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Sample records for recognition molecules involved

  1. Single-Molecule View of Small RNA-Guided Target Search and Recognition.

    Science.gov (United States)

    Globyte, Viktorija; Kim, Sung Hyun; Joo, Chirlmin

    2018-05-20

    Most everyday processes in life involve a necessity for an entity to locate its target. On a cellular level, many proteins have to find their target to perform their function. From gene-expression regulation to DNA repair to host defense, numerous nucleic acid-interacting proteins use distinct target search mechanisms. Several proteins achieve that with the help of short RNA strands known as guides. This review focuses on single-molecule advances studying the target search and recognition mechanism of Argonaute and CRISPR (clustered regularly interspaced short palindromic repeats) systems. We discuss different steps involved in search and recognition, from the initial complex prearrangement into the target-search competent state to the final proofreading steps. We focus on target search mechanisms that range from weak interactions, to one- and three-dimensional diffusion, to conformational proofreading. We compare the mechanisms of Argonaute and CRISPR with a well-studied target search system, RecA.

  2. DMPD: CD14 and other recognition molecules for lipopolysaccharide: a review. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 7542643 CD14 and other recognition molecules for lipopolysaccharide: a review. Kiel...her recognition molecules for lipopolysaccharide: a review. PubmedID 7542643 Title CD14 and other recognitio...n molecules for lipopolysaccharide: a review. Authors Kielian TL, Blecha F. Publi

  3. Interactions of the humoral pattern recognition molecule PTX3 with the complement system

    DEFF Research Database (Denmark)

    Doni, Andrea; Garlanda, Cecilia; Bottazzi, Barbara

    2012-01-01

    The innate immune system comprises a cellular and a humoral arm. The long pentraxin PTX3 is a fluid phase pattern recognition molecule, which acts as an essential component of the humoral arm of innate immunity. PTX3 has antibody-like properties including interactions with complement components....... PTX3 interacts with C1q, ficolin-1 and ficolin-2 as well as mannose-binding lectin, recognition molecules in the classical and lectin complement pathways. The formation of these heterocomplexes results in cooperative pathogen recognition and complement activation. Interactions with C4b binding protein...

  4. CL-L1 and CL-K1 and other complement associated pattern recognition molecules in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Troldborg, Anne; Thiel, Steffen; Jensen, Lisbeth

    2015-01-01

    The objective of this study was to explore the involvement of collectin liver 1 (CL-L1) and collectin kidney 1 (CL-K1) and other pattern recognition molecules (PRMs) of the lectin pathway of the complement system in a cross-sectional cohort of systemic lupus erythematosus (SLE) patients...

  5. Immune receptors involved in Streptococcus suis recognition by dendritic cells.

    Directory of Open Access Journals (Sweden)

    Marie-Pier Lecours

    Full Text Available Streptococcus suis is an important swine pathogen and an emerging zoonotic agent of septicemia and meningitis. Knowledge on host immune responses towards S. suis, and strategies used by this pathogen for subversion of these responses is scarce. The objective of this study was to identify the immune receptors involved in S. suis recognition by dendritic cells (DCs. Production of cytokines and expression of co-stimulatory molecules by DCs were shown to strongly rely on MyD88-dependent signaling pathways, suggesting that DCs recognize S. suis and become activated mostly through Toll-like receptor (TLR signaling. Supporting this fact, TLR2(-/- DCs were severely impaired in the release of several cytokines and the surface expression of CD86 and MHC-II. The release of IL-12p70 and CXC10, and the expression of CD40 were found to depend on signaling by both TLR2 and TLR9. The release of IL-23 and CXCL1 were partially dependent on NOD2. Finally, despite the fact that MyD88 signaling was crucial for DC activation and maturation, MyD88-dependent pathways were not implicated in S. suis internalization by DCs. This first study on receptors involved in DC activation by S. suis suggests a major involvement of MyD88 signaling pathways, mainly (but not exclusively through TLR2. A multimodal recognition involving a combination of different receptors seems essential for DC effective response to S. suis.

  6. MHC class I molecules with superenhanced CD8 binding properties bypass the requirement for cognate TCR recognition and nonspecifically activate CTLs

    NARCIS (Netherlands)

    L. Wooldridge (Linda); M. Clement (Mathew); A. Lissina (Anna); E.S.J. Edwards (Emily); K. Ladell (Kristin); J. Ekeruche (Julia); R.E. Hewitt (Rachel); B. Laugel (Bruno); E. Gostick (Emma); D.K. Cole (David); J.E.M.A. Debets (Reno); C.A. Berrevoets (Cor); J.J. Miles (John); S.R. Burrows (Scott); D.A. Price (David); A.K. Sewell (Andrew)

    2010-01-01

    textabstractCD8+CTLs are essential for effective immune defense against intracellular microbes and neoplasia. CTLs recognize short peptide fragments presented in association with MHC class I (MHCI) molecules on the surface of infected or dysregulated cells. Ag recognition involves the binding of

  7. Simple test system for single molecule recognition force microscopy

    International Nuclear Information System (INIS)

    Riener, Christian K.; Stroh, Cordula M.; Ebner, Andreas; Klampfl, Christian; Gall, Alex A.; Romanin, Christoph; Lyubchenko, Yuri L.; Hinterdorfer, Peter; Gruber, Hermann J.

    2003-01-01

    We have established an easy-to-use test system for detecting receptor-ligand interactions on the single molecule level using atomic force microscopy (AFM). For this, avidin-biotin, probably the best characterized receptor-ligand pair, was chosen. AFM sensors were prepared containing tethered biotin molecules at sufficiently low surface concentrations appropriate for single molecule studies. A biotin tether, consisting of a 6 nm poly(ethylene glycol) (PEG) chain and a functional succinimide group at the other end, was newly synthesized and covalently coupled to amine-functionalized AFM tips. In particular, PEG 800 diamine was glutarylated, the mono-adduct NH 2 -PEG-COOH was isolated by ion exchange chromatography and reacted with biotin succinimidylester to give biotin-PEG-COOH which was then activated as N-hydroxysuccinimide (NHS) ester to give the biotin-PEG-NHS conjugate which was coupled to the aminofunctionalized AFM tip. The motional freedom provided by PEG allows for free rotation of the biotin molecule on the AFM sensor and for specific binding to avidin which had been adsorbed to mica surfaces via electrostatic interactions. Specific avidin-biotin recognition events were discriminated from nonspecific tip-mica adhesion by their typical unbinding force (∼40 pN at 1.4 nN/s loading rate), unbinding length (<13 nm), the characteristic nonlinear force-distance relation of the PEG linker, and by specific block with excess of free d-biotin. The convenience of the test system allowed to evaluate, and compare, different methods and conditions of tip aminofunctionalization with respect to specific binding and nonspecific adhesion. It is concluded that this system is well suited as calibration or start-up kit for single molecule recognition force microscopy

  8. Ficolins and FIBCD1: Soluble and membrane bound pattern recognition molecules with acetyl group selectivity

    DEFF Research Database (Denmark)

    Thomsen, Theresa; Schlosser, Anders; Holmskov, Uffe

    2011-01-01

    as pattern recognition molecules. Ficolins are soluble oligomeric proteins composed of trimeric collagen-like regions linked to fibrinogen-related domains (FReDs) that have the ability to sense molecular patterns on both pathogens and apoptotic cell surfaces and activate the complement system. The ficolins......D-containing molecules, and discusses structural resemblance but also diversity in recognition of acetylated ligands....

  9. Fast recognition of single molecules based on single-event photon statistics

    International Nuclear Information System (INIS)

    Dong Shuangli; Huang Tao; Liu Yuan; Wang Jun; Zhang Guofeng; Xiao Liantuan; Jia Suotang

    2007-01-01

    Mandel's Q parameter, which is determined from single-event photon statistics, provides an alternative way to recognize single molecules with fluorescence detection, other than the second-order correlation function. It is shown that the Q parameter of an assumed ideal double-molecule fluorescence with the same average photon number as that of the sample fluorescence can act as the criterion for single-molecule recognition. The influence of signal-to-background ratio and the error estimates for photon statistics are also presented. We have applied this method to ascertain single Cy5 dye molecules within hundreds of milliseconds

  10. Single-molecule spectroscopy of amino acids and peptides by recognition tunnelling

    Science.gov (United States)

    Zhao, Yanan; Ashcroft, Brian; Zhang, Peiming; Liu, Hao; Sen, Suman; Song, Weisi; Im, Jongone; Gyarfas, Brett; Manna, Saikat; Biswas, Sovan; Borges, Chad; Lindsay, Stuart

    2014-06-01

    The human proteome has millions of protein variants due to alternative RNA splicing and post-translational modifications, and variants that are related to diseases are frequently present in minute concentrations. For DNA and RNA, low concentrations can be amplified using the polymerase chain reaction, but there is no such reaction for proteins. Therefore, the development of single-molecule protein sequencing is a critical step in the search for protein biomarkers. Here, we show that single amino acids can be identified by trapping the molecules between two electrodes that are coated with a layer of recognition molecules, then measuring the electron tunnelling current across the junction. A given molecule can bind in more than one way in the junction, and we therefore use a machine-learning algorithm to distinguish between the sets of electronic `fingerprints' associated with each binding motif. With this recognition tunnelling technique, we are able to identify D and L enantiomers, a methylated amino acid, isobaric isomers and short peptides. The results suggest that direct electronic sequencing of single proteins could be possible by sequentially measuring the products of processive exopeptidase digestion, or by using a molecular motor to pull proteins through a tunnel junction integrated with a nanopore.

  11. Self-Assembled Core-Satellite Gold Nanoparticle Networks for Ultrasensitive Detection of Chiral Molecules by Recognition Tunneling Current.

    Science.gov (United States)

    Zhang, Yuanchao; Liu, Jingquan; Li, Da; Dai, Xing; Yan, Fuhua; Conlan, Xavier A; Zhou, Ruhong; Barrow, Colin J; He, Jin; Wang, Xin; Yang, Wenrong

    2016-05-24

    Chirality sensing is a very challenging task. Here, we report a method for ultrasensitive detection of chiral molecule l/d-carnitine based on changes in the recognition tunneling current across self-assembled core-satellite gold nanoparticle (GNP) networks. The recognition tunneling technique has been demonstrated to work at the single molecule level where the binding between the reader molecules and the analytes in a nanojunction. This process was observed to generate a unique and sensitive change in tunneling current, which can be used to identify the analytes of interest. The molecular recognition mechanism between amino acid l-cysteine and l/d-carnitine has been studied with the aid of SERS. The different binding strength between homo- or heterochiral pairs can be effectively probed by the copper ion replacement fracture. The device resistance was measured before and after the sequential exposures to l/d-carnitine and copper ions. The normalized resistance change was found to be extremely sensitive to the chirality of carnitine molecule. The results suggested that a GNP networks device optimized for recognition tunneling was successfully built and that such a device can be used for ultrasensitive detection of chiral molecules.

  12. NATO Advanced Research Workshop on Chemosensors of Ion and Molecule Recognition

    CERN Document Server

    Czarnik, A

    1997-01-01

    In the broad field of supramolecular chemistry, the design and hence the use of chemosensors for ion and molecule recognition have developed at an extroardinary rate. This imaginative and creative area which involves the interface of different disciplines, e.g. organic and inorganic chemistry, physical chemistry, biology, medicine, environmental science, is not only fundamental in nature. It is also clear that progress is most rewarding for several new sensor applications deriving from the specific signal delivered by the analyte-probe interaction. Indeed, if calcium sensing in real time for biological purposes is actually possible, owing to the emergence of efficient fluorescent receptors, other elements can also be specifically detected, identified and finally titrated using tailored chemosensors. Pollutants such as heavy metals or radionuclides are among the main targets since their detection and removal could be envisioned at very low concentrations with, in addition, sensors displaying specific and stron...

  13. Complement activating soluble pattern recognition molecules with collagen-like regions, mannan-binding lectin, ficolins and associated proteins

    DEFF Research Database (Denmark)

    Thiel, Steffen

    2007-01-01

    Mannan-binding lectin (MBL), L-ficolin, M-ficolin and H-ficolin are all complement activating soluble pattern recognition molecules with recognition domains linked to collagen-like regions. All four may form complexes with four structurally related proteins, the three MBL-associated serine...... proteases (MASPs), MASP-1, MASP-2 and MASP-3, and a smaller MBL-associated protein (MAp19). The four recognition molecules recognize patterns of carbohydrate or acetyl-group containing ligands. After binding to the relevant targets all four are able to activate the complement system. We thus have a system...... where four different and/or overlapping patterns of microbial origin or patterns of altered-self may be recognized, but in all cases the signalling molecules, the MASPs, are shared. MASP-1 and MASP-3 are formed from one gene, MASP1/3, by alternative splicing generating two different mRNAs from a single...

  14. Investigations into the involvement of NMDA mechanisms in recognition memory.

    Science.gov (United States)

    Warburton, E Clea; Barker, Gareth R I; Brown, Malcom W

    2013-11-01

    This review will focus on evidence showing that NMDA receptor neurotransmission is critical for synaptic plasticity processes within brain regions known to be necessary for the formation of object recognition memories. The aim will be to provide evidence concerning NMDA mechanisms related to recognition memory processes and show that recognition memory for objects, places or associations between objects and places depends on NMDA neurotransmission within the perirhinal cortex, temporal association cortex medial prefrontal cortex and hippocampus. Administration of the NMDA antagonist AP5, selectively into each of these brain regions has revealed that the extent of the involvement NMDA receptors appears dependent on the type of information required to solve the recognition memory task; thus NMDA receptors in the perirhinal cortex are crucial for the encoding of long-term recognition memory for objects, and object-in-place associations, but not for short-term recognition memory or for retrieval. In contrast the hippocampus and medial prefrontal cortex are required for both long-term and short-term recognition memory for places or associations between objects and places, or for recognition memory tasks that have a temporal component. Such studies have therefore confirmed that the multiple brain regions make distinct contributions to recognition memory but in addition that more than one synaptic plasticity process must be involved. This article is part of the Special Issue entitled 'Glutamate Receptor-Dependent Synaptic Plasticity'. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Natural Cytotoxicity Receptors: Pattern Recognition and Involvement of Carbohydrates

    Directory of Open Access Journals (Sweden)

    Angel Porgador

    2005-01-01

    Full Text Available Natural cytotoxicity receptors (NCRs, expressed by natural killer (NK cells, trigger NK lysis of tumor and virus-infected cells on interaction with cell-surface ligands of these target cells. We have determined that viral hemagglutinins expressed on the surface of virus-infected cells are involved in the recognition by the NCRs, NKp44 and NKp46. Recognition of tumor cells by the NCRs NKp30 and NKp46 involves heparan sulfate epitopes expressed on the tumor cell membrane. Our studies provide new evidence for the identity of the ligands for NCRs and indicate that a broader definition should be applied to pathological patterns recognized by innate immune receptors. Since nonmicrobial endogenous carbohydrate structures contribute significantly to this recognition, there is an imperative need to develop appropriate tools for the facile sequencing of carbohydrate moieties.

  16. Assay for the pattern recognition molecule collectin liver 1 (CL-L1)

    DEFF Research Database (Denmark)

    Axelgaard, Esben; Jensenius, Jens Christian; Thiel, Steffen

    Collectin liver 1 (also termed collectin 10 and CL-L1) is a C-type lectin that functions as a pattern recognition molecule (PRM) in the innate immune system1. We have produced antibodies against CL-L1 and have developed a sandwich-type time-resolved immuno-fluorometric assay (TRIFMA...... to co-purify with MASPs, possibly rendering it a role in complement. CL-L1 showed binding activity towards mannose-TSK beads in a Ca2+-dependent manner. This binding could be inhibited by mannose and glucose, but not by galactose, indicating that CL-L1 binds via its carbohydrate-recognition domain (CRD)....

  17. Electronic single-molecule identification of carbohydrate isomers by recognition tunnelling

    Science.gov (United States)

    Im, Jongone; Biswas, Sovan; Liu, Hao; Zhao, Yanan; Sen, Suman; Biswas, Sudipta; Ashcroft, Brian; Borges, Chad; Wang, Xu; Lindsay, Stuart; Zhang, Peiming

    2016-12-01

    Carbohydrates are one of the four main building blocks of life, and are categorized as monosaccharides (sugars), oligosaccharides and polysaccharides. Each sugar can exist in two alternative anomers (in which a hydroxy group at C-1 takes different orientations) and each pair of sugars can form different epimers (isomers around the stereocentres connecting the sugars). This leads to a vast combinatorial complexity, intractable to mass spectrometry and requiring large amounts of sample for NMR characterization. Combining measurements of collision cross section with mass spectrometry (IM-MS) helps, but many isomers are still difficult to separate. Here, we show that recognition tunnelling (RT) can classify many anomers and epimers via the current fluctuations they produce when captured in a tunnel junction functionalized with recognition molecules. Most importantly, RT is a nanoscale technique utilizing sub-picomole quantities of analyte. If integrated into a nanopore, RT would provide a unique approach to sequencing linear polysaccharides.

  18. Estrogenic involvement in social learning, social recognition and pathogen avoidance.

    Science.gov (United States)

    Choleris, Elena; Clipperton-Allen, Amy E; Phan, Anna; Valsecchi, Paola; Kavaliers, Martin

    2012-04-01

    Sociality comes with specific cognitive skills that allow the proper processing of information about others (social recognition), as well as of information originating from others (social learning). Because sociality and social interactions can also facilitate the spread of infection among individuals the ability to recognize and avoid pathogen threat is also essential. We review here various studies primarily from the rodent literature supporting estrogenic involvement in the regulation of social recognition, social learning (socially acquired food preferences and mate choice copying) and the recognition and avoidance of infected and potentially infected individuals. We consider both genomic and rapid estrogenic effects involving estrogen receptors α and β, and G-protein coupled estrogen receptor 1, along with their interactions with neuropeptide systems in the processing of social stimuli and the regulation and expression of these various socially relevant behaviors. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. New protein involved in the replacement of cell molecules

    DEFF Research Database (Denmark)

    Poulsen, Jesper Buchhave

    2011-01-01

    In collaboration with colleagues from La Trobe University, Australia, scientists at Aarhus University have discovered and defined a novel enzyme involved in the replacement and renewal of cell molecules. The enzyme exerts its function within the so-called mitochondria - small “enclosed” compartme......In collaboration with colleagues from La Trobe University, Australia, scientists at Aarhus University have discovered and defined a novel enzyme involved in the replacement and renewal of cell molecules. The enzyme exerts its function within the so-called mitochondria - small “enclosed...

  20. Insular Cortex Is Involved in Consolidation of Object Recognition Memory

    Science.gov (United States)

    Bermudez-Rattoni, Federico; Okuda, Shoki; Roozendaal, Benno; McGaugh, James L.

    2005-01-01

    Extensive evidence indicates that the insular cortex (IC), also termed gustatory cortex, is critically involved in conditioned taste aversion and taste recognition memory. Although most studies of the involvement of the IC in memory have investigated taste, there is some evidence that the IC is involved in memory that is not based on taste. In…

  1. СHIRAL RECOGNITION OF CYSTEINE MOLECULES BY CHIRAL CdSe AND CdS QUANTUM DOTS

    Directory of Open Access Journals (Sweden)

    M. V. Mukhina

    2015-11-01

    Full Text Available Here, we report the investigation of mechanism of chiral molecular recognition of cysteine biomolecules by chiral CdSe and CdS semiconductor nanocrystals. To observe chiral recognition process, we prepared enantioenriched ensembles of the nanocrystals capped with achiral ligand. The enantioenriched samples of intrinsically chiral CdSe quantum dots were prepared by separation of initial racemic mixture of the nanocrystals using chiral phase transfer from chloroform to water driven by L- and D-cysteine. Chiral molecules of cysteine and penicillamine were substituted for achiral molecules of dodecanethiol on the surfaces of CdSe and CdS samples, respectively, via reverse phase transfer from water to chloroform. We estimated an efficiency of the hetero- (d-L or l-D and homocomplexes (l-L formation by comparing the extents of corresponding complexing reactions. Using circular dichroism spectroscopy data we show an ability of nanocrystals enantiomers to discriminate between left-handed and right-handed enantiomers of biomolecules via preferential formation of heterocomplexes. Development of approaches for obtaining chiral nanocrystals via chiral phase transfer offers opportunities for investigation of molecular recognition at the nano/bio interfaces.

  2. Heme as a danger molecule in pathogen recognition.

    Science.gov (United States)

    Wegiel, Barbara; Hauser, Carl J; Otterbein, Leo E

    2015-12-01

    Appropriate control of redox mechanisms are critical for and effective innate immune response, which employs multiple cell types, receptors and molecules that recognize danger signals when they reach the host. Recognition of pathogen-associated pattern molecules (PAMPs) is a fundamental host survival mechanism for efficient elimination of invading pathogens and resolution of the infection and inflammation. In addition to PAMPs, eukaryotic cells contain a plethora of intracellular molecules that are normally secured within the confines of the plasma membrane, but if liberated and encountered in the extracellular milieu can provoke rapid cell activation. These are known as Alarmins or Danger-Associated Molecular Patterns (DAMPs) and can be released actively by cells or passively as a result of sterile cellular injury after trauma, ischemia, or toxin-induced cell rupture. Both PAMPs and DAMPs are recognized by a series of cognate receptors that increase the generation of free radicals and activate specific signaling pathways that result in regulation of a variety of stress response, redox sensitive genes. Multiple mediators released, as cells die include, but are not limited to ATP, hydrogen peroxide, heme, formyl peptides, DNA or mitochondria provide the second signal to amplify immune responses. In this review, we will focus on how sterile and infective stimuli activate the stress response gene heme oxygenase-1 (Hmox1, HO-1), a master gene critical to an appropriate host response that is now recognized as one with enormous therapeutic potential. HO-1 gene expression is regulated in large part by redox-sensitive proteins including but not limited to nrf2. Both PAMPs and DAMPs increase the activation of nrf2 and HO-1. Heme is a powerful pro-oxidant and as such should be qualified as a DAMP. With its degradation by HO-1a molecule of carbon monoxide (CO) is generated that in turn serves as a bioactive signaling molecule. PAMPs such as bacterial endotoxin activate HO-1

  3. Extracellular Molecules Involved in Cancer Cell Invasion

    International Nuclear Information System (INIS)

    Stivarou, Theodora; Patsavoudi, Evangelia

    2015-01-01

    Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion

  4. Extracellular Molecules Involved in Cancer Cell Invasion

    Directory of Open Access Journals (Sweden)

    Theodora Stivarou

    2015-01-01

    Full Text Available Nowadays it is perfectly clear that understanding and eradicating cancer cell invasion and metastasis represent the crucial, definitive points in cancer therapeutics. During the last two decades there has been a great interest in the understanding of the extracellular molecular mechanisms involved in cancer cell invasion. In this review, we highlight the findings concerning these processes, focusing in particular on extracellular molecules, including extracellular matrix proteins and their receptors, growth factors and their receptors, matrix metalloproteinases and extracellular chaperones. We report the molecular mechanisms underlying the important contribution of this pool of molecules to the complex, multi-step phenomenon of cancer cell invasion.

  5. Molecular tips for scanning tunneling microscopy: intermolecular electron tunneling for single-molecule recognition and electronics.

    Science.gov (United States)

    Nishino, Tomoaki

    2014-01-01

    This paper reviews the development of molecular tips for scanning tunneling microscopy (STM). Molecular tips offer many advantages: first is their ability to perform chemically selective imaging because of chemical interactions between the sample and the molecular tip, thus improving a major drawback of conventional STM. Rational design of the molecular tip allows sophisticated chemical recognition; e.g., chiral recognition and selective visualization of atomic defects in carbon nanotubes. Another advantage is that they provide a unique method to quantify electron transfer between single molecules. Understanding such electron transfer is mandatory for the realization of molecular electronics.

  6. Does Sport Event Involvement Influence Brand Recognition of Official Sponsors and Ambush Marketers?

    Directory of Open Access Journals (Sweden)

    Piątkowska Monika

    2016-12-01

    Full Text Available The main aim of the study is to verify how event involvement in the UEFA Euro 2012 influenced the recognition of both sponsors’ and ambushers’ brands. Computer-Assisted Personal Interviews were conducted on a representative sample of the Polish society (N = 1,000. On the basis of five groups of consumers regarding involvement in the event, authors examined brand recognition, using Top of Mind Awareness (TOMA tests of official sponsors and ambushers.

  7. Conformational Smear Characterization and Binning of Single-Molecule Conductance Measurements for Enhanced Molecular Recognition.

    Science.gov (United States)

    Korshoj, Lee E; Afsari, Sepideh; Chatterjee, Anushree; Nagpal, Prashant

    2017-11-01

    Electronic conduction or charge transport through single molecules depends primarily on molecular structure and anchoring groups and forms the basis for a wide range of studies from molecular electronics to DNA sequencing. Several high-throughput nanoelectronic methods such as mechanical break junctions, nanopores, conductive atomic force microscopy, scanning tunneling break junctions, and static nanoscale electrodes are often used for measuring single-molecule conductance. In these measurements, "smearing" due to conformational changes and other entropic factors leads to large variances in the observed molecular conductance, especially in individual measurements. Here, we show a method for characterizing smear in single-molecule conductance measurements and demonstrate how binning measurements according to smear can significantly enhance the use of individual conductance measurements for molecular recognition. Using quantum point contact measurements on single nucleotides within DNA macromolecules, we demonstrate that the distance over which molecular junctions are maintained is a measure of smear, and the resulting variance in unbiased single measurements depends on this smear parameter. Our ability to identify individual DNA nucleotides at 20× coverage increases from 81.3% accuracy without smear analysis to 93.9% with smear characterization and binning (SCRIB). Furthermore, merely 7 conductance measurements (7× coverage) are needed to achieve 97.8% accuracy for DNA nucleotide recognition when only low molecular smear measurements are used, which represents a significant improvement over contemporary sequencing methods. These results have important implications in a broad range of molecular electronics applications from designing robust molecular switches to nanoelectronic DNA sequencing.

  8. An acidic microenvironment sets the humoral pattern recognition molecule PTX3 in a tissue repair mode

    Science.gov (United States)

    Doni, Andrea; Musso, Tiziana; Morone, Diego; Bastone, Antonio; Zambelli, Vanessa; Sironi, Marina; Castagnoli, Carlotta; Cambieri, Irene; Stravalaci, Matteo; Pasqualini, Fabio; Laface, Ilaria; Valentino, Sonia; Tartari, Silvia; Ponzetta, Andrea; Maina, Virginia; Barbieri, Silvia S.; Tremoli, Elena; Catapano, Alberico L.; Norata, Giuseppe D.; Bottazzi, Barbara; Garlanda, Cecilia

    2015-01-01

    Pentraxin 3 (PTX3) is a fluid-phase pattern recognition molecule and a key component of the humoral arm of innate immunity. In four different models of tissue damage in mice, PTX3 deficiency was associated with increased fibrin deposition and persistence, and thicker clots, followed by increased collagen deposition, when compared with controls. Ptx3-deficient macrophages showed defective pericellular fibrinolysis in vitro. PTX3-bound fibrinogen/fibrin and plasminogen at acidic pH and increased plasmin-mediated fibrinolysis. The second exon-encoded N-terminal domain of PTX3 recapitulated the activity of the intact molecule. Thus, a prototypic component of humoral innate immunity, PTX3, plays a nonredundant role in the orchestration of tissue repair and remodeling. Tissue acidification resulting from metabolic adaptation during tissue repair sets PTX3 in a tissue remodeling and repair mode, suggesting that matrix and microbial recognition are common, ancestral features of the humoral arm of innate immunity. PMID:25964372

  9. The pattern recognition molecule ficolin-1 exhibits differential binding to lymphocyte subsets, providing a novel link between innate and adaptive immunity

    DEFF Research Database (Denmark)

    Genster, Ninette; Ma, Ying Jie; Munthe-Fog, Lea

    2014-01-01

    is unknown. Recognition of healthy host cells by a pattern recognition molecule constitutes a potential hazard to self cells and tissues, emphasizing the importance of further elucidating the reported self-recognition. In the current study we investigated the potential recognition of lymphocytes by ficolin-1...... and demonstrated that CD56(dim) NK-cells and both CD4(+) and CD8(+) subsets of activated T-cells were recognized by ficolin-1. In contrast we did not detect binding of ficolin-1 to CD56(bright) NK-cells, NKT-cells, resting T-cells or B-cells. Furthermore, we showed that the protein-lymphocyte interaction occurred...

  10. Function and Dynamics of Tetraspanins during Antigen Recognition and Immunological Synapse Formation

    Directory of Open Access Journals (Sweden)

    Vera eRocha-Perugini

    2016-01-01

    Full Text Available Tetraspanin-enriched microdomains (TEMs are specialized membrane platforms driven by protein-protein interactions that integrate membrane receptors and adhesion molecules. Tetraspanins participate in antigen recognition and presentation by antigen presenting cells (APCs through the organization of pattern recognition receptors (PRRs and their downstream induced-signaling, as well as the regulation of MHC-II-peptide trafficking. T lymphocyte activation is triggered upon specific recognition of antigens present on the APC surface during immunological synapse (IS formation. This dynamic process is characterized by a defined spatial organization involving the compartmentalization of receptors and adhesion molecules in specialized membrane domains that are connected to the underlying cytoskeleton and signaling molecules. Tetraspanins contribute to the spatial organization and maturation of the IS by controlling receptor clustering and local accumulation of adhesion receptors and integrins, their downstream signaling and linkage to the actin cytoskeleton. This review offers a perspective on the important role of TEMs in the regulation of antigen recognition and presentation, and in the dynamics of IS architectural organization.

  11. Function and Dynamics of Tetraspanins during Antigen Recognition and Immunological Synapse Formation

    Science.gov (United States)

    Rocha-Perugini, Vera; Sánchez-Madrid, Francisco; Martínez del Hoyo, Gloria

    2016-01-01

    Tetraspanin-enriched microdomains (TEMs) are specialized membrane platforms driven by protein–protein interactions that integrate membrane receptors and adhesion molecules. Tetraspanins participate in antigen recognition and presentation by antigen-­presenting cells (APCs) through the organization of pattern-recognition receptors (PRRs) and their downstream-induced signaling, as well as the regulation of MHC-II–peptide trafficking. T lymphocyte activation is triggered upon specific recognition of antigens present on the APC surface during immunological synapse (IS) formation. This dynamic process is characterized by a defined spatial organization involving the compartmentalization of receptors and adhesion molecules in specialized membrane domains that are connected to the underlying cytoskeleton and signaling molecules. Tetraspanins contribute to the spatial organization and maturation of the IS by controlling receptor clustering and local accumulation of adhesion receptors and integrins, their downstream signaling, and linkage to the actin cytoskeleton. This review offers a perspective on the important role of TEMs in the regulation of antigen recognition and presentation and in the dynamics of IS architectural organization. PMID:26793193

  12. The innate pattern recognition molecule Ficolin-1 is secreted by monocytes/macrophages and is circulating in human plasma

    DEFF Research Database (Denmark)

    Honoré, Christian; Rørvig, Sara; Munthe-Fog, Lea

    2008-01-01

    Ficolin-1 (M-Ficolin) is a pattern recognition molecule of the complement system that is expressed by myeloid cells and type II alveolar epithelial cells. Ficolin-1 has been shown to localize in the secretory granules of these cells and attached to cell surfaces, but whether Ficolin-1 exists...

  13. The Consolidation of Object and Context Recognition Memory Involve Different Regions of the Temporal Lobe

    Science.gov (United States)

    Balderas, Israela; Rodriguez-Ortiz, Carlos J.; Salgado-Tonda, Paloma; Chavez-Hurtado, Julio; McGaugh, James L.; Bermudez-Rattoni, Federico

    2008-01-01

    These experiments investigated the involvement of several temporal lobe regions in consolidation of recognition memory. Anisomycin, a protein synthesis inhibitor, was infused into the hippocampus, perirhinal cortex, insular cortex, or basolateral amygdala of rats immediately after the sample phase of object or object-in-context recognition memory…

  14. The pattern recognition molecule deleted in malignant brain tumors 1 (DMBT1) and synthetic mimics inhibit liposomal nucleic acid delivery

    DEFF Research Database (Denmark)

    Lund Hansen, Pernille; Blaich, Stephanie; End, Caroline

    2011-01-01

    Liposomal nucleic acid delivery is a preferred option for therapeutic settings. The cellular pattern recognition molecule DMBT1, secreted at high levels in various diseases, and synthetic mimics efficiently inhibit liposomal nucleic acid delivery to human cells. These findings may have relevance...

  15. Accessing Specific Peptide Recognition by Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Li, Ming

    Molecular recognition is at the basis of all processes for life, and plays a central role in many biological processes, such as protein folding, the structural organization of cells and organelles, signal transduction, and the immune response. Hence, my PhD project is entitled “Accessing Specific...... Peptide Recognition by Combinatorial Chemistry”. Molecular recognition is a specific interaction between two or more molecules through noncovalent bonding, such as hydrogen bonding, metal coordination, van der Waals forces, π−π, hydrophobic, or electrostatic interactions. The association involves kinetic....... Combinatorial chemistry was invented in 1980s based on observation of functional aspects of the adaptive immune system. It was employed for drug development and optimization in conjunction with high-throughput synthesis and screening. (chapter 2) Combinatorial chemistry is able to rapidly produce many thousands...

  16. Motor cortical processing is causally involved in object recognition.

    Science.gov (United States)

    Decloe, Rebecca; Obhi, Sukhvinder S

    2013-12-14

    Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action.

  17. Organic Zeolite Analogues Based on Multi-Component Liquid Crystals: Recognition and Transformation of Molecules within Constrained Environments

    Directory of Open Access Journals (Sweden)

    Yasuhiro Ishida

    2011-01-01

    Full Text Available In liquid crystals (LCs, molecules are confined in peculiar environments, where ordered alignment and certain mobility are realized at the same time. Considering these characteristics, the idea of “controlling molecular events within LC media” seems reasonable. As a suitable system for investigating this challenge, we have recently developed a new class of ionic LCs; the salts of amphiphilic carboxylic acids with 2-amino alcohols, or those of carboxylic acids with amphiphilic 2-amino alcohols, have a strong tendency to exhibit thermotropic LC phases. Because of the noncovalent nature of the interaction between molecules, one of the two components can easily be exchanged with, or transformed into, another molecule, without distorting the original LC architecture. In addition, both components are common organic molecules, and a variety of compounds are easily available. Taking advantage of these characteristics, we have succeeded in applying two‑component LCs as chiral media for molecular recognition and reactions. This review presents an overview of our recent studies, together with notable reports related to this field.

  18. Soluble Collectin-12 (CL-12) Is a Pattern Recognition Molecule Initiating Complement Activation via the Alternative Pathway

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Hein, Estrid; Munthe-Fog, Lea

    2015-01-01

    and may recognize certain bacteria and fungi, leading to opsonophagocytosis. However, based on its structural and functional similarities with soluble collectins, we hypothesized the existence of a fluid-phase analog of CL-12 released from cells, which may function as a soluble pattern-recognition...... of the terminal complement complex. These results demonstrate the existence of CL-12 in a soluble form and indicate a novel mechanism by which the alternative pathway of complement may be triggered directly by a soluble pattern-recognition molecule....... nonreducing conditions it presented multimeric assembly forms. Immunoprecipitation and Western blot analysis of human umbilical cord plasma enabled identification of a natural soluble form of CL-12 having an electrophoretic mobility pattern close to that of shed soluble recombinant CL-12. Soluble CL-12 could...

  19. Motor cortical processing is causally involved in object recognition

    Science.gov (United States)

    2013-01-01

    Background Motor activity during vicarious experience of actions is a widely reported and studied phenomenon, and motor system activity also accompanies observation of graspable objects in the absence of any actions. Such motor activity is thought to reflect simulation of the observed action, or preparation to interact with the object, respectively. Results Here, in an initial exploratory study, we ask whether motor activity during observation of object directed actions is involved in processes related to recognition of the object after initial exposure. Single pulse Transcranial Magnetic Stimulation (TMS) was applied over the thumb representation of the motor cortex, or over the vertex, during observation of a model thumb typing on a cell-phone, and performance on a phone recognition task at the end of the trial was assessed. Disrupting motor processing over the thumb representation 100 ms after the onset of the typing video impaired the ability to recognize the phone in the recognition test, whereas there was no such effect for TMS applied over the vertex and no TMS trials. Furthermore, this effect only manifested for videos observed from the first person perspective. In an additional control condition, there was no evidence for any effects of TMS to the thumb representation or vertex when observing and recognizing non-action related shape stimuli. Conclusion Overall, these data provide evidence that motor cortical processing during observation of object-directed actions from a first person perspective is causally linked to the formation of enduring representations of objects-of-action. PMID:24330638

  20. Computer system for structure recognition of polyatomic molecules by i. r. , n. m. r. , u. v. and m. s. methods

    Energy Technology Data Exchange (ETDEWEB)

    Gribov, L A; Elyashberg, M E; Serov, V V [USSR Academy of Sciences, Moscow (USSR). V.I. Vernadsky Institute of Geochemistry and Analytical Chemistry

    1977-12-15

    A system of algorithms and programs for the recognition of the structures of polyatomic molecules by means of i.r., n.m.r., u.v. and mass spectra is described. Examples of structures identified are cited. The results are promising and suggest that the system could be used for the identification of complex organic compounds.

  1. When is the hippocampus involved in recognition memory?

    OpenAIRE

    Barker, Gareth R. I.; Warburton, Elizabeth C.

    2011-01-01

    The role of the hippocampus in recognition memory is controversial. Recognition memory judgments may be made using different types of information, including object familiarity, an object's spatial location, or when an object was encountered. Experiment 1 examined the role of the hippocampus in recognition memory tasks that required the animals to use these different types of mnemonic information. Rats with bilateral cytotoxic lesions in the hippocampus or perirhinal or prefrontal cortex were ...

  2. Collision data involving hydro-carbon molecules

    International Nuclear Information System (INIS)

    Tawara, H.; Itikawa, Y.; Nishimura, H.; Tanaka, H.; Nakamura, Y.

    1990-07-01

    Hydro-carbon molecules are abundantly produced when graphites are used as internal wall materials of hydrogen plasmas and strongly influence properties of low temperature plasmas near the edges as well as those of high temperature plasmas at the center. In this report, following simple description of the production mechanisms of hydro-carbon molecules under the interactions between graphite and hydrogen plasma, the present status of collision data for hydro-carbon molecules by electron impact is discussed and the relevant data are summarized in a series of figures and tables. It should also be noted that, in addition to fusion plasmas, these hydrocarbon data compiled here are quite useful in other applications such as plasma chemistry and material processing. (author)

  3. The influence of propofol anesthesia exposure on nonaversive memory retrieval and expression of molecules involved in memory process in the dorsal hippocampus in peripubertal rats.

    Science.gov (United States)

    Pavković, Željko; Milanović, Desanka; Ruždijić, Sabera; Kanazir, Selma; Pešić, Vesna

    2018-06-01

    The effects of anesthetic drugs on postoperative cognitive function in children are not well defined and have not been experimentally addressed. The present study aimed to examine the influence of propofol anesthesia exposure on nonaversive hippocampus-dependent learning and biochemical changes involved in memory process in the dorsal hippocampus, in peripubertal rats as the rodent model of periadolescence. The intersession spatial habituation and the novel object recognition tasks were used to assess spatial and nonspatial, nonaversive hippocampus-dependent learning. The exposure to anesthesia was performed after comparably long acquisition phases in both tasks. Behavioral testing lasted for 2 consecutive days (24-hour retention period). Changes in the expression of molecules involved in memory retrieval/reconsolidation were examined in the dorsal hippocampus by Western blot and immunohistochemistry, at the time of behavioral testing. Exposure to propofol anesthesia resulted in inappropriate assessment of spatial novelty at the beginning of the test session and affected continuation of acquisition in the spatial habituation test. The treatment did not affect recognition of the novel object at the beginning of the test session but it attenuated overall preference to novelty, reflecting retrieval of a weak memory. The expression of phosphorylated extracellular signal-regulated kinase 2 (involved in memory retrieval) was decreased while the level of phosphorylated Ca 2+ /calmodulin-dependent protein kinase IIα and early growth response protein 1 (involved in memory reconsolidation) was increased in the dorsal hippocampus. The level of Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog B (neuronal activity indicator) was increased in the dorsal dentate gyrus. Enhanced exploratory activity was still evident in the propofol anesthesia exposure (PAE) group 48 hour after the treatment in both tasks. In peripubertal rats, propofol anesthesia exposure

  4. Crystal structures of barley thioredoxin h isoforms HvTrxh1 and HvTrxh2 reveal features involved in protein recognition and possibly in discriminating the isoform specificity

    DEFF Research Database (Denmark)

    Maeda, Kenji; Hägglund, Per; Finnie, Christine

    2008-01-01

    segment of one HvTrxh1 molecule is positioned along a shallow hydrophobic groove at the primary nucleophile Cys40 of another HvTrxh1 molecule. The association mode can serve as a model for the target protein recognition by Trx, as it brings the Met82 C gamma atom (gamma position as a disulfide sulfur......) of the bound loop segment in the proximity of the Cys40 thiol. The interaction involves three characteristic backbone-backbone hydrogen bonds in an antiparallel beta-sheet-like arrangement, similar to the arrangement observed in the structure of an engineered, covalently bound complex between Trx...... and a substrate protein, as reported by Maeda et al. in an earlier paper. The occurrence of an intermolecular salt bridge between Glu80 of the bound loop segment and Arg101 near the hydrophobic groove suggests that charge complementarity plays a role in the specificity of Trx. In HvTrxh2, isoleucine corresponds...

  5. π-Cation Interactions in Molecular Recognition: Perspectives on Pharmaceuticals and Pesticides.

    Science.gov (United States)

    Liang, Zhibin; Li, Qing X

    2018-04-04

    The π-cation interaction that differs from the cation-π interaction is a valuable concept in molecular design of pharmaceuticals and pesticides. In this Perspective we present an up-to-date review (from 1995 to 2017) on bioactive molecules involving π-cation interactions with the recognition site, and categorize into systems of inhibitor-enzyme, ligand-receptor, ligand-transporter, and hapten-antibody. The concept of π-cation interactions offers use of π systems in a small molecule to enhance the binding affinity, specificity, selectivity, lipophilicity, bioavailability, and metabolic stability, which are physiochemical features desired for drugs and pesticides.

  6. Molecular Recognition Involving Anthraquinone Derivatives and Molecular Clips

    Science.gov (United States)

    Alaparthi, Madhubabu

    In the past, we have demonstrated that 1,8-anthraquinone-18-crown-5 (1) and its heterocyclic derivatives act as luminescent hosts for a variety of cations of environmental and clinical concern. We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene - 9,10-dione in a 1:1 ratio (2,3, and 6). These sensors bind metal ions in a 1:1 ratio (7 and 8), and the optical properties of the new complexes were examined and the sulfur and selenium analogues show that selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was competitive for Ca(II) ion. Selective reduction of 1 yields secondary alcohols where either one or both of the anthraquinone carbonyl groups has been reduced ( 15 and 9). A new mechanism for the fluorescence detection of metal cations in solution is introduced involving a unique keto-enol tautomerization. Reduction of 1 yields the doubly reduced secondary alcohol, 9. 9 acts as a chemodosimeter for Al(III) ion producing a strong blue emission due to the formation of the anthracene fluorophore, 10, via dehydration of the internal secondary alcohol in DMSO/aqueous solution. The enol form is not the most thermodynamically stable form under these conditions however, and slowly converts to the keto form 11.. Currently we are focusing on cucurbituril derivatives, also described as molecular clips due to their folded geometry used as molecular recognition hosts. We first investigated the synthesis and characterization of aromatic methoxy/catechol terminated cucurbituril units that act as hosts for small solvent molecules, such as CH2Cl2, CH3CN, DMF, and MeOH, through dual pi...H-C T

  7. Cerebellar involvement in metabolic disorders: a pattern-recognition approach

    International Nuclear Information System (INIS)

    Steinlin, M.; Boltshauser, E.; Blaser, S.

    1998-01-01

    Inborn errors of metabolism can affect the cerebellum during development, maturation and later during life. We have established criteria for pattern recognition of cerebellar abnormalities in metabolic disorders. The abnormalities can be divided into four major groups: cerebellar hypoplasia (CH), hyperplasia, cerebellar atrophy (CA), cerebellar white matter abnormalities (WMA) or swelling, and involvement of the dentate nuclei (DN) or cerebellar cortex. CH can be an isolated typical finding, as in adenylsuccinase deficiency, but is also occasionally seen in many other disorders. Differentiation from CH and CA is often difficult, as in carbohydrate deficient glycoprotein syndrome or 2-l-hydroxyglutaric acidaemia. In cases of atrophy the relationship of cerebellar to cerebral atrophy is important. WMA may be diffuse or patchy, frequently predominantly around the DN. Severe swelling of white matter is present during metabolic crisis in maple syrup urine disease. The DN can be affected by metabolite deposition, necrosis, calcification or demyelination. Involvement of cerebellar cortex is seen in infantile neuroaxonal dystrophy. Changes in DN and cerebellar cortex are rather typical and therefore most helpful; additional features should be sought as they are useful in narrowing down the differential diagnosis. (orig.)

  8. Radically enhanced molecular recognition

    KAUST Repository

    Trabolsi, Ali

    2009-12-17

    The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

  9. Radically enhanced molecular recognition

    KAUST Repository

    Trabolsi, Ali; Khashab, Niveen M.; Fahrenbach, Albert C.; Friedman, Douglas C.; Colvin, Michael T.; Coti, Karla K.; Bení tez, Diego S.; Tkatchouk, Ekaterina; Olsen, John Carl; Belowich, Matthew E.; Carmieli, Raanan; Khatib, Hussam A.; Goddard, William Andrew III; Wasielewski, Michael R.; Stoddart, Fraser Fraser Raser

    2009-01-01

    The tendency for viologen radical cations to dimerize has been harnessed to establish a recognition motif based on their ability to form extremely strong inclusion complexes with cyclobis(paraquat-p-phenylene) in its diradical dicationic redox state. This previously unreported complex involving three bipyridinium cation radicals increases the versatility of host-guest chemistry, extending its practice beyond the traditional reliance on neutral and charged guests and hosts. In particular, transporting the concept of radical dimerization into the field of mechanically interlocked molecules introduces a higher level of control within molecular switches and machines. Herein, we report that bistable and tristable [2]rotaxanes can be switched by altering electrochemical potentials. In a tristable [2]rotaxane composed of a cyclobis(paraquat-p-phenylene) ring and a dumbbell with tetrathiafulvalene, dioxynaphthalene and bipyridinium recognition sites, the position of the ring can be switched. On oxidation, it moves from the tetrathiafulvalene to the dioxynaphthalene, and on reduction, to the bipyridinium radical cation, provided the ring is also reduced simultaneously to the diradical dication. © 2010 Macmillan Publishers Limited. All rights reserved.

  10. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ying [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Huang, Xiaohua [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Clinical Biochemistry, College of Laboratory Medicine, Dalian Medical University, Dalian 116044 (China); An, Yue [Department of Clinical Laboratory, Second Affiliated Hospital of Dalian Medical University, Dalian 116023 (China); Ren, Feng [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); He, Xiaowen; Schachner, Melitta [Keck Center for Collaborative Neuroscience and Department of Cell Biology and Neuroscience, Rutgers University, New Brunswick, NJ (United States); Xiao, Zhicheng, E-mail: zhicheng.xiao@monash.edu [The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming 650228 (China); Department of Anatomy and Developmental Biology, Monash University, Clayton 3800 (Australia); Ma, Keli, E-mail: makeli666@aliyun.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Li, Yali, E-mail: yalilipaper@gmail.com [Department of Biochemistry and Molecular Biology, Dalian Medical University, Dalian 116044 (China); Department of Anatomy, National University of Singapore, Singapore 119078 (Singapore)

    2013-10-25

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression.

  11. Cell recognition molecule L1 promotes embryonic stem cell differentiation through the regulation of cell surface glycosylation

    International Nuclear Information System (INIS)

    Li, Ying; Huang, Xiaohua; An, Yue; Ren, Feng; Yang, Zara Zhuyun; Zhu, Hongmei; Zhou, Lei; He, Xiaowen; Schachner, Melitta; Xiao, Zhicheng; Ma, Keli; Li, Yali

    2013-01-01

    Highlights: •Down-regulating FUT9 and ST3Gal4 expression blocks L1-induced neuronal differentiation of ESCs. •Up-regulating FUT9 and ST3Gal4 expression in L1-ESCs depends on the activation of PLCγ. •L1 promotes ESCs to differentiate into neuron through regulating cell surface glycosylation. -- Abstract: Cell recognition molecule L1 (CD171) plays an important role in neuronal survival, migration, differentiation, neurite outgrowth, myelination, synaptic plasticity and regeneration after injury. Our previous study has demonstrated that overexpressing L1 enhances cell survival and proliferation of mouse embryonic stem cells (ESCs) through promoting the expression of FUT9 and ST3Gal4, which upregulates cell surface sialylation and fucosylation. In the present study, we examined whether sialylation and fucosylation are involved in ESC differentiation through L1 signaling. RNA interference analysis showed that L1 enhanced differentiation of ESCs into neurons through the upregulation of FUT9 and ST3Gal4. Furthermore, blocking the phospholipase Cγ (PLCγ) signaling pathway with either a specific PLCγ inhibitor or knockdown PLCγ reduced the expression levels of both FUT9 and ST3Gal4 mRNAs and inhibited L1-mediated neuronal differentiation. These results demonstrate that L1 promotes neuronal differentiation from ESCs through the L1-mediated enhancement of FUT9 and ST3Gal4 expression

  12. Point-of-Care Determination of Acetaminophen Levels with Multi-Hydrogen Bond Manipulated Single-Molecule Recognition (eMuHSiR).

    Science.gov (United States)

    Zhang, Yan; Huang, Zhongyuan; Wang, Letao; Wang, Chunming; Zhang, Changde; Wiese, Tomas; Wang, Guangdi; Riley, Kevin; Wang, Zhe

    2018-04-03

    This work aims to face the challenge of monitoring small molecule drugs accurately and rapidly for point-of-care (POC) diagnosis in current clinical settings. Overdose of acetaminophen (AP), a commonly used over the counter (OTC) analgesic drug, has been determined to be a major cause of acute liver failure in the US and the UK. However, there is no rapid and accurate detection method available for this drug in the emergency room. The present study examined an AP sensing strategy that relies on a previously unexplored strong interaction between AP and the arginine (Arg) molecule. It was found that as many as 4 hydrogen bonds can be formed between one Arg molecule and one AP molecule. By taking advantages of this structural selectivity and high tenability of hydrogen bonds, Arg, immobilized on a graphene surface via electrostatic interactions, was utilized to structurally capture AP. Interestingly, bonded AP still remained the perfect electrochemical activities. The extent of Arg-AP bonds was quantified using a newly designed electrochemical (EC) sensor. To verify the feasibility of this novel assay, based on multihydrogen bond manipulated single-molecule recognition (eMuHSiR), both pharmaceutical and serum sample were examined. In commercial tablet measurement, no significant difference was seen between the results of eMuHSiR and other standard methods. For measuring AP concentration in the mice blood, the substances in serum, such as sugars and fats, would not bring any interference to the eMuHSiR in a wide concentration range. This eMuHSiR method opens the way for future development of small molecule detection for the POC testing.

  13. PTX3, a Humoral Pattern Recognition Molecule, in Innate Immunity, Tissue Repair, and Cancer.

    Science.gov (United States)

    Garlanda, Cecilia; Bottazzi, Barbara; Magrini, Elena; Inforzato, Antonio; Mantovani, Alberto

    2018-04-01

    Innate immunity includes a cellular and a humoral arm. PTX3 is a fluid-phase pattern recognition molecule conserved in evolution which acts as a key component of humoral innate immunity in infections of fungal, bacterial, and viral origin. PTX3 binds conserved microbial structures and self-components under conditions of inflammation and activates effector functions (complement, phagocytosis). Moreover, it has a complex regulatory role in inflammation, such as ischemia/reperfusion injury and cancer-related inflammation, as well as in extracellular matrix organization and remodeling, with profound implications in physiology and pathology. Finally, PTX3 acts as an extrinsic oncosuppressor gene by taming tumor-promoting inflammation in murine and selected human tumors. Thus evidence suggests that PTX3 is a key homeostatic component at the crossroad of innate immunity, inflammation, tissue repair, and cancer. Dissecting the complexity of PTX3 pathophysiology and human genetics paves the way to diagnostic and therapeutic exploitation.

  14. Bio-recognitive photonics of a DNA-guided organic semiconductor

    Science.gov (United States)

    Back, Seung Hyuk; Park, Jin Hyuk; Cui, Chunzhi; Ahn, Dong June

    2016-01-01

    Incorporation of duplex DNA with higher molecular weights has attracted attention for a new opportunity towards a better organic light-emitting diode (OLED) capability. However, biological recognition by OLED materials is yet to be addressed. In this study, specific oligomeric DNA-DNA recognition is successfully achieved by tri (8-hydroxyquinoline) aluminium (Alq3), an organic semiconductor. Alq3 rods crystallized with guidance from single-strand DNA molecules show, strikingly, a unique distribution of the DNA molecules with a shape of an `inverted' hourglass. The crystal's luminescent intensity is enhanced by 1.6-fold upon recognition of the perfect-matched target DNA sequence, but not in the case of a single-base mismatched one. The DNA-DNA recognition forming double-helix structure is identified to occur only in the rod's outer periphery. This study opens up new opportunities of Alq3, one of the most widely used OLED materials, enabling biological recognition.

  15. Bio-recognitive photonics of a DNA-guided organic semiconductor.

    Science.gov (United States)

    Back, Seung Hyuk; Park, Jin Hyuk; Cui, Chunzhi; Ahn, Dong June

    2016-01-04

    Incorporation of duplex DNA with higher molecular weights has attracted attention for a new opportunity towards a better organic light-emitting diode (OLED) capability. However, biological recognition by OLED materials is yet to be addressed. In this study, specific oligomeric DNA-DNA recognition is successfully achieved by tri (8-hydroxyquinoline) aluminium (Alq3), an organic semiconductor. Alq3 rods crystallized with guidance from single-strand DNA molecules show, strikingly, a unique distribution of the DNA molecules with a shape of an 'inverted' hourglass. The crystal's luminescent intensity is enhanced by 1.6-fold upon recognition of the perfect-matched target DNA sequence, but not in the case of a single-base mismatched one. The DNA-DNA recognition forming double-helix structure is identified to occur only in the rod's outer periphery. This study opens up new opportunities of Alq3, one of the most widely used OLED materials, enabling biological recognition.

  16. 77 FR 54584 - Final Action Under the NIH Guidelines for Research Involving Recombinant DNA Molecules (NIH...

    Science.gov (United States)

    2012-09-05

    ... changes. Human gene transfer also raises scientific, medical, social, and ethical considerations that... currently reviewed under Section III-B-1, Experiments Involving the Cloning of Toxin Molecules with LD50 of...

  17. Acoustic input and efferent activity regulate the expression of molecules involved in cochlear micromechanics

    Science.gov (United States)

    Lamas, Veronica; Arévalo, Juan C.; Juiz, José M.; Merchán, Miguel A.

    2015-01-01

    Electromotile activity in auditory outer hair cells (OHCs) is essential for sound amplification. It relies on the highly specialized membrane motor protein prestin, and its interactions with the cytoskeleton. It is believed that the expression of prestin and related molecules involved in OHC electromotility may be dynamically regulated by signals from the acoustic environment. However little is known about the nature of such signals and how they affect the expression of molecules involved in electromotility in OHCs. We show evidence that prestin oligomerization is regulated, both at short and relatively long term, by acoustic input and descending efferent activity originating in the cortex, likely acting in concert. Unilateral removal of the middle ear ossicular chain reduces levels of trimeric prestin, particularly in the cochlea from the side of the lesion, whereas monomeric and dimeric forms are maintained or even increased in particular in the contralateral side, as shown in Western blots. Unilateral removal of the auditory cortex (AC), which likely causes an imbalance in descending efferent activity on the cochlea, also reduces levels of trimeric and tetrameric forms of prestin in the side ipsilateral to the lesion, whereas in the contralateral side prestin remains unaffected, or even increased in the case of trimeric and tetrameric forms. As far as efferent inputs are concerned, unilateral ablation of the AC up-regulates the expression of α10 nicotinic Ach receptor (nAChR) transcripts in the cochlea, as shown by RT-Quantitative real-time PCR (qPCR). This suggests that homeostatic synaptic scaling mechanisms may be involved in dynamically regulating OHC electromotility by medial olivocochlear efferents. Limited, unbalanced efferent activity after unilateral AC removal, also affects prestin and β-actin mRNA levels. These findings support that the concerted action of acoustic and efferent inputs to the cochlea is needed to regulate the expression of major

  18. Preparation and Property Recognition of Nimodipine Molecularly Imprinted Polymer

    Directory of Open Access Journals (Sweden)

    Fei-fei CHEN

    2015-09-01

    Full Text Available Objective: To explore the application of molecular imprinting technique in the separation and detection of nimodipine. Methods: Methacrylic acid as functional monomer, pentaerythritol triacrylate as cross-linking agent were used to prepare molecularly imprinted polymer (MIP with the feature of specific recognition performance on imprinting molecule nimodipine under condition of template molecule nimodipine. The preparation conditions, recognition performance of MIP on nimodipine, different proportions of template molecule and functional monomer, the selectivity to other substrate, and the relationship between adsorption quantity (Q and time were observed. Results: MIP was prepared successfully bynimodipine as template and pentaerythritol triacrylate as cross-linking agent, with the feature of specific recognition performance on nimodipine. The static adsorption distribution coefficient (KD was 0.2264. The equation of Q and the concentration of substrate of template MIP was y = -0.21x+0.2204. Combining capacity of template molecule at the same concentration enhanced with the increasing proportion of functional monomer.Conclusion: Nimodipine MIP based on molecular imprinting technique may become a new approach to chiral separation for nimodipine.

  19. What Are the Molecules Involved in Regulatory T-Cells Induction by Dendritic Cells in Cancer?

    Directory of Open Access Journals (Sweden)

    Rodrigo Nalio Ramos

    2013-01-01

    Full Text Available Dendritic cells (DCs are essential for the maintenance of homeostasis in the organism, and they do that by modulating lymphocyte priming, expansion, and response patterns according to signals they receive from the environment. The induction of suppressive lymphocytes by DCs is essential to hinder the development of autoimmune diseases but can be reverted against homeostasis when in the context of neoplasia. In this setting, the induction of suppressive or regulatory T cells contributes to the establishment of a state of tolerance towards the tumor, allowing it to grow unchecked by an otherwise functional immune system. Besides affecting its local environment, tumor also has been described as potent sources of anti-inflammatory/suppressive factors, which may act systemically, generating defects in the differentiation and maturation of immune cells, far beyond the immediate vicinity of the tumor mass. Cytokines, as IL-10 and TGF-beta, as well as cell surface molecules like PD-L1 and ICOS seem to be significantly involved in the redirection of DCs towards tolerance induction, and recent data suggest that tumor cells may, indeed, modulate distinct DCs subpopulations through the involvement of these molecules. It is to be expected that the identification of such molecules should provide molecular targets for more effective immunotherapeutic approaches to cancer.

  20. Hemispheric lateralization of linguistic prosody recognition in comparison to speech and speaker recognition.

    Science.gov (United States)

    Kreitewolf, Jens; Friederici, Angela D; von Kriegstein, Katharina

    2014-11-15

    Hemispheric specialization for linguistic prosody is a controversial issue. While it is commonly assumed that linguistic prosody and emotional prosody are preferentially processed in the right hemisphere, neuropsychological work directly comparing processes of linguistic prosody and emotional prosody suggests a predominant role of the left hemisphere for linguistic prosody processing. Here, we used two functional magnetic resonance imaging (fMRI) experiments to clarify the role of left and right hemispheres in the neural processing of linguistic prosody. In the first experiment, we sought to confirm previous findings showing that linguistic prosody processing compared to other speech-related processes predominantly involves the right hemisphere. Unlike previous studies, we controlled for stimulus influences by employing a prosody and speech task using the same speech material. The second experiment was designed to investigate whether a left-hemispheric involvement in linguistic prosody processing is specific to contrasts between linguistic prosody and emotional prosody or whether it also occurs when linguistic prosody is contrasted against other non-linguistic processes (i.e., speaker recognition). Prosody and speaker tasks were performed on the same stimulus material. In both experiments, linguistic prosody processing was associated with activity in temporal, frontal, parietal and cerebellar regions. Activation in temporo-frontal regions showed differential lateralization depending on whether the control task required recognition of speech or speaker: recognition of linguistic prosody predominantly involved right temporo-frontal areas when it was contrasted against speech recognition; when contrasted against speaker recognition, recognition of linguistic prosody predominantly involved left temporo-frontal areas. The results show that linguistic prosody processing involves functions of both hemispheres and suggest that recognition of linguistic prosody is based on

  1. The inhibitory NKR-P1B:Clr-b recognition axis facilitates detection of oncogenic transformation and cancer immunosurveillance

    DEFF Research Database (Denmark)

    Tanaka, M; Fine, Jason; Kirkham, Christina

    2018-01-01

    Natural killer (NK) cells express receptors specific for MHC class I (MHC-I) molecules involved in "missing-self" recognition of cancer and virus-infected cells. Here we elucidate the role of MHC-I-independent NKR-P1B:Clr-b interactions in the detection of oncogenic transformation by NK cells. Ras......-b protein, in turn promoting missing-self recognition via the NKR-P1B inhibitory receptor. Both Ras- and c-Myc-mediated Clr-b loss selectively augmented cytotoxicity of oncogene-transformed leukemia cells by NKR-P1B+ NK cells in vitro and enhanced rejection by WT mice in vivo. Interestingly, genetic...

  2. Chloroplastic protein NRIP1 mediates innate immune receptor recognition of a viral effector

    Science.gov (United States)

    Caplan, Jeffrey L.; Mamillapalli, Padmavathi; Burch-Smith, Tessa M.; Czymmek, Kirk; Dinesh-Kumar, S.P.

    2008-01-01

    Summary Plant innate immunity relies on the recognition of pathogen effector molecules by nucleotide-binding-leucine-rich repeat (NB-LRR) immune receptor families. Previously we have shown the N immune receptor, a member of TIR-NB-LRR family, indirectly recognizes the 50-kDa helicase (p50) domain of Tobacco mosaic virus (TMV) through its TIR domain. We have identified an N receptor-interacting protein, NRIP1, that directly interacts with both N's TIR domain and p50. NRIP1 is a functional rhodanese sulfurtransferase and is required for N to provide complete resistance to TMV. Interestingly, NRIP1 that normally localizes to the chloroplasts is recruited to the cytoplasm and nucleus by the p50 effector. As a consequence, NRIP1 interacts with N only in the presence of the p50 effector. Our findings show that a chloroplastic protein is intimately involved in pathogen recognition. We propose that N's activation requires a pre-recognition complex containing the p50 effector and NRIP1. PMID:18267075

  3. Emmprin (basigin/CD147): matrix metalloproteinase modulator and multifunctional cell recognition molecule that plays a critical role in cancer progression.

    Science.gov (United States)

    Nabeshima, Kazuki; Iwasaki, Hiroshi; Koga, Kaori; Hojo, Hironobu; Suzumiya, Junji; Kikuchi, Masahiro

    2006-07-01

    Emmprin (basigin, CD147) is a cell surface glycoprotein that belongs to the immunoglobulin superfamily. It is highly expressed on the surface of tumor cells and stimulates adjacent fibroblasts or tumor cells to produce matrix metalloproteinases. Moreover, it has recently been shown that emmprin also stimulates expression of vascular endothelial growth factor and hyaluronan, which leads to angiogenesis and anchorage-independent growth/multidrug resistance, respectively. These findings have made emmprin an important molecule in tumor progression and, thus, more attractive as a target for antitumor treatment. However, other functions of emmprin, including as an activator of T cells, a chaperone for monocarboxylate transporters, a receptor for cyclophilin A and a neural recognition molecule, are also being identified in physiological and pathological conditions. Therefore, it is essential to develop specific means to control particular functions of emmprin, for which elucidation of each mechanism is crucial. This review will discuss the role of emmprin in tumor progression and recent advances in the molecular mechanisms of diverse phenomena regulated by emmprin.

  4. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Directory of Open Access Journals (Sweden)

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  5. The Swipe Card Model of Odorant Recognition 

    Directory of Open Access Journals (Sweden)

    Jennifer C. Brookes

    2012-11-01

    Full Text Available Just how we discriminate between the different odours we encounter is notcompletely understood yet. While obviously a matter involving biology, the core issue isa matter for physics: what microscopic interactions enable the receptors in our noses-smallprotein switches—to distinguish scent molecules? We survey what is and is not known aboutthe physical processes that take place when we smell things, highlighting the difficultiesin developing a full understanding of the mechanics of odorant recognition. The maincurrent theories, discussed here, fall into two major groups. One class emphasises thescent molecule's shape, and is described informally as a "lock and key" mechanism. Butthere is another category, which we focus on and which we call "swipe card" theories:the molecular shape must be good enough, but the information that identifies the smellinvolves other factors. One clearly-defined "swipe card" mechanism that we discuss hereis Turin's theory, in which inelastic electron tunnelling is used to discern olfactant vibrationfrequencies. This theory is explicitly quantal, since it requires the molecular vibrations totake in or give out energy only in discrete quanta. These ideas lead to obvious experimentaltests and challenges. We describe the current theory in a form that takes into accountmolecular shape as well as olfactant vibrations. It emerges that this theory can explainmany observations hard to reconcile in other ways. There are still some important gapsin a comprehensive physics-based description of the central steps in odorant recognition. We also discuss how far these ideas carry over to analogous processes involving other smallbiomolecules, like hormones, steroids and neurotransmitters. We conclude with a discussionof possible quantum behaviours in biology more generally, the case of olfaction being justone example. This paper is presented in honour of Prof. Marshall Stoneham who passedaway unexpectedly during its writing. 

  6. Nucleic Acid Sensors Involved in the Recognition of HBV in the Liver–Specific in vivo Transfection Mouse Models—Pattern Recognition Receptors and Sensors for HBV

    Directory of Open Access Journals (Sweden)

    Chean Ring Leong

    2015-04-01

    Full Text Available Cellular innate immune system recognizing pathogen infection is critical for the host defense against viruses. Hepatitis B virus (HBV is a DNA virus with a unique life cycle whereby the DNA and RNA intermediates present at different phases. However, it is still unclear whether the viral DNA or RNA templates are recognized by the pattern-recognition receptors (PRRs to trigger host antiviral immune response. Here in this article, we review the recent advances in the progress of the HBV studies, focusing on the nucleic acid sensors and the pathways involved in the recognition of HBV in the liver–specific in vivo transfection mouse models. Hydrodynamic injection transfecting the hepatocytes in the gene-disrupted mouse model with the HBV replicative genome DNA has revealed that IFNAR and IRF3/7 are indispensable in HBV eradication in the mice liver but not the RNA sensing pathways. Interestingly, accumulating evidence of the recent studies has demonstrated that HBV markedly interfered with IFN-β induction and antiviral immunity mediated by the Stimulator of interferon genes (STING, which has been identified as a central factor in foreign DNA recognition and antiviral innate immunity. This review will present the current understanding of innate immunity in HBV infection and of the challenges for clearing of the HBV infection.

  7. Analysis of DNA interactions using single-molecule force spectroscopy.

    Science.gov (United States)

    Ritzefeld, Markus; Walhorn, Volker; Anselmetti, Dario; Sewald, Norbert

    2013-06-01

    Protein-DNA interactions are involved in many biochemical pathways and determine the fate of the corresponding cell. Qualitative and quantitative investigations on these recognition and binding processes are of key importance for an improved understanding of biochemical processes and also for systems biology. This review article focusses on atomic force microscopy (AFM)-based single-molecule force spectroscopy and its application to the quantification of forces and binding mechanisms that lead to the formation of protein-DNA complexes. AFM and dynamic force spectroscopy are exciting tools that allow for quantitative analysis of biomolecular interactions. Besides an overview on the method and the most important immobilization approaches, the physical basics of the data evaluation is described. Recent applications of AFM-based force spectroscopy to investigate DNA intercalation, complexes involving DNA aptamers and peptide- and protein-DNA interactions are given.

  8. [Prosopagnosia and facial expression recognition].

    Science.gov (United States)

    Koyama, Shinichi

    2014-04-01

    This paper reviews clinical neuropsychological studies that have indicated that the recognition of a person's identity and the recognition of facial expressions are processed by different cortical and subcortical areas of the brain. The fusiform gyrus, especially the right fusiform gyrus, plays an important role in the recognition of identity. The superior temporal sulcus, amygdala, and medial frontal cortex play important roles in facial-expression recognition. Both facial recognition and facial-expression recognition are highly intellectual processes that involve several regions of the brain.

  9. Involvement of hippocampal NMDA receptors in retrieval of spontaneous object recognition memory in rats.

    Science.gov (United States)

    Iwamura, Etsushi; Yamada, Kazuo; Ichitani, Yukio

    2016-07-01

    The involvement of hippocampal N-methyl-d-aspartate (NMDA) receptors in the retrieval process of spontaneous object recognition memory was investigated. The spontaneous object recognition test consisted of three phases. In the sample phase, rats were exposed to two identical objects several (2-5) times in the arena. After the sample phase, various lengths of delay intervals (24h-6 weeks) were inserted (delay phase). In the test phase in which both the familiar and the novel objects were placed in the arena, rats' novel object exploration behavior under the hippocampal treatment of NMDA receptor antagonist, AP5, or vehicle was observed. With 5 exposure sessions in the sample phase (experiment 1), AP5 treatment in the test phase significantly decreased discrimination ratio when the delay was 3 weeks but not when it was one week. On the other hand, with 2 exposure sessions in the sample phase (experiment 2) in which even vehicle-injected control animals could not discriminate the novel object from the familiar one with a 3 week delay, AP5 treatment significantly decreased discrimination ratio when the delay was one week, but not when it was 24h. Additional experiment (experiment 3) showed that the hippocampal treatment of an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist, NBQX, decreased discrimination ratio with all delay intervals tested (24h-3 weeks). Results suggest that hippocampal NMDA receptors play an important role in the retrieval of spontaneous object recognition memory especially when the memory trace weakens. Copyright © 2016. Published by Elsevier B.V.

  10. Molecular recognition of chromophore molecules to amine terminated surfaces

    International Nuclear Information System (INIS)

    Flores-Perez, Rosangelly; Ivanisevic, Albena

    2007-01-01

    We report the design and characterization of quartz surfaces that can bind to three retinal based chromophores. The amine terminated surfaces were engineered in order to mimic the environment of the opsin protein that accommodates binding of chromophore molecules in the human eye. Each surface coupling step was characterized by water contact angle measurements, ellipsometry, atomic force microscopy, X-ray photoelectron spectroscopy, and transmission infrared spectroscopy. The spectroscopic techniques confirmed that the three chromophore molecules can bind to the surface using a Schiff base mode. Our data suggests that the availability of the amine groups on the surface is critical in the accommodation of the binding of different chromophores

  11. Hippocampal NMDA receptors are involved in rats' spontaneous object recognition only under high memory load condition.

    Science.gov (United States)

    Sugita, Manami; Yamada, Kazuo; Iguchi, Natsumi; Ichitani, Yukio

    2015-10-22

    The possible involvement of hippocampal N-methyl-D-aspartate (NMDA) receptors in spontaneous object recognition was investigated in rats under different memory load conditions. We first estimated rats' object memory span using 3-5 objects in "Different Objects Task (DOT)" in order to confirm the highest memory load condition in object recognition memory. Rats were allowed to explore a field in which 3 (3-DOT), 4 (4-DOT), or 5 (5-DOT) different objects were presented. After a delay period, they were placed again in the same field in which one of the sample objects was replaced by another object, and their object exploration behavior was analyzed. Rats could differentiate the novel object from the familiar ones in 3-DOT and 4-DOT but not in 5-DOT, suggesting that rats' object memory span was about 4. Then, we examined the effects of hippocampal AP5 infusion on performance in both 2-DOT (2 different objects were used) and 4-DOT. The drug treatment before the sample phase impaired performance only in 4-DOT. These results suggest that hippocampal NMDA receptors play a critical role in spontaneous object recognition only when the memory load is high. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Kernel learning algorithms for face recognition

    CERN Document Server

    Li, Jun-Bao; Pan, Jeng-Shyang

    2013-01-01

    Kernel Learning Algorithms for Face Recognition covers the framework of kernel based face recognition. This book discusses the advanced kernel learning algorithms and its application on face recognition. This book also focuses on the theoretical deviation, the system framework and experiments involving kernel based face recognition. Included within are algorithms of kernel based face recognition, and also the feasibility of the kernel based face recognition method. This book provides researchers in pattern recognition and machine learning area with advanced face recognition methods and its new

  13. Functionalization of Probe Tips and Supports for Single-Molecule Recognition Force Microscopy

    Science.gov (United States)

    Ebner, Andreas; Wildling, Linda; Zhu, Rong; Rankl, Christian; Haselgrübler, Thomas; Hinterdorfer, Peter; Gruber, Hermann J.

    The measuring tip of a force microscope can be converted into a monomolecular sensor if one or few "ligand" molecules are attached to the apex of the tip while maintaining ligand function. Functionalized tips are used to study fine details of receptor-ligand interaction by force spectroscopy or to map cognate "receptor" molecules on the sample surface. The receptor (or target) molecules can be present on the surface of a biological specimen; alternatively, soluble target molecules must be immobilized on ultraflat supports. This review describes the methods of tip functionalization, as well as target molecule immobilization. Silicon nitride tips, silicon chips, and mica have usually been functionalized in three steps: (1) aminofunctionalization, (2) crosslinker attachment, and (3) ligand/receptor coupling, whereby numerous crosslinkers are available to couple widely different ligand molecules. Gold-covered tips and/or supports have usually been coated with a self-assembled monolayer, on top of which the ligand/receptor molecule has been coupled either directly or via a crosslinker molecule. Apart from these general strategies, many simplified methods have been used for tip and/or support functionalization, even single-step methods such as adsorption or chemisorption being very efficient under suitable circumstances. All methods are described with the same explicitness and critical parameters are discussed. In conclusion, this review should help to find suitable methods for specific problems of tip and support functionalization.

  14. Simultaneous topography and recognition imaging: physical aspects and optimal imaging conditions

    International Nuclear Information System (INIS)

    Preiner, Johannes; Ebner, Andreas; Zhu Rong; Hinterdorfer, Peter; Chtcheglova, Lilia

    2009-01-01

    Simultaneous topography and recognition imaging (TREC) allows for the investigation of receptor distributions on natural biological surfaces under physiological conditions. Based on atomic force microscopy (AFM) in combination with a cantilever tip carrying a ligand molecule, it enables us to sense topography and recognition of receptor molecules simultaneously with nanometre accuracy. In this study we introduce optimized handling conditions and investigate the physical properties of the cantilever-tip-sample ensemble, which is essential for the interpretation of the experimental data gained from this technique. In contrast to conventional AFM methods, TREC is based on a more sophisticated feedback loop, which enables us to discriminate topographical contributions from recognition events in the AFM cantilever motion. The features of this feedback loop were investigated through a detailed analysis of the topography and recognition data obtained on a model protein system. Single avidin molecules immobilized on a mica substrate were imaged with an AFM tip functionalized with a biotinylated IgG. A simple procedure for adjusting the optimal amplitude for TREC imaging is described by exploiting the sharp localization of the TREC signal within a small range of oscillation amplitudes. This procedure can also be used for proving the specificity of the detected receptor-ligand interactions. For understanding and eliminating topographical crosstalk in the recognition images we developed a simple theoretical model, which nicely explains its origin and its dependence on the excitation frequency.

  15. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes

    DEFF Research Database (Denmark)

    Pirrotta, Alessandro; De Vico, Luca; Solomon, Gemma C.

    2017-01-01

    to inform about molecular recognition events at the single-molecule limit. For this, we consider the force-conductance characteristics of a prototypical class of hydrogen bonded bimolecular complexes sandwiched between gold electrodes. The complexes consist of derivatives of a barbituric acid and a Hamilton...... is mechanically manipulated. The implication is that force and conductance provide complementary information about the evolution of molecules in junctions that can be used to interrogate basic structure-transport relations at the single-molecule limit....

  16. Glutathione--hydroxyl radical interaction: a theoretical study on radical recognition process.

    Directory of Open Access Journals (Sweden)

    Béla Fiser

    Full Text Available Non-reactive, comparative (2 × 1.2 μs molecular dynamics simulations were carried out to characterize the interactions between glutathione (GSH, host molecule and hydroxyl radical (OH(•, guest molecule. From this analysis, two distinct steps were identified in the recognition process of hydroxyl radical by glutathione: catching and steering, based on the interactions between the host-guest molecules. Over 78% of all interactions are related to the catching mechanism via complex formation between anionic carboxyl groups and the OH radical, hence both terminal residues of GSH serve as recognition sites. The glycine residue has an additional role in the recognition of OH radical, namely the steering. The flexibility of the Gly residue enables the formation of further interactions of other parts of glutathione (e.g. thiol, α- and β-carbons with the lone electron pair of the hydroxyl radical. Moreover, quantum chemical calculations were carried out on selected GSH/OH(• complexes and on appropriate GSH conformers to describe the energy profile of the recognition process. The relative enthalpy and the free energy changes of the radical recognition of the strongest complexes varied from -42.4 to -27.8 kJ/mol and from -21.3 to 9.8 kJ/mol, respectively. These complexes, containing two or more intermolecular interactions, would be the starting configurations for the hydrogen atom migration to quench the hydroxyl radical via different reaction channels.

  17. Development of novel small molecules for imaging and drug release

    Science.gov (United States)

    Cao, Yanting

    Small organic molecules, including small molecule based fluorescent probes, small molecule based drugs or prodrugs, and smart multifunctional fluorescent drug delivery systems play important roles in biological research, drug discovery, and clinical practices. Despite the significant progress made in these fields, the development of novel and diverse small molecules is needed to meet various demands for research and clinical applications. My Ph.D study focuses on the development of novel functional molecules for recognition, imaging and drug release. In the first part, a turn-on fluorescent probe is developed for the detection of intracellular adenosine-5'-triphosphate (ATP) levels based on multiplexing recognitions. Considering the unique and complicated structure of ATP molecules, a fluorescent probe has been implemented with improved sensitivity and selectivity due to two synergistic binding recognitions by incorporating of 2, 2'-dipicolylamine (Dpa)-Zn(II) for targeting of phospho anions and phenylboronic acid group for cis-diol moiety. The novel probe is able to detect intracellular ATP levels in SH-SY5Y cells. Meanwhile, the advantages of multiplexing recognition design concept have been demonstrated using two control molecules. In the second part, a prodrug system is developed to deliver multiple drugs within one small molecule entity. The prodrug is designed by using 1-(2-nitrophenyl)ethyl (NPE) as phototrigger, and biphenol biquaternary ammonium as the prodrug. With controlled photo activation, both DNA cross-linking agents mechlorethamine and o-quinone methide are delivered and released at the preferred site, leading to efficient DNA cross-links formation and cell death. The prodrug shows negligible cytotoxicity towards normal skin cells (Hekn cells) with and without UV activation, but displays potent activity towards cancer cells (HeLa cells) upon UV activation. The multiple drug release system may hold a great potential for practical application. In the

  18. Genetic Mapping in Mice Reveals the Involvement of Pcdh9 in Long-Term Social and Object Recognition and Sensorimotor Development.

    Science.gov (United States)

    Bruining, Hilgo; Matsui, Asuka; Oguro-Ando, Asami; Kahn, René S; Van't Spijker, Heleen M; Akkermans, Guus; Stiedl, Oliver; van Engeland, Herman; Koopmans, Bastijn; van Lith, Hein A; Oppelaar, Hugo; Tieland, Liselotte; Nonkes, Lourens J; Yagi, Takeshi; Kaneko, Ryosuke; Burbach, J Peter H; Yamamoto, Nobuhiko; Kas, Martien J

    2015-10-01

    Quantitative genetic analysis of basic mouse behaviors is a powerful tool to identify novel genetic phenotypes contributing to neurobehavioral disorders. Here, we analyzed genetic contributions to single-trial, long-term social and nonsocial recognition and subsequently studied the functional impact of an identified candidate gene on behavioral development. Genetic mapping of single-trial social recognition was performed in chromosome substitution strains, a sophisticated tool for detecting quantitative trait loci (QTL) of complex traits. Follow-up occurred by generating and testing knockout (KO) mice of a selected QTL candidate gene. Functional characterization of these mice was performed through behavioral and neurological assessments across developmental stages and analyses of gene expression and brain morphology. Chromosome substitution strain 14 mapping studies revealed an overlapping QTL related to long-term social and object recognition harboring Pcdh9, a cell-adhesion gene previously associated with autism spectrum disorder. Specific long-term social and object recognition deficits were confirmed in homozygous (KO) Pcdh9-deficient mice, while heterozygous mice only showed long-term social recognition impairment. The recognition deficits in KO mice were not associated with alterations in perception, multi-trial discrimination learning, sociability, behavioral flexibility, or fear memory. Rather, KO mice showed additional impairments in sensorimotor development reflected by early touch-evoked biting, rotarod performance, and sensory gating deficits. This profile emerged with structural changes in deep layers of sensory cortices, where Pcdh9 is selectively expressed. This behavior-to-gene study implicates Pcdh9 in cognitive functions required for long-term social and nonsocial recognition. This role is supported by the involvement of Pcdh9 in sensory cortex development and sensorimotor phenotypes. Copyright © 2015 Society of Biological Psychiatry. Published

  19. Heparin-coated cardiopulmonary bypass circuits selectively deplete the pattern recognition molecule ficolin-2 of the lectin complement pathway in vivo

    DEFF Research Database (Denmark)

    Hein, Estrid; Munthe-Fog, L; Thiara, A S

    2015-01-01

    of infections. Thus, we investigated the biocompatibility of the recognition molecules of the lectin pathway in two different types of cardiopulmonary bypass circuits. Bloods were drawn at five time-points before, during and postoperatively from 30 patients undergoing elective cardiac surgery. Patients were...... randomized into two groups using different coatings of cardiopulmonary bypass circuits, Phisio® (phosphorylcholine polymer coating) and Bioline® (albumin-heparin coating). Concentrations of MBL, ficolin-1, -2 and -3 and soluble C3a and terminal complement complex (TCC) in plasma samples were measured......-2 was depleted from plasma during cardiac surgery when using heparin-coated bypass circuits and did not reach baseline level 24 h postoperation. These findings may have implications for the postoperative susceptibility to infections in patients undergoing extracorporeal circulation procedures....

  20. Left posterior BA37 is involved in object recognition: a TMS study

    DEFF Research Database (Denmark)

    Stewart, Lauren; Meyer, Bernd-Ulrich; Frith, Uta

    2001-01-01

    Functional imaging studies have proposed a role for left BA37 in phonological retrieval, semantic processing, face processing and object recognition. The present study targeted the posterior aspect of BA37 to see whether a deficit, specific to one of the above types of processing could be induced...... to name pictures when TMS was given over lBA37 compared to vertex or rBA37. rTMS over lBA37 had no significant effect on word reading, nonword reading or colour naming. The picture naming deficit is suggested to result from a disruption to object recognition processes. This study corroborates the finding...... from a recent imaging study, that the most posterior part of left hemispheric BA37 has a necessary role in object recognition....

  1. Modulation of pathogen recognition by autophagy

    Directory of Open Access Journals (Sweden)

    Ji Eun eOh

    2012-03-01

    Full Text Available Autophagy is an ancient biological process for maintaining cellular homeostasis by degradation of long-lived cytosolic proteins and organelles. Recent studies demonstrated that autophagy is availed by immune cells to regulate innate immunity. On the one hand, cells exert direct effector function by degrading intracellular pathogens; on the other hand, autophagy modulates pathogen recognition and downstream signaling for innate immune responses. Pathogen recognition via pattern recognition receptors induces autophagy. The function of phagocytic cells is enhanced by recruitment of autophagy-related proteins. Moreover, autophagy acts as a delivery system for viral replication complexes to migrate to the endosomal compartments where virus sensing occurs. In another case, key molecules of the autophagic pathway have been found to negatively regulate immune signaling, thus preventing aberrant activation of cytokine production and consequent immune responses. In this review, we focus on the recent advances in the role of autophagy in pathogen recognition and modulation of innate immune responses.

  2. Paradigms in object recognition

    International Nuclear Information System (INIS)

    Mutihac, R.; Mutihac, R.C.

    1999-09-01

    A broad range of approaches has been proposed and applied for the complex and rather difficult task of object recognition that involves the determination of object characteristics and object classification into one of many a priori object types. Our paper revises briefly the three main different paradigms in pattern recognition, namely Bayesian statistics, neural networks, and expert systems. (author)

  3. Identification of Inhibitors of Biological Interactions Involving Intrinsically Disordered Proteins

    Directory of Open Access Journals (Sweden)

    Daniela Marasco

    2015-04-01

    Full Text Available Protein–protein interactions involving disordered partners have unique features and represent prominent targets in drug discovery processes. Intrinsically Disordered Proteins (IDPs are involved in cellular regulation, signaling and control: they bind to multiple partners and these high-specificity/low-affinity interactions play crucial roles in many human diseases. Disordered regions, terminal tails and flexible linkers are particularly abundant in DNA-binding proteins and play crucial roles in the affinity and specificity of DNA recognizing processes. Protein complexes involving IDPs are short-lived and typically involve short amino acid stretches bearing few “hot spots”, thus the identification of molecules able to modulate them can produce important lead compounds: in this scenario peptides and/or peptidomimetics, deriving from structure-based, combinatorial or protein dissection approaches, can play a key role as hit compounds. Here, we propose a panoramic review of the structural features of IDPs and how they regulate molecular recognition mechanisms focusing attention on recently reported drug-design strategies in the field of IDPs.

  4. Identification of Biomolecular Building Blocks by Recognition Tunneling: Stride towards Nanopore Sequencing of Biomolecules

    Science.gov (United States)

    Sen, Suman

    DNA, RNA and Protein are three pivotal biomolecules in human and other organisms, playing decisive roles in functionality, appearance, diseases development and other physiological phenomena. Hence, sequencing of these biomolecules acquires the prime interest in the scientific community. Single molecular identification of their building blocks can be done by a technique called Recognition Tunneling (RT) based on Scanning Tunneling Microscope (STM). A single layer of specially designed recognition molecule is attached to the STM electrodes, which trap the targeted molecules (DNA nucleoside monophosphates, RNA nucleoside monophosphates or amino acids) inside the STM nanogap. Depending on their different binding interactions with the recognition molecules, the analyte molecules generate stochastic signal trains accommodating their "electronic fingerprints". Signal features are used to detect the molecules using a machine learning algorithm and different molecules can be identified with significantly high accuracy. This, in turn, paves the way for rapid, economical nanopore sequencing platform, overcoming the drawbacks of Next Generation Sequencing (NGS) techniques. To read DNA nucleotides with high accuracy in an STM tunnel junction a series of nitrogen-based heterocycles were designed and examined to check their capabilities to interact with naturally occurring DNA nucleotides by hydrogen bonding in the tunnel junction. These recognition molecules are Benzimidazole, Imidazole, Triazole and Pyrrole. Benzimidazole proved to be best among them showing DNA nucleotide classification accuracy close to 99%. Also, Imidazole reader can read an abasic monophosphate (AP), a product from depurination or depyrimidination that occurs 10,000 times per human cell per day. In another study, I have investigated a new universal reader, 1-(2-mercaptoethyl)pyrene (Pyrene reader) based on stacking interactions, which should be more specific to the canonical DNA nucleosides. In addition

  5. Control of Target Molecular Recognition in a Small Pore Space with Biomolecule-Recognition Gating Membrane.

    Science.gov (United States)

    Okuyama, Hiroto; Oshiba, Yuhei; Ohashi, Hidenori; Yamaguchi, Takeo

    2018-05-01

    A biomolecule-recognition gating membrane, which introduces thermosensitive graft polymer including molecular recognition receptor into porous membrane substrate, can close its pores by recognizing target biomolecule. The present study reports strategies for improving both versatility and sensitivity of the gating membrane. First, the membrane is fabricated by introducing the receptor via a selectively reactive click reaction improving the versatility. Second, the sensitivity of the membrane is enhanced via an active delivering method of the target molecules into the pores. In the method, the tiny signal of the target biomolecule is amplified as obvious pressure change. Furthermore, this offers 15 times higher sensitivity compared to the previously reported passive delivering method (membrane immersion to sample solution) with significantly shorter recognition time. The improvement will aid in applying the gating membrane to membrane sensors in medical fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Computational study on the inhibition mechanism of cruzain by nitrile-containing molecules.

    Science.gov (United States)

    Méndez-Lucio, Oscar; Romo-Mancillas, Antonio; Medina-Franco, José L; Castillo, Rafael

    2012-05-01

    Cysteine proteases from parasites as well as from mammals are promising drug targets for parasitic infections and systemic human diseases, respectively. Many reversible and irreversible inhibitors of this very large class of proteins have been designed. Among others, molecules with a nitrile moiety, which is a group that is susceptible to a nucleophilic attack by the enzyme, have been identified as good inhibitors. Although it is known that the nitrile group binds covalently to Cys25, there are no reports about the energetics involved in the mechanism of this process. Herein, density functional theory and quantum semi-empirical calculations were conducted in order to study the molecular recognition of cysteine proteases by nitrile-containing molecules. Results reported in this paper suggest an interaction that starts with a nucleophilic attack from the Cys25 to the inhibitor followed by a proton transfer from His162. Only one transition state was detected; however, we found the existence of an energy plateau in the potential energy surface. Based on the proposed mechanism, some structural features that could improve the biological activity of nitrile-containing molecules toward cysteine proteases are discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Structural insights into the recognition of phosphopeptide by the FHA domain of kanadaptin

    DEFF Research Database (Denmark)

    Xu, Qingping; Deller, Marc C; Nielsen, Tine K

    2014-01-01

    with a phosphopeptide mimic derived from a peptide segment from the N-terminus of a symmetry-related molecule as well as a sulfate bound to the structurally conserved phosphothreonine recognition cleft. This structure provides insights into the molecular recognition features utilized by this family of proteins...

  8. Multidimensional potential of boron-containing molecules in ...

    Indian Academy of Sciences (India)

    Administrator

    The electron deficiency of boron as compared to carbon results .... tal structure analysis of the redox pair [BMes3] o/•– confirmed .... The recognition that meta disubstitution on the benzene ring ..... embed small drug molecules, proteins, peptides and genes inside ... and healthy cells, which results in deleterious side- effects.

  9. Direct binding of autoimmune disease related T cell epitopes to purified Lewis rat MHC class II molecules

    DEFF Research Database (Denmark)

    Joosten, I; Wauben, M H; Holewijn, M C

    1994-01-01

    New strategies applied in the treatment of experimental autoimmune disease models involve blocking or modulation of MHC-peptide-TCR interactions either at the level of peptide-MHC interaction or, alternatively, at the level of T cell recognition. In order to identify useful competitor peptides one...... characteristics of the Lewis rat MHC class II RT1.B1 molecule. We have now developed a biochemical binding assay which enables competition studies in which the relative MHC binding affinity of a set of non-labelled peptides can be assessed while employing detection of biotinylated marker peptides...

  10. A Forward Genetic Screen for Molecules Involved in Pheromone-Induced Dauer Formation in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Scott J. Neal

    2016-05-01

    Full Text Available Animals must constantly assess their surroundings and integrate sensory cues to make appropriate behavioral and developmental decisions. Pheromones produced by conspecific individuals provide critical information regarding environmental conditions. Ascaroside pheromone concentration and composition are instructive in the decision of Caenorhabditis elegans to either develop into a reproductive adult or enter into the stress-resistant alternate dauer developmental stage. Pheromones are sensed by a small set of sensory neurons, and integrated with additional environmental cues, to regulate neuroendocrine signaling and dauer formation. To identify molecules required for pheromone-induced dauer formation, we performed an unbiased forward genetic screen and identified phd (pheromone response-defective dauer mutants. Here, we describe new roles in dauer formation for previously identified neuronal molecules such as the WD40 domain protein QUI-1 and MACO-1 Macoilin, report new roles for nociceptive neurons in modulating pheromone-induced dauer formation, and identify tau tubulin kinases as new genes involved in dauer formation. Thus, phd mutants define loci required for the detection, transmission, or integration of pheromone signals in the regulation of dauer formation.

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

    Science.gov (United States)

    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.

  12. Neural circuitry for rat recognition memory

    Science.gov (United States)

    Warburton, E.C.; Brown, M.W.

    2015-01-01

    Information concerning the roles of different brain regions in recognition memory processes is reviewed. The review concentrates on findings from spontaneous recognition memory tasks performed by rats, including memory for single objects, locations, object–location associations and temporal order. Particular emphasis is given to the potential roles of different regions in the circuit of interacting structures involving the perirhinal cortex, hippocampus, medial prefrontal cortex and medial dorsal thalamus in recognition memory for the association of objects and places. It is concluded that while all structures in this circuit play roles critical to such memory, these roles can potentially be differentiated and differences in the underlying synaptic and biochemical processes involved in each region are beginning to be uncovered. PMID:25315129

  13. Pattern recognition receptors and the inflammasome in kidney disease

    NARCIS (Netherlands)

    Leemans, Jaklien C.; Kors, Lotte; Anders, Hans-Joachim; Florquin, Sandrine

    2014-01-01

    Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain receptors (NLRs) are families of pattern recognition receptors that, together with inflammasomes, sense and respond to highly conserved pathogen motifs and endogenous molecules released upon cell damage or stress. Evidence

  14. Do subitizing deficits in developmental dyscalculia involve pattern recognition weakness?

    Science.gov (United States)

    Ashkenazi, Sarit; Mark-Zigdon, Nitza; Henik, Avishai

    2013-01-01

    The abilities of children diagnosed with developmental dyscalculia (DD) were examined in two types of object enumeration: subitizing, and small estimation (5-9 dots). Subitizing is usually defined as a fast and accurate assessment of a number of small dots (range 1 to 4 dots), and estimation is an imprecise process to assess a large number of items (range 5 dots or more). Based on reaction time (RT) and accuracy analysis, our results indicated a deficit in the subitizing and small estimation range among DD participants in relation to controls. There are indications that subitizing is based on pattern recognition, thus presenting dots in a canonical shape in the estimation range should result in a subitizing-like pattern. In line with this theory, our control group presented a subitizing-like pattern in the small estimation range for canonically arranged dots, whereas the DD participants presented a deficit in the estimation of canonically arranged dots. The present finding indicates that pattern recognition difficulties may play a significant role in both subitizing and subitizing deficits among those with DD. © 2012 Blackwell Publishing Ltd.

  15. A common minimal motif for the ligands of HLA-B*27 class I molecules.

    Science.gov (United States)

    Barriga, Alejandro; Lorente, Elena; Johnstone, Carolina; Mir, Carmen; del Val, Margarita; López, Daniel

    2014-01-01

    CD8(+) T cells identify and kill infected cells through the specific recognition of short viral antigens bound to human major histocompatibility complex (HLA) class I molecules. The colossal number of polymorphisms in HLA molecules makes it essential to characterize the antigen-presenting properties common to large HLA families or supertypes. In this context, the HLA-B*27 family comprising at least 100 different alleles, some of them widely distributed in the human population, is involved in the cellular immune response against pathogens and also associated to autoimmune spondyloarthritis being thus a relevant target of study. To this end, HLA binding assays performed using nine HLA-B*2705-restricted ligands endogenously processed and presented in virus-infected cells revealed a common minimal peptide motif for efficient binding to the HLA-B*27 family. The motif was independently confirmed using four unrelated peptides. This experimental approach, which could be easily transferred to other HLA class I families and supertypes, has implications for the validation of new bioinformatics tools in the functional clustering of HLA molecules, for the identification of antiviral cytotoxic T lymphocyte responses, and for future vaccine development.

  16. A common minimal motif for the ligands of HLA-B*27 class I molecules.

    Directory of Open Access Journals (Sweden)

    Alejandro Barriga

    Full Text Available CD8(+ T cells identify and kill infected cells through the specific recognition of short viral antigens bound to human major histocompatibility complex (HLA class I molecules. The colossal number of polymorphisms in HLA molecules makes it essential to characterize the antigen-presenting properties common to large HLA families or supertypes. In this context, the HLA-B*27 family comprising at least 100 different alleles, some of them widely distributed in the human population, is involved in the cellular immune response against pathogens and also associated to autoimmune spondyloarthritis being thus a relevant target of study. To this end, HLA binding assays performed using nine HLA-B*2705-restricted ligands endogenously processed and presented in virus-infected cells revealed a common minimal peptide motif for efficient binding to the HLA-B*27 family. The motif was independently confirmed using four unrelated peptides. This experimental approach, which could be easily transferred to other HLA class I families and supertypes, has implications for the validation of new bioinformatics tools in the functional clustering of HLA molecules, for the identification of antiviral cytotoxic T lymphocyte responses, and for future vaccine development.

  17. The effects of age and divided attention on spontaneous recognition.

    Science.gov (United States)

    Anderson, Benjamin A; Jacoby, Larry L; Thomas, Ruthann C; Balota, David A

    2011-05-01

    Studies of recognition typically involve tests in which the participant's memory for a stimulus is directly questioned. There are occasions however, in which memory occurs more spontaneously (e.g., an acquaintance seeming familiar out of context). Spontaneous recognition was investigated in a novel paradigm involving study of pictures and words followed by recognition judgments on stimuli with an old or new word superimposed over an old or new picture. Participants were instructed to make their recognition decision on either the picture or word and to ignore the distracting stimulus. Spontaneous recognition was measured as the influence of old vs. new distracters on target recognition. Across two experiments, older adults and younger adults placed under divided-attention showed a greater tendency to spontaneously recognize old distracters as compared to full-attention younger adults. The occurrence of spontaneous recognition is discussed in relation to ability to constrain retrieval to goal-relevant information.

  18. Electron-excited molecule interactions

    International Nuclear Information System (INIS)

    Christophorou, L.G.; Tennessee Univ., Knoxville, TN

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

  19. Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

    International Nuclear Information System (INIS)

    Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P; Zhu, R; Mayer, B; Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F; Salio, M; Shepherd, D; Polzella, P; Cerundolo, V; Dieudonne, M

    2010-01-01

    The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on α-galactosylceramide (αGalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from ∼ 25 to ∼ 160 nm, with the smaller domains corresponding to a single CD1d molecule.

  20. Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging

    Energy Technology Data Exchange (ETDEWEB)

    Duman, M; Pfleger, M; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Ebner, A; Schuetz, G J; Hinterdorfer, P [Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Zhu, R; Mayer, B [Christian Doppler Laboratory for Nanoscopic Methods in Biophysics, Institute for Biophysics, University of Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Rankl, C; Moertelmaier, M; Kada, G; Kienberger, F [Agilent Technologies Austria GmbH, Aubrunnerweg 11, A-4040 Linz (Austria); Salio, M; Shepherd, D; Polzella, P; Cerundolo, V [Cancer Research UK Tumor Immunology Group, Weatherall Institute of Molecular Medicine, Nuffield Department of Medicine, University of Oxford, Oxford OX3 9DS (United Kingdom); Dieudonne, M, E-mail: ferry_kienberger@agilent.com [Agilent Technologies Belgium, Wingepark 51, Rotselaar, AN B-3110 (Belgium)

    2010-03-19

    The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on {alpha}-galactosylceramide ({alpha}GalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from {approx} 25 to {approx} 160 nm, with the smaller domains corresponding to a single CD1d molecule.

  1. Functional network of glycan-related molecules: Glyco-Net in Glycoconjugate Data Bank

    Directory of Open Access Journals (Sweden)

    Miura Nobuaki

    2010-06-01

    Full Text Available Abstract Background Glycans are involved in a wide range of biological process, and they play an essential role in functions such as cell differentiation, cell adhesion, pathogen-host recognition, toxin-receptor interactions, signal transduction, cancer metastasis, and immune responses. Elucidating pathways related to post-translational modifications (PTMs such as glycosylation are of growing importance in post-genome science and technology. Graphical networks describing the relationships among glycan-related molecules, including genes, proteins, lipids and various biological events are considered extremely valuable and convenient tools for the systematic investigation of PTMs. However, there is no database which dynamically draws functional networks related to glycans. Description We have created a database called Glyco-Net http://www.glycoconjugate.jp/functions/, with many binary relationships among glycan-related molecules. Using search results, we can dynamically draw figures of the functional relationships among these components with nodes and arrows. A certain molecule or event corresponds to a node in the network figures, and the relationship between the molecule and the event are indicated by arrows. Since all components are treated equally, an arrow is also a node. Conclusions In this paper, we describe our new database, Glyco-Net, which is the first database to dynamically show networks of the functional profiles of glycan related molecules. The graphical networks will assist in the understanding of the role of the PTMs. In addition, since various kinds of bio-objects such as genes, proteins, and inhibitors are equally treated in Glyco-Net, we can obtain a large amount of information on the PTMs.

  2. Infant visual attention and object recognition.

    Science.gov (United States)

    Reynolds, Greg D

    2015-05-15

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Face Recognition and Tracking in Videos

    Directory of Open Access Journals (Sweden)

    Swapnil Vitthal Tathe

    2017-07-01

    Full Text Available Advancement in computer vision technology and availability of video capturing devices such as surveillance cameras has evoked new video processing applications. The research in video face recognition is mostly biased towards law enforcement applications. Applications involves human recognition based on face and iris, human computer interaction, behavior analysis, video surveillance etc. This paper presents face tracking framework that is capable of face detection using Haar features, recognition using Gabor feature extraction, matching using correlation score and tracking using Kalman filter. The method has good recognition rate for real-life videos and robust performance to changes due to illumination, environmental factors, scale, pose and orientations.

  4. Involvement of the intrinsic/default system in movement-related self recognition.

    Science.gov (United States)

    Salomon, Roy; Malach, Rafael; Lamy, Dominique

    2009-10-21

    The question of how people recognize themselves and separate themselves from the environment and others has long intrigued philosophers and scientists. Recent findings have linked regions of the 'default brain' or 'intrinsic system' to self-related processing. We used a paradigm in which subjects had to rely on subtle sensory-motor synchronization differences to determine whether a viewed movement belonged to them or to another person, while stimuli and task demands associated with the "responded self" and "responded other" conditions were precisely matched. Self recognition was associated with enhanced brain activity in several ROIs of the intrinsic system, whereas no differences emerged within the extrinsic system. This self-related effect was found even in cases where the sensory-motor aspects were precisely matched. Control conditions ruled out task difficulty as the source of the differential self-related effects. The findings shed light on the neural systems underlying bodily self recognition.

  5. Quantifying the topography of the intrinsic energy landscape of flexible biomolecular recognition

    Science.gov (United States)

    Chu, Xiakun; Gan, Linfeng; Wang, Erkang; Wang, Jin

    2013-01-01

    Biomolecular functions are determined by their interactions with other molecules. Biomolecular recognition is often flexible and associated with large conformational changes involving both binding and folding. However, the global and physical understanding for the process is still challenging. Here, we quantified the intrinsic energy landscapes of flexible biomolecular recognition in terms of binding–folding dynamics for 15 homodimers by exploring the underlying density of states, using a structure-based model both with and without considering energetic roughness. By quantifying three individual effective intrinsic energy landscapes (one for interfacial binding, two for monomeric folding), the association mechanisms for flexible recognition of 15 homodimers can be classified into two-state cooperative “coupled binding–folding” and three-state noncooperative “folding prior to binding” scenarios. We found that the association mechanism of flexible biomolecular recognition relies on the interplay between the underlying effective intrinsic binding and folding energy landscapes. By quantifying the whole global intrinsic binding–folding energy landscapes, we found strong correlations between the landscape topography measure Λ (dimensionless ratio of energy gap versus roughness modulated by the configurational entropy) and the ratio of the thermodynamic stable temperature versus trapping temperature, as well as between Λ and binding kinetics. Therefore, the global energy landscape topography determines the binding–folding thermodynamics and kinetics, crucial for the feasibility and efficiency of realizing biomolecular function. We also found “U-shape” temperature-dependent kinetic behavior and a dynamical cross-over temperature for dividing exponential and nonexponential kinetics for two-state homodimers. Our study provides a unique way to bridge the gap between theory and experiments. PMID:23754431

  6. DNA-Based Single-Molecule Electronics: From Concept to Function

    Science.gov (United States)

    2018-01-01

    Beyond being the repository of genetic information, DNA is playing an increasingly important role as a building block for molecular electronics. Its inherent structural and molecular recognition properties render it a leading candidate for molecular electronics applications. The structural stability, diversity and programmability of DNA provide overwhelming freedom for the design and fabrication of molecular-scale devices. In the past two decades DNA has therefore attracted inordinate amounts of attention in molecular electronics. This review gives a brief survey of recent experimental progress in DNA-based single-molecule electronics with special focus on single-molecule conductance and I–V characteristics of individual DNA molecules. Existing challenges and exciting future opportunities are also discussed. PMID:29342091

  7. DNA-Based Single-Molecule Electronics: From Concept to Function.

    Science.gov (United States)

    Wang, Kun

    2018-01-17

    Beyond being the repository of genetic information, DNA is playing an increasingly important role as a building block for molecular electronics. Its inherent structural and molecular recognition properties render it a leading candidate for molecular electronics applications. The structural stability, diversity and programmability of DNA provide overwhelming freedom for the design and fabrication of molecular-scale devices. In the past two decades DNA has therefore attracted inordinate amounts of attention in molecular electronics. This review gives a brief survey of recent experimental progress in DNA-based single-molecule electronics with special focus on single-molecule conductance and I-V characteristics of individual DNA molecules. Existing challenges and exciting future opportunities are also discussed.

  8. Self-oriented nanoparticles for site-selective immunoglobulin G recognition via epitope imprinting approach.

    Science.gov (United States)

    Çorman, Mehmet Emin; Armutcu, Canan; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2014-11-01

    Molecular imprinting is a polymerization technique that provides synthetic analogs for template molecules. Molecularly imprinted polymers (MIPs) have gained much attention due to their unique properties such as selectivity and specificity for target molecules. In this study, we focused on the development of polymeric materials with molecular recognition ability, so molecular imprinting was combined with miniemulsion polymerization to synthesize self-orienting nanoparticles through the use of an epitope imprinting approach. Thus, L-lysine imprinted nanoparticles (LMIP) were synthesized via miniemulsion polymerization technique. Immunoglobulin G (IgG) was then bound to the cavities that specifically formed for L-lysine molecules that are typically found at the C-terminus of the Fc region of antibody molecules. The resulting nanoparticles makes it possible to minimize the nonspecific interaction between monomer and template molecules. In addition, the orientation of the entire IgG molecule was controlled, and random imprinting of the IgG was prevented. The optimum conditions were determined for IgG recognition using the imprinted nanoparticles. The selectivity of the nanoparticles against IgG molecules was also evaluated using albumin and hemoglobin as competitor molecules. In order to show the self-orientation capability of imprinted nanoparticles, human serum albumin (HSA) adsorption onto both the plain nanoparticles and immobilized nanoparticles by anti-human serum albumin antibody (anti-HSA antibody) was also carried out. Due to anti-HSA antibody immobilization on the imprinted nanoparticles, the adsorption capability of nanoparticles against HSA molecules vigorously enhanced. It is proved that the oriented immobilization of antibodies was appropriately succeeded. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Molecular recognition by gold, silver and copper nanoparticles

    Science.gov (United States)

    Tauran, Yannick; Brioude, Arnaud; Coleman, Anthony W; Rhimi, Moez; Kim, Beonjoom

    2013-01-01

    The intrinsic physical properties of the noble metal nanoparticles, which are highly sensitive to the nature of their local molecular environment, make such systems ideal for the detection of molecular recognition events. The current review describes the state of the art concerning molecular recognition of Noble metal nanoparticles. In the first part the preparation of such nanoparticles is discussed along with methods of capping and stabilization. A brief discussion of the three common methods of functionalization: Electrostatic adsorption; Chemisorption; Affinity-based coordination is given. In the second section a discussion of the optical and electrical properties of nanoparticles is given to aid the reader in understanding the use of such properties in molecular recognition. In the main section the various types of capping agents for molecular recognition; nucleic acid coatings, protein coatings and molecules from the family of supramolecular chemistry are described along with their numerous applications. Emphasis for the nucleic acids is on complementary oligonucleotide and aptamer recognition. For the proteins the recognition properties of antibodies form the core of the section. With respect to the supramolecular systems the cyclodextrins, calix[n]arenes, dendrimers, crown ethers and the cucurbitales are treated in depth. Finally a short section deals with the possible toxicity of the nanoparticles, a concern in public health. PMID:23977421

  10. Upregulation of adhesion molecules on leukemia targets improves the efficacy of cytotoxic T cells transduced with chimeric anti-CD19 receptor.

    Science.gov (United States)

    Laurin, David; Marin, Virna; Biagi, Ettore; Pizzitola, Irene; Agostoni, Valentina; Gallot, Géraldine; Vié, Henri; Jacob, Marie Christine; Chaperot, Laurence; Aspord, Caroline; Plumas, Joël

    2013-04-01

    T lymphocytes engineered to express chimeric antigen receptors (CARs) interact directly with cell surface molecules, bypassing MHC antigen presentation dependence. We generated human anti-CD19ζ CAR cytotoxic T lymphocytes and cytokine-induced killer cells and studied their sensitivity to the expression of adhesion molecules for the killing of primary B-lineage acute lymphoblastic leukemia (B-ALL) targets. Despite a very low basal expression of surface adhesion molecules, B-ALL blasts were lysed by the anti-CD19ζ-CAR transduced effectors as expected. We next investigated the regulatory role of adhesion molecules during CAR-mediated cytolysis. The blocking of these accessory molecules strongly limited the chimeric effector's cytotoxicity. Thereafter, B-ALL cells surface adhesion molecule level expression was induced by IFN-γ or by the combined use of CD40L and IL-4 and the cells were submitted to anti-CD19ζ-CAR transduced effectors lysis. Upregulation of adhesion molecules expression by blasts potentiated their killing. The improved cytotoxicity observed was dependent on target surface expression of adhesion molecules, particularly CD54. Taken together, these results indicate that adhesion molecules, and principally CD54, are involved in the efficiency of recognition by effector chimeric ζ. These observations have potential implications for the design of immunotherapy treatment approaches for hematological malignancies and tumors based on the adoption of CAR effector cells.

  11. Participation, Recognition and the Democratic Doxa

    DEFF Research Database (Denmark)

    Harrits, Gitte Sommer

    2006-01-01

    to the exclusionary effects of norms of citizenship, i.e. the exclusionfrom within, and suggest the recognition of group differences. This paper tries to suggest, how a Bourdieu-perspective can help bridge the gap of dichotomies such as individual/group, universalism/particularism and rights/recognition. The paper...... suggest that a democratisation of the political doxa, involving the recognition of differences in political habitus and (most importantly) practices is necessary to oppose the tendencies of exclusion and to further a widespread empowerment of citizens in late modern societies, without this turing...

  12. Pattern recognition and classification an introduction

    CERN Document Server

    Dougherty, Geoff

    2012-01-01

    The use of pattern recognition and classification is fundamental to many of the automated electronic systems in use today. However, despite the existence of a number of notable books in the field, the subject remains very challenging, especially for the beginner. Pattern Recognition and Classification presents a comprehensive introduction to the core concepts involved in automated pattern recognition. It is designed to be accessible to newcomers from varied backgrounds, but it will also be useful to researchers and professionals in image and signal processing and analysis, and in computer visi

  13. New domains of neural cell-adhesion molecule L1 implicated in X-linked hydrocephalus and MASA syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Jouet, M.; Kenwick, S. [Univ. of Cambridge (United Kingdom); Moncla, A. [Hopital d`Enfants de la Timone, Marseillas (United Kingdom)] [and others

    1995-06-01

    The neural cell-adhesion molecule L1 is involved in intercellular recognition and neuronal migration in the CNS. Recently, we have shown that mutations in the gene encoding L1 are responsible for three related disorders; X-linked hydrocephalus, MASA (mental retardation, aphasia, shuffling gait, and adducted thumbs) syndrome, and spastic paraplegia type I (SPG1). These three disorders represent a clinical spectrum that varies not only between families but sometimes also within families. To date, 14 independent L1 mutations have been reported and shown to be disease causing. Here we report nine novel L1 mutations in X-linked hydrocephalus and MASA-syndrome families, including the first examples of mutations affecting the fibronectin type III domains of the molecule. They are discussed in relation both to phenotypes and to the insights that they provide into L1 function. 39 refs., 5 figs., 3 tabs.

  14. Cyclophilin C Participates in the US2-Mediated Degradation of Major Histocompatibility Complex Class I Molecules.

    Science.gov (United States)

    Chapman, Daniel C; Stocki, Pawel; Williams, David B

    2015-01-01

    Human cytomegalovirus uses a variety of mechanisms to evade immune recognition through major histocompatibility complex class I molecules. One mechanism mediated by the immunoevasin protein US2 causes rapid disposal of newly synthesized class I molecules by the endoplasmic reticulum-associated degradation pathway. Although several components of this degradation pathway have been identified, there are still questions concerning how US2 targets class I molecules for degradation. In this study we identify cyclophilin C, a peptidyl prolyl isomerase of the endoplasmic reticulum, as a component of US2-mediated immune evasion. Cyclophilin C could be co-isolated with US2 and with the class I molecule HLA-A2. Furthermore, it was required at a particular expression level since depletion or overexpression of cyclophilin C impaired the degradation of class I molecules. To better characterize the involvement of cyclophilin C in class I degradation, we used LC-MS/MS to detect US2-interacting proteins that were influenced by cyclophilin C expression levels. We identified malectin, PDIA6, and TMEM33 as proteins that increased in association with US2 upon cyclophilin C knockdown. In subsequent validation all were shown to play a functional role in US2 degradation of class I molecules. This was specific to US2 rather than general ER-associated degradation since depletion of these proteins did not impede the degradation of a misfolded substrate, the null Hong Kong variant of α1-antitrypsin.

  15. Dielectric and ferroelectric sensing based on molecular recognition in Cu(1,10-phenlothroline)2SeO4.(diol) systems

    Science.gov (United States)

    Ye, Heng-Yun; Liao, Wei-Qiang; Zhou, Qionghua; Zhang, Yi; Wang, Jinlan; You, Yu-Meng; Wang, Jin-Yun; Chen, Zhong-Ning; Li, Peng-Fei; Fu, Da-Wei; Huang, Songping D.; Xiong, Ren-Gen

    2017-02-01

    The process of molecular recognition is the assembly of two or more molecules through weak interactions. Information in the process of molecular recognition can be transmitted to us via physical signals, which may find applications in sensing and switching. The conventional signals are mainly limited to light signal. Here, we describe the recognition of diols with Cu(1,10-phenlothroline)2SeO4 and the transduction of discrete recognition events into dielectric and/or ferroelectric signals. We observe that systems of Cu(1,10-phenlothroline)2SeO4.(diol) exhibit significant dielectric and/or ferroelectric dependence on different diol molecules. The compounds including ethane-1,2-diol or propane-1,2-diol just show small temperature-dependent dielectric anomalies and no reversible polarization, while the compound including ethane-1,3-diol shows giant temperature-dependent dielectric anomalies as well as ferroelectric reversible spontaneous polarization. This finding shows that dielectricity and/or ferroelectricity has the potential to be used for signalling molecular recognition.

  16. Genes related to antioxidant metabolism are involved in Methylobacterium mesophilicum-soybean interaction.

    Science.gov (United States)

    Araújo, Welington Luiz; Santos, Daiene Souza; Dini-Andreote, Francisco; Salgueiro-Londoño, Jennifer Katherine; Camargo-Neves, Aline Aparecida; Andreote, Fernando Dini; Dourado, Manuella Nóbrega

    2015-10-01

    The genus Methylobacterium is composed of pink-pigmented methylotrophic bacterial species that are widespread in natural environments, such as soils, stream water and plants. When in association with plants, this genus colonizes the host plant epiphytically and/or endophytically. This association is known to promote plant growth, induce plant systemic resistance and inhibit plant infection by phytopathogens. In the present study, we focused on evaluating the colonization of soybean seedling-roots by Methylobacterium mesophilicum strain SR1.6/6. We focused on the identification of the key genes involved in the initial step of soybean colonization by methylotrophic bacteria, which includes the plant exudate recognition and adaptation by planktonic bacteria. Visualization by scanning electron microscopy revealed that M. mesophilicum SR1.6/6 colonizes soybean roots surface effectively at 48 h after inoculation, suggesting a mechanism for root recognition and adaptation before this period. The colonization proceeds by the development of a mature biofilm on roots at 96 h after inoculation. Transcriptomic analysis of the planktonic bacteria (with plant) revealed the expression of several genes involved in membrane transport, thus confirming an initial metabolic activation of bacterial responses when in the presence of plant root exudates. Moreover, antioxidant genes were mostly expressed during the interaction with the plant exudates. Further evaluation of stress- and methylotrophic-related genes expression by qPCR showed that glutathione peroxidase and glutathione synthetase genes were up-regulated during the Methylobacterium-soybean interaction. These findings support that glutathione (GSH) is potentially a key molecule involved in cellular detoxification during plant root colonization. In addition to methylotrophic metabolism, antioxidant genes, mainly glutathione-related genes, play a key role during soybean exudate recognition and adaptation, the first step in

  17. Recognition, survival and persistence of Staphylococcus aureus in the model host Tenebrio molitor.

    Science.gov (United States)

    Dorling, Jack; Moraes, Caroline; Rolff, Jens

    2015-02-01

    The degree of specificity of any given immune response to a parasite is governed by the complexity and variation of interactions between host and pathogen derived molecules. Here, we assess the extent to which recognition and immuno-resistance of cell wall mutants of the pathogen Staphylococcus aureus may contribute to establishment and maintenance of persistent infection in the model insect host, Tenebrio molitor. The cell surface of S. aureus is decorated with various molecules, including glycopolymers such as wall teichoic acid (WTA). WTA is covalently bound to peptidoglycan (PGN) and its absence has been associated with increased recognition of PGN by host receptors (PGRPs). WTA is also further modified by other molecules such as D-alanine (D-alanylation). Both the level of WTA expression and its D-alanylation were found to be important in the mediation of the host-parasite interaction in this model system. Specifically, WTA itself was seen to influence immune recognition, while D-alanylation of WTA was found to increase immuno-resistance and was associated with prolonged persistence of S. aureus in T. molitor. These results implicate WTA and its D-alanylation as important factors in the establishment and maintenance of persistent infection, affecting different critical junctions in the immune response; through potential evasion of recognition by PGRPs and resistance to humoral immune effectors during prolonged exposure to the immune system. This highlights a mechanism by which specificity in this host-parasite interaction may arise. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Chiral recognition and determination of enantiomeric excess by mass spectrometry: A review

    International Nuclear Information System (INIS)

    Yu, Xiangying; Yao, Zhong-Ping

    2017-01-01

    Chiral analysis is of great importance to fundamental and applied research in chemical, biological and pharmaceutical sciences. Due to the superiority of mass spectrometry (MS) over other analytical methods in terms of speed, specificity and sensitivity, chiral analysis by MS has attracted much interest in recent years. Chiral analysis by MS typically involves introduction of a chiral selector to form diastereomers with analyte enantiomers, and comparison of the behaviors of diastereomers in MS. Chiral differentiation can be achieved by comparing the relative abundances of diastereomers, the thermodynamic or kinetic constants of ion-molecule reactions of diastereomers in the gas phase, the dissociation of diastereomers in MS/MS, or the mobility of diastereomers in ion mobility mass spectrometry. In this review, chiral recognition and determination of enantiomeric excess by these chiral MS methods were summarized, and the prospects of chiral analysis by MS were discussed. - Highlights: • Both chiral recognition and determination of enantiomeric excess by mass spectrometry are systematically reviewed. • Classification is based on the behavioral differences of diastereomers formed between chiral analytes and chiral selectors. • Development of ion mobility mass spectrometry for chiral differentiation is covered. • Various methods are highlighted and compared.

  19. Chiral recognition and determination of enantiomeric excess by mass spectrometry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Xiangying [College of Pharmacy, Jinan University, Guangzhou 510632, Guangdong (China); State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation) and Shenzhen Key Laboratory of Food Biological Safety Control, Shenzhen Research Institute of Hong Kong Polytechnic University, Shenzhen 518057 (China); Yao, Zhong-Ping, E-mail: zhongping.yao@polyu.edu.hk [State Key Laboratory of Chinese Medicine and Molecular Pharmacology (Incubation) and Shenzhen Key Laboratory of Food Biological Safety Control, Shenzhen Research Institute of Hong Kong Polytechnic University, Shenzhen 518057 (China); Key Laboratory of Natural Resources of Changbai Mountain and Functional Molecules (Yanbian University), Ministry of Education, Yanji 133002, Jilin (China); State Key Laboratory of Chirosciences, Food Safety and Technology Research Centre and Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region (China)

    2017-05-22

    Chiral analysis is of great importance to fundamental and applied research in chemical, biological and pharmaceutical sciences. Due to the superiority of mass spectrometry (MS) over other analytical methods in terms of speed, specificity and sensitivity, chiral analysis by MS has attracted much interest in recent years. Chiral analysis by MS typically involves introduction of a chiral selector to form diastereomers with analyte enantiomers, and comparison of the behaviors of diastereomers in MS. Chiral differentiation can be achieved by comparing the relative abundances of diastereomers, the thermodynamic or kinetic constants of ion-molecule reactions of diastereomers in the gas phase, the dissociation of diastereomers in MS/MS, or the mobility of diastereomers in ion mobility mass spectrometry. In this review, chiral recognition and determination of enantiomeric excess by these chiral MS methods were summarized, and the prospects of chiral analysis by MS were discussed. - Highlights: • Both chiral recognition and determination of enantiomeric excess by mass spectrometry are systematically reviewed. • Classification is based on the behavioral differences of diastereomers formed between chiral analytes and chiral selectors. • Development of ion mobility mass spectrometry for chiral differentiation is covered. • Various methods are highlighted and compared.

  20. Dissociative electron attachment to vibrationally excited H2 molecules involving the 2Σg+ resonant Rydberg electronic state

    International Nuclear Information System (INIS)

    Celiberto, R.; Janev, R.K.; Wadehra, J.M.; Tennyson, J.

    2012-01-01

    Graphical abstract: Dissociative electron attachment cross sections as a function of the incident electron energy and for the initial vibration levels v i = 0–5, 10 of the H 2 molecule. Highlights: ► We calculated electron–hydrogen dissociative attachment cross sections and rates coefficients. ► Collision processes occurring through a resonant Rydberg state are considered. ► Cross sections and rates were obtained for vibrationally excited hydrogen molecules. ► The cross sections exhibit pronounced oscillatory structures. ► A comparison with the process involving the electron–hydrogen resonant ground state is discussed. - Abstract: Dissociative electron attachment cross sections (DEA) on vibrationally excited H 2 molecule taking place via the 2 Σ g + Rydberg-excited resonant state are studied using the local complex potential (LCP) model for resonant collisions. The cross sections are calculated for all initial vibrational levels (v i = 0–14) of the neutral molecule. In contrast to the previously noted dramatic increase in the DEA cross sections with increasing v i , when the process proceeds via the X 2 Σ u + shape resonance of H 2 , for the 2 Σ g + Rydberg resonance the cross sections increase only gradually up to v i = 3 and then decrease. Moreover, the cross sections for v i ⩾ 6 exhibit pronounced oscillatory structures. A discussion of the origin of the observed behavior of calculated cross sections is given. The DEA rate coefficients for all v i levels are also calculated in the 0.5–1000 eV temperature range.

  1. Involvement of HLA class I molecules in the immune escape of urologic tumors.

    Science.gov (United States)

    Carretero, R; Gil-Julio, H; Vázquez-Alonso, F; Garrido, F; Castiñeiras, J; Cózar, J M

    2014-04-01

    To analyze the influence of different alterations in human leukocyte antigen class I molecules (HLA I) in renal cell carcinoma, as well as in bladder and prostate cancer. We also study the correlation between HLA I expression and the progression of the disease and the response after immunotherapy protocols. It has been shown, experimentally, that the immune system can recognize and kill neoplastic cells. By analyzing the expression of HLA I molecules on the surface of cancer cells, we were able to study the tumor escape mechanisms against the immune system. Alteration or irreversible damage in HLA I molecules is used by the neoplastic cells to escape the immune system. The function of these molecules is to recognize endogenous peptides and present them to T cells of the immune system. There is a clear relationship between HLA I reversible alterations and success of therapy. Irreversible lesions also imply a lack of response to treatment. The immune system activation can reverse HLA I molecules expression in tumors with reversible lesions, whereas tumors with irreversible ones do not respond to such activation. Determine the type of altered HLA I molecules in tumors is of paramount importance when choosing the type of treatment to keep looking for therapeutic success. Those tumors with reversible lesions can be treated with traditional immunotherapy; however, tumour with irreversible alterations should follow alternative protocols, such as the use of viral vectors carrying the HLA genes to achieve damaged re-expression of the protein. From studies in urologic tumors, we can conclude that the HLA I molecules play a key role in these tumors escape to the immune system. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

  2. The Medial Dorsal Thalamic Nucleus and the Medial Prefrontal Cortex of the Rat Function Together to Support Associative Recognition and Recency but Not Item Recognition

    Science.gov (United States)

    Cross, Laura; Brown, Malcolm W.; Aggleton, John P.; Warburton, E. Clea

    2013-01-01

    In humans recognition memory deficits, a typical feature of diencephalic amnesia, have been tentatively linked to mediodorsal thalamic nucleus (MD) damage. Animal studies have occasionally investigated the role of the MD in single-item recognition, but have not systematically analyzed its involvement in other recognition memory processes. In…

  3. Pathogen recognition in the innate immune response.

    Science.gov (United States)

    Kumar, Himanshu; Kawai, Taro; Akira, Shizuo

    2009-04-28

    Immunity against microbial pathogens primarily depends on the recognition of pathogen components by innate receptors expressed on immune and non-immune cells. Innate receptors are evolutionarily conserved germ-line-encoded proteins and include TLRs (Toll-like receptors), RLRs [RIG-I (retinoic acid-inducible gene-I)-like receptors] and NLRs (Nod-like receptors). These receptors recognize pathogens or pathogen-derived products in different cellular compartments, such as the plasma membrane, the endosomes or the cytoplasm, and induce the expression of cytokines, chemokines and co-stimulatory molecules to eliminate pathogens and instruct pathogen-specific adaptive immune responses. In the present review, we will discuss the recent progress in the study of pathogen recognition by TLRs, RLRs and NLRs and their signalling pathways.

  4. Modes of Interaction of Pleckstrin Homology Domains with Membranes: Toward a Computational Biochemistry of Membrane Recognition.

    Science.gov (United States)

    Naughton, Fiona B; Kalli, Antreas C; Sansom, Mark S P

    2018-02-02

    Pleckstrin homology (PH) domains mediate protein-membrane interactions by binding to phosphatidylinositol phosphate (PIP) molecules. The structural and energetic basis of selective PH-PIP interactions is central to understanding many cellular processes, yet the molecular complexities of the PH-PIP interactions are largely unknown. Molecular dynamics simulations using a coarse-grained model enables estimation of free-energy landscapes for the interactions of 12 different PH domains with membranes containing PIP 2 or PIP 3 , allowing us to obtain a detailed molecular energetic understanding of the complexities of the interactions of the PH domains with PIP molecules in membranes. Distinct binding modes, corresponding to different distributions of cationic residues on the PH domain, were observed, involving PIP interactions at either the "canonical" (C) and/or "alternate" (A) sites. PH domains can be grouped by the relative strength of their C- and A-site interactions, revealing that a higher affinity correlates with increased C-site interactions. These simulations demonstrate that simultaneous binding of multiple PIP molecules by PH domains contributes to high-affinity membrane interactions, informing our understanding of membrane recognition by PH domains in vivo. Copyright © 2017. Published by Elsevier Ltd.

  5. Multiple Levels of Recognition in Ants: A Feature of Complex Societies

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia

    2008-01-01

    diverse. In ants, social interactions are regulated by at least three levels of recognition. Nestmate recognition occurs between colonies, is very effective, and involves fast processing. Within a colony, division of labor is enhanced by recognition of different classes of individuals. Ultimately......, in particular circumstances, such as cooperative colony founding with stable dominance hierarchies, ants are capable of individual recognition. The underlying recognition cues and mechanisms appear to be specific to each recognition level, and their integrated understanding could contribute...

  6. Physiological arousal in processing recognition information

    Directory of Open Access Journals (Sweden)

    Guy Hochman

    2010-07-01

    Full Text Available The recognition heuristic (RH; Goldstein and Gigerenzer, 2002 suggests that, when applicable, probabilistic inferences are based on a noncompensatory examination of whether an object is recognized or not. The overall findings on the processes that underlie this fast and frugal heuristic are somewhat mixed, and many studies have expressed the need for considering a more compensatory integration of recognition information. Regardless of the mechanism involved, it is clear that recognition has a strong influence on choices, and this finding might be explained by the fact that recognition cues arouse affect and thus receive more attention than cognitive cues. To test this assumption, we investigated whether recognition results in a direct affective signal by measuring physiological arousal (i.e., peripheral arterial tone in the established city-size task. We found that recognition of cities does not directly result in increased physiological arousal. Moreover, the results show that physiological arousal increased with increasing inconsistency between recognition information and additional cue information. These findings support predictions derived by a compensatory Parallel Constraint Satisfaction model rather than predictions of noncompensatory models. Additional results concerning confidence ratings, response times, and choice proportions further demonstrated that recognition information and other cognitive cues are integrated in a compensatory manner.

  7. The Influence of Emotion on Recognition Memory for Scenes

    OpenAIRE

    Pryde, Beatrice

    2012-01-01

    According to dual-process models, recognition memory is supported by two distinct processes: familiarity, a relatively automatic process that involves the retrieval of a previously encountered item, and recollection, a more effortful process that involves the retrieval of information associated with the context in which an item was encoded (Mickes, Wais & Wixted, 2009). There is a wealth of research suggesting that recognition memory performance is affected by the emotional content of stimul...

  8. How similar are recognition memory and inductive reasoning?

    Science.gov (United States)

    Hayes, Brett K; Heit, Evan

    2013-07-01

    Conventionally, memory and reasoning are seen as different types of cognitive activities driven by different processes. In two experiments, we challenged this view by examining the relationship between recognition memory and inductive reasoning involving multiple forms of similarity. A common study set (members of a conjunctive category) was followed by a test set containing old and new category members, as well as items that matched the study set on only one dimension. The study and test sets were presented under recognition or induction instructions. In Experiments 1 and 2, the inductive property being generalized was varied in order to direct attention to different dimensions of similarity. When there was no time pressure on decisions, patterns of positive responding were strongly affected by property type, indicating that different types of similarity were driving recognition and induction. By comparison, speeded judgments showed weaker property effects and could be explained by generalization based on overall similarity. An exemplar model, GEN-EX (GENeralization from EXamples), could account for both the induction and recognition data. These findings show that induction and recognition share core component processes, even when the tasks involve flexible forms of similarity.

  9. Lessons learned from mice deficient in lectin complement pathway molecules

    DEFF Research Database (Denmark)

    Genster, Ninette; Takahashi, Minoru; Sekine, Hideharu

    2014-01-01

    in turn activate downstream complement components, ultimately leading to elimination of the pathogen. Mice deficient in the key molecules of lectin pathway of complement have been generated in order to build knowledge of the molecular mechanisms of the lectin pathway in health and disease. Despite......The lectin pathway of the complement system is initiated when the pattern-recognition molecules, mannose-binding lectin (MBL), ficolins or collectin-11, bind to invading pathogens or damaged host cells. This leads to activation of MBL/ficolin/collectin-11 associated serine proteases (MASPs), which...... differences in the genetic arrangements of murine and human orthologues of lectin pathway molecules, the knockout mice have proven to be valuable models to explore the effect of deficiency states in humans. In addition, new insight and unexpected findings on the diverse roles of lectin pathway molecules...

  10. The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica: Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis*

    Science.gov (United States)

    Cwiklinski, Krystyna; de la Torre-Escudero, Eduardo; Trelis, Maria; Bernal, Dolores; Dufresne, Philippe J.; Brennan, Gerard P.; O'Neill, Sandra; Tort, Jose; Paterson, Steve; Marcilla, Antonio; Dalton, John P.; Robinson, Mark W.

    2015-01-01

    Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterization of the total secretome of this zoonotic parasite. Fasciola secretes at least two subpopulations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialized cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies within the tegumental syncytium and carry many previously described immunomodulatory molecules that could be delivered into host cells. By integrating our proteomics data with recently available transcriptomic data sets we have detailed the pathways involved with EV biogenesis in F. hepatica and propose that the small exosome biogenesis occurs via ESCRT-dependent MVB formation in the tegumental syncytium before being shed from the apical plasma membrane. Furthermore, we found that the molecular “machinery” required for EV biogenesis is constitutively expressed across the intramammalian development stages of the parasite. By contrast, the cargo molecules packaged within the EVs are developmentally regulated, most likely to facilitate the parasites migration through host tissue and to counteract host immune attack. PMID:26486420

  11. Formation of Ultracold Molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cote, Robin [Univ. of Connecticut, Storrs, CT (United States)

    2016-01-28

    Advances in our ability to slow down and cool atoms and molecules to ultracold temperatures have paved the way to a revolution in basic research on molecules. Ultracold molecules are sensitive of very weak interactions, even when separated by large distances, which allow studies of the effect of those interactions on the behavior of molecules. In this program, we have explored ways to form ultracold molecules starting from pairs of atoms that have already reached the ultracold regime. We devised methods that enhance the efficiency of ultracold molecule production, for example by tuning external magnetic fields and using appropriate laser excitations. We also investigates the properties of those ultracold molecules, especially their de-excitation into stable molecules. We studied the possibility of creating new classes of ultra-long range molecules, named macrodimers, thousand times more extended than regular molecules. Again, such objects are possible because ultra low temperatures prevent their breakup by collision. Finally, we carried out calculations on how chemical reactions are affected and modified at ultracold temperatures. Normally, reactions become less effective as the temperature decreases, but at ultracold temperatures, they can become very effective. We studied this counter-intuitive behavior for benchmark chemical reactions involving molecular hydrogen.

  12. Bio-specific recognition and applications: from molecular to colloidal scales

    International Nuclear Information System (INIS)

    Baudry, Jean; Bertrand, Emanuel; Lequeux, Nicolas; Bibette, Jerome

    2004-01-01

    Biomolecules have the well-known ability to build reversible complexes. Indeed, antigens and antibodies or adhesion molecules are able to recognize one another with a strong affinity and a very high specificity. This paper first reviews the various techniques and related results about binding and unbinding, at the scale of a unique ligand/receptor couple. One important biotechnological application arising from these recognition phenomena concerns immuno-diagnosis, which is essentially based on the formation of these specific complexes. We show how the physics of colloids associated with the growing scientific background concerning molecular recognition helps in rationalizing and inventing new diagnostic strategies. Finally the concept of colloidal self-assembling systems as biosensors is presented as directly impacting the most important questions related to molecular recognition and their biotechnological implications. (topical review)

  13. Mobile Visual Recognition on Smartphones

    Directory of Open Access Journals (Sweden)

    Zhenwen Gui

    2013-01-01

    Full Text Available This paper addresses the recognition of large-scale outdoor scenes on smartphones by fusing outputs of inertial sensors and computer vision techniques. The main contributions can be summarized as follows. Firstly, we propose an ORD (overlap region divide method to plot image position area, which is fast enough to find the nearest visiting area and can also reduce the search range compared with the traditional approaches. Secondly, the vocabulary tree-based approach is improved by introducing GAGCC (gravity-aligned geometric consistency constraint. Our method involves no operation in the high-dimensional feature space and does not assume a global transform between a pair of images. Thus, it substantially reduces the computational complexity and memory usage, which makes the city scale image recognition feasible on the smartphone. Experiments on a collected database including 0.16 million images show that the proposed method demonstrates excellent recognition performance, while maintaining the average recognition time about 1 s.

  14. Material recognition based on thermal cues: Mechanisms and applications.

    Science.gov (United States)

    Ho, Hsin-Ni

    2018-01-01

    Some materials feel colder to the touch than others, and we can use this difference in perceived coldness for material recognition. This review focuses on the mechanisms underlying material recognition based on thermal cues. It provides an overview of the physical, perceptual, and cognitive processes involved in material recognition. It also describes engineering domains in which material recognition based on thermal cues have been applied. This includes haptic interfaces that seek to reproduce the sensations associated with contact in virtual environments and tactile sensors aim for automatic material recognition. The review concludes by considering the contributions of this line of research in both science and engineering.

  15. Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity

    Energy Technology Data Exchange (ETDEWEB)

    Rudenko, Gabby (Texas-MED)

    2017-01-01

    Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, formingtrans-complexes spanning the synaptic cleft orcis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.

  16. Dorsal stream involvement in recognition of objects with transient onset but not with ramped onset

    Directory of Open Access Journals (Sweden)

    Lourenco Tomas

    2011-08-01

    Full Text Available Abstract Background Although the ventral visual stream is understood to be responsible for object recognition, it has been proposed that the dorsal stream may contribute to object recognition by rapidly activating parietal attention mechanisms, prior to ventral stream object processing. Methods To investigate the relative contribution of the dorsal visual stream to object recognition a group of tertiary students were divided into good and poor motion coherence groups and assessed on tasks classically assumed to rely on ventral stream processing. Participants were required to identify simple line drawings in two tasks, one where objects were presented abruptly for 50 ms followed by a white-noise mask, the other where contrast was linearly ramped on and off over 325 ms and replaced with a mask. Results Although both groups only differed in motion coherence performance (a dorsal stream measure, the good motion coherence group showed superior contrast sensitivity for object recognition on the abrupt, but not the ramped presentation tasks. Conclusions We propose that abrupt presentation of objects activated attention mechanisms fed by the dorsal stream, whereas the ramped presentation had reduced transience and thus did not activate dorsal attention mechanisms as well. The results suggest that rapid dorsal stream activation may be required to assist with ventral stream object processing.

  17. Object recognition memory: neurobiological mechanisms of encoding, consolidation and retrieval.

    Science.gov (United States)

    Winters, Boyer D; Saksida, Lisa M; Bussey, Timothy J

    2008-07-01

    Tests of object recognition memory, or the judgment of the prior occurrence of an object, have made substantial contributions to our understanding of the nature and neurobiological underpinnings of mammalian memory. Only in recent years, however, have researchers begun to elucidate the specific brain areas and neural processes involved in object recognition memory. The present review considers some of this recent research, with an emphasis on studies addressing the neural bases of perirhinal cortex-dependent object recognition memory processes. We first briefly discuss operational definitions of object recognition and the common behavioural tests used to measure it in non-human primates and rodents. We then consider research from the non-human primate and rat literature examining the anatomical basis of object recognition memory in the delayed nonmatching-to-sample (DNMS) and spontaneous object recognition (SOR) tasks, respectively. The results of these studies overwhelmingly favor the view that perirhinal cortex (PRh) is a critical region for object recognition memory. We then discuss the involvement of PRh in the different stages--encoding, consolidation, and retrieval--of object recognition memory. Specifically, recent work in rats has indicated that neural activity in PRh contributes to object memory encoding, consolidation, and retrieval processes. Finally, we consider the pharmacological, cellular, and molecular factors that might play a part in PRh-mediated object recognition memory. Recent studies in rodents have begun to indicate the remarkable complexity of the neural substrates underlying this seemingly simple aspect of declarative memory.

  18. Nitrogen modulation of legume root architecture signalling pathways involves phytohormones and small regulatory molecules

    Directory of Open Access Journals (Sweden)

    Nadiatul Akmal Mohd-Radzman

    2013-10-01

    Full Text Available Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

  19. Nitrogen modulation of legume root architecture signaling pathways involves phytohormones and small regulatory molecules.

    Science.gov (United States)

    Mohd-Radzman, Nadiatul A; Djordjevic, Michael A; Imin, Nijat

    2013-10-01

    Nitrogen, particularly nitrate is an important yield determinant for crops. However, current agricultural practice with excessive fertilizer usage has detrimental effects on the environment. Therefore, legumes have been suggested as a sustainable alternative for replenishing soil nitrogen. Legumes can uniquely form nitrogen-fixing nodules through symbiotic interaction with specialized soil bacteria. Legumes possess a highly plastic root system which modulates its architecture according to the nitrogen availability in the soil. Understanding how legumes regulate root development in response to nitrogen availability is an important step to improving root architecture. The nitrogen-mediated root development pathway starts with sensing soil nitrogen level followed by subsequent signal transduction pathways involving phytohormones, microRNAs and regulatory peptides that collectively modulate the growth and shape of the root system. This review focuses on the current understanding of nitrogen-mediated legume root architecture including local and systemic regulations by different N-sources and the modulations by phytohormones and small regulatory molecules.

  20. Labelled molecules, modern research implements

    International Nuclear Information System (INIS)

    Pichat, L.; Langourieux, Y.

    1974-01-01

    Details of the synthesis of carbon 14- and tritium-labelled molecules are examined. Although the methods used are those of classical organic chemistry the preparation of carbon 14-labelled molecules differs in some respects, most noticeably in the use of 14 CO 2 which requires very special handling techniques. For the tritium labelling of organic molecules the methods are somewhat different, very often involving exchange reactions. The following are described in turn: the so-called Wilzbach exchange method; exchange by catalysis in solution; catalytic hydrogenation with tritium; reductions with borotritides. Some applications of labelled molecules in organic chemistry, biochemistry and pharmacology are listed [fr

  1. Binding of neutral molecules by p-nitrophenylureido substituted calix[4]arenes

    Czech Academy of Sciences Publication Activity Database

    Cuřínová, P.; Pojarová, M.; Budka, J.; Lang, Kamil; Stibor, I.; Lhoták, P.

    2010-01-01

    Roč. 66, č. 40 (2010), s. 8047-8050 ISSN 0040-4020 R&D Projects: GA ČR GA203/09/0691 Institutional research plan: CEZ:AV0Z40320502 Keywords : calixarene * recognition * neutral molecules binding * X-ray crystallography Subject RIV: CA - Inorganic Chemistry Impact factor: 3.011, year: 2010

  2. Pattern Recognition via the Toll-Like Receptor System in the Human Female Genital Tract

    Directory of Open Access Journals (Sweden)

    Kaei Nasu

    2010-01-01

    Full Text Available The mucosal surface of the female genital tract is a complex biosystem, which provides a barrier against the outside world and participates in both innate and acquired immune defense systems. This mucosal compartment has adapted to a dynamic, non-sterile environment challenged by a variety of antigenic/inflammatory stimuli associated with sexual intercourse and endogenous vaginal microbiota. Rapid innate immune defenses against microbial infection usually involve the recognition of invading pathogens by specific pattern-recognition receptors recently attributed to the family of Toll-like receptors (TLRs. TLRs recognize conserved pathogen-associated molecular patterns (PAMPs synthesized by microorganisms including bacteria, fungi, parasites, and viruses as well as endogenous ligands associated with cell damage. Members of the TLR family, which includes 10 human TLRs identified to date, recognize distinct PAMPs produced by various bacterial, fungal, and viral pathogens. The available literature regarding the innate immune system of the female genital tract during human reproductive processes was reviewed in order to identify studies specifically related to the expression and function of TLRs under normal as well as pathological conditions. Increased understanding of these molecules may provide insight into site-specific immunoregulatory mechanisms in the female reproductive tract.

  3. Crystal structures of the transcriptional repressor RolR reveals a novel recognition mechanism between inducer and regulator.

    Directory of Open Access Journals (Sweden)

    De-Feng Li

    Full Text Available Many members of the TetR family control the transcription of genes involved in multidrug resistance and pathogenicity. RolR (ResorcinolRegulator, the recently reported TetR-type regulator for aromatic catabolism from Corynebacterium glutamicum, distinguishes itself by low sequence similarities and different regulation from the previously known members of the TetR family. Here we report the crystal structures of RolR in its effector-bound (with resorcinol and aop- forms at 2.5 Å and 3.6 Å, respectively. The structure of resorcinol-RolR complex reveal that the hydrogen-bonded network mediated by the four-residue motif (Asp94- Arg145- Arg148- Asp149 with two water molecules and the hydrophobic interaction via five residues (Phe107, Leu111, Leu114, Leu142, and Phe172 are the key factors for the recognition and binding between the resorcinol and RolR molecules. The center-to-center separation of the recognition helices h3-h3' is decreased upon effector-binding from 34.9 Å to 30.4 Å. This structural change results in that RolR was unsuitable for DNA binding. Those observations are distinct from that in other TetR members. Structure-based mutagenesis on RolR was carried out and the results confirmed the critical roles of the above mentioned residues for effector-binding specificity and affinity. Similar sequence searches and sequence alignments identified 29 RolR homologues from GenBank, and all the above mentioned residues are highly conserved in the homologues. Based on these structural and other functional investigations, it is proposed that RolR may represent a new subfamily of TetR proteins that are invovled in aromatic degradation and sharing common recognition mode as for RolR.

  4. Recognition Strategies of Group 3 Innate Lymphoid Cells

    OpenAIRE

    Killig, Monica; Glatzer, Timor; Romagnani, Chiara

    2014-01-01

    During the early phase of an inflammatory response, innate cells can use different strategies to sense environmental danger. These include the direct interaction of specific activating receptors (actR) with pathogen-encoded/danger molecules or the engagement of cytokine receptors by pro-inflammatory mediators produced by antigen presenting cells (APC) in the course of the infection. These general recognition strategies, which have been extensively described for innate myeloid cells, are share...

  5. Supramolecular chemistry-general principles and selected examples from anion recognition and metallosupramolecular chemistry.

    Science.gov (United States)

    Albrecht, Markus

    2007-12-01

    This review gives an introduction into supramolecular chemistry describing in the first part general principles, focusing on terms like noncovalent interaction, molecular recognition, self-assembly, and supramolecular function. In the second part those will be illustrated by simple examples from our laboratories. Supramolecular chemistry is the science that bridges the gap between the world of molecules and nanotechnology. In supramolecular chemistry noncovalent interactions occur between molecular building blocks, which by molecular recognition and self-assembly form (functional) supramolecular entities. It is also termed the "chemistry of the noncovalent bond." Molecular recognition is based on geometrical complementarity based on the "key-and-lock" principle with nonshape-dependent effects, e.g., solvatization, being also highly influential. Self-assembly leads to the formation of well-defined aggregates. Hereby the overall structure of the target ensemble is controlled by the symmetry features of the certain building blocks. Finally, the aggregates can possess special properties or supramolecular functions, which are only found in the ensemble but not in the participating molecules. This review gives an introduction on supramolecular chemistry and illustrates the fundamental principles by recent examples from our group.

  6. Superexcited states of molecules

    International Nuclear Information System (INIS)

    Nakamura, Hiroki; Takagi, Hidekazu.

    1990-01-01

    The report addresses the nature and major features of molecule's superexcited states, focusing on their involvement in dynamic processes. It also outlines the quantum defect theory which allows various processes involving these states to be treated in a unified way. The Rydberg state has close relation with an ionized state with a positive energy. The quantum defect theory interprets such relation. Specifically, the report first describes the quantum defect theory focusing on its basic principle. The multi-channel quantum defect theory is then outlined centering on how to describe a Rydberg-type superexcited state. Description of a dissociative double-electron excited state is also discussed. The quantum defect theory is based on the fact that the physics of the motion of a Rydberg electron vary with the region in the electron's coordinate space. Finally, various molecular processes that involve a superexcited state are addressed focusing on autoionization, photoionization, dissociative recombination and bonding ionization of diatomic molecules. (N.K.)

  7. Simultaneous Binding of Hybrid Molecules Constructed with Dual DNA-Binding Components to a G-Quadruplex and Its Proximal Duplex.

    Science.gov (United States)

    Asamitsu, Sefan; Obata, Shunsuke; Phan, Anh Tuân; Hashiya, Kaori; Bando, Toshikazu; Sugiyama, Hiroshi

    2018-03-20

    A G-quadruplex (quadruplex) is a nucleic acid secondary structure adopted by guanine-rich sequences and is considered to be relevant to various pharmacological and biological contexts. Although a number of researchers have endeavored to discover and develop quadruplex-interactive molecules, poor ligand designability originating from topological similarity of the skeleton of diverse quadruplexes has remained a bottleneck for gaining specificity for individual quadruplexes. This work reports on hybrid molecules that were constructed with dual DNA-binding components, a cyclic imidazole/lysine polyamide (cIKP), and a hairpin pyrrole/imidazole polyamide (hPIP), with the aim toward specific quadruplex targeting by reading out the local duplex DNA sequence adjacent to designated quadruplexes in the genome. By means of circular dichroism (CD), fluorescence resonance energy transfer (FRET), surface plasmon resonance (SPR), and NMR techniques, we showed the dual and simultaneous recognition of the respective segment via hybrid molecules, and the synergistic and mutual effect of each binding component that was appropriately linked on higher binding affinity and modest sequence specificity. Monitoring quadruplex and duplex imino protons of the quadruplex/duplex motif titrated with hybrid molecules clearly revealed distinct features of the binding of hybrid molecules to the respective segments upon their simultaneous recognition. A series of the systematic and detailed binding assays described here showed that the concept of simultaneous recognition of quadruplex and its proximal duplex by hybrid molecules constructed with the dual DNA-binding components may provide a new strategy for ligand design, enabling targeting of a large variety of designated quadruplexes at specific genome locations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

    DEFF Research Database (Denmark)

    Klementiev, B; Novikova, T; Novitskaya, V

    2007-01-01

    death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

  9. On speech recognition during anaesthesia

    DEFF Research Database (Denmark)

    Alapetite, Alexandre

    2007-01-01

    This PhD thesis in human-computer interfaces (informatics) studies the case of the anaesthesia record used during medical operations and the possibility to supplement it with speech recognition facilities. Problems and limitations have been identified with the traditional paper-based anaesthesia...... and inaccuracies in the anaesthesia record. Supplementing the electronic anaesthesia record interface with speech input facilities is proposed as one possible solution to a part of the problem. The testing of the various hypotheses has involved the development of a prototype of an electronic anaesthesia record...... interface with speech input facilities in Danish. The evaluation of the new interface was carried out in a full-scale anaesthesia simulator. This has been complemented by laboratory experiments on several aspects of speech recognition for this type of use, e.g. the effects of noise on speech recognition...

  10. Simultaneous tracking and activity recognition

    DEFF Research Database (Denmark)

    Manfredotti, Cristina Elena; Fleet, David J.; Hamilton, Howard J.

    2011-01-01

    be used to improve the prediction step of the tracking, while, at the same time, tracking information can be used for online activity recognition. Experimental results in two different settings show that our approach 1) decreases the error rate and improves the identity maintenance of the positional......Many tracking problems involve several distinct objects interacting with each other. We develop a framework that takes into account interactions between objects allowing the recognition of complex activities. In contrast to classic approaches that consider distinct phases of tracking and activity...... tracking and 2) identifies the correct activity with higher accuracy than standard approaches....

  11. In Vitro Selection and Characterization of DNA Aptamers to a Small Molecule Target.

    Science.gov (United States)

    Ruscito, Annamaria; McConnell, Erin M; Koudrina, Anna; Velu, Ranganathan; Mattice, Christopher; Hunt, Vernon; McKeague, Maureen; DeRosa, Maria C

    2017-12-14

    Aptamers, synthetic oligonucleotide-based molecular recognition probes, have found use in a wide array of biosensing technologies based on their tight and highly selective binding to a variety of molecular targets. However, the inherent challenges associated with the selection and characterization of aptamers for small molecule targets have resulted in their underrepresentation, despite the need for small molecule detection in fields such as medicine, the environment, and agriculture. This protocol describes the steps in the selection, sequencing, affinity characterization, and truncation of DNA aptamers that are specific for small molecule targets. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  12. Eye movements during object recognition in visual agnosia.

    Science.gov (United States)

    Charles Leek, E; Patterson, Candy; Paul, Matthew A; Rafal, Robert; Cristino, Filipe

    2012-07-01

    This paper reports the first ever detailed study about eye movement patterns during single object recognition in visual agnosia. Eye movements were recorded in a patient with an integrative agnosic deficit during two recognition tasks: common object naming and novel object recognition memory. The patient showed normal directional biases in saccades and fixation dwell times in both tasks and was as likely as controls to fixate within object bounding contour regardless of recognition accuracy. In contrast, following initial saccades of similar amplitude to controls, the patient showed a bias for short saccades. In object naming, but not in recognition memory, the similarity of the spatial distributions of patient and control fixations was modulated by recognition accuracy. The study provides new evidence about how eye movements can be used to elucidate the functional impairments underlying object recognition deficits. We argue that the results reflect a breakdown in normal functional processes involved in the integration of shape information across object structure during the visual perception of shape. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Are olfactory cues involved in nest recognition in two social species of estrildid finches?

    Directory of Open Access Journals (Sweden)

    E Tobias Krause

    Full Text Available Reliably recognizing their own nest provides parents with a necessary skill to invest time and resources efficiently in raising their offspring and thereby maximising their own reproductive success. Studies investigating nest recognition in adult birds have focused mainly on visual cues of the nest or the nest site and acoustic cues of the nestlings. To determine whether adult songbirds also use olfaction for nest recognition, we investigated the use of olfactory nest cues for two estrildid finch species, zebra finches (Taeniopygia guttata and Bengalese finches (Lonchura striata var. domestica during the nestling and fledgling phase of their offspring. We found similar behavioural responses to nest odours in both songbird species. Females preferred the odour of their own nest over a control and avoided the foreign conspecific nest scent over a control during the nestling phase of their offspring, but when given the own odour and the foreign conspecific odour simultaneously we did not find a preference for the own nest odour. Males of both species did not show any preferences at all. The behavioural reaction to any nest odour decreased after fledging of the offspring. Our results show that only females show a behavioural response to olfactory nest cues, indicating that the use of olfactory cues for nest recognition seems to be sex-specific and dependent on the developmental stage of the offspring. Although estrildid finches are known to use visual and acoustic cues for nest recognition, the similar behavioural pattern of both species indicates that at least females gain additional information by olfactory nest cues during the nestling phase of their offspring. Thus olfactory cues might be important in general, even in situations in which visual and acoustic cues are known to be sufficient.

  14. Dissociation of alloantigen recognition from self major histocompatibility complex-restricted recognition of cytolytic T lymphocytes by monoclonal antireceptor antibodies

    International Nuclear Information System (INIS)

    Kanagawa, O.; Nagasawa, R.

    1987-01-01

    Two monoclonal antibodies (mAb) directed to the dual reactive cytolytic T lymphocyte clone OH8 (D/sup b/T H-Y and H-2/sup d/) were established. Analysis by cell surface staining and immunoprecipitation of radiolabeled surface molecules of OH8 followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis reveled that both mAb recognized an identical heterodimeric, clonotypic structure on OH8 cells, i.e., T cell receptor. However, although the MR3-2 mAb inhibited the lysis of either D/sup b/ + H-Y or H-2/sup d/ targets by OH8, the MR3-6 mAb inhibited the lysis of H-2/sup d/ target cells, but not that of D/sup b/ + H-Y target cells. Modulation of T cell receptor by either MR3-2 or MR3-6 mAb rendered the OH8 cytolytic T lyrphocyte incapable of killing both D/sup b/ + H-Y and H-2/sup d/ target cells. These finding suggest that different epitopes of OH8 T cell receptor were involved for the recognition of self + antigen and alloantigen

  15. Identities of P2 and P3 Residues of H-2Kb-Bound Peptides Determine Mouse Ly49C Recognition.

    Directory of Open Access Journals (Sweden)

    Elsa A Marquez

    Full Text Available Ly49 receptors can be peptide selective in their recognition of MHC-I-peptide complexes, affording them a level of discrimination beyond detecting the presence or absence of specific MHC-I allele products. Despite this ability, little is understood regarding the properties that enable some peptides, when bound to MHC-I molecules, to support Ly49 recognition, but not others. Using RMA-S target cells expressing MHC-I molecules loaded with individual peptides and effector cells expressing the ectodomain of the inhibitory Ly49C receptor, we found that two adjacent amino acid residues, P2 and P3, both buried in the peptide binding groove of H-2Kb, determine mouse Ly49C specificity. If both are aliphatic residues, this is supportive. Whereas, small amino acids at P2 and aromatic amino acids at the P3 auxiliary anchor residue are detrimental to Ly49C recognition. These results resemble those with a rat Ly49 where the identity of a peptide anchor residue determines recognition, suggesting that dependence on specific peptide residues buried in the MHC-I peptide-binding groove may be fundamental to Ly49 peptide selectivity and recognition.

  16. Mechanisms of Expression and Internalisation of FIBCD1; a novel Pattern Recognition Receptor in the Gut Mucosa

    DEFF Research Database (Denmark)

    Hammond, Mark; Schlosser, Anders; Dubey, Lalit Kumar

    2012-01-01

    is a carbohydrate recognition domain also expressed by the ficolins, which are pattern recognition molecules that activate the complement system via the lectin pathway. Chitin is a highly ace¬tylated homopolymer of β-1,4-N-acetyl-glucosamine carbohydrate found abundantly in nature in organisms such as fungi...... pattern recognition receptor that binds chitin and directs acetylated structures for de¬gradation in the endosome via clathrin-mediated endocytosis. The localisation of FIBCD1 in the intestinal mucosal epithelia points towards a functional role in innate immunity and/or gut homeostasis....

  17. Normal mere exposure effect with impaired recognition in Alzheimer's disease.

    Science.gov (United States)

    Willems, Sylvie; Adam, Stéphane; Van der Linden, Martial

    2002-02-01

    We investigated the mere exposure effect and the explicit memory in Alzheimer's disease (AD) patients and elderly control subjects, using unfamiliar faces. During the exposure phase, the subjects estimated the age of briefly flashed faces. The mere exposure effect was examined by presenting pairs of faces (old and new) and asking participants to select the face they liked. The participants were then presented with a forced-choice explicit recognition task. Controls subjects exhibited above-chance preference and recognition scores for old faces. The AD patients also showed the mere exposure effect but no explicit recognition. These results suggest that the processes involved in the mere exposure effect are preserved in AD patients despite their impaired explicit recognition. The results are discussed in terms of Seamon et al.'s (1995) proposal that processes involved in the mere exposure effect are equivalent to those subserving perceptual priming. These processes would depend on extrastriate areas which are relatively preserved in AD patients.

  18. What pharmacological interventions indicate concerning the role of the perirhinal cortex in recognition memory.

    Science.gov (United States)

    Brown, M W; Barker, G R I; Aggleton, J P; Warburton, E C

    2012-11-01

    Findings of pharmacological studies that have investigated the involvement of specific regions of the brain in recognition memory are reviewed. The particular emphasis of the review concerns what such studies indicate concerning the role of the perirhinal cortex in recognition memory. Most of the studies involve rats and most have investigated recognition memory for objects. Pharmacological studies provide a large body of evidence supporting the essential role of the perirhinal cortex in the acquisition, consolidation and retrieval of object recognition memory. Such studies provide increasingly detailed evidence concerning both the neurotransmitter systems and the underlying intracellular mechanisms involved in recognition memory processes. They have provided evidence in support of synaptic weakening as a major synaptic plastic process within perirhinal cortex underlying object recognition memory. They have also supplied confirmatory evidence that that there is more than one synaptic plastic process involved. The demonstrated necessity to long-term recognition memory of intracellular signalling mechanisms related to synaptic modification within perirhinal cortex establishes a central role for the region in the information storage underlying such memory. Perirhinal cortex is thereby established as an information storage site rather than solely a processing station. Pharmacological studies have also supplied new evidence concerning the detailed roles of other regions, including the hippocampus and the medial prefrontal cortex in different types of recognition memory tasks that include a spatial or temporal component. In so doing, they have also further defined the contribution of perirhinal cortex to such tasks. To date it appears that the contribution of perirhinal cortex to associative and temporal order memory reflects that in simple object recognition memory, namely that perirhinal cortex provides information concerning objects and their prior occurrence (novelty

  19. Bilingual Language Switching: Production vs. Recognition

    Science.gov (United States)

    Mosca, Michela; de Bot, Kees

    2017-01-01

    This study aims at assessing how bilinguals select words in the appropriate language in production and recognition while minimizing interference from the non-appropriate language. Two prominent models are considered which assume that when one language is in use, the other is suppressed. The Inhibitory Control (IC) model suggests that, in both production and recognition, the amount of inhibition on the non-target language is greater for the stronger compared to the weaker language. In contrast, the Bilingual Interactive Activation (BIA) model proposes that, in language recognition, the amount of inhibition on the weaker language is stronger than otherwise. To investigate whether bilingual language production and recognition can be accounted for by a single model of bilingual processing, we tested a group of native speakers of Dutch (L1), advanced speakers of English (L2) in a bilingual recognition and production task. Specifically, language switching costs were measured while participants performed a lexical decision (recognition) and a picture naming (production) task involving language switching. Results suggest that while in language recognition the amount of inhibition applied to the non-appropriate language increases along with its dominance as predicted by the IC model, in production the amount of inhibition applied to the non-relevant language is not related to language dominance, but rather it may be modulated by speakers' unconscious strategies to foster the weaker language. This difference indicates that bilingual language recognition and production might rely on different processing mechanisms and cannot be accounted within one of the existing models of bilingual language processing. PMID:28638361

  20. Do people have insight into their face recognition abilities?

    Science.gov (United States)

    Palermo, Romina; Rossion, Bruno; Rhodes, Gillian; Laguesse, Renaud; Tez, Tolga; Hall, Bronwyn; Albonico, Andrea; Malaspina, Manuela; Daini, Roberta; Irons, Jessica; Al-Janabi, Shahd; Taylor, Libby C; Rivolta, Davide; McKone, Elinor

    2017-02-01

    Diagnosis of developmental or congenital prosopagnosia (CP) involves self-report of everyday face recognition difficulties, which are corroborated with poor performance on behavioural tests. This approach requires accurate self-evaluation. We examine the extent to which typical adults have insight into their face recognition abilities across four experiments involving nearly 300 participants. The experiments used five tests of face recognition ability: two that tap into the ability to learn and recognize previously unfamiliar faces [the Cambridge Face Memory Test, CFMT; Duchaine, B., & Nakayama, K. (2006). The Cambridge Face Memory Test: Results for neurologically intact individuals and an investigation of its validity using inverted face stimuli and prosopagnosic participants. Neuropsychologia, 44(4), 576-585. doi:10.1016/j.neuropsychologia.2005.07.001; and a newly devised test based on the CFMT but where the study phases involve watching short movies rather than viewing static faces-the CFMT-Films] and three that tap face matching [Benton Facial Recognition Test, BFRT; Benton, A., Sivan, A., Hamsher, K., Varney, N., & Spreen, O. (1983). Contribution to neuropsychological assessment. New York: Oxford University Press; and two recently devised sequential face matching tests]. Self-reported ability was measured with the 15-item Kennerknecht et al. questionnaire [Kennerknecht, I., Ho, N. Y., & Wong, V. C. (2008). Prevalence of hereditary prosopagnosia (HPA) in Hong Kong Chinese population. American Journal of Medical Genetics Part A, 146A(22), 2863-2870. doi:10.1002/ajmg.a.32552]; two single-item questions assessing face recognition ability; and a new 77-item meta-cognition questionnaire. Overall, we find that adults with typical face recognition abilities have only modest insight into their ability to recognize faces on behavioural tests. In a fifth experiment, we assess self-reported face recognition ability in people with CP and find that some people who expect to

  1. L2 Word Recognition: Influence of L1 Orthography on Multi-syllabic Word Recognition.

    Science.gov (United States)

    Hamada, Megumi

    2017-10-01

    L2 reading research suggests that L1 orthographic experience influences L2 word recognition. Nevertheless, the findings on multi-syllabic words in English are still limited despite the fact that a vast majority of words are multi-syllabic. The study investigated whether L1 orthography influences the recognition of multi-syllabic words, focusing on the position of an embedded word. The participants were Arabic ESL learners, Chinese ESL learners, and native speakers of English. The task was a word search task, in which the participants identified a target word embedded in a pseudoword at the initial, middle, or final position. The search accuracy and speed indicated that all groups showed a strong preference for the initial position. The accuracy data further indicated group differences. The Arabic group showed higher accuracy in the final than middle, while the Chinese group showed the opposite and the native speakers showed no difference between the two positions. The findings suggest that L2 multi-syllabic word recognition involves unique processes.

  2. Atomic force microscopy imaging and single molecule recognition force spectroscopy of coat proteins on the surface of Bacillus subtilis spore.

    Science.gov (United States)

    Tang, Jilin; Krajcikova, Daniela; Zhu, Rong; Ebner, Andreas; Cutting, Simon; Gruber, Hermann J; Barak, Imrich; Hinterdorfer, Peter

    2007-01-01

    Coat assembly in Bacillus subtilis serves as a tractable model for the study of the self-assembly process of biological structures and has a significant potential for use in nano-biotechnological applications. In the present study, the morphology of B. subtilis spores was investigated by magnetically driven dynamic force microscopy (MAC mode atomic force microscopy) under physiological conditions. B. subtilis spores appeared as prolate structures, with a length of 0.6-3 microm and a width of about 0.5-2 microm. The spore surface was mainly covered with bump-like structures with diameters ranging from 8 to 70 nm. Besides topographical explorations, single molecule recognition force spectroscopy (SMRFS) was used to characterize the spore coat protein CotA. This protein was specifically recognized by a polyclonal antibody directed against CotA (anti-CotA), the antibody being covalently tethered to the AFM tip via a polyethylene glycol linker. The unbinding force between CotA and anti-CotA was determined as 55 +/- 2 pN. From the high-binding probability of more than 20% in force-distance cycles it is concluded that CotA locates in the outer surface of B. subtilis spores. Copyright (c) 2007 John Wiley & Sons, Ltd.

  3. Stimulation over primary motor cortex during action observation impairs effector recognition.

    Science.gov (United States)

    Naish, Katherine R; Barnes, Brittany; Obhi, Sukhvinder S

    2016-04-01

    Recent work suggests that motor cortical processing during action observation plays a role in later recognition of the object involved in the action. Here, we investigated whether recognition of the effector making an action is also impaired when transcranial magnetic stimulation (TMS) - thought to interfere with normal cortical activity - is applied over the primary motor cortex (M1) during action observation. In two experiments, single-pulse TMS was delivered over the hand area of M1 while participants watched short clips of hand actions. Participants were then asked whether an image (experiment 1) or a video (experiment 2) of a hand presented later in the trial was the same or different to the hand in the preceding video. In Experiment 1, we found that participants' ability to recognise static images of hands was significantly impaired when TMS was delivered over M1 during action observation, compared to when no TMS was delivered, or when stimulation was applied over the vertex. Conversely, stimulation over M1 did not affect recognition of dot configurations, or recognition of hands that were previously presented as static images (rather than action movie clips) with no object. In Experiment 2, we found that effector recognition was impaired when stimulation was applied part way through (300ms) and at the end (500ms) of the action observation period, indicating that 200ms of action-viewing following stimulation was not long enough to form a new representation that could be used for later recognition. The findings of both experiments suggest that interfering with cortical motor activity during action observation impairs subsequent recognition of the effector involved in the action, which complements previous findings of motor system involvement in object memory. This work provides some of the first evidence that motor processing during action observation is involved in forming representations of the effector that are useful beyond the action observation period

  4. Further dissociating the processes involved in recognition memory: an FMRI study.

    Science.gov (United States)

    Henson, Richard N A; Hornberger, Michael; Rugg, Michael D

    2005-07-01

    Based on an event-related potential study by Rugg et al. [Dissociation of the neural correlates of implicit and explicit memory. Nature, 392, 595-598, 1998], we attempted to isolate the hemodynamic correlates of recollection, familiarity, and implicit memory within a single verbal recognition memory task using event-related fMRI. Words were randomly cued for either deep or shallow processing, and then intermixed with new words for yes/no recognition. The number of studied words was such that, whereas most were recognized ("hits"), an appreciable number of shallow-studied words were not ("misses"). Comparison of deep hits versus shallow hits at test revealed activations in regions including the left inferior parietal gyrus. Comparison of shallow hits versus shallow misses revealed activations in regions including the bilateral intraparietal sulci, the left posterior middle frontal gyrus, and the left frontopolar cortex. Comparison of hits versus correct rejections revealed a relative deactivation in an anterior left medial-temporal region (most likely the perirhinal cortex). Comparison of shallow misses versus correct rejections did not reveal response decreases in any regions expected on the basis of previous imaging studies of priming. Given these and previous data, we associate the left inferior parietal activation with recollection, the left anterior medial-temporal deactivation with familiarity, and the intraparietal and prefrontal responses with target detection. The absence of differences between shallow misses and correct rejections means that the hemodynamic correlates of implicit memory remain unclear.

  5. Single-Molecule Interfacial Electron Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Lu, H. Peter [Bowling Green State Univ., Bowling Green, OH (United States). Dept. of Chemistry and Center for Photochemical Sciences

    2017-11-28

    This project is focused on the use of single-molecule high spatial and temporal resolved techniques to study molecular dynamics in condensed phase and at interfaces, especially, the complex reaction dynamics associated with electron and energy transfer rate processes. The complexity and inhomogeneity of the interfacial ET dynamics often present a major challenge for a molecular level comprehension of the intrinsically complex systems, which calls for both higher spatial and temporal resolutions at ultimate single-molecule and single-particle sensitivities. Combined single-molecule spectroscopy and electrochemical atomic force microscopy approaches are unique for heterogeneous and complex interfacial electron transfer systems because the static and dynamic inhomogeneities can be identified and characterized by studying one molecule at a specific nanoscale surface site at a time. The goal of our project is to integrate and apply these spectroscopic imaging and topographic scanning techniques to measure the energy flow and electron flow between molecules and substrate surfaces as a function of surface site geometry and molecular structure. We have been primarily focusing on studying interfacial electron transfer under ambient condition and electrolyte solution involving both single crystal and colloidal TiO2 and related substrates. The resulting molecular level understanding of the fundamental interfacial electron transfer processes will be important for developing efficient light harvesting systems and broadly applicable to problems in fundamental chemistry and physics. We have made significant advancement on deciphering the underlying mechanism of the complex and inhomogeneous interfacial electron transfer dynamics in dyesensitized TiO2 nanoparticle systems that strongly involves with and regulated by molecule-surface interactions. We have studied interfacial electron transfer on TiO2 nanoparticle surfaces by using ultrafast single-molecule

  6. Molecular Wring Resonances in Chain Molecules

    DEFF Research Database (Denmark)

    Bohr, Henrik; Brunak, Søren; Bohr, Jakob

    1997-01-01

    It is shown that the eigenfrequency of collective twist excitations in chain molecules can be in the megahertz and gigahertz range. Accordingly, resonance states can be obtained at specific frequencies, and phenomena that involve structural properties can take place. Chain molecules can alter the...... their conformation and their ability to function, and a breaking of the chain can result. It is suggested that this phenomenon forms the basis for effects caused by the interaction of microwaves and biomolecules, e.g. microwave assisted hydrolysis of chain molecules....

  7. Visual face-movement sensitive cortex is relevant for auditory-only speech recognition.

    Science.gov (United States)

    Riedel, Philipp; Ragert, Patrick; Schelinski, Stefanie; Kiebel, Stefan J; von Kriegstein, Katharina

    2015-07-01

    It is commonly assumed that the recruitment of visual areas during audition is not relevant for performing auditory tasks ('auditory-only view'). According to an alternative view, however, the recruitment of visual cortices is thought to optimize auditory-only task performance ('auditory-visual view'). This alternative view is based on functional magnetic resonance imaging (fMRI) studies. These studies have shown, for example, that even if there is only auditory input available, face-movement sensitive areas within the posterior superior temporal sulcus (pSTS) are involved in understanding what is said (auditory-only speech recognition). This is particularly the case when speakers are known audio-visually, that is, after brief voice-face learning. Here we tested whether the left pSTS involvement is causally related to performance in auditory-only speech recognition when speakers are known by face. To test this hypothesis, we applied cathodal transcranial direct current stimulation (tDCS) to the pSTS during (i) visual-only speech recognition of a speaker known only visually to participants and (ii) auditory-only speech recognition of speakers they learned by voice and face. We defined the cathode as active electrode to down-regulate cortical excitability by hyperpolarization of neurons. tDCS to the pSTS interfered with visual-only speech recognition performance compared to a control group without pSTS stimulation (tDCS to BA6/44 or sham). Critically, compared to controls, pSTS stimulation additionally decreased auditory-only speech recognition performance selectively for voice-face learned speakers. These results are important in two ways. First, they provide direct evidence that the pSTS is causally involved in visual-only speech recognition; this confirms a long-standing prediction of current face-processing models. Secondly, they show that visual face-sensitive pSTS is causally involved in optimizing auditory-only speech recognition. These results are in line

  8. Recall and recognition hypermnesia for Socratic stimuli.

    Science.gov (United States)

    Kazén, Miguel; Solís-Macías, Víctor M

    2016-01-01

    In two experiments, we investigate hypermnesia, net memory improvements with repeated testing of the same material after a single study trial. In the first experiment, we found hypermnesia across three trials for the recall of word solutions to Socratic stimuli (dictionary-like definitions of concepts) replicating Erdelyi, Buschke, and Finkelstein and, for the first time using these materials, for their recognition. In the second experiment, we had two "yes/no" recognition groups, a Socratic stimuli group presented with concrete and abstract verbal materials and a word-only control group. Using signal detection measures, we found hypermnesia for concrete Socratic stimuli-and stable performance for abstract stimuli across three recognition tests. The control group showed memory decrements across tests. We interpret these findings with the alternative retrieval pathways (ARP) hypothesis, contrasting it with alternative theories of hypermnesia, such as depth of processing, generation and retrieve-recognise. We conclude that recognition hypermnesia for concrete Socratic stimuli is a reliable phenomenon, which we found in two experiments involving both forced-choice and yes/no recognition procedures.

  9. Experiments on Automatic Recognition of Nonnative Arabic Speech

    Directory of Open Access Journals (Sweden)

    Douglas O'Shaughnessy

    2008-05-01

    Full Text Available The automatic recognition of foreign-accented Arabic speech is a challenging task since it involves a large number of nonnative accents. As well, the nonnative speech data available for training are generally insufficient. Moreover, as compared to other languages, the Arabic language has sparked a relatively small number of research efforts. In this paper, we are concerned with the problem of nonnative speech in a speaker independent, large-vocabulary speech recognition system for modern standard Arabic (MSA. We analyze some major differences at the phonetic level in order to determine which phonemes have a significant part in the recognition performance for both native and nonnative speakers. Special attention is given to specific Arabic phonemes. The performance of an HMM-based Arabic speech recognition system is analyzed with respect to speaker gender and its native origin. The WestPoint modern standard Arabic database from the language data consortium (LDC and the hidden Markov Model Toolkit (HTK are used throughout all experiments. Our study shows that the best performance in the overall phoneme recognition is obtained when nonnative speakers are involved in both training and testing phases. This is not the case when a language model and phonetic lattice networks are incorporated in the system. At the phonetic level, the results show that female nonnative speakers perform better than nonnative male speakers, and that emphatic phonemes yield a significant decrease in performance when they are uttered by both male and female nonnative speakers.

  10. Experiments on Automatic Recognition of Nonnative Arabic Speech

    Directory of Open Access Journals (Sweden)

    Selouani Sid-Ahmed

    2008-01-01

    Full Text Available The automatic recognition of foreign-accented Arabic speech is a challenging task since it involves a large number of nonnative accents. As well, the nonnative speech data available for training are generally insufficient. Moreover, as compared to other languages, the Arabic language has sparked a relatively small number of research efforts. In this paper, we are concerned with the problem of nonnative speech in a speaker independent, large-vocabulary speech recognition system for modern standard Arabic (MSA. We analyze some major differences at the phonetic level in order to determine which phonemes have a significant part in the recognition performance for both native and nonnative speakers. Special attention is given to specific Arabic phonemes. The performance of an HMM-based Arabic speech recognition system is analyzed with respect to speaker gender and its native origin. The WestPoint modern standard Arabic database from the language data consortium (LDC and the hidden Markov Model Toolkit (HTK are used throughout all experiments. Our study shows that the best performance in the overall phoneme recognition is obtained when nonnative speakers are involved in both training and testing phases. This is not the case when a language model and phonetic lattice networks are incorporated in the system. At the phonetic level, the results show that female nonnative speakers perform better than nonnative male speakers, and that emphatic phonemes yield a significant decrease in performance when they are uttered by both male and female nonnative speakers.

  11. 8 CFR 1292.2 - Organizations qualified for recognition; requests for recognition; withdrawal of recognition...

    Science.gov (United States)

    2010-01-01

    ...; requests for recognition; withdrawal of recognition; accreditation of representatives; roster. 1292.2...; requests for recognition; withdrawal of recognition; accreditation of representatives; roster. (a) Qualifications of organizations. A non-profit religious, charitable, social service, or similar organization...

  12. [Face recognition in patients with autism spectrum disorders].

    Science.gov (United States)

    Kita, Yosuke; Inagaki, Masumi

    2012-07-01

    The present study aimed to review previous research conducted on face recognition in patients with autism spectrum disorders (ASD). Face recognition is a key question in the ASD research field because it can provide clues for elucidating the neural substrates responsible for the social impairment of these patients. Historically, behavioral studies have reported low performance and/or unique strategies of face recognition among ASD patients. However, the performance and strategy of ASD patients is comparable to those of the control group, depending on the experimental situation or developmental stage, suggesting that face recognition of ASD patients is not entirely impaired. Recent brain function studies, including event-related potential and functional magnetic resonance imaging studies, have investigated the cognitive process of face recognition in ASD patients, and revealed impaired function in the brain's neural network comprising the fusiform gyrus and amygdala. This impaired function is potentially involved in the diminished preference for faces, and in the atypical development of face recognition, eliciting symptoms of unstable behavioral characteristics in these patients. Additionally, face recognition in ASD patients is examined from a different perspective, namely self-face recognition, and facial emotion recognition. While the former topic is intimately linked to basic social abilities such as self-other discrimination, the latter is closely associated with mentalizing. Further research on face recognition in ASD patients should investigate the connection between behavioral and neurological specifics in these patients, by considering developmental changes and the spectrum clinical condition of ASD.

  13. Threshold models of recognition and the recognition heuristic

    Directory of Open Access Journals (Sweden)

    Edgar Erdfelder

    2011-02-01

    Full Text Available According to the recognition heuristic (RH theory, decisions follow the recognition principle: Given a high validity of the recognition cue, people should prefer recognized choice options compared to unrecognized ones. Assuming that the memory strength of choice options is strongly correlated with both the choice criterion and recognition judgments, the RH is a reasonable strategy that approximates optimal decisions with a minimum of cognitive effort (Davis-Stober, Dana, and Budescu, 2010. However, theories of recognition memory are not generally compatible with this assumption. For example, some threshold models of recognition presume that recognition judgments can arise from two types of cognitive states: (1 certainty states in which judgments are almost perfectly correlated with memory strength and (2 uncertainty states in which recognition judgments reflect guessing rather than differences in memory strength. We report an experiment designed to test the prediction that the RH applies to certainty states only. Our results show that memory states rather than recognition judgments affect use of recognition information in binary decisions.

  14. Challenges for single molecule electronic devices with nanographene and organic molecules. Do single molecules offer potential as elements of electronic devices in the next generation?

    Science.gov (United States)

    Enoki, Toshiaki; Kiguchi, Manabu

    2018-03-01

    Interest in utilizing organic molecules to fabricate electronic materials has existed ever since organic (molecular) semiconductors were first discovered in the 1950s. Since then, scientists have devoted serious effort to the creation of various molecule-based electronic systems, such as molecular metals and molecular superconductors. Single-molecule electronics and the associated basic science have emerged over the past two decades and provided hope for the development of highly integrated molecule-based electronic devices in the future (after the Si-based technology era has ended). Here, nanographenes (nano-sized graphene) with atomically precise structures are among the most promising molecules that can be utilized for electronic/spintronic devices. To manipulate single small molecules for an electronic device, a single molecular junction has been developed. It is a powerful tool that allows even small molecules to be utilized. External electric, magnetic, chemical, and mechanical perturbations can change the physical and chemical properties of molecules in a way that is different from bulk materials. Therefore, the various functionalities of molecules, along with changes induced by external perturbations, allows us to create electronic devices that we cannot create using current top-down Si-based technology. Future challenges that involve the incorporation of condensed matter physics, quantum chemistry calculations, organic synthetic chemistry, and electronic device engineering are expected to open a new era in single-molecule device electronic technology.

  15. Transfer Learning for Rodent Behavior Recognition

    NARCIS (Netherlands)

    Lorbach, M.T.; Poppe, R.W.; van Dam, Elsbeth; Veltkamp, R.C.; Noldus, Lucas

    2016-01-01

    Many behavior recognition systems are trained and tested on single datasets limiting their application to comparable datasets. While retraining the system with a novel dataset is possible, it involves laborious annotation effort. We propose to minimize the annotation effort by reusing the knowledge

  16. Nest marking behavior and chemical composition of olfactory cues involved in nest recognition in Megachile rotundata.

    Science.gov (United States)

    Guédot, Christelle; Buckner, James S; Hagen, Marcia M; Bosch, Jordi; Kemp, William P; Pitts-Singer, Theresa L

    2013-08-01

    In-nest observations of the solitary bee, Megachile rotundata (F.), revealed that nesting females apply olfactory cues to nests for nest recognition. On their way in and out of the nest, females drag the abdomen along the entire length of the nest, and sometimes deposit fluid droplets from the tip of the abdomen. The removal of bee-marked sections of the nest resulted in hesitation and searching behavior by females, indicating the loss of olfactory cues used for nest recognition. Chemical analysis of female cuticles and the deposits inside marked nesting tubes revealed the presence of hydrocarbons, wax esters, fatty aldehydes, and fatty alcohol acetate esters. Chemical compositions were similar across tube samples, but proportionally different from cuticular extracts. These findings reveal the importance of lipids as chemical signals for nest recognition and suggest that the nest-marking cues are derived from a source in addition to, or other than, the female cuticle.

  17. A neuroanatomical predictor of mirror self-recognition in chimpanzees.

    Science.gov (United States)

    Hecht, E E; Mahovetz, L M; Preuss, T M; Hopkins, W D

    2017-01-01

    The ability to recognize one's own reflection is shared by humans and only a few other species, including chimpanzees. However, this ability is highly variable across individual chimpanzees. In humans, self-recognition involves a distributed, right-lateralized network including frontal and parietal regions involved in the production and perception of action. The superior longitudinal fasciculus (SLF) is a system of white matter tracts linking these frontal and parietal regions. The current study measured mirror self-recognition (MSR) and SLF anatomy in 60 chimpanzees using diffusion tensor imaging. Successful self-recognition was associated with greater rightward asymmetry in the white matter of SLFII and SLFIII, and in SLFIII's gray matter terminations in Broca's area. We observed a visible progression of SLFIII's prefrontal extension in apes that show negative, ambiguous, and compelling evidence of MSR. Notably, SLFIII's terminations in Broca's area are not right-lateralized or particularly pronounced at the population level in chimpanzees, as they are in humans. Thus, chimpanzees with more human-like behavior show more human-like SLFIII connectivity. These results suggest that self-recognition may have co-emerged with adaptations to frontoparietal circuitry. © The Author (2016). Published by Oxford University Press.

  18. Incorporating Duration Information in Activity Recognition

    Science.gov (United States)

    Chaurasia, Priyanka; Scotney, Bryan; McClean, Sally; Zhang, Shuai; Nugent, Chris

    Activity recognition has become a key issue in smart home environments. The problem involves learning high level activities from low level sensor data. Activity recognition can depend on several variables; one such variable is duration of engagement with sensorised items or duration of intervals between sensor activations that can provide useful information about personal behaviour. In this paper a probabilistic learning algorithm is proposed that incorporates episode, time and duration information to determine inhabitant identity and the activity being undertaken from low level sensor data. Our results verify that incorporating duration information consistently improves the accuracy.

  19. Synergy between ficolin-2 and pentraxin 3 boosts innate immune recognition and complement deposition

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Doni, Andrea; Hummelshøj, Tina

    2009-01-01

    The long pentraxin 3 (PTX3) is a multifunctional soluble pattern recognition molecule that is crucial in innate immune protection against opportunistic fungal pathogens such as Aspergillus fumigatus. The mechanisms that mediate downstream effects of PTX3 are largely unknown. However, PTX3 interac...

  20. Stage-specific sampling by pattern recognition receptors during Candida albicans phagocytosis.

    Directory of Open Access Journals (Sweden)

    Sigrid E M Heinsbroek

    2008-11-01

    Full Text Available Candida albicans is a medically important pathogen, and recognition by innate immune cells is critical for its clearance. Although a number of pattern recognition receptors have been shown to be involved in recognition and phagocytosis of this fungus, the relative role of these receptors has not been formally examined. In this paper, we have investigated the contribution of the mannose receptor, Dectin-1, and complement receptor 3; and we have demonstrated that Dectin-1 is the main non-opsonic receptor involved in fungal uptake. However, both Dectin-1 and complement receptor 3 were found to accumulate at the site of uptake, while mannose receptor accumulated on C. albicans phagosomes at later stages. These results suggest a potential role for MR in phagosome sampling; and, accordingly, MR deficiency led to a reduction in TNF-alpha and MCP-1 production in response to C. albicans uptake. Our data suggest that pattern recognition receptors sample the fungal phagosome in a sequential fashion.

  1. On the Several Molecules and Nanostructures of Water

    Directory of Open Access Journals (Sweden)

    Cynthia Kolb Whitney

    2012-01-01

    Full Text Available This paper investigates the water molecule from a variety of viewpoints. Water can involve different isotopes of Hydrogen and Oxygen, it can form differently shaped isomer molecules, and, when frozen, it occupies space differently than most other substances do. The tool for conducting the investigation of all this is called ‘Algebraic Chemistry’. This tool is a quantitative model for predicting the energy budget for all sorts of changes between different ionization states of atoms that are involved in chemical reactions and in changes of physical state. The model is based on consistent patterns seen in empirical data about ionization potentials, together with rational scaling laws that can interpolate and extrapolate for situations where no data are available. The results of the investigation of the water molecule include comments, both positive and negative, about technologies involving heavy water, poly water, Brown’s gas, and cold fusion.

  2. Nanoparticle-Based Receptors Mimic Protein-Ligand Recognition.

    Science.gov (United States)

    Riccardi, Laura; Gabrielli, Luca; Sun, Xiaohuan; De Biasi, Federico; Rastrelli, Federico; Mancin, Fabrizio; De Vivo, Marco

    2017-07-13

    The self-assembly of a monolayer of ligands on the surface of noble-metal nanoparticles dictates the fundamental nanoparticle's behavior and its functionality. In this combined computational-experimental study, we analyze the structure, organization, and dynamics of functionalized coating thiols in monolayer-protected gold nanoparticles (AuNPs). We explain how functionalized coating thiols self-organize through a delicate and somehow counterintuitive balance of interactions within the monolayer itself and with the solvent. We further describe how the nature and plasticity of these interactions modulate nanoparticle-based chemosensing. Importantly, we found that self-organization of coating thiols can induce the formation of binding pockets in AuNPs. These transient cavities can accommodate small molecules, mimicking protein-ligand recognition, which could explain the selectivity and sensitivity observed for different organic analytes in NMR chemosensing experiments. Thus, our findings advocate for the rational design of tailored coating groups to form specific recognition binding sites on monolayer-protected AuNPs.

  3. Stages of Processing in Associative Recognition : Evidence from Behavior, EEG, and Classification

    NARCIS (Netherlands)

    Borst, Jelmer P.; Schneider, Darryl W.; Walsh, Matthew M.; Anderson, John R.

    2013-01-01

    In this study, we investigated the stages of information processing in associative recognition. We recorded EEG data while participants performed an associative recognition task that involved manipulations of word length, associative fan, and probe type, which were hypothesized to affect the

  4. The neural correlates of visual self-recognition.

    Science.gov (United States)

    Devue, Christel; Brédart, Serge

    2011-03-01

    This paper presents a review of studies that were aimed at determining which brain regions are recruited during visual self-recognition, with a particular focus on self-face recognition. A complex bilateral network, involving frontal, parietal and occipital areas, appears to be associated with self-face recognition, with a particularly high implication of the right hemisphere. Results indicate that it remains difficult to determine which specific cognitive operation is reflected by each recruited brain area, in part due to the variability of used control stimuli and experimental tasks. A synthesis of the interpretations provided by previous studies is presented. The relevance of using self-recognition as an indicator of self-awareness is discussed. We argue that a major aim of future research in the field should be to identify more clearly the cognitive operations induced by the perception of the self-face, and search for dissociations between neural correlates and cognitive components. Copyright © 2010 Elsevier Inc. All rights reserved.

  5. Stigma-pollen recognition: a new look

    Directory of Open Access Journals (Sweden)

    C. Dumas

    2014-01-01

    Full Text Available During the last two decades, there have been several conceptual developments in our understanding of pollen-stigma recognition and molecular mechanisms involved. The main models proposed are compared. Based on additional data a hypothesis to complete these models especially for pollen hydration and adhesion is proposed. After attachment of the pollen to the stigma surface a close interaction exists involving lipoproteic membrane-like compounds (pollenkitt and stigma pellicle and pollen agglutinating ability.

  6. Human-assisted sound event recognition for home service robots.

    Science.gov (United States)

    Do, Ha Manh; Sheng, Weihua; Liu, Meiqin

    This paper proposes and implements an open framework of active auditory learning for a home service robot to serve the elderly living alone at home. The framework was developed to realize the various auditory perception capabilities while enabling a remote human operator to involve in the sound event recognition process for elderly care. The home service robot is able to estimate the sound source position and collaborate with the human operator in sound event recognition while protecting the privacy of the elderly. Our experimental results validated the proposed framework and evaluated auditory perception capabilities and human-robot collaboration in sound event recognition.

  7. HLA-E-Restricted Cross-Recognition of Allogeneic Endothelial Cells by CMV-Associated CD8 T Cells: A Potential Risk Factor following Transplantation

    Science.gov (United States)

    Allard, Mathilde; Tonnerre, Pierre; Nedellec, Steven; Oger, Romain; Morice, Alexis; Guilloux, Yannick; Houssaint, Elisabeth; Charreau, Béatrice; Gervois, Nadine

    2012-01-01

    Although association between CMV infection and allograft rejection is well admitted, the precise mechanisms involved remain uncertain. Here, we report the characterization of an alloreactive HLA-E-restricted CD8 T cell population that was detected in the PBL of a kidney transplant patient after its CMV conversion. This monoclonal CD8 T cell population represents a sizable fraction in the blood (3% of PBL) and is characterized by an effector-memory phenotype and the expression of multiple NK receptors. Interestingly, these unconventional T cells display HLA-E-dependent reactivity against peptides derived from the leader sequences of both various HCMV-UL40 and allogeneic classical HLA-I molecules. Consequently, while HLA-E-restricted CD8 T cells have potential to contribute to the control of CMV infection in vivo, they may also directly mediate graft rejection through recognition of peptides derived from allogeneic HLA-I molecules on graft cells. Therefore, as HLA-E expression in nonlymphoid organs is mainly restricted to endothelial cells, we investigated the reactivity of this HLA-E-restricted T cell population towards allogeneic endothelial cells. We clearly demonstrated that CMV-associated HLA-E-restricted T cells efficiently recognized and killed allogeneic endothelial cells in vitro. Moreover, our data indicate that this alloreactivity is tightly regulated by NK receptors, especially by inhibitory KIR2DL2 that strongly prevents TCR-induced activation through recognition of HLA-C molecules. Hence, a better evaluation of the role of CMV-associated HLA-E-restricted T cells in transplantation and of the impact of HLA-genotype, especially HLA-C, on their alloreactivity may determine whether they indeed represent a risk factor following organ transplantation. PMID:23226431

  8. Iris recognition in the presence of ocular disease.

    Science.gov (United States)

    Aslam, Tariq Mehmood; Tan, Shi Zhuan; Dhillon, Baljean

    2009-05-06

    Iris recognition systems are among the most accurate of all biometric technologies with immense potential for use in worldwide security applications. This study examined the effect of eye pathology on iris recognition and in particular whether eye disease could cause iris recognition systems to fail. The experiment involved a prospective cohort of 54 patients with anterior segment eye disease who were seen at the acute referral unit of the Princess Alexandra Eye Pavilion in Edinburgh. Iris camera images were obtained from patients before treatment was commenced and again at follow-up appointments after treatment had been given. The principal outcome measure was that of mathematical difference in the iris recognition templates obtained from patients' eyes before and after treatment of the eye disease. Results showed that the performance of iris recognition was remarkably resilient to most ophthalmic disease states, including corneal oedema, iridotomies (laser puncture of iris) and conjunctivitis. Problems were, however, encountered in some patients with acute inflammation of the iris (iritis/anterior uveitis). The effects of a subject developing anterior uveitis may cause current recognition systems to fail. Those developing and deploying iris recognition should be aware of the potential problems that this could cause to this key biometric technology.

  9. Recognition of oral spelling is diagnostic of the central reading processes.

    Science.gov (United States)

    Schubert, Teresa; McCloskey, Michael

    2015-01-01

    The task of recognition of oral spelling (stimulus: "C-A-T", response: "cat") is often administered to individuals with acquired written language disorders, yet there is no consensus about the underlying cognitive processes. We adjudicate between two existing hypotheses: Recognition of oral spelling uses central reading processes, or recognition of oral spelling uses central spelling processes in reverse. We tested the recognition of oral spelling and spelling to dictation abilities of a single individual with acquired dyslexia and dysgraphia. She was impaired relative to matched controls in spelling to dictation but unimpaired in recognition of oral spelling. Recognition of oral spelling for exception words (e.g., colonel) and pronounceable nonwords (e.g., larth) was intact. Our results were predicted by the hypothesis that recognition of oral spelling involves the central reading processes. We conclude that recognition of oral spelling is a useful tool for probing the integrity of the central reading processes.

  10. Epigenetic mechanisms regulate MHC and antigen processing molecules in human embryonic and induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Beatriz Suárez-Alvarez

    2010-04-01

    Full Text Available Human embryonic stem cells (hESCs are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored.We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM components and NKG2D ligands (NKG2D-L in hESCs, induced pluripotent stem cells (iPSCs and NTera2 (NT2 teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1 and tapasin (TPN components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of beta2-microglobulin (beta2m light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and beta2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs. Absence of HLA-DR and HLA-G expression was regulated by DNA methylation.Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance.

  11. Epigenetic Mechanisms Regulate MHC and Antigen Processing Molecules in Human Embryonic and Induced Pluripotent Stem Cells

    Science.gov (United States)

    Suárez-Álvarez, Beatriz; Rodriguez, Ramón M.; Calvanese, Vincenzo; Blanco-Gelaz, Miguel A.; Suhr, Steve T.; Ortega, Francisco; Otero, Jesus; Cibelli, Jose B.; Moore, Harry; Fraga, Mario F.; López-Larrea, Carlos

    2010-01-01

    Background Human embryonic stem cells (hESCs) are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC) class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored. Methodology/Principal Findings We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM) components and NKG2D ligands (NKG2D-L) in hESCs, induced pluripotent stem cells (iPSCs) and NTera2 (NT2) teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP) assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1) and tapasin (TPN) components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of β2-microglobulin (β2m) light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB) were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and β2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs). Absence of HLA-DR and HLA-G expression was regulated by DNA methylation. Conclusions/Significance Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell allograft acceptance

  12. Brain Network Involved in the Recognition of Facial Expressions of Emotion in the Early Blind

    Directory of Open Access Journals (Sweden)

    Ryo Kitada

    2011-10-01

    Full Text Available Previous studies suggest that the brain network responsible for the recognition of facial expressions of emotion (FEEs begins to emerge early in life. However, it has been unclear whether visual experience of faces is necessary for the development of this network. Here, we conducted both psychophysical and functional magnetic-resonance imaging (fMRI experiments to test the hypothesis that the brain network underlying the recognition of FEEs is not dependent on visual experience of faces. Early-blind, late-blind and sighted subjects participated in the psychophysical experiment. Regardless of group, subjects haptically identified basic FEEs at above-chance levels, without any feedback training. In the subsequent fMRI experiment, the early-blind and sighted subjects haptically identified facemasks portraying three different FEEs and casts of three different shoe types. The sighted subjects also completed a visual task that compared the same stimuli. Within the brain regions activated by the visually-identified FEEs (relative to shoes, haptic identification of FEEs (relative to shoes by the early-blind and sighted individuals activated the posterior middle temporal gyrus adjacent to the superior temporal sulcus, the inferior frontal gyrus, and the fusiform gyrus. Collectively, these results suggest that the brain network responsible for FEE recognition can develop without any visual experience of faces.

  13. The optimal viewing position in face recognition.

    Science.gov (United States)

    Hsiao, Janet H; Liu, Tina T

    2012-02-28

    In English word recognition, the best recognition performance is usually obtained when the initial fixation is directed to the left of the center (optimal viewing position, OVP). This effect has been argued to involve an interplay of left hemisphere lateralization for language processing and the perceptual experience of fixating at word beginnings most often. While both factors predict a left-biased OVP in visual word recognition, in face recognition they predict contrasting biases: People prefer to fixate the left half-face, suggesting that the OVP should be to the left of the center; nevertheless, the right hemisphere lateralization in face processing suggests that the OVP should be to the right of the center in order to project most of the face to the right hemisphere. Here, we show that the OVP in face recognition was to the left of the center, suggesting greater influence from the perceptual experience than hemispheric asymmetry in central vision. In contrast, hemispheric lateralization effects emerged when faces were presented away from the center; there was an interaction between presented visual field and location (center vs. periphery), suggesting differential influence from perceptual experience and hemispheric asymmetry in central and peripheral vision.

  14. Mapping correspondence between facial mimicry and emotion recognition in healthy subjects.

    Science.gov (United States)

    Ponari, Marta; Conson, Massimiliano; D'Amico, Nunzia Pina; Grossi, Dario; Trojano, Luigi

    2012-12-01

    We aimed at verifying the hypothesis that facial mimicry is causally and selectively involved in emotion recognition. For this purpose, in Experiment 1, we explored the effect of tonic contraction of muscles in upper or lower half of participants' face on their ability to recognize emotional facial expressions. We found that the "lower" manipulation specifically impaired recognition of happiness and disgust, the "upper" manipulation impaired recognition of anger, while both manipulations affected recognition of fear; recognition of surprise and sadness were not affected by either blocking manipulations. In Experiment 2, we verified whether emotion recognition is hampered by stimuli in which an upper or lower half-face showing an emotional expression is combined with a neutral half-face. We found that the neutral lower half-face interfered with recognition of happiness and disgust, whereas the neutral upper half impaired recognition of anger; recognition of fear and sadness was impaired by both manipulations, whereas recognition of surprise was not affected by either manipulation. Taken together, the present findings support simulation models of emotion recognition and provide insight into the role of mimicry in comprehension of others' emotional facial expressions. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  15. The mouse tumor cell lines EL4 and RMA display mosaic expression of NK-related and certain other surface molecules and appear to have a common origin.

    Science.gov (United States)

    Gays, F; Unnikrishnan, M; Shrestha, S; Fraser, K P; Brown, A R; Tristram, C M; Chrzanowska-Lightowlers, Z M; Brooks, C G

    2000-05-15

    As a potential means for facilitating studies of NK cell-related molecules, we examined the expression of these molecules on a range of mouse tumor cell lines. Of the lines we initially examined, only EL4 and RMA expressed such molecules, both lines expressing several members of the Ly49 and NKRP1 families. Unexpectedly, several of the NK-related molecules, together with certain other molecules including CD2, CD3, CD4, CD32, and CD44, were often expressed in a mosaic manner, even on freshly derived clones, indicating frequent switching in expression. In each case examined, switching was controlled at the mRNA level, with expression of CD3zeta determining expression of the entire CD3-TCR complex. Each of the variable molecules was expressed independently, with the exception that CD3 was restricted to cells that also expressed CD2. Treatment with drugs that affect DNA methylation and histone acetylation could augment the expression of at least some of the variable molecules. The striking phenotypic similarity between EL4 and RMA led us to examine the state of their TCRbeta genes. Both lines had identical rearrangements on both chromosomes, indicating that RMA is in fact a subline of EL4. Overall, these findings suggest that EL4 is an NK-T cell tumor that may have retained a genetic mechanism that permits the variable expression of a restricted group of molecules involved in recognition and signaling.

  16. The Impact of Image Quality on the Performance of Face Recognition

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    The performance of a face recognition system depends on the quality of both test and reference images participating in the face comparison process. In a forensic evaluation case involving face recognition, we do not have any control over the quality of the trace (image captured by a CCTV at a crime

  17. Neural androgen receptors modulate gene expression and social recognition but not social investigation

    Directory of Open Access Journals (Sweden)

    Sara A Karlsson

    2016-03-01

    Full Text Available The role of sex and androgen receptors (ARs for social preference and social memory is rather unknown. In this study of mice we compared males, females and males lacking ARs specifically in the nervous system, ARNesDel, with respect to social preference, assessed with the three-chambered apparatus test, and social recognition, assessed with the social discrimination procedure. In the social discrimination test we also evaluated the tentative importance of the sex of the stimulus animal. Novel object recognition and olfaction were investigated to complement the results from the social tests. Gene expression analysis was performed to reveal molecules involved in the effects of sex and androgens on social behaviors. All three test groups showed social preference in the three-chambered apparatus test. In both social tests an AR-independent sexual dimorphism was seen in the persistence of social investigation of female conspecifics, whereas the social interest towards male stimuli mice was similar in all groups. Male and female controls recognized conspecifics independent of their sex, whereas ARNesDel males recognized female but not male stimuli mice. Moreover, the non-social behaviors were not affected by AR deficiency. The gene expression analyses of hypothalamus and amygdala indicated that Oxtr, Cd38, Esr1, Cyp19a1, Ucn3, Crh and Gtf2i were differentially expressed between the three groups. In conclusion, our results suggest that ARs are required for recognition of male but not female conspecifics, while being dispensable for social investigation towards both sexes. In addition, the AR seems to regulate genes related to oxytocin, estrogen and William’s syndrome.

  18. View-Invariant Gait Recognition Through Genetic Template Segmentation

    Science.gov (United States)

    Isaac, Ebenezer R. H. P.; Elias, Susan; Rajagopalan, Srinivasan; Easwarakumar, K. S.

    2017-08-01

    Template-based model-free approach provides by far the most successful solution to the gait recognition problem in literature. Recent work discusses how isolating the head and leg portion of the template increase the performance of a gait recognition system making it robust against covariates like clothing and carrying conditions. However, most involve a manual definition of the boundaries. The method we propose, the genetic template segmentation (GTS), employs the genetic algorithm to automate the boundary selection process. This method was tested on the GEI, GEnI and AEI templates. GEI seems to exhibit the best result when segmented with our approach. Experimental results depict that our approach significantly outperforms the existing implementations of view-invariant gait recognition.

  19. Isolation and characterization of antigen-Ia complexes involved in T cell recognition

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M

    1986-01-01

    Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes, it is he......Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes...... with glutaraldehyde revealed that the ovalbumin peptide was cross-linked solely to the alpha chain of I-Ad. Planar membranes containing I-Ad-OVA complexes stimulated a T cell response with 2 X 10(4) less antigen than required when uncomplexed antigen was used, thus demonstrating the biologic importance...

  20. It takes two-skilled recognition of objects engages lateral areas in both hemispheres.

    Directory of Open Access Journals (Sweden)

    Merim Bilalić

    Full Text Available Our object recognition abilities, a direct product of our experience with objects, are fine-tuned to perfection. Left temporal and lateral areas along the dorsal, action related stream, as well as left infero-temporal areas along the ventral, object related stream are engaged in object recognition. Here we show that expertise modulates the activity of dorsal areas in the recognition of man-made objects with clearly specified functions. Expert chess players were faster than chess novices in identifying chess objects and their functional relations. Experts' advantage was domain-specific as there were no differences between groups in a control task featuring geometrical shapes. The pattern of eye movements supported the notion that experts' extensive knowledge about domain objects and their functions enabled superior recognition even when experts were not directly fixating the objects of interest. Functional magnetic resonance imaging (fMRI related exclusively the areas along the dorsal stream to chess specific object recognition. Besides the commonly involved left temporal and parietal lateral brain areas, we found that only in experts homologous areas on the right hemisphere were also engaged in chess specific object recognition. Based on these results, we discuss whether skilled object recognition does not only involve a more efficient version of the processes found in non-skilled recognition, but also qualitatively different cognitive processes which engage additional brain areas.

  1. Single-molecule force-conductance spectroscopy of hydrogen-bonded complexes

    Science.gov (United States)

    Pirrotta, Alessandro; De Vico, Luca; Solomon, Gemma C.; Franco, Ignacio

    2017-03-01

    The emerging ability to study physical properties at the single-molecule limit highlights the disparity between what is observable in an ensemble of molecules and the heterogeneous contributions of its constituent parts. A particularly convenient platform for single-molecule studies are molecular junctions where forces and voltages can be applied to individual molecules, giving access to a series of electromechanical observables that can form the basis of highly discriminating multidimensional single-molecule spectroscopies. Here, we computationally examine the ability of force and conductance to inform about molecular recognition events at the single-molecule limit. For this, we consider the force-conductance characteristics of a prototypical class of hydrogen bonded bimolecular complexes sandwiched between gold electrodes. The complexes consist of derivatives of a barbituric acid and a Hamilton receptor that can form up to six simultaneous hydrogen bonds. The simulations combine classical molecular dynamics of the mechanical deformation of the junction with non-equilibrium Green's function computations of the electronic transport. As shown, in these complexes hydrogen bonds mediate transport either by directly participating as a possible transport pathway or by stabilizing molecular conformations with enhanced conductance properties. Further, we observe that force-conductance correlations can be very sensitive to small changes in the chemical structure of the complexes and provide detailed information about the behavior of single molecules that cannot be gleaned from either measurement alone. In fact, there are regions during the elongation that are only mechanically active, others that are only conductance active, and regions where both force and conductance changes as the complex is mechanically manipulated. The implication is that force and conductance provide complementary information about the evolution of molecules in junctions that can be used to

  2. Pattern recognition

    CERN Document Server

    Theodoridis, Sergios

    2003-01-01

    Pattern recognition is a scientific discipline that is becoming increasingly important in the age of automation and information handling and retrieval. Patter Recognition, 2e covers the entire spectrum of pattern recognition applications, from image analysis to speech recognition and communications. This book presents cutting-edge material on neural networks, - a set of linked microprocessors that can form associations and uses pattern recognition to ""learn"" -and enhances student motivation by approaching pattern recognition from the designer's point of view. A direct result of more than 10

  3. Electrochemical sensor for dopamine based on a novel graphene-molecular imprinted polymers composite recognition element

    DEFF Research Database (Denmark)

    Mao, Yan; Bao, Yu; Gan, Shiyu

    2011-01-01

    A novel composite of graphene sheets/Congo red-molecular imprinted polymers (GSCR-MIPs) was synthesized through free radical polymerization (FRP) and applied as a molecular recognition element to construct dopamine (DA) electrochemical sensor. The template molecules (DA) were firstly absorbed...... at the GSCR surface due to their excellent affinity, and subsequently, selective copolymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA) was further achieved at the GSCR surface. Potential scanning was presented to extract DA molecules from the imprinted polymers film...

  4. Structural requirements for the interaction between class II MHC molecules and peptide antigens

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Appella, E

    1990-01-01

    of binding, it is possible to define certain structural features of peptides that are associated with the capacity to bind to a particular MHC specificity (IA(d) or IE(d)); 3) IA(d) and IE(d) molecules recognize different and independent structures on the antigen molecule; 4) only about 10% of the single...... IA(d) and IE(d) molecules and their peptide ligands, we found that some structural characteristics apply to both antigen-MHC interactions. In particular, we found: 1) each MHC molecule is capable of binding many unrelated peptides through the same peptide-binding site; 2) despite this permissiveness...... amino acid substitutions tested on two IA(d)- and IE(d)-binding peptides had significant effect on their MHC-binding capacities, while over 80% of these substitutions significantly impaired T cell recognition of the Ia-peptide complex; 5) based on the segregation between residues that are crucial for T...

  5. Problems of Face Recognition in Patients with Behavioral Variant Frontotemporal Dementia.

    Science.gov (United States)

    Chandra, Sadanandavalli Retnaswami; Patwardhan, Ketaki; Pai, Anupama Ramakanth

    2017-01-01

    Faces are very special as they are most essential for social cognition in humans. It is partly understood that face processing in its abstractness involves several extra striate areas. One of the most important causes for caregiver suffering in patients with anterior dementia is lack of empathy. This apart from being a behavioral disorder could be also due to failure to categorize the emotions of the people around them. Inlusion criteria: DSM IV for Bv FTD Tested for prosopagnosia - familiar faces, famous face, smiling face, crying face and reflected face using a simple picture card (figure 1). Advanced illness and mixed causes. 46 patients (15 females, 31 males) 24 had defective face recognition. (mean age 51.5),10/15 females (70%) and 14/31males(47. Familiar face recognition defect was found in 6/10 females and 6/14 males. Total- 40%(6/15) females and 19.35%(6/31)males with FTD had familiar face recognition. Famous Face: 9/10 females and 7/14 males. Total- 60% (9/15) females with FTD had famous face recognition defect as against 22.6%(7/31) males with FTD Smiling face defects in 8/10 female and no males. Total- 53.33% (8/15) females. Crying face recognition defect in 3/10 female and 2 /14 males. Total- 20%(3/15) females and 6.5%(2/31) males. Reflected face recognition defect in 4 females. Famous face recognition and positive emotion recognition defect in 80%, only 20% comprehend positive emotions, Face recognition defects are found in only 45% of males and more common in females. Face recognition is more affected in females with FTD There is differential involvement of different aspects of the face recognition could be one of the important factor underlying decline in the emotional and social behavior of these patients. Understanding these pathological processes will give more insight regarding patient behavior.

  6. Effect of dopamine therapy on nonverbal affect burst recognition in Parkinson's disease.

    Directory of Open Access Journals (Sweden)

    Julie Péron

    Full Text Available BACKGROUND: Parkinson's disease (PD provides a model for investigating the involvement of the basal ganglia and mesolimbic dopaminergic system in the recognition of emotions from voices (i.e., emotional prosody. Although previous studies of emotional prosody recognition in PD have reported evidence of impairment, none of them compared PD patients at different stages of the disease, or ON and OFF dopamine replacement therapy, making it difficult to determine whether their impairment was due to general cognitive deterioration or to a more specific dopaminergic deficit. METHODS: We explored the involvement of the dopaminergic pathways in the recognition of nonverbal affect bursts (onomatopoeias in 15 newly diagnosed PD patients in the early stages of the disease, 15 PD patients in the advanced stages of the disease and 15 healthy controls. The early PD group was studied in two conditions: ON and OFF dopaminergic therapy. RESULTS: Results showed that the early PD patients performed more poorly in the ON condition than in the OFF one, for overall emotion recognition, as well as for the recognition of anger, disgust and fear. Additionally, for anger, the early PD ON patients performed more poorly than controls. For overall emotion recognition, both advanced PD patients and early PD ON patients performed more poorly than controls. Analysis of continuous ratings on target and nontarget visual analog scales confirmed these patterns of results, showing a systematic emotional bias in both the advanced PD and early PD ON (but not OFF patients compared with controls. CONCLUSIONS: These results i confirm the involvement of the dopaminergic pathways and basal ganglia in emotional prosody recognition, and ii suggest a possibly deleterious effect of dopatherapy on affective abilities in the early stages of PD.

  7. An intermolecular binding mechanism involving multiple LysM domains mediates carbohydrate recognition by an endopeptidase

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Jaslyn E. M. M. [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark); Midtgaard, Søren Roi [University of Copenhagen, Universitetsparken 5, 2100 Copenhagen (Denmark); Gysel, Kira [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark); Thygesen, Mikkel B.; Sørensen, Kasper K.; Jensen, Knud J. [University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C (Denmark); Stougaard, Jens; Thirup, Søren; Blaise, Mickaël, E-mail: mickael.blaise@cpbs.cnrs.fr [Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus (Denmark)

    2015-03-01

    The crystal and solution structures of the T. thermophilus NlpC/P60 d, l-endopeptidase as well as the co-crystal structure of its N-terminal LysM domains bound to chitohexaose allow a proposal to be made regarding how the enzyme recognizes peptidoglycan. LysM domains, which are frequently present as repetitive entities in both bacterial and plant proteins, are known to interact with carbohydrates containing N-acetylglucosamine (GlcNAc) moieties, such as chitin and peptidoglycan. In bacteria, the functional significance of the involvement of multiple LysM domains in substrate binding has so far lacked support from high-resolution structures of ligand-bound complexes. Here, a structural study of the Thermus thermophilus NlpC/P60 endopeptidase containing two LysM domains is presented. The crystal structure and small-angle X-ray scattering solution studies of this endopeptidase revealed the presence of a homodimer. The structure of the two LysM domains co-crystallized with N-acetyl-chitohexaose revealed a new intermolecular binding mode that may explain the differential interaction between LysM domains and short or long chitin oligomers. By combining the structural information with the three-dimensional model of peptidoglycan, a model suggesting how protein dimerization enhances the recognition of peptidoglycan is proposed.

  8. Forensic Speaker Recognition Law Enforcement and Counter-Terrorism

    CERN Document Server

    Patil, Hemant

    2012-01-01

    Forensic Speaker Recognition: Law Enforcement and Counter-Terrorism is an anthology of the research findings of 35 speaker recognition experts from around the world. The volume provides a multidimensional view of the complex science involved in determining whether a suspect’s voice truly matches forensic speech samples, collected by law enforcement and counter-terrorism agencies, that are associated with the commission of a terrorist act or other crimes. While addressing such topics as the challenges of forensic case work, handling speech signal degradation, analyzing features of speaker recognition to optimize voice verification system performance, and designing voice applications that meet the practical needs of law enforcement and counter-terrorism agencies, this material all sounds a common theme: how the rigors of forensic utility are demanding new levels of excellence in all aspects of speaker recognition. The contributors are among the most eminent scientists in speech engineering and signal process...

  9. The role of nitric oxide in the object recognition memory.

    Science.gov (United States)

    Pitsikas, Nikolaos

    2015-05-15

    The novel object recognition task (NORT) assesses recognition memory in animals. It is a non-rewarded paradigm that it is based on spontaneous exploratory behavior in rodents. This procedure is widely used for testing the effects of compounds on recognition memory. Recognition memory is a type of memory severely compromised in schizophrenic and Alzheimer's disease patients. Nitric oxide (NO) is sought to be an intra- and inter-cellular messenger in the central nervous system and its implication in learning and memory is well documented. Here I intended to critically review the role of NO-related compounds on different aspects of recognition memory. Current analysis shows that both NO donors and NO synthase (NOS) inhibitors are involved in object recognition memory and suggests that NO might be a promising target for cognition impairments. However, the potential neurotoxicity of NO would add a note of caution in this context. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. The hierarchical brain network for face recognition.

    Science.gov (United States)

    Zhen, Zonglei; Fang, Huizhen; Liu, Jia

    2013-01-01

    Numerous functional magnetic resonance imaging (fMRI) studies have identified multiple cortical regions that are involved in face processing in the human brain. However, few studies have characterized the face-processing network as a functioning whole. In this study, we used fMRI to identify face-selective regions in the entire brain and then explore the hierarchical structure of the face-processing network by analyzing functional connectivity among these regions. We identified twenty-five regions mainly in the occipital, temporal and frontal cortex that showed a reliable response selective to faces (versus objects) across participants and across scan sessions. Furthermore, these regions were clustered into three relatively independent sub-networks in a face-recognition task on the basis of the strength of functional connectivity among them. The functionality of the sub-networks likely corresponds to the recognition of individual identity, retrieval of semantic knowledge and representation of emotional information. Interestingly, when the task was switched to object recognition from face recognition, the functional connectivity between the inferior occipital gyrus and the rest of the face-selective regions were significantly reduced, suggesting that this region may serve as an entry node in the face-processing network. In sum, our study provides empirical evidence for cognitive and neural models of face recognition and helps elucidate the neural mechanisms underlying face recognition at the network level.

  11. Activity Recognition Using Inertial Sensing for Healthcare, Wellbeing and Sports Applications: A Survey

    NARCIS (Netherlands)

    Avci, A.; Bosch, S.; Marin Perianu, Mihai; Marin Perianu, Raluca; Havinga, Paul J.M.

    This paper surveys the current research directions of activity recognition using inertial sensors, with potential application in healthcare, wellbeing and sports. The analysis of related work is organized according to the five main steps involved in the activity recognition process: preprocessing,

  12. Recognition of lysophosphatidylcholine by type II NKT cells and protection from an inflammatory liver disease.

    Science.gov (United States)

    Maricic, Igor; Girardi, Enrico; Zajonc, Dirk M; Kumar, Vipin

    2014-11-01

    Lipids presented by the MHC class I-like molecule, CD1d, are recognized by NK T (NKT) cells, which can be broadly categorized into two subsets. The well-characterized type I NKT cells express a semi-invariant TCR and can recognize both α- and β-linked glycolipids, whereas type II NKT cells are less well studied, express a relatively diverse TCR repertoire, and recognize β-linked lipids. Recent structural studies have shown a distinct mode of recognition of a self-glycolipid sulfatide bound to CD1d by a type II NKT TCR. To further characterize Ag recognition by these cells, we have used the structural data and screened other small molecules able to bind to CD1d and activate type II NKT cells. Using plate-bound CD1d and APC-based Ag presentation assay, we found that phospholipids such as lysophosphatidylcholine (LPC) can stimulate the sulfatide-reactive type II NKT hybridoma Hy19.3 in a CD1d-dependent manner. Using plasmon resonance studies, we found that this type II NKT TCR binds with CD1d-bound LPC with micromolar affinities similar to that for sulfatide. Furthermore, LPC-mediated activation of type II NKT cells leads to anergy induction in type I NKT cells and affords protection from Con A-induced hepatitis. These data indicate that, in addition to self-glycolipids, self-lysophospholipids are also recognized by type II NKT cells. Because lysophospholipids are involved during inflammation, our findings have implications for not only understanding activation of type II NKT cells in physiological settings, but also for the development of immune intervention in inflammatory diseases. Copyright © 2014 by The American Association of Immunologists, Inc.

  13. 8 CFR 292.2 - Organizations qualified for recognition; requests for recognition; withdrawal of recognition...

    Science.gov (United States)

    2010-01-01

    ...; requests for recognition; withdrawal of recognition; accreditation of representatives; roster. 292.2...; withdrawal of recognition; accreditation of representatives; roster. (a) Qualifications of organizations. A non-profit religious, charitable, social service, or similar organization established in the United...

  14. Partially Supervised Approach in Signal Recognition

    Directory of Open Access Journals (Sweden)

    Catalina COCIANU

    2009-01-01

    Full Text Available The paper focuses on the potential of principal directions based approaches in signal classification and recognition. In probabilistic models, the classes are represented in terms of multivariate density functions, and an object coming from a certain class is modeled as a random vector whose repartition has the density function corresponding to this class. In cases when there is no statistical information concerning the set of density functions corresponding to the classes involved in the recognition process, usually estimates based on the information extracted from available data are used instead. In the proposed methodology, the characteristics of a class are given by a set of eigen vectors of the sample covariance matrix. The overall dissimilarity of an object X with a given class C is computed as the disturbance of the structure of C, when X is allotted to C. A series of tests concerning the behavior of the proposed recognition algorithm are reported in the final section of the paper.

  15. Multicharged Ion-induced simple molecule fragmentation dynamics

    International Nuclear Information System (INIS)

    Tarisien, M.

    2003-10-01

    The aim of this work is to study the dynamics of swift multicharged ion-induced fragmentation of diatomic (CO) and triatomic (CO 2 ) molecules. Performed at the GANIL facility, this study used the Recoil Ion Momentum Spectroscopy technique (RIMS), which consists of a time-of-flight mass spectrometer, coupled with a multi-hit capability position sensitive detector (delay line anode). The high-resolution measurement of the kinetic energy distribution released (KER) during the CO fragmentation points out the limitation of the Coulomb Explosion Model, revealing, for example, the di-cation CO 2 + electronic state contribution in the case of C + /O + fragmentation pathway. Furthermore, the multi-ionization cross section dependence with the orientation of the internuclear axis of CO is compared with a geometrical model calculation. Finally, different behaviours are observed for the dissociation dynamics of a triatomic molecule (CO 2 ). While triple ionization leads mainly to a synchronous concerted fragmentation dynamics, a weak fraction of dissociating molecule follows a sequential dynamics involving CO 2 + metastable states. In the case of double ionization, (CO 2 ) 2+ di-cation dissociation dynamics is asynchronously concerted and has been interpreted using a simple model involving an asymmetrical vibration of the molecule. (author)

  16. On the relation between face and object recognition in developmental prosopagnosia

    DEFF Research Database (Denmark)

    Gerlach, Christian; Klargaard, Solja K.; Starrfelt, Randi

    2016-01-01

    There is an ongoing debate about whether face recognition and object recognition constitute separate domains. Clarification of this issue can have important theoretical implications as face recognition is often used as a prime example of domain-specificity in mind and brain. An important source...... of input to this debate comes from studies of individuals with developmental prosopagnosia, suggesting that face recognition can be selectively impaired. We put the selectivity hypothesis to test by assessing the performance of 10 individuals with developmental prosopagnosia on demanding tests of visual...... object processing involving both regular and degraded drawings. None of the individuals exhibited a clear dissociation between face and object recognition, and as a group they were significantly more affected by degradation of objects than control participants. Importantly, we also find positive...

  17. Object Recognition and Localization: The Role of Tactile Sensors

    Directory of Open Access Journals (Sweden)

    Achint Aggarwal

    2014-02-01

    Full Text Available Tactile sensors, because of their intrinsic insensitivity to lighting conditions and water turbidity, provide promising opportunities for augmenting the capabilities of vision sensors in applications involving object recognition and localization. This paper presents two approaches for haptic object recognition and localization for ground and underwater environments. The first approach called Batch Ransac and Iterative Closest Point augmented Particle Filter (BRICPPF is based on an innovative combination of particle filters, Iterative-Closest-Point algorithm, and a feature-based Random Sampling and Consensus (RANSAC algorithm for database matching. It can handle a large database of 3D-objects of complex shapes and performs a complete six-degree-of-freedom localization of static objects. The algorithms are validated by experimentation in ground and underwater environments using real hardware. To our knowledge this is the first instance of haptic object recognition and localization in underwater environments. The second approach is biologically inspired, and provides a close integration between exploration and recognition. An edge following exploration strategy is developed that receives feedback from the current state of recognition. A recognition by parts approach is developed which uses the BRICPPF for object sub-part recognition. Object exploration is either directed to explore a part until it is successfully recognized, or is directed towards new parts to endorse the current recognition belief. This approach is validated by simulation experiments.

  18. Electromyographic Grasp Recognition for a Five Fingered Robotic Hand

    Directory of Open Access Journals (Sweden)

    Nayan M. Kakoty

    2012-09-01

    Full Text Available This paper presents classification of grasp types based on surface electromyographic signals. Classification is through radial basis function kernel support vector machine using sum of wavelet decomposition coefficients of the EMG signals. In a study involving six subjects, we achieved an average recognition rate of 86%. The electromyographic grasp recognition together with a 8-bit microcontroller has been employed to control a fivefingered robotic hand to emulate six grasp types used during 70% daily living activities.

  19. Recent Advances in Multinuclear NMR Spectroscopy for Chiral Recognition of Organic Compounds

    Directory of Open Access Journals (Sweden)

    Márcio S. Silva

    2017-02-01

    Full Text Available Nuclear magnetic resonance (NMR is a powerful tool for the elucidation of chemical structure and chiral recognition. In the last decade, the number of probes, media, and experiments to analyze chiral environments has rapidly increased. The evaluation of chiral molecules and systems has become a routine task in almost all NMR laboratories, allowing for the determination of molecular connectivities and the construction of spatial relationships. Among the features that improve the chiral recognition abilities by NMR is the application of different nuclei. The simplicity of the multinuclear NMR spectra relative to 1H, the minimal influence of the experimental conditions, and the larger shift dispersion make these nuclei especially suitable for NMR analysis. Herein, the recent advances in multinuclear (19F, 31P, 13C, and 77Se NMR spectroscopy for chiral recognition of organic compounds are presented. The review describes new chiral derivatizing agents and chiral solvating agents used for stereodiscrimination and the assignment of the absolute configuration of small organic compounds.

  20. Water-assisted dehalogenation of thionyl chloride in the presence of water molecules.

    Science.gov (United States)

    Yeung, Chi Shun; Ng, Ping Leung; Guan, Xiangguo; Phillips, David Lee

    2010-04-01

    A second-order Møller-Plesset perturbation theory (MP2) and density functional theory (DFT) investigation of the dehalogenation reactions of thionyl chloride is reported, in which water molecules (up to seven) were explicitly involved in the reaction complex. The dehalogenation processes of thionyl chloride were found to be dramatically catalyzed by water molecules. The reaction rate became significantly faster as more water molecules became involved in the reaction complex. The dehalogenation processes can be reasonably simulated by the gas-phase water cluster models, which reveals that water molecules can help to solvate the thionyl chloride molecules and activate the release of the Cl(-) leaving group. The computed activation energies were used to compare the calculations to available experimental data.

  1. Probing binding hot spots at protein-RNA recognition sites.

    Science.gov (United States)

    Barik, Amita; Nithin, Chandran; Karampudi, Naga Bhushana Rao; Mukherjee, Sunandan; Bahadur, Ranjit Prasad

    2016-01-29

    We use evolutionary conservation derived from structure alignment of polypeptide sequences along with structural and physicochemical attributes of protein-RNA interfaces to probe the binding hot spots at protein-RNA recognition sites. We find that the degree of conservation varies across the RNA binding proteins; some evolve rapidly compared to others. Additionally, irrespective of the structural class of the complexes, residues at the RNA binding sites are evolutionary better conserved than those at the solvent exposed surfaces. For recognitions involving duplex RNA, residues interacting with the major groove are better conserved than those interacting with the minor groove. We identify multi-interface residues participating simultaneously in protein-protein and protein-RNA interfaces in complexes where more than one polypeptide is involved in RNA recognition, and show that they are better conserved compared to any other RNA binding residues. We find that the residues at water preservation site are better conserved than those at hydrated or at dehydrated sites. Finally, we develop a Random Forests model using structural and physicochemical attributes for predicting binding hot spots. The model accurately predicts 80% of the instances of experimental ΔΔG values in a particular class, and provides a stepping-stone towards the engineering of protein-RNA recognition sites with desired affinity. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. DMBT1 functions as pattern-recognition molecule for poly-sulfated and poly-phosphorylated ligands

    DEFF Research Database (Denmark)

    End, Caroline; Bikker, Floris; Renner, Marcus

    2009-01-01

    at unraveling the molecular basis of its function in mucosal protection and of its broad pathogen-binding specificity. We report that DMBT1 directly interacts with dextran sulfate sodium (DSS) and carrageenan, a structurally similar sulfated polysaccharide, which is used as a texturizer and thickener in human...... dietary products. However, binding of DMBT1 does not reduce the cytotoxic effects of these agents to intestinal epithelial cells in vitro. DSS and carrageenan compete for DMBT1-mediated bacterial aggregation via interaction with its bacterial-recognition motif. Competition and ELISA studies identify poly...

  3. Roles of dental pulp fibroblasts in the recognition of bacterium-related factors and subsequent development of pulpitis

    Directory of Open Access Journals (Sweden)

    Tadashi Nakanishi

    2011-08-01

    Full Text Available As caries-related bacteria invade deeply into dentin and come into close proximity to the pulp, inflammatory cells (such as lymphocytes, macrophages and neutrophils infiltrate into the bacterium-invaded area and consequently pulpitis develops. Many types of cytokines and adhesion molecules are responsible for the initiation and progression of pulpitis. Dental pulp fibroblasts, a major cell type in the dental pulp, also have capacity to produce pro-inflammatory cytokines and express adhesion molecules in response to pathogen-associated molecular patterns (PAMPs, including lipopolysaccharide. The innate immune system senses microbial infection using pattern recognition receptors, such as Toll-like receptors (TLRs and nucleotide-binding oligomerization domain (NOD, for PAMPs. In this review, we summarize the roles of dental pulp fibroblasts in the recognition of invaded bacterium-related factors via TLR and NOD pathways, and the subsequent pulpal immune responses, leading to progressive pulpitis.

  4. Reactive oxygen species, essential molecules, during plant-pathogen interactions.

    Science.gov (United States)

    Camejo, Daymi; Guzmán-Cedeño, Ángel; Moreno, Alexander

    2016-06-01

    Reactive oxygen species (ROS) are continually generated as a consequence of the normal metabolism in aerobic organisms. Accumulation and release of ROS into cell take place in response to a wide variety of adverse environmental conditions including salt, temperature, cold stresses and pathogen attack, among others. In plants, peroxidases class III, NADPH oxidase (NOX) locates in cell wall and plasma membrane, respectively, may be mainly enzymatic systems involving ROS generation. It is well documented that ROS play a dual role into cells, acting as important signal transduction molecules and as toxic molecules with strong oxidant power, however some aspects related to its function during plant-pathogen interactions remain unclear. This review focuses on the principal enzymatic systems involving ROS generation addressing the role of ROS as signal molecules during plant-pathogen interactions. We described how the chloroplasts, mitochondria and peroxisomes perceive the external stimuli as pathogen invasion, and trigger resistance response using ROS as signal molecule. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  5. The recognition of facial emotion expressions in Parkinson's disease.

    Science.gov (United States)

    Assogna, Francesca; Pontieri, Francesco E; Caltagirone, Carlo; Spalletta, Gianfranco

    2008-11-01

    A limited number of studies in Parkinson's Disease (PD) suggest a disturbance of recognition of facial emotion expressions. In particular, disgust recognition impairment has been reported in unmedicated and medicated PD patients. However, the results are rather inconclusive in the definition of the degree and the selectivity of emotion recognition impairment, and an associated impairment of almost all basic facial emotions in PD is also described. Few studies have investigated the relationship with neuropsychiatric and neuropsychological symptoms with mainly negative results. This inconsistency may be due to many different problems, such as emotion assessment, perception deficit, cognitive impairment, behavioral symptoms, illness severity and antiparkinsonian therapy. Here we review the clinical characteristics and neural structures involved in the recognition of specific facial emotion expressions, and the plausible role of dopamine transmission and dopamine replacement therapy in these processes. It is clear that future studies should be directed to clarify all these issues.

  6. Real-Time Multiview Recognition of Human Gestures by Distributed Image Processing

    Directory of Open Access Journals (Sweden)

    Sato Kosuke

    2010-01-01

    Full Text Available Since a gesture involves a dynamic and complex motion, multiview observation and recognition are desirable. For the better representation of gestures, one needs to know, in the first place, from which views a gesture should be observed. Furthermore, it becomes increasingly important how the recognition results are integrated when larger numbers of camera views are considered. To investigate these problems, we propose a framework under which multiview recognition is carried out, and an integration scheme by which the recognition results are integrated online and in realtime. For performance evaluation, we use the ViHASi (Virtual Human Action Silhouette public image database as a benchmark and our Japanese sign language (JSL image database that contains 18 kinds of hand signs. By examining the recognition rates of each gesture for each view, we found gestures that exhibit view dependency and the gestures that do not. Also, we found that the view dependency itself could vary depending on the target gesture sets. By integrating the recognition results of different views, our swarm-based integration provides more robust and better recognition performance than individual fixed-view recognition agents.

  7. A review of the immune molecules in the sea cucumber.

    Science.gov (United States)

    Xue, Zhuang; Li, Hui; Wang, Xiuli; Li, Xia; Liu, Yang; Sun, Jing; Liu, Cenjie

    2015-05-01

    It is very important to identify and characterize the immune-related genes that respond to pathogens. Until recently, only some of the immune-related genes in sea cucumbers had been characterized. Their expression patterns after pathogen challenges have been analyzed via expressed sequence tag libraries, microarray studies and proteomic approaches. These genes include lectins, antimicrobial peptides, lysozyme, enzymes, clotting protein, pattern recognition proteins, Toll receptors, complement C3 and other humoral factors that might participate in the innate immune system of sea cucumbers. Although the participation of some of these immune molecules in the sea cucumber's innate immune defense against invading pathogens has been demonstrated, the functions of many of the molecules remain unclear. This review focuses on the discovery and functional characterization of the immune-related molecules from the sea cucumber for the first time and provides new insights into the immune mechanisms of the sea cucumber, which opens new possibilities for developing drugs for novel anti-bacterial and antiviral applications in fisheries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Cytotoxic T cell recognition of an endogenous class I HLA peptide presented by a class II HLA molecule.

    Science.gov (United States)

    Chen, B P; Madrigal, A; Parham, P

    1990-09-01

    Human leukocytes were stimulated in vitro with peptides corresponding in sequence to the highly variable helix of the alpha 1 domain of various HLA-B and -C molecules. A CD4+ CD8- cytotoxic T cell line, CTL-AV, that is specific for the HLA-B7 peptide presented by HLA-DR11.1 was obtained. The HLA-DR11.2 molecule, which only differs at three residues from HLA-DR11.1, did not present the HLA-B7 peptide to CTL-AV. Peptides from the alpha 1 domain helix of other HLA-A and HLA-B molecules, but not HLA-C molecules, competed with the HLA-B7 peptide for binding to HLA-DR11.1. A cell line (WT50) that coexpresses HLA-B7 and HLA-DR11.1 was killed by CTL-AV in the absence of any added HLA-B7 peptide. The processing and presentation of HLA-B7 in these cells appears to be through the endogenous, and not the exogenous, pathway of antigen presentation. Thus, Brefeldin A inhibits presentation and chloroquine does not. Furthermore, introduction of purified HLA-B7 molecules into HLA-DR11.1+, HLA-B7- cells by cytoplasmic loading via osmotic lysis of pinosomes, but not by simple incubation, rendered them susceptible to CTL-AV killing. These results provide an example of class II major histocompatibility complex (MHC) presentation of a constitutively synthesized self protein that uses the endogenous pathway of antigen presentation. They also emphasize the capacity for presentation of MHC peptides by MHC molecules.

  9. Human hippocampal and parahippocampal activity during visual associative recognition memory for spatial and nonspatial stimulus configurations.

    Science.gov (United States)

    Düzel, Emrah; Habib, Reza; Rotte, Michael; Guderian, Sebastian; Tulving, Endel; Heinze, Hans-Jochen

    2003-10-15

    Evidence from animal studies points to the importance of the parahippocampal region (PHR) [including entorhinal, perirhinal, and parahippocampal (PHC) cortices] for recognition of visual stimuli. Recent findings in animals suggest that PHR may also be involved in visual associative recognition memory for configurations of stimuli. Thus far, however, such involvement has not been demonstrated in humans. In fact, it has been argued that associative recognition in humans is critically dependent on the hippocampal formation (HF). To better understand the division of function between HF and PHR during recognition memory in humans, we measured the activity of both areas in healthy young adults during an associative recognition memory task using functional magnetic resonance imaging. To more precisely characterize the nature of the associations that might be coded by the HF and PHR during recognition, subjects were required to learn and were later tested for associations based on either the spatial arrangements of two stimuli or the identity of two stimuli (a face and a tool). An area in the PHC was found to be more active for recognized old configurations than new configurations in both the spatial and identity conditions. The HF, on the other hand, was more active for recognition of new configurations than old configurations and also more active in the spatial than the identity condition. These data highlight the involvement of PHR in the long-term coding of associative relationships between stimuli and help to clarify the nature of its functional distinction from the HF.

  10. Early visual experience and the recognition of basic facial expressions: involvement of the middle temporal and inferior frontal gyri during haptic identification by the early blind.

    Science.gov (United States)

    Kitada, Ryo; Okamoto, Yuko; Sasaki, Akihiro T; Kochiyama, Takanori; Miyahara, Motohide; Lederman, Susan J; Sadato, Norihiro

    2013-01-01

    Face perception is critical for social communication. Given its fundamental importance in the course of evolution, the innate neural mechanisms can anticipate the computations necessary for representing faces. However, the effect of visual deprivation on the formation of neural mechanisms that underlie face perception is largely unknown. We previously showed that sighted individuals can recognize basic facial expressions by haptics surprisingly well. Moreover, the inferior frontal gyrus (IFG) and posterior superior temporal sulcus (pSTS) in the sighted subjects are involved in haptic and visual recognition of facial expressions. Here, we conducted both psychophysical and functional magnetic-resonance imaging (fMRI) experiments to determine the nature of the neural representation that subserves the recognition of basic facial expressions in early blind individuals. In a psychophysical experiment, both early blind and sighted subjects haptically identified basic facial expressions at levels well above chance. In the subsequent fMRI experiment, both groups haptically identified facial expressions and shoe types (control). The sighted subjects then completed the same task visually. Within brain regions activated by the visual and haptic identification of facial expressions (relative to that of shoes) in the sighted group, corresponding haptic identification in the early blind activated regions in the inferior frontal and middle temporal gyri. These results suggest that the neural system that underlies the recognition of basic facial expressions develops supramodally even in the absence of early visual experience.

  11. Threats of Password Pattern Leakage Using Smartwatch Motion Recognition Sensors

    Directory of Open Access Journals (Sweden)

    Jihun Kim

    2017-06-01

    Full Text Available Thanks to the development of Internet of Things (IoT technologies, wearable markets have been growing rapidly. Smartwatches can be said to be the most representative product in wearable markets, and involve various hardware technologies in order to overcome the limitations of small hardware. Motion recognition sensors are a representative example of those hardware technologies. However, smartwatches and motion recognition sensors that can be worn by users may pose security threats of password pattern leakage. In the present paper, passwords are inferred through experiments to obtain password patterns inputted by users using motion recognition sensors, and verification of the results and the accuracy of the results is shown.

  12. Probing the role of interfacial waters in protein-DNA recognition using a hybrid implicit/explicit solvation model

    Science.gov (United States)

    Li, Shen; Bradley, Philip

    2013-01-01

    When proteins bind to their DNA target sites, ordered water molecules are often present at the protein-DNA interface bridging protein and DNA through hydrogen bonds. What is the role of these ordered interfacial waters? Are they important determinants of the specificity of DNA sequence recognition, or do they act in binding in a primarily non-specific manner, by improving packing of the interface, shielding unfavorable electrostatic interactions, and solvating unsatisfied polar groups that are inaccessible to bulk solvent? When modeling details of structure and binding preferences, can fully implicit solvent models be fruitfully applied to protein-DNA interfaces, or must the individualistic properties of these interfacial waters be accounted for? To address these questions, we have developed a hybrid implicit/explicit solvation model that specifically accounts for the locations and orientations of small numbers of DNA-bound water molecules while treating the majority of the solvent implicitly. Comparing the performance of this model to its fully implicit counterpart, we find that explicit treatment of interfacial waters results in a modest but significant improvement in protein sidechain placement and DNA sequence recovery. Base-by-base comparison of the performance of the two models highlights DNA sequence positions whose recognition may be dependent on interfacial water. Our study offers large-scale statistical evidence for the role of ordered water for protein DNA recognition, together with detailed examination of several well-characterized systems. In addition, our approach provides a template for modeling explicit water molecules at interfaces that should be extensible to other systems. PMID:23444044

  13. Unraveling a Hotspot for TCR Recognition on HLA-A2: Evidence Against the Existence of Peptide-independent TCR Binding Determinants

    International Nuclear Information System (INIS)

    Gagnon, Susan J.; Borbulevych, Oleg Y.; Davis-Harrison, Rebecca L.; Baxter, Tiffany K.; Clemens, John R.; Armstrong, Kathryn M.; Turner, Richard V.; Damirjian, Marale; Biddison, William E.; Baker, Brian M.

    2005-01-01

    T cell receptor (TCR) recognition of peptide takes place in the context of the major histocompatibility complex (MHC) molecule, which accounts for approximately two-thirds of the peptide/MHC buried surface. Using the class I MHC HLA-A2 and a large panel of mutants, we have previously shown that surface mutations that disrupt TCR recognition vary with the identity of the peptide. The single exception is Lys66 on the HLA-A2 α1 helix, which when mutated to alanine disrupts recognition for 93% of over 250 different T cell clones or lines, independent of which peptide is bound. Thus, Lys66 could serve as a peptide-independent TCR binding determinant. Here, we have examined the role of Lys66 in TCR recognition of HLA-A2 in detail. The structure of a peptide/HLA-A2 molecule with the K66A mutation indicates that although the mutation induces no major structural changes, it results in the exposure of a negatively charged glutamate (Glu63) underneath Lys66. Concurrent replacement of Glu63 with glutamine restores TCR binding and function for T cells specific for five different peptides presented by HLA-A2. Thus, the positive charge on Lys66 does not serve to guide all TCRs onto the HLA-A2 molecule in a manner required for productive signaling. Furthermore, electrostatic calculations indicate that Lys66 does not contribute to the stability of two TCR-peptide/HLA-A2 complexes. Our findings are consistent with the notion that each TCR arrives at a unique solution of how to bind a peptide/MHC, most strongly influenced by the chemical and structural features of the bound peptide. This would not rule out an intrinsic affinity of TCRs for MHC molecules achieved through multiple weak interactions, but for HLA-A2 the collective mutational data place limits on the role of any single MHC amino acid side-chain in driving TCR binding in a peptide-independent fashion.

  14. Unpacking Recognition and Esteem in School Pedagogies

    Science.gov (United States)

    Wulf, Christoph; Bittner, Martin; Clemens, Iris; Kellermann, Ingrid

    2012-01-01

    The article focuses on pedagogical practices of recognition and esteem (Wertschatzung) and on the question of how those practices can be appropriately studied and epistemologically grasped. The investigation involves an inner-city elementary school in a socio-economically problematic district. With regard to the communication forms in this…

  15. How a hobby can shape cognition: visual word recognition in competitive Scrabble players.

    Science.gov (United States)

    Hargreaves, Ian S; Pexman, Penny M; Zdrazilova, Lenka; Sargious, Peter

    2012-01-01

    Competitive Scrabble is an activity that involves extraordinary word recognition experience. We investigated whether that experience is associated with exceptional behavior in the laboratory in a classic visual word recognition paradigm: the lexical decision task (LDT). We used a version of the LDT that involved horizontal and vertical presentation and a concreteness manipulation. In Experiment 1, we presented this task to a group of undergraduates, as these participants are the typical sample in word recognition studies. In Experiment 2, we compared the performance of a group of competitive Scrabble players with a group of age-matched nonexpert control participants. The results of a series of cognitive assessments showed that the Scrabble players and control participants differed only in Scrabble-specific skills (e.g., anagramming). Scrabble expertise was associated with two specific effects (as compared to controls): vertical fluency (relatively less difficulty judging lexicality for words presented in the vertical orientation) and semantic deemphasis (smaller concreteness effects for word responses). These results suggest that visual word recognition is shaped by experience, and that with experience there are efficiencies to be had even in the adult word recognition system.

  16. Crystal structure of Vδ1 T cell receptor in complex with CD1d-sulfatide shows MHC-like recognition of a self-lipid by human γδ T cells.

    Science.gov (United States)

    Luoma, Adrienne M; Castro, Caitlin D; Mayassi, Toufic; Bembinster, Leslie A; Bai, Li; Picard, Damien; Anderson, Brian; Scharf, Louise; Kung, Jennifer E; Sibener, Leah V; Savage, Paul B; Jabri, Bana; Bendelac, Albert; Adams, Erin J

    2013-12-12

    The nature of the antigens recognized by γδ T cells and their potential recognition of major histocompatibility complex (MHC)-like molecules has remained unclear. Members of the CD1 family of lipid-presenting molecules are suggested ligands for Vδ1 TCR-expressing γδ T cells, the major γδ lymphocyte population in epithelial tissues. We crystallized a Vδ1 TCR in complex with CD1d and the self-lipid sulfatide, revealing the unusual recognition of CD1d by germline Vδ1 residues spanning all complementarity-determining region (CDR) loops, as well as sulfatide recognition separately encoded by nongermline CDR3δ residues. Binding and functional analysis showed that CD1d presenting self-lipids, including sulfatide, was widely recognized by gut Vδ1+ γδ T cells. These findings provide structural demonstration of MHC-like recognition of a self-lipid by γδ T cells and reveal the prevalence of lipid recognition by innate-like T cell populations. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Syllabic Length Effect in Visual Word Recognition

    Directory of Open Access Journals (Sweden)

    Roya Ranjbar Mohammadi

    2014-07-01

    Full Text Available Studies on visual word recognition have resulted in different and sometimes contradictory proposals as Multi-Trace Memory Model (MTM, Dual-Route Cascaded Model (DRC, and Parallel Distribution Processing Model (PDP. The role of the number of syllables in word recognition was examined by the use of five groups of English words and non-words. The reaction time of the participants to these words was measured using reaction time measuring software. The results indicated that there was syllabic effect on recognition of both high and low frequency words. The pattern was incremental in terms of syllable number. This pattern prevailed in high and low frequency words and non-words except in one syllable words. In general, the results are in line with the PDP model which claims that a single processing mechanism is used in both words and non-words recognition. In other words, the findings suggest that lexical items are mainly processed via a lexical route.  A pedagogical implication of the findings would be that reading in English as a foreign language involves analytical processing of the syllable of the words.

  18. Mice lacking the synaptic adhesion molecule Neph2/Kirrel3 display moderate hyperactivity and defective novel object preference

    Directory of Open Access Journals (Sweden)

    Su Yeon eChoi

    2015-07-01

    Full Text Available Synaptic adhesion molecules regulate diverse aspects of neuronal synapse development, including synapse specificity, formation, and maturation. Neph2, also known as Kirrel3, is an immunoglobulin superfamily adhesion molecule implicated in intellectual disability, neurocognitive delay associated with Jacobsen syndrome, and autism spectrum disorders. We here report mice lacking Neph2 (Neph2–/– mice display moderate hyperactivity in a familiar but not novel environment and novel object recognition deficit with normal performances in Morris water maze spatial learning and memory, contextual fear conditioning and extinction, and pattern separation tests. These mice show normal levels of anxiety-like behaviors, social interaction, and repetitive behaviors. At the synapse level, Neph2–/– dentate gyrus granule cells exhibit unaltered dendritic spine density and spontaneous excitatory synaptic transmission. These results suggest that Neph2 is important for normal locomotor activity and object recognition memory.

  19. Molecular Recognition in the Colloidal World.

    Science.gov (United States)

    Elacqua, Elizabeth; Zheng, Xiaolong; Shillingford, Cicely; Liu, Mingzhu; Weck, Marcus

    2017-11-21

    Colloidal self-assembly is a bottom-up technique to fabricate functional nanomaterials, with paramount interest stemming from programmable assembly of smaller building blocks into dynamic crystalline domains and photonic materials. Multiple established colloidal platforms feature diverse shapes and bonding interactions, while achieving specific orientations along with short- and long-range order. A major impediment to their universal use as building blocks for predesigned architectures is the inability to precisely dictate and control particle functionalization and concomitant reversible self-assembly. Progress in colloidal self-assembly necessitates the development of strategies that endow bonding specificity and directionality within assemblies. Methodologies that emulate molecular and polymeric three-dimensional (3D) architectures feature elements of covalent bonding, while high-fidelity molecular recognition events have been installed to realize responsive reconfigurable assemblies. The emergence of anisotropic 'colloidal molecules', coupled with the ability to site-specifically decorate particle surfaces with supramolecular recognition motifs, has facilitated the formation of superstructures via directional interactions and shape recognition. In this Account, we describe supramolecular assembly routes to drive colloidal particles into precisely assembled architectures or crystalline lattices via directional noncovalent molecular interactions. The design principles are based upon the fabrication of colloidal particles bearing surface-exposed functional groups that can undergo programmable conjugation to install recognition motifs with high fidelity. Modular and versatile by design, our strategy allows for the introduction and integration of molecular recognition principles into the colloidal world. We define noncovalent molecular interactions as site-specific forces that are predictable (i.e., feature selective and controllable complementary bonding partners

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

    Science.gov (United States)

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

    2014-01-01

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

  1. Goal-seeking neural net for recall and recognition

    Science.gov (United States)

    Omidvar, Omid M.

    1990-07-01

    Neural networks have been used to mimic cognitive processes which take place in animal brains. The learning capability inherent in neural networks makes them suitable candidates for adaptive tasks such as recall and recognition. The synaptic reinforcements create a proper condition for adaptation, which results in memorization, formation of perception, and higher order information processing activities. In this research a model of a goal seeking neural network is studied and the operation of the network with regard to recall and recognition is analyzed. In these analyses recall is defined as retrieval of stored information where little or no matching is involved. On the other hand recognition is recall with matching; therefore it involves memorizing a piece of information with complete presentation. This research takes the generalized view of reinforcement in which all the signals are potential reinforcers. The neuronal response is considered to be the source of the reinforcement. This local approach to adaptation leads to the goal seeking nature of the neurons as network components. In the proposed model all the synaptic strengths are reinforced in parallel while the reinforcement among the layers is done in a distributed fashion and pipeline mode from the last layer inward. A model of complex neuron with varying threshold is developed to account for inhibitory and excitatory behavior of real neuron. A goal seeking model of a neural network is presented. This network is utilized to perform recall and recognition tasks. The performance of the model with regard to the assigned tasks is presented.

  2. Early recognition of technological opportunities. Realization and perspectives

    International Nuclear Information System (INIS)

    Stegelmann, H.U.; Peters, H.P.; Stein, G.; Muench, E.

    1988-03-01

    In cooperation with the American consulting company Arthur D. Little, a number of procedures, including evaluation of literature data banks, expert interviews and expert workshops, were tried. A three-step concept was finally developed involving identification of candidate technologies (identification), collection of information on these candidates (exploration), ultimately leading to an assessment of the candidate technologies (evaluation). Such a procedure basically enables long-term observation of the scientific policy decisions. This information may serve to identify the deficits and strength of the German scientific system in comparison to that of other countries. Such a system permits the survey and documentation of scientists' subjective expectations on the trends of technology developments and the associated economic and other social consequences. It became apparent that this concept should not raise expectations too high and that it is not essentially different from the advisory instruments already employed today (advisory councils, expert consultants), but rather that these established procedures are merely systematized and supplemented by further information sources (e.g. data banks). In implementing this study two central sets of problems were identified which must be overcome: The early recognition of opportunities is in the long run based on analysts infiltrating the existing network of specialist scientists and examining the information in circulation there with respect to the aims of early recognition so that access to this network is a decisive requirement for an institutionalization of early recognition; incentive systems must be created motivating scientists to become actively involved in the early recognition of technological opportunities. (orig./HP) [de

  3. Under-resourced speech recognition based on the speech manifold

    CSIR Research Space (South Africa)

    Sahraeian, R

    2015-09-01

    Full Text Available Conventional acoustic modeling involves estimating many parameters to effectively model feature distributions. The sparseness of speech and text data, however, degrades the reliability of the estimation process and makes speech recognition a...

  4. The relationship between protein synthesis and protein degradation in object recognition memory.

    Science.gov (United States)

    Furini, Cristiane R G; Myskiw, Jociane de C; Schmidt, Bianca E; Zinn, Carolina G; Peixoto, Patricia B; Pereira, Luiza D; Izquierdo, Ivan

    2015-11-01

    For decades there has been a consensus that de novo protein synthesis is necessary for long-term memory. A second round of protein synthesis has been described for both extinction and reconsolidation following an unreinforced test session. Recently, it was shown that consolidation and reconsolidation depend not only on protein synthesis but also on protein degradation by the ubiquitin-proteasome system (UPS), a major mechanism responsible for protein turnover. However, the involvement of UPS on consolidation and reconsolidation of object recognition memory remains unknown. Here we investigate in the CA1 region of the dorsal hippocampus the involvement of UPS-mediated protein degradation in consolidation and reconsolidation of object recognition memory. Animals with infusion cannulae stereotaxically implanted in the CA1 region of the dorsal hippocampus, were exposed to an object recognition task. The UPS inhibitor β-Lactacystin did not affect the consolidation and the reconsolidation of object recognition memory at doses known to affect other forms of memory (inhibitory avoidance, spatial learning in a water maze) while the protein synthesis inhibitor anisomycin impaired the consolidation and the reconsolidation of the object recognition memory. However, β-Lactacystin was able to reverse the impairment caused by anisomycin on the reconsolidation process in the CA1 region of the hippocampus. Therefore, it is possible to postulate a direct link between protein degradation and protein synthesis during the reconsolidation of the object recognition memory. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Preliminary Analysis of Automatic Speech Recognition and Synthesis Technology.

    Science.gov (United States)

    1983-05-01

    ANDELES CA 0 SHDAP ET AL MAY 93 UNCISSIFED UCG -020-8 MDA04-8’-C-415F/ 17/2 N mE = h IEEE 11111 10’ ~ 2.0 11-41 & 11111I25IID MICROCOPY RESOLUTION TEST...speech. Private industry, which sees a major market for improved speech recognition systems, is attempting to solve the problems involved in...manufacturer is able to market such a recognition system. A second requirement for the spotting of keywords in distress signals concerns the need for a

  6. Interaction Between Hydrogen Molecules and a Closed Nanotube

    Directory of Open Access Journals (Sweden)

    Tarasov Egor

    2016-01-01

    Full Text Available The present paper assesses the state of low-energy molecules in the vicinity of the crystal structure of a closed nanotube. It is proposed to use the continuum description of the impact energy from carbon graphene structures. In this approach, a closed tube consists of an open part and two fullerene hemispheres. Calculations revealed that adsorption of gas molecules by surface crystals is not the case of capturing by a part of the nano-object surface, but that of involvement of molecules in a complex orbital motion around the particle.

  7. New method for recognition of sterol signalling molecules: Methinium salts as receptors for sulphated steroids

    Czech Academy of Sciences Publication Activity Database

    Kejík, Z.; Bříza, T.; Králová, Jarmila; Mikula, I.; Poučková, P.; Martásek, P.; Král, V.

    2015-01-01

    Roč. 94, February 2015 (2015), s. 15-20 ISSN 1878-5867 R&D Projects: GA TA ČR(CZ) TE01020028; GA ČR(CZ) GAP303/11/1291; GA MŠk(CZ) LH14008; GA MŠk(CZ) CZ.1.07/2.300/30.0060; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:68378050 Keywords : Polymethinium salts * Sulphated sterols * Molecular recognition * Synthetic receptors Subject RIV: EB - Genetics ; Molecular Biology

  8. Recognition and cinema: new ways of approaching

    Directory of Open Access Journals (Sweden)

    José Luis GARCÍA MARTÍNEZ

    2016-09-01

    Full Text Available Along the following lines we propose the use of films for educational purposes. Our main argument, based on philosophical grounds, shows the use of film format to emphasize and understand people’s motivations and actions. The reflections brought about by empathy with the characters are the first step in the approach of the topic of recognition, a term that in the medical framework involves taking into account the various aspects of inter-human relationships. Recognition of “the other” as he/she stands, implies addressing differences and providing a better doctor-patient relationship. The analysis of several films might encourage the acknowledgement of recognition as one of the key concepts to understand our ways of relating within plural societies with different lifestyles and different outlooks on the world. We believe that the effort made in dealing with such topics results in greater closeness to the patient and, therefore, better care.

  9. Speech and audio processing for coding, enhancement and recognition

    CERN Document Server

    Togneri, Roberto; Narasimha, Madihally

    2015-01-01

    This book describes the basic principles underlying the generation, coding, transmission and enhancement of speech and audio signals, including advanced statistical and machine learning techniques for speech and speaker recognition with an overview of the key innovations in these areas. Key research undertaken in speech coding, speech enhancement, speech recognition, emotion recognition and speaker diarization are also presented, along with recent advances and new paradigms in these areas. ·         Offers readers a single-source reference on the significant applications of speech and audio processing to speech coding, speech enhancement and speech/speaker recognition. Enables readers involved in algorithm development and implementation issues for speech coding to understand the historical development and future challenges in speech coding research; ·         Discusses speech coding methods yielding bit-streams that are multi-rate and scalable for Voice-over-IP (VoIP) Networks; ·     �...

  10. Application of pattern recognition techniques to crime analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bender, C.F.; Cox, L.A. Jr.; Chappell, G.A.

    1976-08-15

    The initial goal was to evaluate the capabilities of current pattern recognition techniques when applied to existing computerized crime data. Performance was to be evaluated both in terms of the system's capability to predict crimes and to optimize police manpower allocation. A relation was sought to predict the crime's susceptibility to solution, based on knowledge of the crime type, location, time, etc. The preliminary results of this work are discussed. They indicate that automatic crime analysis involving pattern recognition techniques is feasible, and that efforts to determine optimum variables and techniques are warranted. 47 figures (RWR)

  11. Optical Pattern Recognition

    Science.gov (United States)

    Yu, Francis T. S.; Jutamulia, Suganda

    2008-10-01

    Contributors; Preface; 1. Pattern recognition with optics Francis T. S. Yu and Don A. Gregory; 2. Hybrid neural networks for nonlinear pattern recognition Taiwei Lu; 3. Wavelets, optics, and pattern recognition Yao Li and Yunglong Sheng; 4. Applications of the fractional Fourier transform to optical pattern recognition David Mendlovic, Zeev Zalesky and Haldum M. Oxaktas; 5. Optical implementation of mathematical morphology Tien-Hsin Chao; 6. Nonlinear optical correlators with improved discrimination capability for object location and recognition Leonid P. Yaroslavsky; 7. Distortion-invariant quadratic filters Gregory Gheen; 8. Composite filter synthesis as applied to pattern recognition Shizhou Yin and Guowen Lu; 9. Iterative procedures in electro-optical pattern recognition Joseph Shamir; 10. Optoelectronic hybrid system for three-dimensional object pattern recognition Guoguang Mu, Mingzhe Lu and Ying Sun; 11. Applications of photrefractive devices in optical pattern recognition Ziangyang Yang; 12. Optical pattern recognition with microlasers Eung-Gi Paek; 13. Optical properties and applications of bacteriorhodopsin Q. Wang Song and Yu-He Zhang; 14. Liquid-crystal spatial light modulators Aris Tanone and Suganda Jutamulia; 15. Representations of fully complex functions on real-time spatial light modulators Robert W. Cohn and Laurence G. Hassbrook; Index.

  12. Tensor Rank Preserving Discriminant Analysis for Facial Recognition.

    Science.gov (United States)

    Tao, Dapeng; Guo, Yanan; Li, Yaotang; Gao, Xinbo

    2017-10-12

    Facial recognition, one of the basic topics in computer vision and pattern recognition, has received substantial attention in recent years. However, for those traditional facial recognition algorithms, the facial images are reshaped to a long vector, thereby losing part of the original spatial constraints of each pixel. In this paper, a new tensor-based feature extraction algorithm termed tensor rank preserving discriminant analysis (TRPDA) for facial image recognition is proposed; the proposed method involves two stages: in the first stage, the low-dimensional tensor subspace of the original input tensor samples was obtained; in the second stage, discriminative locality alignment was utilized to obtain the ultimate vector feature representation for subsequent facial recognition. On the one hand, the proposed TRPDA algorithm fully utilizes the natural structure of the input samples, and it applies an optimization criterion that can directly handle the tensor spectral analysis problem, thereby decreasing the computation cost compared those traditional tensor-based feature selection algorithms. On the other hand, the proposed TRPDA algorithm extracts feature by finding a tensor subspace that preserves most of the rank order information of the intra-class input samples. Experiments on the three facial databases are performed here to determine the effectiveness of the proposed TRPDA algorithm.

  13. A new selective developmental deficit: Impaired object recognition with normal face recognition.

    Science.gov (United States)

    Germine, Laura; Cashdollar, Nathan; Düzel, Emrah; Duchaine, Bradley

    2011-05-01

    Studies of developmental deficits in face recognition, or developmental prosopagnosia, have shown that individuals who have not suffered brain damage can show face recognition impairments coupled with normal object recognition (Duchaine and Nakayama, 2005; Duchaine et al., 2006; Nunn et al., 2001). However, no developmental cases with the opposite dissociation - normal face recognition with impaired object recognition - have been reported. The existence of a case of non-face developmental visual agnosia would indicate that the development of normal face recognition mechanisms does not rely on the development of normal object recognition mechanisms. To see whether a developmental variant of non-face visual object agnosia exists, we conducted a series of web-based object and face recognition tests to screen for individuals showing object recognition memory impairments but not face recognition impairments. Through this screening process, we identified AW, an otherwise normal 19-year-old female, who was then tested in the lab on face and object recognition tests. AW's performance was impaired in within-class visual recognition memory across six different visual categories (guns, horses, scenes, tools, doors, and cars). In contrast, she scored normally on seven tests of face recognition, tests of memory for two other object categories (houses and glasses), and tests of recall memory for visual shapes. Testing confirmed that her impairment was not related to a general deficit in lower-level perception, object perception, basic-level recognition, or memory. AW's results provide the first neuropsychological evidence that recognition memory for non-face visual object categories can be selectively impaired in individuals without brain damage or other memory impairment. These results indicate that the development of recognition memory for faces does not depend on intact object recognition memory and provide further evidence for category-specific dissociations in visual

  14. Recognition of TLR2 N-Glycans: Critical Role in ArtinM Immunomodulatory Activity

    Science.gov (United States)

    da Silva, Thiago Aparecido; Ruas, Luciana Pereira; Nohara, Lilian L.; de Almeida, Igor Correia; Roque-Barreira, Maria Cristina

    2014-01-01

    TLR2 plays a critical role in the protection against Paracoccidioides brasiliensis conferred by ArtinM administration. ArtinM, a D-mannose-binding lectin from Artocarpus heterophyllus, induces IL-12 production in macrophages and dendritic cells, which accounts for the T helper1 immunity that results from ArtinM administration. We examined the direct interaction of ArtinM with TLR2using HEK293A cells transfected with TLR2, alone or in combination with TLR1 or TLR6, together with accessory proteins. Stimulation with ArtinM induced NF-κB activation and interleukin (IL)-8 production in cells transfected with TLR2, TLR2/1, or TLR2/6. Murine macrophages that were stimulated with ArtinM had augmented TLR2 mRNA expression. Furthermore, pre-incubation of unstimulated macrophages with an anti-TLR2 antibody reduced the cell labeling with ArtinM. In addition, a microplate assay revealed that ArtinM bound to TLR2 molecules that had been captured by specific antibodies from a macrophages lysate. Notably,ArtinM binding to TLR2 was selectively inhibited when the lectin was pre-incubated with mannotriose. The biological relevance of the direct interaction of ArtinM with TLR2 glycans was assessed using macrophages from TLR2-KOmice, which produced significantly lower levels of IL-12 and IL-10 in response to ArtinM than macrophages from wild-type mice. Pre-treatment of murine macrophages with pharmacological inhibitors of signaling molecules demonstrated the involvement of p38 MAPK and JNK in the IL-12 production induced by ArtinM and the involvement ofPI3K in IL-10 production. Thus, ArtinM interacts directly with TLR2 or TLR2 heterodimers in a carbohydrate recognition-dependent manner and functions as a TLR2 agonist with immunomodulatory properties. PMID:24892697

  15. Recognition of TLR2 N-glycans: critical role in ArtinM immunomodulatory activity.

    Directory of Open Access Journals (Sweden)

    Vania Sammartino Mariano

    Full Text Available TLR2 plays a critical role in the protection against Paracoccidioides brasiliensis conferred by ArtinM administration. ArtinM, a D-mannose-binding lectin from Artocarpus heterophyllus, induces IL-12 production in macrophages and dendritic cells, which accounts for the T helper1 immunity that results from ArtinM administration. We examined the direct interaction of ArtinM with TLR2using HEK293A cells transfected with TLR2, alone or in combination with TLR1 or TLR6, together with accessory proteins. Stimulation with ArtinM induced NF-κB activation and interleukin (IL-8 production in cells transfected with TLR2, TLR2/1, or TLR2/6. Murine macrophages that were stimulated with ArtinM had augmented TLR2 mRNA expression. Furthermore, pre-incubation of unstimulated macrophages with an anti-TLR2 antibody reduced the cell labeling with ArtinM. In addition, a microplate assay revealed that ArtinM bound to TLR2 molecules that had been captured by specific antibodies from a macrophages lysate. Notably,ArtinM binding to TLR2 was selectively inhibited when the lectin was pre-incubated with mannotriose. The biological relevance of the direct interaction of ArtinM with TLR2 glycans was assessed using macrophages from TLR2-KOmice, which produced significantly lower levels of IL-12 and IL-10 in response to ArtinM than macrophages from wild-type mice. Pre-treatment of murine macrophages with pharmacological inhibitors of signaling molecules demonstrated the involvement of p38 MAPK and JNK in the IL-12 production induced by ArtinM and the involvement ofPI3K in IL-10 production. Thus, ArtinM interacts directly with TLR2 or TLR2 heterodimers in a carbohydrate recognition-dependent manner and functions as a TLR2 agonist with immunomodulatory properties.

  16. User involvement in mental health rehabilitation

    DEFF Research Database (Denmark)

    Petersen, Kirsten; Hounsgaard, Lise; Borg, Tove

    2012-01-01

    reading, structural analysis, and critical interpretation. Findings: The study showed that user involvement in rehabilitation was experienced by the users as a struggle for self-determination and recognition. Being able to decide and to have influence on daily activities and everyday life, together...... with having goals to reach during rehabilitation, were viewed as valuable. Situations without influence or involving coercion were reported especially during periods of illness or hospitalization. Conclusions: The results of this study contribute to knowledge about user involvement from service users...

  17. Measurement of the ground-state distributions in bistable mechanically interlocked molecules using slow scan rate cyclic voltammetry.

    Science.gov (United States)

    Fahrenbach, Albert C; Barnes, Jonathan C; Li, Hao; Benítez, Diego; Basuray, Ashish N; Fang, Lei; Sue, Chi-Hau; Barin, Gokhan; Dey, Sanjeev K; Goddard, William A; Stoddart, J Fraser

    2011-12-20

    In donor-acceptor mechanically interlocked molecules that exhibit bistability, the relative populations of the translational isomers--present, for example, in a bistable [2]rotaxane, as well as in a couple of bistable [2]catenanes of the donor-acceptor vintage--can be elucidated by slow scan rate cyclic voltammetry. The practice of transitioning from a fast scan rate regime to a slow one permits the measurement of an intermediate redox couple that is a function of the equilibrium that exists between the two translational isomers in the case of all three mechanically interlocked molecules investigated. These intermediate redox potentials can be used to calculate the ground-state distribution constants, K. Whereas, (i) in the case of the bistable [2]rotaxane, composed of a dumbbell component containing π-electron-rich tetrathiafulvalene and dioxynaphthalene recognition sites for the ring component (namely, a tetracationic cyclophane, containing two π-electron-deficient bipyridinium units), a value for K of 10 ± 2 is calculated, (ii) in the case of the two bistable [2]catenanes--one containing a crown ether with tetrathiafulvalene and dioxynaphthalene recognition sites for the tetracationic cyclophane, and the other, tetrathiafulvalene and butadiyne recognition sites--the values for K are orders (one and three, respectively) of magnitude greater. This observation, which has also been probed by theoretical calculations, supports the hypothesis that the extra stability of one translational isomer over the other is because of the influence of the enforced side-on donor-acceptor interactions brought about by both π-electron-rich recognition sites being part of a macrocyclic polyether.

  18. Study of the electronic properties of organic molecules within a metal-molecule-metal junction

    International Nuclear Information System (INIS)

    Lambert, Mathieu

    2003-01-01

    This ph-D thesis is about electronic transport through organic molecules inserted in a metal molecule-metal junction. We describe first a simple process to prepare sub-3 nm gaps by controllable breakage (under an electrical stress) of gold wires lithographed on a SiO 2 Si substrate at low temperature (4.2 K). We show that the involved mechanism is thermally assisted electromigration. We observe that current-voltage (I-V) characteristics of resulting electrodes are stable up to ∼5 V. which gives access to the well-known Fowler-Nordheim regime in the I-V, allowing an accurate characterisation of the gap size. The average gap is found lo be between 1.5 nm in width and 2.5 eV in height. Molecules and nanoparticles have then been inserted in the junction in the case of nanoparticles for example. The resulting IV clearly shows the suppression of electrical current at low bias known as Coulomb blockade. Characteristic of single-electron tunnelling through nanometer-sized structures, finally we fabricated a single-electron tunneling device based on Au nanoparticles connected to the electrodes via terthiophene (T3) molecule. We use the silicon substrate, separated from the planar structure by a silicon oxide of 200 nm, as an electrostatic gate and observed clear current modulation with possible signature of the transport properties of the terthiophene molecules. (author) [fr

  19. Leveraging Automatic Speech Recognition Errors to Detect Challenging Speech Segments in TED Talks

    Science.gov (United States)

    Mirzaei, Maryam Sadat; Meshgi, Kourosh; Kawahara, Tatsuya

    2016-01-01

    This study investigates the use of Automatic Speech Recognition (ASR) systems to epitomize second language (L2) listeners' problems in perception of TED talks. ASR-generated transcripts of videos often involve recognition errors, which may indicate difficult segments for L2 listeners. This paper aims to discover the root-causes of the ASR errors…

  20. Oxytocin is not involved in luteolysis and early maternal recognition of pregnancy (MRP) in alpacas.

    Science.gov (United States)

    Ciccarelli, Michela; Waqas, Muhammad Salman; Pru, James K; Tibary, Ahmed

    2017-12-01

    Pregnancy maintenance depends on the maternal recognition of pregnancy (MRP), a physiological process by which the lifespan of the corpus luteum is prolonged. This mechanism is not well characterized in camelids. The objectives of the present research were to determine if exogenous oxytocin prolongs the corpus luteum activity in alpacas and to evaluate expression and localization of oxytocin receptors within the endometrium at 9 and 14days post-mating. In the oxytocin studies, plasma progesterone profiles were determined after ovulation in the same alpacas on 2 cycles: one cycle without oxytocin treatment and one cycle with oxytocin treatment. Oxytocin was administered daily by intramuscular injections (IM) at a dose of 20IU (experiment 1, n=6) or 60IU (experiment 2, n=7 from day 3 through day 10 after induction of ovulation with GnRH IM. There was no significant difference in the length of the luteal phase (i.e. corpus luteum lifespan) between the treated and control cycles using either 20 or 60IU of oxytocin. In the final experiment, uteri from open and pregnant alpacas (n=4 per group) at 9 and 14days post-mating were evaluated for expressions of oxytocin receptors by immunohistochemistry. No significant difference (P≤0.05) in the expression of oxytocin receptors was observed between open and pregnant animals in either staining intensity or tissue localization. We conclude that oxytocin is not involved in luteolysis and early MRP in alpacas. Published by Elsevier B.V.

  1. Cuticular hydrocarbons as potential kin recognition cues in a subsocial spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine; D'Ettorre, Patrizia

    2011-01-01

    of recognition cues in subsocial species can provide insights into evolutionary pathways leading to permanent sociality and kin-selected benefits of cooperation. In subsocial spiders, empirical evidence suggests the existence of both kin recognition and benefits of cooperating with kin, whereas the cues for kin...... recognition have yet to be identified. However, cuticular hydrocarbons have been proposed to be involved in regulation of tolerance and interattraction in spider sociality. Here, we show that subsocial Stegodyphus lineatus spiderlings have cuticular hydrocarbon profiles that are sibling-group specific, making...... be branched alkanes that are influenced very little by rearing conditions and may be genetically determined. This indicates that a specific group of cuticular chemicals, namely branched alkanes, could have evolved to act as social recognition cues in both insects and spiders....

  2. Bayesian Action–Perception Computational Model: Interaction of Production and Recognition of Cursive Letters

    Science.gov (United States)

    Gilet, Estelle; Diard, Julien; Bessière, Pierre

    2011-01-01

    In this paper, we study the collaboration of perception and action representations involved in cursive letter recognition and production. We propose a mathematical formulation for the whole perception–action loop, based on probabilistic modeling and Bayesian inference, which we call the Bayesian Action–Perception (BAP) model. Being a model of both perception and action processes, the purpose of this model is to study the interaction of these processes. More precisely, the model includes a feedback loop from motor production, which implements an internal simulation of movement. Motor knowledge can therefore be involved during perception tasks. In this paper, we formally define the BAP model and show how it solves the following six varied cognitive tasks using Bayesian inference: i) letter recognition (purely sensory), ii) writer recognition, iii) letter production (with different effectors), iv) copying of trajectories, v) copying of letters, and vi) letter recognition (with internal simulation of movements). We present computer simulations of each of these cognitive tasks, and discuss experimental predictions and theoretical developments. PMID:21674043

  3. The effects of acute social isolation on long-term social recognition memory.

    Science.gov (United States)

    Leser, Noam; Wagner, Shlomo

    2015-10-01

    The abilities to recognize individual animals of the same species and to distinguish them from other individuals are the basis for all mammalian social organizations and relationships. These abilities, termed social recognition memory, can be explored in mice and rats using their innate tendency to investigate novel social stimuli more persistently than familiar ones. Using this methodology it was found that social recognition memory is mediated by a specific neural network in the brain, the activity of which is modulated by several molecules, such the neuropeptides oxytocin and vasopressin. During the last 15 years several independent studies have revealed that social recognition memory of mice and rats depends upon their housing conditions. Specifically, long-term social recognition memory cannot be formed as shortly as few days following social isolation of the animal. This rapid and reversible impairment caused by acute social isolation seems to be specific to social memory and has not been observed in other types of memory. Here we review these studies and suggest that this unique system may serve for exploring of the mechanisms underlying the well-known negative effects of partial or perceived social isolation on human mental health. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. The different faces of one's self: an fMRI study into the recognition of current and past self-facial appearances.

    Science.gov (United States)

    Apps, Matthew A J; Tajadura-Jiménez, Ana; Turley, Grainne; Tsakiris, Manos

    2012-11-15

    Mirror self-recognition is often considered as an index of self-awareness. Neuroimaging studies have identified a neural circuit specialised for the recognition of one's own current facial appearance. However, faces change considerably over a lifespan, highlighting the necessity for representations of one's face to continually be updated. We used fMRI to investigate the different neural circuits involved in the recognition of the childhood and current, adult, faces of one's self. Participants viewed images of either their own face as it currently looks morphed with the face of a familiar other or their childhood face morphed with the childhood face of the familiar other. Activity in areas which have a generalised selectivity for faces, including the inferior occipital gyrus, the superior parietal lobule and the inferior temporal gyrus, varied with the amount of current self in an image. Activity in areas involved in memory encoding and retrieval, including the hippocampus and the posterior cingulate gyrus, and areas involved in creating a sense of body ownership, including the temporo-parietal junction and the inferior parietal lobule, varied with the amount of childhood self in an image. We suggest that the recognition of one's own past or present face is underpinned by different cognitive processes in distinct neural circuits. Current self-recognition engages areas involved in perceptual face processing, whereas childhood self-recognition recruits networks involved in body ownership and memory processing. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Neuropeptide S interacts with the basolateral amygdala noradrenergic system in facilitating object recognition memory consolidation.

    Science.gov (United States)

    Han, Ren-Wen; Xu, Hong-Jiao; Zhang, Rui-San; Wang, Pei; Chang, Min; Peng, Ya-Li; Deng, Ke-Yu; Wang, Rui

    2014-01-01

    The noradrenergic activity in the basolateral amygdala (BLA) was reported to be involved in the regulation of object recognition memory. As the BLA expresses high density of receptors for Neuropeptide S (NPS), we investigated whether the BLA is involved in mediating NPS's effects on object recognition memory consolidation and whether such effects require noradrenergic activity. Intracerebroventricular infusion of NPS (1nmol) post training facilitated 24-h memory in a mouse novel object recognition task. The memory-enhancing effect of NPS could be blocked by the β-adrenoceptor antagonist propranolol. Furthermore, post-training intra-BLA infusions of NPS (0.5nmol/side) improved 24-h memory for objects, which was impaired by co-administration of propranolol (0.5μg/side). Taken together, these results indicate that NPS interacts with the BLA noradrenergic system in improving object recognition memory during consolidation. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Current trends in small vocabulary speech recognition for equipment control

    Science.gov (United States)

    Doukas, Nikolaos; Bardis, Nikolaos G.

    2017-09-01

    Speech recognition systems allow human - machine communication to acquire an intuitive nature that approaches the simplicity of inter - human communication. Small vocabulary speech recognition is a subset of the overall speech recognition problem, where only a small number of words need to be recognized. Speaker independent small vocabulary recognition can find significant applications in field equipment used by military personnel. Such equipment may typically be controlled by a small number of commands that need to be given quickly and accurately, under conditions where delicate manual operations are difficult to achieve. This type of application could hence significantly benefit by the use of robust voice operated control components, as they would facilitate the interaction with their users and render it much more reliable in times of crisis. This paper presents current challenges involved in attaining efficient and robust small vocabulary speech recognition. These challenges concern feature selection, classification techniques, speaker diversity and noise effects. A state machine approach is presented that facilitates the voice guidance of different equipment in a variety of situations.

  7. Early visual experience and the recognition of basic facial expressions: involvement of the middle temporal and inferior frontal gyri during haptic identification by the early blind

    Science.gov (United States)

    Kitada, Ryo; Okamoto, Yuko; Sasaki, Akihiro T.; Kochiyama, Takanori; Miyahara, Motohide; Lederman, Susan J.; Sadato, Norihiro

    2012-01-01

    Face perception is critical for social communication. Given its fundamental importance in the course of evolution, the innate neural mechanisms can anticipate the computations necessary for representing faces. However, the effect of visual deprivation on the formation of neural mechanisms that underlie face perception is largely unknown. We previously showed that sighted individuals can recognize basic facial expressions by haptics surprisingly well. Moreover, the inferior frontal gyrus (IFG) and posterior superior temporal sulcus (pSTS) in the sighted subjects are involved in haptic and visual recognition of facial expressions. Here, we conducted both psychophysical and functional magnetic-resonance imaging (fMRI) experiments to determine the nature of the neural representation that subserves the recognition of basic facial expressions in early blind individuals. In a psychophysical experiment, both early blind and sighted subjects haptically identified basic facial expressions at levels well above chance. In the subsequent fMRI experiment, both groups haptically identified facial expressions and shoe types (control). The sighted subjects then completed the same task visually. Within brain regions activated by the visual and haptic identification of facial expressions (relative to that of shoes) in the sighted group, corresponding haptic identification in the early blind activated regions in the inferior frontal and middle temporal gyri. These results suggest that the neural system that underlies the recognition of basic facial expressions develops supramodally even in the absence of early visual experience. PMID:23372547

  8. Localization and Recognition of Dynamic Hand Gestures Based on Hierarchy of Manifold Classifiers

    Science.gov (United States)

    Favorskaya, M.; Nosov, A.; Popov, A.

    2015-05-01

    Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin detector, normalized skeleton representation of one or two hands, and motion history representing by motion vectors normalized through predetermined directions (8 and 16 in our case). Each dynamic gesture is separated into a set of sub-gestures in order to predict a trajectory and remove those samples of gestures, which do not satisfy to current trajectory. The posture classifiers involve the normalized skeleton representation of palm and fingers and relative finger positions using fingertips. The min-max criterion is used for trajectory recognition, and the decision tree technique was applied for posture recognition of sub-gestures. For experiments, a dataset "Multi-modal Gesture Recognition Challenge 2013: Dataset and Results" including 393 dynamic hand-gestures was chosen. The proposed method yielded 84-91% recognition accuracy, in average, for restricted set of dynamic gestures.

  9. LOCALIZATION AND RECOGNITION OF DYNAMIC HAND GESTURES BASED ON HIERARCHY OF MANIFOLD CLASSIFIERS

    Directory of Open Access Journals (Sweden)

    M. Favorskaya

    2015-05-01

    Full Text Available Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin detector, normalized skeleton representation of one or two hands, and motion history representing by motion vectors normalized through predetermined directions (8 and 16 in our case. Each dynamic gesture is separated into a set of sub-gestures in order to predict a trajectory and remove those samples of gestures, which do not satisfy to current trajectory. The posture classifiers involve the normalized skeleton representation of palm and fingers and relative finger positions using fingertips. The min-max criterion is used for trajectory recognition, and the decision tree technique was applied for posture recognition of sub-gestures. For experiments, a dataset “Multi-modal Gesture Recognition Challenge 2013: Dataset and Results” including 393 dynamic hand-gestures was chosen. The proposed method yielded 84–91% recognition accuracy, in average, for restricted set of dynamic gestures.

  10. Involvement of the oxytocin system in the bed nucleus of the stria terminalis in the sex-specific regulation of social recognition

    Science.gov (United States)

    Dumais, Kelly M.; Alonso, Andrea G.; Immormino, Marisa A.; Bredewold, Remco; Veenema, Alexa H.

    2015-01-01

    Sex differences in the oxytocin (OT) system in the brain may explain why OT often regulates social behaviors in sex-specific ways. However, a link between sex differences in the OT system and sex-specific regulation of social behavior has not been tested. Here, we determined whether sex differences in the OT receptor (OTR) or in OT release in the posterior bed nucleus of the stria terminalis (pBNST) mediates sex-specific regulation of social recognition in rats. We recently showed that, compared to female rats, male rats have a three-fold higher OTR binding density in the pBNST, a sexually dimorphic area implicated in the regulation of social behaviors. We now demonstrate that OTR antagonist (5 ng/0.5 μl/side) administration into the pBNST impairs social recognition in both sexes, while OT (100 pg/0.5 μl/side) administration into the pBNST prolongs the duration of social recognition in males only. These effects seem specific to social recognition, as neither treatment altered total social investigation time in either sex. Moreover, baseline OT release in the pBNST, as measured with in vivo microdialysis, did not differ between the sexes. However, males showed higher OT release in the pBNST during social recognition compared to females. These findings suggest a sex-specific role of the OT system in the pBNST in the regulation of social recognition. PMID:26630388

  11. Involvement of the oxytocin system in the bed nucleus of the stria terminalis in the sex-specific regulation of social recognition.

    Science.gov (United States)

    Dumais, Kelly M; Alonso, Andrea G; Immormino, Marisa A; Bredewold, Remco; Veenema, Alexa H

    2016-02-01

    Sex differences in the oxytocin (OT) system in the brain may explain why OT often regulates social behaviors in sex-specific ways. However, a link between sex differences in the OT system and sex-specific regulation of social behavior has not been tested. Here, we determined whether sex differences in the OT receptor (OTR) or in OT release in the posterior bed nucleus of the stria terminalis (pBNST) mediates sex-specific regulation of social recognition in rats. We recently showed that, compared to female rats, male rats have a three-fold higher OTR binding density in the pBNST, a sexually dimorphic area implicated in the regulation of social behaviors. We now demonstrate that OTR antagonist (5 ng/0.5 μl/side) administration into the pBNST impairs social recognition in both sexes, while OT (100 pg/0.5 μl/side) administration into the pBNST prolongs the duration of social recognition in males only. These effects seem specific to social recognition, as neither treatment altered total social investigation time in either sex. Moreover, baseline OT release in the pBNST, as measured with in vivo microdialysis, did not differ between the sexes. However, males showed higher OT release in the pBNST during social recognition compared to females. These findings suggest a sex-specific role of the OT system in the pBNST in the regulation of social recognition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Design, preparation, surface recognition properties, and characteristics of icariin molecularly imprinted polymers

    Directory of Open Access Journals (Sweden)

    Xiaohe Jia

    2015-12-01

    Full Text Available Icariin molecularly imprinted polymers (MIPs were prepared by precipitation polymerization. Prior to the polymerization, computer simulation was performed to sketchily choose the suitable functional monomer and the corresponding polymerization solvent. The optimized synthesis parameters, including the functional monomer acrylamide, the mixture of methanol and acetonitrile (V:V = 3:1 as the polymerization solvent, and the reaction molar ratio (1:6:80 of template molecule, functional monomer and cross-linker, were respectively obtained by single factor analysis and orthogonal design methods. The results of the adsorption experiments showed that the resultant MIPs exhibited good adsorption and recognition abilities to icariin. Scatchard analysis illustrated that the homogeneous binding sites only for icariin molecules were formed in the prepared MIPs.

  13. Deep learning for single-molecule science

    Science.gov (United States)

    Albrecht, Tim; Slabaugh, Gregory; Alonso, Eduardo; Al-Arif, SM Masudur R.

    2017-10-01

    Exploring and making predictions based on single-molecule data can be challenging, not only due to the sheer size of the datasets, but also because a priori knowledge about the signal characteristics is typically limited and poor signal-to-noise ratio. For example, hypothesis-driven data exploration, informed by an expectation of the signal characteristics, can lead to interpretation bias or loss of information. Equally, even when the different data categories are known, e.g., the four bases in DNA sequencing, it is often difficult to know how to make best use of the available information content. The latest developments in machine learning (ML), so-called deep learning (DL) offer interesting, new avenues to address such challenges. In some applications, such as speech and image recognition, DL has been able to outperform conventional ML strategies and even human performance. However, to date DL has not been applied much in single-molecule science, presumably in part because relatively little is known about the ‘internal workings’ of such DL tools within single-molecule science as a field. In this Tutorial, we make an attempt to illustrate in a step-by-step guide how one of those, a convolutional neural network (CNN), may be used for base calling in DNA sequencing applications. We compare it with a SVM as a more conventional ML method, and discuss some of the strengths and weaknesses of the approach. In particular, a ‘deep’ neural network has many features of a ‘black box’, which has important implications on how we look at and interpret data.

  14. Semantic relations differentially impact associative recognition memory: electrophysiological evidence.

    Science.gov (United States)

    Kriukova, Olga; Bridger, Emma; Mecklinger, Axel

    2013-10-01

    Though associative recognition memory is thought to rely primarily on recollection, recent research indicates that familiarity might also make a substantial contribution when to-be-learned items are integrated into a coherent structure by means of an existing semantic relation. It remains unclear how different types of semantic relations, such as categorical (e.g., dancer-singer) and thematic (e.g., dancer-stage) relations might affect associative recognition, however. Using event-related potentials (ERPs), we addressed this question by manipulating the type of semantic link between paired words in an associative recognition memory experiment. An early midfrontal old/new effect, typically linked to familiarity, was observed across the relation types. In contrast, a robust left parietal old/new effect was found in the categorical condition only, suggesting a clear contribution of recollection to associative recognition for this kind of pairs. One interpretation of this pattern is that familiarity was sufficiently diagnostic for associative recognition of thematic relations, which could result from the integrative nature of the thematic relatedness compared to the similarity-based nature of categorical pairs. The present study suggests that the extent to which recollection and familiarity are involved in associative recognition is at least in part determined by the properties of semantic relations between the paired associates. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Speech Recognition

    Directory of Open Access Journals (Sweden)

    Adrian Morariu

    2009-01-01

    Full Text Available This paper presents a method of speech recognition by pattern recognition techniques. Learning consists in determining the unique characteristics of a word (cepstral coefficients by eliminating those characteristics that are different from one word to another. For learning and recognition, the system will build a dictionary of words by determining the characteristics of each word to be used in the recognition. Determining the characteristics of an audio signal consists in the following steps: noise removal, sampling it, applying Hamming window, switching to frequency domain through Fourier transform, calculating the magnitude spectrum, filtering data, determining cepstral coefficients.

  16. Characterization of Heme Proteins Involved in Microbial Exoelectric Activity and Small Molecule-Sensing

    KAUST Repository

    Vogler, Malvina M.

    2018-01-01

    Heme proteins, also termed cytochromes, are a widespread class of metalloproteins containing an Fe-protoporphyrin IX cofactor. They perform numerous functions in nature such as oxygen-transport by hemoglobin, monooxygenation reactions catalyzed by Cytochrome P-450, and electron transfer reactions during photosynthesis. The differences between proteincofactor binding characteristics and the cofactor environment greatly influence the extensive range of functions. In this dissertation, proteins from the Mtr pathway of Shewanella oneidensis are characterized. These c-type cytochromes contain multiple heme cofactors per protein molecule that covalently attach to the protein amino acid sequence and are involved in electron transfer to extracellular metal oxides during anaerobic conditions. Successful recombinant expression of pathway components MtrC and MtrA is achieved in Escherichia coli. Heme-dependent gel staining and UV/Vis spectroscopy show characteristic c-type cytochrome characteristics. Mass spectrometry confirms that the correct extensive post-translational modifications were performed and the ten heme groups were incorporated per protein of MtrC and MtrA and the correct lipid-anchor was attached to extracellular MtrC. Raman spectroscopy measurements of MtrA provide intriguing structural information and highlight the strong influence of the heme cofactors within the protein structure. Next, an Arabidopsis thaliana protein is analyzed. It was previously identified via a motif search of the plant genome, based on conserved residues in the H4 NOX pocket. Here, the incorporation of a heme b cofactor is confirmed. UV/Vis spectroscopy under anaerobic conditions demonstrates reversible binding of nitric oxide to the heme iron and depicts the previously published characteristic absorption maxima for other H-NOX proteins.

  17. Right parietal cortex mediates recognition memory for melodies.

    Science.gov (United States)

    Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

    2015-07-01

    Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  18. Recognition and Toleration

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    Recognition and toleration are ways of relating to the diversity characteristic of multicultural societies. The article concerns the possible meanings of toleration and recognition, and the conflict that is often claimed to exist between these two approaches to diversity. Different forms...... or interpretations of recognition and toleration are considered, confusing and problematic uses of the terms are noted, and the compatibility of toleration and recognition is discussed. The article argues that there is a range of legitimate and importantly different conceptions of both toleration and recognition...

  19. Hydrogen transfer reactions of interstellar Complex Organic Molecules

    Science.gov (United States)

    Álvarez-Barcia, S.; Russ, P.; Kästner, J.; Lamberts, T.

    2018-06-01

    Radical recombination has been proposed to lead to the formation of complex organic molecules (COMs) in CO-rich ices in the early stages of star formation. These COMs can then undergo hydrogen addition and abstraction reactions leading to a higher or lower degree of saturation. Here, we have studied 14 hydrogen transfer reactions for the molecules glyoxal, glycoaldehyde, ethylene glycol, and methylformate and an additional three reactions where CHnO fragments are involved. Over-the-barrier reactions are possible only if tunneling is invoked in the description at low temperature. Therefore the rate constants for the studied reactions are calculated using instanton theory that takes quantum effects into account inherently. The reactions were characterized in the gas phase, but this is expected to yield meaningful results for CO-rich ices due to the minimal alteration of reaction landscapes by the CO molecules. We found that rate constants should not be extrapolated based on the height of the barrier alone, since the shape of the barrier plays an increasingly larger role at decreasing temperature. It is neither possible to predict rate constants based only on considering the type of reaction, the specific reactants and functional groups play a crucial role. Within a single molecule, though, hydrogen abstraction from an aldehyde group seems to be always faster than hydrogen addition to the same carbon atom. Reactions that involve heavy-atom tunneling, e.g., breaking or forming a C-C or C-O bond, have rate constants that are much lower than those where H transfer is involved.

  20. Role of the adhesion molecule F3/Contactin in synaptic plasticity and memory.

    Science.gov (United States)

    Gulisano, Walter; Bizzoca, Antonella; Gennarini, Gianfranco; Palmeri, Agostino; Puzzo, Daniela

    2017-06-01

    Cell adhesion molecules (CAMs) have a pivotal role in building and maintaining synaptic structures during brain development participating in axonal elongation and pathfinding, glial guidance of neuronal migration, as well as myelination. CAMs expression persists in the adult brain particularly in structures undergoing postnatal neurogenesis and involved in synaptic plasticity and memory as the hippocampus. Among the neural CAMs, we have recently focused on F3/Contactin, a glycosylphosphatidyl inositol-anchored glycoprotein belonging to the immunoglobulin superfamily, involved in neuronal development, synaptic maintenance and organization of neuronal networks. Here, we discuss our recent data suggesting that F3/Contactin exerts a role in hippocampal synaptic plasticity and memory in adult and aged mice. In particular, we have studied long-term potentiation (LTP), spatial and object recognition memory, and phosphorylation of the transcription factor cAMP-Responsive-Element Binding protein (CREB) in a transgenic mouse model of F3/Contactin overexpression. We also investigated whether F3/Contactin might influence neuronal apoptosis and the production of amyloid-beta peptide (Aβ), known to be one of the main pathogenetic hallmarks of Alzheimer's disease (AD). In conclusion, a further understanding of F3/Contactin role in synaptic plasticity and memory might have interesting clinical outcomes in cognitive disorders, such as aging and AD, offering innovative therapeutic opportunities. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Double photoionisation spectra of molecules

    CERN Document Server

    Eland, John

    2017-01-01

    This book contains spectra of the doubly charged positive ions (dications) of some 75 molecules, including the major constituents of terrestrial and planetary atmospheres and prototypes of major chemical groups. It is intended to be a new resource for research in all areas of molecular spectroscopy involving high energy environments, both terrestrial and extra-terrestrial. All the spectra have been produced by photoionisation using laboratory lamps or synchrotron radiation and have been measured using the magnetic bottle time-of-flight technique by coincidence detection of correlated electron pairs. Full references to published work on the same species are given, though for several molecules these are the first published spectra. Double ionisation energies are listed and discussed in relation to the molecular electronic structure of the molecules. A full introduction to the field of molecular double ionisation is included and the mechanisms by which double photoionisation can occur are examined in detail. A p...

  2. REAL-TIME FACE RECOGNITION BASED ON OPTICAL FLOW AND HISTOGRAM EQUALIZATION

    Directory of Open Access Journals (Sweden)

    D. Sathish Kumar

    2013-05-01

    Full Text Available Face recognition is one of the intensive areas of research in computer vision and pattern recognition but many of which are focused on recognition of faces under varying facial expressions and pose variation. A constrained optical flow algorithm discussed in this paper, recognizes facial images involving various expressions based on motion vector computation. In this paper, an optical flow computation algorithm which computes the frames of varying facial gestures, and integrating with synthesized image in a probabilistic environment has been proposed. Also Histogram Equalization technique has been used to overcome the effect of illuminations while capturing the input data using camera devices. It also enhances the contrast of the image for better processing. The experimental results confirm that the proposed face recognition system is more robust and recognizes the facial images under varying expressions and pose variations more accurately.

  3. Determination of CFTR densities in erythrocyte plasma membranes using recognition imaging

    International Nuclear Information System (INIS)

    Ebner, Andreas; Hinterdorfer, Peter; Nikova, Dessy; Lange, Tobias; Bruns, Reimer; Oberleithner, Hans; Schillers, Hermann; Haeberle, Johannes; Falk, Sabine; Duebbers, Angelika

    2008-01-01

    CFTR (cystic fibrosis transmembrane conductance regulator) is a cAMP-regulated chloride (Cl - ) channel that plays an important role in salt and fluid movement across epithelia. Cystic fibrosis (CF), the most common genetic disease among Caucasians, is caused by mutations in the gene encoding CFTR. The most predominant mutation, F508del, disturbs CFTR protein trafficking, resulting in a reduced number of CFTR in the plasma membrane. Recent studies indicate that CFTR is not only found in epithelia but also in human erythrocytes. Although considerable attempts have been made to quantify CFTR in cells, conclusions on numbers of CFTR molecules localized in the plasma membrane have been drawn indirectly. AFM has the power to provide the needed information, since both sub-molecular spatial resolution and direct protein recognition via antibody-antigen interaction can be observed. We performed a quantification study of the CFTR copies in erythrocyte membranes at the single molecule level, and compared the difference between healthy donors and CF patients. We detected that the number of CFTR molecules is reduced by 70% in erythrocytes of cystic fibrosis patients

  4. Determination of CFTR densities in erythrocyte plasma membranes using recognition imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ebner, Andreas; Hinterdorfer, Peter [Institute for Biophysics, University of Linz, A-4040 Linz (Austria); Nikova, Dessy; Lange, Tobias; Bruns, Reimer; Oberleithner, Hans; Schillers, Hermann [Institute of Physiology II, University of Muenster, D-48149 Muenster (Germany); Haeberle, Johannes; Falk, Sabine; Duebbers, Angelika [Department of Pediatrics, University Hospitals of Muenster, D-48149 Muenster (Germany)], E-mail: schille@uni-muenster.de

    2008-09-24

    CFTR (cystic fibrosis transmembrane conductance regulator) is a cAMP-regulated chloride (Cl{sup -}) channel that plays an important role in salt and fluid movement across epithelia. Cystic fibrosis (CF), the most common genetic disease among Caucasians, is caused by mutations in the gene encoding CFTR. The most predominant mutation, F508del, disturbs CFTR protein trafficking, resulting in a reduced number of CFTR in the plasma membrane. Recent studies indicate that CFTR is not only found in epithelia but also in human erythrocytes. Although considerable attempts have been made to quantify CFTR in cells, conclusions on numbers of CFTR molecules localized in the plasma membrane have been drawn indirectly. AFM has the power to provide the needed information, since both sub-molecular spatial resolution and direct protein recognition via antibody-antigen interaction can be observed. We performed a quantification study of the CFTR copies in erythrocyte membranes at the single molecule level, and compared the difference between healthy donors and CF patients. We detected that the number of CFTR molecules is reduced by 70% in erythrocytes of cystic fibrosis patients.

  5. The different faces of one’s self: an fMRI study into the recognition of current and past self-facial appearances

    Science.gov (United States)

    Apps, Matthew A. J.; Tajadura-Jiménez, Ana; Turley, Grainne; Tsakiris, Manos

    2013-01-01

    Mirror self-recognition is often considered as an index of self-awareness. Neuroimaging studies have identified a neural circuit specialised for the recognition of one’s own current facial appearance. However, faces change considerably over a lifespan, highlighting the necessity for representations of one’s face to continually be updated. We used fMRI to investigate the different neural circuits involved in the recognition of the childhood and current, adult, faces of one’s self. Participants viewed images of either their own face as it currently looks morphed with the face of a familiar other or their childhood face morphed with the childhood face of the familiar other. Activity in areas which have a generalised selectivity for faces, including the inferior occipital gyrus, the superior parietal lobule and the inferior temporal gyrus, varied with the amount of current self in an image. Activity in areas involved in memory encoding and retrieval, including the hippocampus and the posterior cingulate gyrus, and areas involved in creating a sense of body ownership, including the temporo-parietal junction and the inferior parietal lobule, varied with the amount of childhood self in an image. We suggest that the recognition of one’s own past or present face is underpinned by different cognitive processes in distinct neural circuits. Current self-recognition engages areas involved in perceptual face processing, whereas childhood self-recognition recruits networks involved in body ownership and memory processing. PMID:22940117

  6. Molecular imprinting at walls of silica nanotubes for TNT recognition.

    Science.gov (United States)

    Xie, Chenggen; Liu, Bianhua; Wang, Zhenyang; Gao, Daming; Guan, Guijian; Zhang, Zhongping

    2008-01-15

    This paper reports the molecular imprinting at the walls of highly uniform silica nanotubes for the recognition of 2,4,6-trinitrotoluene (TNT). It has been demonstrated that TNT templates were efficiently imprinted into the matrix of silica through the strong acid-base pairing interaction between TNT and 3-aminopropyltriethoxysilane (APTS). TNT-imprinted silica nanotubes were synthesized by the gelation reaction between APTS and tetraethylorthosilicate (TEOS), selectively occurring at the porous walls of APTS-modified alumina membranes. The removal of the original TNT templates leaves the imprinted cavities with covalently anchored amine groups at the cavity walls. A high density of recognition sites with molecular selectivity to the TNT analyte was created at the wall of silica nanotubes. Furthermore, most of these recognition sites are situated at the inside and outside surfaces of tubular walls and in the proximity of the two surfaces due to the ultrathin wall thickness of only 15 nm, providing a better site accessibility and lower mass-transfer resistance. Therefore, greater capacity and faster kinetics of uptaking target species were achieved. The silica nanotube reported herein is an ideal form of material for imprinting various organic or biological molecules toward applications in chemical/biological sensors and bioassay.

  7. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 14; Issue 12. Molecule Matters van der Waals Molecules - Noble Gas Clusters are London Molecules! E Arunan. Feature Article Volume 14 Issue 12 December 2009 pp 1210-1222 ...

  8. Role of syllable segmentation processes in peripheral word recognition.

    Science.gov (United States)

    Bernard, Jean-Baptiste; Calabrèse, Aurélie; Castet, Eric

    2014-12-01

    Previous studies of foveal visual word recognition provide evidence for a low-level syllable decomposition mechanism occurring during the recognition of a word. We investigated if such a decomposition mechanism also exists in peripheral word recognition. Single words were visually presented to subjects in the peripheral field using a 6° square gaze-contingent simulated central scotoma. In the first experiment, words were either unicolor or had their adjacent syllables segmented with two different colors (color/syllable congruent condition). Reaction times for correct word identification were measured for the two different conditions and for two different print sizes. Results show a significant decrease in reaction time for the color/syllable congruent condition compared with the unicolor condition. A second experiment suggests that this effect is specific to syllable decomposition and results from strategic, presumably involving attentional factors, rather than stimulus-driven control.

  9. Facial emotion recognition in patients with focal and diffuse axonal injury.

    Science.gov (United States)

    Yassin, Walid; Callahan, Brandy L; Ubukata, Shiho; Sugihara, Genichi; Murai, Toshiya; Ueda, Keita

    2017-01-01

    Facial emotion recognition impairment has been well documented in patients with traumatic brain injury. Studies exploring the neural substrates involved in such deficits have implicated specific grey matter structures (e.g. orbitofrontal regions), as well as diffuse white matter damage. Our study aims to clarify whether different types of injuries (i.e. focal vs. diffuse) will lead to different types of impairments on facial emotion recognition tasks, as no study has directly compared these patients. The present study examined performance and response patterns on a facial emotion recognition task in 14 participants with diffuse axonal injury (DAI), 14 with focal injury (FI) and 22 healthy controls. We found that, overall, participants with FI and DAI performed more poorly than controls on the facial emotion recognition task. Further, we observed comparable emotion recognition performance in participants with FI and DAI, despite differences in the nature and distribution of their lesions. However, the rating response pattern between the patient groups was different. This is the first study to show that pure DAI, without gross focal lesions, can independently lead to facial emotion recognition deficits and that rating patterns differ depending on the type and location of trauma.

  10. Multicharged Ion-induced simple molecule fragmentation dynamics; Dynamique de la fragmentation de molecules simples induite par impact d'ion multicharge

    Energy Technology Data Exchange (ETDEWEB)

    Tarisien, M

    2003-10-01

    The aim of this work is to study the dynamics of swift multicharged ion-induced fragmentation of diatomic (CO) and triatomic (CO{sub 2}) molecules. Performed at the GANIL facility, this study used the Recoil Ion Momentum Spectroscopy technique (RIMS), which consists of a time-of-flight mass spectrometer, coupled with a multi-hit capability position sensitive detector (delay line anode). The high-resolution measurement of the kinetic energy distribution released (KER) during the CO fragmentation points out the limitation of the Coulomb Explosion Model, revealing, for example, the di-cation CO{sub 2}{sup +} electronic state contribution in the case of C{sup +}/O{sup +} fragmentation pathway. Furthermore, the multi-ionization cross section dependence with the orientation of the internuclear axis of CO is compared with a geometrical model calculation. Finally, different behaviours are observed for the dissociation dynamics of a triatomic molecule (CO{sub 2}). While triple ionization leads mainly to a synchronous concerted fragmentation dynamics, a weak fraction of dissociating molecule follows a sequential dynamics involving CO{sub 2}{sup +} metastable states. In the case of double ionization, (CO{sub 2}){sup 2+} di-cation dissociation dynamics is asynchronously concerted and has been interpreted using a simple model involving an asymmetrical vibration of the molecule. (author)

  11. Protein-Templated Fragment Ligations-From Molecular Recognition to Drug Discovery.

    Science.gov (United States)

    Jaegle, Mike; Wong, Ee Lin; Tauber, Carolin; Nawrotzky, Eric; Arkona, Christoph; Rademann, Jörg

    2017-06-19

    Protein-templated fragment ligation is a novel concept to support drug discovery and can help to improve the efficacy of protein ligands. Protein-templated fragment ligations are chemical reactions between small molecules ("fragments") utilizing a protein's surface as a reaction vessel to catalyze the formation of a protein ligand with increased binding affinity. The approach exploits the molecular recognition of reactive small-molecule fragments by proteins both for ligand assembly and for the identification of bioactive fragment combinations. In this way, chemical synthesis and bioassay are integrated in one single step. This Review discusses the biophysical basis of reversible and irreversible fragment ligations and gives an overview of the available methods to detect protein-templated ligation products. The chemical scope and recent applications as well as future potential of the concept in drug discovery are reviewed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Muon, positron and antiproton interactions with atoms and molecules

    Energy Technology Data Exchange (ETDEWEB)

    Armour, Edward A G, E-mail: edward.armour@nottingham.ac.u [School of Mathematical Sciences, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2010-04-01

    In this paper, a description is given of some interesting processes involving the interaction of a muon, a positron, or an antiproton with atoms and molecules. The process involving a muon is the resonant formation of the muonic molecular ion, dt{mu}, in the muon catalyzed fusion cycle. In the case of a positron, the process considered is positron annihilation in low-energy positron scattering by the hydrogen molecule. The antiproton is considered as the nucleus of an antihydrogen atom interacting with simple atoms. Attention is given to antiproton annihilation through the strong interaction. An outline is given of proposed tests of fundamental physics to be carried out using antihydrogen.

  13. Recognition of damage-associated, nucleic acid-related molecular patterns during inflammation and vaccination

    Directory of Open Access Journals (Sweden)

    Nao eJounai

    2013-01-01

    Full Text Available All mammalian cells are equipped with large numbers of sensors for protection from various sorts of invaders, who, in turn, are equipped with molecules containing pathogen-associated molecular patterns (PAMPs. Once these sensors recognize non-self antigens containing PAMPs, various physiological responses including inflammation are induced to eliminate the pathogens. However, the host sometimes suffers from chronic infection or continuous injuries, resulting in production of self-molecules containing damage-associated molecular patterns (DAMPs. DAMPs are also responsible for the elimination of pathogens, but promiscuous recognition of DAMPs through sensors against PAMPs has been reported. Accumulation of DAMPs leads to massive inflammation and continuous production of DAMPs; that is, a vicious circle leading to the development of autoimmune disease. From a vaccinological point of view, the accurate recognition of both PAMPs and DAMPs is important for vaccine immunogenicity, because vaccine adjuvants are composed of several PAMPs and/or DAMPs, which are also associated with severe adverse events after vaccination. Here, we review as the roles of PAMPs and DAMPs upon infection with pathogens or inflammation, and the sensors responsible for recognizing them, as well as their relationship with the development of autoimmune disease or the immunogenicity of vaccines.

  14. Slp-76 is a critical determinant of NK cell-mediated recognition of missing-self targets

    Science.gov (United States)

    Lampe, Kristin; Endale, Mehari; Cashman, Siobhan; Fang, Hao; Mattner, Jochen; Hildeman, David; Hoebe, Kasper

    2015-01-01

    Absence of MHC class I expression is an important mechanism by which NK cells recognize a variety of target cells, yet the pathways underlying “missing-self” recognition, including the involvement of activating receptors, remain poorly understood. Using ENU mutagenesis in mice, we identified a germline mutant, designated Ace, with a marked defect in NK cell-mediated recognition and elimination of “missing-self” targets. The causative mutation was linked to chromosome 11 and identified as a missense mutation [Thr428Ile] in the SH2 domain of Slp-76—a critical adapter molecule downstream of ITAM-containing surface receptors. The Slp-76 Ace mutation behaved as a hypomorphic allele—while no major defects were observed in conventional T cell development/function, a marked defect in NK cell-mediated elimination of β2-Microglobulin (β2M)-deficient target cells was observed. Further studies revealed Slp-76 to control NK cell receptor expression and maturation, however, activation of Slp-76ace/ace NK cells through ITAM-containing NK cell receptors or allogeneic/tumor target cells appeared largely unaffected. Imagestream analysis of the NK-β2M−/− target cell synapse, revealed a specific defect in actin recruitment to the conjugate synapse in Slp-76ace/ace NK cells. Overall these studies establish Slp-76 as a critical determinant of NK cell development and NK cell-mediated elimination of missing-self target cells. PMID:25929249

  15. Slp-76 is a critical determinant of NK-cell mediated recognition of missing-self targets.

    Science.gov (United States)

    Lampe, Kristin; Endale, Mehari; Cashman, Siobhan; Fang, Hao; Mattner, Jochen; Hildeman, David; Hoebe, Kasper

    2015-07-01

    Absence of MHC class I expression is an important mechanism by which NK cells recognize a variety of target cells, yet the pathways underlying "missing-self" recognition, including the involvement of activating receptors, remain poorly understood. Using ethyl-N-nitrosourea mutagenesis in mice, we identified a germline mutant, designated Ace, with a marked defect in NK cell mediated recognition and elimination of "missing-self" targets. The causative mutation was linked to chromosome 11 and identified as a missense mutation (Thr428Ile) in the SH2 domain of Slp-76-a critical adapter molecule downstream of ITAM-containing surface receptors. The Slp-76 Ace mutation behaved as a hypomorphic allele-while no major defects were observed in conventional T-cell development/function, a marked defect in NK cell mediated elimination of β2-microglobulin (β2M) deficient target cells was observed. Further studies revealed Slp-76 to control NK-cell receptor expression and maturation; however, activation of Slp-76(ace/ace) NK cells through ITAM-containing NK-cell receptors or allogeneic/tumor target cells appeared largely unaffected. Imagestream analysis of the NK-β2M(-/-) target cell synapse revealed a specific defect in actin recruitment to the conjugate synapse in Slp-76(ace/ace) NK cells. Overall these studies establish Slp-76 as a critical determinant of NK-cell development and NK cell mediated elimination of missing-self target cells in mice. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Paternal Involvement in Child- Rearing Activities: The Perspective of ...

    African Journals Online (AJOL)

    In recognition of the need to widen the scope of fatherhood scholarship, this article centered on examining paternal involvement but in a socio- cultural context and developmental stage that has headed little attention in previous research. An attempt was made to investigate the nature of paternal involvement (ways, desires ...

  17. Mapping the Small Molecule Interactome by Mass Spectrometry.

    Science.gov (United States)

    Flaxman, Hope A; Woo, Christina M

    2018-01-16

    Mapping small molecule interactions throughout the proteome provides the critical structural basis for functional analysis of their impact on biochemistry. However, translation of mass spectrometry-based proteomics methods to directly profile the interaction between a small molecule and the whole proteome is challenging because of the substoichiometric nature of many interactions, the diversity of covalent and noncovalent interactions involved, and the subsequent computational complexity associated with their spectral assignment. Recent advances in chemical proteomics have begun fill this gap to provide a structural basis for the breadth of small molecule-protein interactions in the whole proteome. Innovations enabling direct characterization of the small molecule interactome include faster, more sensitive instrumentation coupled to chemical conjugation, enrichment, and labeling methods that facilitate detection and assignment. These methods have started to measure molecular interaction hotspots due to inherent differences in local amino acid reactivity and binding affinity throughout the proteome. Measurement of the small molecule interactome is producing structural insights and methods for probing and engineering protein biochemistry. Direct structural characterization of the small molecule interactome is a rapidly emerging area pushing new frontiers in biochemistry at the interface of small molecules and the proteome.

  18. Using eye movements as an index of implicit face recognition in autism spectrum disorder.

    Science.gov (United States)

    Hedley, Darren; Young, Robyn; Brewer, Neil

    2012-10-01

    Individuals with an autism spectrum disorder (ASD) typically show impairment on face recognition tasks. Performance has usually been assessed using overt, explicit recognition tasks. Here, a complementary method involving eye tracking was used to examine implicit face recognition in participants with ASD and in an intelligence quotient-matched non-ASD control group. Differences in eye movement indices between target and foil faces were used as an indicator of implicit face recognition. Explicit face recognition was assessed using old-new discrimination and reaction time measures. Stimuli were faces of studied (target) or unfamiliar (foil) persons. Target images at test were either identical to the images presented at study or altered by changing the lighting, pose, or by masking with visual noise. Participants with ASD performed worse than controls on the explicit recognition task. Eye movement-based measures, however, indicated that implicit recognition may not be affected to the same degree as explicit recognition. Autism Res 2012, 5: 363-379. © 2012 International Society for Autism Research, Wiley Periodicals, Inc. © 2012 International Society for Autism Research, Wiley Periodicals, Inc.

  19. fMRI characterization of visual working memory recognition.

    Science.gov (United States)

    Rahm, Benjamin; Kaiser, Jochen; Unterrainer, Josef M; Simon, Juliane; Bledowski, Christoph

    2014-04-15

    Encoding and maintenance of information in visual working memory have been extensively studied, highlighting the crucial and capacity-limiting role of fronto-parietal regions. In contrast, the neural basis of recognition in visual working memory has remained largely unspecified. Cognitive models suggest that recognition relies on a matching process that compares sensory information with the mental representations held in memory. To characterize the neural basis of recognition we varied both the need for recognition and the degree of similarity between the probe item and the memory contents, while independently manipulating memory load to produce load-related fronto-parietal activations. fMRI revealed a fractionation of working memory functions across four distributed networks. First, fronto-parietal regions were activated independent of the need for recognition. Second, anterior parts of load-related parietal regions contributed to recognition but their activations were independent of the difficulty of matching in terms of sample-probe similarity. These results argue against a key role of the fronto-parietal attention network in recognition. Rather the third group of regions including bilateral temporo-parietal junction, posterior cingulate cortex and superior frontal sulcus reflected demands on matching both in terms of sample-probe-similarity and the number of items to be compared. Also, fourth, bilateral motor regions and right superior parietal cortex showed higher activation when matching provided clear evidence for a decision. Together, the segregation between the well-known fronto-parietal activations attributed to attentional operations in working memory from those regions involved in matching supports the theoretical view of separable attentional and mnemonic contributions to working memory. Yet, the close theoretical and empirical correspondence to perceptual decision making may call for an explicit consideration of decision making mechanisms in

  20. Dignity in health-care: a critical exploration using feminism and theories of recognition.

    Science.gov (United States)

    Aranda, Kay; Jones, Andrea

    2010-09-01

    Growing concerns over undignified health-care has meant the concept of dignity is currently much discussed in the British National Health Service. This has led to a number of policies attempting to reinstate dignity as a core ethical value governing nursing practice and health-care provision. Yet these initiatives continue to draw upon a concept of dignity which remains reliant upon a depoliticised, ahistorical and decontexualised subject. In this paper, we argue the need to revise the dignity debate through the lens of feminism and theories of recognition. Postmodern feminist theories provide major challenges to what remain dominant liberal approaches as they pay attention to the contingent, reflexive, and affective aspects of care work. Theories of recognition provide a further critical resource for understanding how moral obligations and responsibilities towards others and our public and private responses to difference arise. This re-situates dignity as a highly contested and politicised concept involving complex moral deliberations and diverse political claims of recognition. The dignity debate is thus moved beyond simplistic rational injunctions to care, or to care more, and towards critical discussions of complex politicised, moral practices infused with power that involve the recognition of difference in health-care.

  1. Re-thinking employee recognition: understanding employee experiences of recognition

    OpenAIRE

    Smith, Charlotte

    2013-01-01

    Despite widespread acceptance of the importance of employee recognition for both individuals and organisations and evidence of its increasing use in organisations, employee recognition has received relatively little focused attention from academic researchers. Particularly lacking is research exploring the lived experience of employee recognition and the interpretations and meanings which individuals give to these experiences. Drawing on qualitative interviews conducted as part of my PhD rese...

  2. Involvement of lipid-protein complexes in plant-microorganism interactions

    Directory of Open Access Journals (Sweden)

    Blein Jean-Pierre

    2002-01-01

    Full Text Available Increasing concerns about the environmental impact of modern agricultural have prompted research for alternate practices to pesticide treatments, notably using plant defense mechanisms. Thus, isolation and characterization of plant defense elicitors have been the main step of studies in many groups. Moreover, in the global concept of interactions between organisms and their environment, a major concern is to discriminate recognition between exogenous and endogenous signals, notably during pathogenic or allergenic interactions involving small proteins, such as elicitins or lipid transfer proteins (LTPs. Elicitins and lipid transfer proteins (LTP are both able to load and transfer lipidic molecules and share some structural and functional properties. While elicitins are known as elicitors of plant defense mechanisms, the biological function of LTPs is still an enigma. They are ubiquitous plant proteins able to load and transfer hydrophobic molecules such as fatty acids or phospholipids. Among them, LTPs1 (type 1 lipid transfer proteins constitute a multigenic family of secreted plant lipid binding proteins that are constitutively expressed in specific tissues and/or induced in response to biotic and abiotic stress (for reviews [1-4]. Their biological function is still unknown, even if some data provide arguments for a role of these proteins in the assembly of extracellular hydrophobic polymers (i.e., cutin and suberin [2, 4] and/or in plant defense against fungal pathogens [1, 3]. Beside their involvement in plant defense, LTPs1 are also known to be pan-allergens of plant-derived foods [5]. Finally, the discovery of the sterol carrier-properties of elicitins has opened new perspectives dealing with the relationship between this function and the elicitor activity of these small cystein-rich proteins. Nevertheless, this elicitor activity is restrained to few plant species, and thus does not appear in accordance with a universal lipid transfer

  3. Mechanistic pathways of recognition of a solvent-inaccessible cavity of protein by a ligand

    Science.gov (United States)

    Mondal, Jagannath; Pandit, Subhendu; Dandekar, Bhupendra; Vallurupalli, Pramodh

    One of the puzzling questions in the realm of protein-ligand recognition is how a solvent-inaccessible hydrophobic cavity of a protein gets recognized by a ligand. We address the topic by simulating, for the first time, the complete binding process of benzene from aqueous media to the well-known buried cavity of L99A T4 Lysozyme at an atomistic resolution. Our multiple unbiased microsecond-long trajectories, which were completely blind to the location of target binding site, are able to unequivocally identify the kinetic pathways along which benzene molecule meanders across the solvent and protein and ultimately spontaneously recognizes the deeply buried cavity of L99A T4 Lysozyme at an accurate precision. Our simulation, combined with analysis based on markov state model and free energy calculation, reveals that there are more than one distinct ligand binding pathways. Intriguingly, each of the identified pathways involves the transient opening of a channel of the protein prior to ligand binding. The work will also decipher rich mechanistic details on unbinding kinetics of the ligand as obtained from enhanced sampling techniques.

  4. The Role of Sensory-Motor Information in Object Recognition: Evidence from Category-Specific Visual Agnosia

    Science.gov (United States)

    Wolk, D.A.; Coslett, H.B.; Glosser, G.

    2005-01-01

    The role of sensory-motor representations in object recognition was investigated in experiments involving AD, a patient with mild visual agnosia who was impaired in the recognition of visually presented living as compared to non-living entities. AD named visually presented items for which sensory-motor information was available significantly more…

  5. Cardiac tamponade preceding skin involvement in systemic sclerosis

    Directory of Open Access Journals (Sweden)

    L. Bozzola

    2011-09-01

    Full Text Available The frequency of pericardial involvement in Systemic Sclerosis (SSc is high on autoptic or echocardiographic studies, but the clinical recognition of pericarditis with or without effusion is rare. We describe a case of a 71-year-old female with no previous history of heart disease, who presented with a large pericardial effusion and tamponade that required pericardial drain. She had suffered from Raynaud’s phenomenon since 25 years. Six weeks after hospital discharge she complained of skin hardening on left leg. Pericardial tamponade is a very rare manifestation of SSc and occurs both early or late in the course of the disease, but in our case it preceded the recognition of scleroderma. We have only identified two other cases of pericardial effusion preceding cutaneous involvement in scleroderma.

  6. Use of the recognition heuristic depends on the domain's recognition validity, not on the recognition validity of selected sets of objects.

    Science.gov (United States)

    Pohl, Rüdiger F; Michalkiewicz, Martha; Erdfelder, Edgar; Hilbig, Benjamin E

    2017-07-01

    According to the recognition-heuristic theory, decision makers solve paired comparisons in which one object is recognized and the other not by recognition alone, inferring that recognized objects have higher criterion values than unrecognized ones. However, success-and thus usefulness-of this heuristic depends on the validity of recognition as a cue, and adaptive decision making, in turn, requires that decision makers are sensitive to it. To this end, decision makers could base their evaluation of the recognition validity either on the selected set of objects (the set's recognition validity), or on the underlying domain from which the objects were drawn (the domain's recognition validity). In two experiments, we manipulated the recognition validity both in the selected set of objects and between domains from which the sets were drawn. The results clearly show that use of the recognition heuristic depends on the domain's recognition validity, not on the set's recognition validity. In other words, participants treat all sets as roughly representative of the underlying domain and adjust their decision strategy adaptively (only) with respect to the more general environment rather than the specific items they are faced with.

  7. Museums, minorities and recognition: memories of North Africa in contemporary France

    Directory of Open Access Journals (Sweden)

    Mary Stevens

    2007-03-01

    Full Text Available This article uses a case study from the Musée dauphinois in Grenoble, France to explore the way museums are called upon to act as ‘authorities of recognition’ for minority communities. Studies of public recognition have often focused on political and legal measures, such as reparations, rather than considering questions of public representation. In satisfying demands for recognition on the part of minority groups do museums contribute to social cohesion or do they generate competition between groups that may heighten existing tensions? This question is particularly pertinent in the French case where the philosophy of republican universalism traditionally discourages acknowledgement of group identities. Drawing on work on recognition by Feuchtwang and Dufoix this article argues that a more complex model of recognition needs to be elaborated for museums in order to take into account the multiple actors involved in the development and reception of exhibitions.

  8. Multiple proteins of White spot syndrome virus involved in ...

    Indian Academy of Sciences (India)

    The recognition and attachment of virus to its host cell surface is a critical step for viral infection. Recent research revealed that -integrin was involved in White spot syndrome virus (WSSV) infection. In this study, the interaction of -integrin with structure proteins of WSSV and motifs involved in WSSV infection was ...

  9. Self-organized lattice of ordered quantum dot molecules

    International Nuclear Information System (INIS)

    Lippen, T. von; Noetzel, R.; Hamhuis, G.J.; Wolter, J.H.

    2004-01-01

    Ordered groups of InAs quantum dots (QDs), lateral QD molecules, are created by self-organized anisotropic strain engineering of a (In,Ga)As/GaAs superlattice (SL) template on GaAs (311)B in molecular-beam epitaxy. During stacking, the SL template self-organizes into a two-dimensionally ordered strain modulated network on a mesoscopic length scale. InAs QDs preferentially grow on top of the nodes of the network due to local strain recognition. The QDs form a lattice of separated groups of closely spaced ordered QDs whose number can be controlled by the GaAs separation layer thickness on top of the SL template. The QD groups exhibit excellent optical properties up to room temperature

  10. Effects of the medial or basolateral amygdala upon social anxiety and social recognition in mice.

    Science.gov (United States)

    Wang, Yu; Zhao, Shanshan; Liu, Xu; Fu, Qunying

    2014-01-01

    Though social anxiety and social recognition have been studied extensively, the roles of the medial or basolateral amygdala in the control of social anxiety and social recognition remain to be determined. This study investigated the effects of excitotoxic bilateral medial or basolateral amygdala lesions upon social anxiety and social recognition in-mice. Animals at 9 weeks of age were given bilateral medial or basolateral amygdala lesions via infusion of N-methyl- D-aspartate and then were used for behavioral tests: anxiety-related tests (including open-field test, light-dark test, and elevated-plus maze test), social behavior test in a novel environment, social recognition test, and flavor recognition test. Medial or basolateral amygdala-lesioned mice showed lower levels of anxiety and increased social behaviors in a novel environment. Destruction of the medial or basolateral amygdala neurons impaired social recognition but not flavor recognition. The medial or basolateral amygdala is involved in the control of anxiety-related behavior (social anxiety and social behaviors) in mice. Moreover, both the medial and the basolateral amygdala are essential for social recognition but not flavor recognition in mice.

  11. Ear recognition from one sample per person.

    Directory of Open Access Journals (Sweden)

    Long Chen

    Full Text Available Biometrics has the advantages of efficiency and convenience in identity authentication. As one of the most promising biometric-based methods, ear recognition has received broad attention and research. Previous studies have achieved remarkable performance with multiple samples per person (MSPP in the gallery. However, most conventional methods are insufficient when there is only one sample per person (OSPP available in the gallery. To solve the OSPP problem by maximizing the use of a single sample, this paper proposes a hybrid multi-keypoint descriptor sparse representation-based classification (MKD-SRC ear recognition approach based on 2D and 3D information. Because most 3D sensors capture 3D data accessorizing the corresponding 2D data, it is sensible to use both types of information. First, the ear region is extracted from the profile. Second, keypoints are detected and described for both the 2D texture image and 3D range image. Then, the hybrid MKD-SRC algorithm is used to complete the recognition with only OSPP in the gallery. Experimental results on a benchmark dataset have demonstrated the feasibility and effectiveness of the proposed method in resolving the OSPP problem. A Rank-one recognition rate of 96.4% is achieved for a gallery of 415 subjects, and the time involved in the computation is satisfactory compared to conventional methods.

  12. Ear recognition from one sample per person.

    Science.gov (United States)

    Chen, Long; Mu, Zhichun; Zhang, Baoqing; Zhang, Yi

    2015-01-01

    Biometrics has the advantages of efficiency and convenience in identity authentication. As one of the most promising biometric-based methods, ear recognition has received broad attention and research. Previous studies have achieved remarkable performance with multiple samples per person (MSPP) in the gallery. However, most conventional methods are insufficient when there is only one sample per person (OSPP) available in the gallery. To solve the OSPP problem by maximizing the use of a single sample, this paper proposes a hybrid multi-keypoint descriptor sparse representation-based classification (MKD-SRC) ear recognition approach based on 2D and 3D information. Because most 3D sensors capture 3D data accessorizing the corresponding 2D data, it is sensible to use both types of information. First, the ear region is extracted from the profile. Second, keypoints are detected and described for both the 2D texture image and 3D range image. Then, the hybrid MKD-SRC algorithm is used to complete the recognition with only OSPP in the gallery. Experimental results on a benchmark dataset have demonstrated the feasibility and effectiveness of the proposed method in resolving the OSPP problem. A Rank-one recognition rate of 96.4% is achieved for a gallery of 415 subjects, and the time involved in the computation is satisfactory compared to conventional methods.

  13. Neural Mechanism for Mirrored Self-face Recognition.

    Science.gov (United States)

    Sugiura, Motoaki; Miyauchi, Carlos Makoto; Kotozaki, Yuka; Akimoto, Yoritaka; Nozawa, Takayuki; Yomogida, Yukihito; Hanawa, Sugiko; Yamamoto, Yuki; Sakuma, Atsushi; Nakagawa, Seishu; Kawashima, Ryuta

    2015-09-01

    Self-face recognition in the mirror is considered to involve multiple processes that integrate 2 perceptual cues: temporal contingency of the visual feedback on one's action (contingency cue) and matching with self-face representation in long-term memory (figurative cue). The aim of this study was to examine the neural bases of these processes by manipulating 2 perceptual cues using a "virtual mirror" system. This system allowed online dynamic presentations of real-time and delayed self- or other facial actions. Perception-level processes were identified as responses to only a single perceptual cue. The effect of the contingency cue was identified in the cuneus. The regions sensitive to the figurative cue were subdivided by the response to a static self-face, which was identified in the right temporal, parietal, and frontal regions, but not in the bilateral occipitoparietal regions. Semantic- or integration-level processes, including amodal self-representation and belief validation, which allow modality-independent self-recognition and the resolution of potential conflicts between perceptual cues, respectively, were identified in distinct regions in the right frontal and insular cortices. The results are supportive of the multicomponent notion of self-recognition and suggest a critical role for contingency detection in the co-emergence of self-recognition and empathy in infants. © The Author 2014. Published by Oxford University Press.

  14. Human NKG2D-ligands: cell biology strategies to ensure immune recognition

    Directory of Open Access Journals (Sweden)

    Lola eFernández-Messina

    2012-09-01

    Full Text Available Immune recognition mediated by the activating receptor NKG2D plays an important role for the elimination of stressed cells, including tumours and virus-infected cells. On the other hand, the ligands for NKG2D can also be shed into the sera of cancer patients where they weaken the immune response by downmodulating the receptor on effector cells, mainly NK and T cells. Although both families of NKG2D-ligands, MICA/B and ULBPs, are related to MHC molecules and their expression is increased after stress, many differences are observed in terms of their biochemical properties and cell trafficking. In this paper, we summarise the variety of NKG2D-ligands and propose that selection pressure has driven evolution of diversity in their trafficking and shedding, but not receptor binding affinity. However, it is also possible to identify functional properties common to individual ULBP molecules and MICA/B alleles, but not generally conserved within the MIC or ULBP families. These characteristics likely represent examples of convergent evolution for efficient immune recognition, but are also attractive targets for pathogen immune evasion strategies. Categorization of NKG2D-ligands according to their biological features, rather than their genetic family, may help to achieve a better understanding of NKG2D-ligand association with disease.

  15. Graphical symbol recognition

    OpenAIRE

    K.C. , Santosh; Wendling , Laurent

    2015-01-01

    International audience; The chapter focuses on one of the key issues in document image processing i.e., graphical symbol recognition. Graphical symbol recognition is a sub-field of a larger research domain: pattern recognition. The chapter covers several approaches (i.e., statistical, structural and syntactic) and specially designed symbol recognition techniques inspired by real-world industrial problems. It, in general, contains research problems, state-of-the-art methods that convey basic s...

  16. Molecule Matters van der Waals Molecules

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 15; Issue 7. Molecule Matters van der Waals Molecules - Rg•••HF Complexes are Debye Molecules! E Arunan. Feature Article Volume 15 Issue 7 July 2010 pp 667-674. Fulltext. Click here to view fulltext PDF. Permanent link:

  17. Bacteroides species produce Vibrio harveyi autoinducer 2-related molecules.

    Science.gov (United States)

    Antunes, Luis Caetano Martha; Ferreira, Lívia Queiroz; Ferreira, Eliane Oliveira; Miranda, Karla Rodrigues; Avelar, Kátia Eliane Santos; Domingues, Regina Maria Cavalcanti Pilotto; Ferreira, Maria Candida de Souza

    2005-10-01

    Quorum sensing is a density-dependent gene regulation mechanism that has been described in many bacterial species in the last decades. Bacteria that use quorum sensing as part of their gene regulation circuits produce molecules called autoinducers that accumulate in the environment and activate target genes in a quorum-dependent way. Some specific clues led us to hypothesize that Bacteroides species can produce autoinducers and possess a quorum sensing system. First, Bacteroides are anaerobic bacteria that are frequently involved in polymicrobial infections. These infections often involve Pseudomonas aeruginosa and Staphylococcus aureus, two of the best understood examples of bacteria that employ quorum sensing systems as part of their pathogenesis. Also, studies have detected the presence of a quorum sensing gene involved in the production of autoinducers in Porphyromonas gingivalis, a species closely related to the Bacteroides genus. These and other evidences prompted us to investigate if Bacteroides strains could produce autoinducer molecules that could be detected by a Vibrio harveyi reporter system. In this paper, we show that supernatants of B. fragilis, B. vulgatus and B. distasonis strains are able to stimulate the V. harveyi quorum sensing system 2. Also, we were able to demonstrate that the stimulation detected is due to the production of autoinducer molecules and not the growth of reporter strains after addition of supernatant. Moreover, the phenomenon observed does not seem to represent the degradation of repressors possibly present in the culture medium used. We could also amplify bands from some of the strains tested using primers designed to the luxS gene of Escherichia coli. Altogether, our results show that B. fragilis, B. vulgatus and B. distasonis (but possibly some other species) can produce V. harveyi autoinducer 2-related molecules. However, the role of such molecules in the biology of these organisms remains unknown.

  18. Receiver Operating Characteristics (ROCs) in Recognition Memory: A Review

    Science.gov (United States)

    Yonelinas, Andrew P.; Parks, Colleen M.

    2007-01-01

    Receiver operating characteristic (ROC) analysis is being used increasingly to examine the memory processes underlying recognition memory. The authors discuss the methodological issues involved in conducting and analyzing ROC results, describe the various models that have been developed to account for these results, review the behavioral empirical…

  19. Selective host molecules obtained by dynamic adaptive chemistry.

    Science.gov (United States)

    Matache, Mihaela; Bogdan, Elena; Hădade, Niculina D

    2014-02-17

    Up till 20 years ago, in order to endow molecules with function there were two mainstream lines of thought. One was to rationally design the positioning of chemical functionalities within candidate molecules, followed by an iterative synthesis-optimization process. The second was the use of a "brutal force" approach of combinatorial chemistry coupled with advanced screening for function. Although both methods provided important results, "rational design" often resulted in time-consuming efforts of modeling and synthesis only to find that the candidate molecule was not performing the designed job. "Combinatorial chemistry" suffered from a fundamental limitation related to the focusing of the libraries employed, often using lead compounds that limit its scope. Dynamic constitutional chemistry has developed as a combination of the two approaches above. Through the rational use of reversible chemical bonds together with a large plethora of precursor libraries, one is now able to build functional structures, ranging from quite simple molecules up to large polymeric structures. Thus, by introduction of the dynamic component within the molecular recognition processes, a new perspective of deciphering the world of the molecular events has aroused together with a new field of chemistry. Since its birth dynamic constitutional chemistry has continuously gained attention, in particular due to its ability to easily create from scratch outstanding molecular structures as well as the addition of adaptive features. The fundamental concepts defining the dynamic constitutional chemistry have been continuously extended to currently place it at the intersection between the supramolecular chemistry and newly defined adaptive chemistry, a pivotal feature towards evolutive chemistry. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Component Pin Recognition Using Algorithms Based on Machine Learning

    Science.gov (United States)

    Xiao, Yang; Hu, Hong; Liu, Ze; Xu, Jiangchang

    2018-04-01

    The purpose of machine vision for a plug-in machine is to improve the machine’s stability and accuracy, and recognition of the component pin is an important part of the vision. This paper focuses on component pin recognition using three different techniques. The first technique involves traditional image processing using the core algorithm for binary large object (BLOB) analysis. The second technique uses the histogram of oriented gradients (HOG), to experimentally compare the effect of the support vector machine (SVM) and the adaptive boosting machine (AdaBoost) learning meta-algorithm classifiers. The third technique is the use of an in-depth learning method known as convolution neural network (CNN), which involves identifying the pin by comparing a sample to its training. The main purpose of the research presented in this paper is to increase the knowledge of learning methods used in the plug-in machine industry in order to achieve better results.

  1. Dust-forming molecules in VY Canis Majoris (and Betelgeuse)

    Science.gov (United States)

    Kamiński, T.; Gottlieb, C. A.; Schmidt, M. R.; Patel, N. A.; Young, K. H.; Menten, K. M.; Brünken, S.; Müller, H. S. P.; Winters, J. M.; McCarthy, M. C.

    2013-05-01

    The formation of inorganic dust in circumstellar environments of evolved stars is poorly understood. Spectra of molecules thought to be most important for the nucleation, i.e. AlO, TiO, and TiO2, have been recently detected in the red supergiant VY CMa. These molecules are effectively formed in VY CMa and the observations suggest that non-equilibrium chemistry must be involved in their formation and nucleation into dust. In addition to exploring the recent observations of VY CMa, we briefly discuss the possibility of detecting these molecules in the "dust-poor" circumstellar environment of Betelgeuse.

  2. Automatic target recognition performance losses in the presence of atmospheric and camera effects

    Science.gov (United States)

    Chen, Xiaohan; Schmid, Natalia A.

    2010-04-01

    The importance of networked automatic target recognition systems for surveillance applications is continuously increasing. Because of the requirement of a low cost and limited payload, these networks are traditionally equipped with lightweight, low-cost sensors such as electro-optical (EO) or infrared sensors. The quality of imagery acquired by these sensors critically depends on the environmental conditions, type and characteristics of sensors, and absence of occluding or concealing objects. In the past, a large number of efficient detection, tracking, and recognition algorithms have been designed to operate on imagery of good quality. However, detection and recognition limits under nonideal environmental and/or sensor-based distortions have not been carefully evaluated. We introduce a fully automatic target recognition system that involves a Haar-based detector to select potential regions of interest within images, performs adjustment of detected regions, segments potential targets using a region-based approach, identifies targets using Bessel K form-based encoding, and performs clutter rejection. We investigate the effects of environmental and camera conditions on target detection and recognition performance. Two databases are involved. One is a simulated database generated using a 3-D tool. The other database is formed by imaging 10 die-cast models of military vehicles from different elevation and orientation angles. The database contains imagery acquired both indoors and outdoors. The indoors data set is composed of clear and distorted images. The distortions include defocus blur, sided illumination, low contrast, shadows, and occlusions. All images in this database, however, have a uniform (blue) background. The indoors database is applied to evaluate the degradations of recognition performance due to camera and illumination effects. The database collected outdoors includes a real background and is much more complex to process. The numerical results

  3. Comparison of emotion recognition from facial expression and music.

    Science.gov (United States)

    Gaspar, Tina; Labor, Marina; Jurić, Iva; Dumancić, Dijana; Ilakovac, Vesna; Heffer, Marija

    2011-01-01

    The recognition of basic emotions in everyday communication involves interpretation of different visual and auditory clues. The ability to recognize emotions is not clearly determined as their presentation is usually very short (micro expressions), whereas the recognition itself does not have to be a conscious process. We assumed that the recognition from facial expressions is selected over the recognition of emotions communicated through music. In order to compare the success rate in recognizing emotions presented as facial expressions or in classical music works we conducted a survey which included 90 elementary school and 87 high school students from Osijek (Croatia). The participants had to match 8 photographs of different emotions expressed on the face and 8 pieces of classical music works with 8 offered emotions. The recognition of emotions expressed through classical music pieces was significantly less successful than the recognition of emotional facial expressions. The high school students were significantly better at recognizing facial emotions than the elementary school students, whereas girls were better than boys. The success rate in recognizing emotions from music pieces was associated with higher grades in mathematics. Basic emotions are far better recognized if presented on human faces than in music, possibly because the understanding of facial emotions is one of the oldest communication skills in human society. Female advantage in emotion recognition was selected due to the necessity of their communication with the newborns during early development. The proficiency in recognizing emotional content of music and mathematical skills probably share some general cognitive skills like attention, memory and motivation. Music pieces were differently processed in brain than facial expressions and consequently, probably differently evaluated as relevant emotional clues.

  4. Recognition rights, mental health consumers and reconstructive cultural semantics

    Directory of Open Access Journals (Sweden)

    Radden Jennifer H

    2012-01-01

    Full Text Available Abstract Introduction Those in mental health-related consumer movements have made clear their demands for humane treatment and basic civil rights, an end to stigma and discrimination, and a chance to participate in their own recovery. But theorizing about the politics of recognition, 'recognition rights' and epistemic justice, suggests that they also have a stake in the broad cultural meanings associated with conceptions of mental health and illness. Results First person accounts of psychiatric diagnosis and mental health care (shown here to represent 'counter stories' to the powerful 'master narrative' of biomedical psychiatry, offer indications about how experiences of mental disorder might be reframed and redefined as part of efforts to acknowledge and honor recognition rights and epistemic justice. However, the task of cultural semantics is one for the entire culture, not merely consumers. These new meanings must be negotiated. When they are not the result of negotiation, group-wrought definitions risk imposing a revision no less constraining than the mis-recognizing one it aims to replace. Contested realities make this a challenging task when it comes to cultural meanings about mental disorder. Examples from mental illness memoirs about two contested realities related to psychosis are examined here: the meaninglessness of symptoms, and the role of insight into illness. They show the magnitude of the challenge involved - for consumers, practitioners, and the general public - in the reconstruction of these new meanings and realities. Conclusion To honor recognition rights and epistemic justice acknowledgement must be made of the heterogeneity of the effects of, and of responses to, psychiatric diagnosis and care, and the extent of the challenge of the reconstructive cultural semantics involved.

  5. Expression of major histocompatibility complex class II and costimulatory molecules in oral carcinomas in vitro.

    Science.gov (United States)

    Villarroel-Dorrego, Mariana; Speight, Paul M; Barrett, A William

    2005-01-01

    Recognition in the 1980 s that keratinocytes can express class II molecules of the Major Histocompatibility Complex (MHC) first raised the possibility that these cells might have an immunological function, and may even act as antigen presenting cells (APC). For effective T lymphocyte activation, APC require, in addition to MHC II, appropriate costimulatory signals. The aim of this study was to determine the expression of MHC class II and the co-stimulatory molecules CD40, CD80 and CD86 in keratinocytes derived from healthy oral mucosa and oral carcinomas. Using flow cytometry, it was confirmed that oral keratinocytes, switch on, expression of MHC class II molecules after stimulation with IFNgamma in vitro. All keratinocyte lines expressed CD40 constitutively; by contrast, CD80 and CD86 were universally absent. Loss of CD80 and CD86 may be one means whereby tumours escape immunological surveillance.

  6. In search of a recognition memory engram

    Science.gov (United States)

    Brown, M.W.; Banks, P.J.

    2015-01-01

    A large body of data from human and animal studies using psychological, recording, imaging, and lesion techniques indicates that recognition memory involves at least two separable processes: familiarity discrimination and recollection. Familiarity discrimination for individual visual stimuli seems to be effected by a system centred on the perirhinal cortex of the temporal lobe. The fundamental change that encodes prior occurrence within the perirhinal cortex is a reduction in the responses of neurones when a stimulus is repeated. Neuronal network modelling indicates that a system based on such a change in responsiveness is potentially highly efficient in information theoretic terms. A review is given of findings indicating that perirhinal cortex acts as a storage site for recognition memory of objects and that such storage depends upon processes producing synaptic weakening. PMID:25280908

  7. Molecular self assembly and chiral recognition of copper octacyanophthalocyanine on Au(111): Interplay of intermolecular and molecule-substrate interactions.

    Science.gov (United States)

    Sk, Rejaul; Dhara, Barun; Miller, Joel; Deshpande, Aparna

    Submolecular resolution scanning tunneling microscopy (STM) of copper octacyanophthalocyanine, CuPc(CN)8, at 77 K demonstrates that these achiral molecules form a two dimensional (2D) tetramer-based self-assembly upon evaporation onto an atomically flat Au(111) substrate. They assemble in two different structurally chiral configurations upon adsorption on Au(111). Scanning tunneling spectroscopy (STS),acquired at 77 K, unveils the HOMO and LUMO energy levels of this self-assembly. Voltage dependent STM images show that each molecule in both the structurally chiral configurations individually becomes chiral by breaking the mirror symmetry due to the enhanced intermolecular dipolar coupling interaction at the LUMO energy while the individual molecules remain achiral at the HOMO energy and within the HOMO-LUMO gap. At the LUMO energy, the handedness of the each chiral molecule is decided by the direction of the dipolar coupling interaction in the tetramer unit cell. This preference for LUMO energy indicates that this chirality is purely electronic in nature and it manifests on top of the organizational chirality that is present in the self-assembly independent of the orbital energy. Supported by IISER Pune and DAE-BRNS, India (Project No. 2011/20/37C/17/BRNS).

  8. Comparison of crisp and fuzzy character networks in handwritten word recognition

    Science.gov (United States)

    Gader, Paul; Mohamed, Magdi; Chiang, Jung-Hsien

    1992-01-01

    Experiments involving handwritten word recognition on words taken from images of handwritten address blocks from the United States Postal Service mailstream are described. The word recognition algorithm relies on the use of neural networks at the character level. The neural networks are trained using crisp and fuzzy desired outputs. The fuzzy outputs were defined using a fuzzy k-nearest neighbor algorithm. The crisp networks slightly outperformed the fuzzy networks at the character level but the fuzzy networks outperformed the crisp networks at the word level.

  9. An 8-year longitudinal study of mirror self-recognition in chimpanzees (Pan troglodytes).

    Science.gov (United States)

    de Veer, Monique W; Gallup, Gordon G; Theall, Laura A; van den Bos, Ruud; Povinelli, Daniel J

    2003-01-01

    In a previous cross-sectional study of mirror self-recognition involving 92 chimpanzees, Povinelli et al. [Journal of Comparative Psychology 107 (1993) 347] reported a peak in the proportion of animals exhibiting self-recognition in the adolescent/young adult sample (8-15 years), with 75% being classified as positive. In contrast, only 26% of the older animals (16-39 years) were classified as positive, suggesting a marked decline in self-recognition in middle to late adulthood. In the present study, all of the chimpanzees from the 8-15-year-old group in the Povinelli et al. study (n=12) were again tested for self-recognition, 8 years later. Using the same criteria, 67% of the animals were classified the same. Although a higher proportion of the adult animals in this study (50%) exhibited self-recognition than would be inferred on the basis of the previous study (25%), all changes in self-recognition status were in the negative direction. These results show that mirror self-recognition is a highly stable trait in many chimpanzees, but may be subject to decline with age. Connections with human research are briefly discussed.

  10. The interplay between perceptual organization and object recognition: Temporal dynamics and neuropsychology

    OpenAIRE

    Torfs, Katrien

    2012-01-01

    The ease and efficiency with which we perceive objects in daily life masks the complexity of the processes involved. The main goal of my doctoral research was to enhance our understanding of the complex interplay between perceptual organization and object recognition. To this end, we investigated the dynamic interplay between different component processes of object recognition, and their temporal dynamics. In the first part of this thesis, I present three behavioral studies focusing on the ro...

  11. Statistical Pattern Recognition

    CERN Document Server

    Webb, Andrew R

    2011-01-01

    Statistical pattern recognition relates to the use of statistical techniques for analysing data measurements in order to extract information and make justified decisions.  It is a very active area of study and research, which has seen many advances in recent years. Applications such as data mining, web searching, multimedia data retrieval, face recognition, and cursive handwriting recognition, all require robust and efficient pattern recognition techniques. This third edition provides an introduction to statistical pattern theory and techniques, with material drawn from a wide range of fields,

  12. Hybrid generative-discriminative approach to age-invariant face recognition

    Science.gov (United States)

    Sajid, Muhammad; Shafique, Tamoor

    2018-03-01

    Age-invariant face recognition is still a challenging research problem due to the complex aging process involving types of facial tissues, skin, fat, muscles, and bones. Most of the related studies that have addressed the aging problem are focused on generative representation (aging simulation) or discriminative representation (feature-based approaches). Designing an appropriate hybrid approach taking into account both the generative and discriminative representations for age-invariant face recognition remains an open problem. We perform a hybrid matching to achieve robustness to aging variations. This approach automatically segments the eyes, nose-bridge, and mouth regions, which are relatively less sensitive to aging variations compared with the rest of the facial regions that are age-sensitive. The aging variations of age-sensitive facial parts are compensated using a demographic-aware generative model based on a bridged denoising autoencoder. The age-insensitive facial parts are represented by pixel average vector-based local binary patterns. Deep convolutional neural networks are used to extract relative features of age-sensitive and age-insensitive facial parts. Finally, the feature vectors of age-sensitive and age-insensitive facial parts are fused to achieve the recognition results. Extensive experimental results on morphological face database II (MORPH II), face and gesture recognition network (FG-NET), and Verification Subset of cross-age celebrity dataset (CACD-VS) demonstrate the effectiveness of the proposed method for age-invariant face recognition well.

  13. Computational modeling of chemical reactions and interstitial growth and remodeling involving charged solutes and solid-bound molecules.

    Science.gov (United States)

    Ateshian, Gerard A; Nims, Robert J; Maas, Steve; Weiss, Jeffrey A

    2014-10-01

    Mechanobiological processes are rooted in mechanics and chemistry, and such processes may be modeled in a framework that couples their governing equations starting from fundamental principles. In many biological applications, the reactants and products of chemical reactions may be electrically charged, and these charge effects may produce driving forces and constraints that significantly influence outcomes. In this study, a novel formulation and computational implementation are presented for modeling chemical reactions in biological tissues that involve charged solutes and solid-bound molecules within a deformable porous hydrated solid matrix, coupling mechanics with chemistry while accounting for electric charges. The deposition or removal of solid-bound molecules contributes to the growth and remodeling of the solid matrix; in particular, volumetric growth may be driven by Donnan osmotic swelling, resulting from charged molecular species fixed to the solid matrix. This formulation incorporates the state of strain as a state variable in the production rate of chemical reactions, explicitly tying chemistry with mechanics for the purpose of modeling mechanobiology. To achieve these objectives, this treatment identifies the specific theoretical and computational challenges faced in modeling complex systems of interacting neutral and charged constituents while accommodating any number of simultaneous reactions where reactants and products may be modeled explicitly or implicitly. Several finite element verification problems are shown to agree with closed-form analytical solutions. An illustrative tissue engineering analysis demonstrates tissue growth and swelling resulting from the deposition of chondroitin sulfate, a charged solid-bound molecular species. This implementation is released in the open-source program FEBio ( www.febio.org ). The availability of this framework may be particularly beneficial to optimizing tissue engineering culture systems by examining the

  14. Sensor-based Human Activity Recognition in a Multi-user Scenario

    DEFF Research Database (Denmark)

    Wang, Liang; Gu, Tao; Tao, Xianping

    2009-01-01

    Existing work on sensor-based activity recognition focuses mainly on single-user activities. However, in real life, activities are often performed by multiple users involving interactions between them. In this paper, we propose Coupled Hidden Markov Models (CHMMs) to recognize multi-user activiti...

  15. Spectroscopic probes of vibrationally excited molecules at chemically significant energies

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, T.R. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project involves the application of multiple-resonance spectroscopic techniques for investigating energy transfer and dissociation dynamics of highly vibrationally excited molecules. Two major goals of this work are: (1) to provide information on potential energy surfaces of combustion related molecules at chemically significant energies, and (2) to test theoretical modes of unimolecular dissociation rates critically via quantum-state resolved measurements.

  16. Not all attention orienting is created equal: recognition memory is enhanced when attention orienting involves distractor suppression.

    Science.gov (United States)

    Markant, Julie; Worden, Michael S; Amso, Dima

    2015-04-01

    Learning through visual exploration often requires orienting of attention to meaningful information in a cluttered world. Previous work has shown that attention modulates visual cortex activity, with enhanced activity for attended targets and suppressed activity for competing inputs, thus enhancing the visual experience. Here we examined the idea that learning may be engaged differentially with variations in attention orienting mechanisms that drive eye movements during visual search and exploration. We hypothesized that attention orienting mechanisms that engaged suppression of a previously attended location would boost memory encoding of the currently attended target objects to a greater extent than those that involve target enhancement alone. To test this hypothesis we capitalized on the classic spatial cueing task and the inhibition of return (IOR) mechanism (Posner, 1980; Posner, Rafal, & Choate, 1985) to demonstrate that object images encoded in the context of concurrent suppression at a previously attended location were encoded more effectively and remembered better than those encoded without concurrent suppression. Furthermore, fMRI analyses revealed that this memory benefit was driven by attention modulation of visual cortex activity, as increased suppression of the previously attended location in visual cortex during target object encoding predicted better subsequent recognition memory performance. These results suggest that not all attention orienting impacts learning and memory equally. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Discrete Neural Correlates for the Recognition of Negative Emotions: Insights from Frontotemporal Dementia

    Science.gov (United States)

    Kumfor, Fiona; Irish, Muireann; Hodges, John R.; Piguet, Olivier

    2013-01-01

    Patients with frontotemporal dementia have pervasive changes in emotion recognition and social cognition, yet the neural changes underlying these emotion processing deficits remain unclear. The multimodal system model of emotion proposes that basic emotions are dependent on distinct brain regions, which undergo significant pathological changes in frontotemporal dementia. As such, this syndrome may provide important insight into the impact of neural network degeneration upon the innate ability to recognise emotions. This study used voxel-based morphometry to identify discrete neural correlates involved in the recognition of basic emotions (anger, disgust, fear, sadness, surprise and happiness) in frontotemporal dementia. Forty frontotemporal dementia patients (18 behavioural-variant, 11 semantic dementia, 11 progressive nonfluent aphasia) and 27 healthy controls were tested on two facial emotion recognition tasks: The Ekman 60 and Ekman Caricatures. Although each frontotemporal dementia group showed impaired recognition of negative emotions, distinct associations between emotion-specific task performance and changes in grey matter intensity emerged. Fear recognition was associated with the right amygdala; disgust recognition with the left insula; anger recognition with the left middle and superior temporal gyrus; and sadness recognition with the left subcallosal cingulate, indicating that discrete neural substrates are necessary for emotion recognition in frontotemporal dementia. The erosion of emotion-specific neural networks in neurodegenerative disorders may produce distinct profiles of performance that are relevant to understanding the neurobiological basis of emotion processing. PMID:23805313

  18. Chronic minocycline treatment improves social recognition memory in adult male Fmr1 knockout mice.

    Science.gov (United States)

    Yau, Suk Yu; Chiu, Christine; Vetrici, Mariana; Christie, Brian R

    2016-10-01

    Fragile X syndrome (FXS) is caused by a mutation in the Fmr1 gene that leads to silencing of the gene and a loss of its gene product, Fragile X mental retardation protein (FMRP). Some of the key behavioral phenotypes for FXS include abnormal social anxiety and sociability. Here we show that Fmr1 knock-out (KO) mice exhibit impaired social recognition when presented with a novel mouse, and they display normal social interactions in other sociability tests. Administering minocycline to Fmr1 KO mice throughout critical stages of neural development improved social recognition memory in the novel mouse recognition task. To determine if synaptic changes in the prefrontal cortex (PFC) could have played a role in this improvement, we examined PSD-95, a member of the membrane-associated guanylate kinase family, and signaling molecules (ERK1/2, and Akt) linked to synaptic plasticity in the PFC. Our analyses indicated that while minocycline treatment can enhance behavioral performance, it does not enhance expression of PSD-95, ERK1/2 or Akt in the PFC. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Cluster ions and van der Waals molecules

    CERN Document Server

    Smirnov, Boris M

    1992-01-01

    This review discusses current ideas in the physics and chemistry of cluster ions and Van der Waals molecules as well as presenting numerical data on their parameters and the processes involving them. It is also a detailed reference on basic data relating to many species.

  20. Heterobifunctional crosslinkers for tethering single ligand molecules to scanning probes

    International Nuclear Information System (INIS)

    Riener, Christian K.; Kienberger, Ferry; Hahn, Christoph D.; Buchinger, Gerhard M.; Egwim, Innocent O.C.; Haselgruebler, Thomas; Ebner, Andreas; Romanin, Christoph; Klampfl, Christian; Lackner, Bernd; Prinz, Heino; Blaas, Dieter; Hinterdorfer, Peter; Gruber, Hermann J.

    2003-01-01

    Single molecule recognition force microscopy (SMRFM) is a versatile atomic force microscopy (AFM) method to probe specific interactions of cognitive molecules on the single molecule level. It allows insights to be gained into interaction potentials and kinetic barriers and is capable of mapping interaction sites with nm positional accuracy. These applications require a ligand to be attached to the AFM tip, preferably by a distensible poly(ethylene glycol) (PEG) chain between the measuring tip and the ligand molecule. The PEG chain greatly facilitates specific binding of the ligand to immobile receptor sites on the sample surface. The present study contributes to tip-PEG-ligand tethering in three ways: (i) a convenient synthetic route was found to prepare NH 2 -PEG-COOH which is the key intermediate for long heterobifunctional crosslinkers; (ii) a variety of heterobifunctional PEG derivatives for tip-PEG-ligand linking were prepared from NH 2 -PEG-COOH; (iii) in particular, a new PEG crosslinker with one thiol-reactive end and one terminal nitrilotriacetic acid (NTA) group was synthesized and successfully used to tether His 6 -tagged protein molecules to AFM tips via noncovalent NTA-Ni 2+ -His 6 bridges. The new crosslinker was applied to link a recombinant His 6 -tagged fragment of the very-low density lipoprotein receptor to the AFM tip whereupon specific docking to the capsid of human rhinovirus particles was observed by force microscopy. In a parallel study, the specific interaction of the small GTPase Ran with the nuclear import receptor importin β1 was studied in detail by SMRFM, using the new crosslinker to link His 6 -tagged Ran to the measuring tip [Nat. Struct. Biol. (2003), 10, 553-557

  1. Rotation-invariant neural pattern recognition system with application to coin recognition.

    Science.gov (United States)

    Fukumi, M; Omatu, S; Takeda, F; Kosaka, T

    1992-01-01

    In pattern recognition, it is often necessary to deal with problems to classify a transformed pattern. A neural pattern recognition system which is insensitive to rotation of input pattern by various degrees is proposed. The system consists of a fixed invariance network with many slabs and a trainable multilayered network. The system was used in a rotation-invariant coin recognition problem to distinguish between a 500 yen coin and a 500 won coin. The results show that the approach works well for variable rotation pattern recognition.

  2. Sensitive and Specific Guest Recognition through Pyridinium-Modification in Spindle-Like Coordination Containers.

    Science.gov (United States)

    Bhuvaneswari, Nagarajan; Dai, Feng-Rong; Chen, Zhong-Ning

    2018-05-02

    An elaborately designed pyridinium-functionalized octanuclear zinc(II) coordination container 1-Zn was prepared through the self-assembly of Zn 2+ , p-tert-butylsulfonylcalix[4]arene, and pyridinium-functionalized angular flexible dicarboxylate linker (H 2 BrL1). The structure was determined by a single-crystal X-ray diffractometer. 1-Zn displays highly sensitive and specific recognition to 2-picolylamine as revealed by drastic blueshifts of the absorption and emission spectra, ascribed to the decrease of intramolecular charge transfer (ICT) character of the container and the occurrence of intermolecular charge transfer between the host and guest molecules. The intramolecular charge transfer plays a key role in the modulation of the electronic properties and is tunable through endo-encapsulation of specific guest molecules. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Laser Controlled Synthesis of Noble Metal Nanoparticle Arrays for Low Concentration Molecule Recognition

    Directory of Open Access Journals (Sweden)

    Enza Fazio

    2014-12-01

    Full Text Available Nanostructured gold and silver thin films were grown by pulsed laser deposition.Performing the process in an ambient gas (Ar leads to the nucleation and growth ofnanoparticles in the ablation plasma and their self-organization on the substrate. Thedependence of surface nanostructuring of the films on the deposition parameters is discussedconsidering in particular the number of laser pulses and the ambient gas nature and pressure.The performance of the deposited thin films as substrates for surface-enhanced Ramanspectroscopy (SERS was tested against the detection of molecules at a low concentration.Taking Raman maps on micrometer-sized areas, the spatial homogeneity of the substrateswith respect to the SERS signal was tested.

  4. Improved Dye Stability in Single-Molecule Fluorescence Experiments

    Science.gov (United States)

    EcheverrÍa Aitken, Colin; Marshall, R. Andrew; Pugi, Joseph D.

    Complex biological systems challenge existing single-molecule methods. In particular, dye stability limits observation time in singlemolecule fluorescence applications. Current approaches to improving dye performance involve the addition of enzymatic oxygen scavenging systems and small molecule additives. We present an enzymatic oxygen scavenging system that improves dye stability in single-molecule experiments. Compared to the currently-employed glucose-oxidase/catalase system, the protocatechuate-3,4-dioxygenase system achieves lower dissolved oxygen concentration and stabilizes single Cy3, Cy5, and Alexa488 fluorophores. Moreover, this system possesses none of the limitations associated with the glucose oxidase/catalase system. We also tested the effects of small molecule additives in this system. Biological reducing agents significantly destabilize the Cy5 fluorophore as a function of reducing potential. In contrast, anti-oxidants stabilize the Cy3 and Alexa488 fluorophores. We recommend use of the protocatechuate-3,4,-dioxygenase system with antioxidant additives, and in the absence of biological reducing agents. This system should have wide application to single-molecule fluorescence experiments.

  5. Electrical transport through a metal-molecule-metal junction; Transport electrique a travers une jonction metal-molecule-metal

    Energy Technology Data Exchange (ETDEWEB)

    Kergueris, Ch

    1998-12-17

    We investigate the electrical transport through a very few molecules connected to metallic electrodes at room temperature. First, the state of the art in molecular electronics is outlined. We present the most convincing molecular devices reported so far in the literature and the theoretical tools available to analyze the electron transport mechanism through a molecular junction. Second, we describe the use of mechanically controllable break junctions to investigate the electron transport properties through a metal-molecule-metal junction. Two kindsof molecules were adsorbed on the two facing gold electrodes, dodecane-thiol (DT) and bis-thiol-ter-thiophene ({alpha},{omega} T3), that are basically expected to behave as an insulator and as a molecular wire, respectively. In the latter case, we study the chemical reactivity of the molecule and show that {alpha},{omega} T3 is chemically adsorbed on gold electrodes. Current-voltage characteristics of the junction were observed at room temperature. The Gold-DT-Gold junction behaves as a simple metal-insulator-metal junction. On the other hand, the electron transport through a Gold-{alpha},{omega} T3-Gold junction explicitly involves the electronic structure of the molecule which gives rise to step-like features in the current-voltage characteristics. The measured zero bias conductance is interpreted using the scattering theory. At high bias, we discuss two different models: a coherent model where the electron has no time to be completely re-localized in the molecule and a sequential model where the electron is localized in the molecule during the transfer. Finally, we show that the mechanical action of decreasing the inter-electrodes spacing can be used to induce a strong modification of the current-voltage characteristics. (author)

  6. Speech recognition systems on the Cell Broadband Engine

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Y; Jones, H; Vaidya, S; Perrone, M; Tydlitat, B; Nanda, A

    2007-04-20

    In this paper we describe our design, implementation, and first results of a prototype connected-phoneme-based speech recognition system on the Cell Broadband Engine{trademark} (Cell/B.E.). Automatic speech recognition decodes speech samples into plain text (other representations are possible) and must process samples at real-time rates. Fortunately, the computational tasks involved in this pipeline are highly data-parallel and can receive significant hardware acceleration from vector-streaming architectures such as the Cell/B.E. Identifying and exploiting these parallelism opportunities is challenging, but also critical to improving system performance. We observed, from our initial performance timings, that a single Cell/B.E. processor can recognize speech from thousands of simultaneous voice channels in real time--a channel density that is orders-of-magnitude greater than the capacity of existing software speech recognizers based on CPUs (central processing units). This result emphasizes the potential for Cell/B.E.-based speech recognition and will likely lead to the future development of production speech systems using Cell/B.E. clusters.

  7. Corticosterone and propranolol's role on taste recognition memory.

    Science.gov (United States)

    Ruetti, E; Justel, N; Mustaca, A; Boccia, M

    2014-12-01

    Taste recognition is a robust procedure to study learning and memory processes, as well as the different stages involved in them, i.e. encoding, storage and recall. Considerable evidence indicates that adrenal hormones and the noradrenergic system play an important role in aversive and appetitive memory formation in rats and humans. The present experiments were designed to characterize the effects of immediate post training corticosterone (Experiment 1) and propranolol administration (Experiment 2 and 3) on taste recognition memory. Administration of a high dose of corticosterone (5mg/kg, sc) impairs consolidation of taste memory, but the low and moderate doses (1 and 3mg/kg, sc) didn't affect it. On the other hand, immediate post-training administration of propranolol (1 and 2mg/kg, ip) impaired taste recognition memory. These effects were time-dependent since no effects were seen when drug administration was delayed 3h after training. These findings support the importance of stress hormones and noradrenergic system on the modulation of taste memory consolidation. Copyright © 2014. Published by Elsevier Inc.

  8. Perceptual and affective mechanisms in facial expression recognition: An integrative review.

    Science.gov (United States)

    Calvo, Manuel G; Nummenmaa, Lauri

    2016-09-01

    Facial expressions of emotion involve a physical component of morphological changes in a face and an affective component conveying information about the expresser's internal feelings. It remains unresolved how much recognition and discrimination of expressions rely on the perception of morphological patterns or the processing of affective content. This review of research on the role of visual and emotional factors in expression recognition reached three major conclusions. First, behavioral, neurophysiological, and computational measures indicate that basic expressions are reliably recognized and discriminated from one another, albeit the effect may be inflated by the use of prototypical expression stimuli and forced-choice responses. Second, affective content along the dimensions of valence and arousal is extracted early from facial expressions, although this coarse affective representation contributes minimally to categorical recognition of specific expressions. Third, the physical configuration and visual saliency of facial features contribute significantly to expression recognition, with "emotionless" computational models being able to reproduce some of the basic phenomena demonstrated in human observers. We conclude that facial expression recognition, as it has been investigated in conventional laboratory tasks, depends to a greater extent on perceptual than affective information and mechanisms.

  9. Molecular cloning and functional characterization of peptidoglycan recognition protein OmPGRP-L2 from the rainbow trout, Oncorhynchus mykiss.

    Science.gov (United States)

    Jang, Ju Hye; Kim, Hyun; Cho, Ju Hyun

    2017-10-01

    Peptidoglycan recognition proteins (PGRPs), a group of pattern recognition receptors (PRRs), are innate immune molecules that are structurally conserved through evolution in both invertebrate and vertebrate animals. In teleost fish, several PGRPs have been characterized recently. They have both amidase activity and bactericidal activity and are involved in indirectly killing bacteria and regulating multiple signaling pathways. However, the knowledge of functional similarity and divergence between PGRP paralogs for their role as an immune modulator in teleost fish is still limited. In this study, we identified a novel PGRP paralog, termed OmPGRP-L2 from the rainbow trout (Oncorhynchus mykiss). OmPGRP-L2 contains the conserved PGRP domain and the four Zn 2+ -binding amino acid residues required for amidase activity. Quantitative RT-PCR analysis indicated that OmPGRP-L2 is highly expressed in liver. Overexpression of OmPGRP-L2 in a rainbow trout hepatocyte cell line RTH-149 challenged with Edwardsiella tarda resulted in down-regulation of IL-1β and TNF-α expression. When overexpressed in RTH-149 cells, OmPGRP-L2 inhibited NF-κB activity with or without bacterial stimulation. Collectively, these findings suggest that OmPGRP-L2 has an immunomodulatory function, via NF-κB inhibition in liver. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Magnetic field modification of ultracold molecule-molecule collisions

    International Nuclear Information System (INIS)

    Tscherbul, T V; Suleimanov, Yu V; Aquilanti, V; Krems, R V

    2009-01-01

    We present an accurate quantum mechanical study of molecule-molecule collisions in the presence of a magnetic field. The work focuses on the analysis of elastic scattering and spin relaxation in collisions of O 2 ( 3 Σ g - ) molecules at cold (∼0.1 K) and ultracold (∼10 -6 K) temperatures. Our calculations show that magnetic spin relaxation in molecule-molecule collisions is extremely efficient except at magnetic fields below 1 mT. The rate constant for spin relaxation at T=0.1 K and a magnetic field of 0.1 T is found to be as large as 6.1x10 -11 cm -3 s -1 . The magnetic field dependence of elastic and inelastic scattering cross sections at ultracold temperatures is dominated by a manifold of Feshbach resonances with the density of ∼100 resonances per Tesla for collisions of molecules in the absolute ground state. This suggests that the scattering length of ultracold molecules in the absolute ground state can be effectively tuned in a very wide range of magnetic fields. Our calculations demonstrate that the number and properties of the magnetic Feshbach resonances are dramatically different for molecules in the absolute ground and excited spin states. The density of Feshbach resonances for molecule-molecule scattering in the low-field-seeking Zeeman state is reduced by a factor of 10.

  11. Structural Basis for Degenerate Recognition of Natural HIV Peptide Variants by Cytotoxic Lymphocytes

    International Nuclear Information System (INIS)

    Martinez-Hackert, E.; Anikeeva, N.; Kalams, S.; Walker, B.; Hendrickson, W.; Sykulev, Y.

    2006-01-01

    It is well established that even small changes in amino acid side chains of antigenic peptide bound to MHC protein may completely abrogate recognition of the peptide-MHC (pMHC) complex by the T-cell receptor (TCR). Often, however, several non-conservative substitutions in the peptide antigen are accommodated and do not impair its recognition by TCR. For example, a preponderance of natural sequence variants of the HIV p17 Gag-derived peptide SLYNTVATL (SL9) are recognized by cytotoxic T lymphocytes (CTL), which implies that interactions with SL9 variants are degenerate both with respect to the class I MHC molecule and with respect to TCR. Here we study the molecular basis for this degenerate recognition of SL9 variants. We show that several SL9 variants bind comparably well to soluble HLA-A2 and to a particular soluble TCR and that these variants are active in the cognate cytotoxicity assay. Natural SL9 variation is restricted by its context in the HIV p17 matrix protein, and we have used synthetic variants to explore the wider spectrum of recognition. High-resolution crystal structures of seven selected SL9 variants bound to HLA-A2 all have remarkably similar peptide conformations and side-chain dispositions outside sites of substitution. This preservation of the peptide conformation despite epitope variations suggests a mechanism for the observed degeneracy in pMHC recognition by TCR, and may contribute to the persistence of SL9-mediated immune responses in chronically infected individuals

  12. Stages of processing in associative recognition: evidence from behavior, EEG, and classification.

    Science.gov (United States)

    Borst, Jelmer P; Schneider, Darryl W; Walsh, Matthew M; Anderson, John R

    2013-12-01

    In this study, we investigated the stages of information processing in associative recognition. We recorded EEG data while participants performed an associative recognition task that involved manipulations of word length, associative fan, and probe type, which were hypothesized to affect the perceptual encoding, retrieval, and decision stages of the recognition task, respectively. Analyses of the behavioral and EEG data, supplemented with classification of the EEG data using machine-learning techniques, provided evidence that generally supported the sequence of stages assumed by a computational model developed in the Adaptive Control of Thought-Rational cognitive architecture. However, the results suggested a more complex relationship between memory retrieval and decision-making than assumed by the model. Implications of the results for modeling associative recognition are discussed. The study illustrates how a classifier approach, in combination with focused manipulations, can be used to investigate the timing of processing stages.

  13. Chemical wiring and soldering toward all-molecule electronic circuitry.

    Science.gov (United States)

    Okawa, Yuji; Mandal, Swapan K; Hu, Chunping; Tateyama, Yoshitaka; Goedecker, Stefan; Tsukamoto, Shigeru; Hasegawa, Tsuyoshi; Gimzewski, James K; Aono, Masakazu

    2011-06-01

    Key to single-molecule electronics is connecting functional molecules to each other using conductive nanowires. This involves two issues: how to create conductive nanowires at designated positions, and how to ensure chemical bonding between the nanowires and functional molecules. Here, we present a novel method that solves both issues. Relevant functional molecules are placed on a self-assembled monolayer of diacetylene compound. A probe tip of a scanning tunneling microscope is then positioned on the molecular row of the diacetylene compound to which the functional molecule is adsorbed, and a conductive polydiacetylene nanowire is fabricated by initiating chain polymerization by stimulation with the tip. Since the front edge of chain polymerization necessarily has a reactive chemical species, the created polymer nanowire forms chemical bonding with an encountered molecular element. We name this spontaneous reaction "chemical soldering". First-principles theoretical calculations are used to investigate the structures and electronic properties of the connection. We demonstrate that two conductive polymer nanowires are connected to a single phthalocyanine molecule. A resonant tunneling diode formed by this method is discussed. © 2011 American Chemical Society

  14. Improving entrepreneurial opportunity recognition through web content analytics

    Science.gov (United States)

    Bakar, Muhamad Shahbani Abu; Azmi, Azwiyati

    2017-10-01

    The ability to recognize and develop an opportunity into a venture defines an entrepreneur. Research in opportunity recognition has been robust and focuses more on explaining the processes involved in opportunity recognition. Factors such as prior knowledge, cognitive and creative capabilities are shown to affect opportunity recognition in entrepreneurs. Prior knowledge in areas such as customer problems, ways to serve the market, and technology has been shows in various studies to be a factor that facilitates entrepreneurs to identify and recognize opportunities. Findings from research also shows that experienced entrepreneurs search and scan for information to discover opportunities. Searching and scanning for information has also been shown to help novice entrepreneurs who lack prior knowledge to narrow this gap and enable them to better identify and recognize opportunities. There is less focus in research on finding empirically proven techniques and methods to develop and enhance opportunity recognition in student entrepreneurs. This is important as the country pushes for more graduate entrepreneurs that can drive the economy. This paper aims to discuss Opportunity Recognition Support System (ORSS), an information support system to help especially student entrepreneurs in identifying and recognizing business opportunities. The ORSS aims to provide the necessary knowledge to student entrepreneurs to be able to better identify and recognize opportunities. Applying design research, theories in opportunity recognition are applied to identify the requirements for the support system and the requirements in turn dictate the design of the support system. The paper proposes the use of web content mining and analytics as two core components and techniques for the support system. Web content mining can mine the vast knowledge repositories available on the internet and analytics can provide entrepreneurs with further insights into the information needed to recognize

  15. Recognition of Demobilized Youth from the Armed Groups in Colombia: Transitions and Challenges for School Practices

    OpenAIRE

    Bejarano-Sanabria, Henry Camilo; Corporación de educación tecnológica Colsubsidio-Airbus Group, CET; Delgado-Salazar, Ricardo Mauricio; Pontificia Universidad Javeriana

    2017-01-01

    This article examines how the models of social recognition contribute to the school practices of demobilized young people from the organizations involved in the armed conflict in Colombia, who decide to return to the educational system. Results of this reflection are presented in four sections. The first section deals with the structure of social recognition through three models or stages of intersubjective recognition according to Georg Wilhelm Friedrich Hegel, Axel Honneth and Paul Ricoeur....

  16. The formation of carbon chain molecules in IRC + 10216

    International Nuclear Information System (INIS)

    Howe, D.A.; Millar, T.J.

    1990-01-01

    This paper considers the formation of carbon-chain molecules, including C 2n H, C n S, HC 2n+1 N (n = 1-3) and SiC n (n = 1-4), in the outflowing envelope of the late-type carbon star IRC + 10216. The results suggest that the organo-sulphur species C 2 S and C 3 S can be formed in ion-molecule reactions involving acetylene ions and parent CS and SiS molecules. In addition to ion-molecule processes, neutral-neutral reactions can play a significant role in the formation of hydrocarbons and cyanopolyynes with up to six heavy atoms and in the formation of SiC 4 , and suggest that SiC 3 might be observable. However, the short time-scales available in the outflow are such that the observed abundances of the cyanopolyynes larger than HC 5 N cannot be reproduced using the parent molecules and abundances adopted here. (author)

  17. Opportunity recognition and international new venture creation in University spin-offs

    DEFF Research Database (Denmark)

    Hannibal, Martin; Evers, Natasha; Servais, Per

    2016-01-01

    Extant research suggests that the founder’s activities and interactions are considered pivotal in driving the opportunity recognition process leading to international new venture emergence. This paper aims to explore the opportunity recognition process and international new venture emergence...... in the context of university high-technology spin-offs that are internationally market driven from inception. University spin-offs (USOs) are defined as ‘new firms created to exploit commercially some knowledge, technology or research results developed within a university’ (Pirnay et al., Small Bus Econ 21...... that the inventor-founders are typically engaged in opportunity recognition processes that are characterized as creative, driven by scientific innovations. It is indicated that the process of USO emergence and continuous development involves activities and interactions similar to typical international new ventures...

  18. Attention, biological motion, and action recognition.

    Science.gov (United States)

    Thompson, James; Parasuraman, Raja

    2012-01-02

    Interacting with others in the environment requires that we perceive and recognize their movements and actions. Neuroimaging and neuropsychological studies have indicated that a number of brain regions, particularly the superior temporal sulcus, are involved in a number of processes essential for action recognition, including the processing of biological motion and processing the intentions of actions. We review the behavioral and neuroimaging evidence suggesting that while some aspects of action recognition might be rapid and effective, they are not necessarily automatic. Attention is particularly important when visual information about actions is degraded or ambiguous, or if competing information is present. We present evidence indicating that neural responses associated with the processing of biological motion are strongly modulated by attention. In addition, behavioral and neuroimaging evidence shows that drawing inferences from the actions of others is attentionally demanding. The role of attention in action observation has implications for everyday social interactions and workplace applications that depend on observing, understanding and interpreting actions. Published by Elsevier Inc.

  19. Ethanol and Caffeine effects on social interaction and recognition in mice: Involvement of adenosine A2A and A1 receptors

    Directory of Open Access Journals (Sweden)

    Laura López-Cruz

    2016-11-01

    Full Text Available Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A1/A2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A1 and A2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg increasing social contact and higher doses (1.0-1.5 g/kg reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg, and even blocked social preference at higher doses (30.0-60.0 mg/kg. The A1 antagonist CPT (3-9 mg/kg did not modify social contact or preference on its own, and the A2A antagonist MSX-3 (1.5-6 mg/kg increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg. Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the formation of social

  20. Concentration-related response potentiometric titrations to study the interaction of small molecules with large biomolecules.

    Science.gov (United States)

    Hamidi-Asl, Ezat; Daems, Devin; De Wael, Karolien; Van Camp, Guy; Nagels, Luc J

    2014-12-16

    In the present paper, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small-molecule interactions is reported. This approach is fast, sensitive, reproducible, and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small-molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed into a concentration-related signal over the entire concentration interval, also at low concentrations, where the millivolt (y-axis) versus log canalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anticocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis(4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using surface plasmon resonance. The potentiometric titration approach called "concentration-related response potentiometry" is used to study molecular interaction for seven macromolecular target molecules and four small-molecule ligands.

  1. Cellular endocytic compartment localization of expressed canine CD1 molecules

    DEFF Research Database (Denmark)

    Schjærff, Mette; Keller, Stefan M.; Affolter, Verena K.

    2016-01-01

    CD1 molecules are glycoproteins present primarily on dendritic cells (DCs), which recognize and presenta variety of foreign- and self-lipid antigens to T-cells. Humans have five different CD1 isoforms that sur-vey distinct cellular compartments allowing for recognition of a large repertoire...... onlya diminished GFP expression. In conclusion, canine CD1 transfectants show distinct localization patternsthat are similar to human CD1 proteins with the exception of the canine CD1d isoform, which most likelyis non-functional. These findings imply that canine CD1 localization overall resembles human...... CD1 traf-ficking patterns. This knowledge is important for the understanding of lipid antigen-receptor immunityin the dog....

  2. Detecting high-density ultracold molecules using atom–molecule collision

    International Nuclear Information System (INIS)

    Chen, Jun-Ren; Kao, Cheng-Yang; Chen, Hung-Bin; Liu, Yi-Wei

    2013-01-01

    Utilizing single-photon photoassociation, we have achieved ultracold rubidium molecules with a high number density that provides a new efficient approach toward molecular quantum degeneracy. A new detection mechanism for ultracold molecules utilizing inelastic atom–molecule collision is demonstrated. The resonant coupling effect on the formation of the X 1 Σ + g ground state 85 Rb 2 allows for a sufficient number of more deeply bound ultracold molecules, which induced an additional trap loss and heating of the co-existing atoms owing to the inelastic atom–molecule collision. Therefore, after the photoassociation process, the ultracold molecules can be investigated using the absorption image of the ultracold rubidium atoms mixed with the molecules in a crossed optical dipole trap. The existence of the ultracold molecules was then verified, and the amount of accumulated molecules was measured. This method detects the final produced ultracold molecules, and hence is distinct from the conventional trap loss experiment, which is used to study the association resonance. It is composed of measurements of the time evolution of an atomic cloud and a decay model, by which the number density of the ultracold 85 Rb 2 molecules in the optical trap was estimated to be >5.2 × 10 11 cm −3 . (paper)

  3. Dysfunctional role of parietal lobe during self-face recognition in schizophrenia.

    Science.gov (United States)

    Yun, Je-Yeon; Hur, Ji-Won; Jung, Wi Hoon; Jang, Joon Hwan; Youn, Tak; Kang, Do-Hyung; Park, Sohee; Kwon, Jun Soo

    2014-01-01

    Anomalous sense of self is central to schizophrenia yet difficult to demonstrate empirically. The present study examined the effective neural network connectivity underlying self-face recognition in patients with schizophrenia (SZ) using [15O]H2O Positron Emission Tomography (PET) and Structural Equation Modeling. Eight SZ and eight age-matched healthy controls (CO) underwent six consecutive [15O]H2O PET scans during self-face (SF) and famous face (FF) recognition blocks, each of which was repeated three times. There were no behavioral performance differences between the SF and FF blocks in SZ. Moreover, voxel-based analyses of data from SZ revealed no significant differences in the regional cerebral blood flow (rCBF) levels between the SF and FF recognition conditions. Further effective connectivity analyses for SZ also showed a similar pattern of effective connectivity network across the SF and FF recognition. On the other hand, comparison of SF recognition effective connectivity network between SZ and CO demonstrated significantly attenuated effective connectivity strength not only between the right supramarginal gyrus and left inferior temporal gyrus, but also between the cuneus and right medial prefrontal cortex in SZ. These findings support a conceptual model that posits a causal relationship between disrupted self-other discrimination and attenuated effective connectivity among the right supramarginal gyrus, cuneus, and prefronto-temporal brain areas involved in the SF recognition network of SZ. © 2013.

  4. Chiral separation of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography with biphasic recognition

    Science.gov (United States)

    Tong, Shengqiang

    2010-01-01

    This work concentrates on a novel chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether-water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Various parameters involved in the chiral separation were investigated, namely the types of the chiral selector (CS); the concentration of each chiral selector; pH of the mobile phase; and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for each chiral selector. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both lipophilic and hydrophilic chiral selectors. PMID:20303497

  5. The neuro-immunological interface in an evolutionary perspective: the dynamic relationship between effector and recognition systems.

    Science.gov (United States)

    Ottaviani, E; Valensin, S; Franceschi, C

    1998-04-16

    The evolutionary perspective indicates that an immune-neuroendocrine effector system integrating innate immunity, stress and inflammation is present in invertebrates. This defense network, centered on the macrophage and exerting primitive and highly promiscuous recognition units, is very effective, ancestral and appears to have been conserved throughout evolution from invertebrates to higher vertebrates. It would seem that there was a "big bang" in the recognition system of lower vertebrates, and T and B cell repertoires, MHC and antibodies suddenly appeared. We argue that this phenomenon is the counterpart of the increasing complexity of the internal circuitry and recognition units in the effector system. The immediate consequences were a progressive enlargement of the pathogen repertoire and new problems regarding self/not-self discrimination. Probably not by chance, a new organ appeared, capable of purging cells able of excessive self recognition. This organ, the thymus, appears to be the result of a well known evolutionary strategy of re-using pre-existing material (neuroendocrine cells and mediators constituting the thymic microenvironment). This bricolage at an organ level is similar to the effect we have already described at the level of molecules and functions of the defense network, and has a general counterpart at genetic level. Thus, in vertebrates, the conserved immune-neuroendocrine effector system remains of fundamental importance in defense against pathogens, while its efficiency has increased through synergy with the new, clonotipical recognition repertoire.

  6. Feature selection in classification of eye movements using electrooculography for activity recognition.

    Science.gov (United States)

    Mala, S; Latha, K

    2014-01-01

    Activity recognition is needed in different requisition, for example, reconnaissance system, patient monitoring, and human-computer interfaces. Feature selection plays an important role in activity recognition, data mining, and machine learning. In selecting subset of features, an efficient evolutionary algorithm Differential Evolution (DE), a very efficient optimizer, is used for finding informative features from eye movements using electrooculography (EOG). Many researchers use EOG signals in human-computer interactions with various computational intelligence methods to analyze eye movements. The proposed system involves analysis of EOG signals using clearness based features, minimum redundancy maximum relevance features, and Differential Evolution based features. This work concentrates more on the feature selection algorithm based on DE in order to improve the classification for faultless activity recognition.

  7. Application of machine learning methods for traffic signs recognition

    Science.gov (United States)

    Filatov, D. V.; Ignatev, K. V.; Deviatkin, A. V.; Serykh, E. V.

    2018-02-01

    This paper focuses on solving a relevant and pressing safety issue on intercity roads. Two approaches were considered for solving the problem of traffic signs recognition; the approaches involved neural networks to analyze images obtained from a camera in the real-time mode. The first approach is based on a sequential image processing. At the initial stage, with the help of color filters and morphological operations (dilatation and erosion), the area containing the traffic sign is located on the image, then the selected and scaled fragment of the image is analyzed using a feedforward neural network to determine the meaning of the found traffic sign. Learning of the neural network in this approach is carried out using a backpropagation method. The second approach involves convolution neural networks at both stages, i.e. when searching and selecting the area of the image containing the traffic sign, and when determining its meaning. Learning of the neural network in the second approach is carried out using the intersection over union function and a loss function. For neural networks to learn and the proposed algorithms to be tested, a series of videos from a dash cam were used that were shot under various weather and illumination conditions. As a result, the proposed approaches for traffic signs recognition were analyzed and compared by key indicators such as recognition rate percentage and the complexity of neural networks’ learning process.

  8. Biomolecule-recognition gating membrane using biomolecular cross-linking and polymer phase transition.

    Science.gov (United States)

    Kuroki, Hidenori; Ito, Taichi; Ohashi, Hidenori; Tamaki, Takanori; Yamaguchi, Takeo

    2011-12-15

    We present for the first time a biomolecule-recognition gating system that responds to small signals of biomolecules by the cooperation of biorecognition cross-linking and polymer phase transition in nanosized pores. The biomolecule-recognition gating membrane immobilizes the stimuli-responsive polymer, including the biomolecule-recognition receptor, onto the pore surface of a porous membrane. The pore state (open/closed) of this gating membrane depends on the formation of specific biorecognition cross-linking in the pores: a specific biomolecule having multibinding sites can be recognized by several receptors and acts as the cross-linker of the grafted polymer, whereas a nonspecific molecule cannot. The pore state can be distinguished by a volume phase transition of the grafted polymer. In the present study, the principle of the proposed system is demonstrated using poly(N-isopropylacrylamide) as the stimuli-responsive polymer and avidin-biotin as a multibindable biomolecule-specific receptor. As a result of the selective response to the specific biomolecule, a clear permeability change of an order of magnitude was achieved. The principle is versatile and can be applied to many combinations of multibindable analyte-specific receptors, including antibody-antigen and lectin-sugar analogues. The new gating system can find wide application in the bioanalytical field and aid the design of novel biodevices.

  9. SchNet - A deep learning architecture for molecules and materials

    Science.gov (United States)

    Schütt, K. T.; Sauceda, H. E.; Kindermans, P.-J.; Tkatchenko, A.; Müller, K.-R.

    2018-06-01

    Deep learning has led to a paradigm shift in artificial intelligence, including web, text, and image search, speech recognition, as well as bioinformatics, with growing impact in chemical physics. Machine learning, in general, and deep learning, in particular, are ideally suitable for representing quantum-mechanical interactions, enabling us to model nonlinear potential-energy surfaces or enhancing the exploration of chemical compound space. Here we present the deep learning architecture SchNet that is specifically designed to model atomistic systems by making use of continuous-filter convolutional layers. We demonstrate the capabilities of SchNet by accurately predicting a range of properties across chemical space for molecules and materials, where our model learns chemically plausible embeddings of atom types across the periodic table. Finally, we employ SchNet to predict potential-energy surfaces and energy-conserving force fields for molecular dynamics simulations of small molecules and perform an exemplary study on the quantum-mechanical properties of C20-fullerene that would have been infeasible with regular ab initio molecular dynamics.

  10. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

    Science.gov (United States)

    Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

    2009-09-09

    repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

  11. The adaptor molecule signaling lymphocytic activation molecule (SLAM)-associated protein (SAP) is essential in mechanisms involving the Fyn tyrosine kinase for induction and progression of collagen-induced arthritis.

    Science.gov (United States)

    Zhong, Ming-Chao; Veillette, André

    2013-11-01

    Signaling lymphocytic activation molecule-associated protein (SAP) is an Src homology 2 domain-only adaptor involved in multiple immune cell functions. It has also been linked to immunodeficiencies and autoimmune diseases, such as systemic lupus erythematosus. Here, we examined the role and mechanism of action of SAP in autoimmunity using a mouse model of autoimmune arthritis, collagen-induced arthritis (CIA). We found that SAP was essential for development of CIA in response to collagen immunization. It was also required for production of collagen-specific antibodies, which play a key role in disease pathogenesis. These effects required SAP expression in T cells, not in B cells. In mice immunized with a high dose of collagen, the activity of SAP was nearly independent of its ability to bind the protein tyrosine kinase Fyn and correlated with the capacity of SAP to promote full differentiation of follicular T helper (TFH) cells. However, with a lower dose of collagen, the role of SAP was more dependent on Fyn binding, suggesting that additional mechanisms other than TFH cell differentiation were involved. Further studies suggested that this might be due to a role of the SAP-Fyn interaction in natural killer T cell development through the ability of SAP-Fyn to promote Vav-1 activation. We also found that removal of SAP expression during progression of CIA attenuated disease severity. However, it had no effect on disease when CIA was clinically established. Together, these results indicate that SAP plays an essential role in CIA because of Fyn-independent and Fyn-dependent effects on TFH cells and, possibly, other T cell types.

  12. Mucosal-Associated Invariant T Cells: New Insights into Antigen Recognition and Activation

    Directory of Open Access Journals (Sweden)

    Xingxing Xiao

    2017-11-01

    Full Text Available Mucosal-associated invariant T (MAIT cells, a novel subpopulation of innate-like T cells that express an invariant T cell receptor (TCRα chain and a diverse TCRβ chain, can recognize a distinct set of small molecules, vitamin B metabolites, derived from some bacteria, fungi but not viruses, in the context of an evolutionarily conserved major histocompatibility complex-related molecule 1 (MR1. This implies that MAIT cells may play unique and important roles in host immunity. Although viral antigens are not recognized by this limited TCR repertoire, MAIT cells are known to be activated in a TCR-independent mechanism during some viral infections, such as hepatitis C virus and influenza virus. In this article, we will review recent works in MAIT cell antigen recognition, activation and the role MAIT cells may play in the process of bacterial and viral infections and pathogenesis of non-infectious diseases.

  13. The ties that bind what is known to the recognition of what is new.

    Science.gov (United States)

    Nelson, D L; Zhang, N; McKinney, V M

    2001-09-01

    Recognition success varies with how information is encoded (e.g., level of processing) and with what is already known as a result of past learning (e.g., word frequency). This article presents the results of experiments showing that preexisting connections involving the associates of studied words facilitate their recognition regardless of whether the words are intentionally encoded or are incidentally encoded under semantic or nonsemantic conditions. Words are more likely to be recognized when they have either more resonant connections coming back to them from their associates or more connections among their associates. Such results occur even though attention is never drawn to these associates. Regression analyses showed that these connections affect recognition independently of frequency, so the present results add to the literature showing that prior lexical knowledge contributes to episodic recognition. In addition, equations that use free-association data to derive composite strength indices of resonance and connectivity were evaluated. Implications for theories of recognition are discussed.

  14. CEACAM3-mediated phagocytosis of human-specific bacterial pathogens involves the adaptor molecule Nck

    OpenAIRE

    Peterson, Lisa

    2010-01-01

    Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are exploited by human-specific pathogens to anchor themselves to or invade host cells. Interestingly, human granulocytes express a specific isoform, CEACAM3, that can direct efficient, opsonin-independent phagocytosis of CEACAM-binding Neisseria, Moraxella and Haemophilus species. As opsonin-independent phagocytosis of CEACAM-binding Neisseria depends on Src-family protein tyrosine kinase (PTK) phosphorylation of the CEACAM3 ...

  15. 20180410 - Finding small molecules in big data (Analytica)

    Science.gov (United States)

    Metabolomics and exposomics are amongst the youngest and most dynamic of the omics disciplines. While the molecules involved are smaller than proteomics and the other, larger “omics”, the challenges are in many ways greater. Elements are less constrained, there are no...

  16. Bihippocampal damage with emotional dysfunction: impaired auditory recognition of fear.

    Science.gov (United States)

    Ghika-Schmid, F; Ghika, J; Vuilleumier, P; Assal, G; Vuadens, P; Scherer, K; Maeder, P; Uske, A; Bogousslavsky, J

    1997-01-01

    A right-handed man developed a sudden transient, amnestic syndrome associated with bilateral hemorrhage of the hippocampi, probably due to Urbach-Wiethe disease. In the 3rd month, despite significant hippocampal structural damage on imaging, only a milder degree of retrograde and anterograde amnesia persisted on detailed neuropsychological examination. On systematic testing of recognition of facial and vocal expression of emotion, we found an impairment of the vocal perception of fear, but not that of other emotions, such as joy, sadness and anger. Such selective impairment of fear perception was not present in the recognition of facial expression of emotion. Thus emotional perception varies according to the different aspects of emotions and the different modality of presentation (faces versus voices). This is consistent with the idea that there may be multiple emotion systems. The study of emotional perception in this unique case of bilateral involvement of hippocampus suggests that this structure may play a critical role in the recognition of fear in vocal expression, possibly dissociated from that of other emotions and from that of fear in facial expression. In regard of recent data suggesting that the amygdala is playing a role in the recognition of fear in the auditory as well as in the visual modality this could suggest that the hippocampus may be part of the auditory pathway of fear recognition.

  17. The synthesis of complex molecules in interstellar clouds

    Science.gov (United States)

    Huntress, W. T., Jr.; Mitchell, G. F.

    1979-01-01

    The abundances of polyatomic molecules that may be formed by CH3(+) radiative association reactions in dense interstellar molecular clouds are reevaluated. The formation of a number of complex interstellar molecules via radiative association reactions involving ionic precursors other than CH3(+) is also investigated; these additional precursors include CH3O(+), CH3CO(+), CH5(+), HCO(+), NO(+), H2CN(+), C2H2(+), and NH3(+). The results indicate that the postulated gas-phase ion-molecule radiative association reactions could potentially explain the synthesis of most of the more complex species observed in dense molecular clouds such as Sgr B2. It is concluded, however, that in order to be conclusive, laboratory data are needed to show whether or not these reactions proceed at the required rates at low temperatures.

  18. First MARS exercise of merit recognition: what's the outcome?

    CERN Multimedia

    Staff Association

    2007-01-01

    In June, the decisions concerning the various forms of merit recognition of the staff are taken. The Staff Association commends all those involved and, in particular, the supervisors who, for this first exercise, have had to assess your performance in record time, in accordance with the new provisions in the recently revised administrative circular no. 26.

  19. Emotion recognition impairment and apathy after subthalamic nucleus stimulation in Parkinson's disease have separate neural substrates.

    Science.gov (United States)

    Drapier, D; Péron, J; Leray, E; Sauleau, P; Biseul, I; Drapier, S; Le Jeune, F; Travers, D; Bourguignon, A; Haegelen, C; Millet, B; Vérin, M

    2008-09-01

    To test the hypothesis that emotion recognition and apathy share the same functional circuit involving the subthalamic nucleus (STN). A consecutive series of 17 patients with advanced Parkinson's disease (PD) was assessed 3 months before (M-3) and 3 months (M+3) after STN deep brain stimulation (DBS). Mean (+/-S.D.) age at surgery was 56.9 (8.7) years. Mean disease duration at surgery was 11.8 (2.6) years. Apathy was measured using the Apathy Evaluation Scale (AES) at both M-3 and M3. Patients were also assessed using a computerised paradigm of facial emotion recognition [Ekman, P., & Friesen, W. V. (1976). Pictures of facial affect. Palo Alto: Consulting Psychologist Press] before and after STN DBS. Prior to this, the Benton Facial Recognition Test was used to check that the ability to perceive faces was intact. Apathy had significantly worsened at M3 (42.5+/-8.9, p=0.006) after STN-DBS, in relation to the preoperative assessment (37.2+/-5.5). There was also a significant reduction in recognition percentages for facial expressions of fear (43.1%+/-22.9 vs. 61.6%+/-21.4, p=0.022) and sadness (52.7%+/-19.1 vs. 67.6%+/-22.8, p=0.031) after STN DBS. However, the postoperative worsening of apathy and emotion recognition impairment were not correlated. Our results confirm that the STN is involved in both the apathy and emotion recognition networks. However, the absence of any correlation between apathy and emotion recognition impairment suggests that the worsening of apathy following surgery could not be explained by a lack of facial emotion recognition and that its behavioural and cognitive components should therefore also be taken into consideration.

  20. Design of polymer motifs for nucleic acid recognition and assembly stabilization

    Science.gov (United States)

    Zhou, Zhun

    This dissertation describes the synthesis and assembly of bio-functional polymers and the applications of these polymers to drug encapsulation, delivery, and multivalent biomimetic macromolecular recognition between synthetic polymer and nucleic acids. The main content is divided into three parts: (1) polyacidic domains as strongly stabilizing design elements for aqueous phase polyacrylate diblock assembly; (2) small molecule/polymer recognition triggered macromolecular assembly and drug encapsulation; (3) trizaine derivatized polymer as a novel class of "bifacial polymer nucleic acid" (bPoNA) and applications of bPoNA to nanoparticle loading of DNA/RNA, silencing delivery as well as control of aptamer function. Through the studies in part (1) and part (2), it was demonstrated that well-designed polymer motifs are not only able to enhance assemblies driven by non-specific hydrophobic effect, but are also able to direct assemblies based on specific recognitions. In part (3) of this dissertation, this concept was further extended by the design of polyacrylate polymers that are capable of discrete and robust hybridization with nucleic acids. This surprising finding demonstrated both fundamental and practical applications. Overall, these studies provided insights into the rational design elements for improving the bio-functions of synthetic polymers, and significantly expanded the scope of biological applications in which polymers synthesized via controlled radical polymerization may play a role.

  1. Vibrationally coupled electron transport through single-molecule junctions

    Energy Technology Data Exchange (ETDEWEB)

    Haertle, Rainer

    2012-04-26

    vibrational effects have a profound influence on the transport characteristics of a single-molecule contact and play therefore a fundamental role in this transport problem. Our findings demonstrate that vibrationally coupled electron transport through a molecular junction involves two types of processes: (i) transport processes, where an electron tunnels through the molecular bridge from one lead to the other, and (ii) electron-hole pair creation processes, where an electron tunnels from one of the leads onto the molecular bridge and back to the same lead again. Transport processes directly contribute to the electrical current flowing through a molecular contact and involve both excitation and deexcitation processes of the vibrational modes of the junction. Electron-hole pair creation processes do not directly contribute to the electrical current and typically involve only deexcitation processes. Nevertheless, they constitute a cooling mechanism for the vibrational modes of a single-molecule junction that is as important as cooling by transport processes. As the level of vibrational excitation determines the efficiency of electron transport processes, they have an indirect influence on the electrical current flowing through the junction. As we show, however, this influence can be substantial, in particular, if the molecule is coupled asymmetrically to the leads. Accounting for all these processes and their complex interrelationship, we analyze a number of intriguing transport phenomena, including rectification, negative differential resistance, anomalous peak broadening, mode-selective vibrational excitation and vibrationally induced decoherence. Moreover, we show that higher levels of vibrational excitation are obtained for weaker electronic-vibrational coupling. Thus, based on physical grounds, we establish a relation between the weak electronic-vibrational coupling limit and the limit of large bias voltages, where the level of vibrational excitation in a molecular junction

  2. Determination of isotopomers in pools of molecules with polyisotopic elements

    International Nuclear Information System (INIS)

    Zyakun, A.M.; Brenninkmeijer, C.A.M.

    2002-01-01

    Polyisotopic element atoms that are present in a molecule form a pool of isotopomer molecules. Mono- and polyisotopomers are distinguished depending on the quantity of atoms of polyisotopic elements. Methodical approaches have been considered for the quantitative determination of the isotope composition of an element included in mono- and polyisotopic molecules. A possibility of the equally probable (homogeneous) and non-equally probable (non-homogeneous) distribution of isotopes of a polyisotopic element, the atoms of which have different positions in the molecule of polyisotopomer, has been shown. Factors disturbing the homogeneous distribution of isotopes of the element in the polyisotopomer pool have been revealed. When a polyisotopomer is involved in a mass-dependent process or reaction, the homogeneity of isotope distribution of the element is disturbed both in the residual and newly formed pools of polyisotopomer. By the example of CO 2 (polyisotopomer by oxygen) it has been shown that one can judge of the history of the analyzed pool formation by distribution of oxygen isotopes within this pool. The isotope content in the oxygen sites of polyisotopomer is a diagnostic feature of CO 2 involvement in the efflux from a reservoir or influx to the analyzed reservoir from an external source. (author)

  3. Enzymatic recognition of DNA replication origins

    International Nuclear Information System (INIS)

    Stayton, M.M.; Bertsch, L.; Biswas, S.

    1983-01-01

    In this paper we discuss the process of recognition of the complementary-strand origin with emphasis on RNA polymerase action in priming M13 DNA replication, the role of primase in G4 DNA replication, and the function of protein n, a priming protein, during primosome assembly. These phage systems do not require several of the bacterial DNA replication enzymes, particularly those involved in the regulation of chromosome copy number of the initiatiion of replication of duplex DNA. 51 references, 13 figures, 1 table

  4. Oxytocin Promotes Facial Emotion Recognition and Amygdala Reactivity in Adults with Asperger Syndrome

    Science.gov (United States)

    Domes, Gregor; Kumbier, Ekkehardt; Heinrichs, Markus; Herpertz, Sabine C

    2014-01-01

    The neuropeptide oxytocin has recently been shown to enhance eye gaze and emotion recognition in healthy men. Here, we report a randomized double-blind, placebo-controlled trial that examined the neural and behavioral effects of a single dose of intranasal oxytocin on emotion recognition in individuals with Asperger syndrome (AS), a clinical condition characterized by impaired eye gaze and facial emotion recognition. Using functional magnetic resonance imaging, we examined whether oxytocin would enhance emotion recognition from facial sections of the eye vs the mouth region and modulate regional activity in brain areas associated with face perception in both adults with AS, and a neurotypical control group. Intranasal administration of the neuropeptide oxytocin improved performance in a facial emotion recognition task in individuals with AS. This was linked to increased left amygdala reactivity in response to facial stimuli and increased activity in the neural network involved in social cognition. Our data suggest that the amygdala, together with functionally associated cortical areas mediate the positive effect of oxytocin on social cognitive functioning in AS. PMID:24067301

  5. The Importance of Recognition for Equal Representation in Participatory Processes: Lessons from Husby

    Directory of Open Access Journals (Sweden)

    Karin Hansson

    2014-08-01

    Full Text Available Despite the ambition to involve people on more equal terms, participation often still means that the audience is involved in clearly demarcated parts of the process and attempts to develop more deliberative democratic processes in urban planning often fail due to unequal representation in the participatory process.While sharing the general idea of the value of participatory processes, we will investigate some problematic features involved and suggest how some of these can be remedied. We employ the concept of recognition to analyse the conditions for public participation in a recent case of urban planning in the Stockholm suburb of Husby. This case is particularly interesting as it clearly demonstrates the impact of globalisation on local participatory processes.The results show the importance of broad recognition for equal representation in participatory processes, and the need for a plurality of public spheres to support long-term participation in the development of the common urban space.

  6. Pupil dilation during recognition memory: Isolating unexpected recognition from judgment uncertainty.

    Science.gov (United States)

    Mill, Ravi D; O'Connor, Akira R; Dobbins, Ian G

    2016-09-01

    Optimally discriminating familiar from novel stimuli demands a decision-making process informed by prior expectations. Here we demonstrate that pupillary dilation (PD) responses during recognition memory decisions are modulated by expectations, and more specifically, that pupil dilation increases for unexpected compared to expected recognition. Furthermore, multi-level modeling demonstrated that the time course of the dilation during each individual trial contains separable early and late dilation components, with the early amplitude capturing unexpected recognition, and the later trailing slope reflecting general judgment uncertainty or effort. This is the first demonstration that the early dilation response during recognition is dependent upon observer expectations and that separate recognition expectation and judgment uncertainty components are present in the dilation time course of every trial. The findings provide novel insights into adaptive memory-linked orienting mechanisms as well as the general cognitive underpinnings of the pupillary index of autonomic nervous system activity. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Electrostatic similarities between protein and small molecule ligands facilitate the design of protein-protein interaction inhibitors.

    Directory of Open Access Journals (Sweden)

    Arnout Voet

    Full Text Available One of the underlying principles in drug discovery is that a biologically active compound is complimentary in shape and molecular recognition features to its receptor. This principle infers that molecules binding to the same receptor may share some common features. Here, we have investigated whether the electrostatic similarity can be used for the discovery of small molecule protein-protein interaction inhibitors (SMPPIIs. We have developed a method that can be used to evaluate the similarity of electrostatic potentials between small molecules and known protein ligands. This method was implemented in a software called EleKit. Analyses of all available (at the time of research SMPPII structures indicate that SMPPIIs bear some similarities of electrostatic potential with the ligand proteins of the same receptor. This is especially true for the more polar SMPPIIs. Retrospective analysis of several successful SMPPIIs has shown the applicability of EleKit in the design of new SMPPIIs.

  8. Automatization and Orthographic Development in Second Language Visual Word Recognition

    Science.gov (United States)

    Kida, Shusaku

    2016-01-01

    The present study investigated second language (L2) learners' acquisition of automatic word recognition and the development of L2 orthographic representation in the mental lexicon. Participants in the study were Japanese university students enrolled in a compulsory course involving a weekly 30-minute sustained silent reading (SSR) activity with…

  9. The Central Role of Recognition in Auditory Perception: A Neurobiological Model

    Science.gov (United States)

    McLachlan, Neil; Wilson, Sarah

    2010-01-01

    The model presents neurobiologically plausible accounts of sound recognition (including absolute pitch), neural plasticity involved in pitch, loudness and location information integration, and streaming and auditory recall. It is proposed that a cortical mechanism for sound identification modulates the spectrotemporal response fields of inferior…

  10. [Construction of chemical information database based on optical structure recognition technique].

    Science.gov (United States)

    Lv, C Y; Li, M N; Zhang, L R; Liu, Z M

    2018-04-18

    To create a protocol that could be used to construct chemical information database from scientific literature quickly and automatically. Scientific literature, patents and technical reports from different chemical disciplines were collected and stored in PDF format as fundamental datasets. Chemical structures were transformed from published documents and images to machine-readable data by using the name conversion technology and optical structure recognition tool CLiDE. In the process of molecular structure information extraction, Markush structures were enumerated into well-defined monomer molecules by means of QueryTools in molecule editor ChemDraw. Document management software EndNote X8 was applied to acquire bibliographical references involving title, author, journal and year of publication. Text mining toolkit ChemDataExtractor was adopted to retrieve information that could be used to populate structured chemical database from figures, tables, and textual paragraphs. After this step, detailed manual revision and annotation were conducted in order to ensure the accuracy and completeness of the data. In addition to the literature data, computing simulation platform Pipeline Pilot 7.5 was utilized to calculate the physical and chemical properties and predict molecular attributes. Furthermore, open database ChEMBL was linked to fetch known bioactivities, such as indications and targets. After information extraction and data expansion, five separate metadata files were generated, including molecular structure data file, molecular information, bibliographical references, predictable attributes and known bioactivities. Canonical simplified molecular input line entry specification as primary key, metadata files were associated through common key nodes including molecular number and PDF number to construct an integrated chemical information database. A reasonable construction protocol of chemical information database was created successfully. A total of 174 research

  11. Regulated expression of the neural cell adhesion molecule L1 by specific patterns of neural impulses.

    Science.gov (United States)

    Itoh, K; Stevens, B; Schachner, M; Fields, R D

    1995-11-24

    Development of the mammalian nervous system is regulated by neural impulse activity, but the molecular mechanisms are not well understood. If cell recognition molecules [for example, L1 and the neural cell adhesion molecule (NCAM)] were influenced by specific patterns of impulse activity, cell-cell interactions controlling nervous system structure could be regulated by nervous system function at critical stages of development. Low-frequency electrical pulses delivered to mouse sensory neurons in culture (0.1 hertz for 5 days) down-regulated expression of L1 messenger RNA and protein (but not NCAM). Fasciculation of neurites, adhesion of neuroblastoma cells, and the number of Schwann cells on neurites was reduced after 0.1-hertz stimulation, but higher frequencies or stimulation after synaptogenesis were without effect.

  12. Structure of the C-type lectin carbohydrate recognition domain of human Tetranectin

    DEFF Research Database (Denmark)

    Kastrup, Jette Sandholm Jensen; Nielsen, Bettina Bryde; Rasmussen, Hanne B.

    1998-01-01

    Tetranectin (TN) is a C-type lectin involved in fibrinolysis, being the only endogenous ligand known to bind specifically to the kringle 4 domain of plasminogen. TN was originally isolated from plasma, but shows a wide tissue distribution. Furthermore, TN has been found in the extracellular matri...... molecules. One sulfate ion has been located at the surface of TN3, forming contacts to Glu120, Lys148, Asn106 of a symmetry-related molecule, and to an ethanol molecule....

  13. Relative preservation of the recognition of positive facial expression "happiness" in Alzheimer disease.

    Science.gov (United States)

    Maki, Yohko; Yoshida, Hiroshi; Yamaguchi, Tomoharu; Yamaguchi, Haruyasu

    2013-01-01

    Positivity recognition bias has been reported for facial expression as well as memory and visual stimuli in aged individuals, whereas emotional facial recognition in Alzheimer disease (AD) patients is controversial, with possible involvement of confounding factors such as deficits in spatial processing of non-emotional facial features and in verbal processing to express emotions. Thus, we examined whether recognition of positive facial expressions was preserved in AD patients, by adapting a new method that eliminated the influences of these confounding factors. Sensitivity of six basic facial expressions (happiness, sadness, surprise, anger, disgust, and fear) was evaluated in 12 outpatients with mild AD, 17 aged normal controls (ANC), and 25 young normal controls (YNC). To eliminate the factors related to non-emotional facial features, averaged faces were prepared as stimuli. To eliminate the factors related to verbal processing, the participants were required to match the images of stimulus and answer, avoiding the use of verbal labels. In recognition of happiness, there was no difference in sensitivity between YNC and ANC, and between ANC and AD patients. AD patients were less sensitive than ANC in recognition of sadness, surprise, and anger. ANC were less sensitive than YNC in recognition of surprise, anger, and disgust. Within the AD patient group, sensitivity of happiness was significantly higher than those of the other five expressions. In AD patient, recognition of happiness was relatively preserved; recognition of happiness was most sensitive and was preserved against the influences of age and disease.

  14. Lack of gender-specific antibody recognition of products from domains of a var gene implicated in pregnancy-associated Plasmodium falciparum malaria

    DEFF Research Database (Denmark)

    Jensen, Anja T R; Zornig, Hanne D; Buhmann, Caecilie

    2003-01-01

    Gender-specific and parity-dependent acquired antibody recognition is characteristic of variant surface antigens (VSA) expressed by chondroitin sulfate A (CSA)-adherent Plasmodium falciparum involved in pregnancy-associated malaria (PAM). However, antibody recognition of recombinant products...

  15. Speech recognition in natural background noise.

    Directory of Open Access Journals (Sweden)

    Julien Meyer

    Full Text Available In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR. Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A, reference at 1 meter at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB. Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda. Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for

  16. Speech recognition in natural background noise.

    Science.gov (United States)

    Meyer, Julien; Dentel, Laure; Meunier, Fanny

    2013-01-01

    In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR). Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A), reference at 1 meter) at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB). Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda). Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for future studies.

  17. Identification of a cytotoxic molecule in heat-modified citrus pectin.

    Science.gov (United States)

    Leclere, Lionel; Fransolet, Maude; Cambier, Pierre; El Bkassiny, Sandy; Tikad, Abdellatif; Dieu, Marc; Vincent, Stéphane P; Van Cutsem, Pierre; Michiels, Carine

    2016-02-10

    Modified forms of citrus pectin possess anticancer properties. However, their mechanism of action and the structural features involved remain unclear. Here, we showed that citrus pectin modified by heat treatment displayed cytotoxic effects in cancer cells. A fractionation approach was used aiming to identify active molecules. Dialysis and ethanol precipitation followed by HPLC analysis evidenced that most of the activity was related to molecules with molecular weight corresponding to low degree of polymerization oligogalacturonic acid. Heat-treatment of galacturonic acid also generated cytotoxic molecules. Furthermore, heat-modified galacturonic acid and heat-fragmented pectin contained the same molecule that induced cell death when isolated by HPLC separation. Mass spectrometry analyses revealed that 4,5-dihydroxy-2-cyclopenten-1-one was one cytotoxic molecule present in heat-treated pectin. Finally, we synthesized the enantiopure (4R,5R)-4,5-dihydroxy-2-cyclopenten-1-one and demonstrated that this molecule was cytotoxic and induced a similar pattern of apoptotic-like features than heat-modified pectin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. 3D Multi-Level Non-LTE Radiative Transfer for the CO Molecule

    Science.gov (United States)

    Berkner, A.; Schweitzer, A.; Hauschildt, P. H.

    2015-01-01

    The photospheres of cool stars are both rich in molecules and an environment where the assumption of LTE can not be upheld under all circumstances. Unfortunately, detailed 3D non-LTE calculations involving molecules are hardly feasible with current computers. For this reason, we present our implementation of the super level technique, in which molecular levels are combined into super levels, to reduce the number of unknowns in the rate equations and, thus, the computational effort and memory requirements involved, and show the results of our first tests against the 1D implementation of the same method.

  19. Fast Rotational Diffusion of Water Molecules in a 2D Hydrogen Bond Network at Cryogenic Temperatures

    Science.gov (United States)

    Prisk, T. R.; Hoffmann, C.; Kolesnikov, A. I.; Mamontov, E.; Podlesnyak, A. A.; Wang, X.; Kent, P. R. C.; Anovitz, L. M.

    2018-05-01

    Individual water molecules or small clusters of water molecules contained within microporous minerals present an extreme case of confinement where the local structure of hydrogen bond networks are dramatically altered from bulk water. In the zinc silicate hemimorphite, the water molecules form a two-dimensional hydrogen bond network with hydroxyl groups in the crystal framework. Here, we present a combined experimental and theoretical study of the structure and dynamics of water molecules within this network. The water molecules undergo a continuous phase transition in their orientational configuration analogous to a two-dimensional Ising model. The incoherent dynamic structure factor reveals two thermally activated relaxation processes, one on a subpicosecond timescale and another on a 10-100 ps timescale, between 70 and 130 K. The slow process is an in-plane reorientation of the water molecule involving the breaking of hydrogen bonds with a framework that, despite the low temperatures involved, is analogous to rotational diffusion of water molecules in the bulk liquid. The fast process is a localized motion of the water molecule with no apparent analogs among known bulk or confined phases of water.

  20. Dust-forming molecules in VY Canis Majoris (and Betelgeuse)

    OpenAIRE

    Kaminski, T.; Gottlieb, C. A.; Schmidt, M. R.; Patel, N. A.; Young, K. H.; Menten, K. M.; Brunken, S.; Muller, H. S. P.; Winters, J. M.; McCarthy, M. C.

    2013-01-01

    The formation of inorganic dust in circumstellar environments of evolved stars is poorly understood. Spectra of molecules thought to be most important for the nucleation, i.e. AlO, TiO, and TiO2, have been recently detected in the red supergiant VY CMa. These molecules are effectively formed in VY CMa and the observations suggest that non-equilibrium chemistry must be involved in their formation and nucleation into dust. In addition to exploring the recent observations of VY CMa, we briefly d...

  1. Growing interstellar molecules with ion-molecule reactions

    International Nuclear Information System (INIS)

    Bohme, D.K.

    1989-01-01

    Laboratory measurements of gas-phase ion-molecule reactions continue to provide important insights into the chemistry of molecular growth in interstellar environments. It is also true that the measurements are becoming more demanding as larger molecules capture our interest. While some of these measurements are motivated by current developments in chemical models of interstellar environments or by new molecular observations by astronomers, others explore novel chemistry which can lead to predictions of new interstellar molecules. Here the author views the results of some recent measurements, taken in the Ion Chemistry Laboratory at York University with the SIFT technique, which address some of the current needs of modellers and observers and which also provide some new fundamental insight into molecular growth, particularly when it occurs in the presence of large molecules such as PAH molecules which are now thought to have a major influence on the chemistry of interstellar environments in which they are present

  2. Herpesvirus Genome Recognition Induced Acetylation of Nuclear IFI16 Is Essential for Its Cytoplasmic Translocation, Inflammasome and IFN-β Responses.

    Directory of Open Access Journals (Sweden)

    Mairaj Ahmed Ansari

    2015-07-01

    Full Text Available The IL-1β and type I interferon-β (IFN-β molecules are important inflammatory cytokines elicited by the eukaryotic host as innate immune responses against invading pathogens and danger signals. Recently, a predominantly nuclear gamma-interferon-inducible protein 16 (IFI16 involved in transcriptional regulation has emerged as an innate DNA sensor which induced IL-1β and IFN-β production through inflammasome and STING activation, respectively. Herpesvirus (KSHV, EBV, and HSV-1 episomal dsDNA genome recognition by IFI16 leads to IFI16-ASC-procaspase-1 inflammasome association, cytoplasmic translocation and IL-1β production. Independent of ASC, HSV-1 genome recognition results in IFI16 interaction with STING in the cytoplasm to induce interferon-β production. However, the mechanisms of IFI16-inflammasome formation, cytoplasmic redistribution and STING activation are not known. Our studies here demonstrate that recognition of herpesvirus genomes in the nucleus by IFI16 leads into its interaction with histone acetyltransferase p300 and IFI16 acetylation resulting in IFI16-ASC interaction, inflammasome assembly, increased interaction with Ran-GTPase, cytoplasmic redistribution, caspase-1 activation, IL-1β production, and interaction with STING which results in IRF-3 phosphorylation, nuclear pIRF-3 localization and interferon-β production. ASC and STING knockdowns did not affect IFI16 acetylation indicating that this modification is upstream of inflammasome-assembly and STING-activation. Vaccinia virus replicating in the cytoplasm did not induce nuclear IFI16 acetylation and cytoplasmic translocation. IFI16 physically associates with KSHV and HSV-1 genomes as revealed by proximity ligation microscopy and chromatin-immunoprecipitation studies which is not hampered by the inhibition of acetylation, thus suggesting that acetylation of IFI16 is not required for its innate sensing of nuclear viral genomes. Collectively, these studies identify the

  3. Remote control of therapeutic T cells through a small molecule-gated chimeric receptor

    Science.gov (United States)

    Wu, Chia-Yung; Roybal, Kole T.; Puchner, Elias M.; Onuffer, James; Lim, Wendell A.

    2016-01-01

    There is growing promise in using engineered cells as therapeutic agents. For example, synthetic Chimeric Antigen Receptors (CARs) can redirect T cells to recognize and eliminate tumor cells expressing specific antigens. Despite promising clinical results, excessive activity and poor control over such engineered T cells can cause severe toxicities. We present the design of “ON-switch” CARs that enable small molecule-control over T cell therapeutic functions, while still retaining antigen specificity. In these split receptors, antigen binding and intracellular signaling components only assemble in the presence of a heterodimerizing small molecule. This titratable pharmacologic regulation could allow physicians to precisely control the timing, location, and dosage of T cell activity, thereby mitigating toxicity. This work illustrates the potential of combining cellular engineering with orthogonal chemical tools to yield safer therapeutic cells that tightly integrate both cell autonomous recognition and user control. PMID:26405231

  4. Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

    OpenAIRE

    Park, Young Ho; Park, Kang Ryoung

    2012-01-01

    On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger‐vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger‐vein recognition is advantageous in that it involves the use of inexpensive and small devices that are diffic...

  5. Engineering responsive polymer building blocks with host-guest molecular recognition for functional applications.

    Science.gov (United States)

    Hu, Jinming; Liu, Shiyong

    2014-07-15

    CONSPECTUS: All living organisms and soft matter are intrinsically responsive and adaptive to external stimuli. Inspired by this fact, tremendous effort aiming to emulate subtle responsive features exhibited by nature has spurred the invention of a diverse range of responsive polymeric materials. Conventional stimuli-responsive polymers are constructed via covalent bonds and can undergo reversible or irreversible changes in chemical structures, physicochemical properties, or both in response to a variety of external stimuli. They have been imparted with a variety of emerging applications including drug and gene delivery, optical sensing and imaging, diagnostics and therapies, smart coatings and textiles, and tissue engineering. On the other hand, in comparison with molecular chemistry held by covalent bonds, supramolecular chemistry built on weak and reversible noncovalent interactions has emerged as a powerful and versatile strategy for materials fabrication due to its facile accessibility, extraordinary reversibility and adaptivity, and potent applications in diverse fields. Typically involving more than one type of noncovalent interactions (e.g., hydrogen bonding, metal coordination, hydrophobic association, electrostatic interactions, van der Waals forces, and π-π stacking), host-guest recognition refers to the formation of supramolecular inclusion complexes between two or more entities connected together in a highly controlled and cooperative manner. The inherently reversible and adaptive nature of host-guest molecular recognition chemistry, stemming from multiple noncovalent interactions, has opened up a new platform to construct novel types of stimuli-responsive materials. The introduction of host-guest chemistry not only enriches the realm of responsive materials but also confers them with promising new applications. Most intriguingly, the integration of responsive polymer building blocks with host-guest recognition motifs will endow the former with

  6. Torque Measurement at the Single Molecule Level

    Science.gov (United States)

    Forth, Scott; Sheinin, Maxim Y.; Inman, James; Wang, Michelle D.

    2017-01-01

    Methods for exerting and measuring forces on single molecules have revolutionized the study of the physics of biology. However, it is often the case that biological processes involve rotation or torque generation, and these parameters have been more difficult to access experimentally. Recent advances in the single molecule field have led to the development of techniques which add the capability of torque measurement. By combining force, displacement, torque, and rotational data, a more comprehensive description of the mechanics of a biomolecule can be achieved. In this review, we highlight a number of biological processes for which torque plays a key mechanical role. We describe the various techniques that have been developed to directly probe the torque experienced by a single molecule, and detail a variety of measurements made to date using these new technologies. We conclude by discussing a number of open questions and propose systems of study which would be well suited for analysis with torsional measurement techniques. PMID:23541162

  7. Single-molecule imaging and manipulation of biomolecular machines and systems.

    Science.gov (United States)

    Iino, Ryota; Iida, Tatsuya; Nakamura, Akihiko; Saita, Ei-Ichiro; You, Huijuan; Sako, Yasushi

    2018-02-01

    Biological molecular machines support various activities and behaviors of cells, such as energy production, signal transduction, growth, differentiation, and migration. We provide an overview of single-molecule imaging methods involving both small and large probes used to monitor the dynamic motions of molecular machines in vitro (purified proteins) and in living cells, and single-molecule manipulation methods used to measure the forces, mechanical properties and responses of biomolecules. We also introduce several examples of single-molecule analysis, focusing primarily on motor proteins and signal transduction systems. Single-molecule analysis is a powerful approach to unveil the operational mechanisms both of individual molecular machines and of systems consisting of many molecular machines. Quantitative, high-resolution single-molecule analyses of biomolecular systems at the various hierarchies of life will help to answer our fundamental question: "What is life?" This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. A biologically inspired neural network model to transformation invariant object recognition

    Science.gov (United States)

    Iftekharuddin, Khan M.; Li, Yaqin; Siddiqui, Faraz

    2007-09-01

    Transformation invariant image recognition has been an active research area due to its widespread applications in a variety of fields such as military operations, robotics, medical practices, geographic scene analysis, and many others. The primary goal for this research is detection of objects in the presence of image transformations such as changes in resolution, rotation, translation, scale and occlusion. We investigate a biologically-inspired neural network (NN) model for such transformation-invariant object recognition. In a classical training-testing setup for NN, the performance is largely dependent on the range of transformation or orientation involved in training. However, an even more serious dilemma is that there may not be enough training data available for successful learning or even no training data at all. To alleviate this problem, a biologically inspired reinforcement learning (RL) approach is proposed. In this paper, the RL approach is explored for object recognition with different types of transformations such as changes in scale, size, resolution and rotation. The RL is implemented in an adaptive critic design (ACD) framework, which approximates the neuro-dynamic programming of an action network and a critic network, respectively. Two ACD algorithms such as Heuristic Dynamic Programming (HDP) and Dual Heuristic dynamic Programming (DHP) are investigated to obtain transformation invariant object recognition. The two learning algorithms are evaluated statistically using simulated transformations in images as well as with a large-scale UMIST face database with pose variations. In the face database authentication case, the 90° out-of-plane rotation of faces from 20 different subjects in the UMIST database is used. Our simulations show promising results for both designs for transformation-invariant object recognition and authentication of faces. Comparing the two algorithms, DHP outperforms HDP in learning capability, as DHP takes fewer steps to

  9. Ia-restricted B-B cell interaction. I. The MHC haplotype of bone marrow cells present during B cell ontogeny dictates the self-recognition specificity of B cells in the polyclonal B cell activation by a B cell differentiation factor, B151-TRF2

    International Nuclear Information System (INIS)

    Ono, S.; Takahama, Y.; Hamaoka, T.

    1987-01-01

    We have demonstrated that B cell recognition of Ia molecules is involved in polyclonal B cell differentiation by B151-TRF2. The present study was undertaken to examine the Ia recognition specificity of B151-TRF2-responsive B cells in fully major histocompatibility complex (MHC)-allogeneic P1----P2, semiallogeneic P1----(P1 x P2)F1, and double donor (P1 + P2)----(P1 x P2)F1 and (P1 + P2)----P1 radiation bone marrow chimeras. The B cells from both P1----P2 and P1----(P1 x P2)F1 chimeras could give rise to in vitro immunoglobulin M-producing cells upon stimulation with B151-TRF2 comparable in magnitude to that of normal P1 B cells, and their responses were inhibited by anti-I-AP1 but not by anti-I-AP2 monoclonal antibody even in the presence of mitomycin C-treated T cell-depleted P2 spleen cells as auxiliary cells. In contrast, the B151-TRF2 responses of P1 B cells isolated from both (P1 + P2)----(P1 x P2)F1 and (P1 + P2)----P1 double bone marrow chimeras became sensitive to the inhibition of not only anti-I-AP1 but also anti-I-AP2 monoclonal antibody only when the culture was conducted in the presence of P2 auxiliary cells, demonstrating that they adaptively differentiate to recognize as self-structures allogeneic as well as syngeneic Ia molecules. Moreover, the experiments utilizing B cells from H-2-congenic mice and B cell hybridoma clones as auxiliary cells revealed that B151-TRF2-responsive B cells recognize Ia molecules expressed on B cells. Taken together, these results demonstrate that B151-TRF2-responsive B cells recognize Ia molecules expressed by B cells as self-structures and that their self-recognition specificity is dictated by the MHC haplotype of bone marrow cells present during the B cell ontogeny but not by the MHC haplotype of a radiation-resistant host environment

  10. Static and dynamic 3D facial expression recognition: A comprehensive survey

    NARCIS (Netherlands)

    Sandbach, G.; Zafeiriou, S.; Pantic, Maja; Yin, Lijun

    2012-01-01

    Automatic facial expression recognition constitutes an active research field due to the latest advances in computing technology that make the user's experience a clear priority. The majority of work conducted in this area involves 2D imagery, despite the problems this presents due to inherent pose

  11. Complex Human Activity Recognition Using Smartphone and Wrist-Worn Motion Sensors

    NARCIS (Netherlands)

    Shoaib, M.; Bosch, S.; Durmaz, O.; Scholten, Johan; Havinga, Paul J.M.

    2016-01-01

    The position of on-body motion sensors plays an important role in human activity recognition. Most often, mobile phone sensors at the trouser pocket or an equivalent position are used for this purpose. However, this position is not suitable for recognizing activities that involve hand gestures, such

  12. Recognition memory for vibrotactile rhythms: an fMRI study in blind and sighted individuals.

    Science.gov (United States)

    Sinclair, Robert J; Dixit, Sachin; Burton, Harold

    2011-01-01

    Calcarine sulcal cortex possibly contributes to semantic recognition memory in early blind (EB). We assessed a recognition memory role using vibrotactile rhythms and a retrieval success paradigm involving learned "old" and "new" rhythms in EB and sighted. EB showed no activation differences in occipital cortex indicating retrieval success but replicated findings of somatosensory processing. Both groups showed retrieval success in primary somatosensory, precuneus, and orbitofrontal cortex. The S1 activity might indicate generic sensory memory processes.

  13. iBodies: modular synthetic antibody mimetics based on hydrophilic polymers decorated with functional moieties as tools for molecular recognition, imaging and specific drug delivery

    Czech Academy of Sciences Publication Activity Database

    Šácha, Pavel; Dvořáková, Petra; Knedlík, Tomáš; Schimer, Jiří; Šubr, Vladimír; Ulbrich, Karel; Bušek, P.; Navrátil, Václav; Sedlák, František; Majer, Pavel; Šedo, A.; Konvalinka, Jan

    2017-01-01

    Roč. 284, Suppl 1 (2017), s. 340 ISSN 1742-464X. [FEBS Congress /42./ From Molecules to Cells and Back. 10.09.2017-14.09.2017, Jerusalem] Institutional support: RVO:61388963 ; RVO:61389013 Keywords : antibody mimetics * molecular recognition * polymer conjugates Subject RIV: CE - Biochemistry

  14. Sudden Event Recognition: A Survey

    Directory of Open Access Journals (Sweden)

    Mohd Asyraf Zulkifley

    2013-08-01

    Full Text Available 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.

  15. Transfer mechanisms between emitter molecules for OLED applications

    Energy Technology Data Exchange (ETDEWEB)

    Steinbacher, Frank [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Chiu, Chien-Shu [Department of Electrical Engineering and Information Technology, Technical University of Braunschweig (Germany); Siemens AG, CT MM 1, Erlangen (Germany); Krause, Ralf; Hunze, Arvid [Siemens AG, CT MM 1, Erlangen (Germany); Winnacker, Albrecht [Department of Materials Science VI, University of Erlangen-Nuernberg (Germany)

    2009-07-01

    Within the last few years white organic light emitting diodes based on small molecules have shown the potential to have a promising future in the field of lighting technology. Nevertheless there is still room for improvement of the overall efficiency and lifetime of white OLEDs. A deeper understanding of the energy transfer mechanisms between different matrix and emitter molecules used in the OLED stack concept can help to optimize the layout and reduce driving voltage thus increasing the power efficiency and color stability of the device. To simplify the complex interactions within a complete white OLED we start out with a basic model system only containing the molecules of interest. This enables us to predict the fundamental concepts causing the behavior of more intricate systems. Using photoluminescence, excitation spectra and time-resolved photoluminescence we investigated the exciton transfer between different dyes for a variety of emitter systems. Our results indicate a dependence of exciton transfer probability on the total concentrations and therefore the distance between the molecules involved.

  16. Individual differences in forced-choice recognition memory: partitioning contributions of recollection and familiarity.

    Science.gov (United States)

    Migo, Ellen M; Quamme, Joel R; Holmes, Selina; Bendell, Andrew; Norman, Kenneth A; Mayes, Andrew R; Montaldi, Daniela

    2014-01-01

    In forced-choice recognition memory, two different testing formats are possible under conditions of high target-foil similarity: Each target can be presented alongside foils similar to itself (forced-choice corresponding; FCC), or alongside foils similar to other targets (forced-choice noncorresponding; FCNC). Recent behavioural and neuropsychological studies suggest that FCC performance can be supported by familiarity whereas FCNC performance is supported primarily by recollection. In this paper, we corroborate this finding from an individual differences perspective. A group of older adults were given a test of FCC and FCNC recognition for object pictures, as well as standardized tests of recall, recognition, and IQ. Recall measures were found to predict FCNC, but not FCC performance, consistent with a critical role for recollection in FCNC only. After the common influence of recall was removed, standardized tests of recognition predicted FCC, but not FCNC performance. This is consistent with a contribution of only familiarity in FCC. Simulations show that a two-process model, where familiarity and recollection make separate contributions to recognition, is 10 times more likely to give these results than a single-process model. This evidence highlights the importance of recognition memory test design when examining the involvement of recollection and familiarity.

  17. Multimodal Emotion Recognition Is Resilient to Insufficient Sleep: Results From Cross-Sectional and Experimental Studies.

    Science.gov (United States)

    Holding, Benjamin C; Laukka, Petri; Fischer, Håkan; Bänziger, Tanja; Axelsson, John; Sundelin, Tina

    2017-11-01

    Insufficient sleep has been associated with impaired recognition of facial emotions. However, previous studies have found inconsistent results, potentially stemming from the type of static picture task used. We therefore examined whether insufficient sleep was associated with decreased emotion recognition ability in two separate studies using a dynamic multimodal task. Study 1 used a cross-sectional design consisting of 291 participants with questionnaire measures assessing sleep duration and self-reported sleep quality for the previous night. Study 2 used an experimental design involving 181 participants where individuals were quasi-randomized into either a sleep-deprivation (N = 90) or a sleep-control (N = 91) condition. All participants from both studies were tested on the same forced-choice multimodal test of emotion recognition to assess the accuracy of emotion categorization. Sleep duration, self-reported sleep quality (study 1), and sleep deprivation (study 2) did not predict overall emotion recognition accuracy or speed. Similarly, the responses to each of the twelve emotions tested showed no evidence of impaired recognition ability, apart from one positive association suggesting that greater self-reported sleep quality could predict more accurate recognition of disgust (study 1). The studies presented here involve considerably larger samples than previous studies and the results support the null hypotheses. Therefore, we suggest that the ability to accurately categorize the emotions of others is not associated with short-term sleep duration or sleep quality and is resilient to acute periods of insufficient sleep. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  18. Learning and Recognition of a Non-conscious Sequence of Events in Human Primary Visual Cortex.

    Science.gov (United States)

    Rosenthal, Clive R; Andrews, Samantha K; Antoniades, Chrystalina A; Kennard, Christopher; Soto, David

    2016-03-21

    Human primary visual cortex (V1) has long been associated with learning simple low-level visual discriminations [1] and is classically considered outside of neural systems that support high-level cognitive behavior in contexts that differ from the original conditions of learning, such as recognition memory [2, 3]. Here, we used a novel fMRI-based dichoptic masking protocol-designed to induce activity in V1, without modulation from visual awareness-to test whether human V1 is implicated in human observers rapidly learning and then later (15-20 min) recognizing a non-conscious and complex (second-order) visuospatial sequence. Learning was associated with a change in V1 activity, as part of a temporo-occipital and basal ganglia network, which is at variance with the cortico-cerebellar network identified in prior studies of "implicit" sequence learning that involved motor responses and visible stimuli (e.g., [4]). Recognition memory was associated with V1 activity, as part of a temporo-occipital network involving the hippocampus, under conditions that were not imputable to mechanisms associated with conscious retrieval. Notably, the V1 responses during learning and recognition separately predicted non-conscious recognition memory, and functional coupling between V1 and the hippocampus was enhanced for old retrieval cues. The results provide a basis for novel hypotheses about the signals that can drive recognition memory, because these data (1) identify human V1 with a memory network that can code complex associative serial visuospatial information and support later non-conscious recognition memory-guided behavior (cf. [5]) and (2) align with mouse models of experience-dependent V1 plasticity in learning and memory [6]. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Computational analysis of protein-protein interfaces involving an alpha helix: insights for terphenyl-like molecules binding.

    Science.gov (United States)

    Isvoran, Adriana; Craciun, Dana; Martiny, Virginie; Sperandio, Olivier; Miteva, Maria A

    2013-06-14

    Protein-Protein Interactions (PPIs) are key for many cellular processes. The characterization of PPI interfaces and the prediction of putative ligand binding sites and hot spot residues are essential to design efficient small-molecule modulators of PPI. Terphenyl and its derivatives are small organic molecules known to mimic one face of protein-binding alpha-helical peptides. In this work we focus on several PPIs mediated by alpha-helical peptides. We performed computational sequence- and structure-based analyses in order to evaluate several key physicochemical and surface properties of proteins known to interact with alpha-helical peptides and/or terphenyl and its derivatives. Sequence-based analysis revealed low sequence identity between some of the analyzed proteins binding alpha-helical peptides. Structure-based analysis was performed to calculate the volume, the fractal dimension roughness and the hydrophobicity of the binding regions. Besides the overall hydrophobic character of the binding pockets, some specificities were detected. We showed that the hydrophobicity is not uniformly distributed in different alpha-helix binding pockets that can help to identify key hydrophobic hot spots. The presence of hydrophobic cavities at the protein surface with a more complex shape than the entire protein surface seems to be an important property related to the ability of proteins to bind alpha-helical peptides and low molecular weight mimetics. Characterization of similarities and specificities of PPI binding sites can be helpful for further development of small molecules targeting alpha-helix binding proteins.

  20. Contrasting roles for DNA methyltransferases and histone deacetylases in single-item and associative recognition memory.

    Science.gov (United States)

    Scott, Hannah; Smith, Anna E; Barker, Gareth R; Uney, James B; Warburton, E Clea

    2017-03-01

    Recognition memory enables us to judge whether we have encountered a stimulus before and to recall associated information, including where the stimulus was encountered. The perirhinal cortex (PRh) is required for judgment of stimulus familiarity, while hippocampus (HPC) and medial prefrontal cortex (mPFC) are additionally involved when spatial information associated with a stimulus needs to be remembered. While gene expression is known to be essential for the consolidation of long-term recognition memory, the underlying regulatory mechanisms are not fully understood. Here we investigated the roles of two epigenetic mechanisms, DNA methylation and histone deacetylation, in recognition memory. Infusion of DNA methyltransferase inhibitors into PRh impaired performance in novel object recognition and object-in-place tasks while infusions into HPC or mPFC impaired object-in-place performance only. In contrast, inhibition of histone deacetylases in PRh, but not mPFC, enhanced recognition memory. These results support the emerging role of epigenetic processes in learning and memory.

  1. Contrasting roles for DNA methyltransferases and histone deacetylases in single-item and associative recognition memory

    Directory of Open Access Journals (Sweden)

    Hannah Scott

    2017-03-01

    Full Text Available Recognition memory enables us to judge whether we have encountered a stimulus before and to recall associated information, including where the stimulus was encountered. The perirhinal cortex (PRh is required for judgment of stimulus familiarity, while hippocampus (HPC and medial prefrontal cortex (mPFC are additionally involved when spatial information associated with a stimulus needs to be remembered. While gene expression is known to be essential for the consolidation of long-term recognition memory, the underlying regulatory mechanisms are not fully understood. Here we investigated the roles of two epigenetic mechanisms, DNA methylation and histone deacetylation, in recognition memory. Infusion of DNA methyltransferase inhibitors into PRh impaired performance in novel object recognition and object-in-place tasks while infusions into HPC or mPFC impaired object-in-place performance only. In contrast, inhibition of histone deacetylases in PRh, but not mPFC, enhanced recognition memory. These results support the emerging role of epigenetic processes in learning and memory.

  2. Recognition of lyso-phospholipids by human natural killer T lymphocytes.

    Directory of Open Access Journals (Sweden)

    Lisa M Fox

    2009-10-01

    Full Text Available Natural killer T (NKT cells are a subset of T lymphocytes with potent immunoregulatory properties. Recognition of self-antigens presented by CD1d molecules is an important route of NKT cell activation; however, the molecular identity of specific autoantigens that stimulate human NKT cells remains unclear. Here, we have analyzed human NKT cell recognition of CD1d cellular ligands. The most clearly antigenic species was lyso-phosphatidylcholine (LPC. Diacylated phosphatidylcholine and lyso-phosphoglycerols differing in the chemistry of the head group stimulated only weak responses from human NKT cells. However, lyso-sphingomyelin, which shares the phosphocholine head group of LPC, also activated NKT cells. Antigen-presenting cells pulsed with LPC were capable of stimulating increased cytokine responses by NKT cell clones and by freshly isolated peripheral blood lymphocytes. These results demonstrate that human NKT cells recognize cholinated lyso-phospholipids as antigens presented by CD1d. Since these lyso-phospholipids serve as lipid messengers in normal physiological processes and are present at elevated levels during inflammatory responses, these findings point to a novel link between NKT cells and cellular signaling pathways that are associated with human disease pathophysiology.

  3. Changing facial affect recognition in schizophrenia: Effects of training on brain dynamics

    Directory of Open Access Journals (Sweden)

    Petia Popova

    2014-01-01

    Full Text Available Deficits in social cognition including facial affect recognition and their detrimental effects on functional outcome are well established in schizophrenia. Structured training can have substantial effects on social cognitive measures including facial affect recognition. Elucidating training effects on cortical mechanisms involved in facial affect recognition may identify causes of dysfunctional facial affect recognition in schizophrenia and foster remediation strategies. In the present study, 57 schizophrenia patients were randomly assigned to (a computer-based facial affect training that focused on affect discrimination and working memory in 20 daily 1-hour sessions, (b similarly intense, targeted cognitive training on auditory-verbal discrimination and working memory, or (c treatment as usual. Neuromagnetic activity was measured before and after training during a dynamic facial affect recognition task (5 s videos showing human faces gradually changing from neutral to fear or to happy expressions. Effects on 10–13 Hz (alpha power during the transition from neutral to emotional expressions were assessed via MEG based on previous findings that alpha power increase is related to facial affect recognition and is smaller in schizophrenia than in healthy subjects. Targeted affect training improved overt performance on the training tasks. Moreover, alpha power increase during the dynamic facial affect recognition task was larger after affect training than after treatment-as-usual, though similar to that after targeted perceptual–cognitive training, indicating somewhat nonspecific benefits. Alpha power modulation was unrelated to general neuropsychological test performance, which improved in all groups. Results suggest that specific neural processes supporting facial affect recognition, evident in oscillatory phenomena, are modifiable. This should be considered when developing remediation strategies targeting social cognition in schizophrenia.

  4. Ethanol and Caffeine Effects on Social Interaction and Recognition in Mice: Involvement of Adenosine A2A and A1 Receptors.

    Science.gov (United States)

    López-Cruz, Laura; San-Miguel, Noemí; Bayarri, Pilar; Baqi, Younis; Müller, Christa E; Salamone, John D; Correa, Mercé

    2016-01-01

    Ethanol and caffeine are frequently consumed in combination and have opposite effects on the adenosine system: ethanol metabolism leads to an increase in adenosine levels, while caffeine is a non-selective adenosine A 1 /A 2A receptor antagonist. These receptors are highly expressed in striatum and olfactory tubercle, brain areas involved in exploration and social interaction in rodents. Ethanol modulates social interaction processes, but the role of adenosine in social behavior is still poorly understood. The present work was undertaken to study the impact of ethanol, caffeine and their combination on social behavior, and to explore the involvement of A 1 and A 2A receptors on those actions. Male CD1 mice were evaluated in a social interaction three-chamber paradigm, for preference of conspecific vs. object, and also for long-term recognition memory of familiar vs. novel conspecific. Ethanol showed a biphasic effect, with low doses (0.25 g/kg) increasing social contact and higher doses (1.0-1.5 g/kg) reducing social interaction. However, no dose changed social preference; mice always spent more time sniffing the conspecific than the object, independently of the ethanol dose. Ethanol, even at doses that did not change social exploration, produced amnestic effects on social recognition the following day. Caffeine reduced social contact (15.0-60.0 mg/kg), and even blocked social preference at higher doses (30.0-60.0 mg/kg). The A 1 antagonist Cyclopentyltheophylline (CPT; 3-9 mg/kg) did not modify social contact or preference on its own, and the A 2A antagonist MSX-3 (1.5-6 mg/kg) increased social interaction at all doses. Ethanol at intermediate doses (0.5-1.0 g/kg) was able to reverse the reduction in social exploration induced by caffeine (15.0-30.0 mg/kg). Although there was no interaction between ethanol and CPT or MSX-3 on social exploration in the first day, MSX-3 blocked the amnestic effects of ethanol observed on the following day. Thus, ethanol impairs the

  5. The Improvement of Behavior Recognition Accuracy of Micro Inertial Accelerometer by Secondary Recognition Algorithm

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2014-05-01

    Full Text Available Behaviors of “still”, “walking”, “running”, “jumping”, “upstairs” and “downstairs” can be recognized by micro inertial accelerometer of low cost. By using the features as inputs to the well-trained BP artificial neural network which is selected as classifier, those behaviors can be recognized. But the experimental results show that the recognition accuracy is not satisfactory. This paper presents secondary recognition algorithm and combine it with BP artificial neural network to improving the recognition accuracy. The Algorithm is verified by the Android mobile platform, and the recognition accuracy can be improved more than 8 %. Through extensive testing statistic analysis, the recognition accuracy can reach 95 % through BP artificial neural network and the secondary recognition, which is a reasonable good result from practical point of view.

  6. Small Molecule Library Synthesis Using Segmented Flow

    Directory of Open Access Journals (Sweden)

    Christina M. Thompson

    2011-11-01

    Full Text Available Flow chemistry has gained considerable recognition as a simple, efficient, and safe technology for the synthesis of many types of organic and inorganic molecules ranging in scope from large complex natural products to silicon nanoparticles. In this paper we describe a method that adapts flow chemistry to the synthesis of libraries of compounds using a fluorous immiscible solvent as a spacer between reactions. The methodology was validated in the synthesis of two small heterocycle containing libraries. The reactions were performed on a 0.2 mmol scale, enabling tens of milligrams of material to be generated in a single 200 mL reaction plug. The methodology allowed library synthesis in half the time of conventional microwave synthesis while maintaining similar yields. The ability to perform multiple, potentially unrelated reactions in a single run is ideal for making small quantities of many different compounds quickly and efficiently.

  7. Molecule nanoweaver

    Science.gov (United States)

    Gerald, II; Rex, E [Brookfield, IL; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL; Diaz, Rocio [Chicago, IL; Vukovic, Lela [Westchester, IL

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  8. Pharmacology of cell adhesion molecules of the nervous system

    DEFF Research Database (Denmark)

    Kiryushko, Darya; Bock, Elisabeth; Berezin, Vladimir

    2007-01-01

    Cell adhesion molecules (CAMs) play a pivotal role in the development and maintenance of the nervous system under normal conditions. They also are involved in numerous pathological processes such as inflammation, degenerative disorders, and cancer, making them attractive targets for drug...

  9. Molecular imprinting polymer electrosensor based on gold nanoparticles for theophylline recognition and determination

    International Nuclear Information System (INIS)

    Kan, X.; Liu, T.; Zhou, H.; Li, C.; Fang, B.

    2010-01-01

    An electrochemical sensor for theophylline (ThPh) was prepared by electropolymerizing o-phenylenediamine on a glassy carbon electrode in the presence of ThPh via cyclic voltammetry, followed by deposition of gold nanoparticles using a potentiostatic method. The effects of pH, ratio between template molecule and monomer, number of cycles for electropolymerization, and of the solution for extraction were optimized. The current of the electro-active model system hexacyanoferrate(III) and hexacyanoferrate(IV) decreased linearly with successive addition of ThPh in the concentration range between 4. 0 x 10 -7 ∼ 1. 5 x 10 -5 mol.L -1 and 2. 4 x 10 -4 ∼ 3. 4 x 10 -3 mol.L -1 , with a detection limit of 1. 0 x 10 -7 mol.L -1 . The sensor has an excellent recognition capability for ThPh compared to structurally related molecules, can be regenerated and is stable. (author)

  10. An fMRI study of concreteness effects in spoken word recognition.

    Science.gov (United States)

    Roxbury, Tracy; McMahon, Katie; Copland, David A

    2014-09-30

    Evidence for the brain mechanisms recruited when processing concrete versus abstract concepts has been largely derived from studies employing visual stimuli. The tasks and baseline contrasts used have also involved varying degrees of lexical processing. This study investigated the neural basis of the concreteness effect during spoken word recognition and employed a lexical decision task with a novel pseudoword condition. The participants were seventeen healthy young adults (9 females). The stimuli consisted of (a) concrete, high imageability nouns, (b) abstract, low imageability nouns and (c) opaque legal pseudowords presented in a pseudorandomised, event-related design. Activation for the concrete, abstract and pseudoword conditions was analysed using anatomical regions of interest derived from previous findings of concrete and abstract word processing. Behaviourally, lexical decision reaction times for the concrete condition were significantly faster than both abstract and pseudoword conditions and the abstract condition was significantly faster than the pseudoword condition (p word recognition. Significant activity was also elicited by concrete words relative to pseudowords in the left fusiform and left anterior middle temporal gyrus. These findings confirm the involvement of a widely distributed network of brain regions that are activated in response to the spoken recognition of concrete but not abstract words. Our findings are consistent with the proposal that distinct brain regions are engaged as convergence zones and enable the binding of supramodal input.

  11. Survey Analysis on Nuclear Security Culture Recognition of Nuclear Facility in 2014

    International Nuclear Information System (INIS)

    Hong, Yunjeong; Lee, Jeongho; Kim, Jaekwang

    2015-01-01

    All organizations involved in implementing physical protection should give due priority to the security culture, to its development and maintenance necessary to ensure its effective implementation in the entire organization. In this context, Korea Institute of Non-proliferation and Control(KINAC) confirms recognition about protection of people who work in nuclear field and developed questionnaire for utilizing fundamental data for nuclear security culture enhancement activity and conducted a survey. As a result, systematic education needs to employees. Choosing differentiated topic is required to consider employees because recognition level of age, position and division is different. And a variety of education technology as obligatory education such as filling the course time or the one-off thing has limitation. And taking complementary measures needs since there were many opinions that employees feel difficult to understand papers such as regulation and guidelines and so on related security. Finally, we hope to make fundament available to evaluate nuclear security culture recognition level based on the existing questionnaire would be changed to realistic and enhancement in recognition survey for future nuclear security culture

  12. Survey Analysis on Nuclear Security Culture Recognition of Nuclear Facility in 2014

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Yunjeong; Lee, Jeongho; Kim, Jaekwang [Korea Institute of Nonproliferation and Control International Nuclear Security Academy, Daejeon (Korea, Republic of)

    2015-05-15

    All organizations involved in implementing physical protection should give due priority to the security culture, to its development and maintenance necessary to ensure its effective implementation in the entire organization. In this context, Korea Institute of Non-proliferation and Control(KINAC) confirms recognition about protection of people who work in nuclear field and developed questionnaire for utilizing fundamental data for nuclear security culture enhancement activity and conducted a survey. As a result, systematic education needs to employees. Choosing differentiated topic is required to consider employees because recognition level of age, position and division is different. And a variety of education technology as obligatory education such as filling the course time or the one-off thing has limitation. And taking complementary measures needs since there were many opinions that employees feel difficult to understand papers such as regulation and guidelines and so on related security. Finally, we hope to make fundament available to evaluate nuclear security culture recognition level based on the existing questionnaire would be changed to realistic and enhancement in recognition survey for future nuclear security culture.

  13. Flexible single molecule simulation of reaction-diffusion processes

    International Nuclear Information System (INIS)

    Hellander, Stefan; Loetstedt, Per

    2011-01-01

    An algorithm is developed for simulation of the motion and reactions of single molecules at a microscopic level. The molecules diffuse in a solvent and react with each other or a polymer and molecules can dissociate. Such simulations are of interest e.g. in molecular biology. The algorithm is similar to the Green's function reaction dynamics (GFRD) algorithm by van Zon and ten Wolde where longer time steps can be taken by computing the probability density functions (PDFs) and then sample from the distribution functions. Our computation of the PDFs is much less complicated than GFRD and more flexible. The solution of the partial differential equation for the PDF is split into two steps to simplify the calculations. The sampling is without splitting error in two of the coordinate directions for a pair of molecules and a molecule-polymer interaction and is approximate in the third direction. The PDF is obtained either from an analytical solution or a numerical discretization. The errors due to the operator splitting, the partitioning of the system, and the numerical approximations are analyzed. The method is applied to three different systems involving up to four reactions. Comparisons with other mesoscopic and macroscopic models show excellent agreement.

  14. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera

    Directory of Open Access Journals (Sweden)

    Kubanek Julia

    2009-09-01

    , even at synonymous positions, suggests that the repeats are kept nearly identical through a process of concerted evolution. Information-rich molecules like surface glycoproteins are well adapted for chemical communication and aquatic animals may have evolved signaling systems based on these compounds, whereas insects use cuticular hydrocarbons. Conclusion Owing to its critical role in mating, the mate recognition pheromone gene will be a useful molecular marker for exploring the mechanisms and rates of selection and the evolution of reproductive isolation and speciation using rotifers as a model system. The phylogenetic variation in the mate recognition pheromone gene can now be studied in conjunction with the large amount of ecological and population genetic data being gathered for the Brachionus plicatilis species complex to understand better the evolutionary drivers of cryptic speciation.

  15. Single-molecule mechanics of protein-labelled DNA handles

    Directory of Open Access Journals (Sweden)

    Vivek S. Jadhav

    2016-01-01

    Full Text Available DNA handles are often used as spacers and linkers in single-molecule experiments to isolate and tether RNAs, proteins, enzymes and ribozymes, amongst other biomolecules, between surface-modified beads for nanomechanical investigations. Custom DNA handles with varying lengths and chemical end-modifications are readily and reliably synthesized en masse, enabling force spectroscopic measurements with well-defined and long-lasting mechanical characteristics under physiological conditions over a large range of applied forces. Although these chemically tagged DNA handles are widely used, their further individual modification with protein receptors is less common and would allow for additional flexibility in grabbing biomolecules for mechanical measurements. In-depth information on reliable protocols for the synthesis of these DNA–protein hybrids and on their mechanical characteristics under varying physiological conditions are lacking in literature. Here, optical tweezers are used to investigate different protein-labelled DNA handles in a microfluidic environment under different physiological conditions. Digoxigenin (DIG-dsDNA-biotin handles of varying sizes (1000, 3034 and 4056 bp were conjugated with streptavidin or neutravidin proteins. The DIG-modified ends of these hybrids were bound to surface-modified polystyrene (anti-DIG beads. Using different physiological buffers, optical force measurements showed consistent mechanical characteristics with long dissociation times. These protein-modified DNA hybrids were also interconnected in situ with other tethered biotinylated DNA molecules. Electron-multiplying CCD (EMCCD imaging control experiments revealed that quantum dot–streptavidin conjugates at the end of DNA handles remain freely accessible. The experiments presented here demonstrate that handles produced with our protein–DNA labelling procedure are excellent candidates for grasping single molecules exposing tags suitable for molecular

  16. Radiotherapy- and chemotherapy-induced normal tissue damage. The role of cytokines and adhesion molecules

    International Nuclear Information System (INIS)

    Plevova, P.

    2002-01-01

    Background. Ionising radiation and cytostatic agents used in cancer therapy exert damaging effects on normal tissues and induce a complex response at the cellular and molecular levels. Cytokines and adhesion molecules are involved in this response. Methods. Published data on the given topic have been reviewed. Results and conclusions. Various cytokines and adhesion molecules, including tumor necrosis factor α, interleukins- 1,-2,-4, and -6, interferon γ, granulocyte macrophage- and macrophage- colony stimulating factors, transforming growth factor β, platelet-derived growth factor, insulin-like growth factor I, fibroblast and epidermal growth factors, platelet-activating factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E- and P-selectins are involved in the response of normal tissues to ionizing radiation- and chemotherapy- induced normal tissues damage and are co-responsible for some side effects of these treatment modalities, including fever, anorexia and fatigue, suppression of hematopoiesis, both acute and late local tissue response. (author)

  17. Gender differences in the recognition of emotional faces: are men less efficient?

    Directory of Open Access Journals (Sweden)

    Ana Ruiz-Ibáñez

    2017-06-01

    Full Text Available As research in recollection of stimuli with emotional valence indicates, emotions influence memory. Many studies in face and emotional facial expression recognition have focused on age (young and old people and gender-associated (men and women differences. Nevertheless, this kind of studies has produced contradictory results, because of that, it would be necessary to study gender involvement in depth. The main objective of our research consists of analyzing the differences in image recognition using faces with emotional facial expressions between two groups composed by university students aged 18-30. The first group is constituted by men and the second one by women. The results showed statistically significant differences in face corrected recognition (hit rate - false alarm rate: the women demonstrated a better recognition than the men. However, other analyzed variables as time or efficiency do not provide conclusive results. Furthermore, a significant negative correlation between the time used and the efficiency when doing the task was found in the male group. This information reinforces not only the hypothesis of gender difference in face recognition, in favor of women, but also these ones that suggest a different cognitive processing of facial stimuli in both sexes. Finally, we argue the necessity of a greater research related to variables as age or sociocultural level.

  18. The Legal Recognition of Sign Languages

    Science.gov (United States)

    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…

  19. Human activity recognition and prediction

    CERN Document Server

    2016-01-01

    This book provides a unique view of human activity recognition, especially fine-grained human activity structure learning, human-interaction recognition, RGB-D data based action recognition, temporal decomposition, and causality learning in unconstrained human activity videos. The techniques discussed give readers tools that provide a significant improvement over existing methodologies of video content understanding by taking advantage of activity recognition. It links multiple popular research fields in computer vision, machine learning, human-centered computing, human-computer interaction, image classification, and pattern recognition. In addition, the book includes several key chapters covering multiple emerging topics in the field. Contributed by top experts and practitioners, the chapters present key topics from different angles and blend both methodology and application, composing a solid overview of the human activity recognition techniques. .

  20. Single-molecule FRET unveils induced-fit mechanism for substrate selectivity in flap endonuclease 1

    KAUST Repository

    Rashid, Fahad

    2017-02-23

    Human flap endonuclease 1 (FEN1) and related structure-specific 5\\'nucleases precisely identify and incise aberrant DNA structures during replication, repair and recombination to avoid genomic instability. Yet, it is unclear how the 5\\'nuclease mechanisms of DNA distortion and protein ordering robustly mediate efficient and accurate substrate recognition and catalytic selectivity. Here, single-molecule sub-millisecond and millisecond analyses of FEN1 reveal a protein-DNA induced-fit mechanism that efficiently verifies substrate and suppresses off-target cleavage. FEN1 sculpts DNA with diffusion-limited kinetics to test DNA substrate. This DNA distortion mutually \\'locks\\' protein and DNA conformation and enables substrate verification with extreme precision. Strikingly, FEN1 never misses cleavage of its cognate substrate while blocking probable formation of catalytically competent interactions with noncognate substrates and fostering their pre-incision dissociation. These findings establish FEN1 has practically perfect precision and that separate control of induced-fit substrate recognition sets up the catalytic selectivity of the nuclease active site for genome stability.

  1. Chirality as a tool in nucleic acid recognition: principles and relevance in biotechnology and in medicinal chemistry.

    Science.gov (United States)

    Corradini, Roberto; Sforza, Stefano; Tedeschi, Tullia; Marchelli, Rosangela

    2007-05-05

    The understanding of the interaction of chiral species with DNA or RNA is very important for the development of new tools in biology and of new drugs. Several cases in which chirality is a crucial point in determining the DNA binding mode are reviewed and discussed, with the aim of illustrating how chirality can be considered as a tool for improving the understanding of mechanisms and the effectiveness of nucleic acid recognition. The review is divided into two parts: the former describes examples of chiral species interacting with DNA: intercalators, metal complexes, and groove binders; the latter part is dedicated to chirality in DNA analogs, with discussion of phosphate stereochemistry and chirality of ribose substitutes, in particular of peptide nucleic acids (PNAs) for which a number of works have been published recently dealing with the effect of chirality in DNA recognition. The discussion is intended to show how enantiomeric recognition originates at the molecular level, by exploiting the enormous progresses recently achieved in the field of structural characterization of complexes formed by nucleic acid with their ligands by crystallographic and spectroscopic methods. Examples of application of the DNA binding molecules described and the role of chirality in DNA recognition relevant for biotechnology or medicinal chemistry are reported. (c) 2007 Wiley-Liss, Inc.

  2. Face Processing and Facial Emotion Recognition in Adults with Down Syndrome

    Science.gov (United States)

    Barisnikov, Koviljka; Hippolyte, Loyse; Van der Linden, Martial

    2008-01-01

    Face processing and facial expression recognition was investigated in 17 adults with Down syndrome, and results were compared with those of a child control group matched for receptive vocabulary. On the tasks involving faces without emotional content, the adults with Down syndrome performed significantly worse than did the controls. However, their…

  3. Radar automatic target recognition (ATR) and non-cooperative target recognition (NCTR)

    CERN Document Server

    Blacknell, David

    2013-01-01

    The ability to detect and locate targets by day or night, over wide areas, regardless of weather conditions has long made radar a key sensor in many military and civil applications. However, the ability to automatically and reliably distinguish different targets represents a difficult challenge. Radar Automatic Target Recognition (ATR) and Non-Cooperative Target Recognition (NCTR) captures material presented in the NATO SET-172 lecture series to provide an overview of the state-of-the-art and continuing challenges of radar target recognition. Topics covered include the problem as applied to th

  4. Recognition and Toleration

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2010-01-01

    Recognition and toleration are ways of relating to the diversity characteristic of multicultural societies. The article concerns the possible meanings of toleration and recognition, and the conflict that is often claimed to exist between these two approaches to diversity. Different forms or inter...

  5. Remote control of therapeutic T cells through a small molecule-gated chimeric receptor.

    Science.gov (United States)

    Wu, Chia-Yung; Roybal, Kole T; Puchner, Elias M; Onuffer, James; Lim, Wendell A

    2015-10-16

    There is growing interest in using engineered cells as therapeutic agents. For example, synthetic chimeric antigen receptors (CARs) can redirect T cells to recognize and eliminate tumor cells expressing specific antigens. Despite promising clinical results, these engineered T cells can exhibit excessive activity that is difficult to control and can cause severe toxicity. We designed "ON-switch" CARs that enable small-molecule control over T cell therapeutic functions while still retaining antigen specificity. In these split receptors, antigen-binding and intracellular signaling components assemble only in the presence of a heterodimerizing small molecule. This titratable pharmacologic regulation could allow physicians to precisely control the timing, location, and dosage of T cell activity, thereby mitigating toxicity. This work illustrates the potential of combining cellular engineering with orthogonal chemical tools to yield safer therapeutic cells that tightly integrate cell-autonomous recognition and user control. Copyright © 2015, American Association for the Advancement of Science.

  6. Intelligent Facial Recognition Systems: Technology advancements for security applications

    Energy Technology Data Exchange (ETDEWEB)

    Beer, C.L.

    1993-07-01

    Insider problems such as theft and sabotage can occur within the security and surveillance realm of operations when unauthorized people obtain access to sensitive areas. A possible solution to these problems is a means to identify individuals (not just credentials or badges) in a given sensitive area and provide full time personnel accountability. One approach desirable at Department of Energy facilities for access control and/or personnel identification is an Intelligent Facial Recognition System (IFRS) that is non-invasive to personnel. Automatic facial recognition does not require the active participation of the enrolled subjects, unlike most other biological measurement (biometric) systems (e.g., fingerprint, hand geometry, or eye retinal scan systems). It is this feature that makes an IFRS attractive for applications other than access control such as emergency evacuation verification, screening, and personnel tracking. This paper discusses current technology that shows promising results for DOE and other security applications. A survey of research and development in facial recognition identified several companies and universities that were interested and/or involved in the area. A few advanced prototype systems were also identified. Sandia National Laboratories is currently evaluating facial recognition systems that are in the advanced prototype stage. The initial application for the evaluation is access control in a controlled environment with a constant background and with cooperative subjects. Further evaluations will be conducted in a less controlled environment, which may include a cluttered background and subjects that are not looking towards the camera. The outcome of the evaluations will help identify areas of facial recognition systems that need further development and will help to determine the effectiveness of the current systems for security applications.

  7. Integrated structural biology to unravel molecular mechanisms of protein-RNA recognition.

    Science.gov (United States)

    Schlundt, Andreas; Tants, Jan-Niklas; Sattler, Michael

    2017-04-15

    Recent advances in RNA sequencing technologies have greatly expanded our knowledge of the RNA landscape in cells, often with spatiotemporal resolution. These techniques identified many new (often non-coding) RNA molecules. Large-scale studies have also discovered novel RNA binding proteins (RBPs), which exhibit single or multiple RNA binding domains (RBDs) for recognition of specific sequence or structured motifs in RNA. Starting from these large-scale approaches it is crucial to unravel the molecular principles of protein-RNA recognition in ribonucleoprotein complexes (RNPs) to understand the underlying mechanisms of gene regulation. Structural biology and biophysical studies at highest possible resolution are key to elucidate molecular mechanisms of RNA recognition by RBPs and how conformational dynamics, weak interactions and cooperative binding contribute to the formation of specific, context-dependent RNPs. While large compact RNPs can be well studied by X-ray crystallography and cryo-EM, analysis of dynamics and weak interaction necessitates the use of solution methods to capture these properties. Here, we illustrate methods to study the structure and conformational dynamics of protein-RNA complexes in solution starting from the identification of interaction partners in a given RNP. Biophysical and biochemical techniques support the characterization of a protein-RNA complex and identify regions relevant in structural analysis. Nuclear magnetic resonance (NMR) is a powerful tool to gain information on folding, stability and dynamics of RNAs and characterize RNPs in solution. It provides crucial information that is complementary to the static pictures derived from other techniques. NMR can be readily combined with other solution techniques, such as small angle X-ray and/or neutron scattering (SAXS/SANS), electron paramagnetic resonance (EPR), and Förster resonance energy transfer (FRET), which provide information about overall shapes, internal domain

  8. Why the long face? The importance of vertical image structure for biological "barcodes" underlying face recognition.

    Science.gov (United States)

    Spence, Morgan L; Storrs, Katherine R; Arnold, Derek H

    2014-07-29

    Humans are experts at face recognition. The mechanisms underlying this complex capacity are not fully understood. Recently, it has been proposed that face recognition is supported by a coarse-scale analysis of visual information contained in horizontal bands of contrast distributed along the vertical image axis-a biological facial "barcode" (Dakin & Watt, 2009). A critical prediction of the facial barcode hypothesis is that the distribution of image contrast along the vertical axis will be more important for face recognition than image distributions along the horizontal axis. Using a novel paradigm involving dynamic image distortions, a series of experiments are presented examining famous face recognition impairments from selectively disrupting image distributions along the vertical or horizontal image axes. Results show that disrupting the image distribution along the vertical image axis is more disruptive for recognition than matched distortions along the horizontal axis. Consistent with the facial barcode hypothesis, these results suggest that human face recognition relies disproportionately on appropriately scaled distributions of image contrast along the vertical image axis. © 2014 ARVO.

  9. Molecular limit of a bulk semiconductor: size dependent optical spectroscopy study of CdSe cluster molecules

    Energy Technology Data Exchange (ETDEWEB)

    Soloviev, V.N.; Banin, U. [Hebrew Univ., Jerusalem (Israel). Dept. of Physical Chemistry; Eichhoefer, A. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Nanotechnologie; Fenske, D. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Nanotechnologie; Karlsruhe Univ. (T.H.) (Germany). Inst. fuer Anorganische Chemie

    2001-03-01

    Steady state and time-resolved photoluminescence measurements of a homologous series of CdSe cluster molecules were performed over a broad temperature range (T = 5-200 K). The absorption and low temperature PLE onset of the clusters shifts systematically to the blue in smaller clusters, manifesting the quantum confinement effect. The emission in all cluster molecules is observed only at low temperatures and is red-shifted significantly from the absorption onset. It is assigned to optically forbidden transitions involving surface states, as substantiated by the {mu}s range of lifetimes and by the involvement of low frequency vibrations of capping selenophenol ligands in the nonradiative relaxation of excited cluster molecules. (orig.)

  10. Super-recognition in development: A case study of an adolescent with extraordinary face recognition skills.

    Science.gov (United States)

    Bennetts, Rachel J; Mole, Joseph; Bate, Sarah

    2017-09-01

    Face recognition abilities vary widely. While face recognition deficits have been reported in children, it is unclear whether superior face recognition skills can be encountered during development. This paper presents O.B., a 14-year-old female with extraordinary face recognition skills: a "super-recognizer" (SR). O.B. demonstrated exceptional face-processing skills across multiple tasks, with a level of performance that is comparable to adult SRs. Her superior abilities appear to be specific to face identity: She showed an exaggerated face inversion effect and her superior abilities did not extend to object processing or non-identity aspects of face recognition. Finally, an eye-movement task demonstrated that O.B. spent more time than controls examining the nose - a pattern previously reported in adult SRs. O.B. is therefore particularly skilled at extracting and using identity-specific facial cues, indicating that face and object recognition are dissociable during development, and that super recognition can be detected in adolescence.

  11. Slp-76 is a critical determinant of NK cell-mediated recognition of missing-self targets

    OpenAIRE

    Lampe, Kristin; Endale, Mehari; Cashman, Siobhan; Fang, Hao; Mattner, Jochen; Hildeman, David; Hoebe, Kasper

    2015-01-01

    Absence of MHC class I expression is an important mechanism by which NK cells recognize a variety of target cells, yet the pathways underlying “missing-self” recognition, including the involvement of activating receptors, remain poorly understood. Using ENU mutagenesis in mice, we identified a germline mutant, designated Ace, with a marked defect in NK cell-mediated recognition and elimination of “missing-self” targets. The causative mutation was linked to chromosome 11 and identified as a mi...

  12. A motivational determinant of facial emotion recognition: regulatory focus affects recognition of emotions in faces.

    Science.gov (United States)

    Sassenrath, Claudia; Sassenberg, Kai; Ray, Devin G; Scheiter, Katharina; Jarodzka, Halszka

    2014-01-01

    Two studies examined an unexplored motivational determinant of facial emotion recognition: observer regulatory focus. It was predicted that a promotion focus would enhance facial emotion recognition relative to a prevention focus because the attentional strategies associated with promotion focus enhance performance on well-learned or innate tasks - such as facial emotion recognition. In Study 1, a promotion or a prevention focus was experimentally induced and better facial emotion recognition was observed in a promotion focus compared to a prevention focus. In Study 2, individual differences in chronic regulatory focus were assessed and attention allocation was measured using eye tracking during the facial emotion recognition task. Results indicated that the positive relation between a promotion focus and facial emotion recognition is mediated by shorter fixation duration on the face which reflects a pattern of attention allocation matched to the eager strategy in a promotion focus (i.e., striving to make hits). A prevention focus did not have an impact neither on perceptual processing nor on facial emotion recognition. Taken together, these findings demonstrate important mechanisms and consequences of observer motivational orientation for facial emotion recognition.

  13. Presentation of lipid antigens to T cells.

    Science.gov (United States)

    Mori, Lucia; De Libero, Gennaro

    2008-04-15

    T cells specific for lipid antigens participate in regulation of the immune response during infections, tumor immunosurveillance, allergy and autoimmune diseases. T cells recognize lipid antigens as complexes formed with CD1 antigen-presenting molecules, thus resembling recognition of MHC-peptide complexes. The biophysical properties of lipids impose unique mechanisms for their delivery, internalization into antigen-presenting cells, membrane trafficking, processing, and loading of CD1 molecules. Each of these steps is controlled at molecular and celular levels and determines lipid immunogenicity. Lipid antigens may derive from microbes and from the cellular metabolism, thus allowing the immune system to survey a large repertoire of immunogenic molecules. Recognition of lipid antigens facilitates the detection of infectious agents and the initiation of responses involved in immunoregulation and autoimmunity. This review focuses on the presentation mechanisms and specific recognition of self and bacterial lipid antigens and discusses the important open issues.

  14. Pattern recognition & machine learning

    CERN Document Server

    Anzai, Y

    1992-01-01

    This is the first text to provide a unified and self-contained introduction to visual pattern recognition and machine learning. It is useful as a general introduction to artifical intelligence and knowledge engineering, and no previous knowledge of pattern recognition or machine learning is necessary. Basic for various pattern recognition and machine learning methods. Translated from Japanese, the book also features chapter exercises, keywords, and summaries.

  15. A REVIEW: OPTICAL CHARACTER RECOGNITION

    OpenAIRE

    Swati Tomar*1 & Amit Kishore2

    2018-01-01

    This paper presents detailed review in the field of Optical Character Recognition. Various techniques are determine that have been proposed to realize the center of character recognition in an optical character recognition system. Even though, sufficient studies and papers are describes the techniques for converting textual content from a paper document into machine readable form. Optical character recognition is a process where the computer understands automatically the image of handwritten ...

  16. Can Massive but Passive Exposure to Faces Contribute to Face Recognition Abilities?

    Science.gov (United States)

    Yovel, Galit; Halsband, Keren; Pelleg, Michel; Farkash, Naomi; Gal, Bracha; Goshen-Gottstein, Yonatan

    2012-01-01

    Recent studies have suggested that individuation of other-race faces is more crucial for enhancing recognition performance than exposure that involves categorization of these faces to an identity-irrelevant criterion. These findings were primarily based on laboratory training protocols that dissociated exposure and individuation by using…

  17. The synthesis and host-guest applications of synthetic receptor molecules

    Science.gov (United States)

    Osner, Zachary R.

    2011-12-01

    Host-guest chemistry involves the complimentary binding between two molecules. Host molecules have been synthesized to bind negative, positive, and neutral molecules such as proteins and enzymes, and have been used as optical sensors, electrochemical sensors, supramolecular catalysts, and in the pharmaceutical industry as anti-cancer agents.1 The field of nanoscience has exploited guest-host interactions to create optical sensors with colloidal gold and Dip-Pen nanolithography technologies. Gold nanoparticles, have been functionalized with DNA, and have been developed as a selective colorimetric detection system, that upon binding turns the solution from a red to blue in color.2 Cyclotriveratrylene (CTV) 1 is a common supramolecular scaffold that has been previously employed in guest-host chemistry, and the construction of CTV involves the cyclic trimerization of veratryl alcohol via the veratryl cation.3 Due to the rigid bowl shaped structure of CTV, CTV has been shown to act as a host molecule for fullerene-C60.4 Lectin binding receptor proteins are a specific class of proteins found in bacteria, viruses, plants, and animals that can bind to complimentary carbohydrates. It is these lectins that are believed to be responsible for cell-cell interactions and the formation of biofilms in pathenogenic bacteria.5 P. aeruginosa is a pathenogenic bacterium, shown to have a high resistance to many antibiotics, which can form biofilms in human lung tissue, causing respiratory tract infections in patients with compromised immune systems. 5 I will exploit guest-host interactions to create synthetic supramolecular and carbohydrate receptor molecules to that will be of use as biological sensing devices via self-assembled monolayers on solid surfaces and nanoparticle technologies. *Please refer to dissertation for references/footnotes.

  18. Heterogeneous sharpness for cross-spectral face recognition

    Science.gov (United States)

    Cao, Zhicheng; Schmid, Natalia A.

    2017-05-01

    Matching images acquired in different electromagnetic bands remains a challenging problem. An example of this type of comparison is matching active or passive infrared (IR) against a gallery of visible face images, known as cross-spectral face recognition. Among many unsolved issues is the one of quality disparity of the heterogeneous images. Images acquired in different spectral bands are of unequal image quality due to distinct imaging mechanism, standoff distances, or imaging environment, etc. To reduce the effect of quality disparity on the recognition performance, one can manipulate images to either improve the quality of poor-quality images or to degrade the high-quality images to the level of the quality of their heterogeneous counterparts. To estimate the level of discrepancy in quality of two heterogeneous images a quality metric such as image sharpness is needed. It provides a guidance in how much quality improvement or degradation is appropriate. In this work we consider sharpness as a relative measure of heterogeneous image quality. We propose a generalized definition of sharpness by first achieving image quality parity and then finding and building a relationship between the image quality of two heterogeneous images. Therefore, the new sharpness metric is named heterogeneous sharpness. Image quality parity is achieved by experimentally finding the optimal cross-spectral face recognition performance where quality of the heterogeneous images is varied using a Gaussian smoothing function with different standard deviation. This relationship is established using two models; one of them involves a regression model and the other involves a neural network. To train, test and validate the model, we use composite operators developed in our lab to extract features from heterogeneous face images and use the sharpness metric to evaluate the face image quality within each band. Images from three different spectral bands visible light, near infrared, and short

  19. Ion and electron swarm studies of relevance to plasma processing: positive ion-molecule and electron-molecule studies of SF6 and derivatives

    International Nuclear Information System (INIS)

    Atterbury, C.; Kennedy, R.A.; Critchley, A.D.J.; Mayhew, C.A.

    2002-01-01

    Many sequential and parallel chemical reactions involving charged species occur in a plasma. Data needed to model plasma's chemical and physical environment includes cross-section, rate coefficients, and product ion distribution of electron-molecule and ion-molecule processes. Such reactions are studied by our group away from the complexity of the plasma environment, with experimental techniques that allow us to concentrate on a single process, where usually only one or two species are involved. A molecule commonly used in plasma etching applications is SF 6 1,2 . We have performed a series of positive ion-molecule and electron attachment studies on SF 6 and related molecules, including SeF 6 , TeF 6 (i.e. XF 6 molecules), SF 5 CF 3 and SF 5 Cl (i.e. SF 5 X molecules) 3- (. The studies of ion reactions with and electron attachment to SF 6 and physically similar molecules are of value when seeking to understand the ion and electron chemistry occurring in SF 6 containing plasma. The result of these studies are presented in this poster. Ion-molecule reactions. Rate coefficients and ion product branching ratios have been determined with the Selected Ion Flow Tube (SIFT) at room temperature (300 K) for reactions of SF 5 X with the following twenty-two cations; Ne + , F + , Ar + , N 2 + , N + , CO + , CO 2 + , O + , N 2 O + , O 2 + , SF 4 + , CF 2 + , SF + , SF 2 + , NO 2 + , SF 5 + , NO + , CF + , CF 3 + , SF 3 + , and H 3 O + (listed in order of decreasing recombination energy). SF 2 + , NO 2 + , NO + , SF 3 + , and H 3 O + are found to be unreacted with both SF 5 CF 3 and SF 5 Cl. The majority of the other reactions proceed with rate coefficients that are close to the capture value. Those found to occur at rates significantly less than the capture mechanism value re the reactions of O 2 + , SF + , SF 5 + , and CF 3 + with SF 5 CF 3 , and SF 4 + and SF 5 + with SF 5 Cl. Several distinction processes are observed among the large number of reactions studied, including

  20. Challenging ocular image recognition

    Science.gov (United States)

    Pauca, V. Paúl; Forkin, Michael; Xu, Xiao; Plemmons, Robert; Ross, Arun A.

    2011-06-01

    Ocular recognition is a new area of biometric investigation targeted at overcoming the limitations of iris recognition performance in the presence of non-ideal data. There are several advantages for increasing the area beyond the iris, yet there are also key issues that must be addressed such as size of the ocular region, factors affecting performance, and appropriate corpora to study these factors in isolation. In this paper, we explore and identify some of these issues with the goal of better defining parameters for ocular recognition. An empirical study is performed where iris recognition methods are contrasted with texture and point operators on existing iris and face datasets. The experimental results show a dramatic recognition performance gain when additional features are considered in the presence of poor quality iris data, offering strong evidence for extending interest beyond the iris. The experiments also highlight the need for the direct collection of additional ocular imagery.

  1. Automatic Speech Recognition from Neural Signals: A Focused Review

    Directory of Open Access Journals (Sweden)

    Christian Herff

    2016-09-01

    Full Text Available Speech interfaces have become widely accepted and are nowadays integrated in various real-life applications and devices. They have become a part of our daily life. However, speech interfaces presume the ability to produce intelligible speech, which might be impossible due to either loud environments, bothering bystanders or incapabilities to produce speech (i.e.~patients suffering from locked-in syndrome. For these reasons it would be highly desirable to not speak but to simply envision oneself to say words or sentences. Interfaces based on imagined speech would enable fast and natural communication without the need for audible speech and would give a voice to otherwise mute people.This focused review analyzes the potential of different brain imaging techniques to recognize speech from neural signals by applying Automatic Speech Recognition technology. We argue that modalities based on metabolic processes, such as functional Near Infrared Spectroscopy and functional Magnetic Resonance Imaging, are less suited for Automatic Speech Recognition from neural signals due to low temporal resolution but are very useful for the investigation of the underlying neural mechanisms involved in speech processes. In contrast, electrophysiologic activity is fast enough to capture speech processes and is therefor better suited for ASR. Our experimental results indicate the potential of these signals for speech recognition from neural data with a focus on invasively measured brain activity (electrocorticography. As a first example of Automatic Speech Recognition techniques used from neural signals, we discuss the emph{Brain-to-text} system.

  2. Natural Killer cell recognition of melanoma: new clues for a more effective immunotherapy

    Directory of Open Access Journals (Sweden)

    Raquel eTarazona

    2016-01-01

    Full Text Available Natural killer cells participate in the early immune response against melanoma and also contribute to the development of an adequate adaptive immune response by their crosstalk with dendritic cells and cytokine secretion. Melanoma resistance to conventional therapies together with its high immunogenicity justifies the development of novel therapies aimed to stimulate effective immune responses against melanoma. However, melanoma cells frequently escape to CD8 T cell recognition by the down-regulation of major histocompatibility complex class I molecules. In this scenario, Natural killer cells emerge as potential candidates for melanoma immunotherapy due to their capacity to recognize and destroy melanoma cells expressing low levels of major histocompatibility complex class I molecules. In addition, the possibility to combine immune checkpoint blockade with other NK cell potentiating strategies (e.g. cytokine induction of activating receptors has opened new perspectives in the potential use of adoptive NK cell-based immunotherapy in melanoma.

  3. Selecting Molecular Recognition. What Can Existing Aptamers Tell Us about Their Inherent Recognition Capabilities and Modes of Interaction?

    Directory of Open Access Journals (Sweden)

    Ralf Landgraf

    2012-05-01

    Full Text Available The use of nucleic acid derived aptamers has rapidly expanded since the introduction of SELEX in 1990. Nucleic acid aptamers have demonstrated their ability to target a broad range of molecules in ways that rival antibodies, but advances have been very uneven for different biochemical classes of targets, and clinical applications have been slow to emerge. What sets different aptamers apart from each other and from rivaling molecular recognition platforms, specifically proteins? What advantages do aptamers as a reagent class offer, and how do the chemical properties and selection procedures of aptamers influence their function? Do the building blocks of nucleic acid aptamers dictate inherent limitations in the nature of molecular targets, and do existing aptamers give us insight in how these challenges might be overcome? This review is written as an introduction for potential endusers of aptamer technology who are evaluating the advantages of aptamers as a versatile, affordable, yet highly expandable platform to target a broad range of biological processes or interactions.

  4. Photoelectron angular distributions from strong-field ionization of oriented molecules

    DEFF Research Database (Denmark)

    Holmegaard, Lotte; Hansen, Jonas Lerche; Kalhøj, Line

    2010-01-01

    The combination of ultrafast light sources with detection of molecular-frame photoelectron angular distributions (MFPADs) is setting new standards for detailed interrogation of molecular dynamics. However, until recently measurement of MFPADs relied on determining the molecular orientation after...... ionization, which is limited to species and processes where ionization leads to fragmentation. An alternative is to fix the molecular frame before ionization. The only demonstrations of such spatial orientation involved aligned small linear nonpolar molecules. Here we extend these techniques to the general...... class of polar molecules. Carbonylsulphide and benzonitrile molecules, fixed in space by combined laser and electrostatic fields, are ionized with intense, circularly polarized 30-fs laser pulses. For carbonylsulphide and benzonitrile oriented in one dimension, the MFPADs exhibit pronounced anisotropies...

  5. Insight to structural subsite recognition in plant thiol protease-inhibitor complexes : Understanding the basis of differential inhibition and the role of water

    Directory of Open Access Journals (Sweden)

    Mukhopadhayay Bishnu P

    2001-09-01

    Full Text Available Abstract Background This work represents an extensive MD simulation / water-dynamics studies on a series of complexes of inhibitors (leupeptin, E-64, E-64-C, ZPACK and plant cysteine proteases (actinidin, caricain, chymopapain, calotropin DI of papain family to understand the various interactions, water binding mode, factors influencing it and the structural basis of differential inhibition. Results The tertiary structure of the enzyme-inhibitor complexes were built by visual interactive modeling and energy minimization followed by dynamic simulation of 120 ps in water environment. DASA study with and without the inhibitor revealed the potential subsite residues involved in inhibition. Though the interaction involving main chain atoms are similar, critical inspection of the complexes reveal significant differences in the side chain interactions in S2-P2 and S3-P3 pairs due to sequence differences in the equivalent positions of respective subsites leading to differential inhibition. Conclusion The key finding of the study is a conserved site of a water molecule near oxyanion hole of the enzyme active site, which is found in all the modeled complexes and in most crystal structures of papain family either native or complexed. Conserved water molecules at the ligand binding sites of these homologous proteins suggest the structural importance of the water, which changes the conventional definition of chemical geometry of inhibitor binding domain, its shape and complimentarity. The water mediated recognition of inhibitor to enzyme subsites (Pn...H2O....Sn of leupeptin acetyl oxygen to caricain, chymopapain and calotropinDI is an additional information and offer valuable insight to potent inhibitor design.

  6. Excited Atoms and Molecules in High Pressure Gas Discharges

    International Nuclear Information System (INIS)

    Vuskovic, L.; Popovic, S.

    2003-01-01

    Various types of high-pressure non-thermal discharges are increasingly drawing attention in view of many interesting applications. These, partially ionized media in non-equilibrium state, tend to generate complex effects that are difficult to interpret without a detailed knowledge of elementary processes involved. Electronically excited molecules and atoms may play an important role as intermediate states in a wide range of atomic and molecular processes, many of which are important in high-pressure discharges. They can serve also as reservoirs of energy or as sources of high energy electrons either through the energy pooling or through superelastic collisions. By presenting the analysis of current situation on the processes involving excited atoms and molecules of interest for high-pressure gas discharges, we will attempt to draw attention on the insufficiency of available data. In the same time we will show how to circumvent this situation and still be able to develop accurate models and interpretations of the observed phenomena

  7. Heterocyclic Dications as a New Class of Telomeric G-Quadruplex Targeting Agents

    Science.gov (United States)

    Nanjunda, Rupesh; Musetti, Caterina; Kumar, Arvind; Ismail, Mohamed A.; Farahat, Abdelbasset A.; Wang, Siming; Sissi, Claudia; Palumbo, Manlio; Boykin, David W.; Wilson, W. David

    2013-01-01

    Small molecules that can induce and stabilize G-quadruplex DNA structures represent a novel approach for anti-cancer and anti-parasitic therapy and extensive efforts have been directed towards discovering lead compounds that are capable of stabilizing quadruplexes. The purpose of this study is to explore conformational modifications in a series of heterocyclic dications to discover structural motifs that can selectively bind and stabilize specific G-quadruplexes, such as those present in the human telomere. The G-quadruplex has various potential recognition sites for small molecules; however, the primary interaction site of most of these ligands is the terminal tetrads. Similar to duplex-DNA groove recognition, quadruplex groove recognition by small molecules offers the potential for enhanced selectivity that can be developed into a viable therapeutic strategy. The compounds investigated were selected based on preliminary studies with DB832, a bifuryl-phenyl diamidine with a unique telomere interaction. This compound provides a paradigm that can help in understanding the optimum compound-DNA interactions that lead to quadruplex groove recognition. DNA recognition by the DB832 derivatives was investigated by biophysical experiments such as thermal melting, circular dichroism, mass spectrometry and NMR. Biological studies were also performed to complement the biophysical data. The results suggest a complex binding mechanism which involves the recognition of grooves for some ligands as well as stacking at the terminal tetrads of the human telomeric G-quadruplex for most of the ligands. These molecules represent an excellent starting point for further SAR analysis for diverse modes of quadruplex recognition and subsequent structure optimization for drug development. PMID:22380518

  8. Genetic specificity of face recognition.

    Science.gov (United States)

    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. Face Detection and Recognition

    National Research Council Canada - National Science Library

    Jain, Anil K

    2004-01-01

    This report describes research efforts towards developing algorithms for a robust face recognition system to overcome many of the limitations found in existing two-dimensional facial recognition systems...

  10. Forensic Face Recognition: A Survey

    NARCIS (Netherlands)

    Ali, Tauseef; Spreeuwers, Lieuwe Jan; Veldhuis, Raymond N.J.; Quaglia, Adamo; Epifano, Calogera M.

    2012-01-01

    The improvements of automatic face recognition during the last 2 decades have disclosed new applications like border control and camera surveillance. A new application field is forensic face recognition. Traditionally, face recognition by human experts has been used in forensics, but now there is a

  11. Brain dynamics of upstream perceptual processes leading to visual object recognition: a high density ERP topographic mapping study.

    Science.gov (United States)

    Schettino, Antonio; Loeys, Tom; Delplanque, Sylvain; Pourtois, Gilles

    2011-04-01

    Recent studies suggest that visual object recognition is a proactive process through which perceptual evidence accumulates over time before a decision can be made about the object. However, the exact electrophysiological correlates and time-course of this complex process remain unclear. In addition, the potential influence of emotion on this process has not been investigated yet. We recorded high density EEG in healthy adult participants performing a novel perceptual recognition task. For each trial, an initial blurred visual scene was first shown, before the actual content of the stimulus was gradually revealed by progressively adding diagnostic high spatial frequency information. Participants were asked to stop this stimulus sequence as soon as they could correctly perform an animacy judgment task. Behavioral results showed that participants reliably gathered perceptual evidence before recognition. Furthermore, prolonged exploration times were observed for pleasant, relative to either neutral or unpleasant scenes. ERP results showed distinct effects starting at 280 ms post-stimulus onset in distant brain regions during stimulus processing, mainly characterized by: (i) a monotonic accumulation of evidence, involving regions of the posterior cingulate cortex/parahippocampal gyrus, and (ii) true categorical recognition effects in medial frontal regions, including the dorsal anterior cingulate cortex. These findings provide evidence for the early involvement, following stimulus onset, of non-overlapping brain networks during proactive processes eventually leading to visual object recognition. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Voice Recognition in Face-Blind Patients

    Science.gov (United States)

    Liu, Ran R.; Pancaroglu, Raika; Hills, Charlotte S.; Duchaine, Brad; Barton, Jason J. S.

    2016-01-01

    Right or bilateral anterior temporal damage can impair face recognition, but whether this is an associative variant of prosopagnosia or part of a multimodal disorder of person recognition is an unsettled question, with implications for cognitive and neuroanatomic models of person recognition. We assessed voice perception and short-term recognition of recently heard voices in 10 subjects with impaired face recognition acquired after cerebral lesions. All 4 subjects with apperceptive prosopagnosia due to lesions limited to fusiform cortex had intact voice discrimination and recognition. One subject with bilateral fusiform and anterior temporal lesions had a combined apperceptive prosopagnosia and apperceptive phonagnosia, the first such described case. Deficits indicating a multimodal syndrome of person recognition were found only in 2 subjects with bilateral anterior temporal lesions. All 3 subjects with right anterior temporal lesions had normal voice perception and recognition, 2 of whom performed normally on perceptual discrimination of faces. This confirms that such lesions can cause a modality-specific associative prosopagnosia. PMID:25349193

  13. Synthesis of Common Arabic Handwritings to Aid Optical Character Recognition Research

    Directory of Open Access Journals (Sweden)

    Laslo Dinges

    2016-03-01

    Full Text Available Document analysis tasks such as pattern recognition, word spotting or segmentation, require comprehensive databases for training and validation. Not only variations in writing style but also the used list of words is of importance in the case that training samples should reflect the input of a specific area of application. However, generation of training samples is expensive in the sense of manpower and time, particularly if complete text pages including complex ground truth are required. This is why there is a lack of such databases, especially for Arabic, the second most popular language. However, Arabic handwriting recognition involves different preprocessing, segmentation and recognition methods. Each requires particular ground truth or samples to enable optimal training and validation, which are often not covered by the currently available databases. To overcome this issue, we propose a system that synthesizes Arabic handwritten words and text pages and generates corresponding detailed ground truth. We use these syntheses to validate a new, segmentation based system that recognizes handwritten Arabic words. We found that a modification of an Active Shape Model based character classifiers—that we proposed earlier—improves the word recognition accuracy. Further improvements are achieved, by using a vocabulary of the 50,000 most common Arabic words for error correction.

  14. Synthesis of Common Arabic Handwritings to Aid Optical Character Recognition Research.

    Science.gov (United States)

    Dinges, Laslo; Al-Hamadi, Ayoub; Elzobi, Moftah; El-Etriby, Sherif

    2016-03-11

    Document analysis tasks such as pattern recognition, word spotting or segmentation, require comprehensive databases for training and validation. Not only variations in writing style but also the used list of words is of importance in the case that training samples should reflect the input of a specific area of application. However, generation of training samples is expensive in the sense of manpower and time, particularly if complete text pages including complex ground truth are required. This is why there is a lack of such databases, especially for Arabic, the second most popular language. However, Arabic handwriting recognition involves different preprocessing, segmentation and recognition methods. Each requires particular ground truth or samples to enable optimal training and validation, which are often not covered by the currently available databases. To overcome this issue, we propose a system that synthesizes Arabic handwritten words and text pages and generates corresponding detailed ground truth. We use these syntheses to validate a new, segmentation based system that recognizes handwritten Arabic words. We found that a modification of an Active Shape Model based character classifiers-that we proposed earlier-improves the word recognition accuracy. Further improvements are achieved, by using a vocabulary of the 50,000 most common Arabic words for error correction.

  15. Brain correlates of musical and facial emotion recognition: evidence from the dementias.

    Science.gov (United States)

    Hsieh, S; Hornberger, M; Piguet, O; Hodges, J R

    2012-07-01

    The recognition of facial expressions of emotion is impaired in semantic dementia (SD) and is associated with right-sided brain atrophy in areas known to be involved in emotion processing, notably the amygdala. Whether patients with SD also experience difficulty recognizing emotions conveyed by other media, such as music, is unclear. Prior studies have used excerpts of known music from classical or film repertoire but not unfamiliar melodies designed to convey distinct emotions. Patients with SD (n = 11), Alzheimer's disease (n = 12) and healthy control participants (n = 20) underwent tests of emotion recognition in two modalities: unfamiliar musical tunes and unknown faces as well as volumetric MRI. Patients with SD were most impaired with the recognition of facial and musical emotions, particularly for negative emotions. Voxel-based morphometry showed that the labelling of emotions, regardless of modality, correlated with the degree of atrophy in the right temporal pole, amygdala and insula. The recognition of musical (but not facial) emotions was also associated with atrophy of the left anterior and inferior temporal lobe, which overlapped with regions correlating with standardized measures of verbal semantic memory. These findings highlight the common neural substrates supporting the processing of emotions by facial and musical stimuli but also indicate that the recognition of emotions from music draws upon brain regions that are associated with semantics in language. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Specificity and multiplicity in the recognition of individuals: implications for the evolution of social behaviour.

    Science.gov (United States)

    Wiley, R H

    2013-02-01

    Recognition of conspecifics occurs when individuals classify sets of conspecifics based on sensory input from them and associate these sets with different responses. Classification of conspecifics can vary in specificity (the number of individuals included in a set) and multiplicity (the number of sets differentiated). In other words, the information transmitted varies in complexity. Although recognition of conspecifics has been reported in a wide variety of organisms, few reports have addressed the specificity or multiplicity of this capability. This review discusses examples of these patterns, the mechanisms that can produce them, and the evolution of these mechanisms. Individual recognition is one end of a spectrum of specificity, and binary classification of conspecifics is one end of a spectrum of multiplicity. In some cases, recognition requires no more than simple forms of learning, such as habituation, yet results in individually specific recognition. In other cases, recognition of individuals involves complex associations of multiple cues with multiple previous experiences in particular contexts. Complex mechanisms for recognition are expected to evolve only when simpler mechanisms do not provide sufficient specificity and multiplicity to obtain the available advantages. In particular, the evolution of cooperation and deception is always promoted by specificity and multiplicity in recognition. Nevertheless, there is only one demonstration that recognition of specific individuals contributes to cooperation in animals other than primates. Human capacities for individual recognition probably have a central role in the evolution of complex forms of human cooperation and deception. Although relatively little studied, this capability probably rivals cognitive abilities for language. © 2012 The Author. Biological Reviews © 2012 Cambridge Philosophical Society.

  17. Invariant Face recognition Using Infrared Images

    International Nuclear Information System (INIS)

    Zahran, E.G.

    2012-01-01

    Over the past few decades, face recognition has become a rapidly growing research topic due to the increasing demands in many applications of our daily life such as airport surveillance, personal identification in law enforcement, surveillance systems, information safety, securing financial transactions, and computer security. The objective of this thesis is to develop a face recognition system capable of recognizing persons with a high recognition capability, low processing time, and under different illumination conditions, and different facial expressions. The thesis presents a study for the performance of the face recognition system using two techniques; the Principal Component Analysis (PCA), and the Zernike Moments (ZM). The performance of the recognition system is evaluated according to several aspects including the recognition rate, and the processing time. Face recognition systems that use visual images are sensitive to variations in the lighting conditions and facial expressions. The performance of these systems may be degraded under poor illumination conditions or for subjects of various skin colors. Several solutions have been proposed to overcome these limitations. One of these solutions is to work in the Infrared (IR) spectrum. IR images have been suggested as an alternative source of information for detection and recognition of faces, when there is little or no control over lighting conditions. This arises from the fact that these images are formed due to thermal emissions from skin, which is an intrinsic property because these emissions depend on the distribution of blood vessels under the skin. On the other hand IR face recognition systems still have limitations with temperature variations and recognition of persons wearing eye glasses. In this thesis we will fuse IR images with visible images to enhance the performance of face recognition systems. Images are fused using the wavelet transform. Simulation results show that the fusion of visible and

  18. Development of visuo-haptic transfer for object recognition in typical preschool and school-aged children.

    Science.gov (United States)

    Purpura, Giulia; Cioni, Giovanni; Tinelli, Francesca

    2018-07-01

    Object recognition is a long and complex adaptive process and its full maturation requires combination of many different sensory experiences as well as cognitive abilities to manipulate previous experiences in order to develop new percepts and subsequently to learn from the environment. It is well recognized that the transfer of visual and haptic information facilitates object recognition in adults, but less is known about development of this ability. In this study, we explored the developmental course of object recognition capacity in children using unimodal visual information, unimodal haptic information, and visuo-haptic information transfer in children from 4 years to 10 years and 11 months of age. Participants were tested through a clinical protocol, involving visual exploration of black-and-white photographs of common objects, haptic exploration of real objects, and visuo-haptic transfer of these two types of information. Results show an age-dependent development of object recognition abilities for visual, haptic, and visuo-haptic modalities. A significant effect of time on development of unimodal and crossmodal recognition skills was found. Moreover, our data suggest that multisensory processes for common object recognition are active at 4 years of age. They facilitate recognition of common objects, and, although not fully mature, are significant in adaptive behavior from the first years of age. The study of typical development of visuo-haptic processes in childhood is a starting point for future studies regarding object recognition in impaired populations.

  19. End-Stop Exemplar Based Recognition

    DEFF Research Database (Denmark)

    Olsen, Søren I.

    2003-01-01

    An approach to exemplar based recognition of visual shapes is presented. The shape information is described by attributed interest points (keys) detected by an end-stop operator. The attributes describe the statistics of lines and edges local to the interest point, the position of neighboring int...... interest points, and (in the training phase) a list of recognition names. Recognition is made by a simple voting procedure. Preliminary experiments indicate that the recognition is robust to noise, small deformations, background clutter and partial occlusion....

  20. Speech Recognition on Mobile Devices

    DEFF Research Database (Denmark)

    Tan, Zheng-Hua; Lindberg, Børge

    2010-01-01

    in the mobile context covering motivations, challenges, fundamental techniques and applications. Three ASR architectures are introduced: embedded speech recognition, distributed speech recognition and network speech recognition. Their pros and cons and implementation issues are discussed. Applications within......The enthusiasm of deploying automatic speech recognition (ASR) on mobile devices is driven both by remarkable advances in ASR technology and by the demand for efficient user interfaces on such devices as mobile phones and personal digital assistants (PDAs). This chapter presents an overview of ASR...

  1. Markov Models for Handwriting Recognition

    CERN Document Server

    Plotz, Thomas

    2011-01-01

    Since their first inception, automatic reading systems have evolved substantially, yet the recognition of handwriting remains an open research problem due to its substantial variation in appearance. With the introduction of Markovian models to the field, a promising modeling and recognition paradigm was established for automatic handwriting recognition. However, no standard procedures for building Markov model-based recognizers have yet been established. This text provides a comprehensive overview of the application of Markov models in the field of handwriting recognition, covering both hidden

  2. Pedestrian dead reckoning employing simultaneous activity recognition cues

    International Nuclear Information System (INIS)

    Altun, Kerem; Barshan, Billur

    2012-01-01

    We consider the human localization problem using body-worn inertial/magnetic sensor units. Inertial sensors are characterized by a drift error caused by the integration of their rate output to obtain position information. Because of this drift, the position and orientation data obtained from inertial sensors are reliable over only short periods of time. Therefore, position updates from externally referenced sensors are essential. However, if the map of the environment is known, the activity context of the user can provide information about his position. In particular, the switches in the activity context correspond to discrete locations on the map. By performing localization simultaneously with activity recognition, we detect the activity context switches and use the corresponding position information as position updates in a localization filter. The localization filter also involves a smoother that combines the two estimates obtained by running the zero-velocity update algorithm both forward and backward in time. We performed experiments with eight subjects in indoor and outdoor environments involving walking, turning and standing activities. Using a spatial error criterion, we show that the position errors can be decreased by about 85% on the average. We also present the results of two 3D experiments performed in realistic indoor environments and demonstrate that it is possible to achieve over 90% error reduction in position by performing localization simultaneously with activity recognition. (paper)

  3. Arabic sign language recognition based on HOG descriptor

    Science.gov (United States)

    Ben Jmaa, Ahmed; Mahdi, Walid; Ben Jemaa, Yousra; Ben Hamadou, Abdelmajid

    2017-02-01

    We present in this paper a new approach for Arabic sign language (ArSL) alphabet recognition using hand gesture analysis. This analysis consists in extracting a histogram of oriented gradient (HOG) features from a hand image and then using them to generate an SVM Models. Which will be used to recognize the ArSL alphabet in real-time from hand gesture using a Microsoft Kinect camera. Our approach involves three steps: (i) Hand detection and localization using a Microsoft Kinect camera, (ii) hand segmentation and (iii) feature extraction using Arabic alphabet recognition. One each input image first obtained by using a depth sensor, we apply our method based on hand anatomy to segment hand and eliminate all the errors pixels. This approach is invariant to scale, to rotation and to translation of the hand. Some experimental results show the effectiveness of our new approach. Experiment revealed that the proposed ArSL system is able to recognize the ArSL with an accuracy of 90.12%.

  4. Examining ERP correlates of recognition memory: Evidence of accurate source recognition without recollection

    Science.gov (United States)

    Addante, Richard, J.; Ranganath, Charan; Yonelinas, Andrew, P.

    2012-01-01

    Recollection is typically associated with high recognition confidence and accurate source memory. However, subjects sometimes make accurate source memory judgments even for items that are not confidently recognized, and it is not known whether these responses are based on recollection or some other memory process. In the current study, we measured event related potentials (ERPs) while subjects made item and source memory confidence judgments in order to determine whether recollection supported accurate source recognition responses for items that were not confidently recognized. In line with previous studies, we found that recognition memory was associated with two ERP effects: an early on-setting FN400 effect, and a later parietal old-new effect [Late Positive Component (LPC)], which have been associated with familiarity and recollection, respectively. The FN400 increased gradually with item recognition confidence, whereas the LPC was only observed for highly confident recognition responses. The LPC was also related to source accuracy, but only for items that had received a high confidence item recognition response; accurate source judgments to items that were less confidently recognized did not exhibit the typical ERP correlate of recollection or familiarity, but rather showed a late, broadly distributed negative ERP difference. The results indicate that accurate source judgments of episodic context can occur even when recollection fails. PMID:22548808

  5. Evaluating music emotion recognition:Lessons from music genre recognition?

    OpenAIRE

    Sturm, Bob L.

    2013-01-01

    A fundamental problem with nearly all work in music genre recognition (MGR)is that evaluation lacks validity with respect to the principal goals of MGR. This problem also occurs in the evaluation of music emotion recognition (MER). Standard approaches to evaluation, though easy to implement, do not reliably differentiate between recognizing genre or emotion from music, or by virtue of confounding factors in signals (e.g., equalization). We demonstrate such problems for evaluating an MER syste...

  6. Evaluating Molecular Properties Involved in Transport of Small Molecules in Stratum Corneum: A Quantitative Structure-Activity Relationship for Skin Permeability.

    Science.gov (United States)

    Chen, Chen-Peng; Chen, Chan-Cheng; Huang, Chia-Wen; Chang, Yen-Ching

    2018-04-15

    The skin permeability ( Kp ) defines the rate of a chemical penetrating across the stratum corneum. This value is widely used to quantitatively describe the transport of molecules in the outermost layer of epidermal skin and indicate the significance of skin absorption. This study defined a Kp quantitative structure-activity relationship (QSAR) based on 106 chemical substances of Kp measured using human skin and interpreted the molecular interactions underlying transport behavior of small molecules in the stratum corneum. The Kp QSAR developed in this study identified four molecular descriptors that described the molecular cyclicity in the molecule reflecting local geometrical environments, topological distances between pairs of oxygen and chlorine atoms, lipophilicity, and similarity to antineoplastics in molecular properties. This Kp QSAR considered the octanol-water partition coefficient to be a direct influence on transdermal movement of molecules. Moreover, the Kp QSAR identified a sub-domain of molecular properties initially defined to describe the antineoplastic resemblance of a compound as a significant factor in affecting transdermal permeation of solutes. This finding suggests that the influence of molecular size on the chemical's skin-permeating capability should be interpreted with other relevant physicochemical properties rather than being represented by molecular weight alone.

  7. Word Recognition in Auditory Cortex

    Science.gov (United States)

    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. Reader error, object recognition, and visual search

    Science.gov (United States)

    Kundel, Harold L.

    2004-05-01

    Small abnormalities such as hairline fractures, lung nodules and breast tumors are missed by competent radiologists with sufficient frequency to make them a matter of concern to the medical community; not only because they lead to litigation but also because they delay patient care. It is very easy to attribute misses to incompetence or inattention. To do so may be placing an unjustified stigma on the radiologists involved and may allow other radiologists to continue a false optimism that it can never happen to them. This review presents some of the fundamentals of visual system function that are relevant to understanding the search for and the recognition of small targets embedded in complicated but meaningful backgrounds like chests and mammograms. It presents a model for visual search that postulates a pre-attentive global analysis of the retinal image followed by foveal checking fixations and eventually discovery scanning. The model will be used to differentiate errors of search, recognition and decision making. The implications for computer aided diagnosis and for functional workstation design are discussed.

  9. [Comparative studies of face recognition].

    Science.gov (United States)

    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.

  10. Liver cell-targeted delivery of therapeutic molecules.

    Science.gov (United States)

    Kang, Jeong-Hun; Toita, Riki; Murata, Masaharu

    2016-01-01

    The liver is the largest internal organ in mammals and is involved in metabolism, detoxification, synthesis of proteins and lipids, secretion of cytokines and growth factors and immune/inflammatory responses. Hepatitis, alcoholic or non-alcoholic liver disease, hepatocellular carcinoma, hepatic veno-occlusive disease, and liver fibrosis and cirrhosis are the most common liver diseases. Safe and efficient delivery of therapeutic molecules (drugs, genes or proteins) into the liver is very important to increase the clinical efficacy of these molecules and to reduce their side effects in other organs. Several liver cell-targeted delivery systems have been developed and tested in vivo or ex vivo/in vitro. In this review, we discuss the literature concerning liver cell-targeted delivery systems, with a particular emphasis on the results of in vivo studies.

  11. A theoretical model investigation of peptide bond formation involving two water molecules in ribosome supports the two-step and eight membered ring mechanism

    International Nuclear Information System (INIS)

    Wang, Qiang; Gao, Jun; Zhang, Dongju; Liu, Chengbu

    2015-01-01

    Highlights: • We theoretical studied peptide bond formation reaction mechanism with two water molecules. • The first water molecule can decrease the reaction barriers by forming hydrogen bonds. • The water molecule mediated three-proton transfer mechanism is the favorable mechanism. • Our calculation supports the two-step and eight membered ring mechanism. - Abstract: The ribosome is the macromolecular machine that catalyzes protein synthesis. The kinetic isotope effect analysis reported by Strobel group supports the two-step mechanism. However, the destination of the proton originating from the nucleophilic amine is uncertain. A computational simulation of different mechanisms including water molecules is carried out using the same reaction model and theoretical level. Formation the tetrahedral intermediate with proton transfer from nucleophilic nitrogen, is the rate-limiting step when two water molecules participate in peptide bond formation. The first water molecule forming hydrogen bonds with O9′ and H15′ in the A site can decrease the reaction barriers. Combined with results of the solvent isotope effects analysis, we conclude that the three-proton transfer mechanism in which water molecule mediate the proton shuttle between amino and carbon oxygen in rate-limiting step is the favorable mechanism. Our results will shield light on a better understand the reaction mechanism of ribosome

  12. DNAzyme Feedback Amplification: Relaying Molecular Recognition to Exponential DNA Amplification.

    Science.gov (United States)

    Liu, Meng; Yin, Qingxin; McConnell, Erin M; Chang, Yangyang; Brennan, John D; Li, Yingfu

    2018-03-26

    Technologies capable of linking DNA amplification to molecular recognition are very desirable for ultrasensitive biosensing applications. We have developed a simple but powerful isothermal DNA amplification method, termed DNAzyme feedback amplification (DFA), that is capable of relaying molecular recognition to exponential DNA amplification. The method incorporates both an RNA-cleaving DNAzyme (RCD) and rolling circle amplification (RCA) carried out by a special DNA polymerase using a circular DNA template. DFA begins with a stimulus-dependent RCA reaction, producing tandemly linked RCDs in long-chain DNA products. These RCDs cleave an RNA-containing DNA sequence to form additional primers that hybridize to the circular DNA molecule, giving rise to DNA assemblies that act as the new inputs for RCA. The RCA reaction and the cleavage event keep on feeding each other autonomously, resulting in exponential growth of repetitive DNA sequences that can be easily detected. This method can be used for the detection of both nucleic acid based targets and non-nucleic acid analytes. In this article, we discuss the conceptual framework of the feedback amplification approach, the essential features of this method as well as remaining challenges and possible solutions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Pyoverdine, the Major Siderophore in Pseudomonas aeruginosa, Evades NGAL Recognition

    Directory of Open Access Journals (Sweden)

    Mary E. Peek

    2012-01-01

    Full Text Available Pseudomonas aeruginosa is the most common pathogen that persists in the cystic fibrosis lungs. Bacteria such as P. aeruginosa secrete siderophores (iron-chelating molecules and the host limits bacterial growth by producing neutrophil-gelatinase-associated lipocalin (NGAL that specifically scavenges bacterial siderophores, therefore preventing bacteria from establishing infection. P. aeruginosa produces a major siderophore known as pyoverdine, found to be important for bacterial virulence and biofilm development. We report that pyoverdine did not bind to NGAL, as measured by tryptophan fluorescence quenching, while enterobactin bound to NGAL effectively causing a strong response. The experimental data indicate that pyoverdine evades NGAL recognition. We then employed a molecular modeling approach to simulate the binding of pyoverdine to human NGAL using NGAL’s published crystal structures. The docking of pyoverdine to NGAL predicted nine different docking positions; however, neither apo- nor ferric forms of pyoverdine docked into the ligand-binding site in the calyx of NGAL where siderophores are known to bind. The molecular modeling results offer structural support that pyoverdine does not bind to NGAL, confirming the results obtained in the tryptophan quenching assay. The data suggest that pyoverdine is a stealth siderophore that evades NGAL recognition allowing P. aeruginosa to establish chronic infections in CF lungs.

  14. Is having similar eye movement patterns during face learning and recognition beneficial for recognition performance? Evidence from hidden Markov modeling.

    Science.gov (United States)

    Chuk, Tim; Chan, Antoni B; Hsiao, Janet H

    2017-12-01

    The hidden Markov model (HMM)-based approach for eye movement analysis is able to reflect individual differences in both spatial and temporal aspects of eye movements. Here we used this approach to understand the relationship between eye movements during face learning and recognition, and its association with recognition performance. We discovered holistic (i.e., mainly looking at the face center) and analytic (i.e., specifically looking at the two eyes in addition to the face center) patterns during both learning and recognition. Although for both learning and recognition, participants who adopted analytic patterns had better recognition performance than those with holistic patterns, a significant positive correlation between the likelihood of participants' patterns being classified as analytic and their recognition performance was only observed during recognition. Significantly more participants adopted holistic patterns during learning than recognition. Interestingly, about 40% of the participants used different patterns between learning and recognition, and among them 90% switched their patterns from holistic at learning to analytic at recognition. In contrast to the scan path theory, which posits that eye movements during learning have to be recapitulated during recognition for the recognition to be successful, participants who used the same or different patterns during learning and recognition did not differ in recognition performance. The similarity between their learning and recognition eye movement patterns also did not correlate with their recognition performance. These findings suggested that perceptuomotor memory elicited by eye movement patterns during learning does not play an important role in recognition. In contrast, the retrieval of diagnostic information for recognition, such as the eyes for face recognition, is a better predictor for recognition performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Dissociation between recognition and detection advantage for facial expressions: a meta-analysis.

    Science.gov (United States)

    Nummenmaa, Lauri; Calvo, Manuel G

    2015-04-01

    Happy facial expressions are recognized faster and more accurately than other expressions in categorization tasks, whereas detection in visual search tasks is widely believed to be faster for angry than happy faces. We used meta-analytic techniques for resolving this categorization versus detection advantage discrepancy for positive versus negative facial expressions. Effect sizes were computed on the basis of the r statistic for a total of 34 recognition studies with 3,561 participants and 37 visual search studies with 2,455 participants, yielding a total of 41 effect sizes for recognition accuracy, 25 for recognition speed, and 125 for visual search speed. Random effects meta-analysis was conducted to estimate effect sizes at population level. For recognition tasks, an advantage in recognition accuracy and speed for happy expressions was found for all stimulus types. In contrast, for visual search tasks, moderator analysis revealed that a happy face detection advantage was restricted to photographic faces, whereas a clear angry face advantage was found for schematic and "smiley" faces. Robust detection advantage for nonhappy faces was observed even when stimulus emotionality was distorted by inversion or rearrangement of the facial features, suggesting that visual features primarily drive the search. We conclude that the recognition advantage for happy faces is a genuine phenomenon related to processing of facial expression category and affective valence. In contrast, detection advantages toward either happy (photographic stimuli) or nonhappy (schematic) faces is contingent on visual stimulus features rather than facial expression, and may not involve categorical or affective processing. (c) 2015 APA, all rights reserved).

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

    Science.gov (United States)

    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.…

  17. TCRα-TCRβ pairing controls recognition of CD1d and directs the development of adipose NKT cells.

    Science.gov (United States)

    Vieth, Joshua A; Das, Joy; Ranaivoson, Fanomezana M; Comoletti, Davide; Denzin, Lisa K; Sant'Angelo, Derek B

    2017-01-01

    The interaction between the T cell antigen receptor (TCR) expressed by natural killer T cells (NKT cells) and the antigen-presenting molecule CD1d is distinct from interactions between the TCR and major histocompatibility complex (MHC). Our molecular modeling suggested that a hydrophobic patch created after TCRα-TCRβ pairing has a role in maintaining the conformation of the NKT cell TCR. Disruption of this patch ablated recognition of CD1d by the NKT cell TCR but not interactions of the TCR with MHC. Partial disruption of the patch, while permissive to the recognition of CD1d, significantly altered NKT cell development, which resulted in the selective accumulation of adipose-tissue-resident NKT cells. These results indicate that a key component of the TCR is essential for the development of a distinct population of NKT cells.

  18. Small Molecules Affect Human Dental Pulp Stem Cell Properties Via Multiple Signaling Pathways

    Science.gov (United States)

    Al-Habib, Mey; Yu, Zongdong

    2013-01-01

    One fundamental issue regarding stem cells for regenerative medicine is the maintenance of stem cell stemness. The purpose of the study was to test whether small molecules can enhance stem cell properties of mesenchymal stem cells (MSCs) derived from human dental pulp (hDPSCs), which have potential for multiple clinical applications. We identified the effects of small molecules (Pluripotin (SC1), 6-bromoindirubin-3-oxime and rapamycin) on the maintenance of hDPSC properties in vitro and the mechanisms involved in exerting the effects. Primary cultures of hDPSCs were exposed to optimal concentrations of these small molecules. Treated hDPSCs were analyzed for their proliferation, the expression levels of pluripotent and MSC markers, differentiation capacities, and intracellular signaling activations. We found that small molecule treatments decreased cell proliferation and increased the expression of STRO-1, NANOG, OCT4, and SOX2, while diminishing cell differentiation into odonto/osteogenic, adipogenic, and neurogenic lineages in vitro. These effects involved Ras-GAP-, ERK1/2-, and mTOR-signaling pathways, which may preserve the cell self-renewal capacity, while suppressing differentiation. We conclude that small molecules appear to enhance the immature state of hDPSCs in culture, which may be used as a strategy for adult stem cell maintenance and extend their capacity for regenerative applications. PMID:23573877

  19. Molecularly imprinted poly (methacrylamide-co-methacrylic acid) composite membranes for recognition of curcumin

    International Nuclear Information System (INIS)

    Wang Ping; Hu Wenming; Su Weike

    2008-01-01

    In this study, molecularly imprinted poly (methacrylamide-co-methacrylic acid) composite membranes with different ratio of methacrylamide (MAM) versus methacrylic acid (MAA) were prepared via UV initiated photo-copolymerization on the commercial filter paper. Curcumin was chosen as the template molecule. Infra-red (IR) spectroscopy was used to study the binding mechanism between the imprinted sites and the templates. The morphology of the resultant membranes was visualized by scanning electron microscopy (SEM). Static equilibrium binding and recognition properties of the imprinted composite membranes to curcumin (cur-I) and its analogues demethoxycurcumin (cur-II) or bisdemethoxycurcumin (cur-III) were tested. The results showed that curcumin-imprinted membranes had the best recognition ability to curcumin compared to its analogues. From the results, the biggest selectivity factor of α cur-I/cur-II and α cur-I/cur-III were 1.50 and 5.94, and they were obtained from the composite membranes in which MAM/MAA were 1:4 and 0:1, respectively. The results of this study implied that the molecularly imprinted composite membranes could be used as separation membranes for curcumin enrichment

  20. Lipid recognition propensities of amino acids in membrane proteins from atomic resolution data

    Directory of Open Access Journals (Sweden)

    Morita Mizuki

    2011-12-01

    Full Text Available Abstract Background Protein-lipid interactions play essential roles in the conformational stability and biological functions of membrane proteins. However, few of the previous computational studies have taken into account the atomic details of protein-lipid interactions explicitly. Results To gain an insight into the molecular mechanisms of the recognition of lipid molecules by membrane proteins, we investigated amino acid propensities in membrane proteins for interacting with the head and tail groups of lipid molecules. We observed a common pattern of lipid tail-amino acid interactions in two different data sources, crystal structures and molecular dynamics simulations. These interactions are largely explained by general lipophilicity, whereas the preferences for lipid head groups vary among individual proteins. We also found that membrane and water-soluble proteins utilize essentially an identical set of amino acids for interacting with lipid head and tail groups. Conclusions We showed that the lipophilicity of amino acid residues determines the amino acid preferences for lipid tail groups in both membrane and water-soluble proteins, suggesting that tightly-bound lipid molecules and lipids in the annular shell interact with membrane proteins in a similar manner. In contrast, interactions between lipid head groups and amino acids showed a more variable pattern, apparently constrained by each protein's specific molecular function.