recognition.

    PubMed

    Kauppinen, Tomi A; Kaipio, Johanna; Koivikko, Mika P

    2013-12-01

    Speech recognition (SR) speeds patient care processes by reducing report turnaround times. However, concerns have emerged about prolonged training and an added secretarial burden for radiologists. We assessed how much proofing radiologists who have years of experience with SR and radiologists new to SR must perform, and estimated how quickly the new users become as skilled as the experienced users. We studied SR log entries for 0.25 million reports from 154 radiologists and after careful exclusions, defined a group of 11 experienced radiologists and 71 radiologists new to SR (24,833 and 122,093 reports, respectively). Data were analyzed for sound file and report lengths, character-based error rates, and words unknown to the SR's dictionary. Experienced radiologists corrected 6 characters for each report and for new users, 11. Some users presented a very unfavorable learning curve, with error rates not declining as expected. New users' reports were longer, and data for the experienced users indicates that their reports, initially equally lengthy, shortened over a period of several years. For most radiologists, only minor corrections of dictated reports were necessary. While new users adopted SR quickly, with a subset outperforming experienced users from the start, identification of users struggling with SR will help facilitate troubleshooting and support.

  3. Distributed nestmate recognition in ants

    PubMed Central

    Esponda, Fernando; Gordon, Deborah M.

    2015-01-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response. PMID:25833853

  4. Distributed nestmate recognition in ants.

    PubMed

    Esponda, Fernando; Gordon, Deborah M

    2015-05-01

    We propose a distributed model of nestmate recognition, analogous to the one used by the vertebrate immune system, in which colony response results from the diverse reactions of many ants. The model describes how individual behaviour produces colony response to non-nestmates. No single ant knows the odour identity of the colony. Instead, colony identity is defined collectively by all the ants in the colony. Each ant responds to the odour of other ants by reference to its own unique decision boundary, which is a result of its experience of encounters with other ants. Each ant thus recognizes a particular set of chemical profiles as being those of non-nestmates. This model predicts, as experimental results have shown, that the outcome of behavioural assays is likely to be variable, that it depends on the number of ants tested, that response to non-nestmates changes over time and that it changes in response to the experience of individual ants. A distributed system allows a colony to identify non-nestmates without requiring that all individuals have the same complete information and helps to facilitate the tracking of changes in cuticular hydrocarbon profiles, because only a subset of ants must respond to provide an adequate response.

  5. [Role of lyrics and melody in song recognition: why is song recognition faster?].

    PubMed

    Saito, Yoko; Sakuma, Naoko; Ishii, Kenji; Mizusawa, Hidehiro

    2009-12-01

    Two experiments were conducted to identify the role of lyrics and melody in song recognition. Experiment 1 (N = 30) investigated the ratings of familiarity, age of acquisition, retrievability of lyrics or melody, and happiness for 100 Japanese children's songs. In Experiment 2 (N = 31), a familiarity-judgment task was conducted involving three stimulus types-sung lyrics (SONG), spoken lyrics (LYRICS), and sung melody using the syllable/la/ (MELODY)--for two excerpts (beginning and middle locations). The participants were instructed to judge whether an excerpt sounded familiar as quickly as possible. The more familiar the songs, the easier could they be identified from the three stimulus types. SONG-response time (RT) was shorter than MELODY-RT for both beginning and middle, and than LYRICS-RT for the middle. The location effect emerged most prominently for LYRICS-RT. Our results suggest that interactively connected information of lyrics and melody may facilitate song recognition. Lyrics in the beginning might be an index only for certain, very familiar songs, whereas melody may play a facilitative role for song recognition regardless of location. PMID:20095443

  6. Supporting Quality Teachers with Recognition

    ERIC Educational Resources Information Center

    Andrews, Hans A.

    2011-01-01

    Value has been found in providing recognition and awards programs for excellent teachers. Research has also found a major lack of these programs in both the USA and in Australia. Teachers receiving recognition and awards for their teaching have praised recognition programs as providing motivation for them to continue high-level instruction.…

  7. Word Recognition in Auditory Cortex

    ERIC Educational Resources Information Center

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  8. Visual Recognition Memory across Contexts

    ERIC Educational Resources Information Center

    Jones, Emily J. H.; Pascalis, Olivier; Eacott, Madeline J.; Herbert, Jane S.

    2011-01-01

    In two experiments, we investigated the development of representational flexibility in visual recognition memory during infancy using the Visual Paired Comparison (VPC) task. In Experiment 1, 6- and 9-month-old infants exhibited recognition when familiarization and test occurred in the same room, but showed no evidence of recognition when…

  9. Protein crystallization facilitated by molecularly imprinted polymers

    PubMed Central

    Saridakis, Emmanuel; Khurshid, Sahir; Govada, Lata; Phan, Quan; Hawkins, Daniel; Crichlow, Gregg V.; Lolis, Elias; Reddy, Subrayal M.; Chayen, Naomi E.

    2011-01-01

    We present a previously undescribed initiative and its application, namely the design of molecularly imprinted polymers (MIPs) for producing protein crystals that are essential for determining high-resolution 3D structures of proteins. MIPs, also referred to as “smart materials,” are made to contain cavities capable of rebinding protein; thus the fingerprint of the protein created on the polymer allows it to serve as an ideal template for crystal formation. We have shown that six different MIPs induced crystallization of nine proteins, yielding crystals in conditions that do not give crystals otherwise. The incorporation of MIPs in screening experiments gave rise to crystalline hits in 8–10% of the trials for three target proteins. These hits would have been missed using other known nucleants. MIPs also facilitated the formation of large single crystals at metastable conditions for seven proteins. Moreover, the presence of MIPs has led to faster formation of crystals in all cases where crystals would appear eventually and to major improvement in diffraction in some cases. The MIPs were effective for their cognate proteins and also for other proteins, with size compatibility being a likely criterion for efficacy. Atomic force microscopy (AFM) measurements demonstrated specific affinity between the MIP cavities and a protein-functionalized AFM tip, corroborating our hypothesis that due to the recognition of proteins by the cavities, MIPs can act as nucleation-inducing substrates (nucleants) by harnessing the proteins themselves as templates. PMID:21690356

  10. Tracheal activity recognition based on acoustic signals.

    PubMed

    Olubanjo, Temiloluwa; Ghovanloo, Maysam

    2014-01-01

    Tracheal activity recognition can play an important role in continuous health monitoring for wearable systems and facilitate the advancement of personalized healthcare. Neck-worn systems provide access to a unique set of health-related data that other wearable devices simply cannot obtain. Activities including breathing, chewing, clearing the throat, coughing, swallowing, speech and even heartbeat can be recorded from around the neck. In this paper, we explore tracheal activity recognition using a combination of promising acoustic features from related work and apply simplistic classifiers including K-NN and Naive Bayes. For wearable systems in which low power consumption is of primary concern, we show that with a sub-optimal sampling rate of 16 kHz, we have achieved average classification results in the range of 86.6% to 87.4% using 1-NN, 3-NN, 5-NN and Naive Bayes. All classifiers obtained the highest recognition rate in the range of 97.2% to 99.4% for speech classification. This is promising to mitigate privacy concerns associated with wearable systems interfering with the user's conversations.

  11. Recognition of Teaching Excellence*

    PubMed Central

    Piascik, Peggy; Medina, Melissa; Pittenger, Amy; Rose, Renee; Creekmore, Freddy; Soltis, Robert; Bouldin, Alicia; Schwarz, Lindsay; Scott, Steven

    2010-01-01

    The 2008-2009 Task Force for the Recognition of Teaching Excellence was charged by the AACP Council of Faculties Leadership to examine teaching excellence by collecting best practices from colleges and schools of pharmacy, evaluating the literature to identify evidence-based criteria for excellent teaching, and recommending appropriate means to acknowledge and reward teaching excellence. This report defines teaching excellence and discusses a variety of ways to assess it, including student, alumni, peer, and self-assessment. The task force identifies important considerations that colleges and schools must address when establishing teaching recognition programs including the purpose, criteria, number and mix of awards, frequency, type of award, and method of nominating and determining awardees. The report concludes with recommendations for the academy to consider when establishing and revising teaching award programs. PMID:21301598

  12. Recognition of teaching excellence.

    PubMed

    Hammer, Dana; Piascik, Peggy; Medina, Melissa; Pittenger, Amy; Rose, Renee; Creekmore, Freddy; Soltis, Robert; Bouldin, Alicia; Schwarz, Lindsay; Scott, Steven

    2010-11-10

    The 2008-2009 Task Force for the Recognition of Teaching Excellence was charged by the AACP Council of Faculties Leadership to examine teaching excellence by collecting best practices from colleges and schools of pharmacy, evaluating the literature to identify evidence-based criteria for excellent teaching, and recommending appropriate means to acknowledge and reward teaching excellence. This report defines teaching excellence and discusses a variety of ways to assess it, including student, alumni, peer, and self-assessment. The task force identifies important considerations that colleges and schools must address when establishing teaching recognition programs including the purpose, criteria, number and mix of awards, frequency, type of award, and method of nominating and determining awardees. The report concludes with recommendations for the academy to consider when establishing and revising teaching award programs.

  13. Audio-visual gender recognition

    NASA Astrophysics Data System (ADS)

    Liu, Ming; Xu, Xun; Huang, Thomas S.

    2007-11-01

    Combining different modalities for pattern recognition task is a very promising field. Basically, human always fuse information from different modalities to recognize object and perform inference, etc. Audio-Visual gender recognition is one of the most common task in human social communication. Human can identify the gender by facial appearance, by speech and also by body gait. Indeed, human gender recognition is a multi-modal data acquisition and processing procedure. However, computational multimodal gender recognition has not been extensively investigated in the literature. In this paper, speech and facial image are fused to perform a mutli-modal gender recognition for exploring the improvement of combining different modalities.

  14. High School Facilitators and Inhibitors.

    ERIC Educational Resources Information Center

    Gnagey, William J.

    1981-01-01

    Teachers in a small high school nominated students whose classroom behavior facilitates or inhibits (disrupts) the learning process. These two groups were compared on locus of control, Maslow motive hierarchies, attitudes toward crime prevention, and achievement. Results are discussed and suggestions for helping disruptive students are made. (SJL)

  15. Producing Gestures Facilitates Route Learning

    PubMed Central

    So, Wing Chee; Ching, Terence Han-Wei; Lim, Phoebe Elizabeth; Cheng, Xiaoqin; Ip, Kit Yee

    2014-01-01

    The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air). Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2) without rehearsal or after rehearsal by mentally simulating the route, by drawing it, or by gesturing (either in the air or on paper). Participants who moved their hands (either in the form of gestures or drawing) recalled better than those who mentally simulated the routes and those who did not rehearse, suggesting that hand movements produced during rehearsal facilitate route learning. Interestingly, participants who gestured the routes in the air or on paper recalled better than those who drew them on paper in both experiments, suggesting that the facilitation effect of co-thought gesture holds for both verbal and nonverbal recall modalities. It is possibly because, co-thought gesture, as a kind of representational action, consolidates spatial sequence better than drawing and thus exerting more powerful influence on spatial representation. PMID:25426624

  16. Producing gestures facilitates route learning.

    PubMed

    So, Wing Chee; Ching, Terence Han-Wei; Lim, Phoebe Elizabeth; Cheng, Xiaoqin; Ip, Kit Yee

    2014-01-01

    The present study investigates whether producing gestures would facilitate route learning in a navigation task and whether its facilitation effect is comparable to that of hand movements that leave physical visible traces. In two experiments, we focused on gestures produced without accompanying speech, i.e., co-thought gestures (e.g., an index finger traces the spatial sequence of a route in the air). Adult participants were asked to study routes shown in four diagrams, one at a time. Participants reproduced the routes (verbally in Experiment 1 and non-verbally in Experiment 2) without rehearsal or after rehearsal by mentally simulating the route, by drawing it, or by gesturing (either in the air or on paper). Participants who moved their hands (either in the form of gestures or drawing) recalled better than those who mentally simulated the routes and those who did not rehearse, suggesting that hand movements produced during rehearsal facilitate route learning. Interestingly, participants who gestured the routes in the air or on paper recalled better than those who drew them on paper in both experiments, suggesting that the facilitation effect of co-thought gesture holds for both verbal and nonverbal recall modalities. It is possibly because, co-thought gesture, as a kind of representational action, consolidates spatial sequence better than drawing and thus exerting more powerful influence on spatial representation. PMID:25426624

  17. Facilitating Creativity in Adult Learners

    ERIC Educational Resources Information Center

    Tsai, Kuan Chen

    2013-01-01

    Creativity in education research has received increasing attention, although the major focus of this research has been on children. Despite pleas by several adult educators for promoting creativity, very few studies have focused on adult learners, leaving to it to be explored what approaches are useful for adult educators to facilitate creativity…

  18. SUPERFUND GROUNDWATER ISSUE - FACILITATED TRANSPORT

    EPA Science Inventory

    The Regional Superfund Ground Water Forum is a group of ground-water scientists representing EPA's Regional Superfund Offices, organized to exchange up to date information related to ground-water remediation at Superfund sites. Facilitated transport is an issue identified by the ...

  19. Facilitation of Mourning During Childhood.

    ERIC Educational Resources Information Center

    Kliman, Gilbert; And Others

    This paper discusses case studies of children psychologically disturbed by the death of parents or siblings. Illustrations of mourning facilitation were mainly gathered from 16 orphaned children, ages 3-14. Some techniques used in helping children mourn include: discussing physical details of the illness, discussing previous deaths of animals and…

  20. Social Facilitation of Aiding Responses.

    ERIC Educational Resources Information Center

    Bartell, Patricia; And Others

    Research on individual's response to emergency situations in the presence of others has produced conflicting results. The bystander effect is the label applied to inaction or the unlikelihood of assistance with others present. The social facilitation effect occurs when the presence of others energizes response; strong habit responses are…

  1. Facilitating Facilitators to Facilitate, in Problem or Enquiry Based Learning Sessions

    ERIC Educational Resources Information Center

    Coelho, Catherine

    2014-01-01

    Problem based learning (PBL) has been used in dental education over the past 20 years and uses a patient case scenario to stimulate learning in a small group setting, where a trained facilitator does not teach but guides the group to bring about deep contextualized learning, to be empathetic to each other and to encourage fair and equitable…

  2. Smart pattern recognition

    NASA Astrophysics Data System (ADS)

    Alfalou, A.; Brosseau, C.; Alam, M. S.

    2013-03-01

    The purpose of this paper is to test correlation methods for pattern recognition applications. A broad overview of the main correlation architectures is first given. Many correlation data are compared with those obtained from standard pattern recognition methods. We used our simulations to predict improved decisional performance from correlation methods. More specifically, we are focused on the POF filter and composite filter family. We present an optimized composite correlation filter, called asymmetric segmented phase-only filter (ASPOF) for mobile target recognition applications. The main objective is to find a compromise between the number of references to be merged in the correlation filter and the time needed for making a decision. We suggest an all-numerical implementation of a VanderLugt (VLC) type composite filter. The aim of this all-numerical implementation is to take advantage of the benefits of the correlation methods and make the correlator easily reconfigurable for various scenarios. The use of numerical implementation of the optical Fourier transform improves the decisional performance of the correlator. Further, it renders the correlator less sensitive to the saturation phenomenon caused by the increased number of references used for fabricating the composite filter. Different tests are presented making use of the peak-to-correlation energy criterion and ROC curves. These tests confirm the validity ofour technique. Elderly fall detection and underwater mine detection are two applications which are considered for illustrating the benefits of our approach. The present work is motivated by the need for detailed discussions of the choice of the correlation architecture for these specific applications, pre-processing in the input plane and post processing in the output plane techniques for such analysis.

  3. Counterfactual Thinking Facilitates Behavioral Intentions

    PubMed Central

    Smallman, Rachel; Roese, Neal J.

    2009-01-01

    People often ponder what might have been, and these counterfactual inferences have been linked to behavior regulation. Counterfactuals may enhance performance by either a content-specific pathway (via shift in behavioral intentions) and/or a content-neutral pathway (via mindsets or motivation). Three experiments provided new specification of the content-specific pathway. A sequential priming paradigm revealed that counterfactual judgments facilitated RTs to complete behavioral intention judgments relative to control judgments and to a no-judgment baseline (Experiment 1). This facilitation effect was found only for intention judgments that matched the information content of the counterfactual (Experiment 2) and only for intention judgments as opposed to a different judgment that nevertheless focused on the same information content (Experiment 3). These findings clarify the content-specific pathway by which counterfactuals influence behavior. PMID:20161221

  4. Modulation of Recognition Memory for Emotional Images by Vertical Vection

    PubMed Central

    Väljamäe, Aleksander; Seno, Takeharu

    2016-01-01

    Our previous research showed that vertical vection could modulate human mood. We further examined this possibility by using memory recognition task of positive, negative and neutral emotional images with high and low arousal levels. Those images were remembered accidentally while the participants did visual dummy task, and later presented together with novel images during vertical vection-inducing or neutral visual stimuli. The results showed that downward vection facilitated the recognition of negative images and inhibited the recognition of positive ones. These modulations of incidental memory task provide an additional evidence for vection influence on cognitive and emotional processing, and also provide a new paradigm that can be used in future vection and embodied cognition research. PMID:26869949

  5. Use of flax oil to influence honey bee nestmate recognition.

    PubMed

    Breed, Michael D; Lyon, Cecily A; Sutherland, Anna; Buchwald, Robert

    2012-08-01

    Fatty acids, normally found in comb wax, have a strong influence on nestmate recognition in honey bees, Apis mellifera L. Previous work has shown that bees from different colonies, when treated with 16- or 18-carbon fatty acids, such as oleic, linoleic, or linolenic acids, are much less likely to fight than bees from two colonies when only one of the two is treated. Previous work also shows that the influence of comb wax on recognition has practical applications; transfer of empty comb between colonies, before merger of those colonies, reduces fighting among workers within the merged colony. Flax oil contains many of the same fatty acids as beeswax. Here, we tested the hypothesis that treatment of individual bees with flax oil affects nestmate recognition; the results proved to be consistent with this hypothesis and showed that treated bees from different colonies were less likely to fight than untreated bees. These results suggest that flax oil may be useful in facilitating colony mergers.

  6. [Without reciprocal recognition there is not quality of care].

    PubMed

    Calvo Rigual, Fernando; Costa Alcaraz, Ana M; García-Conde Brú, Javier; Megía Sanz, María Jesús

    2011-10-01

    Understanding the classic doctor-patient relationship has entered a crisis in medicine today. Communication difficulties, underestimation of empathy, or bringing economic criteria are leading to care styles that facilitate the objectification of patients, contempt for doctors, and indifference of both to collective measures of health. Basic principles of this relationship such as quality, justice, patient autonomy and beneficence may appear weak content. We intend to apply the concept of "reciprocal recognition" from philosophy to "recharge" content different aspects of the clinical relationship: a look "inside", dealing with the identity of the protagonists seek to promote it by using reciprocal recognition of both patient and the professional. In one aspect "external", focusing on the quality of care, a key objective of the clinical relationship. With reciprocal recognition, issues of justice and equity are reinforced through public health, building an identity of citizens with rights.

  7. [Comparative studies of face recognition].

    PubMed

    Kawai, Nobuyuki

    2012-07-01

    Every human being is proficient in face recognition. However, the reason for and the manner in which humans have attained such an ability remain unknown. These questions can be best answered-through comparative studies of face recognition in non-human animals. Studies in both primates and non-primates show that not only primates, but also non-primates possess the ability to extract information from their conspecifics and from human experimenters. Neural specialization for face recognition is shared with mammals in distant taxa, suggesting that face recognition evolved earlier than the emergence of mammals. A recent study indicated that a social insect, the golden paper wasp, can distinguish their conspecific faces, whereas a closely related species, which has a less complex social lifestyle with just one queen ruling a nest of underlings, did not show strong face recognition for their conspecifics. Social complexity and the need to differentiate between one another likely led humans to evolve their face recognition abilities.

  8. Genetic specificity of face recognition.

    PubMed

    Shakeshaft, Nicholas G; Plomin, Robert

    2015-10-13

    Specific cognitive abilities in diverse domains are typically found to be highly heritable and substantially correlated with general cognitive ability (g), both phenotypically and genetically. Recent twin studies have found the ability to memorize and recognize faces to be an exception, being similarly heritable but phenotypically substantially uncorrelated both with g and with general object recognition. However, the genetic relationships between face recognition and other abilities (the extent to which they share a common genetic etiology) cannot be determined from phenotypic associations. In this, to our knowledge, first study of the genetic associations between face recognition and other domains, 2,000 18- and 19-year-old United Kingdom twins completed tests assessing their face recognition, object recognition, and general cognitive abilities. Results confirmed the substantial heritability of face recognition (61%), and multivariate genetic analyses found that most of this genetic influence is unique and not shared with other cognitive abilities.

  9. Retina vascular network recognition

    NASA Astrophysics Data System (ADS)

    Tascini, Guido; Passerini, Giorgio; Puliti, Paolo; Zingaretti, Primo

    1993-09-01

    The analysis of morphological and structural modifications of the retina vascular network is an interesting investigation method in the study of diabetes and hypertension. Normally this analysis is carried out by qualitative evaluations, according to standardized criteria, though medical research attaches great importance to quantitative analysis of vessel color, shape and dimensions. The paper describes a system which automatically segments and recognizes the ocular fundus circulation and micro circulation network, and extracts a set of features related to morphometric aspects of vessels. For this class of images the classical segmentation methods seem weak. We propose a computer vision system in which segmentation and recognition phases are strictly connected. The system is hierarchically organized in four modules. Firstly the Image Enhancement Module (IEM) operates a set of custom image enhancements to remove blur and to prepare data for subsequent segmentation and recognition processes. Secondly the Papilla Border Analysis Module (PBAM) automatically recognizes number, position and local diameter of blood vessels departing from optical papilla. Then the Vessel Tracking Module (VTM) analyses vessels comparing the results of body and edge tracking and detects branches and crossings. Finally the Feature Extraction Module evaluates PBAM and VTM output data and extracts some numerical indexes. Used algorithms appear to be robust and have been successfully tested on various ocular fundus images.

  10. Complex Event Recognition Architecture

    NASA Technical Reports Server (NTRS)

    Fitzgerald, William A.; Firby, R. James

    2009-01-01

    Complex Event Recognition Architecture (CERA) is the name of a computational architecture, and software that implements the architecture, for recognizing complex event patterns that may be spread across multiple streams of input data. One of the main components of CERA is an intuitive event pattern language that simplifies what would otherwise be the complex, difficult tasks of creating logical descriptions of combinations of temporal events and defining rules for combining information from different sources over time. In this language, recognition patterns are defined in simple, declarative statements that combine point events from given input streams with those from other streams, using conjunction, disjunction, and negation. Patterns can be built on one another recursively to describe very rich, temporally extended combinations of events. Thereafter, a run-time matching algorithm in CERA efficiently matches these patterns against input data and signals when patterns are recognized. CERA can be used to monitor complex systems and to signal operators or initiate corrective actions when anomalous conditions are recognized. CERA can be run as a stand-alone monitoring system, or it can be integrated into a larger system to automatically trigger responses to changing environments or problematic situations.

  11. Sudden Event Recognition: A Survey

    PubMed Central

    Suriani, Nor Surayahani; Hussain, Aini; Zulkifley, Mohd Asyraf

    2013-01-01

    Event recognition is one of the most active research areas in video surveillance fields. Advancement in event recognition systems mainly aims to provide convenience, safety and an efficient lifestyle for humanity. A precise, accurate and robust approach is necessary to enable event recognition systems to respond to sudden changes in various uncontrolled environments, such as the case of an emergency, physical threat and a fire or bomb alert. The performance of sudden event recognition systems depends heavily on the accuracy of low level processing, like detection, recognition, tracking and machine learning algorithms. This survey aims to detect and characterize a sudden event, which is a subset of an abnormal event in several video surveillance applications. This paper discusses the following in detail: (1) the importance of a sudden event over a general anomalous event; (2) frameworks used in sudden event recognition; (3) the requirements and comparative studies of a sudden event recognition system and (4) various decision-making approaches for sudden event recognition. The advantages and drawbacks of using 3D images from multiple cameras for real-time application are also discussed. The paper concludes with suggestions for future research directions in sudden event recognition. PMID:23921828

  12. Frequency-Based Fingerprint Recognition

    NASA Astrophysics Data System (ADS)

    Aguilar, Gualberto; Sánchez, Gabriel; Toscano, Karina; Pérez, Héctor

    abstract Fingerprint recognition is one of the most popular methods used for identification with greater success degree. Fingerprint has unique characteristics called minutiae, which are points where a curve track ends, intersects, or branches off. In this chapter a fingerprint recognition method is proposed in which a combination of Fast Fourier Transform (FFT) and Gabor filters is used for image enhancement. A novel recognition stage using local features for recognition is also proposed. Also a verification stage is introduced to be used when the system output has more than one person.

  13. [Faces affect recognition in schizophrenia].

    PubMed

    Prochwicz, Katarzyna; Rózycka, Jagoda

    2012-01-01

    Clinical observations and the results of many experimental researches indicate that individuals suffering from schizophrenia reveal difficulties in the recognition of emotional states experienced by other people; however the causes and the range of these problems have not been clearly described. Despite early research results confirming that difficulties in emotion recognition are related only to negative emotions, the results of the researches conducted over the lat 30 years indicate that emotion recognition problems are a manifestation of a general cognitive deficit, and they do not concern specific emotions. The article contains a review of the research on face affect recognition in schizophrenia. It discusses the causes of these difficulties, the differences in the accuracy of the recognition of specific emotions, the relationship between the symptoms of schizophrenia and the severity of problems with face perception, and the types of cognitive processes which influence the disturbances in face affect recognition. Particular attention was paid to the methodology of the research on face affect recognition, including the methods used in control tasks relying on the identification of neutral faces designed to assess the range of deficit underlying the face affect recognition problems. The analysis of methods used in particular researches revealed some weaknesses. The article also deals with the question of the possibilities of improving the ability to recognise the emotions, and briefly discusses the efficiency of emotion recognition training programs designed for patients suffering from schizophrenia.

  14. Molecular basis of factor IXa recognition by heparin-activated antithrombin revealed by a 1.7-A structure of the ternary complex.

    PubMed

    Johnson, Daniel J D; Langdown, Jonathan; Huntington, James A

    2010-01-12

    Factor (f) IXa is a critical enzyme for the formation of stable blood clots, and its deficiency results in hemophilia. The enzyme functions at the confluence of the intrinsic and extrinsic pathways by binding to fVIIIa and rapidly generating fXa. In spite of its importance, little is known about how fIXa recognizes its cofactor, its substrate, or its only known inhibitor, antithrombin (AT). However, it is clear that fIXa requires extensive exosite interactions to present substrates for efficient cleavage. Here we describe the 1.7-A crystal structure of fIXa in its recognition (Michaelis) complex with heparin-activated AT. It represents the highest resolution structure of both proteins and allows us to address several outstanding issues. The structure reveals why the heparin-induced conformational change in AT is required to permit simultaneous active-site and exosite interactions with fIXa and the nature of these interactions. The reactive center loop of AT has evolved to specifically inhibit fIXa, with a P2 Gly so as not to clash with Tyr99 on fIXa, a P4 Ile to fit snugly into the S4 pocket, and a C-terminal extension to exploit a unique wall-like feature of the active-site cleft. Arg150 is at the center of the exosite interface, interacting with AT residues on beta-sheet C. A surprising crystal contact is observed between the heparin pentasaccharide and fIXa, revealing a plausible mode of binding that would allow longer heparin chains to bridge the complex. PMID:20080729

  15. How We Think and Talk about Facilitation

    ERIC Educational Resources Information Center

    Kato, Fumitoshi

    2010-01-01

    Over the past few years, the notion of "facilitation" has been increasingly gaining attention and acceptance in Japan, especially in the context of education and training. Today, Japanese educators think and talk about facilitation, even if it is not yet clear what facilitation is. Interestingly enough, the term "facilitation" does not exist in…

  16. Breastfeeding experience differentially impacts recognition of happiness and anger in mothers.

    PubMed

    Krol, Kathleen M; Kamboj, Sunjeev K; Curran, H Valerie; Grossmann, Tobias

    2014-11-12

    Breastfeeding is a dynamic biological and social process based on hormonal regulation involving oxytocin. While there is much work on the role of breastfeeding in infant development and on the role of oxytocin in socio-emotional functioning in adults, little is known about how breastfeeding impacts emotion perception during motherhood. We therefore examined whether breastfeeding influences emotion recognition in mothers. Using a dynamic emotion recognition task, we found that longer durations of exclusive breastfeeding were associated with faster recognition of happiness, providing evidence for a facilitation of processing positive facial expressions. In addition, we found that greater amounts of breastfed meals per day were associated with slower recognition of anger. Our findings are in line with current views of oxytocin function and support accounts that view maternal behaviour as tuned to prosocial responsiveness, by showing that vital elements of maternal care can facilitate the rapid responding to affiliative stimuli by reducing importance of threatening stimuli.

  17. Improving robustness of speech recognition systems

    NASA Astrophysics Data System (ADS)

    Mitra, Vikramjit

    2010-11-01

    Current Automatic Speech Recognition (ASR) systems fail to perform nearly as good as human speech recognition performance due to their lack of robustness against speech variability and noise contamination. The goal of this dissertation is to investigate these critical robustness issues, put forth different ways to address them and finally present an ASR architecture based upon these robustness criteria. Acoustic variations adversely affect the performance of current phone-based ASR systems, in which speech is modeled as 'beads-on-a-string', where the beads are the individual phone units. While phone units are distinctive in cognitive domain, they are varying in the physical domain and their variation occurs due to a combination of factors including speech style, speaking rate etc.; a phenomenon commonly known as 'coarticulation'. Traditional ASR systems address such coarticulatory variations by using contextualized phone-units such as triphones. Articulatory phonology accounts for coarticulatory variations by modeling speech as a constellation of constricting actions known as articulatory gestures. In such a framework, speech variations such as coarticulation and lenition are accounted for by gestural overlap in time and gestural reduction in space. To realize a gesture-based ASR system, articulatory gestures have to be inferred from the acoustic signal. At the initial stage of this research an initial study was performed using synthetically generated speech to obtain a proof-of-concept that articulatory gestures can indeed be recognized from the speech signal. It was observed that having vocal tract constriction trajectories (TVs) as intermediate representation facilitated the gesture recognition task from the speech signal. Presently no natural speech database contains articulatory gesture annotation; hence an automated iterative time-warping architecture is proposed that can annotate any natural speech database with articulatory gestures and TVs. Two natural

  18. Stochastic facilitation in the brain?

    NASA Astrophysics Data System (ADS)

    Ward, Lawrence M.; Greenwood, Priscilla E.

    2016-05-01

    We describe the context for three unsolved problems of noise in the brain as well as provide some new results relevant to one of them. The problems are: are neural oscillations better described as noisy limit cycles or as noise-driven quasicycles, does noise facilitate synchronization and information transmission in the brain, and do noise-driven spatial patterns (quasipatterns) coexist with noise-driven quasicycles in the brain? We provide a few new results indicating that, in models at least, spatial quasipatterns of quasicycles can occur, and resemble patterns observed in other areas, such as predator-prey systems and chemical reactions.

  19. The Legal Recognition of Sign Languages

    ERIC Educational Resources Information Center

    De Meulder, Maartje

    2015-01-01

    This article provides an analytical overview of the different types of explicit legal recognition of sign languages. Five categories are distinguished: constitutional recognition, recognition by means of general language legislation, recognition by means of a sign language law or act, recognition by means of a sign language law or act including…

  20. Teaching and the Dialectic of Recognition

    ERIC Educational Resources Information Center

    Huttunen, Rauno; Heikkinen, Hannu L. T.

    2004-01-01

    In this article, the processes of recognition within education are discussed. Frequently, recognition is reduced to polite behaviour or etiquette. Another narrow view of recognition is, behaviouristically speaking, to regard it as mere feedback. We claim that authentic recognition is a different matter. Receiving recognition, as Charles Taylor has…

  1. Chemical recognition software

    SciTech Connect

    Wagner, J.S.; Trahan, M.W.; Nelson, W.E.; Hargis, P.H. Jr.; Tisone, G.C.

    1994-06-01

    We have developed a capability to make real time concentration measurements of individual chemicals in a complex mixture using a multispectral laser remote sensing system. Our chemical recognition and analysis software consists of three parts: (1) a rigorous multivariate analysis package for quantitative concentration and uncertainty estimates, (2) a genetic optimizer which customizes and tailors the multivariate algorithm for a particular application, and (3) an intelligent neural net chemical filter which pre-selects from the chemical database to find the appropriate candidate chemicals for quantitative analyses by the multivariate algorithms, as well as providing a quick-look concentration estimate and consistency check. Detailed simulations using both laboratory fluorescence data and computer synthesized spectra indicate that our software can make accurate concentration estimates from complex multicomponent mixtures, even when the mixture is noisy and contaminated with unknowns.

  2. Chemical recognition software

    SciTech Connect

    Wagner, J.S.; Trahan, M.W.; Nelson, W.E.; Hargis, P.J. Jr.; Tisone, G.C.

    1994-12-01

    We have developed a capability to make real time concentration measurements of individual chemicals in a complex mixture using a multispectral laser remote sensing system. Our chemical recognition and analysis software consists of three parts: (1) a rigorous multivariate analysis package for quantitative concentration and uncertainty estimates, (2) a genetic optimizer which customizes and tailors the multivariate algorithm for a particular application, and (3) an intelligent neural net chemical filter which pre-selects from the chemical database to find the appropriate candidate chemicals for quantitative analyses by the multivariate algorithms, as well as providing a quick-look concentration estimate and consistency check. Detailed simulations using both laboratory fluorescence data and computer synthesized spectra indicate that our software can make accurate concentration estimates from complex multicomponent mixtures. even when the mixture is noisy and contaminated with unknowns.

  3. Early recognition of speech

    PubMed Central

    Remez, Robert E; Thomas, Emily F

    2013-01-01

    Classic research on the perception of speech sought to identify minimal acoustic correlates of each consonant and vowel. In explaining perception, this view designated momentary components of an acoustic spectrum as cues to the recognition of elementary phonemes. This conceptualization of speech perception is untenable given the findings of phonetic sensitivity to modulation independent of the acoustic and auditory form of the carrier. The empirical key is provided by studies of the perceptual organization of speech, a low-level integrative function that finds and follows the sensory effects of speech amid concurrent events. These projects have shown that the perceptual organization of speech is keyed to modulation; fast; unlearned; nonsymbolic; indifferent to short-term auditory properties; and organization requires attention. The ineluctably multisensory nature of speech perception also imposes conditions that distinguish language among cognitive systems. WIREs Cogn Sci 2013, 4:213–223. doi: 10.1002/wcs.1213 PMID:23926454

  4. Recognition Using Hybrid Classifiers.

    PubMed

    Osadchy, Margarita; Keren, Daniel; Raviv, Dolev

    2016-04-01

    A canonical problem in computer vision is category recognition (e.g., find all instances of human faces, cars etc., in an image). Typically, the input for training a binary classifier is a relatively small sample of positive examples, and a huge sample of negative examples, which can be very diverse, consisting of images from a large number of categories. The difficulty of the problem sharply increases with the dimension and size of the negative example set. We propose to alleviate this problem by applying a "hybrid" classifier, which replaces the negative samples by a prior, and then finds a hyperplane which separates the positive samples from this prior. The method is extended to kernel space and to an ensemble-based approach. The resulting binary classifiers achieve an identical or better classification rate than SVM, while requiring far smaller memory and lower computational complexity to train and apply.

  5. TOPICAL REVIEW: Recognition tunneling

    NASA Astrophysics Data System (ADS)

    Lindsay, Stuart; He, Jin; Sankey, Otto; Hapala, Prokop; Jelinek, Pavel; Zhang, Peiming; Chang, Shuai; Huang, Shuo

    2010-07-01

    Single molecules in a tunnel junction can now be interrogated reliably using chemically functionalized electrodes. Monitoring stochastic bonding fluctuations between a ligand bound to one electrode and its target bound to a second electrode ('tethered molecule-pair' configuration) gives insight into the nature of the intermolecular bonding at a single molecule-pair level, and defines the requirements for reproducible tunneling data. Simulations show that there is an instability in the tunnel gap at large currents, and this results in a multiplicity of contacts with a corresponding spread in the measured currents. At small currents (i.e. large gaps) the gap is stable, and functionalizing a pair of electrodes with recognition reagents (the 'free-analyte' configuration) can generate a distinct tunneling signal when an analyte molecule is trapped in the gap. This opens up a new interface between chemistry and electronics with immediate implications for rapid sequencing of single DNA molecules.

  6. Automatic speech recognition

    NASA Astrophysics Data System (ADS)

    Espy-Wilson, Carol

    2005-04-01

    Great strides have been made in the development of automatic speech recognition (ASR) technology over the past thirty years. Most of this effort has been centered around the extension and improvement of Hidden Markov Model (HMM) approaches to ASR. Current commercially-available and industry systems based on HMMs can perform well for certain situational tasks that restrict variability such as phone dialing or limited voice commands. However, the holy grail of ASR systems is performance comparable to humans-in other words, the ability to automatically transcribe unrestricted conversational speech spoken by an infinite number of speakers under varying acoustic environments. This goal is far from being reached. Key to the success of ASR is effective modeling of variability in the speech signal. This tutorial will review the basics of ASR and the various ways in which our current knowledge of speech production, speech perception and prosody can be exploited to improve robustness at every level of the system.

  7. Dynamics of alpha oscillations elucidate facial affect recognition in schizophrenia.

    PubMed

    Popov, Tzvetan G; Rockstroh, Brigitte S; Popova, Petia; Carolus, Almut M; Miller, Gregory A

    2014-03-01

    Impaired facial affect recognition is characteristic of schizophrenia and has been related to impaired social function, but the relevant neural mechanisms have not been fully identified. The present study sought to identify the role of oscillatory alpha activity in that deficit during the process of facial emotion recognition. Neuromagnetic brain activity was monitored while 44 schizophrenia patients and 44 healthy controls viewed 5-s videos showing human faces gradually changing from neutral to fearful or happy expressions or from the neutral face of one poser to the neutral face of another. Recognition performance was determined separately by self-report. Relative to prestimulus baseline, controls exhibited a 10- to 15-Hz power increase prior to full recognition and a 10- to 15-Hz power decrease during the postrecognition phase. These results support recent proposals about the function of alpha-band oscillations in normal stimulus evaluation. The patients failed to show this sequence of alpha power increase and decrease and also showed low 10- to 15-Hz power and high 10- to 15-Hz connectivity during the prestimulus baseline. In light of the proposal that a combination of alpha power increase and functional disconnection facilitates information intake and processing, the finding of an abnormal association of low baseline alpha power and high connectivity in schizophrenia suggests a state of impaired readiness that fosters abnormal dynamics during facial affect recognition.

  8. Computer image processing and recognition

    NASA Technical Reports Server (NTRS)

    Hall, E. L.

    1979-01-01

    A systematic introduction to the concepts and techniques of computer image processing and recognition is presented. Consideration is given to such topics as image formation and perception; computer representation of images; image enhancement and restoration; reconstruction from projections; digital television, encoding, and data compression; scene understanding; scene matching and recognition; and processing techniques for linear systems.

  9. Methods of Teaching Speech Recognition

    ERIC Educational Resources Information Center

    Rader, Martha H.; Bailey, Glenn A.

    2010-01-01

    Objective: This article introduces the history and development of speech recognition, addresses its role in the business curriculum, outlines related national and state standards, describes instructional strategies, and discusses the assessment of student achievement in speech recognition classes. Methods: Research methods included a synthesis of…

  10. Word Recognition and Critical Reading.

    ERIC Educational Resources Information Center

    Groff, Patrick

    1991-01-01

    This article discusses the distinctions between literal and critical reading and explains the role that word recognition ability plays in critical reading behavior. It concludes that correct word recognition provides the raw material on which higher order critical reading is based. (DB)

  11. Recognition without Rewards: Building Connections.

    ERIC Educational Resources Information Center

    Cameron, Caren; Tate, Betty; MacNaughton, Daphne; Politano, Colleen

    Noting that the use of rewards in the form of stickers, trophies, prizes, points, tokens, and grades is commonplace in elementary education today, this book explores the differences between rewards and recognition and shows how teachers can build student confidence, motivate learning, and develop skills for lifelong learning through recognition.…

  12. Positive Emotion Facilitates Audiovisual Binding

    PubMed Central

    Kitamura, Miho S.; Watanabe, Katsumi; Kitagawa, Norimichi

    2016-01-01

    It has been shown that positive emotions can facilitate integrative and associative information processing in cognitive functions. The present study examined whether emotions in observers can also enhance perceptual integrative processes. We tested 125 participants in total for revealing the effects of emotional states and traits in observers on the multisensory binding between auditory and visual signals. Participants in Experiment 1 observed two identical visual disks moving toward each other, coinciding, and moving away, presented with a brief sound. We found that for participants with lower depressive tendency, induced happy moods increased the width of the temporal binding window of the sound-induced bounce percept in the stream/bounce display, while no effect was found for the participants with higher depressive tendency. In contrast, no effect of mood was observed for a simple audiovisual simultaneity discrimination task in Experiment 2. These results provide the first empirical evidence of a dependency of multisensory binding upon emotional states and traits, revealing that positive emotions can facilitate the multisensory binding processes at a perceptual level. PMID:26834585

  13. Face recognition performance with superresolution.

    PubMed

    Hu, Shuowen; Maschal, Robert; Young, S Susan; Hong, Tsai Hong; Phillips, P Jonathon

    2012-06-20

    With the prevalence of surveillance systems, face recognition is crucial to aiding the law enforcement community and homeland security in identifying suspects and suspicious individuals on watch lists. However, face recognition performance is severely affected by the low face resolution of individuals in typical surveillance footage, oftentimes due to the distance of individuals from the cameras as well as the small pixel count of low-cost surveillance systems. Superresolution image reconstruction has the potential to improve face recognition performance by using a sequence of low-resolution images of an individual's face in the same pose to reconstruct a more detailed high-resolution facial image. This work conducts an extensive performance evaluation of superresolution for a face recognition algorithm using a methodology and experimental setup consistent with real world settings at multiple subject-to-camera distances. Results show that superresolution image reconstruction improves face recognition performance considerably at the examined midrange and close range. PMID:22722306

  14. Face recognition performance with superresolution.

    PubMed

    Hu, Shuowen; Maschal, Robert; Young, S Susan; Hong, Tsai Hong; Phillips, P Jonathon

    2012-06-20

    With the prevalence of surveillance systems, face recognition is crucial to aiding the law enforcement community and homeland security in identifying suspects and suspicious individuals on watch lists. However, face recognition performance is severely affected by the low face resolution of individuals in typical surveillance footage, oftentimes due to the distance of individuals from the cameras as well as the small pixel count of low-cost surveillance systems. Superresolution image reconstruction has the potential to improve face recognition performance by using a sequence of low-resolution images of an individual's face in the same pose to reconstruct a more detailed high-resolution facial image. This work conducts an extensive performance evaluation of superresolution for a face recognition algorithm using a methodology and experimental setup consistent with real world settings at multiple subject-to-camera distances. Results show that superresolution image reconstruction improves face recognition performance considerably at the examined midrange and close range.

  15. Emotional valence of stimuli modulates false recognition: Using a modified version of the simplified conjoint recognition paradigm.

    PubMed

    Gong, Xianmin; Xiao, Hongrui; Wang, Dahua

    2016-11-01

    False recognition results from the interplay of multiple cognitive processes, including verbatim memory, gist memory, phantom recollection, and response bias. In the current study, we modified the simplified Conjoint Recognition (CR) paradigm to investigate the way in which the valence of emotional stimuli affects the cognitive process and behavioral outcome of false recognition. In Study 1, we examined the applicability of the modification to the simplified CR paradigm and model. Twenty-six undergraduate students (13 females, aged 21.00±2.30years) learned and recognized both the large and small categories of photo objects. The applicability of the paradigm and model was confirmed by a fair goodness-of-fit of the model to the observational data and by their competence in detecting the memory differences between the large- and small-category conditions. In Study 2, we recruited another sample of 29 undergraduate students (14 females, aged 22.60±2.74years) to learn and recognize the categories of photo objects that were emotionally provocative. The results showed that negative valence increased false recognition, particularly the rate of false "remember" responses, by facilitating phantom recollection; positive valence did not influence false recognition significantly though enhanced gist processing. PMID:27592144

  16. Speech Recognition: How Do We Teach It?

    ERIC Educational Resources Information Center

    Barksdale, Karl

    2002-01-01

    States that growing use of speech recognition software has made voice writing an essential computer skill. Describes how to present the topic, develop basic speech recognition skills, and teach speech recognition outlining, writing, proofreading, and editing. (Contains 14 references.) (SK)

  17. Exploring the role of lexical stress in lexical recognition.

    PubMed

    van Donselaar, Wilma; Koster, Mariëtte; Cutler, Anne

    2005-02-01

    Three cross-modal priming experiments examined the role of suprasegmental information in the processing of spoken words. All primes consisted of truncated spoken Dutch words. Recognition of visually presented word targets was facilitated by prior auditory presentation of the first two syllables of the same words as primes, but only if they were appropriately stressed (e.g., OKTOBER preceded by okTO-); inappropriate stress, compatible with another word (e.g., OKTOBER preceded by OCto-, the beginning of octopus), produced inhibition. Monosyllabic fragments (e.g., OC-) also produced facilitation when appropriately stressed; if inappropriately stressed, they produced neither facilitation nor inhibition. The bisyllabic fragments that were compatible with only one word produced facilitation to semantically associated words, but inappropriate stress caused no inhibition of associates. The results are explained within a model of spoken-word recognition involving competition between simultaneously activated phonological representations followed by activation of separate conceptual representations for strongly supported lexical candidates; at the level of the phonological representations, activation is modulated by both segmental and suprasegmental information.

  18. Tobacco use prevention and health facilitator effectiveness.

    PubMed

    Young, R L; Elder, J P; Green, M; de Moor, C; Wildey, M B

    1988-11-01

    Tobacco prevention programs often use peers to teach refusal skills to other adolescents. College undergraduate health facilitators delivered a tobacco prevention intervention to sixth and seventh grade students in six schools. Outside observers evaluated facilitators in seven categories: being prepared, maintaining class control, keeping students' attention, encouraging participation, communication, relating to students, and working well in a team. Facilitators were rated highly in all categories. Higher rated health facilitators had more effect in reducing tobacco use than poorly rated facilitators. Facilitators who worked well in a team, related well to students, and were well-prepared were especially effective in positively influencing program outcomes.

  19. The Influence of Facilitator and Facilitation Characteristics on Participants' Ratings of Stepfamily Education

    ERIC Educational Resources Information Center

    Higginbotham, Brian J.; Myler, Cory

    2010-01-01

    We examine the relative importance of facilitator and facilitation characteristics on participant ratings of a stepfamily education program. Data from 48 facilitators and 598 participants suggest that quality facilitation is more meaningful to participants than whether facilitators have comparable demographic characteristics or life experiences.…

  20. Guanidinium Pairing Facilitates Membrane Translocation.

    PubMed

    Allolio, Christoph; Baxova, Katarina; Vazdar, Mario; Jungwirth, Pavel

    2016-01-14

    Ab initio free energy calculations of guanidinium pairing in aqueous solution confirm the counterintuitive conjecture that the like-charge ion pair is thermodynamically stable. Transferring the guanidinium pair to the inside of a POPC lipid bilayer, like-charge ion pairing is found to occur also inside the membrane defect. It is found to contribute to the nonadditivity of ion transfer, thereby facilitating the presence of ions inside the bilayer. The effect is quantified by free energy decomposition and comparison with ammonium ions, which do not form a stable pair. The presence of two charges inside the center of the bilayer leads to the formation of a pore. Potential consequences for cell penetrating peptides and ion conduction are drawn.

  1. Facilitating submetering implementation. Final report

    SciTech Connect

    Bowers, M.A.

    1996-05-01

    Residential submetering is the measurement and billing of electric use in individual apartments in master-metered buildings. In master-metered building situations, residents do not bear electricity costs in proportion to consumption levels. As a result, studies have confirmed that residents in master-metered buildings tend to consume more electricity than residents with individual apartment metering, and have established electrical submetering as an effective energy conservation measure. The New York State Energy Research & Development Authority (NYSERDA) has commissioned a project called Facilitating Submetering Implementation to identify and analyze barriers to the implementation of residential electrical submetering in New York and to formulate recommendations that would facilitate the removal of these barriers, streamlining the process. Experienced professionals in the technical, legal, regulatory, analytical, financial, and other aspects of submetering were retained to interview key interested parties and conduct public forums. This and other data were then analyzed to ascertain the barriers to submetering and develop recommendations designed to reduce or eliminate these barriers. The key barriers to submetering implementation were found to be the Public Service Commission (PSC) requirement for a vote of a majority of shareholders (for coops and condos) and the high initial cost that cannot easily be recouped by owners of both rental and shareholder-owned buildings. The key recommendations are to repeal the voting requirement, maintain the utility incentives, adopt a uniform dispute resolution mechanism, and increase awareness through an Ad-hoc Submetering Committee and supporting educational materials. Other funding sources not fully available can also be made available with regulatory agency support.

  2. Accuracy enhanced thermal face recognition

    NASA Astrophysics Data System (ADS)

    Lin, Chun-Fu; Lin, Sheng-Fuu

    2013-11-01

    Human face recognition has been generally researched for the last three decades. Face recognition with thermal image has begun to attract significant attention gradually since illumination of environment would not affect the recognition performance. However, the recognition performance of traditional thermal face recognizer is still insufficient in practical application. This study presents a novel thermal face recognizer employing not only thermal features but also critical facial geometric features which would not be influenced by hair style to improve the recognition performance. A three-layer back-propagation feed-forward neural network is applied as the classifier. Traditional thermal face recognizers only use the indirect information of the topography of blood vessels like thermogram as features. To overcome this limitation, the proposed thermal face recognizer can use not only the indirect information but also the direct information of the topography of blood vessels which is unique for every human. Moreover, the recognition performance of the proposed thermal features would not decrease even if the hair of frontal bone varies, the eye blinks or the nose breathes. Experimental results show that the proposed features are significantly more effective than traditional thermal features and the recognition performance of thermal face recognizer is improved.

  3. Brownian dynamics simulations of the recognition of the scorpion toxin maurotoxin with the voltage-gated potassium ion channels.

    PubMed Central

    Fu, Wei; Cui, Meng; Briggs, James M; Huang, Xiaoqin; Xiong, Bing; Zhang, Yingmin; Luo, Xiaomin; Shen, Jianhua; Ji, Ruyun; Jiang, Hualiang; Chen, Kaixian

    2002-01-01

    The recognition of the scorpion toxin maurotoxin (MTX) by the voltage-gated potassium (Kv1) channels, Kv1.1, Kv1.2, and Kv1.3, has been studied by means of Brownian dynamics (BD) simulations. All of the 35 available structures of MTX in the Protein Data Bank (http://www.rcsb.org/pdb) determined by nuclear magnetic resonance were considered during the simulations, which indicated that the conformation of MTX significantly affected both the recognition and the binding between MTX and the Kv1 channels. Comparing the top five highest-frequency structures of MTX binding to the Kv1 channels, we found that the Kv1.2 channel, with the highest docking frequencies and the lowest electrostatic interaction energies, was the most favorable for MTX binding, whereas Kv1.1 was intermediate, and Kv1.3 was the least favorable one. Among the 35 structures of MTX, the 10th structure docked into the binding site of the Kv1.2 channel with the highest probability and the most favorable electrostatic interactions. From the MTX-Kv1.2 binding model, we identified the critical residues for the recognition of these two proteins through triplet contact analyses. MTX locates around the extracellular mouth of the Kv1 channels, making contacts with its beta-sheets. Lys23, a conserved amino acid in the scorpion toxins, protrudes into the pore of the Kv1.2 channel and forms two hydrogen bonds with the conserved residues Gly401(D) and Tyr400(C) and one hydrophobic contact with Gly401(C) of the Kv1.2 channel. The critical triplet contacts for recognition between MTX and the Kv1.2 channel are Lys23(MTX)-Asp402(C)(Kv1), Lys27(MTX)-Asp378(D)(Kv1), and Lys30(MTX)-Asp402(A)(Kv1). In addition, six hydrogen-bonding interactions are formed between residues Lys23, Lys27, Lys30, and Tyr32 of MTX and residues Gly401, Tyr400, Asp402, Asp378, and Thr406 of Kv1.2. Many of them are formed by side chains of residues of MTX and backbone atoms of the Kv1.2 channel. Five hydrophobic contacts exist between residues Pro

  4. Macromolecular recognition: Recognition of polymer side chains by cyclodextrin

    NASA Astrophysics Data System (ADS)

    Hashidzume, Akihito; Harada, Akira

    2015-12-01

    The interaction of cyclodextrins (CD) with water soluble polymers possessing guest residues has been investigated as model systems in biological molecular recognition. The selectivity of interaction of CD with polymer-carrying guest residues is controlled by polymer chains, i.e., the steric effect of polymer main chain, the conformational effect of polymer main chain, and multi-site interaction. Macroscopic assemblies have been also realized based on molecular recognition using polyacrylamide-based gels possessing CD and guest residues.

  5. Hydrophobic blocks facilitate lipid compatibility and translocon recognition of transmembrane protein sequences.

    PubMed

    Stone, Tracy A; Schiller, Nina; von Heijne, Gunnar; Deber, Charles M

    2015-02-24

    Biophysical hydrophobicity scales suggest that partitioning of a protein segment from an aqueous phase into a membrane is governed by its perceived segmental hydrophobicity but do not establish specifically (i) how the segment is identified in vivo for translocon-mediated insertion or (ii) whether the destination lipid bilayer is biochemically receptive to the inserted sequence. To examine the congruence between these dual requirements, we designed and synthesized a library of Lys-tagged peptides of a core length sufficient to span a bilayer but with varying patterns of sequence, each composed of nine Leu residues, nine Ser residues, and one (central) Trp residue. We found that peptides containing contiguous Leu residues (Leu-block peptides, e.g., LLLLLLLLLWSSSSSSSSS), in comparison to those containing discontinuous stretches of Leu residues (non-Leu-block peptides, e.g., SLSLLSLSSWSLLSLSLLS), displayed greater helicity (circular dichroism spectroscopy), traveled slower during sodium dodecyl sulfate-polyacrylamide gel electrophoresis, had longer reverse phase high-performance liquid chromatography retention times on a C-18 column, and were helical when reconstituted into 1-palmitoyl-2-oleoylglycero-3-phosphocholine liposomes, each observation indicating superior lipid compatibility when a Leu-block is present. These parameters were largely paralleled in a biological membrane insertion assay using microsomal membranes from dog pancreas endoplasmic reticulum, where we found only the Leu-block sequences successfully inserted; intriguingly, an amphipathic peptide (SLLSSLLSSWLLSSLLSSL; Leu face, Ser face) with biophysical properties similar to those of Leu-block peptides failed to insert. Our overall results identify local sequence lipid compatibility rather than average hydrophobicity as a principal determinant of transmembrane segment potential, while demonstrating that further subtleties of hydrophobic and helical patterning, such as circumferential hydrophobicity in Leu-block segments, promote translocon-mediated insertion. PMID:25635746

  6. Incorporation of radio frequency identification tag in dentures to facilitate recognition and forensic human identification.

    PubMed

    Nuzzolese, E; Marcario, V; Di Vella, G

    2010-01-01

    Forensic identification using odontology is based on the comparison of ante-mortem and post mortem dental records. The insertion of a radio frequency identification (RFId) tag into dentures could be used as an aid to identify decomposed bodies, by storing personal identification data in a small transponder that can be radio-transmitted to a reader connected to a computer. A small passive, 12 x 2,1 mm, read-only RFId-tag was incorporated into the manufacture of three trial complete upper dentures and tested for a signal. The aim of this article is to demonstrate the feasibility of manufacturing such a dental prosthesis, the technical protocols for its implantation in the denture resin and its working principles. Future research and tests are required in order to verify human compatibility of the tagged denture and also to evaluate any potential deterioration in strength when subjected to high temperatures, or for damage resulting from everyday wear and tear. It should also be able to withstand the extreme conditions resulting from major accidents or mass disasters and procedures used to perform a forensic identification. PMID:20657641

  7. Incorporation of Radio Frequency Identification Tag in Dentures to Facilitate Recognition and Forensic Human Identification

    PubMed Central

    Nuzzolese, E; Marcario, V; Di Vella, G

    2010-01-01

    Forensic identification using odontology is based on the comparison of ante-mortem and post mortem dental records. The insertion of a radio frequency identification (RFId) tag into dentures could be used as an aid to identify decomposed bodies, by storing personal identification data in a small transponder that can be radio-transmitted to a reader connected to a computer. A small passive, 12 x 2,1 mm, read-only RFId-tag was incorporated into the manufacture of three trial complete upper dentures and tested for a signal. The aim of this article is to demonstrate the feasibility of manufacturing such a dental prosthesis, the technical protocols for its implantation in the denture resin and its working principles. Future research and tests are required in order to verify human compatibility of the tagged denture and also to evaluate any potential deterioration in strength when subjected to high temperatures, or for damage resulting from everyday wear and tear. It should also be able to withstand the extreme conditions resulting from major accidents or mass disasters and procedures used to perform a forensic identification. PMID:20657641

  8. Hydrophobic Blocks Facilitate Lipid Compatibility and Translocon Recognition of Transmembrane Protein Sequences

    PubMed Central

    2016-01-01

    Biophysical hydrophobicity scales suggest that partitioning of a protein segment from an aqueous phase into a membrane is governed by its perceived segmental hydrophobicity but do not establish specifically (i) how the segment is identified in vivo for translocon-mediated insertion or (ii) whether the destination lipid bilayer is biochemically receptive to the inserted sequence. To examine the congruence between these dual requirements, we designed and synthesized a library of Lys-tagged peptides of a core length sufficient to span a bilayer but with varying patterns of sequence, each composed of nine Leu residues, nine Ser residues, and one (central) Trp residue. We found that peptides containing contiguous Leu residues (Leu-block peptides, e.g., LLLLLLLLLWSSSSSSSSS), in comparison to those containing discontinuous stretches of Leu residues (non-Leu-block peptides, e.g., SLSLLSLSSWSLLSLSLLS), displayed greater helicity (circular dichroism spectroscopy), traveled slower during sodium dodecyl sulfate–polyacrylamide gel electrophoresis, had longer reverse phase high-performance liquid chromatography retention times on a C-18 column, and were helical when reconstituted into 1-palmitoyl-2-oleoylglycero-3-phosphocholine liposomes, each observation indicating superior lipid compatibility when a Leu-block is present. These parameters were largely paralleled in a biological membrane insertion assay using microsomal membranes from dog pancreas endoplasmic reticulum, where we found only the Leu-block sequences successfully inserted; intriguingly, an amphipathic peptide (SLLSSLLSSWLLSSLLSSL; Leu face, Ser face) with biophysical properties similar to those of Leu-block peptides failed to insert. Our overall results identify local sequence lipid compatibility rather than average hydrophobicity as a principal determinant of transmembrane segment potential, while demonstrating that further subtleties of hydrophobic and helical patterning, such as circumferential hydrophobicity in Leu-block segments, promote translocon-mediated insertion. PMID:25635746

  9. Crystal structure of CD59: implications for molecular recognition of the complement proteins C8 and C9 in the membrane-attack complex.

    PubMed

    Huang, Yuxiang; Fedarovich, Alena; Tomlinson, Stephen; Davies, Christopher

    2007-06-01

    Human CD59 is a small membrane-bound glycoprotein that functions as an inhibitor of the membrane-attack complex (MAC) of the complement system by binding the complement proteins C8 and C9. The crystal structure of a soluble construct of CD59 has been determined to 2.1 A resolution. When compared with previous models of CD59 determined using NMR, some interesting differences are noted, including the position of helix alpha1, which contributes to the binding surface for C8 and C9. Interestingly, the crystal structure superimposes more closely with an updated NMR model of CD59 that was produced using Monte Carlo minimization, including helix alpha1. Mapping of mutations associated with enhanced or lowered inhibitory function of CD59 show the binding region to be located in a crevice between alpha1 and a three-stranded beta-sheet, as has been identified previously. Residues in the core of this region are well ordered in the electron density, in part owing to a network of stabilizing covalent and noncovalent interactions, and manifest an interesting 'striped' distribution of hydrophobic and basic residues. Docking of the same peptide that was modeled previously into the NMR structure shows that Arg55, which has been postulated to exist in 'open' and 'closed' positions, is intermediate in position between these two and is well placed to contact the peptide. Further clues regarding how CD59 interacts with small peptides arise from the crystal packing of this structure, which shows that a symmetry-related loop comprising residues 20-24 occupies a spatially similar position to the modeled peptide. This higher resolution structure of CD59 will facilitate a more precise dissection of its interactions with C8 and C9 and thus increase the likelihood of designing enhanced CD59-based therapeutics. PMID:17505110

  10. Evaluation of the Facilitated Communication Pilot

    ERIC Educational Resources Information Center

    Cooper-Martin, Elizabeth

    2014-01-01

    The Office of Special Education and Student Services asked the Office of Shared Accountability to evaluate the "Facilitated Communication Pilot." In facilitated communication (FC), people with communication impairments express themselves by typing with the aid of a communication partner, called a facilitator, who provides physical (and…

  11. An experimental analysis of facilitated communication.

    PubMed Central

    Montee, B B; Miltenberger, R G; Wittrock, D; Watkins, N; Rheinberger, A; Stackhaus, J

    1995-01-01

    We evaluated the authorship of messages produced through facilitated communication by 7 adults with moderate or severe mental retardation and their facilitators. The clients had been reported to be communicating fluently through facilitated communication. We controlled the facilitators' access to information to be communicated in two evaluation formats, naming pictures and describing activities. In both formats we conducted three conditions: (a) the facilitator and client had access to the same information, (b) the facilitator did not have access to the picture or activity, and (c) the facilitator was given false information about the picture or activity. The results showed that the clients typed the correct answer only when the facilitator had access to the same information, never typed the correct answer when the facilitator had no information or false information, and typed the picture or activity presented to the facilitator when it was different from the one experienced by the client. These results provide unequivocal evidence for facilitator control of typing during facilitated communication. PMID:7601804

  12. The Teacher and Town Planner as Facilitator.

    ERIC Educational Resources Information Center

    Peel, Deborah

    2000-01-01

    Discussion of theories of facilitation in teaching focuses on citizen participation and the role of the facilitator in town planning. Highlights include hierarchies of learning; student-centered learning; facilitating community participation; information technology skills and interpersonal skills; and a rationale for participation. (LRW)

  13. Technologies and Techniques for Supporting Facilitated Video

    ERIC Educational Resources Information Center

    Linnell, Natalie

    2011-01-01

    Worldwide, demand for education of all kinds is increasing beyond the capacity to provide it. One approach that shows potential for addressing this demand is facilitated video. In facilitated video, an educator is recorded teaching, and that video is sent to a remote site where it is shown to students by a facilitator who creates interaction…

  14. Gesture recognition on smart cameras

    NASA Astrophysics Data System (ADS)

    Dziri, Aziz; Chevobbe, Stephane; Darouich, Mehdi

    2013-02-01

    Gesture recognition is a feature in human-machine interaction that allows more natural interaction without the use of complex devices. For this reason, several methods of gesture recognition have been developed in recent years. However, most real time methods are designed to operate on a Personal Computer with high computing resources and memory. In this paper, we analyze relevant methods found in the literature in order to investigate the ability of smart camera to execute gesture recognition algorithms. We elaborate two hand gesture recognition pipelines. The first method is based on invariant moments extraction and the second on finger tips detection. The hand detection method used for both pipeline is based on skin color segmentation. The results obtained show that the un-optimized versions of invariant moments method and finger tips detection method can reach 10 fps on embedded processor and use about 200 kB of memory.

  15. Face recognition based tensor structure

    NASA Astrophysics Data System (ADS)

    Yang, De-qiang; Ye, Zhi-xia; Zhao, Yang; Liu, Li-mei

    2012-01-01

    Face recognition has broad applications, and it is a difficult problem since face image can change with photographic conditions, such as different illumination conditions, pose changes and camera angles. How to obtain some invariable features for a face image is the key issue for a face recognition algorithm. In this paper, a novel tensor structure of face image is proposed to represent image features with eight directions for a pixel value. The invariable feature of the face image is then obtained from gradient decomposition to make up the tensor structure. Then the singular value decomposition (SVD) and principal component analysis (PCA) of this tensor structure are used for face recognition. The experimental results from this study show that many difficultly recognized samples can correctly be recognized, and the recognition rate is increased by 9%-11% in comparison with same type of algorithms.

  16. Processing orientation and emotion recognition.

    PubMed

    Martin, Douglas; Slessor, Gillian; Allen, Roy; Phillips, Louise H; Darling, Stephen

    2012-02-01

    There is evidence that some emotional expressions are characterized by diagnostic cues from individual face features. For example, an upturned mouth is indicative of happiness, whereas a furrowed brow is associated with anger. The current investigation explored whether motivating people to perceive stimuli in a local (i.e., feature-based) rather than global (i.e., holistic) processing orientation was advantageous for recognizing emotional facial expressions. Participants classified emotional faces while primed with local and global processing orientations, via a Navon letter task. Contrary to previous findings for identity recognition, the current findings are indicative of a modest advantage for face emotion recognition under conditions of local processing orientation. When primed with a local processing orientation, participants performed both significantly faster and more accurately on an emotion recognition task than when they were primed with a global processing orientation. The impacts of this finding for theories of emotion recognition and face processing are considered. PMID:21842989

  17. Health information use in home care: brainstorming barriers, facilitators, and recommendations.

    PubMed

    Stolee, Paul; Steeves, Brandie; Manderson, Brooke L; Toscan, Justine L; Glenny, Christine; Berg, Katherine

    2010-01-01

    There is growing recognition of the importance of sharing health information in home care; however, limited research exists to identify appropriate strategies, especially with home care providers. We engaged home care stakeholders from three locations in Ontario to determine facilitators, barriers, and recommendations for using health information in home care. The results suggest that health professionals recognize the potential of these systems to enhance communication through several emergent themes; however, there was a lack of agreement on the current facilitators, barriers, and recommendations for future interventions. More research is needed to achieve consensus before strategies for improvement can be initiated.

  18. The neuroecology of competitor recognition.

    PubMed

    Grether, Gregory F

    2011-11-01

    Territorial animals can be expected to distinguish among the types of competitors and noncompetitors that they encounter on a regular basis, including prospective mates and rivals of their own species, but they may not correctly classify individuals of other species. Closely related species often have similar phenotypes and this can cause confusion when formerly allopatric populations first come into contact. Errors in recognizing competitors can have important ecological and evolutionary effects. I review what is known about the mechanisms of competitor recognition in animals generally, focusing on cases in which the targets of recognition include other species. Case studies include damselflies, ants, skinks, salamanders, reef fishes, and birds. In general, recognition systems consist of a phenotypic cue (e.g., chemical, color, song), a neural template against which cues are compared, a motor response (e.g., aggression), and sensory integration circuits for context dependency of the response (if any). Little is known about how competitor recognition systems work at the neural level, but inferences about specificity of cues and about sensory integration can be drawn from the responses of territory residents to simulated intruders. Competitor recognition often involves multiple cues in the same, or different, sensory modalities. The same cues and templates are often, but not always, used for intraspecific and interspecific recognition. Experiments have shown that imprinting on local cues is common, which may enable templates to track evolved changes in cues automatically. The dependence of aggression and tolerance on context is important even in the simplest systems. Species in which mechanisms of competitor recognition are best known offer untapped opportunities to examine how competitor-recognition systems evolve (e.g., by comparing allopatric and sympatric populations). Cues that are gene products (peptides, proteins) may provide insights into rates of evolution

  19. On Tangut Historical Documents Recognition*

    NASA Astrophysics Data System (ADS)

    Liu, Changqing

    As the Tangut studies have made progress, a considerable number of Tangut historical documents' copies have been published. It is of great importance to carry out digitalization and domestication of these copies. The paper firstly makes an initial processing of images by global threshold, then dissect the photocopies by scanning. Finally adopts the recognition approach of principal component analysis. The experiment shows that a better recognition can be achieved by calculation without extra time.

  20. Memory asymmetry of forward and backward associations in recognition tasks.

    PubMed

    Yang, Jiongjiong; Zhao, Peng; Zhu, Zijian; Mecklinger, Axel; Fang, Zhiyong; Li, Han

    2013-01-01

    There is an intensive debate on whether memory for serial order is symmetric. The objective of this study was to explore whether associative asymmetry is modulated by memory task (recognition vs. cued recall). Participants were asked to memorize word triples (Experiments 1-2) or pairs (Experiments 3-6) during the study phase. They then recalled the word by a cue during a cued recall task (Experiments 1-4) and judged whether the presented 2 words were in the same or in a different order compared with the study phase during a recognition task (Experiments 1-6). To control for perceptual matching between the study and test phase, participants were presented with vertical test pairs when they made directional judgment in Experiment 5. In Experiment 6, participants also made associative recognition judgments for word pairs presented at the same or the reversed position. The results showed that forward associations were recalled at similar levels as backward associations and that the correlations between forward and backward associations were high in the cued recall tasks. On the other hand, the direction of forward associations was recognized more accurately (and more quickly) than backward associations, and their correlations were comparable to the control condition in the recognition tasks. This forward advantage was also obtained for the associative recognition task. Diminishing positional information did not change the pattern of associative asymmetry. These results suggest that associative asymmetry is modulated by cued recall and recognition manipulations and that direction as a constituent part of a memory trace can facilitate associative memory.

  1. Holistic processing predicts face recognition.

    PubMed

    Richler, Jennifer J; Cheung, Olivia S; Gauthier, Isabel

    2011-04-01

    The concept of holistic processing is a cornerstone of face-recognition research. In the study reported here, we demonstrated that holistic processing predicts face-recognition abilities on the Cambridge Face Memory Test and on a perceptual face-identification task. Our findings validate a large body of work that relies on the assumption that holistic processing is related to face recognition. These findings also reconcile the study of face recognition with the perceptual-expertise work it inspired; such work links holistic processing of objects with people's ability to individuate them. Our results differ from those of a recent study showing no link between holistic processing and face recognition. This discrepancy can be attributed to the use in prior research of a popular but flawed measure of holistic processing. Our findings salvage the central role of holistic processing in face recognition and cast doubt on a subset of the face-perception literature that relies on a problematic measure of holistic processing.

  2. Facilitated diffusion framework for transcription factor search with conformational changes

    NASA Astrophysics Data System (ADS)

    Cartailler, Jérôme; Reingruber, Jürgen

    2015-07-01

    Cellular responses often require the fast activation or repression of specific genes, which depends on transcription factors (TFs) that have to quickly find the promoters of these genes within a large genome. TFs search for their DNA promoter target by alternating between bulk diffusion and sliding along the DNA, a mechanism known as facilitated diffusion. We study a facilitated diffusion framework with switching between three search modes: a bulk mode and two sliding modes triggered by conformational changes between two protein conformations. In one conformation (search mode) the TF interacts unspecifically with the DNA backbone resulting in fast sliding. In the other conformation (recognition mode) it interacts specifically and strongly with DNA base pairs leading to slow displacement. From the bulk, a TF associates with the DNA at a random position that is correlated with the previous dissociation point, which implicitly is a function of the DNA structure. The target affinity depends on the conformation. We derive exact expressions for the mean first passage time (MFPT) to bind to the promoter and the conditional probability to bind before detaching when arriving at the promoter site. We systematically explore the parameter space and compare various search scenarios. We compare our results with experimental data for the dimeric Lac repressor search in E. coli bacteria. We find that a coiled DNA conformation is absolutely necessary for a fast MFPT. With frequent spontaneous conformational changes, a fast search time is achieved even when a TF becomes immobilized in the recognition state due to the specific bindings. We find a MFPT compatible with experimental data in presence of a specific TF-DNA interaction energy that has a Gaussian distribution with a large variance.

  3. Prevalence and Correlates of Drug/Alcohol-Facilitated and Incapacitated Sexual Assault in a Nationally Representative Sample of Adolescent Girls

    ERIC Educational Resources Information Center

    McCauley, Jenna L.; Conoscenti, Lauren M.; Ruggiero, Kenneth J.; Resnick, Heidi S.; Saunders, Benjamin E.; Kilpatrick, Dean G.

    2009-01-01

    Incapacitated/drug-alcohol facilitated sexual assault (IS/DAFS) is rapidly gaining recognition as a distinct form of assault with unique public health implications. This study reports the prevalence, case characteristics, and associated health risks of IS/DAFS using a large, nationally representative sample of 1,763 adolescent girls. Results…

  4. Document Form and Character Recognition using SVM

    NASA Astrophysics Data System (ADS)

    Park, Sang-Sung; Shin, Young-Geun; Jung, Won-Kyo; Ahn, Dong-Kyu; Jang, Dong-Sik

    2009-08-01

    Because of development of computer and information communication, EDI (Electronic Data Interchange) has been developing. There is OCR (Optical Character Recognition) of Pattern recognition technology for EDI. OCR contributed to changing many manual in the past into automation. But for the more perfect database of document, much manual is needed for excluding unnecessary recognition. To resolve this problem, we propose document form based character recognition method in this study. Proposed method is divided into document form recognition part and character recognition part. Especially, in character recognition, change character into binarization by using SVM algorithm and extract more correct feature value.

  5. Online handwritten script recognition.

    PubMed

    Namboodiri, Anoop M; Jain, Anil K

    2004-01-01

    Automatic identification of handwritten script facilitates many important applications such as automatic transcription of multilingual documents and search for documents on the Web containing a particular script. The increase in usage of handheld devices which accept handwritten input has created a growing demand for algorithms that can efficiently analyze and retrieve handwritten data. This paper proposes a method to classify words and lines in an online handwritten document into one of the six major scripts: Arabic, Cyrillic, Devnagari, Han, Hebrew, or Roman. The classification is based on 11 different spatial and temporal features extracted from the strokes of the words. The proposed system attains an overall classification accuracy of 87.1 percent at the word level with 5-fold cross validation on a data set containing 13,379 words. The classification accuracy improves to 95 percent as the number of words in the test sample is increased to five, and to 95.5 percent for complete text lines consisting of an average of seven words. PMID:15382692

  6. High-density myoelectric pattern recognition toward improved stroke rehabilitation.

    PubMed

    Zhang, Xu; Zhou, Ping

    2012-06-01

    Myoelectric pattern-recognition techniques have been developed to infer user's intention of performing different functional movements. Thus electromyogram (EMG) can be used as control signals of assisted devices for people with disabilities. Pattern-recognition-based myoelectric control systems have rarely been designed for stroke survivors. Aiming at developing such a system for improved stroke rehabilitation, this study assessed detection of the affected limb's movement intention using high-density surface EMG recording and pattern-recognition techniques. Surface EMG signals comprised of 89 channels were recorded from 12 hemiparetic stroke subjects while they tried to perform 20 different arm, hand, and finger/thumb movements involving the affected limb. A series of pattern-recognition algorithms were implemented to identify the intended tasks of each stroke subject. High classification accuracies (96.1% ± 4.3%) were achieved, indicating that substantial motor control information can be extracted from paretic muscles of stroke survivors. Such information may potentially facilitate improved stroke rehabilitation.

  7. Processing of disgusted faces is facilitated by odor primes: a functional MRI study.

    PubMed

    Seubert, Janina; Kellermann, Thilo; Loughead, James; Boers, Frank; Brensinger, Colleen; Schneider, Frank; Habel, Ute

    2010-11-01

    Facilitation of emotional face recognition is an established phenomenon for audiovisual crossmodal stimulation, but not for other sensory modalities. The present study used a crossmodal priming task to identify brain systems controlling olfactory-visual interactions during emotion processing. BOLD fMRI was acquired for 44 healthy subjects during an emotional face discrimination task preceded by an emotionally valenced odorant. Behavioral performance showed that recognition of disgusted faces was improved by the presentation of an olfactory stimulus irrespective of its emotional valence. No such facilitation was seen for other facial expressions. The neuroimaging data showed a selective default network responsivity to emotional faces which was modulated by odor condition. Among disgust faces, hypoactivations during trials preceded by odorants indicated the presence of priming effects. Consistent with studies investigating the brain systems associated with audiovisual emotional integration, activity modulations in clusters in fusiform gyrus, middle frontal and middle cingulate gyrus corresponded to the observed behavioral facilitation. Our study further shows modulation of signal in the anterior insula during trials combining negatively valenced odor and disgusted faces, suggesting a modality-specific mechanism for integration of the disgust response and olfaction. These results indicate the presence of a central network with modality-specific and -unspecific components modulating emotional face recognition. PMID:20627130

  8. An experimental assessment of facilitated communication.

    PubMed

    Wheeler, D L; Jacobson, J W; Paglieri, R A; Schwartz, A A

    1993-02-01

    This report presents a quantitative study of facilitated communication. Participants were 12 people living at an institutional autism program and 9 people who provided them with facilitated communication support. These subjects were the 12 most competent producers of facilitated communication in the program. They were shown pictures of familiar objects and asked to type the names of the objects under three conditions: (a) assisted typing with facilitators unaware of the content of the stimulus picture, (b) unassisted typing, and (c) a condition in which the participants and facilitators were each shown pictures at the same time. In this last condition the paired pictures were either the same or different, and the participant's typing was facilitated to label or describe the picture. These participants were unable to succeed in the tasks without facilitator assistance. On trials when the facilitators and participants had different pictures, the only "correct" labels were for pictures shown to the facilitators and not shown to the participants. This finding demonstrates that the facilitators were unknowingly determining what was typed.

  9. Design and biological activity of {beta}-sheet breaker peptide conjugates

    SciTech Connect

    Rocha, Sandra Cardoso, Isabel; Boerner, Hans; Pereira, Maria Carmo; Saraiva, Maria Joao; Coelho, Manuel

    2009-03-06

    The sequence LPFFD (iA{beta}{sub 5}) prevents amyloid-{beta} peptide (A{beta}) fibrillogenesis and neurotoxicity, hallmarks of Alzheimer's disease (AD), as previously demonstrated. In this study iA{beta}{sub 5} was covalently linked to poly(ethylene glycol) (PEG) and the activity of conjugates was assessed and compared to the activity of the peptide alone by in vitro studies. The conjugates were characterized by MALDI-TOF. Competition binding assays established that conjugates retained the ability to bind A{beta} with similar strength as iA{beta}{sub 5}. Transmission electron microscopy analysis showed that iA{beta}{sub 5} conjugates inhibited amyloid fibril formation, which is in agreement with binding properties observed for the conjugates towards A{beta}. The conjugates were also able to prevent amyloid-induced cell death, as evaluated by activation of caspase 3. These results demonstrated that the biological activity of iA{beta}{sub 5} is not affected by the pegylation process.

  10. Microphase Separation Controlled beta-Sheet Crystallization Kinetics in Fibrous Proteins

    SciTech Connect

    Hu, X.; Lu, Q; Kaplan, D; Cebe, P

    2009-01-01

    Silk is a naturally occurring fibrous protein with a multiblock chain architecture. As such, it has many similarities with synthetic block copolymers, including the possibility for e-sheet crystallization restricted within the crystallizable blocks. The mechanism of isothermal crystallization kinetics of e-sheet crystals in silk multiblock fibrous proteins is reported in this study. Kinetics theories, such as Avrami analysis which was established for studies of synthetic polymer crystal growth, are for the first time extended to investigate protein self-assembly in e-sheet rich Bombyx mori silk fibroin samples, using time-resolved Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and synchrotron real-time wide-angle X-ray scattering (WAXS). The Avrami exponent, n, was close to 2 for all methods and crystallization temperatures, indicating formation of e-sheet crystals in silk proteins is different from the 3-D spherulitic crystal growth found in synthetic polymers. Observations by scanning electron microscopy support the view that the protein structures vary during the different stages of crystal growth, and show a microphase separation pattern after chymotrypsin enzyme biodegradation. We present a model to explain the crystallization of the multiblock silk fibroin protein, by analogy to block copolymers: crystallization of e-sheets occurs under conditions of geometrical restriction caused by phase separation of the crystallizable and uncrystallizable blocks. This crystallization model could be widely applicable in other proteins with multiblock (i.e., crystallizable and noncrystallizable) domains.

  11. Liquid Crystal Based Sensor to Detect Beta-Sheet Formation of Peptides

    NASA Astrophysics Data System (ADS)

    Sadati, Monirosadat; Izmitli Apik, Aslin; Abbott, Nicholas L.; de Pablo, Juan J.

    2015-03-01

    Protein aggregation into amyloid fibrils is involved in the progression of Alzheimer's, typeII diabetes and Huntington's diseases. Although larger aggregates remain important for clinical determination, small oligomers are of great interest due to their potentially toxic nature. It is therefore crucial to develop methods that probe the aggregation process at early stages and in the vicinity of biological membranes. Here, we present a simple method that relies on liquid crystalline materials and a Langmuir monolayer at the aqueous-liquid crystal (LC) interface. The approach is based on the LC's specific response to β-sheet structures, which abound in amyloid fibrils. When the system is observed under polarized light, the fibrils formed by amyloidogenic peptides give rise to the formation of elongated and branched structures in the LCs. Moreover, the PolScope measurements prove that the LCs are predominantly aligned along the fibrils when exposed to a β-sheet forming peptide. In contrast, non-amyloidogenic peptides form ellipsoidal domains of irregularly tilted LCs. This method is capable of reporting aggregation at lipid-aqueous interfaces at nanomolar concentrations of the peptide, and much earlier than commonly used fluorescence-based techniques. We thank Prof. Oleg D. Levrentovich and Young-Ki Kim from the Liquid Crystal Institute of Kent State University for the use of their PolScope instrument. This work was partially supported by the Swiss National Science Foundation (P300P2_151342).

  12. Efficient traversal of beta-sheet protein folding pathways using ensemble models.

    PubMed

    Shenker, Solomon; O'Donnell, Charles W; Devadas, Srinivas; Berger, Bonnie; Waldispühl, Jérôme

    2011-11-01

    Molecular dynamics (MD) simulations can now predict ms-timescale folding processes of small proteins; however, this presently requires hundreds of thousands of CPU hours and is primarily applicable to short peptides with few long-range interactions. Larger and slower-folding proteins, such as many with extended β-sheet structure, would require orders of magnitude more time and computing resources. Furthermore, when the objective is to determine only which folding events are necessary and limiting, atomistic detail MD simulations can prove unnecessary. Here, we introduce the program tFolder as an efficient method for modelling the folding process of large β-sheet proteins using sequence data alone. To do so, we extend existing ensemble β-sheet prediction techniques, which permitted only a fixed anti-parallel β-barrel shape, with a method that predicts arbitrary β-strand/β-strand orientations and strand-order permutations. By accounting for all partial and final structural states, we can then model the transition from random coil to native state as a Markov process, using a master equation to simulate population dynamics of folding over time. Thus, all putative folding pathways can be energetically scored, including which transitions present the greatest barriers. Since correct folding pathway prediction is likely determined by the accuracy of contact prediction, we demonstrate the accuracy of tFolder to be comparable with state-of-the-art methods designed specifically for the contact prediction problem alone. We validate our method for dynamics prediction by applying it to the folding pathway of the well-studied Protein G. With relatively very little computation time, tFolder is able to reveal critical features of the folding pathways which were only previously observed through time-consuming MD simulations and experimental studies. Such a result greatly expands the number of proteins whose folding pathways can be studied, while the algorithmic integration of ensemble prediction with Markovian dynamics can be applied to many other problems. PMID:21958108

  13. Reversible Hydrogel–Solution System of Silk with High Beta-Sheet Content

    PubMed Central

    2015-01-01

    Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The β-sheet-rich natural nanofiber units of about 10–50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of β-sheet-rich silk nanofibers about 10–20 nm in diameter is reported here, where these nanofibers formed into “flowing hydrogels” at 0.5–2% solutions and could be transformed back into the solution state at lower concentrations, even with a high β-sheet content. This is in contrast with other silk processed materials, where significant β-sheet content negates reversibility between solution and solid states. These fibers are formed by regulating the self-assembly process of silk in aqueous solution, which changes the distribution of negative charges while still supporting β-sheet formation in the structures. Mechanistically, there appears to be a shift toward negative charges along the outside of the silk nanofibers in our present study, resulting in a higher zeta potential (above −50 mV) than previous silk materials which tend to be below −30 mV. The higher negative charge on silk nanofibers resulted in electrostatic repulsion strong enough to negate further assembly of the nanofibers. Changing silk concentration changed the balance between hydrophobic interactions and electrostatic repulsion of β-sheet-rich silk nanofibers, resulting in reversible hydrogel–solution transitions. Furthermore, the silk nanofibers could be disassembled into shorter fibers and even nanoparticles upon ultrasonic treatment following the transition from hydrogel to solution due to the increased dispersion of hydrophobic smaller particles, without the loss of β-sheet content, and with retention of the ability to transition between hydrogel and solution states through reversion to longer nanofibers during self-assembly. These reversible solution-hydrogel transitions were tunable with ultrasonic intensity, time, or temperature. PMID:25056606

  14. Reversible hydrogel-solution system of silk with high beta-sheet content.

    PubMed

    Bai, Shumeng; Zhang, Xiuli; Lu, Qiang; Sheng, Weiqin; Liu, Lijie; Dong, Boju; Kaplan, David L; Zhu, Hesun

    2014-08-11

    Silkworm silk has been widely used as a textile fiber, as biomaterials and in optically functional materials due to its extraordinary properties. The β-sheet-rich natural nanofiber units of about 10-50 nm in diameter are often considered the origin of these properties, yet it remains unclear how silk self-assembles into these hierarchical structures. A new system composed of β-sheet-rich silk nanofibers about 10-20 nm in diameter is reported here, where these nanofibers formed into "flowing hydrogels" at 0.5-2% solutions and could be transformed back into the solution state at lower concentrations, even with a high β-sheet content. This is in contrast with other silk processed materials, where significant β-sheet content negates reversibility between solution and solid states. These fibers are formed by regulating the self-assembly process of silk in aqueous solution, which changes the distribution of negative charges while still supporting β-sheet formation in the structures. Mechanistically, there appears to be a shift toward negative charges along the outside of the silk nanofibers in our present study, resulting in a higher zeta potential (above -50 mV) than previous silk materials which tend to be below -30 mV. The higher negative charge on silk nanofibers resulted in electrostatic repulsion strong enough to negate further assembly of the nanofibers. Changing silk concentration changed the balance between hydrophobic interactions and electrostatic repulsion of β-sheet-rich silk nanofibers, resulting in reversible hydrogel-solution transitions. Furthermore, the silk nanofibers could be disassembled into shorter fibers and even nanoparticles upon ultrasonic treatment following the transition from hydrogel to solution due to the increased dispersion of hydrophobic smaller particles, without the loss of β-sheet content, and with retention of the ability to transition between hydrogel and solution states through reversion to longer nanofibers during self-assembly. These reversible solution-hydrogel transitions were tunable with ultrasonic intensity, time, or temperature.

  15. Beta-Sheet-Forming, Self-Assembled Peptide Nanomaterials towards Optical, Energy, and Healthcare Applications.

    PubMed

    Kim, Sungjin; Kim, Jae Hong; Lee, Joon Seok; Park, Chan Beum

    2015-08-12

    Peptide self-assembly is an attractive route for the synthesis of intricate organic nanostructures that possess remarkable structural variety and biocompatibility. Recent studies on peptide-based, self-assembled materials have expanded beyond the construction of high-order architectures; they are now reporting new functional materials that have application in the emerging fields such as artificial photosynthesis and rechargeable batteries. Nevertheless, there have been few reviews particularly concentrating on such versatile, emerging applications. Herein, recent advances in the synthesis of self-assembled peptide nanomaterials (e.g., cross β-sheet-based amyloid nanostructures, peptide amphiphiles) are selectively reviewed and their new applications in diverse, interdisciplinary fields are described, ranging from optics and energy storage/conversion to healthcare. The applications of peptide-based self-assembled materials in unconventional fields are also highlighted, such as photoluminescent peptide nanostructures, artificial photosynthetic peptide nanomaterials, and lithium-ion battery components. The relation of such functional materials to the rapidly progressing biomedical applications of peptide self-assembly, which include biosensors/chips and regenerative medicine, are discussed. The combination of strategies shown in these applications would further promote the discovery of novel, functional, small materials. PMID:25929870

  16. The Effects of Semantic Transparency and Base Frequency on the Recognition of English Complex Words

    ERIC Educational Resources Information Center

    Xu, Joe; Taft, Marcus

    2015-01-01

    A visual lexical decision task was used to examine the interaction between base frequency (i.e., the cumulative frequencies of morphologically related forms) and semantic transparency for a list of derived words. Linear mixed effects models revealed that high base frequency facilitates the recognition of the complex word (i.e., a "base…

  17. Priming Contour-Deleted Images: Evidence for Immediate Representations in Visual Object Recognition.

    ERIC Educational Resources Information Center

    Biederman, Irving; Cooper, Eric E.

    1991-01-01

    Speed and accuracy of identification of pictures of objects are facilitated by prior viewing. Contributions of image features, convex or concave components, and object models in a repetition priming task were explored in 2 studies involving 96 college students. Results provide evidence of intermediate representations in visual object recognition.…

  18. How Do Professional Mutual Recognition Agreements Affect Higher Education? Examining Regional Policy in North America

    ERIC Educational Resources Information Center

    Sa, Creso; Gaviria, Patricia

    2011-01-01

    Professional mutual recognition agreements (MRAs) are one of the policy instruments employed in global and regional trade agreements to facilitate the mobility of skilled labour. While such agreements have been noted in the literature examining cross-border academic mobility, little is known about how they impact higher education. This paper…

  19. Professional Mobility and the Mutual Recognition of Qualifications in the European Union: Two Institutional Approaches.

    ERIC Educational Resources Information Center

    Blitz, Brad K.

    1999-01-01

    Examines the role of transnational institutions (particularly the European Commission and committees of the European Parliament) in facilitating the mutual recognition of professional qualifications among members of the European Economic Community (EEC). Discusses relevant EEC directives, varying compliance among nations, and six cases of citizen…

  20. Probing secondary interactions in biomolecular recognition by dynamic combinatorial chemistry.

    PubMed

    Ulrich, Sébastien; Dumy, Pascal

    2014-06-01

    Artificial multivalent recognition systems offer promising perspectives for developing synthetic compounds capable of interacting effectively and selectively with biomolecules in aqueous medium. The identification of multi-point binding ligands requires screening of a large number of complex structures, with different spacers, different ligands, and varying valency. This represents a challenge for rational design approaches. On the other hand, the use of dynamic covalent chemistry enables a target-driven one-pot screening approach for probing secondary interactions, thereby facilitating the identification of multivalent recognition systems that optimally combine multiple fragments. Herein we review the recent developments in the implementation of dynamic combinatorial chemistry for probing secondary interactions and thereby identify multi-point binding ligands of biomolecules.

  1. Bidirectional Modulation of Recognition Memory

    PubMed Central

    Ho, Jonathan W.; Poeta, Devon L.; Jacobson, Tara K.; Zolnik, Timothy A.; Neske, Garrett T.; Connors, Barry W.

    2015-01-01

    Perirhinal cortex (PER) has a well established role in the familiarity-based recognition of individual items and objects. For example, animals and humans with perirhinal damage are unable to distinguish familiar from novel objects in recognition memory tasks. In the normal brain, perirhinal neurons respond to novelty and familiarity by increasing or decreasing firing rates. Recent work also implicates oscillatory activity in the low-beta and low-gamma frequency bands in sensory detection, perception, and recognition. Using optogenetic methods in a spontaneous object exploration (SOR) task, we altered recognition memory performance in rats. In the SOR task, normal rats preferentially explore novel images over familiar ones. We modulated exploratory behavior in this task by optically stimulating channelrhodopsin-expressing perirhinal neurons at various frequencies while rats looked at novel or familiar 2D images. Stimulation at 30–40 Hz during looking caused rats to treat a familiar image as if it were novel by increasing time looking at the image. Stimulation at 30–40 Hz was not effective in increasing exploration of novel images. Stimulation at 10–15 Hz caused animals to treat a novel image as familiar by decreasing time looking at the image, but did not affect looking times for images that were already familiar. We conclude that optical stimulation of PER at different frequencies can alter visual recognition memory bidirectionally. SIGNIFICANCE STATEMENT Recognition of novelty and familiarity are important for learning, memory, and decision making. Perirhinal cortex (PER) has a well established role in the familiarity-based recognition of individual items and objects, but how novelty and familiarity are encoded and transmitted in the brain is not known. Perirhinal neurons respond to novelty and familiarity by changing firing rates, but recent work suggests that brain oscillations may also be important for recognition. In this study, we showed that

  2. Cognitive object recognition system (CORS)

    NASA Astrophysics Data System (ADS)

    Raju, Chaitanya; Varadarajan, Karthik Mahesh; Krishnamurthi, Niyant; Xu, Shuli; Biederman, Irving; Kelley, Troy

    2010-04-01

    We have developed a framework, Cognitive Object Recognition System (CORS), inspired by current neurocomputational models and psychophysical research in which multiple recognition algorithms (shape based geometric primitives, 'geons,' and non-geometric feature-based algorithms) are integrated to provide a comprehensive solution to object recognition and landmarking. Objects are defined as a combination of geons, corresponding to their simple parts, and the relations among the parts. However, those objects that are not easily decomposable into geons, such as bushes and trees, are recognized by CORS using "feature-based" algorithms. The unique interaction between these algorithms is a novel approach that combines the effectiveness of both algorithms and takes us closer to a generalized approach to object recognition. CORS allows recognition of objects through a larger range of poses using geometric primitives and performs well under heavy occlusion - about 35% of object surface is sufficient. Furthermore, geon composition of an object allows image understanding and reasoning even with novel objects. With reliable landmarking capability, the system improves vision-based robot navigation in GPS-denied environments. Feasibility of the CORS system was demonstrated with real stereo images captured from a Pioneer robot. The system can currently identify doors, door handles, staircases, trashcans and other relevant landmarks in the indoor environment.

  3. An audiovisual emotion recognition system

    NASA Astrophysics Data System (ADS)

    Han, Yi; Wang, Guoyin; Yang, Yong; He, Kun

    2007-12-01

    Human emotions could be expressed by many bio-symbols. Speech and facial expression are two of them. They are both regarded as emotional information which is playing an important role in human-computer interaction. Based on our previous studies on emotion recognition, an audiovisual emotion recognition system is developed and represented in this paper. The system is designed for real-time practice, and is guaranteed by some integrated modules. These modules include speech enhancement for eliminating noises, rapid face detection for locating face from background image, example based shape learning for facial feature alignment, and optical flow based tracking algorithm for facial feature tracking. It is known that irrelevant features and high dimensionality of the data can hurt the performance of classifier. Rough set-based feature selection is a good method for dimension reduction. So 13 speech features out of 37 ones and 10 facial features out of 33 ones are selected to represent emotional information, and 52 audiovisual features are selected due to the synchronization when speech and video fused together. The experiment results have demonstrated that this system performs well in real-time practice and has high recognition rate. Our results also show that the work in multimodules fused recognition will become the trend of emotion recognition in the future.

  4. Pollinator recognition by a keystone tropical plant

    PubMed Central

    Betts, Matthew G.; Hadley, Adam S.; Kress, W. John

    2015-01-01

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (x¯ pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (x¯ pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant–pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change. PMID:25733902

  5. Pollinator recognition by a keystone tropical plant.

    PubMed

    Betts, Matthew G; Hadley, Adam S; Kress, W John

    2015-03-17

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (mean pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (mean pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant-pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change.

  6. Pollinator recognition by a keystone tropical plant.

    PubMed

    Betts, Matthew G; Hadley, Adam S; Kress, W John

    2015-03-17

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (mean pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (mean pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant-pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change. PMID:25733902

  7. 50 CFR 17.107 - Facilitating enforcement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS (CONTINUED) Manatee Protection Areas § 17.107 Facilitating enforcement. Water vehicles operating in manatee sanctuary or...

  8. 50 CFR 17.107 - Facilitating enforcement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS (CONTINUED) Manatee Protection Areas § 17.107 Facilitating enforcement. Water vehicles operating in manatee sanctuary or...

  9. 50 CFR 17.107 - Facilitating enforcement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS (CONTINUED) Manatee Protection Areas § 17.107 Facilitating enforcement. Water vehicles operating in manatee sanctuary or...

  10. 50 CFR 17.107 - Facilitating enforcement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS (CONTINUED) Manatee Protection Areas § 17.107 Facilitating enforcement. Water vehicles operating in manatee sanctuary or...

  11. 50 CFR 17.107 - Facilitating enforcement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... WILDLIFE AND PLANTS (CONTINUED) ENDANGERED AND THREATENED WILDLIFE AND PLANTS (CONTINUED) Manatee Protection Areas § 17.107 Facilitating enforcement. Water vehicles operating in manatee sanctuary or...

  12. Simple scale interpolator facilitates reading of graphs

    NASA Technical Reports Server (NTRS)

    Fetterman, D. E., Jr.

    1965-01-01

    Simple transparent overlay with interpolation scale facilitates accurate, rapid reading of graph coordinate points. This device can be used for enlarging drawings and locating points on perspective drawings.

  13. Asymmetric Reinstatement Effects in Recognition.

    PubMed

    Shahabuddin, Shaan S; Smith, Steven M

    2016-01-01

    Our experiment examined two questions: (1) Does reinstating a studied context affect recognition of an associated word, and (2) Does reinstating a studied word affect recognition of an associated context? After encoding 75 words, each of which was shown superimposed over a different 5-sec video of an environment (e.g., a playground, a traffic scene, or a grocery store), participants were asked to recognize 50 of the words and 50 of the video scenes. On the test, half of the studied words were shown superimposed over the same video contexts that had been present at encoding, and half were shown over new scenes. Similarly, videos were presented with either old or new words. Context reinstatement increased hits and reduced false alarms for words, but word reinstatement did not affect recognition of video contexts. The results suggest that the associations that bind word events with their contexts may not be bidirectional. PMID:27649359

  14. Palmprint Recognition across Different Devices

    PubMed Central

    Jia, Wei; Hu, Rong-Xiang; Gui, Jie; Zhao, Yang; Ren, Xiao-Ming

    2012-01-01

    In this paper, the problem of Palmprint Recognition Across Different Devices (PRADD) is investigated, which has not been well studied so far. Since there is no publicly available PRADD image database, we created a non-contact PRADD image database containing 12,000 grayscale captured from 100 subjects using three devices, i.e., one digital camera and two smart-phones. Due to the non-contact image acquisition used, rotation and scale changes between different images captured from a same palm are inevitable. We propose a robust method to calculate the palm width, which can be effectively used for scale normalization of palmprints. On this PRADD image database, we evaluate the recognition performance of three different methods, i.e., subspace learning method, correlation method, and orientation coding based method, respectively. Experiments results show that orientation coding based methods achieved promising recognition performance for PRADD. PMID:22969380

  15. DNA recognition by synthetic constructs.

    PubMed

    Pazos, Elena; Mosquera, Jesús; Vázquez, M Eugenio; Mascareñas, José L

    2011-09-01

    The interaction of transcription factors with specific DNA sites is key for the regulation of gene expression. Despite the availability of a large body of structural data on protein-DNA complexes, we are still far from fully understanding the molecular and biophysical bases underlying such interactions. Therefore, the development of non-natural agents that can reproduce the DNA-recognition properties of natural transcription factors remains a major and challenging goal in chemical biology. In this review we summarize the basics of double-stranded DNA recognition by transcription factors, and describe recent developments in the design and preparation of synthetic DNA binders. We mainly focus on synthetic peptides that have been designed by following the DNA interaction of natural proteins, and we discuss how the tools of organic synthesis can be used to make artificial constructs equipped with functionalities that introduce additional properties to the recognition process, such as sensing and controllability.

  16. Emotion-independent face recognition

    NASA Astrophysics Data System (ADS)

    De Silva, Liyanage C.; Esther, Kho G. P.

    2000-12-01

    Current face recognition techniques tend to work well when recognizing faces under small variations in lighting, facial expression and pose, but deteriorate under more extreme conditions. In this paper, a face recognition system to recognize faces of known individuals, despite variations in facial expression due to different emotions, is developed. The eigenface approach is used for feature extraction. Classification methods include Euclidean distance, back propagation neural network and generalized regression neural network. These methods yield 100% recognition accuracy when the training database is representative, containing one image representing the peak expression for each emotion of each person apart from the neutral expression. The feature vectors used for comparison in the Euclidean distance method and for training the neural network must be all the feature vectors of the training set. These results are obtained for a face database consisting of only four persons.

  17. Mandarin recognition over the telephone

    NASA Astrophysics Data System (ADS)

    Kao, Yuhung

    1996-06-01

    Mandarin Chinese is the official language in China and Taiwan, it is the native language of a quarter of the world population. As the services enabled by speech recognition technology (e.g. telephone voice dialing, information query) become more popular in English, we would like to extend this capability to other languages. Mandarin is one of the major languages under research in our laboratory. This paper describes how we extend our work in English speech recognition into Mandarin. We will described the corpus: Voice Across Taiwan, the training of a complete set of Mandarin syllable models, preliminary performance results and error analysis. A fast prototyping system was built, where a user can write any context free grammar with no restriction of vocabulary, then the grammar can be compiled into recognition models. It enables user to quickly test the performance of a new vocabulary.

  18. Dynamic detection of window starting positions and its implementation within an activity recognition framework.

    PubMed

    Ni, Qin; Patterson, Timothy; Cleland, Ian; Nugent, Chris

    2016-08-01

    Activity recognition is an intrinsic component of many pervasive computing and ambient intelligent solutions. This has been facilitated by an explosion of technological developments in the area of wireless sensor network, wearable and mobile computing. Yet, delivering robust activity recognition, which could be deployed at scale in a real world environment, still remains an active research challenge. Much of the existing literature to date has focused on applying machine learning techniques to pre-segmented data collected in controlled laboratory environments. Whilst this approach can provide valuable ground truth information from which to build recognition models, these techniques often do not function well when implemented in near real time applications. This paper presents the application of a multivariate online change detection algorithm to dynamically detect the starting position of windows for the purposes of activity recognition. PMID:27392647

  19. Using learning theory, interprofessional facilitation competencies, and behavioral indicators to evaluate facilitator training.

    PubMed

    LeGros, Theresa A; Amerongen, Helen M; Cooley, Janet H; Schloss, Ernest P

    2015-01-01

    Despite the increasing need for faculty and preceptors skilled in interprofessional facilitation (IPF), the relative novelty of the field poses a challenge to the development and evaluation of IPF programs. We use learning theory and IPF competencies with associated behavioral indicators to develop and evaluate six key messages in IPF training and experience. Our mixed methods approach included two phases: quantitative data collection with embedded qualitative data, followed by qualitative data collection in explanatory sequential fashion. This enabled triangulated analyses of both data types and of facilitation behaviors from facilitator and student perspectives. Results indicate the competency-based training was effective. Facilitators felt comfortable performing behaviors associated with IPF competencies; student observations of those behaviors supported facilitator self-reported performance. Overall, students perceived more facilitation opportunities than facilitators. Findings corroborate the importance of recruiting seasoned facilitators and establishing IPF guidelines that acknowledge variable team dynamics and help facilitators recognize teachable moments. PMID:26230378

  20. Using learning theory, interprofessional facilitation competencies, and behavioral indicators to evaluate facilitator training.

    PubMed

    LeGros, Theresa A; Amerongen, Helen M; Cooley, Janet H; Schloss, Ernest P

    2015-01-01

    Despite the increasing need for faculty and preceptors skilled in interprofessional facilitation (IPF), the relative novelty of the field poses a challenge to the development and evaluation of IPF programs. We use learning theory and IPF competencies with associated behavioral indicators to develop and evaluate six key messages in IPF training and experience. Our mixed methods approach included two phases: quantitative data collection with embedded qualitative data, followed by qualitative data collection in explanatory sequential fashion. This enabled triangulated analyses of both data types and of facilitation behaviors from facilitator and student perspectives. Results indicate the competency-based training was effective. Facilitators felt comfortable performing behaviors associated with IPF competencies; student observations of those behaviors supported facilitator self-reported performance. Overall, students perceived more facilitation opportunities than facilitators. Findings corroborate the importance of recruiting seasoned facilitators and establishing IPF guidelines that acknowledge variable team dynamics and help facilitators recognize teachable moments.

  1. Familiar Person Recognition: Is Autonoetic Consciousness More Likely to Accompany Face Recognition Than Voice Recognition?

    NASA Astrophysics Data System (ADS)

    Barsics, Catherine; Brédart, Serge

    2010-11-01

    Autonoetic consciousness is a fundamental property of human memory, enabling us to experience mental time travel, to recollect past events with a feeling of self-involvement, and to project ourselves in the future. Autonoetic consciousness is a characteristic of episodic memory. By contrast, awareness of the past associated with a mere feeling of familiarity or knowing relies on noetic consciousness, depending on semantic memory integrity. Present research was aimed at evaluating whether conscious recollection of episodic memories is more likely to occur following the recognition of a familiar face than following the recognition of a familiar voice. Recall of semantic information (biographical information) was also assessed. Previous studies that investigated the recall of biographical information following person recognition used faces and voices of famous people as stimuli. In this study, the participants were presented with personally familiar people's voices and faces, thus avoiding the presence of identity cues in the spoken extracts and allowing a stricter control of frequency exposure with both types of stimuli (voices and faces). In the present study, the rate of retrieved episodic memories, associated with autonoetic awareness, was significantly higher from familiar faces than familiar voices even though the level of overall recognition was similar for both these stimuli domains. The same pattern was observed regarding semantic information retrieval. These results and their implications for current Interactive Activation and Competition person recognition models are discussed.

  2. Stochastic Process Underlying Emergent Recognition of Visual Objects Hidden in Degraded Images

    PubMed Central

    Murata, Tsutomu; Hamada, Takashi; Shimokawa, Tetsuya; Tanifuji, Manabu; Yanagida, Toshio

    2014-01-01

    When a degraded two-tone image such as a “Mooney” image is seen for the first time, it is unrecognizable in the initial seconds. The recognition of such an image is facilitated by giving prior information on the object, which is known as top-down facilitation and has been intensively studied. Even in the absence of any prior information, however, we experience sudden perception of the emergence of a salient object after continued observation of the image, whose processes remain poorly understood. This emergent recognition is characterized by a comparatively long reaction time ranging from seconds to tens of seconds. In this study, to explore this time-consuming process of emergent recognition, we investigated the properties of the reaction times for recognition of degraded images of various objects. The results show that the time-consuming component of the reaction times follows a specific exponential function related to levels of image degradation and subject's capability. Because generally an exponential time is required for multiple stochastic events to co-occur, we constructed a descriptive mathematical model inspired by the neurophysiological idea of combination coding of visual objects. Our model assumed that the coincidence of stochastic events complement the information loss of a degraded image leading to the recognition of its hidden object, which could successfully explain the experimental results. Furthermore, to see whether the present results are specific to the task of emergent recognition, we also conducted a comparison experiment with the task of perceptual decision making of degraded images, which is well known to be modeled by the stochastic diffusion process. The results indicate that the exponential dependence on the level of image degradation is specific to emergent recognition. The present study suggests that emergent recognition is caused by the underlying stochastic process which is based on the coincidence of multiple stochastic events

  3. "Stepping Up": A Focus on Facilitator Development

    ERIC Educational Resources Information Center

    Kostouros, Patricia; Warthe, D. Gaye; Carter-Snell, Catherine; Burnett, Che

    2016-01-01

    This article examines the impact on peer facilitators in "Stepping Up," a dating violence prevention program at a Canadian university. A focus group held eight months following the delivery of the program determined the personal impact of involvement in the program. Results indicate that peer facilitators experienced personal growth as…

  4. Peervention: Training Peer Facilitators for Prevention Education.

    ERIC Educational Resources Information Center

    Myrick, Robert D.; Folk, Betsy E.

    This book introduces students to the helping relationship and appropriate methods of responding to others through a variety of experiential training activities. The first chapter discusses the need for peer facilitators. The peer facilitator movement is traced to the 1970s, and the power of peer relationships is described. Four basic helping roles…

  5. Parent Involvement Facilitators: Unlocking Social Capital Wealth

    ERIC Educational Resources Information Center

    Ferrara, Margaret M.

    2015-01-01

    This case study provides an overview of a family outreach intervention that supports student retention in school through a school-home communication link. This intervention structure, which employs staff appropriately called parent involvement facilitators (PIFs), is one that school districts have employed to facilitate family engagement in…

  6. Facilitated Communication: The Clinical and Social Phenomenon.

    ERIC Educational Resources Information Center

    Shane, Howard C., Ed.

    This text explains the phenomenon of facilitated communication (FC) from an empirical, data-based, and/or clinical perspective. It is not a how-to-facilitate text, but one that explores the clinical and sociological reality of FC. A common theme running through each of the papers in the book is the question of FC's legitimacy. The papers reveal…

  7. A Model of Small Group Facilitator Competencies

    ERIC Educational Resources Information Center

    Kolb, Judith A.; Jin, Sungmi; Song, Ji Hoon

    2008-01-01

    This study used small group theory, quantitative and qualitative data collected from experienced practicing facilitators at three points of time, and a building block process of collection, analysis, further collection, and consolidation to develop a model of small group facilitator competencies. The proposed model has five components:…

  8. 49 CFR 38.2 - Equivalent facilitation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Equivalent facilitation. 38.2 Section 38.2 Transportation Office of the Secretary of Transportation AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES General § 38.2 Equivalent facilitation. Departures from...

  9. 75 FR 64641 - Facilitating Shareholder Director Nominations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... COMMISSION 17 CFR Parts 200, 232, 240, and 249 RIN 3235-AK27 Facilitating Shareholder Director Nominations... rules that the Commission adopted to facilitate the effective exercise of shareholders' traditional state law rights to nominate and elect directors to company boards of directors. We are publishing...

  10. Escaping Homelessness: Anticipated and Perceived Facilitators

    ERIC Educational Resources Information Center

    Patterson, Allisha; Tweed, Roger

    2009-01-01

    One study with two distinct sections was conducted to identify factors facilitating escape from homelessness. In Section 1, 58 homeless individuals rated possible facilitators of escape (factors they believed would help them become more independent and self-sufficient). In Section 2, 80 participants who had already exited homelessness rated the…

  11. A Multitask Controlled Evaluation of Facilitated Communication.

    ERIC Educational Resources Information Center

    Vazquez, Carol A.

    1994-01-01

    This study tested the validity of facilitated communication with 2 students (ages 10 and 12) with autism, using a picture identification task, video task, and object identification. Subjects were able to report information unknown to the facilitator in one out of four controlled sessions. Strong evidence for direct cuing between subject and…

  12. Facilitator's Manual: Summer Transitions. Fifth Edition.

    ERIC Educational Resources Information Center

    Kuenzli, Linda A., Ed.

    A facilitator's manual for the Summer Transition Enrichment Program at Bowling Green State University is presented. The overall objectives of the program are: (1) to facilitate the transition of entering freshmen into the academic and cultural life of the university; and (2) to assist students in their personal growth and adjustment to the…

  13. The Role of Touch in Facilitated Communication.

    ERIC Educational Resources Information Center

    Kezuka, Emiko

    1997-01-01

    A study investigated the role of touch in the use of facilitated communication with Japanese individuals with autism. Five experiments were conducted involving a "telepathy game" using a rod with an attached strain gauge. Results found the facilitator's contact controlled the motor responses of the subjects. (Author/CR)

  14. Toward Facilitative Mentoring and Catalytic Interventions

    ERIC Educational Resources Information Center

    Smith, Melissa K.; Lewis, Marilyn

    2015-01-01

    In TESOL teacher mentoring, giving advice can be conceptualized as a continuum, ranging from directive to facilitative feedback. The goal, over time, is to lead toward the facilitative end of the continuum and specifically to catalytic interventions that encourage self-reflection and autonomous learning. This study begins by examining research on…

  15. Reconceptualizing the Pedagogical Value of Student Facilitation

    ERIC Educational Resources Information Center

    Oztok, Murat

    2016-01-01

    Sustained discourse is critical to the learning potential of online courses. And, while research has surfaced many factors that mediate interaction, it further suggests that sustained interaction remains elusive. In this paper, I propose that student facilitation may have an impact on the quality of facilitators' interactions following a week of…

  16. A Dialogic Approach to Online Facilitation

    ERIC Educational Resources Information Center

    Swann, Jennie

    2010-01-01

    Social construction of understanding has long been a significant underlying principle of learning and teaching, and while there are many models for the design of online activities to promote this, there are considerably fewer models for the facilitation of such dialogue. This paper examines some of these facilitation models from the point of view…

  17. Social Facilitation: A Test of Two Theories.

    ERIC Educational Resources Information Center

    Ryujin, Donald H.; And Others

    Social facilitation can be defined as the effect of an audience or coactors on performance. Research on social facilitation effects has produced some contradictory and confusing findings. Some studies have found that the presence of others enhances performance; other studies have found that the presence of an audience or coactors impairs…

  18. Facilitator Talk in EAP Reading Classes

    ERIC Educational Resources Information Center

    Wilson, Kate

    2008-01-01

    Current sociocultural perspectives on language learning call on teachers to reinvent themselves in ways which facilitate student learning rather than transmit knowledge. For teachers, this means adopting new roles, and acquiring a new repertoire of teacher talk. This paper aims to further the work on facilitator talk begun by Clifton (2006) and…

  19. Interaction Patterns and Facilitation of Peer Learning.

    ERIC Educational Resources Information Center

    Shaw, Marvin E.; And Others

    1979-01-01

    Data show that giving information to members of a group is more important in determining the perception by others that the person is facilitating group performance. Asking for information and opinions is more important in actual facilitation of group learning. Social-emotional support becomes important after initial phases of group interaction.…

  20. Robust Pedestrian Tracking and Recognition from FLIR Video: A Unified Approach via Sparse Coding

    PubMed Central

    Li, Xin; Guo, Rui; Chen, Chao

    2014-01-01

    Sparse coding is an emerging method that has been successfully applied to both robust object tracking and recognition in the vision literature. In this paper, we propose to explore a sparse coding-based approach toward joint object tracking-and-recognition and explore its potential in the analysis of forward-looking infrared (FLIR) video to support nighttime machine vision systems. A key technical contribution of this work is to unify existing sparse coding-based approaches toward tracking and recognition under the same framework, so that they can benefit from each other in a closed-loop. On the one hand, tracking the same object through temporal frames allows us to achieve improved recognition performance through dynamical updating of template/dictionary and combining multiple recognition results; on the other hand, the recognition of individual objects facilitates the tracking of multiple objects (i.e., walking pedestrians), especially in the presence of occlusion within a crowded environment. We report experimental results on both the CASIAPedestrian Database and our own collected FLIR video database to demonstrate the effectiveness of the proposed joint tracking-and-recognition approach. PMID:24961216

  1. Emotion recognition during cocaine intoxication.

    PubMed

    Kuypers, K P C; Steenbergen, L; Theunissen, E L; Toennes, S W; Ramaekers, J G

    2015-11-01

    Chronic or repeated cocaine use has been linked to impairments in social skills. It is not clear whether cocaine is responsible for this impairment or whether other factors, like polydrug use, distort the observed relation. We aimed to investigate this relation by means of a placebo-controlled experimental study. Additionally, associations between stressor-related activity (cortisol, cardiovascular parameters) induced by the biological stressor cocaine, and potential cocaine effects on emotion recognition were studied. Twenty-four healthy recreational cocaine users participated in this placebo-controlled within-subject study. Participants were tested between 1 and 2 h after treatment with oral cocaine (300 mg) or placebo. Emotion recognition of low and high intensity expressions of basic emotions (fear, anger, disgust, sadness, and happiness) was tested. Findings show that cocaine impaired recognition of negative emotions; this was mediated by the intensity of the presented emotions. When high intensity expressions of Anger and Disgust were shown, performance under influence of cocaine 'normalized' to placebo-like levels while it made identification of Sadness more difficult. The normalization of performance was most notable for participants with the largest cortisol responses in the cocaine condition compared to placebo. It was demonstrated that cocaine impairs recognition of negative emotions, depending on the intensity of emotion expression and cortisol response. PMID:26328908

  2. The Army word recognition system

    NASA Technical Reports Server (NTRS)

    Hadden, David R.; Haratz, David

    1977-01-01

    The application of speech recognition technology in the Army command and control area is presented. The problems associated with this program are described as well as as its relevance in terms of the man/machine interactions, voice inflexions, and the amount of training needed to interact with and utilize the automated system.

  3. Low-resolution gait recognition.

    PubMed

    Zhang, Junping; Pu, Jian; Chen, Changyou; Fleischer, Rudolf

    2010-08-01

    Unlike other biometric authentication methods, gait recognition is noninvasive and effective from a distance. However, the performance of gait recognition will suffer in the low-resolution (LR) case. Furthermore, when gait sequences are projected onto a nonoptimal low-dimensional subspace to reduce the data complexity, the performance of gait recognition will also decline. To deal with these two issues, we propose a new algorithm called superresolution with manifold sampling and backprojection (SRMS), which learns the high-resolution (HR) counterparts of LR test images from a collection of HR/LR training gait image patch pairs. Then, we incorporate SRMS into a new algorithm called multilinear tensor-based learning without tuning parameters (MTP) for LR gait recognition. Our contributions include the following: 1) With manifold sampling, the redundancy of gait image patches is remarkably decreased; thus, the superresolution procedure is more efficient and reasonable. 2) Backprojection guarantees that the learned HR gait images and the corresponding LR gait images can be more consistent. 3) The optimal subspace dimension for dimension reduction is automatically determined without introducing extra parameters. 4) Theoretical analysis of the algorithm shows that MTP converges. Experiments on the USF human gait database and the CASIA gait database show the increased efficiency of the proposed algorithm, compared with previous algorithms. PMID:20199936

  4. Enduring voice recognition in bonobos.

    PubMed

    Keenan, Sumir; Mathevon, Nicolas; Stevens, Jeroen M G; Guéry, Jean Pascal; Zuberbühler, Klaus; Levréro, Florence

    2016-01-01

    Long-term social recognition is vital for species with complex social networks, where familiar individuals can encounter one another after long periods of separation. For non-human primates who live in dense forest environments, visual access to one another is often limited, and recognition of social partners over distances largely depends on vocal communication. Vocal recognition after years of separation has never been reported in any great ape species, despite their complex societies and advanced social intelligence. Here we show that bonobos, Pan paniscus, demonstrate reliable vocal recognition of social partners, even if they have been separated for five years. We experimentally tested bonobos' responses to the calls of previous group members that had been transferred between captive groups. Despite long separations, subjects responded more intensely to familiar voices than to calls from unknown individuals - the first experimental evidence that bonobos can identify individuals utilising vocalisations even years after their last encounter. Our study also suggests that bonobos may cease to discriminate between familiar and unfamiliar individuals after a period of eight years, indicating that voice representations or interest could be limited in time in this species. PMID:26911199

  5. Output Interference in Recognition Memory

    ERIC Educational Resources Information Center

    Criss, Amy H.; Malmberg, Kenneth J.; Shiffrin, Richard M.

    2011-01-01

    Dennis and Humphreys (2001) proposed that interference in recognition memory arises solely from the prior contexts of the test word: Interference does not arise from memory traces of other words (from events prior to the study list or on the study list, and regardless of similarity to the test item). We evaluate this model using output…

  6. Enduring voice recognition in bonobos

    PubMed Central

    Keenan, Sumir; Mathevon, Nicolas; Stevens, Jeroen MG; Guéry, Jean Pascal; Zuberbühler, Klaus; Levréro, Florence

    2016-01-01

    Long-term social recognition is vital for species with complex social networks, where familiar individuals can encounter one another after long periods of separation. For non-human primates who live in dense forest environments, visual access to one another is often limited, and recognition of social partners over distances largely depends on vocal communication. Vocal recognition after years of separation has never been reported in any great ape species, despite their complex societies and advanced social intelligence. Here we show that bonobos, Pan paniscus, demonstrate reliable vocal recognition of social partners, even if they have been separated for five years. We experimentally tested bonobos’ responses to the calls of previous group members that had been transferred between captive groups. Despite long separations, subjects responded more intensely to familiar voices than to calls from unknown individuals - the first experimental evidence that bonobos can identify individuals utilising vocalisations even years after their last encounter. Our study also suggests that bonobos may cease to discriminate between familiar and unfamiliar individuals after a period of eight years, indicating that voice representations or interest could be limited in time in this species. PMID:26911199

  7. Emotion recognition during cocaine intoxication.

    PubMed

    Kuypers, K P C; Steenbergen, L; Theunissen, E L; Toennes, S W; Ramaekers, J G

    2015-11-01

    Chronic or repeated cocaine use has been linked to impairments in social skills. It is not clear whether cocaine is responsible for this impairment or whether other factors, like polydrug use, distort the observed relation. We aimed to investigate this relation by means of a placebo-controlled experimental study. Additionally, associations between stressor-related activity (cortisol, cardiovascular parameters) induced by the biological stressor cocaine, and potential cocaine effects on emotion recognition were studied. Twenty-four healthy recreational cocaine users participated in this placebo-controlled within-subject study. Participants were tested between 1 and 2 h after treatment with oral cocaine (300 mg) or placebo. Emotion recognition of low and high intensity expressions of basic emotions (fear, anger, disgust, sadness, and happiness) was tested. Findings show that cocaine impaired recognition of negative emotions; this was mediated by the intensity of the presented emotions. When high intensity expressions of Anger and Disgust were shown, performance under influence of cocaine 'normalized' to placebo-like levels while it made identification of Sadness more difficult. The normalization of performance was most notable for participants with the largest cortisol responses in the cocaine condition compared to placebo. It was demonstrated that cocaine impairs recognition of negative emotions, depending on the intensity of emotion expression and cortisol response.

  8. Face recognition for uncontrolled environments

    NASA Astrophysics Data System (ADS)

    Podilchuk, Christine; Hulbert, William; Flachsbart, Ralph; Barinov, Lev

    2010-04-01

    A new face recognition algorithm has been proposed which is robust to variations in pose, expression, illumination and occlusions such as sunglasses. The algorithm is motivated by the Edit Distance used to determine the similarity between strings of one dimensional data such as DNA and text. The key to this approach is how to extend the concept of an Edit Distance on one-dimensional data to two-dimensional image data. The algorithm is based on mapping one image into another and using the characteristics of the mapping to determine a two-dimensional Pictorial-Edit Distance or P-Edit Distance. We show how the properties of the mapping are similar to insertion, deletion and substitution errors defined in an Edit Distance. This algorithm is particularly well suited for face recognition in uncontrolled environments such as stand-off and other surveillance applications. We will describe an entire system designed for face recognition at a distance including face detection, pose estimation, multi-sample fusion of video frames and identification. Here we describe how the algorithm is used for face recognition at a distance, present some initial results and describe future research directions.(

  9. Method and System for Object Recognition Search

    NASA Technical Reports Server (NTRS)

    Duong, Tuan A. (Inventor); Duong, Vu A. (Inventor); Stubberud, Allen R. (Inventor)

    2012-01-01

    A method for object recognition using shape and color features of the object to be recognized. An adaptive architecture is used to recognize and adapt the shape and color features for moving objects to enable object recognition.

  10. Facilitated versus Non-Facilitated Online Case Discussions: Comparing Differences in Problem Space Coverage

    ERIC Educational Resources Information Center

    Ertmer, Peggy A.; Koehler, Adrie A.

    2015-01-01

    The facilitator plays a key role in guiding students' efforts during case discussions. However, few studies have compared differences in learning outcomes for students participating in facilitated versus non-facilitated discussions. In this research, we used "problem space coverage" as a learning measure to compare outcomes between…

  11. A propositional theory of recognition memory.

    PubMed

    Anderson, J R; Bower, G H

    1974-05-01

    This paper modifies the Anderson and Bower (1972) theory of recognition memory for words. A propositional representation is outlined for the contextual information underlying word recognition. Logical arguments are offered for preferring this representation over the undifferentiated associative representation used earlier. The propositional representation is used to interpret effects of verbal context upon recognition memory. The implications of these context effects are considered for two-process models of recall and recognition. PMID:21274765

  12. Using Questions To Facilitate Motor Skill Acquisition.

    ERIC Educational Resources Information Center

    Knight, G. William; And Others

    1997-01-01

    Describes a dental teaching strategy that promotes acquisition of psychomotor skills through use of metacognition and problem-solving. In five steps, questions are asked to guide the learner through a sequence of discriminations leading to recognition of problems and solutions. Clearly defined criteria in a sequence reflecting procedure are…

  13. 77 FR 9590 - Recognition and Accreditation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-17

    ...; ] DEPARTMENT OF JUSTICE 8 CFR Part 1292 RIN 1125-AA72 Recognition and Accreditation AGENCY: Executive Office... the recognition of organizations and accreditation of representatives who appear before EOIR. EOIR... discuss these regulations. The first meeting will be limited to a discussion of the recognition...

  14. Interaction between affordance and handedness recognition: a chronometric study

    PubMed Central

    Lameira, A.P.; Pereira, A.; Conde, E.; Gawryszewski, L.G.

    2015-01-01

    The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject's hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation. PMID:25714894

  15. Individual recognition through olfactory–auditory matching in lemurs

    PubMed Central

    Kulahci, Ipek G.; Drea, Christine M.; Rubenstein, Daniel I.; Ghazanfar, Asif A.

    2014-01-01

    Individual recognition can be facilitated by creating representations of familiar individuals, whereby information from signals in multiple sensory modalities become linked. Many vertebrate species use auditory–visual matching to recognize familiar conspecifics and heterospecifics, but we currently do not know whether representations of familiar individuals incorporate information from other modalities. Ring-tailed lemurs (Lemur catta) are highly visual, but also communicate via scents and vocalizations. To investigate the role of olfactory signals in multisensory recognition, we tested whether lemurs can recognize familiar individuals through matching scents and vocalizations. We presented lemurs with female scents that were paired with the contact call either of the female whose scent was presented or of another familiar female from the same social group. When the scent and the vocalization came from the same individual versus from different individuals, females showed greater interest in the scents, and males showed greater interest in both the scents and the vocalizations, suggesting that lemurs can recognize familiar females via olfactory–auditory matching. Because identity signals in lemur scents and vocalizations are produced by different effectors and often encountered at different times (uncoupled in space and time), this matching suggests lemurs form multisensory representations through a newly recognized sensory integration underlying individual recognition. PMID:24741013

  16. Recognition of Arabic Sign Language Alphabet Using Polynomial Classifiers

    NASA Astrophysics Data System (ADS)

    Assaleh, Khaled; Al-Rousan, M.

    2005-12-01

    Building an accurate automatic sign language recognition system is of great importance in facilitating efficient communication with deaf people. In this paper, we propose the use of polynomial classifiers as a classification engine for the recognition of Arabic sign language (ArSL) alphabet. Polynomial classifiers have several advantages over other classifiers in that they do not require iterative training, and that they are highly computationally scalable with the number of classes. Based on polynomial classifiers, we have built an ArSL system and measured its performance using real ArSL data collected from deaf people. We show that the proposed system provides superior recognition results when compared with previously published results using ANFIS-based classification on the same dataset and feature extraction methodology. The comparison is shown in terms of the number of misclassified test patterns. The reduction in the rate of misclassified patterns was very significant. In particular, we have achieved a 36% reduction of misclassifications on the training data and 57% on the test data.

  17. Individual recognition through olfactory-auditory matching in lemurs.

    PubMed

    Kulahci, Ipek G; Drea, Christine M; Rubenstein, Daniel I; Ghazanfar, Asif A

    2014-06-01

    Individual recognition can be facilitated by creating representations of familiar individuals, whereby information from signals in multiple sensory modalities become linked. Many vertebrate species use auditory-visual matching to recognize familiar conspecifics and heterospecifics, but we currently do not know whether representations of familiar individuals incorporate information from other modalities. Ring-tailed lemurs (Lemur catta) are highly visual, but also communicate via scents and vocalizations. To investigate the role of olfactory signals in multisensory recognition, we tested whether lemurs can recognize familiar individuals through matching scents and vocalizations. We presented lemurs with female scents that were paired with the contact call either of the female whose scent was presented or of another familiar female from the same social group. When the scent and the vocalization came from the same individual versus from different individuals, females showed greater interest in the scents, and males showed greater interest in both the scents and the vocalizations, suggesting that lemurs can recognize familiar females via olfactory-auditory matching. Because identity signals in lemur scents and vocalizations are produced by different effectors and often encountered at different times (uncoupled in space and time), this matching suggests lemurs form multisensory representations through a newly recognized sensory integration underlying individual recognition. PMID:24741013

  18. Recognition advantage of happy faces: tracing the neurocognitive processes.

    PubMed

    Calvo, Manuel G; Beltrán, David

    2013-09-01

    The present study aimed to identify the brain processes-and their time course-underlying the typical behavioral recognition advantage of happy facial expressions. To this end, we recorded EEG activity during an expression categorization task for happy, angry, fearful, sad, and neutral faces, and the correlation between event-related-potential (ERP) patterns and recognition performance was assessed. N170 (150-180 ms) was enhanced for angry, fearful and sad faces; N2 was reduced and early posterior negativity (EPN; both, 200-320 ms) was enhanced for happy and angry faces; P3b (350-450 ms) was reduced for happy and neutral faces; and slow positive wave (SPW; 700-800 ms) was reduced for happy faces. This reveals (a) an early processing (N170) of negative affective valence (i.e., angry, fearful, and sad), (b) discrimination (N2 and EPN) of affective intensity or arousal (i.e., angry and happy), and (c) facilitated categorization (P3b) and decision (SPW) due to expressive distinctiveness (i.e., happy). In addition, N2, EPN, P3b, and SPW were related to categorization accuracy and speed. This suggests that conscious expression recognition and the typical happy face advantage depend on encoding of expressive intensity and, especially, on later response selection, rather than on the early processing of affective valence.

  19. Facilitating LOS Debriefings: A Training Manual

    NASA Technical Reports Server (NTRS)

    McDonnell, Lori K.; Jobe, Kimberly K.; Dismukes, R. Key

    1997-01-01

    This manual is a practical guide to help airline instructors effectively facilitate debriefings of Line Oriented Simulations (LOS). It is based on a recently completed study of Line Oriented Flight Training (LOFT) debriefings at several U.S. airlines. This manual presents specific facilitation tools instructors can use to achieve debriefing objectives. The approach of the manual is to be flexible so it can be tailored to the individual needs of each airline. Part One clarifies the purpose and objectives of facilitation in the LOS setting. Part Two provides recommendations for clarifying roles and expectations and presents a model for organizing discussion. Part Tree suggests techniques for eliciting active crew participation and in-depth analysis and evaluation. Finally, in Part Four, these techniques are organized according to the facilitation model. Examples of how to effectively use the techniques are provided throughout, including strategies to try when the debriefing objectives are not being fully achieved.

  20. Dream Deprivation and Facilitation with Hypnosis

    ERIC Educational Resources Information Center

    Albert, Ira B.; Boone, Donald

    1975-01-01

    The present study attempted to deprive human subjects of dreaming through the administration of a posthypnotic suggestion and to increase or facilitate dreaming through a second suggestion that was used with another group of subjects. (Author/RK)

  1. 36 CFR 1194.5 - Equivalent facilitation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... COMPLIANCE BOARD ELECTRONIC AND INFORMATION TECHNOLOGY ACCESSIBILITY STANDARDS General § 1194.5 Equivalent facilitation. Nothing in this part is intended to prevent the use of designs or technologies as alternatives...

  2. Managing and facilitating innovation and nurse satisfaction.

    PubMed

    Weston, Marla J

    2009-01-01

    Behaviors and actions that foster innovation are complementary to those associated with managing and facilitating nurse satisfaction. These include creating an organizational climate that encourages the generation, sharing, and implementation of new ideas; managing with the skills to hire and retain competent and creative individuals; and establishing the infrastructure and processes to recognize and embed best and promising practices into the organization. The ability to innovate and to manage and facilitate nurse satisfaction is a necessary competency for organizational success. PMID:19893447

  3. Aminobenzohydrazide based colorimetric and 'turn-on' fluorescence chemosensor for selective recognition of fluoride.

    PubMed

    Anand, Thangaraj; Sivaraman, Gandhi; Iniya, Murugan; Siva, Ayyanar; Chellappa, Duraisamy

    2015-05-30

    Chemosensors based on aminobenzohydrazide Schiff bases bearing pyrene/anthracene as fluorophores have been designed and synthesized for F(-) ion recognition. The addition of fluoride ions to the receptors causes a dramatically observable colour change from pale yellow to brown/red. (1)H NMR studies confirm that the F(-) ion facilitates its recognition by forming hydrogen bond with hydrogens of amide and amine groups. Moreover these sensors have also been successfully applied to detection of fluoride ion in commercial tooth paste solution. PMID:25998453

  4. Integration of partial information for spoken and written sentence recognition by older listeners.

    PubMed

    Smith, Kimberly G; Fogerty, Daniel

    2016-06-01

    Older adults have difficulty understanding speech in challenging listening environments. Combining multisensory signals may facilitate speech recognition. This study measured recognition of interrupted spoken and written sentences by older adults for different preserved stimulus proportions. Unimodal performance was first examined when only interrupted text or speech stimuli were presented. Multimodal performance with concurrently presented text and speech stimuli was tested with delayed and simultaneous participant responses. Older listeners performed better in unimodal speech-only compared to text-only conditions across all proportions preserved. Performance was also better in delayed multimodal conditions. Comparison to a younger sample suggests age-related amodal processing declines.

  5. Visual similarity at encoding and retrieval in an item recognition task.

    PubMed

    Mate, Judit; Baqués, Josep

    2009-07-01

    The aim of this experiment was to examine the effects of shape similarity in visual working memory using a six alternative recognition task of Chinese characters. Shape similarity among items was manipulated at both encoding and retrieval in order to assess in which phase similarity impairs recognition to a greater degree. Results revealed that performance is particularly facilitated by high discriminability at retrieval but also by the presence of similar items at encoding, as similarity simplifies the global representation of the display and reduces memory load. Moreover, results provide further evidence that the classical similarity effect can be reversed in the visual domain when item memory (as opposed to order) is assessed.

  6. Categorical facilitation with equally discriminable colors.

    PubMed

    Witzel, Christoph; Gegenfurtner, Karl R

    2015-01-01

    This study investigates the impact of language on color perception. By categorical facilitation, we refer to an aspect of categorical perception, in which the linguistic distinction between categories affects color discrimination beyond the low-level, sensory sensitivity to color differences. According to this idea, discrimination performance for colors that cross a category border should be better than for colors that belong to the same category when controlling for low-level sensitivity. We controlled for sensitivity by using colors that were equally discriminable according to empirically measured discrimination thresholds. To test for categorical facilitation, we measured response times and error rates in a speeded discrimination task for suprathreshold stimuli. Robust categorical facilitation occurred for five out of six categories with a group of inexperienced observers, namely for pink, orange, yellow, green, and purple. Categorical facilitation was robust against individual variations of categories or the laterality of target presentation. However, contradictory effects occurred in the blue category, most probably reflecting the difficulty to control effects of sensory mechanisms at the green-blue boundary. Moreover, a group of observers who were highly familiar with the discrimination task did not show consistent categorical facilitation in the other five categories. This trained group had much faster response times than the inexperienced group without any speed-accuracy trade-off. Additional analyses suggest that categorical facilitation occurs when observers pay attention to the categorical distinction but not when they respond automatically based on sensory feed-forward information. PMID:26129860

  7. Lateralized processes in face recognition.

    PubMed

    Rhodes, G

    1985-05-01

    In this paper a model is presented in which face recognition is analysed into several stages, each of which may be independently lateralized. Evidence is reviewed which suggests that lateralization is important at all stages of processing a face. Early visuospatial processing, and the creation and comparison of facial representations, appear to be carried out more efficiently by the right hemisphere. Comparisons based on discrete, namable features of faces may yield a left hemisphere advantage. It is also proposed that faces may activate semantic information, including names, more efficiently in the left hemisphere. The model is useful in resolving inconsistencies in the degree and direction of asymmetries found in face-recognition tasks. Suggestions are also made for future research.

  8. Molecular Recognition and Ligand Association

    NASA Astrophysics Data System (ADS)

    Baron, Riccardo; McCammon, J. Andrew

    2013-04-01

    We review recent developments in our understanding of molecular recognition and ligand association, focusing on two major viewpoints: (a) studies that highlight new physical insight into the molecular recognition process and the driving forces determining thermodynamic signatures of binding and (b) recent methodological advances in applications to protein-ligand binding. In particular, we highlight the challenges posed by compensating enthalpic and entropic terms, competing solute and solvent contributions, and the relevance of complex configurational ensembles comprising multiple protein, ligand, and solvent intermediate states. As more complete physics is taken into account, computational approaches increase their ability to complement experimental measurements, by providing a microscopic, dynamic view of ensemble-averaged experimental observables. Physics-based approaches are increasingly expanding their power in pharmacology applications.

  9. Turbo Processing for Speech Recognition.

    PubMed

    Moon, Todd K; Gunther, Jacob H; Broadus, Cortnie; Hou, Wendy; Nelson, Nils

    2014-01-01

    Speech recognition is a classic example of a human/machine interface, typifying many of the difficulties and opportunities of human/machine interaction. In this paper, speech recognition is used as an example of applying turbo processing principles to the general problem of human/machine interface. Speech recognizers frequently involve a model representing phonemic information at a local level, followed by a language model representing information at a nonlocal level. This structure is analogous to the local (e.g., equalizer) and nonlocal (e.g., error correction decoding) elements common in digital communications. Drawing from the analogy of turbo processing for digital communications, turbo speech processing iteratively feeds back the output of the language model to be used as prior probabilities for the phonemic model. This analogy is developed here, and the performance of this turbo model is characterized by using an artificial language model. Using turbo processing, the relative error rate improves significantly, especially in high-noise settings.

  10. Immune recognition of protein antigens

    SciTech Connect

    Laver, W.G.; Air, G.M.

    1985-01-01

    This book contains 33 papers. Some of the titles are: Antigenic Structure of Influenze Virus Hemagglutinin; Germ-line and Somatic Diversity in the Antibody Response to the Influenza Virus A/PR/8/34 Hemagglutinin; Recognition of Cloned Influenza A Virus Gene Products by Cytotoxic T Lymphocytes; Antigenic Structure of the Influenza Virus N2 Neuraminidase; and The Molecular and Genetic Basis of Antigenic Variation in Gonococcal Pillin.

  11. Image processing for drawing recognition

    NASA Astrophysics Data System (ADS)

    Feyzkhanov, Rustem; Zhelavskaya, Irina

    2014-03-01

    The task of recognizing edges of rectangular structures is well known. Still, almost all of them work with static images and has no limit on work time. We propose application of conducting homography for the video stream which can be obtained from the webcam. We propose algorithm which can be successfully used for this kind of application. One of the main use cases of such application is recognition of drawings by person on the piece of paper before webcam.

  12. Face Recognition Incorporating Ancillary Information

    NASA Astrophysics Data System (ADS)

    Kim, Sang-Ki; Toh, Kar-Ann; Lee, Sangyoun

    2007-12-01

    Due to vast variations of extrinsic and intrinsic imaging conditions, face recognition remained to be a challenging computer vision problem even today. This is particularly true when the passive imaging approach is considered for robust applications. To advance existing recognition systems for face, numerous techniques and methods have been proposed to overcome the almost inevitable performance degradation due to external factors such as pose, expression, occlusion, and illumination. In particular, the recent part-based method has provided noticeable room for verification performance improvement based on the localized features which have good tolerance to variation of external conditions. The part-based method, however, does not really stretch the performance without incorporation of global information from the holistic method. In view of the need to fuse the local information and the global information in an adaptive manner for reliable recognition, in this paper we investigate whether such external factors can be explicitly estimated and be used to boost the verification performance during fusion of the holistic and part-based methods. Our empirical evaluations show noticeable performance improvement adopting the proposed method.

  13. Human recognition of familiar voices.

    PubMed

    Wenndt, Stanley J

    2016-08-01

    Recognizing familiar voices is something we do every day. In quiet environments, it is usually easy to recognize a familiar voice. In noisier environments, this can become a difficult task. This paper examines how robust listeners are at identifying familiar voices in noisy, changing environments and what factors may affect their recognition rates. While there is previous research addressing familiar speaker recognition, the research is limited due to the difficulty in obtaining appropriate data that eliminates speaker dependent traits, such as word choice, along with having corresponding listeners who are familiar with the speakers. The data used in this study were collected in such a fashion to mimic conversational, free-flow dialogue, but in a way to eliminate many variables such as word choice, intonation, or non-verbal cues. These data provide some of the most realistic test scenarios to-date for familiar speaker identification. A pure-tone hearing test was used to separate listeners into normal hearing and hearing impaired groups. It is hypothesized that the results of the Normal Hearing Group will be statistically better. Additionally, the aspect of familiar speaker recognition is addressed by having each listener rate his or her familiarity with each speaker. Two statistical approaches showed that the more familiar a listener is with a speaker, the more likely the listener will recognize the speaker. PMID:27586746

  14. Additive attacks on speaker recognition

    NASA Astrophysics Data System (ADS)

    Farrokh Baroughi, Alireza; Craver, Scott

    2014-02-01

    Speaker recognition is used to identify a speaker's voice from among a group of known speakers. A common method of speaker recognition is a classification based on cepstral coefficients of the speaker's voice, using a Gaussian mixture model (GMM) to model each speaker. In this paper we try to fool a speaker recognition system using additive noise such that an intruder is recognized as a target user. Our attack uses a mixture selected from a target user's GMM model, inverting the cepstral transformation to produce noise samples. In our 5 speaker data base, we achieve an attack success rate of 50% with a noise signal at 10dB SNR, and 95% by increasing noise power to 0dB SNR. The importance of this attack is its simplicity and flexibility: it can be employed in real time with no processing of an attacker's voice, and little computation is needed at the moment of detection, allowing the attack to be performed by a small portable device. For any target user, knowing that user's model or voice sample is sufficient to compute the attack signal, and it is enough that the intruder plays it while he/she is uttering to be classiffed as the victim.

  15. Fingerprint recognition using image processing

    NASA Astrophysics Data System (ADS)

    Dholay, Surekha; Mishra, Akassh A.

    2011-06-01

    Finger Print Recognition is concerned with the difficult task of matching the images of finger print of a person with the finger print present in the database efficiently. Finger print Recognition is used in forensic science which helps in finding the criminals and also used in authentication of a particular person. Since, Finger print is the only thing which is unique among the people and changes from person to person. The present paper describes finger print recognition methods using various edge detection techniques and also how to detect correct finger print using a camera images. The present paper describes the method that does not require a special device but a simple camera can be used for its processes. Hence, the describe technique can also be using in a simple camera mobile phone. The various factors affecting the process will be poor illumination, noise disturbance, viewpoint-dependence, Climate factors, and Imaging conditions. The described factor has to be considered so we have to perform various image enhancement techniques so as to increase the quality and remove noise disturbance of image. The present paper describe the technique of using contour tracking on the finger print image then using edge detection on the contour and after that matching the edges inside the contour.

  16. Visual recognition of permuted words

    NASA Astrophysics Data System (ADS)

    Rashid, Sheikh Faisal; Shafait, Faisal; Breuel, Thomas M.

    2010-02-01

    In current study we examine how letter permutation affects in visual recognition of words for two orthographically dissimilar languages, Urdu and German. We present the hypothesis that recognition or reading of permuted and non-permuted words are two distinct mental level processes, and that people use different strategies in handling permuted words as compared to normal words. A comparison between reading behavior of people in these languages is also presented. We present our study in context of dual route theories of reading and it is observed that the dual-route theory is consistent with explanation of our hypothesis of distinction in underlying cognitive behavior for reading permuted and non-permuted words. We conducted three experiments in lexical decision tasks to analyze how reading is degraded or affected by letter permutation. We performed analysis of variance (ANOVA), distribution free rank test, and t-test to determine the significance differences in response time latencies for two classes of data. Results showed that the recognition accuracy for permuted words is decreased 31% in case of Urdu and 11% in case of German language. We also found a considerable difference in reading behavior for cursive and alphabetic languages and it is observed that reading of Urdu is comparatively slower than reading of German due to characteristics of cursive script.

  17. Infant Visual Attention and Object Recognition

    PubMed Central

    Reynolds, Greg D.

    2015-01-01

    This paper explores the role visual attention plays in the recognition of objects in infancy. Research and theory on the development of infant attention and recognition memory are reviewed in three major sections. The first section reviews some of the major findings and theory emerging from a rich tradition of behavioral research utilizing preferential looking tasks to examine visual attention and recognition memory in infancy. The second section examines research utilizing neural measures of attention and object recognition in infancy as well as research on brain-behavior relations in the early development of attention and recognition memory. The third section addresses potential areas of the brain involved in infant object recognition and visual attention. An integrated synthesis of some of the existing models of the development of visual attention is presented which may account for the observed changes in behavioral and neural measures of visual attention and object recognition that occur across infancy. PMID:25596333

  18. Fluency and response speed in recognition judgments.

    PubMed

    Poldrack, R A; Logan, G D

    1997-01-01

    Previous research has suggested that perceptual fluency can contribute to recognition judgments. In this study, we examined whether fluency in recognition is based upon the speed of preceding operations, as suggested by studies of perceptual fluency. Subjects studied items in both lexical decision and naming tasks, and were then tested on two blocks of lexical decision trials with probe recognition trials. Jacoby's process dissociation procedure was used, and results from this procedure suggested that recognition judgments in the task were based largely upon familiarity. However, the estimated discriminability available from response time distributions was significantly less than the observed recognition discriminability. Simulated memory operating characteristics confirmed this under determination of recognition by response times. The results demonstrate, contrary to previous suggestions, that fluency in recognition is not based upon speed.

  19. Automatic speech recognition technology development at ITT Defense Communications Division

    NASA Technical Reports Server (NTRS)

    White, George M.

    1977-01-01

    An assessment of the applications of automatic speech recognition to defense communication systems is presented. Future research efforts include investigations into the following areas: (1) dynamic programming; (2) recognition of speech degraded by noise; (3) speaker independent recognition; (4) large vocabulary recognition; (5) word spotting and continuous speech recognition; and (6) isolated word recognition.

  20. Foreign language comprehension achievement: insights from the cognate facilitation effect

    PubMed Central

    Casaponsa, Aina; Antón, Eneko; Pérez, Alejandro; Duñabeitia, Jon A.

    2015-01-01

    Numerous studies have shown that the native language influences foreign word recognition and that this influence is modulated by the proficiency in the non-native language. Here we explored how the degree of reliance on cross-language similarity (as measured by the cognate facilitation effect) together with other domain-general cognitive factors contribute to reading comprehension achievement in a non-native language at different stages of the learning process. We tested two groups of native speakers of Spanish learning English at elementary and intermediate levels in an academic context. A regression model approach showed that domain-general cognitive skills are good predictors of second language reading achievement independently of the level of proficiency. Critically, we found that individual differences in the degree of reliance on the native language predicted foreign language reading achievement, showing a markedly different pattern between proficiency groups. At lower levels of proficiency the cognate facilitation effect was positively related with reading achievement, while this relation became negative at intermediate levels of foreign language learning. We conclude that the link between native- and foreign-language lexical representations helps participants at initial stages of the learning process, whereas it is no longer the case at intermediate levels of proficiency, when reliance on cross-language similarity is inversely related to successful non-native reading achievement. Thus, at intermediate levels of proficiency strong and direct mappings from the non-native lexical forms to semantic concepts are needed to achieve good non-native reading comprehension, in line with the premises of current models of bilingual lexico-semantic organization. PMID:25999899

  1. Foreign language comprehension achievement: insights from the cognate facilitation effect.

    PubMed

    Casaponsa, Aina; Antón, Eneko; Pérez, Alejandro; Duñabeitia, Jon A

    2015-01-01

    Numerous studies have shown that the native language influences foreign word recognition and that this influence is modulated by the proficiency in the non-native language. Here we explored how the degree of reliance on cross-language similarity (as measured by the cognate facilitation effect) together with other domain-general cognitive factors contribute to reading comprehension achievement in a non-native language at different stages of the learning process. We tested two groups of native speakers of Spanish learning English at elementary and intermediate levels in an academic context. A regression model approach showed that domain-general cognitive skills are good predictors of second language reading achievement independently of the level of proficiency. Critically, we found that individual differences in the degree of reliance on the native language predicted foreign language reading achievement, showing a markedly different pattern between proficiency groups. At lower levels of proficiency the cognate facilitation effect was positively related with reading achievement, while this relation became negative at intermediate levels of foreign language learning. We conclude that the link between native- and foreign-language lexical representations helps participants at initial stages of the learning process, whereas it is no longer the case at intermediate levels of proficiency, when reliance on cross-language similarity is inversely related to successful non-native reading achievement. Thus, at intermediate levels of proficiency strong and direct mappings from the non-native lexical forms to semantic concepts are needed to achieve good non-native reading comprehension, in line with the premises of current models of bilingual lexico-semantic organization.

  2. Acquired prosopagnosia without word recognition deficits.

    PubMed

    Susilo, Tirta; Wright, Victoria; Tree, Jeremy J; Duchaine, Bradley

    2015-01-01

    It has long been suggested that face recognition relies on specialized mechanisms that are not involved in visual recognition of other object categories, including those that require expert, fine-grained discrimination at the exemplar level such as written words. But according to the recently proposed many-to-many theory of object recognition (MTMT), visual recognition of faces and words are carried out by common mechanisms [Behrmann, M., & Plaut, D. C. ( 2013 ). Distributed circuits, not circumscribed centers, mediate visual recognition. Trends in Cognitive Sciences, 17, 210-219]. MTMT acknowledges that face and word recognition are lateralized, but posits that the mechanisms that predominantly carry out face recognition still contribute to word recognition and vice versa. MTMT makes a key prediction, namely that acquired prosopagnosics should exhibit some measure of word recognition deficits. We tested this prediction by assessing written word recognition in five acquired prosopagnosic patients. Four patients had lesions limited to the right hemisphere while one had bilateral lesions with more pronounced lesions in the right hemisphere. The patients completed a total of seven word recognition tasks: two lexical decision tasks and five reading aloud tasks totalling more than 1200 trials. The performances of the four older patients (3 female, age range 50-64 years) were compared to those of 12 older controls (8 female, age range 56-66 years), while the performances of the younger prosopagnosic (male, 31 years) were compared to those of 14 younger controls (9 female, age range 20-33 years). We analysed all results at the single-patient level using Crawford's t-test. Across seven tasks, four prosopagnosics performed as quickly and accurately as controls. Our results demonstrate that acquired prosopagnosia can exist without word recognition deficits. These findings are inconsistent with a key prediction of MTMT. They instead support the hypothesis that face

  3. Acquired prosopagnosia without word recognition deficits.

    PubMed

    Susilo, Tirta; Wright, Victoria; Tree, Jeremy J; Duchaine, Bradley

    2015-01-01

    It has long been suggested that face recognition relies on specialized mechanisms that are not involved in visual recognition of other object categories, including those that require expert, fine-grained discrimination at the exemplar level such as written words. But according to the recently proposed many-to-many theory of object recognition (MTMT), visual recognition of faces and words are carried out by common mechanisms [Behrmann, M., & Plaut, D. C. ( 2013 ). Distributed circuits, not circumscribed centers, mediate visual recognition. Trends in Cognitive Sciences, 17, 210-219]. MTMT acknowledges that face and word recognition are lateralized, but posits that the mechanisms that predominantly carry out face recognition still contribute to word recognition and vice versa. MTMT makes a key prediction, namely that acquired prosopagnosics should exhibit some measure of word recognition deficits. We tested this prediction by assessing written word recognition in five acquired prosopagnosic patients. Four patients had lesions limited to the right hemisphere while one had bilateral lesions with more pronounced lesions in the right hemisphere. The patients completed a total of seven word recognition tasks: two lexical decision tasks and five reading aloud tasks totalling more than 1200 trials. The performances of the four older patients (3 female, age range 50-64 years) were compared to those of 12 older controls (8 female, age range 56-66 years), while the performances of the younger prosopagnosic (male, 31 years) were compared to those of 14 younger controls (9 female, age range 20-33 years). We analysed all results at the single-patient level using Crawford's t-test. Across seven tasks, four prosopagnosics performed as quickly and accurately as controls. Our results demonstrate that acquired prosopagnosia can exist without word recognition deficits. These findings are inconsistent with a key prediction of MTMT. They instead support the hypothesis that face

  4. The use of self-generation procedures facilitates verbal memory in individuals with seizure disorders.

    PubMed

    Schefft, Bruce K; Dulay, Mario F; Fargo, Jamison D; Szaflarski, Jerzy P; Yeh, Hwa-shain; Privitera, Michael D

    2008-07-01

    The efficacy of a self-generation encoding procedure in facilitating the encoding and retrieval of verbal memories was compared with the didactic presentation of information in individuals with seizure disorders. Through a within-subject design, 87 patients (25 left temporal seizure onset, 29 right temporal, 8 frontal, and 25 psychogenic nonepileptic seizures) received a self-generation learning condition and a didactic learning condition and were subsequently tested for verbal paired associate free recall, cued recall, and recognition memory. All patient groups benefited from the use of the self-generation condition relative to the didactic condition. Better performance occurred with the self-generation procedure for cued recall and recognition memory test performance, but not free recall. Individuals with a left temporal seizure onset (patients with the poorest memory performance on the didactic condition) benefited the most from the self-generation condition. A memory encoding strategy that actively involves patient participation enhances memory performance. PMID:18343201

  5. Ethanol facilitation of short-term memory in adult rats with a disturbed circadian cycle.

    PubMed

    Mikolajczak, P; Okulicz-Kozaryn, I; Nowaczyk, M; Kaminska, E

    2001-01-01

    The aim of this study was to evaluate the effect of 3-month ethanol treatment on olfactory social memory test performance using two inter-exposure intervals [30 min: short-term recognition (STR); or 120 min: long-term recognition (LTR)] in adult rats with a disturbed circadian cycle (DCC). Ethanol treatment both in ethanol-preferring and -non-preferring groups improved the STR task compared to control rats. However, LTR procedure triggered the opposite tendency. Moreover, no differences between control rats with DCC and those with normal diurnal rhythm in STR and LTR paradigms were observed. Our results suggest that, under some conditions, alcohol facilitates short-term memory in adult rats. PMID:11468127

  6. Understanding gender bias in face recognition: effects of divided attention at encoding.

    PubMed

    Palmer, Matthew A; Brewer, Neil; Horry, Ruth

    2013-03-01

    Prior research has demonstrated a female own-gender bias in face recognition, with females better at recognizing female faces than male faces. We explored the basis for this effect by examining the effect of divided attention during encoding on females' and males' recognition of female and male faces. For female participants, divided attention impaired recognition performance for female faces to a greater extent than male faces in a face recognition paradigm (Study 1; N=113) and an eyewitness identification paradigm (Study 2; N=502). Analysis of remember-know judgments (Study 2) indicated that divided attention at encoding selectively reduced female participants' recollection of female faces at test. For male participants, divided attention selectively reduced recognition performance (and recollection) for male stimuli in Study 2, but had similar effects on recognition of male and female faces in Study 1. Overall, the results suggest that attention at encoding contributes to the female own-gender bias by facilitating the later recollection of female faces.

  7. Lateral and Medial Ventral Occipitotemporal Regions Interact During the Recognition of Images Revealed from Noise

    PubMed Central

    Nordhjem, Barbara; Ćurčić-Blake, Branislava; Meppelink, Anne Marthe; Renken, Remco J.; de Jong, Bauke M.; Leenders, Klaus L.; van Laar, Teus; Cornelissen, Frans W.

    2016-01-01

    Several studies suggest different functional roles for the medial and the lateral sections of the ventral visual cortex in object recognition. Texture and surface information is processed in medial sections, while shape information is processed in lateral sections. This begs the question whether and how these functionally specialized sections interact with each other and with early visual cortex to facilitate object recognition. In the current research, we set out to answer this question. In an fMRI study, 13 subjects viewed and recognized images of objects and animals that were gradually revealed from noise while their brains were being scanned. We applied dynamic causal modeling (DCM)—a method to characterize network interactions—to determine the modulatory effect of object recognition on a network comprising the primary visual cortex (V1), the lingual gyrus (LG) in medial ventral cortex and the lateral occipital cortex (LO). We found that object recognition modulated the bilateral connectivity between LG and LO. Moreover, the feed-forward connectivity from V1 to LG and LO was modulated, while there was no evidence for feedback from these regions to V1 during object recognition. In particular, the interaction between medial and lateral areas supports a framework in which visual recognition of objects is achieved by networked regions that integrate information on image statistics, scene content and shape—rather than by a single categorically specialized region—within the ventral visual cortex. PMID:26778997

  8. From pauses to clauses: prosody facilitates learning of syntactic constituency.

    PubMed

    Hawthorne, Kara; Gerken, LouAnn

    2014-11-01

    Learning to parse the speech stream into syntactic constituents is a crucial prerequisite to adult-like sentence comprehension, and prosody is one source of information that could be used for this task. To test the role of prosody in facilitating constituent learning, 19-month-olds were familiarized with non-word sentences with 1-clause (ABCDEF) or 2-clause (ABC, DEF) prosody and were then tested on sentences that represent a grammatical (DEF, ABC) or ungrammatical (EFA, BCD) 'movement' of the clauses from the 2-clause familiarization sentences. If infants in the 2-clause group are able to use prosody to group words into cohesive chunks, they should discriminate between grammatical and ungrammatical movements in the test items, even though the test sentences have a new prosodic contour. The 1-clause, control, group should not discriminate. Results support these predictions and suggest that infants treat prosodically-grouped words as more cohesive and constituent-like than words that straddle a prosodic boundary. A follow-up experiment suggests that these results do not merely reflect recognition of words in boundary positions or acoustic similarity of words across the familiarization and test phases.

  9. Chromatin remodeling facilitates DNA incision in UV-damaged nucleosomes.

    PubMed

    Lee, Kyungeun; Kim, Deok Ryong; Ahn, Byungchan

    2004-08-31

    The DNA repair machinery must locate and repair DNA damage all over the genome. As nucleosomes inhibit DNA repair in vitro, it has been suggested that chromatin remodeling might be required for efficient repair in vivo. To investigate a possible contribution of nucleosome dynamics and chromatin remodeling to the repair of UV-photoproducts in nucleosomes, we examined the effect of a chromatin remodeling complex on the repair of UV-lesions by Micrococcus luteus UV endonuclease (ML-UV endo) and T4-endonuclease V (T4-endoV) in reconstituted mononucleosomes positioned at one end of a 175-bp long DNA fragment. Repair by ML-UV endo and T4-endoV was inefficient in mononucleosomes compared with naked DNA. However, the human nucleosome remodeling complex, hSWI/SNF, promoted more homogeneous repair by ML-UV endo and T4-endo V in reconstituted nucleosomes. This result suggests that recognition of DNA damage could be facilitated by a fluid state of the chromatin resulting from chromatin remodeling activities. PMID:15359130

  10. GUI to Facilitate Research on Biological Damage from Radiation

    NASA Technical Reports Server (NTRS)

    Cucinotta, Frances A.; Ponomarev, Artem Lvovich

    2010-01-01

    A graphical-user-interface (GUI) computer program has been developed to facilitate research on the damage caused by highly energetic particles and photons impinging on living organisms. The program brings together, into one computational workspace, computer codes that have been developed over the years, plus codes that will be developed during the foreseeable future, to address diverse aspects of radiation damage. These include codes that implement radiation-track models, codes for biophysical models of breakage of deoxyribonucleic acid (DNA) by radiation, pattern-recognition programs for extracting quantitative information from biological assays, and image-processing programs that aid visualization of DNA breaks. The radiation-track models are based on transport models of interactions of radiation with matter and solution of the Boltzmann transport equation by use of both theoretical and numerical models. The biophysical models of breakage of DNA by radiation include biopolymer coarse-grained and atomistic models of DNA, stochastic- process models of deposition of energy, and Markov-based probabilistic models of placement of double-strand breaks in DNA. The program is designed for use in the NT, 95, 98, 2000, ME, and XP variants of the Windows operating system.

  11. Smell facilitates auditory contagious yawning in stranger rats.

    PubMed

    Moyaho, Alejandro; Rivas-Zamudio, Xaman; Ugarte, Araceli; Eguibar, José R; Valencia, Jaime

    2015-01-01

    Most vertebrates yawn in situations ranging from relaxation to tension, but only humans and other primate species that show mental state attribution skills have been convincingly shown to display yawn contagion. Whether complex forms of empathy are necessary for yawn contagion to occur is still unclear. As empathy is a phylogenetically continuous trait, simple forms of empathy, such as emotional contagion, might be sufficient for non-primate species to show contagious yawning. In this study, we exposed pairs of male rats, which were selected for high yawning, with each other through a perforated wall and found that olfactory cues stimulated yawning, whereas visual cues inhibited it. Unexpectedly, cage-mate rats failed to show yawn contagion, although they did show correlated emotional reactivity. In contrast, stranger rats showed auditory contagious yawning and greater rates of smell-facilitated auditory contagious yawning, although they did not show correlated emotional reactivity. Strikingly, they did not show contagious yawning to rats from a low-yawning strain. These findings indicate that contagious yawning may be a widespread trait amongst vertebrates and that mechanisms other than empathy may be involved. We suggest that a communicatory function of yawning may be the mechanism responsible for yawn contagion in rats, as contagiousness was strain-specific and increased with olfactory cues, which are involved in mutual recognition.

  12. Phylogenetic analysis and expression profiling of the pattern recognition receptors: Insights into molecular recognition of invading pathogens in Manduca sexta.

    PubMed

    Zhang, Xiufeng; He, Yan; Cao, Xiaolong; Gunaratna, Ramesh T; Chen, Yun-ru; Blissard, Gary; Kanost, Michael R; Jiang, Haobo

    2015-07-01

    Pattern recognition receptors (PRRs) detect microbial pathogens and trigger innate immune responses. Previous biochemical studies have elucidated the physiological functions of eleven PRRs in Manduca sexta but our understanding of the recognition process is still limited, lacking genomic perspectives. While 34 C-type lectin-domain proteins and 16 Toll-like receptors are reported in the companion papers, we present here 120 other putative PRRs identified through the genome annotation. These include 76 leucine-rich repeat (LRR) proteins, 14 peptidoglycan recognition proteins, 6 EGF/Nim-domain proteins, 5 β-1,3-glucanase-related proteins, 4 galectins, 4 fibrinogen-related proteins, 3 thioester proteins, 5 immunoglobulin-domain proteins, 2 hemocytins, and 1 Reeler. Sequence alignment and phylogenetic analysis reveal the evolution history of a diverse repertoire of proteins for pathogen recognition. While functions of insect LRR proteins are mostly unknown, their structure diversification is phenomenal: In addition to the Toll homologs, 22 LRR proteins with a signal peptide are expected to be secreted; 18 LRR proteins lacking signal peptides may be cytoplasmic; 36 LRRs with a signal peptide and a transmembrane segment may be non-Toll receptors on the surface of cells. Expression profiles of the 120 genes in 52 tissue samples reflect complex regulation in various developmental stages and physiological states, including some likely by Rel family transcription factors via κB motifs in the promoter regions. This collection of information is expected to facilitate future biochemical studies detailing their respective roles in this model insect. PMID:25701384

  13. Physically facilitating drug-delivery systems

    PubMed Central

    Rodriguez-Devora, Jorge I; Ambure, Sunny; Shi, Zhi-Dong; Yuan, Yuyu; Sun, Wei; Xu, Tao

    2012-01-01

    Facilitated/modulated drug-delivery systems have emerged as a possible solution for delivery of drugs of interest to pre-allocated sites at predetermined doses for predefined periods of time. Over the past decade, the use of different physical methods and mechanisms to mediate drug release and delivery has grown significantly. This emerging area of research has important implications for development of new therapeutic drugs for efficient treatments. This review aims to introduce and describe different modalities of physically facilitating drug-delivery systems that are currently in use for cancer and other diseases therapy. In particular, delivery methods based on ultrasound, electrical, magnetic and photo modulations are highlighted. Current uses and areas of improvement for these different physically facilitating drug-delivery systems are discussed. Furthermore, the main advantages and drawbacks of these technologies reviewed are compared. The review ends with a speculative viewpoint of how research is expected to evolve in the upcoming years. PMID:22485192

  14. Elaboration over a Discourse Facilitates Retrieval in Sentence Processing.

    PubMed

    Troyer, Melissa; Hofmeister, Philip; Kutas, Marta

    2016-01-01

    Language comprehension requires access to stored knowledge and the ability to combine knowledge in new, meaningful ways. Previous work has shown that processing linguistically more complex expressions ('Texas cattle rancher' vs. 'rancher') leads to slow-downs in reading during initial processing, possibly reflecting effort in combining information. Conversely, when this information must subsequently be retrieved (as in filler-gap constructions), processing is facilitated for more complex expressions, possibly because more semantic cues are available during retrieval. To follow up on this hypothesis, we tested whether information distributed across a short discourse can similarly provide effective cues for retrieval. Participants read texts introducing two referents (e.g., two senators), one of whom was described in greater detail than the other (e.g., 'The Democrat had voted for one of the senators, and the Republican had voted for the other, a man from Ohio who was running for president'). The final sentence (e.g., 'The senator who the {Republican/Democrat}had voted for…') contained a relative clause picking out either the Many-Cue referent (with 'Republican') or the One-Cue referent (with 'Democrat'). We predicted facilitated retrieval (faster reading times) for the Many-Cue condition at the verb region ('had voted for'), where readers could understand that 'The senator' is the object of the verb. As predicted, this pattern was observed at the retrieval region and continued throughout the rest of the sentence. Participants also completed the Author/Magazine Recognition Tests (ART/MRT; Stanovich and West, 1989), providing a proxy for world knowledge. Since higher ART/MRT scores may index (a) greater experience accessing relevant knowledge and/or (b) richer/more highly structured representations in semantic memory, we predicted it would be positively associated with effects of elaboration on retrieval. We did not observe the predicted interaction between ART

  15. Elaboration over a Discourse Facilitates Retrieval in Sentence Processing.

    PubMed

    Troyer, Melissa; Hofmeister, Philip; Kutas, Marta

    2016-01-01

    Language comprehension requires access to stored knowledge and the ability to combine knowledge in new, meaningful ways. Previous work has shown that processing linguistically more complex expressions ('Texas cattle rancher' vs. 'rancher') leads to slow-downs in reading during initial processing, possibly reflecting effort in combining information. Conversely, when this information must subsequently be retrieved (as in filler-gap constructions), processing is facilitated for more complex expressions, possibly because more semantic cues are available during retrieval. To follow up on this hypothesis, we tested whether information distributed across a short discourse can similarly provide effective cues for retrieval. Participants read texts introducing two referents (e.g., two senators), one of whom was described in greater detail than the other (e.g., 'The Democrat had voted for one of the senators, and the Republican had voted for the other, a man from Ohio who was running for president'). The final sentence (e.g., 'The senator who the {Republican/Democrat}had voted for…') contained a relative clause picking out either the Many-Cue referent (with 'Republican') or the One-Cue referent (with 'Democrat'). We predicted facilitated retrieval (faster reading times) for the Many-Cue condition at the verb region ('had voted for'), where readers could understand that 'The senator' is the object of the verb. As predicted, this pattern was observed at the retrieval region and continued throughout the rest of the sentence. Participants also completed the Author/Magazine Recognition Tests (ART/MRT; Stanovich and West, 1989), providing a proxy for world knowledge. Since higher ART/MRT scores may index (a) greater experience accessing relevant knowledge and/or (b) richer/more highly structured representations in semantic memory, we predicted it would be positively associated with effects of elaboration on retrieval. We did not observe the predicted interaction between ART

  16. Elaboration over a Discourse Facilitates Retrieval in Sentence Processing

    PubMed Central

    Troyer, Melissa; Hofmeister, Philip; Kutas, Marta

    2016-01-01

    Language comprehension requires access to stored knowledge and the ability to combine knowledge in new, meaningful ways. Previous work has shown that processing linguistically more complex expressions (‘Texas cattle rancher’ vs. ‘rancher’) leads to slow-downs in reading during initial processing, possibly reflecting effort in combining information. Conversely, when this information must subsequently be retrieved (as in filler-gap constructions), processing is facilitated for more complex expressions, possibly because more semantic cues are available during retrieval. To follow up on this hypothesis, we tested whether information distributed across a short discourse can similarly provide effective cues for retrieval. Participants read texts introducing two referents (e.g., two senators), one of whom was described in greater detail than the other (e.g., ‘The Democrat had voted for one of the senators, and the Republican had voted for the other, a man from Ohio who was running for president’). The final sentence (e.g., ‘The senator who the {Republican/Democrat}had voted for…’) contained a relative clause picking out either the Many-Cue referent (with ‘Republican’) or the One-Cue referent (with ‘Democrat’). We predicted facilitated retrieval (faster reading times) for the Many-Cue condition at the verb region (‘had voted for’), where readers could understand that ‘The senator’ is the object of the verb. As predicted, this pattern was observed at the retrieval region and continued throughout the rest of the sentence. Participants also completed the Author/Magazine Recognition Tests (ART/MRT; Stanovich and West, 1989), providing a proxy for world knowledge. Since higher ART/MRT scores may index (a) greater experience accessing relevant knowledge and/or (b) richer/more highly structured representations in semantic memory, we predicted it would be positively associated with effects of elaboration on retrieval. We did not observe the

  17. Facilitation: An Essential Ingredient in Online Coursework

    NASA Astrophysics Data System (ADS)

    Ristvey, J.; Bogner, D.

    2003-12-01

    Mid-continent Research for Education and Learning (McREL) partnered with the Colorado School of Mines (CSM) to offer the ESSEA Earth System Science Online Course for Middle School Teachers during the 2002-2003 school year. During the two semesters that the course was offered, we were able to retain 75% of our enrollees. We found that course facilitation was the key ingredient in retaining this large number of students-who are not only scattered across the U.S., but around the world-in a rigorous online course. In this poster session, we will share what we have learned about online facilitation as part of this course, and how this knowledge might translate into other online coursework. Online facilitation begins as soon as a student enrolls in the course. When a student registers online or at CSM, McREL receives notification and then sends course materials and e-mail and written confirmation to the enrollee within 24 hours. This sets the tone for the type of communications that students can expect during the 16-week course. McREL facilitators know how time consuming monitoring participant progress can be, but feel strongly about its importance when facilitating learners who are working in small groups and are completing independent research. Timely monitoring of discussion spaces and e-mail messages is essential to maintaining a high student-retention rate. Kearsley (2000) confirms this when he states that, "the most important role of the instructor in online classes is to ensure that there is a high degree of interactivity and participation." In the ESSEA courses, the isolation of students working independently on classroom applications and reflection is balanced with group construction of interactions and causal chains. Each step of the way facilitators use guided questioning in group discussion sessions and serve as a mentor when participants develop individualized classroom assignments, giving participants the opportunity to apply what they have learned in a

  18. Effect of membrane mimicking environment on the conformation of a pore-forming (xSxG)6 peptide.

    PubMed

    Thundimadathil, Jyothi; Roeske, Roger W; Guo, Lili

    2006-01-01

    The mechanism of membrane interaction by beta-sheet peptides is important to understand fundamental principles of folding of beta-barrel proteins and various beta-amyloid proteins. Here, we examined the conformational characteristics of a porin-like channel forming (xSxG)(6) peptide in solution and membrane-mimicking environments (CD and ATR-IR) to understand the structural changes of the peptide during membrane association and channel formation. A comparison of the peptide conformations in different microenvironments showed that beta-sheet formation is enhanced in membrane-mimicking liposomes and SDS-micelles. The lipid-induced beta-sheet formation was confirmed by the formation of a characteristic beta-sheet structure on mixing a methanolic solution of the peptide (partially folded) with preformed liposomes. The amphipathicity of the peptide; increased hydrogen bonding, hydrophilicity, and reduction in dimensionality of the membrane surface; membrane-peptide interaction-forces; and presence of flexible glycines might facilitate beta-sheet formation in membranes. Though the CD spectra of both the peptide-bound and peptide-incorporated lipids are reminiscent of a beta-sheet structure, a significant variation in the peak positions of the two beta-sheet structures was noticed. The channel characteristics of (xSxG)(6) in the presence of low ionic strength solutions of NEt(3)BzCl and glucosammonium chloride are comparable to those reported under high ionic strength solutions. Altogether the data suggest that the channel formation by (xSxG)(6) proceeds via beta-sheet aggregate formation at the membrane surface, beta-sheet insertion, and rearrangement into a beta-barrel-like structure. The beta-barrel-like channel formation most likely arises from a sequence similarity to beta-barrel porins whereas the lipid-induced beta-sheet formation is governed by the above-mentioned factors.

  19. Crozier’s paradox revisited: maintenance of genetic recognition systems by disassortative mating

    PubMed Central

    2013-01-01

    Background Organisms are predicted to behave more favourably towards relatives, and kin-biased cooperation has been found in all domains of life from bacteria to vertebrates. Cooperation based on genetic recognition cues is paradoxical because it disproportionately benefits individuals with common phenotypes, which should erode the required cue polymorphism. Theoretical models suggest that many recognition loci likely have some secondary function that is subject to diversifying selection, keeping them variable. Results Here, we use individual-based simulations to investigate the hypothesis that the dual use of recognition cues to facilitate social behaviour and disassortative mating (e.g. for inbreeding avoidance) can maintain cue diversity over evolutionary time. Our model shows that when organisms mate disassortatively with respect to their recognition cues, cooperation and recognition locus diversity can persist at high values, especially when outcrossed matings produce more surviving offspring. Mating system affects cue diversity via at least four distinct mechanisms, and its effects interact with other parameters such as population structure. Also, the attrition of cue diversity is less rapid when cooperation does not require an exact cue match. Using a literature review, we show that there is abundant empirical evidence that heritable recognition cues are simultaneously used in social and sexual behaviour. Conclusions Our models show that mate choice is one possible resolution of the paradox of genetic kin recognition, and the literature review suggests that genetic recognition cues simultaneously inform assortative cooperation and disassortative mating in a large range of taxa. However, direct evidence is scant and there is substantial scope for future work. PMID:24070498

  20. Governing through Non/Recognition: The Missing "R" in the PLAR for Immigrant Professionals in Canada and Sweden

    ERIC Educational Resources Information Center

    Andersson, Per; Guo, Shibao

    2009-01-01

    Despite claims that prior learning assessment and recognition (PLAR) can act as a transformative social mechanism and a means of social inclusion, this study reports that PLAR has become a serious barrier to adult learning rather than a facilitator. Drawing from Foucault's concept of governmentality, the study examines the difficulties that…

  1. Face Processing: Models For Recognition

    NASA Astrophysics Data System (ADS)

    Turk, Matthew A.; Pentland, Alexander P.

    1990-03-01

    The human ability to process faces is remarkable. We can identify perhaps thousands of faces learned throughout our lifetime and read facial expression to understand such subtle qualities as emotion. These skills are quite robust, despite sometimes large changes in the visual stimulus due to expression, aging, and distractions such as glasses or changes in hairstyle or facial hair. Computers which model and recognize faces will be useful in a variety of applications, including criminal identification, human-computer interface, and animation. We discuss models for representing faces and their applicability to the task of recognition, and present techniques for identifying faces and detecting eye blinks.

  2. Speech recognition technology: a critique.

    PubMed Central

    Levinson, S E

    1995-01-01

    This paper introduces the session on advanced speech recognition technology. The two papers comprising this session argue that current technology yields a performance that is only an order of magnitude in error rate away from human performance and that incremental improvements will bring us to that desired level. I argue that, to the contrary, present performance is far removed from human performance and a revolution in our thinking is required to achieve the goal. It is further asserted that to bring about the revolution more effort should be expended on basic research and less on trying to prematurely commercialize a deficient technology. PMID:7479808

  3. Effect of colour pop-out on the recognition of letters in crowding conditions.

    PubMed

    Põder, Endel

    2007-11-01

    The crowding effect of adjacent objects on the recognition of a target can be reduced when target and flankers differ in some feature, that is irrelevant to the recognition task. In this study, the mechanisms of this effect were explored using targets and flankers of the same and different colours. It was found that facilitation nearly equal to that of differently coloured targets and flankers can be observed with a differently coloured background blob in the location of the target. The different-colour effect does not require advance knowledge of the target and flanker colours, but the effect increases in the course of three trials with constant mapping of colours. The results are consistent with the notion of exogenous attention that facilitates the processing at the most salient locations in the visual field. PMID:16718511

  4. Cueing vocabulary during sleep increases theta activity during later recognition testing.

    PubMed

    Schreiner, Thomas; Göldi, Maurice; Rasch, Björn

    2015-11-01

    Neural oscillations in the theta band have repeatedly been implicated in successful memory encoding and retrieval. Several recent studies have shown that memory retrieval can be facilitated by reactivating memories during their consolidation during sleep. However, it is still unknown whether reactivation during sleep also enhances subsequent retrieval-related neural oscillations. We have recently demonstrated that foreign vocabulary cues presented during sleep improve later recall of the associated translations. Here, we examined the effect of cueing foreign vocabulary during sleep on oscillatory activity during subsequent recognition testing after sleep. We show that those words that were replayed during sleep after learning (cued words) elicited stronger centroparietal theta activity during recognition as compared to noncued words. The reactivation-induced increase in theta oscillations during later recognition testing might reflect a strengthening of individual memory traces and the integration of the newly learned words into the mental lexicon by cueing during sleep.

  5. The effect of gaze direction on three-dimensional face recognition in infants.

    PubMed

    Yamashita, Wakayo; Kanazawa, So; Yamaguchi, Masami K

    2012-09-01

    Eye gaze is an important tool for social contact. In this study, we investigated whether direct gaze facilitates the recognition of three-dimensional face images in infants. We presented artificially produced face images in rotation to 6-8 month-old infants. The eye gaze of the face images was either direct or averted. Sixty-one sequential images of each face were created by rotating the vertical axis of the face from frontal view to ± 30°. The recognition performances of the infants were then compared between faces with direct gaze and faces with averted gaze. Infants showed evidence that they were able to discriminate the novel from familiarized face by 8 months of age and only when gaze is direct. These results suggest that gaze direction may affect three-dimensional face recognition in infants.

  6. Recognition Memory is Improved by a Structured Temporal Framework During Encoding

    PubMed Central

    Thavabalasingam, Sathesan; O’Neil, Edward B.; Zeng, Zheng; Lee, Andy C. H.

    2016-01-01

    In order to function optimally within our environment, we continuously extract temporal patterns from our experiences and formulate expectations that facilitate adaptive behavior. Given that our memories are embedded within spatiotemporal contexts, an intriguing possibility is that mnemonic processes are sensitive to the temporal structure of events. To test this hypothesis, in a series of behavioral experiments we manipulated the regularity of interval durations at encoding to create temporally structured and unstructured frameworks. Our findings revealed enhanced recognition memory (d′) for stimuli that were explicitly encoded within a temporally structured vs. unstructured framework. Encoding information within a temporally structured framework was also associated with a reduction in the negative effects of proactive interference and was linked to greater recollective recognition memory. Furthermore, rhythmic temporal structure was found to enhance recognition memory for incidentally encoded information. Collectively, these results support the possibility that we possess a greater capacity to learn and subsequently remember temporally structured information. PMID:26834673

  7. Recognition Memory is Improved by a Structured Temporal Framework During Encoding.

    PubMed

    Thavabalasingam, Sathesan; O'Neil, Edward B; Zeng, Zheng; Lee, Andy C H

    2015-01-01

    In order to function optimally within our environment, we continuously extract temporal patterns from our experiences and formulate expectations that facilitate adaptive behavior. Given that our memories are embedded within spatiotemporal contexts, an intriguing possibility is that mnemonic processes are sensitive to the temporal structure of events. To test this hypothesis, in a series of behavioral experiments we manipulated the regularity of interval durations at encoding to create temporally structured and unstructured frameworks. Our findings revealed enhanced recognition memory (d') for stimuli that were explicitly encoded within a temporally structured vs. unstructured framework. Encoding information within a temporally structured framework was also associated with a reduction in the negative effects of proactive interference and was linked to greater recollective recognition memory. Furthermore, rhythmic temporal structure was found to enhance recognition memory for incidentally encoded information. Collectively, these results support the possibility that we possess a greater capacity to learn and subsequently remember temporally structured information. PMID:26834673

  8. Handwritten digits recognition based on immune network

    NASA Astrophysics Data System (ADS)

    Li, Yangyang; Wu, Yunhui; Jiao, Lc; Wu, Jianshe

    2011-11-01

    With the development of society, handwritten digits recognition technique has been widely applied to production and daily life. It is a very difficult task to solve these problems in the field of pattern recognition. In this paper, a new method is presented for handwritten digit recognition. The digit samples firstly are processed and features extraction. Based on these features, a novel immune network classification algorithm is designed and implemented to the handwritten digits recognition. The proposed algorithm is developed by Jerne's immune network model for feature selection and KNN method for classification. Its characteristic is the novel network with parallel commutating and learning. The performance of the proposed method is experimented to the handwritten number datasets MNIST and compared with some other recognition algorithms-KNN, ANN and SVM algorithm. The result shows that the novel classification algorithm based on immune network gives promising performance and stable behavior for handwritten digits recognition.

  9. Studies of human vision recognition: some improvements

    NASA Astrophysics Data System (ADS)

    Wu, Bo-Wen; Fang, Yi-Chin; Chang, Lin-Song

    2010-01-01

    This paper proposes a new method to improve human recognition by artificial intelligence, specifically of images without the interference of high frequencies. The human eye is the most delicate optical system. Notwithstanding the dramatic progression of its structure and functions through a long evolution, the capability of visual recognition is not yet close to perfection. This paper is a study, based on the limitations of recognition by the human eye, of image recognition through the application of artificial intelligence. Those aspects which have been explored focus on human eye modeling, including aberration analysis, creative models of the human eye, human vision recognition characteristics and various mathematical models for verification. By using images consisting of four black and white bands and modulation transfer function (MTF) curve evaluation recognition capability on all the studied models, the optimum model most compatible with the physiology of the human eye is found.

  10. Speech recognition with amplitude and frequency modulations

    NASA Astrophysics Data System (ADS)

    Zeng, Fan-Gang; Nie, Kaibao; Stickney, Ginger S.; Kong, Ying-Yee; Vongphoe, Michael; Bhargave, Ashish; Wei, Chaogang; Cao, Keli

    2005-02-01

    Amplitude modulation (AM) and frequency modulation (FM) are commonly used in communication, but their relative contributions to speech recognition have not been fully explored. To bridge this gap, we derived slowly varying AM and FM from speech sounds and conducted listening tests using stimuli with different modulations in normal-hearing and cochlear-implant subjects. We found that although AM from a limited number of spectral bands may be sufficient for speech recognition in quiet, FM significantly enhances speech recognition in noise, as well as speaker and tone recognition. Additional speech reception threshold measures revealed that FM is particularly critical for speech recognition with a competing voice and is independent of spectral resolution and similarity. These results suggest that AM and FM provide independent yet complementary contributions to support robust speech recognition under realistic listening situations. Encoding FM may improve auditory scene analysis, cochlear-implant, and audiocoding performance. auditory analysis | cochlear implant | neural code | phase | scene analysis

  11. Document recognition serving people with disabilities

    NASA Astrophysics Data System (ADS)

    Fruchterman, James R.

    2007-01-01

    Document recognition advances have improved the lives of people with print disabilities, by providing accessible documents. This invited paper provides perspectives on the author's career progression from document recognition professional to social entrepreneur applying this technology to help people with disabilities. Starting with initial thoughts about optical character recognition in college, it continues with the creation of accurate omnifont character recognition that did not require training. It was difficult to make a reading machine for the blind in a commercial setting, which led to the creation of a nonprofit social enterprise to deliver these devices around the world. This network of people with disabilities scanning books drove the creation of Bookshare.org, an online library of scanned books. Looking forward, the needs for improved document recognition technology to further lower the barriers to reading are discussed. Document recognition professionals should be proud of the positive impact their work has had on some of society's most disadvantaged communities.

  12. Encoding and reinstatement of threat: recognition potentials.

    PubMed

    Weymar, Mathias; Bradley, Margaret M; Hamm, Alfons O; Lang, Peter J

    2014-01-01

    On a recognition test, stimuli originally encoded in the context of shock threat show an enhanced late parietal positivity during later recognition compared to stimuli encoded during safety, particularly for emotionally arousing stimuli. The present study investigated whether this ERP old/new effect is further influenced when a threat context is reinstated during the recognition test. ERPs were measured in a yes-no recognition test for words rated high or low in emotional arousal that were encoded and recognized in the context of cues that signaled threat of shock or safety. Correct recognition of words encoded under threat, irrespective of reinstatement, was associated with an enhanced old-new ERP difference (500-700ms; centro-parietal), and this difference was only reliable for emotionally arousing words. Taken together, the data suggest that information processed in a stressful context are associated with better recollection on later recognition, an effect that was not modulated by reinstating the stressful context at retrieval.

  13. Familiar people recognition disorders: an introductory review.

    PubMed

    Gainotti, Guido

    2014-01-01

    The aim of this introduction is to provide a general background for the individual contributions dealing with different aspects of familiar people recognition disorders. Following are the main points considered in this survey: 1) the cognitive models proposed to explain the functional architecture of processes subsuming familiar people recognition; 2) the different roles of the right and left hemisphere in identifying people by face voice and name; 3) the anatomical structures and the cognitive processes involved in face and voice recognition; 4) the interactions that exist among the perceptual processes subsuming face and voice recognition, but not people's faces, voices and proper names; 5) the patterns of multimodal defects of familiar people recognition and their implications for current cognitive models. Finally, there is a short discussion of two models advanced to explain the role of the anterior temporal lobes in people recognition.

  14. Automated leukocyte recognition using fuzzy divergence.

    PubMed

    Ghosh, Madhumala; Das, Devkumar; Chakraborty, Chandan; Ray, Ajoy K

    2010-10-01

    This paper aims at introducing an automated approach to leukocyte recognition using fuzzy divergence and modified thresholding techniques. The recognition is done through the segmentation of nuclei where Gamma, Gaussian and Cauchy type of fuzzy membership functions are studied for the image pixels. It is in fact found that Cauchy leads better segmentation as compared to others. In addition, image thresholding is modified for better recognition. Results are studied and discussed.

  15. The Resourceful Facilitator: Teacher Leaders Constructing Identities as Facilitators of Teacher Peer Groups

    ERIC Educational Resources Information Center

    Allen, David

    2016-01-01

    The use of teacher peer groups is a prevalent strategy for school-based professional development and instructional improvement. Facilitation of such groups is an increasingly vital dimension of teacher leadership as a component of school improvement efforts. Drawing on a qualitative study of facilitation of teacher peer groups, the article…

  16. From anxiety to enthusiasm: facilitating graduate nursing students' knowledge development in science and theory.

    PubMed

    McMillan, Diana E; Bell, Sandy; Benson, Ember E; Mandzuk, Lynda L; Matias, Debra M; McIvor, Marilyn J; Robertson, Judy E; Wilkins, Krista L

    2007-02-01

    Knowledge development of theory can be challenging for graduate nursing students when they experience deficits related to theoretical foundations, evaluation, or application. This article recounts the experiences of the students and course facilitator with a graduate-level nursing science and theory course, which required critical analysis of a concept, theory critique, and poster presentation. The idea for this article was generated when the students realized the profound importance of nursing theories and their applicability to practice and research. Students' anxiety gave way to enthusiasm with the implementation of teaching and learning strategies based on adult learning theory. Knowles' four characteristics of adult learners are discussed in relation to the experiences of the students and course facilitator. These characteristics include learners' wish to be self-directed, need to bring life experiences to their learning, recognition of their social and occupational role competencies, and need to take a more immediate, problem-solving approach to their learning.

  17. International Collaborative Learning--The Facilitation Process.

    ERIC Educational Resources Information Center

    Clear, A. G.

    International collaborative learning is becoming more viable through a variety of Internet enabled software products. Group Support Systems appear to offer promise. But it is not well understood how to facilitate the teaching and learning process in electronic environments. If education is to involve an interactive process of collaborative inquiry…

  18. Grief Support Group Curriculum: Facilitator's Handbook.

    ERIC Educational Resources Information Center

    Lehmann, Linda; Jimerson, Shane R.; Gaasch, Ann

    This handbook is designed for facilitators of grief support groups for mourning children. The first chapter discusses the history, philosophy, and format of a specific curriculum - the Mourning Child curriculum. This curriculum, originally written in 1986 and later expanded and revised, has been used with hundreds of children. Chapter two covers…

  19. Facilitating Learning Spaces in Forum Theatre

    ERIC Educational Resources Information Center

    Rae, Jan

    2013-01-01

    Purpose: The purpose of this paper is to evaluate the extent to which forum theatre interventions can support non-hierarchical approaches to learning, development and change management initiatives in organisations. Design/methodology/approach: Semi-structured interviews were carried out with theatre consultancies, actors/facilitators,…

  20. Retrieval during Learning Facilitates Subsequent Memory Encoding

    ERIC Educational Resources Information Center

    Pastotter, Bernhard; Schicker, Sabine; Niedernhuber, Julia; Bauml, Karl-Heinz T.

    2011-01-01

    In multiple-list learning, retrieval during learning has been suggested to improve recall of the single lists by enhancing list discrimination and, at test, reducing interference. Using electrophysiological, oscillatory measures of brain activity, we examined to what extent retrieval during learning facilitates list encoding. Subjects studied 5…

  1. Facilitating Engagement by Differentiating Independent Reading

    ERIC Educational Resources Information Center

    Kelley, Michelle J.; Clausen-Grace, Nicki

    2009-01-01

    The authors provide teachers with a rationale for engaging students in independent reading using a differentiated approach. By profiling types of readers, sharing observational tools, and offering teaching suggestions for each type of reader the authors give practical suggestions to facilitate reading engagement and make independent reading more…

  2. The Community Leisure Facilitator. Project REC.

    ERIC Educational Resources Information Center

    Moon, M. Sherril; And Others

    Developed as part of a project to integrate youth with disabilities into regular recreational and leisure activities, this report focuses on the role of the community leisure facilitator (CLF), defined as a professional, friend, family member, or volunteer who assists individuals with disabilities to enjoy the same leisure pursuits as other…

  3. Facilitated IEP Meetings. PHP-c90

    ERIC Educational Resources Information Center

    PACER Center, 2004

    2004-01-01

    To help special education planning teams reach agreements, the Minnesota Department of Education and the Minnesota Special Education Mediation Service (MNSEMS) provide the option of facilitated IEP meetings. This option is available for IEP (Individualized Education Program), IIIP (Individual Interagency Intervention Plan), and IFSP (Individual…

  4. 31 CFR 538.206 - Prohibited facilitation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Prohibited facilitation. 538.206 Section 538.206 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY SUDANESE SANCTIONS REGULATIONS...

  5. Facilitating Sustainable Professional Development through Lesson Study

    ERIC Educational Resources Information Center

    Hunter, Jodie; Back, Jenni

    2011-01-01

    Developing sustainable professional development which facilitates teachers of mathematics to develop effective mathematics pedagogy has been a key aim in recent years. This paper examines how lesson study can be used with networks of teachers as a vehicle to promote and sustain professional development. Drawing on findings from a year-long study…

  6. Does Teaching Creationism Facilitate Student Autonomy?

    ERIC Educational Resources Information Center

    Warnick, Bryan R.; Fooce, C. David

    2007-01-01

    The teaching of evolution in US public schools continues to generate controversy. One argument for including creationism in science classrooms is based on the goal of facilitating student autonomy. Autonomy requires that students be exposed to significant alternatives, it is argued, and religious creation stories offer a significant alternative to…

  7. Facilitating Transfer through Student Support Services.

    ERIC Educational Resources Information Center

    Brawer, Florence B.

    Drawing on findings of two Center for the Study of Community College (CSCC) projects, this paper reviews some of the services offered by community colleges to facilitate transfer to four-year institutions. Introductory material provides background on the low rates of student transfer and on the CSCC projects, which involve 6 large urban community…

  8. 31 CFR 537.205 - Prohibited facilitation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Prohibited facilitation. 537.205 Section 537.205 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY BURMESE SANCTIONS REGULATIONS...

  9. Perceived Benefits of Human Sexuality Peer Facilitators

    ERIC Educational Resources Information Center

    Butler, Scott M.; Hartzell, Rose M.; Sherwood, Catherine M.

    2008-01-01

    Peer education, facilitation, and counseling programs are commonly utilized in primary and secondary prevention programs within colleges and universities. In addition, peer-based human sexuality discussions have been used as an adjunct to traditional human sexuality pedagogic programs over the last 20 years. Whereas ample evidence suggests that…

  10. Supervisor Behaviours that Facilitate Training Transfer

    ERIC Educational Resources Information Center

    Lancaster, Sue; Di Milia, Lee; Cameron, Roslyn

    2013-01-01

    Purpose: The purpose of this paper is to describe the supervisor behaviours that employees found to be helpful and unhelpful in facilitating training transfer. The study aims to provide rich qualitative data from the employee's perspective. Design/methodology/approach: This study utilises a cross-sectional design. A case study and a qualitative…

  11. Utilizing the Internet to Facilitate Classroom Learning

    ERIC Educational Resources Information Center

    Tucker, Jan; Courts, Bari

    2010-01-01

    Traditional theories on classroom learning focus on fixed curriculum, static learning tools and believe learning is achieved through repetition and rote memorization. The instructor's role in a traditional learning environment focuses on providing direction to the student versus facilitating learning. As the technology age becomes more prevalent…

  12. How Academic Teachers Perceive and Facilitate Creativity

    ERIC Educational Resources Information Center

    Bjørner, Thomas; Kofoed, Lise Busk

    2013-01-01

    We will present a case study result from a cross-disciplinary education called Medialogy, which is taught in the Technical and Science Faculty at Aalborg University. The aim of Medialogy is to facilitate creativity within technical solutions. The intention of this paper is to answer the following: how do the Medialogy teachers perceive creativity…

  13. Videoconferencing: A New Opportunity to Facilitate Learning

    ERIC Educational Resources Information Center

    Mader, Cheryl; Ming, Kavin

    2015-01-01

    The use of distance learning techniques as a means of delivering instruction in higher education classrooms has become increasingly popular with the growing diversity of today's college students. Videoconferencing has been used as a tool to facilitate the simultaneous communication of individuals across varying geographic regions through the use…

  14. Facilitating Team Learning through Transformational Leadership

    ERIC Educational Resources Information Center

    Raes, Elisabeth; Decuyper, Stefan; Lismont, Bart; Van den Bossche, Piet; Kyndt, Eva; Demeyere, Sybille; Dochy, Filip

    2013-01-01

    This article investigates when and how teams engage in team learning behaviours (TLB). More specifically, it looks into how different leadership styles facilitate TLB by influencing the social conditions that proceed them. 498 healthcare workers from 28 nursery teams filled out a questionnaire measuring the concepts leadership style, TLB, social…

  15. Guide to Resources for ESL Literacy Facilitators.

    ERIC Educational Resources Information Center

    Gaber-Katz, Elaine; Zettel, Kathryn

    This resource guide, for English-as-a-Second-Language (ESL) literacy facilitators, reviews a variety of resources for ESL literacy. The guide contains three sections. The first section cites four books that provide a theoretical context for literacy work: "Ah-Hah! A New Approach to Popular Education" (Gatt-Fly); "Approaches and Methods in Language…

  16. Social Facilitation of Laughter in Children

    ERIC Educational Resources Information Center

    Chapman, Antony J.

    1973-01-01

    The present study is concerned primarily with demonstrating that laughter can be socially facilitated. It showed that children, presented aurally with laughter-provoking material, laugh more in the presence of a companion, whether or not the companion can hear the material. (Author/RK)

  17. Facilitating Learning Organizations. Making Learning Count.

    ERIC Educational Resources Information Center

    Marsick, Victoria J.; Watkins, Karen E.

    This book offers advice to facilitators and change agents who wish to build systems-level learning to create knowledge that can be used to gain a competitive advantage. Chapter 1 describes forces driving companies to build, sustain, and effectively use systems-level learning and presents and links a working definition of the learning organization…

  18. Facilitating Teaching and Learning across STEM Fields

    ERIC Educational Resources Information Center

    Ejiwale, James A.

    2012-01-01

    The reformation of the contents for instruction across STEM fields has changed the role of STEM educators from being a "dictator" in the classroom/laboratory to a facilitator of students' activities. More important, this new paradigm and professional orientation for STEM educators is no more limited to delivering instruction intuitively, but with…

  19. How Facilities Facilitate Education. Principal's Notebook.

    ERIC Educational Resources Information Center

    Quinn, Linda

    2001-01-01

    Advice on making facilities facilitate education includes: an educational vision comes first, involve all stakeholders, working smarter requires a systems approach, systems-focused planning takes time, partnerships stretch limited resources, "beautiful" is not expensive, change is tough, building a community is as important as building a facility,…

  20. Generic Language Facilitates Children's Cross-Classification

    ERIC Educational Resources Information Center

    Nguyen, Simone P.; Gelman, A.

    2012-01-01

    Four studies examined the role of generic language in facilitating 4- and 5-year-old children's ability to cross-classify. Participants were asked to classify an item into a familiar (taxonomic or script) category, then cross-classify it into a novel (script or taxonomic) category with the help of a clue expressed in either generic or specific…

  1. Body Posture Facilitates Retrieval of Autobiographical Memories

    ERIC Educational Resources Information Center

    Dijkstra, Katinka; Kaschak, Michael P.; Zwaan, Rolf A.

    2007-01-01

    We assessed potential facilitation of congruent body posture on access to and retention of autobiographical memories in younger and older adults. Response times were shorter when body positions during prompted retrieval of autobiographical events were similar to the body positions in the original events than when body position was incongruent.…

  2. Career Planning for Minority Women. Facilitator's Manual.

    ERIC Educational Resources Information Center

    Jackson, Stanlie M., Ed.

    This facilitator's manual consists of guidelines and materials for use in conducting a workshop dealing with career planning for minority women. Covered in the first half of the manual are the following aspects of implementing the workshop: background on the need for and development of the workshop, a workshop outline and time schedule, the…

  3. Management Basics for Minority Women. Facilitator's Manual.

    ERIC Educational Resources Information Center

    Jackson, Stanlie M., Ed.

    This facilitator's manual consists of guidelines and materials for use in conducting a workshop dealing with three management basics for minority women--communication, decision making, and interpersonal skills. Covered in the first half of the manual are the following aspects of implementing the workshop: background on the need for and development…

  4. Dynamic Flexibility and Proprioceptive Neuromuscular Facilitation.

    ERIC Educational Resources Information Center

    Hardy, Lew; Jones, David

    1986-01-01

    Two experiments are described which investigated whether results obtained in studies of static flexibility tranfer to dynamic flexibility. In both experiments, subjects were assigned to a group receiving proprioceptive neuromuscular facilitation training, ballistic stretching technique training or a control group. Results are presented and…

  5. Microcomputers as Social Facilitators in Integrated Preschools.

    ERIC Educational Resources Information Center

    Spiegel-McGill, Phyllis; And Others

    1989-01-01

    The study compared the effects of different play conditions (microcomputer, remote-control robot, or no toys) on the amount of time four dyads of handicapped/nonhandicapped children would interact during structured play. Results suggested that microcomputers may serve as social facilitators for children with significant social and language…

  6. Social Facilitation as Self-Presentation.

    ERIC Educational Resources Information Center

    Bond, Charles F., Jr.

    Social facilitation as a self-presentational display, and social performance impairment attributable to perceived public failure, are examined in a study of context effects in verbal learning. Female undergraduates (N=72) served as subjects with one male who served as an "audience." Performance data indicate that, consistent with the present…

  7. Facilitating Second Language Learning with Music

    ERIC Educational Resources Information Center

    Bae, Su-Young

    2006-01-01

    The use of music in facilitating second language (as well as first language) learning is supported by evidence that points to the musical nature of even preverbal infants. Music and language have been found to develop similarly, and researchers have noted advantages to using song in learning. The author observed her Korean 21-month-old for …

  8. The Facilitator. Technical Note No. 11.

    ERIC Educational Resources Information Center

    Barriga, Patricio; And Others

    This paper describes the concept, training, and experiences of community facilitators as change agents in a nonformal education project in rural Ecuador. Presently, the social, economic, and political context of the rural Ecuadorian consists of poverty, racial prejudice, economic exploitation, and psychological dependency. The project attempted to…

  9. Building Better Career Futures: Facilitator Guide.

    ERIC Educational Resources Information Center

    Bezanson, Lynne; Hopkins, Sareena

    This guide, designed to be used by facilitators of the Building Better Career Futures, a comprehensive career development program for young adults, is to be used in conjunction with the Backgrounder and the Portfolio Builder. It includes an introduction to the full program and lesson plans for all topics. Each lesson plan begins with a cover sheet…

  10. Facilitation and Practice in Verb Acquisition

    ERIC Educational Resources Information Center

    Keren-Portnoy, Tamar

    2006-01-01

    This paper presents a model of syntax acquisition, whose main points are as follows: Syntax is acquired in an item-based manner; early learning facilitates subsequent learning--as evidenced by the accelerating rate of new verbs entering a given structure; and mastery of syntactic knowledge is typically achieved through practice--as evidenced by…

  11. Facilitating Reminiscence Groups: Perceptions of Group Leaders

    ERIC Educational Resources Information Center

    Christensen, Teresa M.; Hulse-Killacky, Diana; Salgado, Roy A.; Thornton, Mark D.; Miller, Jason L.

    2006-01-01

    This article presents the results of a two-year qualitative investigation in which group leaders provided their perceptions of the process of facilitating reminiscence groups with elderly persons in a residential care facility. Group Culture emerged as the dominant construct. Findings from this study can serve guide leaders who are interested in…

  12. An overview of pattern recognition in the central arms of the PHENIX detector

    SciTech Connect

    Mitchell, J.T.

    1997-02-17

    It is predicted that a Au+Au event in the PHENIX Detector at RHIC will produce up to 800 charged particles in the PHENIX central arms. Pattern recognition algorithms are being developed to handle this hostile tracking environment. To facilitate the development of these algorithms, a suite of evaluators and event displays have been developed to calculate efficiencies and identify weaknesses in the algorithms. An overview of these algorithms and procedures will be discussed.

  13. Ordinal measures for iris recognition.

    PubMed

    Sun, Zhenan; Tan, Tieniu

    2009-12-01

    Images of a human iris contain rich texture information useful for identity authentication. A key and still open issue in iris recognition is how best to represent such textural information using a compact set of features (iris features). In this paper, we propose using ordinal measures for iris feature representation with the objective of characterizing qualitative relationships between iris regions rather than precise measurements of iris image structures. Such a representation may lose some image-specific information, but it achieves a good trade-off between distinctiveness and robustness. We show that ordinal measures are intrinsic features of iris patterns and largely invariant to illumination changes. Moreover, compactness and low computational complexity of ordinal measures enable highly efficient iris recognition. Ordinal measures are a general concept useful for image analysis and many variants can be derived for ordinal feature extraction. In this paper, we develop multilobe differential filters to compute ordinal measures with flexible intralobe and interlobe parameters such as location, scale, orientation, and distance. Experimental results on three public iris image databases demonstrate the effectiveness of the proposed ordinal feature models. PMID:19834142

  14. Sonority contours in word recognition

    NASA Astrophysics Data System (ADS)

    McLennan, Sean

    2003-04-01

    Contrary to the Generativist distinction between competence and performance which asserts that speech or perception errors are due to random, nonlinguistic factors, it seems likely that errors are principled and possibly governed by some of the same constraints as language. A preliminary investigation of errors modeled after the child's ``Chain Whisper'' game (a degraded stimulus task) suggests that a significant number of recognition errors can be characterized as an improvement in syllable sonority contour towards the linguistically least-marked, voiceless-stop-plus-vowel syllable. An independent study of sonority contours showed that approximately half of the English lexicon can be uniquely identified by their contour alone. Additionally, ``sororities'' (groups of words that share a single sonority contour), surprisingly, show no correlation to familiarity or frequency in either size or membership. Together these results imply that sonority contours may be an important factor in word recognition and in defining word ``neighborhoods.'' Moreover, they suggest that linguistic markedness constraints may be more prevalent in performance-related phenomena than previously accepted.

  15. Longitudinal study of fingerprint recognition

    PubMed Central

    Yoon, Soweon; Jain, Anil K.

    2015-01-01

    Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject’s age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis. PMID:26124106

  16. Innate Immune Recognition of EBV.

    PubMed

    Lünemann, Anna; Rowe, Martin; Nadal, David

    2015-01-01

    The ability of Epstein-Barr virus (EBV) to establish latency despite specific immune responses and to successfully persist lifelong in the human host shows that EBV has developed powerful strategies and mechanisms to exploit, evade, abolish, or downsize otherwise effective immune responses to ensure its own survival. This chapter focuses on current knowledge on innate immune responses against EBV and its evasion strategies for own benefit and summarizes the questions that remain to be tackled. Innate immune reactions against EBV originate both from the main target cells of EBV and from nontarget cells, which are elements of the innate immune system. Thus, we structured our review accordingly but with a particular focus on the innate recognition of EBV in its two stages in its life cycle, latent state and lytic replication. Specifically, we discuss (I) innate sensing and resulting innate immune responses against EBV by its main target cells, focusing on (i) EBV transmission between epithelial cells and B cells and their life cycle stages; and (ii) elements of innate immunity in EBV's target cells. Further, we debate (II) the innate recognition and resulting innate immune responses against EBV by cells other than the main target cells, focusing on (iii) myeloid cells: dendritic cells, monocytes, macrophages, and neutrophil granulocytes; and (iv) natural killer cells. Finally, we address (III) how EBV counteracts or exploits innate immunity in its latent and lytic life cycle stages, concentrating on (v) TLRs; (vi) EBERs; and (vii) microRNAs. PMID:26428378

  17. Dynamic chemistry of anion recognition

    SciTech Connect

    Custelcean, Radu

    2012-01-01

    In the past 40 years, anion recognition by synthetic receptors has grown into a rich and vibrant research topic, developing into a distinct branch of Supramolecular Chemistry. Traditional anion receptors comprise organic scaffolds functionalized with complementary binding groups that are assembled by multistep organic synthesis. Recently, a new approach to anion receptors has emerged, in which the host is dynamically self-assembled in the presence of the anionic guest, via reversible bond formation between functional building units. While coordination bonds were initially employed for the self-assembly of the anion hosts, more recent studies demonstrated that reversible covalent bonds can serve the same purpose. In both cases, due to their labile connections, the molecular constituents have the ability to assemble, dissociate, and recombine continuously, thereby creating a dynamic combinatorial library (DCL) of receptors. The anionic guests, through specific molecular recognition, may then amplify (express) the formation of a particular structure among all possible combinations (real or virtual) by shifting the equilibria involved towards the most optimal receptor. This approach is not limited to solution self-assembly, but is equally applicable to crystallization, where the fittest anion-binding crystal may be selected. Finally, the pros and cons of employing dynamic combinatorial chemistry (DCC) vs molecular design for developing anion receptors, and the implications of both approaches to selective anion separations, will be discussed.

  18. Longitudinal study of fingerprint recognition.

    PubMed

    Yoon, Soweon; Jain, Anil K

    2015-07-14

    Human identification by fingerprints is based on the fundamental premise that ridge patterns from distinct fingers are different (uniqueness) and a fingerprint pattern does not change over time (persistence). Although the uniqueness of fingerprints has been investigated by developing statistical models to estimate the probability of error in comparing two random samples of fingerprints, the persistence of fingerprints has remained a general belief based on only a few case studies. In this study, fingerprint match (similarity) scores are analyzed by multilevel statistical models with covariates such as time interval between two fingerprints in comparison, subject's age, and fingerprint image quality. Longitudinal fingerprint records of 15,597 subjects are sampled from an operational fingerprint database such that each individual has at least five 10-print records over a minimum time span of 5 y. In regard to the persistence of fingerprints, the longitudinal analysis on a single (right index) finger demonstrates that (i) genuine match scores tend to significantly decrease when time interval between two fingerprints in comparison increases, whereas the change in impostor match scores is negligible; and (ii) fingerprint recognition accuracy at operational settings, nevertheless, tends to be stable as the time interval increases up to 12 y, the maximum time span in the dataset. However, the uncertainty of temporal stability of fingerprint recognition accuracy becomes substantially large if either of the two fingerprints being compared is of poor quality. The conclusions drawn from 10-finger fusion analysis coincide with the conclusions from single-finger analysis.

  19. Toward the ultimate synthesis/recognition system.

    PubMed Central

    Furui, S

    1995-01-01

    This paper predicts speech synthesis, speech recognition, and speaker recognition technology for the year 2001, and it describes the most important research problems to be solved in order to arrive at these ultimate synthesis and recognition systems. The problems for speech synthesis include natural and intelligible voice production, prosody control based on meaning, capability of controlling synthesized voice quality and choosing individual speaking style, multilingual and multidialectal synthesis, choice of application-oriented speaking styles, capability of adding emotion, and synthesis from concepts. The problems for speech recognition include robust recognition against speech variations, adaptation/normalization to variations due to environmental conditions and speakers, automatic knowledge acquisition for acoustic and linguistic modeling, spontaneous speech recognition, naturalness and ease of human-machine interaction, and recognition of emotion. The problems for speaker recognition are similar to those for speech recognition. The research topics related to all these techniques include the use of articulatory and perceptual constraints and evaluation methods for measuring the quality of technology and systems. Images Fig. 3 PMID:7479723

  20. The picture superiority effect in a cross-modality recognition task.

    PubMed

    Stenbert, G; Radeborg, K; Hedman, L R

    1995-07-01

    Words and pictures were studied and recognition tests given in which each studied object was to be recognized in both word and picture format. The main dependent variable was the latency of the recognition decision. The purpose was to investigate the effects of study modality (word or picture), of congruence between study and test modalities, and of priming resulting from repeated testing. Experiments 1 and 2 used the same basic design, but the latter also varied retention interval. Experiment 3 added a manipulation of instructions to name studied objects, and Experiment 4 deviated from the others by presenting both picture and word referring to the same object together for study. The results showed that congruence between study and test modalities consistently facilitated recognition. Furthermore, items studied as pictures were more rapidly recognized than were items studied as words. With repeated testing, the second instance was affected by its predecessor, but the facilitating effect of picture-to-word priming exceeded that of word-to-picture priming. The finds suggest a two- stage recognition process, in which the first is based on perceptual familiarity and the second uses semantic links for a retrieval search. Common-code theories that grant privileged access to the semantic code for pictures or, alternatively, dual-code theories that assume mnemonic superiority for the image code are supported by the findings. Explanations of the picture superiority effect as resulting from dual encoding of pictures are not supported by the data. PMID:7666756

  1. Memory facilitation educed by food intake.

    PubMed

    Oomura, Y; Sasaki, K; Li, A J

    1993-09-01

    Acidic fibroblast growth factor (aFGF) in rat CSF increased 1000 times in the 2-h period after food intake, or IP, or ICV glucose infusion. The ICV application of aFGF dose dependently depresses and anti-aFGF antibody facilitates food intake. aFGF is produced in the ependymal cells and released into the CSF in response to increased glucose in the CSF caused by food intake. Released aFGF diffused into the brain parenchyma and was taken up into neurons in the hypothalamus, hippocampus, amygdala, etc. IP injection of glucose 2 h before a task that combined acquisition with passive avoidance significantly increased retention of avoidance by mice tested 24 h later. In a Morris water maze task, IP glucose injection 2 h before a first trial block reduced time to find and climb onto a platform hidden just below the water surface. The glucose facilitation of these affective and spatial memory were abolished by pretreatment with anti-aFGF antibody applied ICV. Continuous ICV infusion of aFGF into rats also significantly increased the reliability of passive avoidance for several days. After food intake, centrally released aFGF reaches the hippocampus and facilitates memory; peripherally released cholecystokinin reaches the endings of the afferent vagal nerves in the portal vein and changes their activity, which modulates hippocampal activity, to lead to memory facilitation. This, however, is blocked by vagotomy below the diaphragm. The results indicate the importance of food intake, not only to maintain homeostasis, but also to prepare a readiness state for memory facilitation. PMID:7692459

  2. Three dimensional pattern recognition using feature-based indexing and rule-based search

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Kyu

    . This data base organization according to object features facilitates machine learning in the context of a knowledge-base driven recognition algorithm. Lastly, feature-based indexing permits the recognition of 3D objects based on a comparatively small number of stored views, further limiting the size of the feature database. Experiments with real images as well as synthetic images including occluded (partially visible) objects are presented. The experiments show almost perfect recognition with feature-based indexing, if the detected features in the test scene are viewed from the same angle as the view on which the model is based. The experiments also show that the knowledge base is a highly effective and efficient search tool recognition performance is improved without increasing the database size requirements. The experimental results indicate that feature-based indexing in combination with a knowledge-based system will be a useful methodology for automatic target recognition (ATR).

  3. Facial recognition at the CIA

    NASA Astrophysics Data System (ADS)

    Gragg, Susan

    1997-01-01

    Law enforcement agencies need to identify suspects as they travel around the world. Terrorists and others change all sorts of information about themselves but their faces remain the same. The first operational facial recognition system (face trace) was developed at the Central Intelligence Agency (CIA) in the late eighties. It combines image analysis technology with collateral information to create an 'electronic mug book.' Using some simple collateral information about a suspect (height, age and sex) and a photograph, the system gives users the ability to identify an unknown person with a reasonable probability. The system matches information extracted from the photographs with similar information extracted from a database of photographs of existing suspects. The technology was subsequently transferred to the Immigration and Naturalization Service (INS) for use by the Border Patrol.

  4. Opportunity recognition in complex environments

    SciTech Connect

    Pryor, L.

    1996-12-31

    An agent operating in an unpredictable world must be able to take advantage of opportunities but cannot afford to perform a detailed analysis of the effects of every nuance of the current situation on its goals if it is to respond in a timely manner. This paper describes a filtering mechanism that enables the effective recognition of opportunities. The mechanism is based on a characterization of the world in terms of reference features, features that are both cheap and functional and that appear to be prevalent in everyday life. Its use enables the plan execution system PARETO to recognize types of opportunities that other systems cannot. Reference features can also play a role in the detection of threats, and may be involved in the development of expertise.

  5. Place recognition using batlike sonar.

    PubMed

    Vanderelst, Dieter; Steckel, Jan; Boen, Andre; Peremans, Herbert; Holderied, Marc W

    2016-01-01

    Echolocating bats have excellent spatial memory and are able to navigate to salient locations using bio-sonar. Navigating and route-following require animals to recognize places. Currently, it is mostly unknown how bats recognize places using echolocation. In this paper, we propose template based place recognition might underlie sonar-based navigation in bats. Under this hypothesis, bats recognize places by remembering their echo signature - rather than their 3D layout. Using a large body of ensonification data collected in three different habitats, we test the viability of this hypothesis assessing two critical properties of the proposed echo signatures: (1) they can be uniquely classified and (2) they vary continuously across space. Based on the results presented, we conclude that the proposed echo signatures satisfy both criteria. We discuss how these two properties of the echo signatures can support navigation and building a cognitive map. PMID:27481189

  6. Plant pattern-recognition receptors.

    PubMed

    Zipfel, Cyril

    2014-07-01

    Plants are constantly exposed to would-be pathogens in their immediate environment. Yet, despite relying on innate immunity only, plants are resistant to most microbes. They employ pattern-recognition receptors (PRRs) for sensitive and rapid detection of the potential danger caused by microbes and pests. Plant PRRs are either surface-localized receptor kinases (RKs) or receptor-like proteins (RLPs) containing various ligand-binding ectodomains that perceive pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). In this review, I summarize our current knowledge of plant PRRs and their ligands, illustrating the multiple molecular strategies employed by plant PRRs to activate innate immune signaling to survive.

  7. Aircraft recognition and tracking device

    NASA Astrophysics Data System (ADS)

    Filis, Dimitrios P.; Renios, Christos I.

    2011-11-01

    The technology of aircraft recognition and tracking has various applications in all areas of air navigation, be they civil or military, spanning from air traffic control and regulation at civilian airports to anti-aircraft weapon handling and guidance for military purposes.1, 18 The system presented in this thesis is an alternative implementation of identifying and tracking flying objects, which benefits from the optical spectrum by using an optical camera built into a servo motor (pan-tilt unit). More specifically, through the purpose-developed software, when a target (aircraft) enters the field of view of the camera18, it is both detected and identified.5, 22 Then the servo motor, being provided with data on target position and velocity, tracks the aircraft while it is in constant communication with the camera (Fig. 1). All the features are so designed as to operate under real time conditions.

  8. Recognition of Handwriting from Electromyography

    PubMed Central

    Linderman, Michael; Lebedev, Mikhail A.; Erlichman, Joseph S.

    2009-01-01

    Handwriting – one of the most important developments in human culture – is also a methodological tool in several scientific disciplines, most importantly handwriting recognition methods, graphology and medical diagnostics. Previous studies have relied largely on the analyses of handwritten traces or kinematic analysis of handwriting; whereas electromyographic (EMG) signals associated with handwriting have received little attention. Here we show for the first time, a method in which EMG signals generated by hand and forearm muscles during handwriting activity are reliably translated into both algorithm-generated handwriting traces and font characters using decoding algorithms. Our results demonstrate the feasibility of recreating handwriting solely from EMG signals – the finding that can be utilized in computer peripherals and myoelectric prosthetic devices. Moreover, this approach may provide a rapid and sensitive method for diagnosing a variety of neurogenerative diseases before other symptoms become clear. PMID:19707562

  9. Task-oriented situation recognition

    NASA Astrophysics Data System (ADS)

    Bauer, Alexander; Fischer, Yvonne

    2010-04-01

    From the advances in computer vision methods for the detection, tracking and recognition of objects in video streams, new opportunities for video surveillance arise: In the future, automated video surveillance systems will be able to detect critical situations early enough to enable an operator to take preventive actions, instead of using video material merely for forensic investigations. However, problems such as limited computational resources, privacy regulations and a constant change in potential threads have to be addressed by a practical automated video surveillance system. In this paper, we show how these problems can be addressed using a task-oriented approach. The system architecture of the task-oriented video surveillance system NEST and an algorithm for the detection of abnormal behavior as part of the system are presented and illustrated for the surveillance of guests inside a video-monitored building.

  10. Place recognition using batlike sonar.

    PubMed

    Vanderelst, Dieter; Steckel, Jan; Boen, Andre; Peremans, Herbert; Holderied, Marc W

    2016-01-01

    Echolocating bats have excellent spatial memory and are able to navigate to salient locations using bio-sonar. Navigating and route-following require animals to recognize places. Currently, it is mostly unknown how bats recognize places using echolocation. In this paper, we propose template based place recognition might underlie sonar-based navigation in bats. Under this hypothesis, bats recognize places by remembering their echo signature - rather than their 3D layout. Using a large body of ensonification data collected in three different habitats, we test the viability of this hypothesis assessing two critical properties of the proposed echo signatures: (1) they can be uniquely classified and (2) they vary continuously across space. Based on the results presented, we conclude that the proposed echo signatures satisfy both criteria. We discuss how these two properties of the echo signatures can support navigation and building a cognitive map.

  11. Recognition of movement object collision

    NASA Astrophysics Data System (ADS)

    Chang, Hsiao Tsu; Sun, Geng-tian; Zhang, Yan

    1991-03-01

    The paper explores the collision recognition of two objects in both crisscross and revolution motions A mathematical model has been established based on the continuation theory. The objects of any shape may be regarded as being built of many 3siniplexes or their convex hulls. Therefore the collision problem of two object in motion can be reduced to the collision of two corresponding 3siinplexes on two respective objects accordingly. Thus an optimized algorithm is developed for collision avoidance which is suitable for computer control and eliminating the need for vision aid. With this algorithm computation time has been reduced significantly. This algorithm is applicable to the path planning of mobile robots And also is applicable to collision avoidance of the anthropomorphic arms grasping two complicated shaped objects. The algorithm is realized using LISP language on a VAX8350 minicomputer.

  12. Drug-facilitated sexual assault ('date rape').

    PubMed

    Schwartz, R H; Milteer, R; LeBeau, M A

    2000-06-01

    In the past few years, drug-facilitated sexual assaults have received widespread media coverage. In addition to alcohol, the most frequently used date-rape drug, flunitrazepam (Rohypnol), a fast-acting benzodiazepine, and gamma-hydroxybutyrate (GHB) and its congeners are among the most popular drugs used for this purpose. The latter drug is easily procured at some gymnasiums, popular bars, discos, and rave clubs, as well as over the Internet. Perpetrators choose these drugs because they act rapidly, produce disinhibition and relaxation of voluntary muscles, and cause the victim to have lasting anterograde amnesia for events that occur under the influence of the drug. Alcoholic beverages potentiate the drug effects. We review several date-rape drugs, provide information on laboratory testing for them, and offer guidelines for preventing drug-facilitated sexual assault. PMID:10881768

  13. Prior expectations facilitate metacognition for perceptual decision.

    PubMed

    Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

    2015-09-01

    The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition.

  14. How academic teachers perceive and facilitate creativity

    NASA Astrophysics Data System (ADS)

    Bjørner, Thomas; Busk Kofoed, Lise

    2013-10-01

    We will present a case study result from a cross-disciplinary education called Medialogy, which is taught in the Technical and Science Faculty at Aalborg University. The aim of Medialogy is to facilitate creativity within technical solutions. The intention of this paper is to answer the following: how do the Medialogy teachers perceive creativity and how do they facilitate it? Many of the answers point to the pedagogical approach used in problem-based learning, which are perceived as an important element for the creative process. In this paper we will also argue the importance of including the social context (both at a macro and at a micro level) in the definition and use of creativity in engineering education.

  15. Generic language facilitates children's cross-classification

    PubMed Central

    Nguyen, Simone P.; Gelman, Susan A.

    2012-01-01

    Four studies examined the role of generic language in facilitating 4- and 5-year-old children's ability to cross-classify. Participants were asked to classify an item into a familiar (taxonomic or script) category, then cross-classify it into a novel (script or taxonomic) category with the help of a clue expressed in either generic or specific language. Experiment 1 showed that generics facilitate 5-year-olds' and adults' cross-classification when expressed at an appropriate level of generalization (e.g., “foods,” “birthday party things”), whereas Experiment 2 showed that such effects disappeared when labels were at an inappropriate level of generalization (e.g., “pizzas,” “balloons”). Experiments 3 and 4 offered additional controls. Taken together, the findings demonstrate that language can guide and direct children's multiple categorizations. PMID:22888182

  16. Does supplementary reinforcement of stereotypy facilitate extinction?

    PubMed

    Dozier, Claudia L; Iwata, Brian A; Wilson, David M; Thomason-Sassi, Jessica L; Roscoe, Eileen M

    2013-01-01

    Results of several studies suggest that delivery of supplemental (social) reinforcement for stereotypy might facilitate its subsequent extinction. We examined this possibility with 9 subjects who engaged in stereotypy by including methodological refinements to ensure that (a) subjects' stereotypy was maintained in the absence of social consequences, (b) supplementary reinforcers were highly preferred and were shown to be reinforcers for some behavior, and (c) subjects were exposed to lengthy reinforcement and extinction conditions. In spite of these modifications, only 4 subjects' stereotypy increased when supplementary reinforcement was delivered contingent on stereotypy, and no subject's stereotypy decreased below initial baseline levels when social reinforcement was subsequently withheld. Decreases in stereotypy occurred with the implementation of noncontingent reinforcement. Thus, delivery of supplementary reinforcers either did not increase stereotypy or did not facilitate extinction of stereotypy maintained by automatic reinforcement. We discuss the practical and conceptual bases of these results with respect to our current understanding of function-based interventions.

  17. Facilitating emergent change in a healthcare setting.

    PubMed

    Dickens, Peter M

    2013-01-01

    During my doctoral research, I identified new ways of thinking about complexity in organizations. This involved embracing the capacity of complex systems to find their own form of order and coherence, often referred to as self-organization, and then asking the question, "What can organizational leaders do to create the systems and structures that would facilitate emergent change?" Emergent change comes from within and through the active members of a system and not according to some external prompting or design. This results in the sort of change capacity that enables an organization to be agile and resilient through a high level of employee engagement. The question was answered by identifying and validating organizational-specific factors that facilitate emergent change.

  18. Effects of glucose administration on category exclusion recognition.

    PubMed

    Brandt, Karen R

    2015-07-01

    Previous research has produced discrepant findings as to whether glucose administration effects lead to enhanced recollection or arise only under dual-task conditions. The aim of the present research was to address these issues by firstly employing an alternative cognitively demanding paradigm that has been linked to hippocampal function, i.e. the Process Dissociation Procedure (PDP). A second aim was to use this paradigm to explore whether glucose affects qualitative aspects of memory function. To achieve these aims, the PDP task was administered to participants who had either consumed a glucose (25 g) or aspartame-sweetened control drink. Results demonstrated glucose facilitation effects only under difficult task conditions and with no such effect emerging for the process of recollection. The present results support the contention that the beneficial effects of glucose arise under hippocampally driven, cognitively demanding task conditions, and that this effect enhances quantitative but not qualitative aspects of recognition memory. PMID:25693890

  19. Parasite calcineurin regulates host cell recognition and attachment by apicomplexans

    PubMed Central

    Paul, Aditya S.; Saha, Sudeshna; Engelberg, Klemens; Jiang, Rays H.Y.; Coleman, Bradley I.; Kosber, Aziz L.; Chen, Chun-Ti; Ganter, Markus; Espy, Nicole; Gilberger, Tim W.; Gubbels, Marc-Jan; Duraisingh, Manoj T.

    2015-01-01

    SUMMARY Apicomplexans invade a variety of metazoan host cells through mechanisms involving host cell receptor engagement and secretion of parasite factors to facilitate cellular attachment. We find that the parasite homolog of calcineurin, a calcium-regulated phosphatase complex central to signal transduction in eukaryotes, also contributes to host cell invasion by the malaria parasite Plasmodium falciparum and related Toxoplasma gondii. Using reverse genetic and chemical-genetic approaches, we determine that calcineurin critically regulates and stabilizes attachment of extracellular P. falciparum to host erythrocytes before intracellular entry and has similar functions in host cell engagement by T. gondii. Calcineurin-mediated Plasmodium invasion is strongly associated with host receptors required for host cell recognition and calcineurin function distinguishes this form of receptor-mediated attachment from a second mode of host-parasite adhesion independent of host receptors. This specific role of calcineurin in coordinating physical interactions with host cells highlights an ancestral mechanism for parasitism used by apicomplexans. PMID:26118996

  20. Recognition memory reveals just how CONTRASTIVE contrastive accenting really is

    PubMed Central

    Fraundorf, Scott H.; Watson, Duane G.; Benjamin, Aaron S.

    2010-01-01

    The effects of pitch accenting on memory were investigated in three experiments. Participants listened to short recorded discourses that contained contrast sets with two items (e.g. British scientists and French scientists); a continuation specified one item from the set. Pitch accenting on the critical word in the continuation was manipulated between non-contrastive (H* in the ToBI system) and contrastive (L+H*). On subsequent recognition memory tests, the L+H* accent increased hits to correct statements and correct rejections of the contrast item (Experiments 1–3), but did not impair memory for other parts of the discourse (Experiment 2). L+H* also did not facilitate correct rejections of lures not in the contrast set (Experiment 3), indicating that contrastive accents do not simply strengthen the representation of the target item. These results suggest comprehenders use pitch accenting to encode and update information about multiple elements in a contrast set. PMID:20835405

  1. The recognition of ubiquitinated proteins by the proteasome.

    PubMed

    Grice, Guinevere L; Nathan, James A

    2016-09-01

    The ability of ubiquitin to form up to eight different polyubiquitin chain linkages generates complexity within the ubiquitin proteasome system, and accounts for the diverse roles of ubiquitination within the cell. Understanding how each type of ubiquitin linkage is correctly interpreted by ubiquitin binding proteins provides important insights into the link between chain recognition and cellular fate. A major function of ubiquitination is to signal degradation of intracellular proteins by the 26S proteasome. Lysine-48 (K48) linked polyubiquitin chains are well established as the canonical signal for proteasomal degradation, but recent studies show a role for other ubiquitin linked chains in facilitating degradation by the 26S proteasome. Here, we review how different types of polyubiquitin linkage bind to ubiquitin receptors on the 26S proteasome, how they signal degradation and discuss the implications of ubiquitin chain linkage in regulating protein breakdown by the proteasome. PMID:27137187

  2. Effects of glucose administration on category exclusion recognition.

    PubMed

    Brandt, Karen R

    2015-07-01

    Previous research has produced discrepant findings as to whether glucose administration effects lead to enhanced recollection or arise only under dual-task conditions. The aim of the present research was to address these issues by firstly employing an alternative cognitively demanding paradigm that has been linked to hippocampal function, i.e. the Process Dissociation Procedure (PDP). A second aim was to use this paradigm to explore whether glucose affects qualitative aspects of memory function. To achieve these aims, the PDP task was administered to participants who had either consumed a glucose (25 g) or aspartame-sweetened control drink. Results demonstrated glucose facilitation effects only under difficult task conditions and with no such effect emerging for the process of recollection. The present results support the contention that the beneficial effects of glucose arise under hippocampally driven, cognitively demanding task conditions, and that this effect enhances quantitative but not qualitative aspects of recognition memory.

  3. Aromatic rings in chemical and biological recognition: energetics and structures.

    PubMed

    Salonen, Laura M; Ellermann, Manuel; Diederich, François

    2011-05-16

    This review describes a multidimensional treatment of molecular recognition phenomena involving aromatic rings in chemical and biological systems. It summarizes new results reported since the appearance of an earlier review in 2003 in host-guest chemistry, biological affinity assays and biostructural analysis, data base mining in the Cambridge Structural Database (CSD) and the Protein Data Bank (PDB), and advanced computational studies. Topics addressed are arene-arene, perfluoroarene-arene, S⋅⋅⋅aromatic, cation-π, and anion-π interactions, as well as hydrogen bonding to π systems. The generated knowledge benefits, in particular, structure-based hit-to-lead development and lead optimization both in the pharmaceutical and in the crop protection industry. It equally facilitates the development of new advanced materials and supramolecular systems, and should inspire further utilization of interactions with aromatic rings to control the stereochemical outcome of synthetic transformations. PMID:21538733

  4. Proline-rich Sequence Recognition

    PubMed Central

    Schlundt, Andreas; Sticht, Jana; Piotukh, Kirill; Kosslick, Daniela; Jahnke, Nadin; Keller, Sandro; Schuemann, Michael; Krause, Eberhard; Freund, Christian

    2009-01-01

    The tumor maintenance protein Tsg101 has recently gained much attention because of its involvement in endosomal sorting, virus release, cytokinesis, and cancerogenesis. The ubiquitin-E2-like variant (UEV) domain of the protein interacts with proline-rich sequences of target proteins that contain P(S/T)AP amino acid motifs and weakly binds to the ubiquitin moiety of proteins committed to sorting or degradation. Here we performed peptide spot analysis and phage display to refine the peptide binding specificity of the Tsg101 UEV domain. A mass spectrometric proteomics approach that combines domain-based pulldown experiments, binding site inactivation, and stable isotope labeling by amino acids in cell culture (SILAC) was then used to delineate the relative importance of the peptide and ubiquitin binding sites. Clearly “PTAP” interactions dominate target recognition, and we identified several novel binders as for example the poly(A)-binding protein 1 (PABP1), Sec24b, NFκB2, and eIF4b. For PABP1 and eIF4b the interactions were confirmed in the context of the corresponding full-length proteins in cellular lysates. Therefore, our results strongly suggest additional roles of Tsg101 in cellular regulation of mRNA translation. Regulation of Tsg101 itself by the ubiquitin ligase TAL (Tsg101-associated ligase) is most likely conferred by a single PSAP binding motif that enables the interaction with Tsg101 UEV. Together with the results from the accompanying article (Kofler, M., Schuemann, M., Merz, C., Kosslick, D., Schlundt, A., Tannert, A., Schaefer, M., Lührmann, R., Krause, E., and Freund, C. (2009) Proline-rich sequence recognition: I. Marking GYF and WW domain assembly sites in early spliceosomal complexes. Mol. Cell. Proteomics 8, 2461–2473) on GYF and WW domain pathways our work defines major proline-rich sequence-mediated interaction networks that contribute to the modular assembly of physiologically relevant protein complexes. PMID:19542561

  5. Neural mechanisms for voice recognition.

    PubMed

    Andics, Attila; McQueen, James M; Petersson, Karl Magnus; Gál, Viktor; Rudas, Gábor; Vidnyánszky, Zoltán

    2010-10-01

    We investigated neural mechanisms that support voice recognition in a training paradigm with fMRI. The same listeners were trained on different weeks to categorize the mid-regions of voice-morph continua as an individual's voice. Stimuli implicitly defined a voice-acoustics space, and training explicitly defined a voice-identity space. The pre-defined centre of the voice category was shifted from the acoustic centre each week in opposite directions, so the same stimuli had different training histories on different tests. Cortical sensitivity to voice similarity appeared over different time-scales and at different representational stages. First, there were short-term adaptation effects: increasing acoustic similarity to the directly preceding stimulus led to haemodynamic response reduction in the middle/posterior STS and in right ventrolateral prefrontal regions. Second, there were longer-term effects: response reduction was found in the orbital/insular cortex for stimuli that were most versus least similar to the acoustic mean of all preceding stimuli, and, in the anterior temporal pole, the deep posterior STS and the amygdala, for stimuli that were most versus least similar to the trained voice-identity category mean. These findings are interpreted as effects of neural sharpening of long-term stored typical acoustic and category-internal values. The analyses also reveal anatomically separable voice representations: one in a voice-acoustics space and one in a voice-identity space. Voice-identity representations flexibly followed the trained identity shift, and listeners with a greater identity effect were more accurate at recognizing familiar voices. Voice recognition is thus supported by neural voice spaces that are organized around flexible 'mean voice' representations. PMID:20553895

  6. Cortical dynamics of word recognition.

    PubMed

    Mainy, Nelly; Jung, Julien; Baciu, Monica; Kahane, Philippe; Schoendorff, Benjamin; Minotti, Lorella; Hoffmann, Dominique; Bertrand, Olivier; Lachaux, Jean-Philippe

    2008-11-01

    While functional neuroimaging studies have helped elucidate major regions implicated in word recognition, much less is known about the dynamics of the associated activations or the actual neural processes of their functional network. We used intracerebral electroencephalography recordings in 10 patients with epilepsy to directly measure neural activity in the temporal and frontal lobes during written words' recognition, predominantly in the left hemisphere. The patients were presented visually with consonant strings, pseudo-words, and words and performed a hierarchical paradigm contrasting semantic processes (living vs. nonliving word categorization task), phonological processes (rhyme decision task on pseudo-words), and visual processes (visual analysis of consonant strings). Stimuli triggered a cascade of modulations in the gamma-band (>40 Hz) with reproducible timing and task-sensitivity throughout the functional reading network: the earliest gamma-band activations were observed for all stimuli in the mesial basal temporal lobe at 150 ms, reaching the word form area in the mid fusiform gyrus at 200 ms, evidencing a superiority effect for word-like stimuli. Peaks of gamma-band activations were then observed for word-like stimuli after 400 ms in the anterior and middle portion of the superior temporal gyrus (BA 38 and BA 22 respectively), in the pars triangularis of Broca's area for the semantic task (BAs 45 and 47), and in the pars opercularis for the phonological task (BA 44). Concurrently, we observed a two-pronged effect in the prefrontal cortex (BAs 9 and 46), with nonspecific sustained dorsal activation related to sustained attention and, more ventrally, a strong reflex deactivation around 500 ms, possibly due to semantic working memory reset. PMID:17712785

  7. Dissociated Signals in Human Dentate Gyrus and CA3 Predict Different Facets of Recognition Memory

    PubMed Central

    Reagh, Zachariah M.; Watabe, Joseph; Ly, Maria; Murray, Elizabeth

    2014-01-01

    A wealth of evidence has implicated the hippocampus and surrounding medial temporal lobe cortices in support of recognition memory. However, the roles of the various subfields of the hippocampus are poorly understood. In this study, we concurrently varied stimulus familiarization and repetition to engage different facets of recognition memory. Using high-resolution fMRI (1.5 mm isotropic), we observed distinct familiarity and repetition-related recognition signal profiles in the dentate gyrus (DG)/CA3 subfield in human subjects. The DG/CA3 demonstrated robust response suppression with repetition and familiarity-related facilitation. Both of these discrete responses were predictive of different aspects of behavioral performance. Consistent with previous work, we observed novelty responses in CA1 consistent with “match/mismatch detection,” as well as mixed recognition signaling distributed across medial temporal lobe cortices. Additional analyses indicated that the repetition and familiarity-related signals in the DG/CA3 were strikingly dissociated along the hippocampal longitudinal axis and that activity in the posterior hippocampus was strongly correlated with the retrosplenial cortex. These data provide novel insight into the roles of hippocampal subfields in support of recognition memory and further provide evidence of a functional heterogeneity in the human DG/CA3, particularly along the longitudinal axis. PMID:25274810

  8. Statistical properties of infant-directed versus adult-directed speech: Insights from speech recognition

    NASA Astrophysics Data System (ADS)

    Kirchhoff, Katrin; Schimmel, Steven

    2005-04-01

    Previous studies have shown that infant-directed speech (`motherese') exhibits overemphasized acoustic properties which may facilitate the acquisition of phonetic categories by infant learners. It has been suggested that the use of infant-directed data for training automatic speech recognition systems might also enhance the automatic learning and discrimination of phonetic categories. This study investigates the properties of infant-directed vs. adult-directed speech from the point of view of the statistical pattern recognition paradigm underlying automatic speech recognition. Isolated-word speech recognizers were trained on adult-directed vs. infant-directed data sets and were tested on both matched and mismatched data. Results show that recognizers trained on infant-directed speech did not always exhibit better recognition performance; however, their relative loss in performance on mismatched data was significantly less severe than that of recognizers trained on adult-directed speech and presented with infant-directed test data. An analysis of the statistical distributions of a subset of phonetic classes in both data sets showed that this pattern is caused by larger class overlaps in infant-directed speech. This finding has implications for both automatic speech recognition and theories of infant speech perception. .

  9. Dissociated signals in human dentate gyrus and CA3 predict different facets of recognition memory.

    PubMed

    Reagh, Zachariah M; Watabe, Joseph; Ly, Maria; Murray, Elizabeth; Yassa, Michael A

    2014-10-01

    A wealth of evidence has implicated the hippocampus and surrounding medial temporal lobe cortices in support of recognition memory. However, the roles of the various subfields of the hippocampus are poorly understood. In this study, we concurrently varied stimulus familiarization and repetition to engage different facets of recognition memory. Using high-resolution fMRI (1.5 mm isotropic), we observed distinct familiarity and repetition-related recognition signal profiles in the dentate gyrus (DG)/CA3 subfield in human subjects. The DG/CA3 demonstrated robust response suppression with repetition and familiarity-related facilitation. Both of these discrete responses were predictive of different aspects of behavioral performance. Consistent with previous work, we observed novelty responses in CA1 consistent with "match/mismatch detection," as well as mixed recognition signaling distributed across medial temporal lobe cortices. Additional analyses indicated that the repetition and familiarity-related signals in the DG/CA3 were strikingly dissociated along the hippocampal longitudinal axis and that activity in the posterior hippocampus was strongly correlated with the retrosplenial cortex. These data provide novel insight into the roles of hippocampal subfields in support of recognition memory and further provide evidence of a functional heterogeneity in the human DG/CA3, particularly along the longitudinal axis.

  10. Writing reports to facilitate patent applications.

    SciTech Connect

    Libman, George H.; Doerry, Armin Walter

    2004-06-01

    Brief disclosures may often be sufficient for the filing of a Technical Advance with Sandia's Intellectual Property Center, but still be inadequate to facilitate an optimum patent application where more detail and explanation are required. Consequently, the crafting of a patent application may require considerably more additional interaction between the application preparer and the inventors. This inefficiency can be considerably mitigated if the inventors address some critical aspects of a patent application when they write a technical report.

  11. A facilitated mentoring process for engineers

    SciTech Connect

    Donald, L.; Clark, M.

    1993-11-01

    Mentoring has been occurring in organizations for many, many years through a natural pairing process of people wanting to help one another. The numerous benefits of mentoring to both the protege and the mentor are widely known. In this paper we describe a Facilitated Mentoring Pilot Program for engineers, successfully completed in June, 1993. This career development tool can help make ``Every Engineer a Leader.``

  12. Conditions under which lorazepam can facilitate retrieval.

    PubMed

    File, S E; Fluck, E; Joyce, E M

    1999-08-01

    Memory is composed of three stages: acquisition, consolidation, and retrieval. By impairing acquisition processes, benzodiazepines cause anterograde amnesia while leaving intact information learned before the drug was taken. In some circumstances, retrieval of this information is even improved by benzodiazepines. It has been hypothesized that this phenomenon is not a true facilitation of retrieval processes, but is the result of reduced interference from items presented after drug administration and is thus a secondary consequence of drug-induced amnesia. Experiment 1 investigated the effect of 0.5, 1, and 2.5 mg of lorazepam on explicit episodic memory in healthy young volunteers. The 1-mg dose was found to significantly improve recall of items presented before drug administration without causing amnesia for items presented after drug administration, thus excluding an interference explanation. Experiment 2 investigated the conditions necessary to obtain facilitated retrieval with 1 mg of lorazepam. The results showed that facilitation was found only when two lists of semantically related material were presented, but that both of the lists could be presented before drug administration, thus excluding an effect of lorazepam on consolidation. Facilitation could be demonstrated in both direct (free recall) and indirect (backwards reading) retrieval tasks and when all of the material was presented after lorazepam administration. This improved retrieval could therefore be of clinical relevance, but any benefits would be reduced at higher doses that at the same time impair acquisition of new information. However, because 1 mg of lorazepam is an effective anxiolytic dose, these results suggest that it is possible to combine effective anxiety reduction with some benefits to memory.

  13. The Commission on Magnet® Recognition.

    PubMed

    Moran, Janice W

    2016-09-01

    The American Nurses Credentialing Center (ANCC) Commission on Magnet® Recognition is a voluntary governing body that oversees the Magnet Recognition Program®. Commission members are appointed by the ANCC Board of Directors and are expert representatives from various sectors of the nursing community. In addition, 1 commission member represents public consumers. PMID:27556648

  14. Sign and Word Recognition: A First Comparison.

    ERIC Educational Resources Information Center

    Grosjean, Francois

    1981-01-01

    The results of a word recognition study are compared to those of a sign recognition study in order to determine which aspects of lexical access are comparable in speech and sign, and which are specific to each of the two language modalities. The "gating paradigm" was used in both studies. (Author/AMH)

  15. Adult Word Recognition and Visual Sequential Memory

    ERIC Educational Resources Information Center

    Holmes, V. M.

    2012-01-01

    Two experiments were conducted investigating the role of visual sequential memory skill in the word recognition efficiency of undergraduate university students. Word recognition was assessed in a lexical decision task using regularly and strangely spelt words, and nonwords that were either standard orthographically legal strings or items made from…

  16. Performing speech recognition research with hypercard

    NASA Technical Reports Server (NTRS)

    Shepherd, Chip

    1993-01-01

    The purpose of this paper is to describe a HyperCard-based system for performing speech recognition research and to instruct Human Factors professionals on how to use the system to obtain detailed data about the user interface of a prototype speech recognition application.

  17. Voice Recognition: A New Assessment Tool?

    ERIC Educational Resources Information Center

    Jones, Darla

    2005-01-01

    This article presents the results of a study conducted in Anchorage, Alaska, that evaluated the accuracy and efficiency of using voice recognition (VR) technology to collect oral reading fluency data for classroom-based assessments. The primary research question was as follows: Is voice recognition technology a valid and reliable alternative to…

  18. The Status of Voice Recognition Technology.

    ERIC Educational Resources Information Center

    Miller, Ruth

    1986-01-01

    After examining the historical view of voice recognition, voice recognition technology today, the future of this technology, and information processing applications, the author states that educators must begin to prepare for tomorrow's technology now by researching current literature, analyzing hardware and software needs, and emphasizing oral…

  19. Short-Term Recognition Memory in Children

    ERIC Educational Resources Information Center

    Calfee, Robert C.

    1970-01-01

    A series of studies indicated that performance on serial recognition memory tasks was relatively constant over a wide range of age and IQ, and except for response biases and forgetting rate, recognition memory processes of normal and retarded children appeared to be identical with those of adults. (Author/DR)

  20. Sources of Interference in Recognition Testing

    ERIC Educational Resources Information Center

    Annis, Jeffrey; Malmberg, Kenneth J.; Criss, Amy H.; Shiffrin, Richard M.

    2013-01-01

    Recognition memory accuracy is harmed by prior testing (a.k.a., output interference [OI]; Tulving & Arbuckle, 1966). In several experiments, we interpolated various tasks between recognition test trials. The stimuli and the tasks were more similar (lexical decision [LD] of words and nonwords) or less similar (gender identification of male and…

  1. Object Recognition Memory and the Rodent Hippocampus

    ERIC Educational Resources Information Center

    Broadbent, Nicola J.; Gaskin, Stephane; Squire, Larry R.; Clark, Robert E.

    2010-01-01

    In rodents, the novel object recognition task (NOR) has become a benchmark task for assessing recognition memory. Yet, despite its widespread use, a consensus has not developed about which brain structures are important for task performance. We assessed both the anterograde and retrograde effects of hippocampal lesions on performance in the NOR…

  2. Discovery and Recognition of the Artistically Talented.

    ERIC Educational Resources Information Center

    Wenner, Gene C.

    1985-01-01

    The National Foundation for the Advancement of the Arts, a program designed to provide national recognition and support for artistically talented youth, sponsors the Arts Recognition and Talent Search Program (ARTS). ARTS addresses areas of theater, visual arts, writing, dance, and music. The judging process is described. (Author/CL)

  3. Rapid Naming Speed and Chinese Character Recognition

    ERIC Educational Resources Information Center

    Liao, Chen-Huei; Georgiou, George K.; Parrila, Rauno

    2008-01-01

    We examined the relationship between rapid naming speed (RAN) and Chinese character recognition accuracy and fluency. Sixty-three grade 2 and 54 grade 4 Taiwanese children were administered four RAN tasks (colors, digits, Zhu-Yin-Fu-Hao, characters), and two character recognition tasks. RAN tasks accounted for more reading variance in grade 4 than…

  4. Robotic CCD microscope for enhanced crystal recognition

    DOEpatents

    Segelke, Brent W.; Toppani, Dominique

    2007-11-06

    A robotic CCD microscope and procedures to automate crystal recognition. The robotic CCD microscope and procedures enables more accurate crystal recognition, leading to fewer false negative and fewer false positives, and enable detection of smaller crystals compared to other methods available today.

  5. Sleep Enhances Explicit Recollection in Recognition Memory

    ERIC Educational Resources Information Center

    Drosopoulos, Spyridon; Wagner, Ullrich; Born, Jan

    2005-01-01

    Recognition memory is considered to be supported by two different memory processes, i.e., the explicit recollection of information about a previous event and an implicit process of recognition based on a contextual sense of familiarity. Both types of memory supposedly rely on distinct memory systems. Sleep is known to enhance the consolidation of…

  6. Syllable Transposition Effects in Korean Word Recognition

    ERIC Educational Resources Information Center

    Lee, Chang H.; Kwon, Youan; Kim, Kyungil; Rastle, Kathleen

    2015-01-01

    Research on the impact of letter transpositions in visual word recognition has yielded important clues about the nature of orthographic representations. This study investigated the impact of syllable transpositions on the recognition of Korean multisyllabic words. Results showed that rejection latencies in visual lexical decision for…

  7. Cognitive Fatigue Facilitates Procedural Sequence Learning

    PubMed Central

    Borragán, Guillermo; Slama, Hichem; Destrebecqz, Arnaud; Peigneux, Philippe

    2016-01-01

    Enhanced procedural learning has been evidenced in conditions where cognitive control is diminished, including hypnosis, disruption of prefrontal activity and non-optimal time of the day. Another condition depleting the availability of controlled resources is cognitive fatigue (CF). We tested the hypothesis that CF, eventually leading to diminished cognitive control, facilitates procedural sequence learning. In a two-day experiment, 23 young healthy adults were administered a serial reaction time task (SRTT) following the induction of high or low levels of CF, in a counterbalanced order. CF was induced using the Time load Dual-back (TloadDback) paradigm, a dual working memory task that allows tailoring cognitive load levels to the individual’s optimal performance capacity. In line with our hypothesis, reaction times (RT) in the SRTT were faster in the high- than in the low-level fatigue condition, and performance improvement was higher for the sequential than the motor components. Altogether, our results suggest a paradoxical, facilitating impact of CF on procedural motor sequence learning. We propose that facilitated learning in the high-level fatigue condition stems from a reduction in the cognitive resources devoted to cognitive control processes that normally oppose automatic procedural acquisition mechanisms. PMID:26973501

  8. Chimpanzee lip-smacking facilitates cooperative behaviour

    PubMed Central

    Fedurek, Pawel; Slocombe, Katie E.; Hartel, Jessica A.; Zuberbühler, Klaus

    2015-01-01

    Signalling plays an important role in facilitating and maintaining affiliative or cooperative interactions in social animals. Social grooming in primates is an example of an interaction that requires coordination between partners but little is known about communicative behaviours facilitating this activity. In this study, we analysed the communication of wild chimpanzees of Budongo Forest, Uganda, as they entered and maintained a naturally occurring cooperative interaction: social grooming. We found that lip-smacking, a distinct multimodal oral gesture produced during grooming, coordinated this activity. Lip-smacking at the beginning of grooming bouts was significantly more often followed by longer and reciprocated bouts than silent grooming initiations. Lip-smacks were more likely to be produced when the risk of termination of the interaction by the recipient was high, for instance when grooming vulnerable body parts. Groomers were also more likely to produce lip-smacks during face-to-face grooming where the visual aspect of the signal could be perceived. Data are consistent with the hypothesis that chimpanzee lip-smacks function to coordinate and prolong social grooming, suggesting that this oral signal is an example of a communicative behaviour facilitating cooperative behaviour in chimpanzees. PMID:26293777

  9. Selective Activation of Microglia Facilitates Synaptic Strength

    PubMed Central

    Clark, Anna K.; Gruber-Schoffnegger, Doris; Drdla-Schutting, Ruth; Gerhold, Katharina J.; Malcangio, Marzia

    2015-01-01

    Synaptic plasticity is thought to be initiated by neurons only, with the prevailing view assigning glial cells mere specify supportive functions for synaptic transmission and plasticity. We now demonstrate that glial cells can control synaptic strength independent of neuronal activity. Here we show that selective activation of microglia in the rat is sufficient to rapidly facilitate synaptic strength between primary afferent C-fibers and lamina I neurons, the first synaptic relay in the nociceptive pathway. Specifically, the activation of the CX3CR1 receptor by fractalkine induces the release of interleukin-1β from microglia, which modulates NMDA signaling in postsynaptic neurons, leading to the release of an eicosanoid messenger, which ultimately enhances presynaptic neurotransmitter release. In contrast to the conventional view, this form of plasticity does not require enhanced neuronal activity to trigger the events leading to synaptic facilitation. Augmentation of synaptic strength in nociceptive pathways represents a cellular model of pain amplification. The present data thus suggest that, under chronic pain states, CX3CR1-mediated activation of microglia drives the facilitation of excitatory synaptic transmission in the dorsal horn, which contributes to pain hypersensitivity in chronic pain states. PMID:25788673

  10. Fluoxetine Facilitates Fear Extinction Through Amygdala Endocannabinoids

    PubMed Central

    Gunduz-Cinar, Ozge; Flynn, Shaun; Brockway, Emma; Kaugars, Katherine; Baldi, Rita; Ramikie, Teniel S; Cinar, Resat; Kunos, George; Patel, Sachin; Holmes, Andrew

    2016-01-01

    Pharmacologically elevating brain endocannabinoids (eCBs) share anxiolytic and fear extinction-facilitating properties with classical therapeutics, including the selective serotonin reuptake inhibitor, fluoxetine. There are also known functional interactions between the eCB and serotonin systems and preliminary evidence that antidepressants cause alterations in brain eCBs. However, the potential role of eCBs in mediating the facilitatory effects of fluoxetine on fear extinction has not been established. Here, to test for a possible mechanistic contribution of eCBs to fluoxetine's proextinction effects, we integrated biochemical, electrophysiological, pharmacological, and behavioral techniques, using the extinction-impaired 129S1/Sv1mJ mouse strain. Chronic fluoxetine treatment produced a significant and selective increase in levels of anandamide in the BLA, and an associated decrease in activity of the anandamide-catabolizing enzyme, fatty acid amide hydrolase. Slice electrophysiological recordings showed that fluoxetine-induced increases in anandamide were associated with the amplification of eCB-mediated tonic constraint of inhibitory, but not excitatory, transmission in the BLA. Behaviorally, chronic fluoxetine facilitated extinction retrieval in a manner that was prevented by systemic or BLA-specific blockade of CB1 receptors. In contrast to fluoxetine, citalopram treatment did not increase BLA eCBs or facilitate extinction. Taken together, these findings reveal a novel, obligatory role for amygdala eCBs in the proextinction effects of a major pharmacotherapy for trauma- and stressor-related disorders and anxiety disorders. PMID:26514583

  11. Orthography facilitates vocabulary learning for children with autism spectrum disorders (ASD).

    PubMed

    Lucas, Rebecca; Norbury, Courtenay Frazier

    2014-01-01

    This study investigated the extent to which children with autism spectrum disorders (ASD) can use orthography to facilitate vocabulary learning, as is the case for typically developing (TD) children. Forty-one children aged 7-12 years, 20 with a formal diagnosis of ASD and 21 TD peers, were taught 16 low-frequency concrete science words, such as "breccia". Half of the stimuli had the written word presented alongside a picture of the target item (orthography present: OP) while the remaining items were taught with orthography absent (OA). During the learning phase, eye movements were recorded; there were no group differences in the time spent fixating the written form. Production, comprehension, and recognition of orthographic forms of new words were assessed immediately after learning and again after a 24-hour delay. The vocabulary learning of both groups was facilitated by the presence of orthography. Overall, the groups did not differ in comprehension of new words or recognition of new orthographic forms, although the children with ASD demonstrated superior phonological learning (as measured by a picture naming task) relative to TD peers. Additionally, both groups retained or increased new knowledge after 24 hours. The results suggest that presenting the written form during oral vocabulary teaching will enhance learning and provide a mechanism for children with ASD to increase word knowledge despite potential limitations in social learning. PMID:24313313

  12. Orthography facilitates vocabulary learning for children with autism spectrum disorders (ASD).

    PubMed

    Lucas, Rebecca; Norbury, Courtenay Frazier

    2014-01-01

    This study investigated the extent to which children with autism spectrum disorders (ASD) can use orthography to facilitate vocabulary learning, as is the case for typically developing (TD) children. Forty-one children aged 7-12 years, 20 with a formal diagnosis of ASD and 21 TD peers, were taught 16 low-frequency concrete science words, such as "breccia". Half of the stimuli had the written word presented alongside a picture of the target item (orthography present: OP) while the remaining items were taught with orthography absent (OA). During the learning phase, eye movements were recorded; there were no group differences in the time spent fixating the written form. Production, comprehension, and recognition of orthographic forms of new words were assessed immediately after learning and again after a 24-hour delay. The vocabulary learning of both groups was facilitated by the presence of orthography. Overall, the groups did not differ in comprehension of new words or recognition of new orthographic forms, although the children with ASD demonstrated superior phonological learning (as measured by a picture naming task) relative to TD peers. Additionally, both groups retained or increased new knowledge after 24 hours. The results suggest that presenting the written form during oral vocabulary teaching will enhance learning and provide a mechanism for children with ASD to increase word knowledge despite potential limitations in social learning.

  13. HMGB1 interacts with XPA to facilitate the processing of DNA interstrand crosslinks in human cells

    PubMed Central

    Mukherjee, Anirban; Vasquez, Karen M.

    2016-01-01

    Many effective agents used in cancer chemotherapy cause DNA interstrand crosslinks (ICLs), which covalently link both strands of the double helix together resulting in cytotoxicity. ICLs are thought to be processed by proteins from a variety of DNA repair pathways; however, a clear understanding of ICL recognition and repair processing in human cells is lacking. Previously, we found that the high mobility group box 1 (HMGB1) protein bound to triplex-directed psoralen ICLs (TFO-ICLs) in vitro, cooperatively with NER damage recognition proteins, promoted removal of UVC-induced lesions and facilitated error-free repair of TFO-ICLs in mouse fibroblasts. Here, we demonstrate that HMGB1 recognizes TFO-ICLs in human cells, and its depletion increases ICL-induced mutagenesis in human cells without altering the mutation spectra. In contrast, HMGB1 depletion in XPA-deficient human cells significantly altered the ICL-induced mutation spectrum from predominantly T→A to T→G transversions. Moreover, the recruitment of XPA and HMGB1 to the ICLs is co-dependent. Finally, we show that HMGB1 specifically introduces negative supercoils in ICL-containing plasmids in HeLa cell extracts. Taken together, our data suggest that in human cells, HMGB1 functions in association with XPA on ICLs and facilitates the formation of a favorable architectural environment for ICL repair processing. PMID:26578599

  14. A Component-Based Vocabulary-Extensible Sign Language Gesture Recognition Framework.

    PubMed

    Wei, Shengjing; Chen, Xiang; Yang, Xidong; Cao, Shuai; Zhang, Xu

    2016-01-01

    Sign language recognition (SLR) can provide a helpful tool for the communication between the deaf and the external world. This paper proposed a component-based vocabulary extensible SLR framework using data from surface electromyographic (sEMG) sensors, accelerometers (ACC), and gyroscopes (GYRO). In this framework, a sign word was considered to be a combination of five common sign components, including hand shape, axis, orientation, rotation, and trajectory, and sign classification was implemented based on the recognition of five components. Especially, the proposed SLR framework consisted of two major parts. The first part was to obtain the component-based form of sign gestures and establish the code table of target sign gesture set using data from a reference subject. In the second part, which was designed for new users, component classifiers were trained using a training set suggested by the reference subject and the classification of unknown gestures was performed with a code matching method. Five subjects participated in this study and recognition experiments under different size of training sets were implemented on a target gesture set consisting of 110 frequently-used Chinese Sign Language (CSL) sign words. The experimental results demonstrated that the proposed framework can realize large-scale gesture set recognition with a small-scale training set. With the smallest training sets (containing about one-third gestures of the target gesture set) suggested by two reference subjects, (82.6 ± 13.2)% and (79.7 ± 13.4)% average recognition accuracy were obtained for 110 words respectively, and the average recognition accuracy climbed up to (88 ± 13.7)% and (86.3 ± 13.7)% when the training set included 50~60 gestures (about half of the target gesture set). The proposed framework can significantly reduce the user's training burden in large-scale gesture recognition, which will facilitate the implementation of a practical SLR system. PMID:27104534

  15. Age, gender, and puberty influence the development of facial emotion recognition.

    PubMed

    Lawrence, Kate; Campbell, Ruth; Skuse, David

    2015-01-01

    Our ability to differentiate between simple facial expressions of emotion develops between infancy and early adulthood, yet few studies have explored the developmental trajectory of emotion recognition using a single methodology across a wide age-range. We investigated the development of emotion recognition abilities through childhood and adolescence, testing the hypothesis that children's ability to recognize simple emotions is modulated by chronological age, pubertal stage and gender. In order to establish norms, we assessed 478 children aged 6-16 years, using the Ekman-Friesen Pictures of Facial Affect. We then modeled these cross-sectional data in terms of competence in accurate recognition of the six emotions studied, when the positive correlation between emotion recognition and IQ was controlled. Significant linear trends were seen in children's ability to recognize facial expressions of happiness, surprise, fear, and disgust; there was improvement with increasing age. In contrast, for sad and angry expressions there is little or no change in accuracy over the age range 6-16 years; near-adult levels of competence are established by middle-childhood. In a sampled subset, pubertal status influenced the ability to recognize facial expressions of disgust and anger; there was an increase in competence from mid to late puberty, which occurred independently of age. A small female advantage was found in the recognition of some facial expressions. The normative data provided in this study will aid clinicians and researchers in assessing the emotion recognition abilities of children and will facilitate the identification of abnormalities in a skill that is often impaired in neurodevelopmental disorders. If emotion recognition abilities are a good model with which to understand adolescent development, then these results could have implications for the education, mental health provision and legal treatment of teenagers. PMID:26136697

  16. Age, gender, and puberty influence the development of facial emotion recognition

    PubMed Central

    Lawrence, Kate; Campbell, Ruth; Skuse, David

    2015-01-01

    Our ability to differentiate between simple facial expressions of emotion develops between infancy and early adulthood, yet few studies have explored the developmental trajectory of emotion recognition using a single methodology across a wide age-range. We investigated the development of emotion recognition abilities through childhood and adolescence, testing the hypothesis that children’s ability to recognize simple emotions is modulated by chronological age, pubertal stage and gender. In order to establish norms, we assessed 478 children aged 6–16 years, using the Ekman-Friesen Pictures of Facial Affect. We then modeled these cross-sectional data in terms of competence in accurate recognition of the six emotions studied, when the positive correlation between emotion recognition and IQ was controlled. Significant linear trends were seen in children’s ability to recognize facial expressions of happiness, surprise, fear, and disgust; there was improvement with increasing age. In contrast, for sad and angry expressions there is little or no change in accuracy over the age range 6–16 years; near-adult levels of competence are established by middle-childhood. In a sampled subset, pubertal status influenced the ability to recognize facial expressions of disgust and anger; there was an increase in competence from mid to late puberty, which occurred independently of age. A small female advantage was found in the recognition of some facial expressions. The normative data provided in this study will aid clinicians and researchers in assessing the emotion recognition abilities of children and will facilitate the identification of abnormalities in a skill that is often impaired in neurodevelopmental disorders. If emotion recognition abilities are a good model with which to understand adolescent development, then these results could have implications for the education, mental health provision and legal treatment of teenagers. PMID:26136697

  17. Articulation effects in melody recognition memory.

    PubMed

    Wee Hun Lim, Stephen; Goh, Winston D

    2013-09-01

    Various surface features-timbre, tempo, and pitch-influence melody recognition memory, but articulation format effects, if any, remain unknown. For the first time, these effects were examined. In Experiment 1, melodies that remained in the same, or appeared in a different but similar, articulation format from study to test were recognized better than were melodies that were presented in a distinct format at test. A similar articulation format adequately induced matching processes to enhance recognition. Experiment 2 revealed that melodies rated as perceptually dissimilar on the basis of the location of the articulation mismatch did not impair recognition performance, suggesting an important boundary condition for articulation format effects on memory recognition-the matching of the memory trace and recognition probe may depend more on the overall proportion, rather than the temporal location, of the mismatch. The present findings are discussed in terms of a global matching advantage hypothesis. PMID:23410265

  18. Review of chart recognition in document images

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Lu, Xiaoqing; Qin, Yeyang; Tang, Zhi; Xu, Jianbo

    2013-01-01

    As an effective information transmitting way, chart is widely used to represent scientific statistics datum in books, research papers, newspapers etc. Though textual information is still the major source of data, there has been an increasing trend of introducing graphs, pictures, and figures into the information pool. Text recognition techniques for documents have been accomplished using optical character recognition (OCR) software. Chart recognition techniques as a necessary supplement of OCR for document images are still an unsolved problem due to the great subjectiveness and variety of charts styles. This paper reviews the development process of chart recognition techniques in the past decades and presents the focuses of current researches. The whole process of chart recognition is presented systematically, which mainly includes three parts: chart segmentation, chart classification, and chart Interpretation. In each part, the latest research work is introduced. In the last, the paper concludes with a summary and promising future research direction.

  19. Modal-Power-Based Haptic Motion Recognition

    NASA Astrophysics Data System (ADS)

    Kasahara, Yusuke; Shimono, Tomoyuki; Kuwahara, Hiroaki; Sato, Masataka; Ohnishi, Kouhei

    Motion recognition based on sensory information is important for providing assistance to human using robots. Several studies have been carried out on motion recognition based on image information. However, in the motion of humans contact with an object can not be evaluated precisely by image-based recognition. This is because the considering force information is very important for describing contact motion. In this paper, a modal-power-based haptic motion recognition is proposed; modal power is considered to reveal information on both position and force. Modal power is considered to be one of the defining features of human motion. A motion recognition algorithm based on linear discriminant analysis is proposed to distinguish between similar motions. Haptic information is extracted using a bilateral master-slave system. Then, the observed motion is decomposed in terms of primitive functions in a modal space. The experimental results show the effectiveness of the proposed method.

  20. Gender recognition from point-light walkers.

    PubMed

    Pollick, Frank E; Kay, Jim W; Heim, Katrin; Stringer, Rebecca

    2005-12-01

    Point-light displays of human gait provide information sufficient to recognize the gender of a walker and are taken as evidence of the exquisite tuning of the visual system to biological motion. The authors revisit this topic with the goals of quantifying human efficiency at gender recognition. To achieve this, the authors first derive an ideal observer for gender recognition on the basis of center of moment (J. E. Cutting, D. R. Proffitt, & L. T. Kozlowski, 1978) and, with the use of anthropometric data from various populations, show optimal recognition of approximately 79% correct. Next, they perform a meta-analysis of 21 experiments examining gender recognition, obtaining accuracies of 66% correct for a side view and 71% for other views. Finally, results of the meta-analysis and the ideal observer are combined to obtain estimates of human efficiency at gender recognition of 26% for the side view and 47% for other views. PMID:16366787