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Sample records for bacterial signal recognition

  1. Bacterial and Fungal Pattern Recognition Receptors in Homologous Innate Signaling Pathways of Insects and Mammals

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    Bethany A Stokes

    2015-01-01

    Full Text Available In response to bacterial and fungal infections in insects and mammals, distinct families of innate immune pattern recognition receptors initiate highly complex intracellular signaling cascades. Those cascades induce a variety of immune functions that restrain the spread of microbes in the host. Insect and mammalian innate immune receptors include molecules that recognize conserved microbial molecular patterns. Innate immune recognition leads to the recruitment of adaptor molecules forming multi-protein complexes that include kinases, transcription factors and other regulatory molecules. Innate immune signaling cascades induce the expression of genes encoding antimicrobial peptides and other key factors that mount and regulate the immune response against microbial challenge. In this review, we summarize our current understanding of the bacterial and fungal pattern recognition receptors for homologous innate signaling pathways of insects and mammals in an effort to provide a framework for future studies.

  2. Predominant membrane localization is an essential feature of the bacterial signal recognition particle receptor

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    Graumann Peter

    2009-11-01

    Full Text Available Abstract Background The signal recognition particle (SRP receptor plays a vital role in co-translational protein targeting, because it connects the soluble SRP-ribosome-nascent chain complex (SRP-RNCs to the membrane bound Sec translocon. The eukaryotic SRP receptor (SR is a heterodimeric protein complex, consisting of two unrelated GTPases. The SRβ subunit is an integral membrane protein, which tethers the SRP-interacting SRα subunit permanently to the endoplasmic reticulum membrane. The prokaryotic SR lacks the SRβ subunit and consists of only the SRα homologue FtsY. Strikingly, although FtsY requires membrane contact for functionality, cell fractionation studies have localized FtsY predominantly to the cytosolic fraction of Escherichia coli. So far, the exact function of the soluble SR in E. coli is unknown, but it has been suggested that, in contrast to eukaryotes, the prokaryotic SR might bind SRP-RNCs already in the cytosol and only then initiates membrane targeting. Results In the current study we have determined the contribution of soluble FtsY to co-translational targeting in vitro and have re-analysed the localization of FtsY in vivo by fluorescence microscopy. Our data show that FtsY can bind to SRP-ribosome nascent chains (RNCs in the absence of membranes. However, these soluble FtsY-SRP-RNC complexes are not efficiently targeted to the membrane. In contrast, we observed effective targeting of SRP-RNCs to membrane-bond FtsY. These data show that soluble FtsY does not contribute significantly to cotranslational targeting in E. coli. In agreement with this observation, our in vivo analyses of FtsY localization in bacterial cells by fluorescence microscopy revealed that the vast majority of FtsY was localized to the inner membrane and that soluble FtsY constituted only a negligible species in vivo. Conclusion The exact function of the SRP receptor (SR in bacteria has so far been enigmatic. Our data show that the bacterial SR is

  3. Quantum Pattern Recognition of Classical Signal

    OpenAIRE

    Pang, Chao-Yang; Ding, Cong-Bao; Hu, Ben-Qiong

    2007-01-01

    It's the key research topic of signal processing that recognizing genuine targets real time from the disturbed signal which has giant amount of data. A quantum algorithm for pattern recognition of classical signal which has time complexity O(sqrt(N)) is presented in this paper. Key Words: Pattern recognition, Grover's algorithm, Rotation on subspace

  4. Automatic modulation recognition of communication signals

    CERN Document Server

    Azzouz, Elsayed Elsayed

    1996-01-01

    Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

  5. Partially Supervised Approach in Signal Recognition

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    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.

  6. ECG Signal Feature Selection for Emotion Recognition

    OpenAIRE

    Lichen Xun; Gang Zheng

    2013-01-01

    This paper aims to study the selection of features based on ECG in emotion recognition. In the process of features selection, we start from existing feature selection algorithm, and pay special attention to some of the intuitive value on ECG waveform as well. Through the use of ANOVA and heuristic search, we picked out the different features to distinguish joy and pleasure these two emotions, then we combine this with pathological analysis of ECG signals by the view of the medical experts to ...

  7. Recognition of bacterial plant pathogens: local, systemic and transgenerational immunity.

    Science.gov (United States)

    Henry, Elizabeth; Yadeta, Koste A; Coaker, Gitta

    2013-09-01

    Bacterial pathogens can cause multiple plant diseases and plants rely on their innate immune system to recognize and actively respond to these microbes. The plant innate immune system comprises extracellular pattern recognition receptors that recognize conserved microbial patterns and intracellular nucleotide binding leucine-rich repeat (NLR) proteins that recognize specific bacterial effectors delivered into host cells. Plants lack the adaptive immune branch present in animals, but still afford flexibility to pathogen attack through systemic and transgenerational resistance. Here, we focus on current research in plant immune responses against bacterial pathogens. Recent studies shed light onto the activation and inactivation of pattern recognition receptors and systemic acquired resistance. New research has also uncovered additional layers of complexity surrounding NLR immune receptor activation, cooperation and sub-cellular localizations. Taken together, these recent advances bring us closer to understanding the web of molecular interactions responsible for coordinating defense responses and ultimately resistance.

  8. ECG Signal Feature Selection for Emotion Recognition

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    Lichen Xun

    2013-01-01

    Full Text Available This paper aims to study the selection of features based on ECG in emotion recognition. In the process of features selection, we start from existing feature selection algorithm, and pay special attention to some of the intuitive value on ECG waveform as well. Through the use of ANOVA and heuristic search, we picked out the different features to distinguish joy and pleasure these two emotions, then we combine this with pathological analysis of ECG signals by the view of the medical experts to discuss the logic corresponding relation between ECG waveform and emotion distinguish. Through experiment, using the method in this paper we only picked out five features and reached 92% of accuracy rate in the recognition of joy and pleasure.

  9. Physical signals for protein-DNA recognition

    Science.gov (United States)

    Cao, Xiao-Qin; Zeng, Jia; Yan, Hong

    2009-09-01

    This paper discovers consensus physical signals around eukaryotic splice sites, transcription start sites, and replication origin start and end sites on a genome-wide scale based on their DNA flexibility profiles calculated by three different flexibility models. These salient physical signals are localized highly rigid and flexible DNAs, which may play important roles in protein-DNA recognition by the sliding search mechanism. The found physical signals lead us to a detailed hypothetical view of the search process in which a DNA-binding protein first finds a genomic region close to the target site from an arbitrary starting location by three-dimensional (3D) hopping and intersegment transfer mechanisms for long distances, and subsequently uses the one-dimensional (1D) sliding mechanism facilitated by the localized highly rigid DNAs to accurately locate the target flexible binding site within 30 bp (base pair) short distances. Guided by these physical signals, DNA-binding proteins rapidly search the entire genome to recognize a specific target site from the 3D to 1D pathway. Our findings also show that current promoter prediction programs (PPPs) based on DNA physical properties may suffer from lots of false positives because other functional sites such as splice sites and replication origins have similar physical signals as promoters do.

  10. A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation

    Science.gov (United States)

    Perception of pathogen-associated molecular patterns (PAMPs) by surface-localised pattern-recognition receptors (PRRs) is a key component of plant innate immunity. Most known plant PRRs are receptor kinases and initiation of PAMP-triggered immunity (PTI) signalling requires phosphorylation of the PR...

  11. Emotion Recognition through Physiological Signals for Human-Machine Communication

    OpenAIRE

    MAAOUI, Choubeila; PRUSKI, Alain

    2010-01-01

    In this paper we presented an approach to emotion recognition based on the processing of physiological signals. Physiological data was acquired in six different affective states and two pattern recognition methods have been tested: SVM method and Fisher linear discriminant. Recognition rates of about 90% were achieved for both classifiers. However, SVM classifier gives best results than Fisher discriminant using mixed features signals of different subjects. This study has shown that specific ...

  12. Biometric recognition system using low bandwidth ECG signals

    OpenAIRE

    Matos, André Cigarro; Lourenço, André Ribeiro; Nascimento, José M. P.

    2013-01-01

    Biometric recognition has recently emerged as part of applications where the privacy of the information is crucial, as in the health care field. This paper presents a biometric recognition system based on the Electrocardiographic signal (ECG). The proposed system is based on a state-of-the-art recognition method which extracts information from the frequency domain. In this paper we propose a new method to increase the spectral resolution of low bandwidth ECG signals due to the limited bandwid...

  13. A bacterial tyrosine phosphatase inhibits plant pattern recognition receptor activation.

    Science.gov (United States)

    Macho, Alberto P; Schwessinger, Benjamin; Ntoukakis, Vardis; Brutus, Alexandre; Segonzac, Cécile; Roy, Sonali; Kadota, Yasuhiro; Oh, Man-Ho; Sklenar, Jan; Derbyshire, Paul; Lozano-Durán, Rosa; Malinovsky, Frederikke Gro; Monaghan, Jacqueline; Menke, Frank L; Huber, Steven C; He, Sheng Yang; Zipfel, Cyril

    2014-03-28

    Innate immunity relies on the perception of pathogen-associated molecular patterns (PAMPs) by pattern-recognition receptors (PRRs) located on the host cell's surface. Many plant PRRs are kinases. Here, we report that the Arabidopsis receptor kinase EF-TU RECEPTOR (EFR), which perceives the elf18 peptide derived from bacterial elongation factor Tu, is activated upon ligand binding by phosphorylation on its tyrosine residues. Phosphorylation of a single tyrosine residue, Y836, is required for activation of EFR and downstream immunity to the phytopathogenic bacterium Pseudomonas syringae. A tyrosine phosphatase, HopAO1, secreted by P. syringae, reduces EFR phosphorylation and prevents subsequent immune responses. Thus, host and pathogen compete to take control of PRR tyrosine phosphorylation used to initiate antibacterial immunity.

  14. [Research progress on emotion recognition based on physiological signals].

    Science.gov (United States)

    Zhang, Di; Wan, Baikun; Ming, Dong

    2015-02-01

    Emotion recognition will be prosperious in multifarious applications, like distance education, healthcare, and human-computer interactions, etc. Emotions can be recognized from the behavior signals such as speech, facial expressions, gestures or the physiological signals such as electroencephalogram and electrocardiogram. Contrast to other methods, the physiological signals based emotion recognition can achieve more objective and effective results because it is almost impossible to be disguised. This paper introduces recent advancements in emotion research using physiological signals, specified to its emotion model, elicitation stimuli, feature extraction and classification methods. Finally the paper also discusses some research challenges and future developments. PMID:25997298

  15. Bacterial signaling and motility: Sure bets

    Energy Technology Data Exchange (ETDEWEB)

    Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2008-01-01

    The IX International Conference on Bacterial Locomotion and Signal Transduction (BLAST IX) was held from 14 to 19 January 2007 in Laughlin, NV, a town in the Mojave Desert on the Nevada-Arizona border near old Route 66 and along the banks of the Colorado River. This area is a home to rattlesnakes, sagebrush, abandoned gold mines, and compulsive gamblers. What better venue could scientists possibly dream of for a professional meeting? So there they were, about 190 scientists gathered in the Aquarius Casino Resort, the largest hotel and casino in Laughlin, discussing the latest advances in the field. Aside from a brief excursion to an abandoned gold mine and a dinner cruise on the Colorado River, the scientists focused on nothing but their data and hypotheses, in spirited arguments and rebuttals, and outlined their visions and future plans in a friendly and open environment. The BLAST IX program was dense, with nearly 50 talks and over 90 posters. For that reason, this meeting report will not attempt to be comprehensive; instead it will first provide general background information on the central topics of the meeting and then highlight only a few talks that were of special interest to us and hopefully to the wider scientific community. We will also attempt to articulate some of the future directions or perspectives to the best of our abilities. The best known and understood bacterial motility mechanism is swimming powered by flagella. The rotation of bacterial flagella drives this form of bacterial movement in an aqueous environment. A bacterial flagellum consists of a helical filament attached to the cell body through a complex structure known as the hook-basal body, which drives flagellar rotation. The essential components of the basal body are the MotA-MotB motor-stator proteins bound to the cytoplasmic membrane. These stator proteins interact with proteins that comprise the supramembrane and cytoplasmic rings, which are components of the motor imbedded in the

  16. Auditory signal design for automatic number plate recognition system

    NARCIS (Netherlands)

    Heydra, C.G.; Jansen, R.J.; Van Egmond, R.

    2014-01-01

    This paper focuses on the design of an auditory signal for the Automatic Number Plate Recognition system of Dutch national police. The auditory signal is designed to alert police officers of suspicious cars in their proximity, communicating priority level and location of the suspicious car and takin

  17. Stability of multispecies bacterial communities: signaling networks may stabilize microbiomes.

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    Ádám Kerényi

    Full Text Available Multispecies bacterial communities can be remarkably stable and resilient even though they consist of cells and species that compete for environmental resources. In silico models suggest that common signals released into the environment may help selected bacterial species cluster at common locations and that sharing of public goods (i.e. molecules produced and released for mutual benefit can stabilize this coexistence. In contrast, unilateral eavesdropping on signals produced by a potentially invading species may protect a community by keeping invaders away from limited resources. Shared bacterial signals, such as those found in quorum sensing systems, may thus play a key role in fine tuning competition and cooperation within multi-bacterial communities. We suggest that in addition to metabolic complementarity, signaling dynamics may be important in further understanding complex bacterial communities such as the human, animal as well as plant microbiomes.

  18. Pattern Recognition of EEG Signals and Applications in Robotics

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-dong; CHENG Zhi-qiang; LI De-jun

    2006-01-01

    With the rapid development of brain computer interface (simply called BCI),electroencephalography (EEG) will be another interesting bio-electrical signal applied in robotics after EMG.In order to realize it finally,the accurate measurement and pattern recognition of EEG signal must be a very important and elementary research objective.Based on our current researches and some reports from the other international colleagues in the field,we deeply discuss the basic characteristics of EEG signal,the development and selection of EEG measurement system,feature extraction and recognition methods of EEG signal,and then review EEG's applications in robotics as well as the future research trends in this paper.

  19. Heartbeat Signal from Facial Video for Biometric Recognition

    OpenAIRE

    Haque, Mohammad Ahsanul; Nasrollahi, Kamal; Moeslund, Thomas B

    2015-01-01

    Different biometric traits such as face appearance and heartbeat signal from Electrocardiogram (ECG)/Phonocardiogram (PCG) are widely used in the human identity recognition. Recent advances in facial video based measurement of cardio-physiological parameters such as heartbeat rate, respiratory rate, and blood volume pressure provide the possibility of extracting heartbeat signal from facial video instead of using obtrusive ECG or PCG sensors in the body. This paper proposes the Heartbeat Sign...

  20. Intercepting Bacterial Indole Signaling with Flustramine Derivatives

    OpenAIRE

    Bunders, Cynthia A.; Minvielle, Marine J.; Worthington, Roberta J.; Ortiz, Minoshka; Cavanagh, John; Melander, Christian

    2011-01-01

    Indole signaling is one of the putative universal signaling networks in bacteria. We have investigated the use of desformylflustrabromine (dFBr) derivatives for the inhibition of biofilm formation through modulation of the indole-signaling network in E. coli and S. aureus. We have found dFBr derivatives that are 10-1000 times more active than indole itself, demonstrating that the flustramine family of indolic natural products represent a privileged scaffold for the design of molecules to cont...

  1. Oyster Electrophysiology: Electrocardiogram Signal Recognition and Interpretation

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    Frederico M. Batista

    2015-06-01

    Full Text Available After 100 years of published recording traces pertaining to the oyster electrocardiogram (ECG, we revisited the original experiments of Eiger (1913, using state-of-the-art electrophysiology recorders. Our aim was to confirm that a recordable ECG, similar to that of higher vertebrates, is present in the oyster heart. Portuguese oysters Crassostrea angulata, collected from the Guadiana estuary, Portugal, were used. The oysters were drilled through the right valve to reveal the pericardium. Gold and silver electrodes were placed through the hole and electrophysiological recordings were obtained. Stimulation of the oyster heart was performed in vivo and in vitro using a constant current power supply. Placement of electrodes around the heart revealed a trace that very closely matched the published ECG of Eiger (1913. However, we were unable to confirm that the recording was an ECG of the oyster heart. Moreover, measurements on isolated oyster hearts revealed a low conductivity (0.10 S m‒1. We did, however, record a depolarization signal from what we believe to be the visceral ganglia, and this preceded contractions of the oyster heart. Our findings indicate that so-called ECGs, previously recorded by [2] in Ostrea edulis, but also the “ECG” recorded by [4] in C. virginica from oyster hearts, are in fact an artifact arising from relative movement of the recording electrodes, giving rise to a baseline shift that mimics in some ways the P and QRS features of a typical ECG. Nevertheless, such recordings provide information pertaining to heart rate and are not without importance.

  2. Advances in signal processing and intelligent recognition systems

    CERN Document Server

    Gelbukh, Alexander; Mukhopadhyay, Jayanta

    2014-01-01

    This Edited Volume contains a selection of refereed and revised papers originally presented at the International Symposium on Signal Processing and Intelligent Recognition Systems (SIRS-2014), March 13-15, 2014, Trivandrum, India. The program committee received 134 submissions from 11 countries. Each paper was peer reviewed by at least three or more independent referees of the program committee and the 52 papers were finally selected. The papers offer stimulating insights into Pattern Recognition, Machine Learning and Knowledge-Based Systems; Signal and Speech Processing; Image and Video Processing; Mobile Computing and Applications and Computer Vision. The book is directed to the researchers and scientists engaged in various field of signal processing and related areas.  

  3. Pattern recognition for electroencephalographic signals based on continuous neural networks.

    Science.gov (United States)

    Alfaro-Ponce, M; Argüelles, A; Chairez, I

    2016-07-01

    This study reports the design and implementation of a pattern recognition algorithm to classify electroencephalographic (EEG) signals based on artificial neural networks (NN) described by ordinary differential equations (ODEs). The training method for this kind of continuous NN (CNN) was developed according to the Lyapunov theory stability analysis. A parallel structure with fixed weights was proposed to perform the classification stage. The pattern recognition efficiency was validated by two methods, a generalization-regularization and a k-fold cross validation (k=5). The classifier was applied on two different databases. The first one was made up by signals collected from patients suffering of epilepsy and it is divided in five different classes. The second database was made up by 90 single EEG trials, divided in three classes. Each class corresponds to a different visual evoked potential. The pattern recognition algorithm achieved a maximum correct classification percentage of 97.2% using the information of the entire database. This value was similar to some results previously reported when this database was used for testing pattern classification. However, these results were obtained when only two classes were considered for the testing. The result reported in this study used the whole set of signals (five different classes). In comparison with similar pattern recognition methods that even considered less number of classes, the proposed CNN proved to achieve the same or even better correct classification results.

  4. Emotion Recognition from Speech Signals and Perception of Music

    OpenAIRE

    Fernandez Pradier, Melanie

    2011-01-01

    This thesis deals with emotion recognition from speech signals. The feature extraction step shall be improved by looking at the perception of music. In music theory, different pitch intervals (consonant, dissonant) and chords are believed to invoke different feelings in listeners. The question is whether there is a similar mechanism between perception of music and perception of emotional speech. Our research will follow three stages. First, the relationship between speech and music at segment...

  5. Structural diversity of signal recognition particle RNAs in plastids

    OpenAIRE

    Rosenblad, Magnus Alm; Träger, Chantal; Schünemann, Danja

    2013-01-01

    One of the pathways for protein targeting to the plasma membrane in bacteria utilizes the co-translationally acting signal recognition particle (SRP), a universally conserved ribonucleoprotein complex consisting of a 54 kDa protein and a functional RNA. An interesting exception is the higher plant chloroplast SRP, which lacks the otherwise essential RNA component. Furthermore, green plant chloroplasts have an additional post-translational SRP-dependent transport system in which the chloroplas...

  6. Heartbeat Signal from Facial Video for Biometric Recognition

    DEFF Research Database (Denmark)

    Haque, Mohammad Ahsanul; Nasrollahi, Kamal; Moeslund, Thomas B.

    2015-01-01

    , and blood volume pressure provide the possibility of extracting heartbeat signal from facial video instead of using obtrusive ECG or PCG sensors in the body. This paper proposes the Heartbeat Signal from Facial Video (HSFV) as a new biometric trait for human identity recognition, for the first time...... to the best of our knowledge. Feature extraction from the HSFV is accomplished by employing Radon transform on a waterfall model of the replicated HSFV. The pairwise Minkowski distances are obtained from the Radon image as the features. The authentication is accomplished by a decision tree based supervised...

  7. Clinical detection and movement recognition of neuro signals

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-wen; YANG Yu-pu; XU Xiao-ming; HU Tian-pei; GAO Zhong-hua; ZHANG Jian; CHEN Tong-yi; CHEN Zhong-wei

    2005-01-01

    Neuro signal has many more advantages than myoelectricity in providing information for prosthesis control, and can be an ideal source for developing new prosthesis. In this work, by implanting intrafascicular electrode clinically in the amputee's upper extremity, collective signals from fascicules of three main nerves (radial nerve, ulnar nerve and medium nerve) were successfully detected with sufficient fidelity and without infection. Initial analysis of features under different actions was performed and movement recognition of detected samples was attempted. Singular value decomposition features (SVD) extracted from wavelet coefficients were used as inputs for neural network classifier to predict amputee's movement intentions. The whole training rate was up to 80.94% and the test rate was 56.87% without over-training. This result gives inspiring prospect that collective signals from fascicules of the three main nerves are feasible sources for controlling prosthesis. Ways for improving accuracy in developing prosthesis controlled by neuro signals are discussed in the end.

  8. HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors.

    Directory of Open Access Journals (Sweden)

    Michael V Airola

    Full Text Available HAMP domains are signal relay modules in >26,000 receptors of bacteria, eukaryotes, and archaea that mediate processes involved in chemotaxis, pathogenesis, and biofilm formation. We identify two HAMP conformations distinguished by a four- to two-helix packing transition at the C-termini that send opposing signals in bacterial chemoreceptors. Crystal structures of signal-locked mutants establish the observed structure-to-function relationships. Pulsed dipolar electron spin resonance spectroscopy of spin-labeled soluble receptors active in cells verify that the crystallographically defined HAMP conformers are maintained in the receptors and influence the structure and activity of downstream domains accordingly. Mutation of HR2, a key residue for setting the HAMP conformation and generating an inhibitory signal, shifts HAMP structure and receptor output to an activating state. Another HR2 variant displays an inverted response with respect to ligand and demonstrates the fine energetic balance between "on" and "off" conformers. A DExG motif found in membrane proximal HAMP domains is shown to be critical for responses to extracellular ligand. Our findings directly correlate in vivo signaling with HAMP structure, stability, and dynamics to establish a comprehensive model for HAMP-mediated signal relay that consolidates existing views on how conformational signals propagate in receptors. Moreover, we have developed a rational means to manipulate HAMP structure and function that may prove useful in the engineering of bacterial taxis responses.

  9. HAMP domain conformers that propagate opposite signals in bacterial chemoreceptors.

    Science.gov (United States)

    Airola, Michael V; Sukomon, Nattakan; Samanta, Dipanjan; Borbat, Peter P; Freed, Jack H; Watts, Kylie J; Crane, Brian R

    2013-01-01

    HAMP domains are signal relay modules in >26,000 receptors of bacteria, eukaryotes, and archaea that mediate processes involved in chemotaxis, pathogenesis, and biofilm formation. We identify two HAMP conformations distinguished by a four- to two-helix packing transition at the C-termini that send opposing signals in bacterial chemoreceptors. Crystal structures of signal-locked mutants establish the observed structure-to-function relationships. Pulsed dipolar electron spin resonance spectroscopy of spin-labeled soluble receptors active in cells verify that the crystallographically defined HAMP conformers are maintained in the receptors and influence the structure and activity of downstream domains accordingly. Mutation of HR2, a key residue for setting the HAMP conformation and generating an inhibitory signal, shifts HAMP structure and receptor output to an activating state. Another HR2 variant displays an inverted response with respect to ligand and demonstrates the fine energetic balance between "on" and "off" conformers. A DExG motif found in membrane proximal HAMP domains is shown to be critical for responses to extracellular ligand. Our findings directly correlate in vivo signaling with HAMP structure, stability, and dynamics to establish a comprehensive model for HAMP-mediated signal relay that consolidates existing views on how conformational signals propagate in receptors. Moreover, we have developed a rational means to manipulate HAMP structure and function that may prove useful in the engineering of bacterial taxis responses.

  10. Emotion recognition method using entropy analysis of EEG signals

    Directory of Open Access Journals (Sweden)

    Seyyed Abed Hosseini

    2011-08-01

    Full Text Available This paper proposes an emotion recognition system using EEG signals, therefore a new approach to emotion state analysis by approximate (ApEn and wavelet entropy (WE is described. We have used EEG signals recorded during emotion in five channels (FP1, FP2, T3, T4 and Pz, under pictures induction environment (calm-neutral and negative excited for participants. After a brief introduction to the concept, the ApEn and WE were extracted from two different EEG time series. The result showed that, the classification accuracy in two emotion states was 73.25% using the support vector machine (SVM classifier. The simulations showed that the classification accuracy is good and the proposed methods are effective. During an emotion, the EEG is less complex compared to the normal, indicating reduction in active neuronal process in the brain.

  11. RNA gymnastics in mammalian signal recognition particle assembly.

    Science.gov (United States)

    Wild, Klemens; Sinning, Irmgard

    2014-01-01

    More than one third of the cellular proteome is destined for incorporation into cell membranes or export from the cell. In all domains of life, the signal recognition particle (SRP) delivers these proteins to the membrane and protein traffic falls apart without SRP logistics. With the aid of a topogenic transport signal, SRP retrieves its cargo right at the ribosome, from where they are sorted to the translocation channel. Mammalian SRP is a ribonucleoprotein complex consisting of an SRP RNA of 300 nucleotides and 6 proteins bound to it. Assembly occurs in a hierarchical manner mainly in the nucleolus and only SRP54, which recognizes the signal sequence and regulates the targeting process, is added as the last component in the cytosol. Here we present an update on recent insights in the structure, function and dynamics of SRP RNA in SRP assembly with focus on the S domain, and present SRP as an example for the complex biogenesis of a rather small ribonucleoprotein particle. PMID:25692231

  12. Voiceless Bangla vowel recognition using sEMG signal.

    Science.gov (United States)

    Mostafa, S S; Awal, M A; Ahmad, M; Rashid, M A

    2016-01-01

    Some people cannot produce sound although their facial muscles work properly due to having problem in their vocal cords. Therefore, recognition of alphabets as well as sentences uttered by these voiceless people is a complex task. This paper proposes a novel method to solve this problem using non-invasive surface Electromyogram (sEMG). Firstly, eleven Bangla vowels are pronounced and sEMG signals are recorded at the same time. Different features are extracted and mRMR feature selection algorithm is then applied to select prominent feature subset from the large feature vector. After that, these prominent features subset is applied in the Artificial Neural Network for vowel classification. This novel Bangla vowel classification method can offer a significant contribution in voice synthesis as well as in speech communication. The result of this experiment shows an overall accuracy of 82.3 % with fewer features compared to other studies in different languages. PMID:27652095

  13. Perspective: Adhesion Mediated Signal Transduction in Bacterial Pathogens

    Science.gov (United States)

    Moorthy, Sudha; Keklak, Julia; Klein, Eric A.

    2016-01-01

    During the infection process, pathogenic bacteria undergo large-scale transcriptional changes to promote virulence and increase intrahost survival. While much of this reprogramming occurs in response to changes in chemical environment, such as nutrient availability and pH, there is increasing evidence that adhesion to host-tissue can also trigger signal transduction pathways resulting in differential gene expression. Determining the molecular mechanisms of adhesion-mediated signaling requires disentangling the contributions of chemical and mechanical stimuli. Here we highlight recent work demonstrating that surface attachment drives a transcriptional response in bacterial pathogens, including uropathogenic Escherichia coli (E. coli), and discuss the complexity of experimental design when dissecting the specific role of adhesion-mediated signaling during infection. PMID:26901228

  14. Feature Fusion Algorithm for Multimodal Emotion Recognition from Speech and Facial Expression Signal

    Directory of Open Access Journals (Sweden)

    Han Zhiyan

    2016-01-01

    Full Text Available In order to overcome the limitation of single mode emotion recognition. This paper describes a novel multimodal emotion recognition algorithm, and takes speech signal and facial expression signal as the research subjects. First, fuse the speech signal feature and facial expression signal feature, get sample sets by putting back sampling, and then get classifiers by BP neural network (BPNN. Second, measure the difference between two classifiers by double error difference selection strategy. Finally, get the final recognition result by the majority voting rule. Experiments show the method improves the accuracy of emotion recognition by giving full play to the advantages of decision level fusion and feature level fusion, and makes the whole fusion process close to human emotion recognition more, with a recognition rate 90.4%.

  15. A Study of BCI Signal Pattern Recognition by Using Quasi-Newton-SVM Method

    Institute of Scientific and Technical Information of China (English)

    YANG Chang-chun; MA Zheng-hua; SUN Yu-qiang; ZOU Ling

    2006-01-01

    The recognition of electroencephalogram (EEG) signals is the key of brain computer interface (BCI).Aimed at the problem that the recognition rate of EEG by using support vector machine (SVM) is low in BCI,based on the assumption that a well-defined physiological signal which also has a smooth form"hides" inside the noisy EEG signal,a Quasi-Newton-SVM recognition method based on Quasi-Newton method and SVM algorithm was presented.Firstly,the EEG signals were preprocessed by Quasi-Newton method and got the signals which were fit for SVM.Secondly,the preprocessed signals were classified by SVM method.The present simulation results indicated the Quasi-Newton-SVM approach improved the recognition rate compared with using SVM method; we also discussed the relationship between the artificial smooth signals and the classification errors.

  16. AUTOMATIC RECOGNITION OF BOTH INTER AND INTRA CLASSES OF DIGITAL MODULATED SIGNALS USING ARTIFICIAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    JIDE JULIUS POPOOLA

    2014-04-01

    Full Text Available In radio communication systems, signal modulation format recognition is a significant characteristic used in radio signal monitoring and identification. Over the past few decades, modulation formats have become increasingly complex, which has led to the problem of how to accurately and promptly recognize a modulation format. In addressing these challenges, the development of automatic modulation recognition systems that can classify a radio signal’s modulation format has received worldwide attention. Decision-theoretic methods and pattern recognition solutions are the two typical automatic modulation recognition approaches. While decision-theoretic approaches use probabilistic or likelihood functions, pattern recognition uses feature-based methods. This study applies the pattern recognition approach based on statistical parameters, using an artificial neural network to classify five different digital modulation formats. The paper deals with automatic recognition of both inter-and intra-classes of digitally modulated signals in contrast to most of the existing algorithms in literature that deal with either inter-class or intra-class modulation format recognition. The results of this study show that accurate and prompt modulation recognition is possible beyond the lower bound of 5 dB commonly acclaimed in literature. The other significant contribution of this paper is the usage of the Python programming language which reduces computational complexity that characterizes other automatic modulation recognition classifiers developed using the conventional MATLAB neural network toolbox.

  17. 2nd International Symposium on Signal Processing and Intelligent Recognition Systems

    CERN Document Server

    Bandyopadhyay, Sanghamitra; Krishnan, Sri; Li, Kuan-Ching; Mosin, Sergey; Ma, Maode

    2016-01-01

    This Edited Volume contains a selection of refereed and revised papers originally presented at the second International Symposium on Signal Processing and Intelligent Recognition Systems (SIRS-2015), December 16-19, 2015, Trivandrum, India. The program committee received 175 submissions. Each paper was peer reviewed by at least three or more independent referees of the program committee and the 59 papers were finally selected. The papers offer stimulating insights into biometrics, digital watermarking, recognition systems, image and video processing, signal and speech processing, pattern recognition, machine learning and knowledge-based systems. The book is directed to the researchers and scientists engaged in various field of signal processing and related areas. .

  18. Multiple neural network integration using a binary decision tree to improve the ECG signal recognition accuracy

    OpenAIRE

    Tran Hoai Linh; Pham Van Nam; Vuong Hoang Nam

    2014-01-01

    The paper presents a new system for ECG (ElectroCardioGraphy) signal recognition using different neural classifiers and a binary decision tree to provide one more processing stage to give the final recognition result. As the base classifiers, the three classical neural models, i.e., the MLP (Multi Layer Perceptron), modified TSK (Takagi-Sugeno-Kang) and the SVM (Support Vector Machine), will be applied. The coefficients in ECG signal decomposition using Hermite basis functions and the peak-to...

  19. Prompt recognition of brain states by their EEG signals

    DEFF Research Database (Denmark)

    Peters, B.O.; Pfurtscheller, G.; Flyvbjerg, H.

    1997-01-01

    Brain states corresponding to intention of movement of left and right index finger and right foot are classified by a ''committee'' of artificial neural networks processing individual channels of 56-electrode electroencephalograms (EEGs). Correct recognition is achieved in 83% of cases not previo......Brain states corresponding to intention of movement of left and right index finger and right foot are classified by a ''committee'' of artificial neural networks processing individual channels of 56-electrode electroencephalograms (EEGs). Correct recognition is achieved in 83% of cases...

  20. Sex recognition in brown skuas: do acoustic signals matter?

    NARCIS (Netherlands)

    Janicke, T.; Ritz, M.S.; Hahn, S.M.; Peter, H.-U.

    2007-01-01

    Bird vocalisations are often essential for sex recognition, especially in species that show little morphological sex dimorphism. Brown skuas (Catharacta antarctica lonnbergi), which exhibit uniform plumage across both sexes, emit three main calls: the long call, the alarm call and the contact call.

  1. Structural Basis for Conserved Regulation and Adaptation of the Signal Recognition Particle Targeting Complex.

    Science.gov (United States)

    Wild, Klemens; Bange, Gert; Motiejunas, Domantas; Kribelbauer, Judith; Hendricks, Astrid; Segnitz, Bernd; Wade, Rebecca C; Sinning, Irmgard

    2016-07-17

    The signal recognition particle (SRP) is a ribonucleoprotein complex with a key role in targeting and insertion of membrane proteins. The two SRP GTPases, SRP54 (Ffh in bacteria) and FtsY (SRα in eukaryotes), form the core of the targeting complex (TC) regulating the SRP cycle. The architecture of the TC and its stimulation by RNA has been described for the bacterial SRP system while this information is lacking for other domains of life. Here, we present the crystal structures of the GTPase heterodimers of archaeal (Sulfolobus solfataricus), eukaryotic (Homo sapiens), and chloroplast (Arabidopsis thaliana) SRP systems. The comprehensive structural comparison combined with Brownian dynamics simulations of TC formation allows for the description of the general blueprint and of specific adaptations of the quasi-symmetric heterodimer. Our work defines conserved external nucleotide-binding sites for SRP GTPase activation by RNA. Structural analyses of the GDP-bound, post-hydrolysis states reveal a conserved, magnesium-sensitive switch within the I-box. Overall, we provide a general model for SRP cycle regulation by RNA. PMID:27241309

  2. Bacteriophage adhesin-coated long-period gratings for bacterial lipopolysaccharide recognition

    Science.gov (United States)

    Koba, Marcin; Śmietana, Mateusz; Brzozowska, Ewa; Górska, Sabina; Mikulic, Predrag; Bock, Wojtek J.

    2014-05-01

    In this work we report an application of the optical fiber long-period gratings (LPGs) working near the dispersion turning point of higher order cladding modes for bacterial lipopolysaccharide (LPS) recognition. We show that when the LPG is functionalized with the bacteriophage adhesin, it is capable of very specific LPS detection. Thus, we compare label-free binding effect for specific to the adhesin LPS-positive and non-specific LPS-negative. The resonance wavelength shift induced by the LPS-positive reaches 2.9 nm, while for LPS-negative the shift is negligible. The LPG-based sensing structure allows for monitoring of the binding phenomenon in real time and with good accuracy.

  3. Neural Network Based Recognition of Signal Patterns in Application to Automatic Testing of Rails

    Directory of Open Access Journals (Sweden)

    Tomasz Ciszewski

    2006-01-01

    Full Text Available The paper describes the application of neural network for recognition of signal patterns in measuring data gathered by the railroad ultrasound testing car. Digital conversion of the measuring signal allows to store and process large quantities of data. The elaboration of smart, effective and automatic procedures recognizing the obtained patterns on the basisof measured signal amplitude has been presented. The test shows only two classes of pattern recognition. In authors’ opinion if we deliver big enough quantity of training data, presented method is applicable to a system that recognizes many classes.

  4. Multiple neural network integration using a binary decision tree to improve the ECG signal recognition accuracy

    Directory of Open Access Journals (Sweden)

    Tran Hoai Linh

    2014-09-01

    Full Text Available The paper presents a new system for ECG (ElectroCardioGraphy signal recognition using different neural classifiers and a binary decision tree to provide one more processing stage to give the final recognition result. As the base classifiers, the three classical neural models, i.e., the MLP (Multi Layer Perceptron, modified TSK (Takagi-Sugeno-Kang and the SVM (Support Vector Machine, will be applied. The coefficients in ECG signal decomposition using Hermite basis functions and the peak-to-peak periods of the ECG signals will be used as features for the classifiers. Numerical experiments will be performed for the recognition of different types of arrhythmia in the ECG signals taken from the MIT-BIH (Massachusetts Institute of Technology and Boston’s Beth Israel Hospital Arrhythmia Database. The results will be compared with individual base classifiers’ performances and with other integration methods to show the high quality of the proposed solution

  5. EMOTION RECOGNITION FROM SPEECH SIGNAL: REALIZATION AND AVAILABLE TECHNIQUES

    Directory of Open Access Journals (Sweden)

    NILIM JYOTI GOGOI

    2014-05-01

    Full Text Available The ability to detect human emotion from their speech is going to be a great addition in the field of human-robot interaction. The aim of the work is to build an emotion recognition system using Mel-frequency cepstral coefficients (MFCC and Gaussian mixture model (GMM classifier. Basically the purpose of the work is aimed at describing the best possible and available methods for recognizing emotion from an emotional speech. For that reason already existing techniques and used methods for feature extraction and pattern classification have been reviewed and discussed in this paper.

  6. Spectral Collaborative Representation based Classification for Hand Gestures recognition on Electromyography Signals

    OpenAIRE

    Boyali, Ali

    2015-01-01

    In this study, we introduce a novel variant and application of the Collaborative Representation based Classification in spectral domain for recognition of the hand gestures using the raw surface Electromyography signals. The intuitive use of spectral features are explained via circulant matrices. The proposed Spectral Collaborative Representation based Classification (SCRC) is able to recognize gestures with higher levels of accuracy for a fairly rich gesture set. The worst recognition result...

  7. Ethanolamine Signaling Promotes Salmonella Niche Recognition and Adaptation during Infection.

    OpenAIRE

    Anderson, Christopher J.; Clark, David E; Mazhar Adli; Kendall, Melissa M.

    2015-01-01

    Chemical and nutrient signaling are fundamental for all cellular processes, including interactions between the mammalian host and the microbiota, which have a significant impact on health and disease. Ethanolamine is an essential component of cell membranes and has profound signaling activity within mammalian cells by modulating inflammatory responses and intestinal physiology. Here, we describe a virulence-regulating pathway in which the foodborne pathogen Salmonella enterica serovar Typhimu...

  8. Ethanolamine Signaling Promotes Salmonella Niche Recognition and Adaptation during Infection

    OpenAIRE

    Anderson, Christopher J.; Clark, David E; Adli, Mazhar; Kendall, Melissa M.

    2015-01-01

    Chemical and nutrient signaling are fundamental for all cellular processes, including interactions between the mammalian host and the microbiota, which have a significant impact on health and disease. Ethanolamine is an essential component of cell membranes and has profound signaling activity within mammalian cells by modulating inflammatory responses and intestinal physiology. Here, we describe a virulence-regulating pathway in which the foodborne pathogen Salmonella enterica serovar Typhimu...

  9. Pattern recognition and prognostic methods in parametric signal models for early failure detection

    International Nuclear Information System (INIS)

    For early failure detection in critical devices it is important to use intelligent signal processing methods in learning systems, so that a process evaluation can be optimized already on the signal processing level. On the one hand, pattern recognition methods are useful. On the other hand, about surveillance structures with parametric signal models there are a lot of questions not solved. In this report, a boiling detection system of real acoustic signals is demonstrated, how to survey such a physical process by methods of pattern recognition with enclosed parametric signal models. By introduction of prognostic models, a decision in form of a classification process can be made in advance. A surveillance is performed by the developed methods and the results are presented. (orig.)

  10. Contribution to automatic speech recognition. Analysis of the direct acoustical signal. Recognition of isolated words and phoneme identification

    International Nuclear Information System (INIS)

    This report deals with the acoustical-phonetic step of the automatic recognition of the speech. The parameters used are the extrema of the acoustical signal (coded in amplitude and duration). This coding method, the properties of which are described, is simple and well adapted to a digital processing. The quality and the intelligibility of the coded signal after reconstruction are particularly satisfactory. An experiment for the automatic recognition of isolated words has been carried using this coding system. We have designed a filtering algorithm operating on the parameters of the coding. Thus the characteristics of the formants can be derived under certain conditions which are discussed. Using these characteristics the identification of a large part of the phonemes for a given speaker was achieved. Carrying on the studies has required the development of a particular methodology of real time processing which allowed immediate evaluation of the improvement of the programs. Such processing on temporal coding of the acoustical signal is extremely powerful and could represent, used in connection with other methods an efficient tool for the automatic processing of the speech.(author)

  11. Recognition and delivery of effector proteins into eukaryotic cells by bacterial secretion systems.

    Science.gov (United States)

    Cambronne, Eric D; Roy, Craig R

    2006-08-01

    The direct transport of virulence proteins from bacterium to host has emerged as a common strategy employed by Gram-negative pathogens to establish infections. Specialized secretion systems function to facilitate this process. The delivery of 'effector' proteins by these secretion systems is currently confined to two functionally similar but mechanistically distinct pathways, termed type III and type IV secretion. The type III secretion pathway is ancestrally related to the multiprotein complexes that assemble flagella, whereas the type IV mechanism probably emerged from the protein complexes that support conjugal transfer of DNA. Although both pathways serve to transport proteins from the bacterium to host, the recognition of the effector protein substrates and the secretion information contained in these proteins appear highly distinct. Here, we review the mechanisms involved in the selection of substrates by each of these transport systems and secretion signal information required for substrate transport. PMID:16734660

  12. Event recognition using signal spectrograms in long pulse experiments.

    Science.gov (United States)

    González, J; Ruiz, M; Vega, J; Barrera, E; Arcas, G; López, J M

    2010-10-01

    As discharge duration increases, real-time complex analysis of the signal becomes more important. In this context, data acquisition and processing systems must provide models for designing experiments which use event oriented plasma control. One example of advanced data analysis is signal classification. The off-line statistical analysis of a large number of discharges provides information to develop algorithms for the determination of the plasma parameters from measurements of magnetohydrodinamic waves, for example, to detect density fluctuations induced by the Alfvén cascades using morphological patterns. The need to apply different algorithms to the signals and to address different processing algorithms using the previous results necessitates the use of an event-based experiment. The Intelligent Test and Measurement System platform is an example of architecture designed to implement distributed data acquisition and real-time processing systems. The processing algorithm sequence is modeled using an event-based paradigm. The adaptive capacity of this model is based on the logic defined by the use of state machines in SCXML. The Intelligent Test and Measurement System platform mixes a local multiprocessing model with a distributed deployment of services based on Jini. PMID:21033990

  13. Event recognition using signal spectrograms in long pulse experiments

    International Nuclear Information System (INIS)

    As discharge duration increases, real-time complex analysis of the signal becomes more important. In this context, data acquisition and processing systems must provide models for designing experiments which use event oriented plasma control. One example of advanced data analysis is signal classification. The off-line statistical analysis of a large number of discharges provides information to develop algorithms for the determination of the plasma parameters from measurements of magnetohydrodinamic waves, for example, to detect density fluctuations induced by the Alfven cascades using morphological patterns. The need to apply different algorithms to the signals and to address different processing algorithms using the previous results necessitates the use of an event-based experiment. The Intelligent Test and Measurement System platform is an example of architecture designed to implement distributed data acquisition and real-time processing systems. The processing algorithm sequence is modeled using an event-based paradigm. The adaptive capacity of this model is based on the logic defined by the use of state machines in SCXML. The Intelligent Test and Measurement System platform mixes a local multiprocessing model with a distributed deployment of services based on Jini.

  14. An approach to emotion recognition in single-channel EEG signals: a mother child interaction

    Science.gov (United States)

    Gómez, A.; Quintero, L.; López, N.; Castro, J.

    2016-04-01

    In this work, we perform a first approach to emotion recognition from EEG single channel signals extracted in four (4) mother-child dyads experiment in developmental psychology. Single channel EEG signals are analyzed and processed using several window sizes by performing a statistical analysis over features in the time and frequency domains. Finally, a neural network obtained an average accuracy rate of 99% of classification in two emotional states such as happiness and sadness.

  15. Analysis of physiological signals for recognition of boredom, pain, and surprise emotions

    OpenAIRE

    Jang, Eun-Hye; Park, Byoung-Jun; Park, Mi-Sook; Kim, Sang-Hyeob; Sohn, Jin-Hun

    2015-01-01

    Background The aim of the study was to examine the differences of boredom, pain, and surprise. In addition to that, it was conducted to propose approaches for emotion recognition based on physiological signals. Methods Three emotions, boredom, pain, and surprise, are induced through the presentation of emotional stimuli and electrocardiography (ECG), electrodermal activity (EDA), skin temperature (SKT), and photoplethysmography (PPG) as physiological signals are measured to collect a dataset ...

  16. Characterization and expression analysis of a peptidoglycan recognition protein gene, SmPGRP2 in mucosal tissues of turbot (Scophthalmus maximus L.) following bacterial challenge.

    Science.gov (United States)

    Zhang, Linan; Gao, Chengbin; Liu, Fengqiao; Song, Lin; Su, Baofeng; Li, Chao

    2016-09-01

    Peptidoglycan recognition receptor proteins (PGRPs), a group of pattern recognition receptors (PRRs), can recognize peptidoglycan (PGN) of the bacteria cell wall and play an important role in host immune defense against pathogen infection. They are highly structurally conserved through evolution, but with different function in innate immunity between invertebrates and vertebrates. 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 PGRPs in mucosal immunity of teleost fish is still limited. In this study, we identified a PGRPs gene (SmPGRP2) of turbot and investigated its expression patterns in mucosal tissues after challenge with Gram-positive bacteria Streptococcus iniae and Gram-negative bacteria Vibrio anguillarum. Phylogenetic analysis showed the strongest relationship of turbot PGRP to halibut, which was consistent with their phylogenetic relationships. In addition, SmPGRP2 was ubiquitously expressed in turbot tissues, and constitutive expression levels were higher in classical immune tissues (including liver, spleen, and head-kidney) than mucosal tissues (intestine, gill and skin). After bacterial challenge, the expression of SmPGRP2 was induced and showed a general trend of up-regulation in mucosal tissues, except in intestine following V. anguillarum infection. These different expression patterns varied depending on both pathogen and tissue type, suggesting its distinct roles in the host immune response to bacterial pathogen. PMID:27461422

  17. An Online Full-Body Motion Recognition Method Using Sparse and Deficient Signal Sequences

    Directory of Open Access Journals (Sweden)

    Chengyu Guo

    2014-01-01

    Full Text Available This paper presents a method to recognize continuous full-body human motion online by using sparse, low-cost sensors. The only input signals needed are linear accelerations without any rotation information, which are provided by four Wiimote sensors attached to the four human limbs. Based on the fused hidden Markov model (FHMM and autoregressive process, a predictive fusion model (PFM is put forward, which considers the different influences of the upper and lower limbs, establishes HMM for each part, and fuses them using a probabilistic fusion model. Then an autoregressive process is introduced in HMM to predict the gesture, which enables the model to deal with incomplete signal data. In order to reduce the number of alternatives in the online recognition process, a graph model is built that rejects parts of motion types based on the graph structure and previous recognition results. Finally, an online signal segmentation method based on semantics information and PFM is presented to finish the efficient recognition task. The results indicate that the method is robust with a high recognition rate of sparse and deficient signals and can be used in various interactive applications.

  18. Evolution from the prokaryotic to the higher plant chloroplast signal recognition particle

    DEFF Research Database (Denmark)

    Träger, Chantal; Rosenblad, Magnus Alm; Ziehe, Dominik;

    2012-01-01

    The protein targeting signal recognition particle (SRP) pathway in chloroplasts of higher plants has undergone dramatic evolutionary changes. It disposed of its RNA, which is an essential SRP component in bacteria, and uses a unique chloroplast-specific protein cpSRP43. Nevertheless, homologs of ...

  19. Robust signal recognition algorithm based on machine learning in heterogeneous networks

    Institute of Scientific and Technical Information of China (English)

    Xiaokai Liu; Rong Li; Chenglin Zhao; Pengbiao Wang

    2016-01-01

    There are various heterogeneous networks for terminals to deliver a better quality of service. Signal system recognition and classification contribute a lot to the process. However, in low signal to noise ratio (SNR) circumstances or under time-varying multipath channels, the majority of the existing algorithms for signal recognition are already facing limitations. In this series, we present a robust signal recogni-tion method based upon the original and latest updated ver-sion of the extreme learning machine (ELM) to help users to switch between networks. The ELM utilizes signal characte- ristics to distinguish systems. The superiority of this algorithm lies in the random choices of hidden nodes and in the fact that it determines the output weights analyticaly, which result in lower complexity. Theoreticaly, the algorithm tends to ofer a good generalization performance at an extremely fast speed of learning. Moreover, we implement the GSM/WCDMA/LTE mod-els in the Matlab environment by using the Simulink tools. The simulations reveal that the signals can be recognized suc-cessfuly to achieve a 95% accuracy in a low SNR (0 dB) environment in the time-varying multipath Rayleigh fading channel.

  20. Finger curvature movement recognition interface technique using SEMG signals

    Directory of Open Access Journals (Sweden)

    Y. Itoh

    2007-08-01

    Full Text Available Purpose: Until recently, keyboard has been used as the primary input method for machinery operation system. But in recent years, numerous methods related to direct input interface have been developed. One of them is to measure the surface electric potential that generates on the skin surface during muscle contraction. Based on this fact, hand finger operation can also be recognized with the help of the surface muscle electric potential. The purpose of this study is to identify the hand finger operation using surface electromyogram (SEMG during crookedness state of the finger.Design/methodology/approach: Two electrodes (Ag-AgCl electrode were sticked randomly on the forearm muscles and the intensity of EMG signals at different muscles were measured for each crooked finger. Then depending on the intensity of the obtained electric potentials, a position was located and considered to have participated most actively during the crookedness state of that finger. Thus five locations on the forearm muscles were identified for five different fingers. Moreover, four different types of crookedness states were considered for each finger.Findings: In this experimental study, the electric current that generates on the skin during muscle activity was measured for different hand finger operations. As a result, it is found that there is a specified position related to the maximum intensity of EMG signals for each finger. Practical implications: This paper cleared that the amount of crookedness of each finger can also be recognized with the help of surface EMG. It could be used as a machine interface technology in the field of welfare equipments, robot hand operation, virtual reality, etc.Originality/value: The objective of this research project was to develop the method of recognizing the hand finger operation and their crookedness states from surface electromyogram (SEMG.

  1. Automatic recognition of radar signals based on time-frequency image shape character

    Directory of Open Access Journals (Sweden)

    Jian-dong zhu

    2013-05-01

    Full Text Available Radar signal recognition is one of the key technologies of modern electronic surveillance systems. Time-frequency image provides a new way for recognizing the radar signal. In this paper, a series of image processing methods containing image enhancement, image threshold binarization and mathematical morphology is utilized to extract the shape character of smoothed pseudo wigner-ville time-frequency distribution of radar signal. And then the identification of radar signal is realized by the character. Simulation results of eight kinds of typical radar signal demonstrate that when signal noise ratio (SNR is greater than -3 dB, the Legendre moments shape character of the time-frequency image is very stable. Moreover, the recognition rate by the character is more than 90 per cent except for the FRANK code signal when SNR > -3 dB. Test also show that the proposed method can effectively recognize radar signal with less character dimension through compared with exitsing algorithms.Defence Science Journal, 2013, 63(3, pp.308-314, DOI:http://dx.doi.org/10.14429/dsj.63.2404

  2. Bacterial chemoreceptors of different length classes signal independently.

    Science.gov (United States)

    Herrera Seitz, M Karina; Frank, Vered; Massazza, Diego A; Vaknin, Ady; Studdert, Claudia A

    2014-08-01

    Bacterial chemoreceptors sense environmental stimuli and govern cell movement by transmitting the information to the flagellar motors. The highly conserved cytoplasmic domain of chemoreceptors consists in an alpha-helical hairpin that forms in the homodimer a coiled-coil four-helix bundle. Several classes of chemoreceptors that differ in the length of the coiled-coil structure were characterized. Many bacterial species code for chemoreceptors that belong to different classes, but how these receptors are organized and function in the same cell remains an open question. E. coli cells normally code for single class chemoreceptors that form extended arrays based on trimers of dimers interconnected by the coupling protein CheW and the kinase CheA. This structure promotes effective coupling between the different receptors in the modulation of the kinase activity. In this work, we engineered functional derivatives of the Tsr chemoreceptor of E. coli that mimic receptors whose cytoplasmic domain is longer by two heptads. We found that these long Tsr receptors did not efficiently mix with the native receptors and appeared to function independently. Our results suggest that the assembly of membrane-bound receptors of different specificities into mixed clusters is dictated by the length-class to which the receptors belong, ensuring cooperative function only between receptors of the same class.

  3. Human Walking Pattern Recognition Based on KPCA and SVM with Ground Reflex Pressure Signal

    Directory of Open Access Journals (Sweden)

    Zhaoqin Peng

    2013-01-01

    Full Text Available Algorithms based on the ground reflex pressure (GRF signal obtained from a pair of sensing shoes for human walking pattern recognition were investigated. The dimensionality reduction algorithms based on principal component analysis (PCA and kernel principal component analysis (KPCA for walking pattern data compression were studied in order to obtain higher recognition speed. Classifiers based on support vector machine (SVM, SVM-PCA, and SVM-KPCA were designed, and the classification performances of these three kinds of algorithms were compared using data collected from a person who was wearing the sensing shoes. Experimental results showed that the algorithm fusing SVM and KPCA had better recognition performance than the other two methods. Experimental outcomes also confirmed that the sensing shoes developed in this paper can be employed for automatically recognizing human walking pattern in unlimited environments which demonstrated the potential application in the control of exoskeleton robots.

  4. Input–output robustness in simple bacterial signaling systems

    OpenAIRE

    Shinar, Guy; Milo, Ron; Martínez, María Rodríguez; Alon, Uri

    2007-01-01

    Biological signaling systems produce an output, such as the level of a phosphorylated protein, in response to defined input signals. The output level as a function of the input level is called the system's input–output relation. One may ask whether this input–output relation is sensitive to changes in the concentrations of the system's components, such as proteins and ATP. Because component concentrations often vary from cell to cell, it might be expected that the input–output relation will l...

  5. Analysis of the influence of sound signal processing parameters on the quality voice command recognition

    Directory of Open Access Journals (Sweden)

    L. P. Dyuzhayev

    2014-04-01

    Full Text Available Introduction. For the task of voice control over different devices recognition of single (isolated voice commands is required. Typically, this control method requires high reliability (at least 95% accuracy voice recognition. It should be noted that voice commands are often pronounced in high noisiness. All presently known methods and algorithms of speech recognition do not allow to clearly determine which parameters of sound signal can provide the best results. The main part. On the first level of voice recognition is about preprocessing and extracting of acoustic features that have a number of useful features – they are easily calculated, providing a compact representation of the voice commands that are resistant to noise interference; On the next level given command is looked for in the reference dictionary. To get MFCC coefficients input file has to be divided into frames. Each frame is measured by a window function and processed by discrete Fourier transform. The resulting representation of signal in the frequency domain is divided into ranges using a set of triangular filters. The last step is to perform discrete cosine transform. Method of dynamic time warping allows to get a value that is an inverse of degree of similarity between given command and a reference. Conclusions. Research has shown that in the field of voice commands recognition optimum results in terms of quality / performance can be achieved using the following parameters of sound signal processing:8 kHz sample rate, frame duration 70–120 ms, Hamming weighting function of a window, number of Fourier samples is 512.

  6. The time course of individual face recognition: A pattern analysis of ERP signals.

    Science.gov (United States)

    Nemrodov, Dan; Niemeier, Matthias; Mok, Jenkin Ngo Yin; Nestor, Adrian

    2016-05-15

    An extensive body of work documents the time course of neural face processing in the human visual cortex. However, the majority of this work has focused on specific temporal landmarks, such as N170 and N250 components, derived through univariate analyses of EEG data. Here, we take on a broader evaluation of ERP signals related to individual face recognition as we attempt to move beyond the leading theoretical and methodological framework through the application of pattern analysis to ERP data. Specifically, we investigate the spatiotemporal profile of identity recognition across variation in emotional expression. To this end, we apply pattern classification to ERP signals both in time, for any single electrode, and in space, across multiple electrodes. Our results confirm the significance of traditional ERP components in face processing. At the same time though, they support the idea that the temporal profile of face recognition is incompletely described by such components. First, we show that signals associated with different facial identities can be discriminated from each other outside the scope of these components, as early as 70ms following stimulus presentation. Next, electrodes associated with traditional ERP components as well as, critically, those not associated with such components are shown to contribute information to stimulus discriminability. And last, the levels of ERP-based pattern discrimination are found to correlate with recognition accuracy across subjects confirming the relevance of these methods for bridging brain and behavior data. Altogether, the current results shed new light on the fine-grained time course of neural face processing and showcase the value of novel methods for pattern analysis to investigating fundamental aspects of visual recognition. PMID:26973169

  7. Quantitative Assessment of the Efficiency of Physiological Signals in Emotional State Recognition for Healthcare Applications

    Directory of Open Access Journals (Sweden)

    B. Mojarradshafie

    2013-12-01

    Full Text Available signals. In this study, an experiment is conducted to elicit four emotional states (happiness, anger, sadness and relax in twenty four healthy subjects. The physiological signals such as ECG, SCL (Skin Conductivity Level, EMG and Respiration signal are recorded simultaneously. After necessary preprocessing for primary signals such as segmentation, filtering, smoothing, removing artifacts and removal of baseline drift, various features in time and frequency domain are extracted. Feature selection method is used to find best relevant features. Afterward, different dimension reduction algorithms and classification methods are used to compare the efficiency of different physiological signals in emotion recognition. The precision of classifications with different features is found to be higher than 70%. The results show that the different physiological signals have different ability to classify four given affective states. Our proposed methods can result in developing a robust emotional states recognition system for healthcare applications.

  8. FEM enhanced signal processing approach for pattern recognition in the SQUID based NDE system

    International Nuclear Information System (INIS)

    An efficient Non-Destructive Evaluation algorithm has been developed in order to extract the required information for pattern recognition of defects in the conductive samples. Using high-Tc gradiometer RF-SQUIDs in unshielded environments and incorporating an automated two dimensional non-magnetic scanning robot, samples with different intentional defects have been tested. We have used a developed noise cancellation approach for the improvement of the effectiveness of the used inverse-problem technique. In this approach we have used a well examined Finite Element Method (FEM) to apply a noise reduction filtering on the obtained raw magnetic image data before incorporating the signal processing analysis. By applying this noise cancellation filter and incorporating three different signal processing algorithms and comparing the results of the predicted images by the pattern of the intentionally made defects, we have investigated the ability of these methods for pattern recognition of unknown defects.

  9. FEM enhanced signal processing approach for pattern recognition in the SQUID based NDE system

    Energy Technology Data Exchange (ETDEWEB)

    Sarreshtedari, F; Jahed, N M S; Hosseni, N; Pourhashemi, A; Fardmanesh, M [Department of Electrical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Banzet, Marko; Schubert, Juergen, E-mail: fardmanesh@sharif.ed [Forschungszentrum Juelich, Institute of Bio and Nanosystems, 52425 Juelich (Germany)

    2010-06-01

    An efficient Non-Destructive Evaluation algorithm has been developed in order to extract the required information for pattern recognition of defects in the conductive samples. Using high-Tc gradiometer RF-SQUIDs in unshielded environments and incorporating an automated two dimensional non-magnetic scanning robot, samples with different intentional defects have been tested. We have used a developed noise cancellation approach for the improvement of the effectiveness of the used inverse-problem technique. In this approach we have used a well examined Finite Element Method (FEM) to apply a noise reduction filtering on the obtained raw magnetic image data before incorporating the signal processing analysis. By applying this noise cancellation filter and incorporating three different signal processing algorithms and comparing the results of the predicted images by the pattern of the intentionally made defects, we have investigated the ability of these methods for pattern recognition of unknown defects.

  10. Bacterial Molecular Signals in the Sinorhizobium fredii-Soybean Symbiosis

    Directory of Open Access Journals (Sweden)

    Francisco J. López-Baena

    2016-05-01

    Full Text Available Sinorhizobium (Ensifer fredii (S. fredii is a rhizobial species exhibiting a remarkably broad nodulation host-range. Thus, S. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as Glycyrrhiza uralensis and pigeon-pea. This capacity of adaptation to different symbioses makes the study of the molecular signals produced by S. fredii strains of increasing interest since it allows the analysis of their symbiotic role in different types of nodule. In this review, we analyze in depth different S. fredii molecules that act as signals in symbiosis, including nodulation factors, different surface polysaccharides (exopolysaccharides, lipopolysaccharides, cyclic glucans, and K-antigen capsular polysaccharides, and effectors delivered to the interior of the host cells through a symbiotic type 3 secretion system.

  11. ECG Signal Recognition based on Wavelet Transform Using Neural and Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    H. M. Abdul-Ridha

    2008-01-01

    Full Text Available This work presents aneural and fuzzy based ECG signal recognition system based on wavelet transform. The suitable coefficients that can be used as a feature for each fuzzy network or neural network is found using a proposed best basis technique. Using the proposed best bases reduces the dimension of the input vector and hence reduces the complexity of the classifier. The fuzzy network and the neural network parameters are learned using back propagation algorithm.

  12. Communicative Signals Promote Object Recognition Memory and Modulate the Right Posterior STS.

    Science.gov (United States)

    Redcay, Elizabeth; Ludlum, Ruth S; Velnoskey, Kayla R; Kanwal, Simren

    2016-01-01

    Detection of communicative signals is thought to facilitate knowledge acquisition early in life, but less is known about the role these signals play in adult learning or about the brain systems supporting sensitivity to communicative intent. The current study examined how ostensive gaze cues and communicative actions affect adult recognition memory and modulate neural activity as measured by fMRI. For both the behavioral and fMRI experiments, participants viewed a series of videos of an actress acting on one of two objects in front of her. Communicative context in the videos was manipulated in a 2 × 2 design in which the actress either had direct gaze (Gaze) or wore a visor (NoGaze) and either pointed at (Point) or reached for (Reach) one of the objects (target) in front of her. Participants then completed a recognition memory task with old (target and nontarget) objects and novel objects. Recognition memory for target objects in the Gaze conditions was greater than NoGaze, but no effects of gesture type were seen. Similarly, the fMRI video-viewing task revealed a significant effect of Gaze within right posterior STS (pSTS), but no significant effects of Gesture. Furthermore, pSTS sensitivity to Gaze conditions was related to greater memory for objects viewed in Gaze, as compared with NoGaze, conditions. Taken together, these results demonstrate that the ostensive, communicative signal of direct gaze preceding an object-directed action enhances recognition memory for attended items and modulates the pSTS response to object-directed actions. Thus, establishment of a communicative context through ostensive signals remains an important component of learning and memory into adulthood, and the pSTS may play a role in facilitating this type of social learning.

  13. ECG Signal Recognition based on Wavelet Transform Using Neural and Fuzzy Logic

    OpenAIRE

    H. M. Abdul-Ridha; Abduladhem Abdulkareem Ali

    2008-01-01

    This work presents aneural and fuzzy based ECG signal recognition system based on wavelet transform. The suitable coefficients that can be used as a feature for each fuzzy network or neural network is found using a proposed best basis technique. Using the proposed best bases reduces the dimension of the input vector and hence reduces the complexity of the classifier. The fuzzy network and the neural network parameters are learned using back propagation algorithm.

  14. Bacterial LuxR solos have evolved to respond to different molecules including signals from plants

    Directory of Open Access Journals (Sweden)

    Hitendra K. Patel

    2013-11-01

    Full Text Available A future challenge will be understanding the extensive communication that most likely takes place in bacterial interspecies and interkingdom signaling between plants and bacteria. A major bacterial inter-cellular signaling system in Gram-negative bacteria is LuxI/R quorum sensing (QS based on the production (via the LuxI-family proteins and detection (via the LuxR-family proteins of N-acyl homoserine lactones (AHLs signaling molecules. LuxR proteins which have the same modular structure of QS LuxRs but are devoid of a cognate LuxI AHL synthase are called solos. LuxR solos have been shown to be responsible to respond to exogenous AHLs produced by neighboring cells as well endogenously produced AHLs. It is now also evident that some LuxR proteins have evolved from the ability to binding AHLs and respond to other molecules/signals. For example, recent research has shown that a sub-family of LuxR solos responds to small molecules produced by plants. This indicates the presence of a uni-directional interkingdom signaling system occurring from plants to bacteria. In addition LuxR solos have now been also implicated to respond to endogenously produced signals which are not AHLs. In this Mini Review article we will discuss current trends and implications of the role of LuxR solos in bacterial responses to other signals using proteins related to AHL quorum sensing systems.

  15. Behavioral assessment of acoustic parameters relevant to signal recognition and preference in a vocal fish.

    Science.gov (United States)

    McKibben, J R; Bass, A H

    1998-12-01

    Acoustic signal recognition depends on the receiver's processing of the physical attributes of a sound. This study takes advantage of the simple communication sounds produced by plainfin midshipman fish to examine effects of signal variation on call recognition and preference. Nesting male midshipman generate both long duration (> 1 min) sinusoidal-like "hums" and short duration "grunts." The hums of neighboring males often overlap, creating beat waveforms. Presentation of humlike, single tone stimuli, but not grunts or noise, elicited robust attraction (phonotaxis) by gravid females. In two-choice tests, females differentiated and chose between acoustic signals that differed in duration, frequency, amplitude, and fine temporal content. Frequency preferences were temperature dependent, in accord with the known temperature dependence of hum fundamental frequency. Concurrent hums were simulated with two-tone beat stimuli, either presented from a single speaker or produced more naturally by interference between adjacent sources. Whereas certain single-source beats reduced stimulus attractiveness, beats which resolved into unmodulated tones at their sources did not affect preference. These results demonstrate that phonotactic assessment of stimulus relevance can be applied in a teleost fish, and that multiple signal parameters can affect receiver response in a vertebrate with relatively simple communication signals. PMID:9857511

  16. Moment-flux models for bacterial chemotaxis in large signal gradients.

    Science.gov (United States)

    Xue, Chuan; Yang, Xige

    2016-10-01

    Chemotaxis is a fundamental process in the life of many prokaryotic and eukaryotic cells. Chemotaxis of bacterial populations has been modeled by both individual-based stochastic models that take into account the biochemistry of intracellular signaling, and continuum PDE models that track the evolution of the cell density in space and time. Continuum models have been derived from individual-based models that describe intracellular signaling by a system of ODEs. The derivations rely on quasi-steady state approximations of the internal ODE system. While this assumption is valid if cell movement is subject to slowly changing signals, it is often violated if cells are exposed to rapidly changing signals. In the latter case current continuum models break down and do not match the underlying individual-based model quantitatively. In this paper, we derive new PDE models for bacterial chemotaxis in large signal gradients that involve not only the cell density and flux, but also moments of the intracellular signals as a measure of the deviation of cell's internal state from its steady state. The derivation is based on a new moment closure method without calling the quasi-steady state assumption of intracellular signaling. Numerical simulations suggest that the resulting model matches the population dynamics quantitatively for a much larger range of signals. PMID:26922437

  17. Critical roles of sea cucumber C-type lectin in non-self recognition and bacterial clearance.

    Science.gov (United States)

    Wei, Xiumei; Liu, Xiangquan; Yang, Jianmin; Wang, Sheng; Sun, Guohua; Yang, Jialong

    2015-08-01

    C-type lectin is one important pattern recognition receptor (PRR) that plays crucial roles in multiple immune responses. A C-type lectin from sea cucumber Apostichopus japonicus (AjCTL-1) was characterized in the present study. The amino acid sequence of AjCTL-1 shared high similarities with other C-type lectins from invertebrates and vertebrates. The C-type lectin domain (CTLD) of AjCTL-1 contained a Ca(2+)-binding site 2 and four conserved cysteine residues. AjCTL-1 mRNA expression patterns in tissues and after bacterial challenge were then analysed. Quantitative PCR revealed that AjCTL-1 mRNA was widely expressed in the tested tissues of healthy sea cucumber. The highest expression level occurred in gonad followed by body wall, coelomocytes, tentacle, intestinum and longitudinal muscle, and the lowest expression level was in respiratory tree. AjCTL-1 mRNA expression in coelomocytes was significantly induced by gram-negative Listonella anguillarum and gram-positive Micrococcus luteus, with different up-regulation patterns post-challenge. Recombinant AjCTL-1 exhibited the ability to bind peptidoglycan directly, agglutinate M. luteus, Staphylococcus aureus and Escherichia coli, in a Ca(2+)-dependant manner, and enhance the phagocytosis of coelomocytes against E. coli in vitro. The results indicated that AjCTL-1 could act as a PRR in Apostichopus japonicus and had critical roles in non-self recognition and bacterial clearance against invading microbes. PMID:26052017

  18. Synthesis of Multifunctional Cellulose Nanocrystals for Lectin Recognition and Bacterial Imaging

    OpenAIRE

    Zhou, Juan; Butchosa, Núria; Jayawardena, H. Surangi N.; Park, JaeHyeung; Zhou, Qi; Yan, Mingdi; Ramström, Olof

    2015-01-01

    Multifunctional cellulose nanocrystals have been synthesized and applied as a new type of glyconanomaterial in lectin binding and bacterial imaging. The cellulose nanocrystals were prepared by TEMPO-mediated oxidation and acidic hydrolysis, followed by functionalization with a quinolone fluorophore and carbohydrate ligands. The cellulose nanocrystals were subsequently applied in interaction studies with carbohydrate-binding proteins and in bacterial imaging. The results show that the function...

  19. Application of an automatic pattern recognition for aleatory signals for the surveillance of nuclear reactor and rotating machinery

    International Nuclear Information System (INIS)

    An automatic pattern recognition program PSDREC, developed for the surveillance of nuclear reactor and rotating machinery is described and the relevant theory is outlined. Pattern recognition analysis of noise signals is a powerful technique for assessing 'system normality' in dynamic systems. This program, with applies 8 statistical tests to calculated power spectral density (PSD) distribution, was earlier installed in a PDP-11/45 computer at IPEN. To analyse recorded signals from three systems, namely an operational BWR power reactor (neutron signals), a water pump and a diesel engine (vibration signals) this technique was used. Results of the tests are considered satisfactory. (Author)

  20. Urtica dioica modulates hippocampal insulin signaling and recognition memory deficit in streptozotocin induced diabetic mice.

    Science.gov (United States)

    Patel, Sita Sharan; Gupta, Sahil; Udayabanu, Malairaman

    2016-06-01

    Diabetes mellitus has been associated with functional abnormalities in the hippocampus and performance of cognitive function. Urtica dioica (UD) has been used in the treatment of diabetes. In our previous report we observed that UD extract attenuate diabetes mediated associative and spatial memory dysfunction. The present study aimed to evaluate the effect of UD extract on mouse model of diabetes-induced recognition memory deficit and explore the possible mechanism behind it. Streptozotocin (STZ) (50 mg/kg, i.p. consecutively for 5 days) was used to induce diabetes followed by UD extract (50 mg/kg, oral) or rosiglitazone (ROSI) (5 mg/kg, oral) administration for 8 weeks. STZ induced diabetic mice showed significant decrease in hippocampal insulin signaling and translocation of glucose transporter type 4 (GLUT4) to neuronal membrane resulting in cognitive dysfunction and hypolocomotion. UD treatment effectively improved hippocampal insulin signaling, glucose tolerance and recognition memory performance in diabetic mice, which was comparable to ROSI. Further, diabetes mediated oxidative stress and inflammation was reversed by chronic UD or ROSI administration. UD leaves extract acts via insulin signaling pathway and might prove to be effective for the diabetes mediated central nervous system complications. PMID:26767366

  1. Sound transmission and the recognition of temporally degraded sexual advertisement signals in Cope's gray treefrog (Hyla chrysoscelis)

    OpenAIRE

    Kuczynski, Michael C.; Vélez, Alejandro; Schwartz, Joshua J.; Bee, Mark A.

    2010-01-01

    Acoustic communication signals degrade as they propagate between signalers and receivers. While we generally understand the degrading effects of sound propagation on the structure of acoustic signals, we know considerably less about how receivers make behavioral decisions based on the perception of degraded signals in sonically and structurally complex habitats where communication occurs. In this study of acoustic mate recognition in Cope's gray treefrog, Hyla chrysoscelis (Cope 1880), we inv...

  2. Old concepts, new molecules and current approaches applied to the bacterial nucleotide signalling field.

    Science.gov (United States)

    Gründling, Angelika; Lee, Vincent T

    2016-11-01

    Signalling nucleotides are key molecules that help bacteria to rapidly coordinate cellular pathways and adapt to changes in their environment. During the past 10 years, the nucleotide signalling field has seen much excitement, as several new signalling nucleotides have been discovered in both eukaryotic and bacterial cells. The fields have since advanced quickly, aided by the development of important tools such as the synthesis of modified nucleotides, which, combined with sensitive mass spectrometry methods, allowed for the rapid identification of specific receptor proteins along with other novel genome-wide screening methods. In this review, we describe the principle concepts of nucleotide signalling networks and summarize the recent work that led to the discovery of the novel signalling nucleotides. We also highlight current approaches applied to the research in the field as well as resources and methodological advances aiding in a rapid identification of nucleotide-specific receptor proteins.This article is part of the themed issue 'The new bacteriology'. PMID:27672152

  3. A phenylalanine rotameric switch for signal-state control in bacterial chemoreceptors

    Science.gov (United States)

    Ortega, Davi R.; Yang, Chen; Ames, Peter; Baudry, Jerome; Parkinson, John S.; Zhulin, Igor B.

    2013-12-01

    Bacterial chemoreceptors are widely used as a model system for elucidating the molecular mechanisms of transmembrane signalling and have provided a detailed understanding of how ligand binding by the receptor modulates the activity of its associated kinase CheA. However, the mechanisms by which conformational signals move between signalling elements within a receptor dimer and how they control kinase activity remain unknown. Here, using long molecular dynamics simulations, we show that the kinase-activating cytoplasmic tip of the chemoreceptor fluctuates between two stable conformations in a signal-dependent manner. A highly conserved residue, Phe396, appears to serve as the conformational switch, because flipping of the stacked aromatic rings of an interacting F396-F396‧ pair in the receptor homodimer takes place concomitantly with the signal-related conformational changes. We suggest that interacting aromatic residues, which are common stabilizers of protein tertiary structure, might serve as rotameric molecular switches in other biological processes as well.

  4. Molecule Recognition Imaging and Highly Ordered Gold Nanoparticle Templating of Functional Bacterial S-Layer Nanoarrays

    Institute of Scientific and Technical Information of China (English)

    Jilin TANG; Andreas Ebner; Helga Badelt-Lichtblau; Christian Rankl; Michael Leitner; Hermann J.Gruber; Uwe B.Sleytr; Nicola Ilk; Peter Hinterdorfer

    2009-01-01

    @@ Molecular recognition between receptors and their cognate ligands plays an important role in life sciences.Such specific interactions include those between complementary strands of DNA,enzyme and substrate,antigen and antibody,lectin and carbohydrate,ligands and cell surface receptors as well as between cell adhesion proteins.

  5. Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Silke Neumann

    Full Text Available Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

  6. Cutting force signal pattern recognition using hybrid neural network in end milling

    Institute of Scientific and Technical Information of China (English)

    Song-Tae SEONG; Ko-Tae JO; Young-Moon LEE

    2009-01-01

    Under certain cutting conditions in end milling, the signs of cutting forces change from positive to negative during a revolution of the tool. The change of force direction causes the cutting dynamics to be unstable which results in chatter vibration. Therefore, cutting force signal monitoring and classification are needed to determine the optimal cutting conditions and to improve the efficiency of cut. Artificial neural networks are powerful tools for solving highly complex and nonlinear problems. It can be divided into supervised and unsupervised learning machines based on the availability of a teacher. Hybrid neural network was introduced with both of functions of multilayer perceptron (MLP) trained with the back-propagation algorithm for monitoring and detecting abnormal state, and self organizing feature map (SOFM) for treating huge datum such as image processing and pattern recognition, for predicting and classifying cutting force signal patterns simultaneously. The validity of the results is verified with cutting experiments and simulation tests.

  7. Unsupervised pattern recognition methods in ciders profiling based on GCE voltammetric signals.

    Science.gov (United States)

    Jakubowska, Małgorzata; Sordoń, Wanda; Ciepiela, Filip

    2016-07-15

    This work presents a complete methodology of distinguishing between different brands of cider and ageing degrees, based on voltammetric signals, utilizing dedicated data preprocessing procedures and unsupervised multivariate analysis. It was demonstrated that voltammograms recorded on glassy carbon electrode in Britton-Robinson buffer at pH 2 are reproducible for each brand. By application of clustering algorithms and principal component analysis visible homogenous clusters were obtained. Advanced signal processing strategy which included automatic baseline correction, interval scaling and continuous wavelet transform with dedicated mother wavelet, was a key step in the correct recognition of the objects. The results show that voltammetry combined with optimized univariate and multivariate data processing is a sufficient tool to distinguish between ciders from various brands and to evaluate their freshness. PMID:26948640

  8. G protein signalling involved in host recognition and mycoparasitismrelated chitinase expression in Trichoderma atroviride

    Institute of Scientific and Technical Information of China (English)

    Susanne Zeilinger; Barbara Reithner; Kurt Brunner; Valeria Scala; Isabel Peiβl; Matteo Lorito; Robert L Mach

    2004-01-01

    @@ Mycoparasitic species of Trichoderma are commercially applied as biological control agents against various fungal pathogens. The mycoparasitic interaction is host specific and includes recognition,attack and subsequent penetration and killing of the host. Investigations on the underlying events revealed that Trichoderma responds to multiple signals from the host (e. g. lectins or other ligands such as low molecular weight components released from the host's cell wall) and host attack is accompanied by morphological changes and the secretion of hydrolytic enzymes and antibiotics.Degradation of the cell wall of the host fungus is-besides glucanases and proteases-mainly achieved by chitinases. In vivo studies showed that the ech42 gene (encoding endochitinase 42) is expressed before physical contact of Trichoderma with its host, probably representing one of the earliest events in mycoparasitism, whereas Nag1 (N-acetylglucosaminidase) plays a key role in the general induction of the chitinolytic enzyme system of T. atroviride . Investigations on the responsible signal transduction pathways of T. atroviride led to the isolation of several genes encoding key components of the cAMP and MAP kinase signaling pathways, as alpha and β subunits of heterotrimeric G proteins, the regulatory subunit of cAMP-dependent protein kinase,adenylate cyclase, and three MAP kinases. Analysis of knockout mutants, generated by Agrobacterium-mediated transformation, revealed that at least two alpha-subunits of heterotrimeric G proteins are participating in mycoparasitism-related signal transduction. The Tga1 G alpha subunit was shown to be involved in mycoparasitism-related processes such as chitinase expression and overproduction of toxic secondary metabolites, whereas Tga3 was found to be completely avirulent showing defects in chitinase formation and host recognition.

  9. Structural basis for signal-sequence recognition by the translocase motor SecA determined by NMR

    NARCIS (Netherlands)

    Gelis, I.; Bonvin, A.M.J.J.; Keramisanou, D.; Koukaki, M.; Gouridis, G.; Karamanou, S.; Economou, A.; Kalodimos, C.G.

    2007-01-01

    Recognition of signal sequences by cognate receptors controls the entry of virtually all proteins to export pathways. Despite its importance, this process remains poorly understood. Here, we present the solution structure of a signal peptide bound to SecA, the 204 kDa ATPase motor of the Sec translo

  10. Entamoeba Clone-Recognition Experiments: Morphometrics, Aggregative Behavior, and Cell-Signaling Characterization.

    Science.gov (United States)

    Espinosa, Avelina; Paz-Y-Miño-C, Guillermo; Hackey, Meagan; Rutherford, Scott

    2016-05-01

    Studies on clone- and kin-discrimination in protists have proliferated during the past decade. We report clone-recognition experiments in seven Entamoeba lineages (E. invadens IP-1, E. invadens VK-1:NS, E. terrapinae, E. moshkovskii Laredo, E. moshkovskii Snake, E. histolytica HM-1:IMSS and E. dispar). First, we characterized morphometrically each clone (length, width, and cell-surface area) and documented how they differed statistically from one another (as per single-variable or canonical-discriminant analyses). Second, we demonstrated that amebas themselves could discriminate self (clone) from different (themselves vs. other clones). In mix-cell-line cultures between closely-related (E. invadens IP-1 vs. E. invadens VK-1:NS) or distant-phylogenetic clones (E. terrapinae vs. E. moshkovskii Laredo), amebas consistently aggregated with same-clone members. Third, we identified six putative cell-signals secreted by the amebas (RasGap/Ankyrin, coronin-WD40, actin, protein kinases, heat shock 70, and ubiquitin) and which known functions in Entamoeba spp. included: cell proliferation, cell adhesion, cell movement, and stress-induced encystation. To our knowledge, this is the first multi-clone characterization of Entamoeba spp. morphometrics, aggregative behavior, and cell-signaling secretion in the context of clone-recognition. Protists allow us to study cell-cell recognition from ecological and evolutionary perspectives. Modern protistan lineages can be central to studies about the origins and evolution of multicellularity. PMID:26990199

  11. Entamoeba Clone-Recognition Experiments: Morphometrics, Aggregative Behavior, and Cell-Signaling Characterization.

    Science.gov (United States)

    Espinosa, Avelina; Paz-Y-Miño-C, Guillermo; Hackey, Meagan; Rutherford, Scott

    2016-05-01

    Studies on clone- and kin-discrimination in protists have proliferated during the past decade. We report clone-recognition experiments in seven Entamoeba lineages (E. invadens IP-1, E. invadens VK-1:NS, E. terrapinae, E. moshkovskii Laredo, E. moshkovskii Snake, E. histolytica HM-1:IMSS and E. dispar). First, we characterized morphometrically each clone (length, width, and cell-surface area) and documented how they differed statistically from one another (as per single-variable or canonical-discriminant analyses). Second, we demonstrated that amebas themselves could discriminate self (clone) from different (themselves vs. other clones). In mix-cell-line cultures between closely-related (E. invadens IP-1 vs. E. invadens VK-1:NS) or distant-phylogenetic clones (E. terrapinae vs. E. moshkovskii Laredo), amebas consistently aggregated with same-clone members. Third, we identified six putative cell-signals secreted by the amebas (RasGap/Ankyrin, coronin-WD40, actin, protein kinases, heat shock 70, and ubiquitin) and which known functions in Entamoeba spp. included: cell proliferation, cell adhesion, cell movement, and stress-induced encystation. To our knowledge, this is the first multi-clone characterization of Entamoeba spp. morphometrics, aggregative behavior, and cell-signaling secretion in the context of clone-recognition. Protists allow us to study cell-cell recognition from ecological and evolutionary perspectives. Modern protistan lineages can be central to studies about the origins and evolution of multicellularity.

  12. Evolution of identity signals: frequency-dependent benefits of distinctive phenotypes used for individual recognition.

    Science.gov (United States)

    Sheehan, Michael J; Tibbetts, Elizabeth A

    2009-12-01

    Identifying broad-scale evolutionary processes that maintain phenotypic polymorphisms has been a major goal of modern evolutionary biology. There are numerous mechanisms, such as negative frequency-dependent selection, that may maintain polymorphisms, although it is unknown which mechanisms are prominent in nature. Traits used for individual recognition are strikingly variable and have evolved independently in numerous lineages, providing an excellent model to investigate which factors maintain ecologically relevant phenotypic polymorphisms. Theoretical models suggest that individuals may benefit by advertising their identities with distinctive, recognizable phenotypes. Here, we test the benefits of advertising one's identity with a distinctive phenotype. We manipulated the appearance of Polistes fuscatus paper wasp groups so that three individuals had the same appearance and one individual had a unique, easily recognizable appearance. We found that individuals with distinctive appearances received less aggression than individuals with nondistinctive appearances. Therefore, individuals benefit by advertising their identity with a unique phenotype. Our results provide a potential mechanism through which negative frequency-dependent selection may maintain the polymorphic identity signals in P. fuscatus. Given that recognition is important for many social interactions, selection for distinctive identity signals may be an underappreciated and widespread mechanism underlying the evolution of phenotypic polymorphisms in social taxa. PMID:19744121

  13. Cross-talk and information transfer in mammalian and bacterial signaling.

    Directory of Open Access Journals (Sweden)

    Samanthe M Lyons

    Full Text Available In mammalian and bacterial cells simple phosphorylation circuits play an important role in signaling. Bacteria have hundreds of two-component signaling systems that involve phosphotransfer between a receptor and a response regulator. In mammalian cells a similar pathway is the TGF-beta pathway, where extracellular TGF-beta ligands activate cell surface receptors that phosphorylate Smad proteins, which in turn activate many genes. In TGF-beta signaling the multiplicity of ligands begs the question as to whether cells can distinguish signals coming from different ligands, but transduced through a small set of Smads. Here we use information theory with stochastic simulations of networks to address this question. We find that when signals are transduced through only one Smad, the cell cannot distinguish between different levels of the external ligands. Increasing the number of Smads from one to two significantly improves information transmission as well as the ability to discriminate between ligands. Surprisingly, both total information transmitted and the capacity to discriminate between ligands are quite insensitive to high levels of cross-talk between the two Smads. Robustness against cross-talk requires that the average amplitude of the signals are large. We find that smaller systems, as exemplified by some two-component systems in bacteria, are significantly much less robust against cross-talk. For such system sizes phosphotransfer is also less robust against cross-talk than phosphorylation. This suggests that mammalian signal transduction can tolerate a high amount of cross-talk without degrading information content. This may have played a role in the evolution of new functionalities from small mutations in signaling pathways, allowed for the development of cross-regulation and led to increased overall robustness due to redundancy in signaling pathways. On the other hand the lack of cross-regulation observed in many bacterial two

  14. Recognition of signal peptide by protein translocation machinery in middle silk gland of silkworm Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    Xiuyang Guo; Yi Zhang; Xue Zhang; Shengpeng Wang; Changde Lu

    2008-01-01

    To investigate the functions of signal peptide in protein secretion in the middle silk gland of silkworm Bombyx mori,a series of recombinant Autographa californica multiple nucleopolyhedroviruses containing enhanced green fluorescent protein (egfp) gene,led by sericin-1 promoter and mutated signal peptide coding sequences,were constructed by region-deletions or single amino acid residue deletions.The recombinant Autographa californica multiple nucleopolyhedroviruses were injected into the hemocoele of newly ecdysed fifth-instar silkworm larvae.The expression and secretion of EGFP in the middle silk gland were examined by fluorescence microscopy and Western blot analysis.Results showed that even with a large part (up to 14 amino acid residues) of the ser-1 signal peptide deleted,the expressed EGFP could still be secreted into the cavity of the silk gland.Western blot analysis showed that shortening of the signal peptide from the C-terminal suppressed the maturation of pro-EGFP to EGFP.When 8 amino acid residues were deleted from the C-terminal of the signal peptide (mutant 13 aa),the secretion of EGFP was incomplete,implicating the importance of proper coupling of the h-region and c-region.The deletion of amino acid residue(s) in the h-region did not affect the secretion of EGFP,indicating that the recognition of signal peptide by translocation machinery was mainly by a structural domain,but not by special amino acid residue(s).Furthermore,the deletion of Arg2 or replacement with Asp in the n-region of the signal peptide did not influence secretion of EGFP,suggesting that a positive charge is not crucial.

  15. Real-time intelligent pattern recognition algorithm for surface EMG signals

    Directory of Open Access Journals (Sweden)

    Jahed Mehran

    2007-12-01

    Full Text Available Abstract Background Electromyography (EMG is the study of muscle function through the inquiry of electrical signals that the muscles emanate. EMG signals collected from the surface of the skin (Surface Electromyogram: sEMG can be used in different applications such as recognizing musculoskeletal neural based patterns intercepted for hand prosthesis movements. Current systems designed for controlling the prosthetic hands either have limited functions or can only be used to perform simple movements or use excessive amount of electrodes in order to achieve acceptable results. In an attempt to overcome these problems we have proposed an intelligent system to recognize hand movements and have provided a user assessment routine to evaluate the correctness of executed movements. Methods We propose to use an intelligent approach based on adaptive neuro-fuzzy inference system (ANFIS integrated with a real-time learning scheme to identify hand motion commands. For this purpose and to consider the effect of user evaluation on recognizing hand movements, vision feedback is applied to increase the capability of our system. By using this scheme the user may assess the correctness of the performed hand movement. In this work a hybrid method for training fuzzy system, consisting of back-propagation (BP and least mean square (LMS is utilized. Also in order to optimize the number of fuzzy rules, a subtractive clustering algorithm has been developed. To design an effective system, we consider a conventional scheme of EMG pattern recognition system. To design this system we propose to use two different sets of EMG features, namely time domain (TD and time-frequency representation (TFR. Also in order to decrease the undesirable effects of the dimension of these feature sets, principle component analysis (PCA is utilized. Results In this study, the myoelectric signals considered for classification consists of six unique hand movements. Features chosen for EMG signal

  16. E3 ubiquitin ligases Pellinos as regulators of pattern recognition receptor signaling and immune responses.

    Science.gov (United States)

    Medvedev, Andrei E; Murphy, Michael; Zhou, Hao; Li, Xiaoxia

    2015-07-01

    Pellinos are a family of E3 ubiquitin ligases discovered for their role in catalyzing K63-linked polyubiquitination of Pelle, an interleukin-1 (IL-1) receptor-associated kinase homolog in the Drosophila Toll pathway. Subsequent studies have revealed the central and non-redundant roles of mammalian Pellino-1, Pellino-2, and Pelino-3 in signaling pathways emanating from IL-1 receptors, Toll-like receptors, NOD-like receptors, T- and B-cell receptors. While Pellinos ability to interact with many signaling intermediates suggested their scaffolding roles, recent findings in mice expressing ligase-inactive Pellinos demonstrated the importance of Pellino ubiquitin ligase activity. Cell-specific functions of Pellinos have emerged, e.g. Pellino-1 being a negative regulator in T lymphocytes and a positive regulator in myeloid cells, and details of molecular regulation of receptor signaling by various members of the Pellino family have been revealed. In this review, we summarize current information about Pellino-mediated regulation of signaling by pattern recognition receptors, T-cell and B-cell receptors and tumor necrosis factor receptors, and discuss Pellinos roles in sepsis and infectious diseases, as well as in autoimmune, inflammatory, and allergic disorders. We also provide our perspective on the potential of targeting Pellinos with peptide- or small molecule-based drug compounds as a new therapeutic approach for septic shock and autoimmune pathologies.

  17. Recognition- and reactivity-based fluorescent probes for studying transition metal signaling in living systems.

    Science.gov (United States)

    Aron, Allegra T; Ramos-Torres, Karla M; Cotruvo, Joseph A; Chang, Christopher J

    2015-08-18

    Metals are essential for life, playing critical roles in all aspects of the central dogma of biology (e.g., the transcription and translation of nucleic acids and synthesis of proteins). Redox-inactive alkali, alkaline earth, and transition metals such as sodium, potassium, calcium, and zinc are widely recognized as dynamic signals, whereas redox-active transition metals such as copper and iron are traditionally thought of as sequestered by protein ligands, including as static enzyme cofactors, in part because of their potential to trigger oxidative stress and damage via Fenton chemistry. Metals in biology can be broadly categorized into two pools: static and labile. In the former, proteins and other macromolecules tightly bind metals; in the latter, metals are bound relatively weakly to cellular ligands, including proteins and low molecular weight ligands. Fluorescent probes can be useful tools for studying the roles of transition metals in their labile forms. Probes for imaging transition metal dynamics in living systems must meet several stringent criteria. In addition to exhibiting desirable photophysical properties and biocompatibility, they must be selective and show a fluorescence turn-on response to the metal of interest. To meet this challenge, we have pursued two general strategies for metal detection, termed "recognition" and "reactivity". Our design of transition metal probes makes use of a recognition-based approach for copper and nickel and a reactivity-based approach for cobalt and iron. This Account summarizes progress in our laboratory on both the development and application of fluorescent probes to identify and study the signaling roles of transition metals in biology. In conjunction with complementary methods for direct metal detection and genetic and/or pharmacological manipulations, fluorescent probes for transition metals have helped reveal a number of principles underlying transition metal dynamics. In this Account, we give three recent

  18. Estradiol-induced object recognition memory consolidation is dependent on activation of mTOR signaling in the dorsal hippocampus

    OpenAIRE

    Fortress, Ashley M.; Fan, Lu; Orr, Patrick T.; Zhao, Zaorui; Frick, Karyn M.

    2013-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is an important regulator of protein synthesis and is essential for various forms of hippocampal memory. Here, we asked whether the enhancement of object recognition memory consolidation produced by dorsal hippocampal infusion of 17β-estradiol (E2) is dependent on mTOR signaling in the dorsal hippocampus, and whether E2-induced mTOR signaling is dependent on dorsal hippocampal phosphatidylinositol 3-kinase (PI3K) and extracellular sig...

  19. Chemosensation of bacterial secondary metabolites modulates neuroendocrine signaling and behavior of C. elegans.

    Science.gov (United States)

    Meisel, Joshua D; Panda, Oishika; Mahanti, Parag; Schroeder, Frank C; Kim, Dennis H

    2014-10-01

    Discrimination between pathogenic and beneficial microbes is essential for host organism immunity and homeostasis. Here, we show that chemosensory detection of two secondary metabolites produced by Pseudomonas aeruginosa modulates a neuroendocrine signaling pathway that promotes avoidance behavior in the simple animal host Caenorhabditis elegans. Secondary metabolites phenazine-1-carboxamide and pyochelin activate a G-protein-signaling pathway in the ASJ chemosensory neuron pair that induces expression of the neuromodulator DAF-7/TGF-β. DAF-7, in turn, activates a canonical TGF-β signaling pathway in adjacent interneurons to modulate aerotaxis behavior and promote avoidance of pathogenic P. aeruginosa. Our data provide a chemical, genetic, and neuronal basis for how the behavior and physiology of a simple animal host can be modified by the microbial environment and suggest that secondary metabolites produced by microbes may provide environmental cues that contribute to pathogen recognition and host survival. PMID:25303524

  20. Bacterial chemoreceptors and chemoeffectors.

    Science.gov (United States)

    Bi, Shuangyu; Lai, Luhua

    2015-02-01

    Bacteria use chemotaxis signaling pathways to sense environmental changes. Escherichia coli chemotaxis system represents an ideal model that illustrates fundamental principles of biological signaling processes. Chemoreceptors are crucial signaling proteins that mediate taxis toward a wide range of chemoeffectors. Recently, in deep study of the biochemical and structural features of chemoreceptors, the organization of higher-order clusters in native cells, and the signal transduction mechanisms related to the on-off signal output provides us with general insights to understand how chemotaxis performs high sensitivity, precise adaptation, signal amplification, and wide dynamic range. Along with the increasing knowledge, bacterial chemoreceptors can be engineered to sense novel chemoeffectors, which has extensive applications in therapeutics and industry. Here we mainly review recent advances in the E. coli chemotaxis system involving structure and organization of chemoreceptors, discovery, design, and characterization of chemoeffectors, and signal recognition and transduction mechanisms. Possible strategies for changing the specificity of bacterial chemoreceptors to sense novel chemoeffectors are also discussed.

  1. A novel feature ranking algorithm for biometric recognition with PPG signals.

    Science.gov (United States)

    Reşit Kavsaoğlu, A; Polat, Kemal; Recep Bozkurt, M

    2014-06-01

    This study is intended for describing the application of the Photoplethysmography (PPG) signal and the time domain features acquired from its first and second derivatives for biometric identification. For this purpose, a sum of 40 features has been extracted and a feature-ranking algorithm is proposed. This proposed algorithm calculates the contribution of each feature to biometric recognition and collocates the features, the contribution of which is from great to small. While identifying the contribution of the features, the Euclidean distance and absolute distance formulas are used. The efficiency of the proposed algorithms is demonstrated by the results of the k-NN (k-nearest neighbor) classifier applications of the features. During application, each 15-period-PPG signal belonging to two different durations from each of the thirty healthy subjects were used with a PPG data acquisition card. The first PPG signals recorded from the subjects were evaluated as the 1st configuration; the PPG signals recorded later at a different time as the 2nd configuration and the combination of both were evaluated as the 3rd configuration. When the results were evaluated for the k-NN classifier model created along with the proposed algorithm, an identification of 90.44% for the 1st configuration, 94.44% for the 2nd configuration, and 87.22% for the 3rd configuration has successfully been attained. The obtained results showed that both the proposed algorithm and the biometric identification model based on this developed PPG signal are very promising for contactless recognizing the people with the proposed method.

  2. Pattern Recognition of Signals for the Fault-Slip Type of Rock Burst in Coal Mines

    Directory of Open Access Journals (Sweden)

    X. S. Liu

    2015-01-01

    Full Text Available The fault-slip type of rock burst is a major threat to the safety of coal mining, and effectively recognizing its signals patterns is the foundation for the early warning and prevention. At first, a mechanical model of the fault-slip was established and the mechanism of the rock burst induced by the fault-slip was revealed. Then, the patterns of the electromagnetic radiation, acoustic emission (AE, and microseismic signals in the fault-slip type of rock burst were proposed, in that before the rock burst occurs, the electromagnetic radiation intensity near the sliding surface increases rapidly, the AE energy rises exponentially, and the energy released by microseismic events experiences at least one peak and is close to the next peak. At last, in situ investigations were performed at number 1412 coal face in the Huafeng Mine, China. Results showed that the signals patterns proposed are in good agreement with the process of the fault-slip type of rock burst. The pattern recognition can provide a basis for the early warning and the implementation of relief measures of the fault-slip type of rock burst.

  3. Study of the vocal signal in the amplitude-time representation. Speech segmentation and recognition algorithms

    International Nuclear Information System (INIS)

    This dissertation exposes an acoustical and phonetical study of vocal signal. The complex pattern of the signal is segmented into simple sub-patterns and each one of these sub-patterns may be segmented again into another more simplest patterns with lower level. Application of pattern recognition techniques facilitates on one hand this segmentation and on the other hand the definition of the structural relations between the sub-patterns. Particularly, we have developed syntactic techniques in which the rewriting rules, context-sensitive, are controlled by predicates using parameters evaluated on the sub-patterns themselves. This allow to generalize a pure syntactic analysis by adding a semantic information. The system we expose, realizes pre-classification and a partial identification of the phonemes as also the accurate detection of each pitch period. The voice signal is analysed directly using the amplitude-time representation. This system has been implemented on a mini-computer and it works in the real time. (author)

  4. Sleep apnoea episodes recognition by a committee of ELM classifiers from ECG signal.

    Science.gov (United States)

    Sadr, Nadi; de Chazal, Philip; van Schaik, Andre; Breen, Paul

    2015-08-01

    This paper describes a system for the recognition of sleep apnoea episodes from ECG signals using a committee of extreme learning machine (ELM) classifiers. RR-interval parameters (heart rate variability) have been used as the identifying features as they are directly affected by sleep apnoea. The MIT PhysioNet Apnea-ECG database was used. A committee of five ELM classifiers has been employed to classify one-minute epochs of ECG into normal or apnoeic epochs. Our results show that the classification performance from the committee of networks was superior to the results of a single ELM classifier for fan-outs from 1 to 100. Classification performance reached a plateau at a fan-out of 10. The maximum accuracy was 82.5% with a sensitivity of 81.9% and a specificity of 82.8%. The results were comparable to other published research with the same input data. PMID:26738070

  5. Recognition of Acoustic Signals of Induction Motors with the Use of MSAF10 and Bayes Classfier

    Directory of Open Access Journals (Sweden)

    Glowacz A.

    2016-03-01

    Full Text Available Condition monitoring of deterioration in the metallurgical equipment is essential for faultless operation of the metallurgical processes. These processes use various metallurgical equipment, such as induction motors or industrial furnaces. These devices operate continuously. Correct diagnosis and early detection of incipient faults allow to avoid accidents and help reducing financial loss. This paper deals with monitoring of rotor electrical faults of induction motor. A technique of recognition of acoustic signals of induction motors is presented. Three states of induction motor were analyzed. Studies were carried out for methods of data processing: Method of Selection of Amplitudes of Frequencies (MSAF10 and Bayes classifier. Condition monitoring is helpful to protect induction motors and metallurgical equipment. Further researches will allow to analyze other metallurgical equipment.

  6. A Novel AT-Rich DNA Recognition Mechanism for Bacterial Xenogeneic Silencer MvaT.

    Directory of Open Access Journals (Sweden)

    Pengfei Ding

    2015-06-01

    Full Text Available Bacterial xenogeneic silencing proteins selectively bind to and silence expression from many AT rich regions of the chromosome. They serve as master regulators of horizontally acquired DNA, including a large number of virulence genes. To date, three distinct families of xenogeneic silencers have been identified: H-NS of Proteobacteria, Lsr2 of the Actinomycetes, and MvaT of Pseudomonas sp. Although H-NS and Lsr2 family proteins are structurally different, they all recognize the AT-rich DNA minor groove through a common AT-hook-like motif, which is absent in the MvaT family. Thus, the DNA binding mechanism of MvaT has not been determined. Here, we report the characteristics of DNA sequences targeted by MvaT with protein binding microarrays, which indicates that MvaT prefers binding flexible DNA sequences with multiple TpA steps. We demonstrate that there are clear differences in sequence preferences between MvaT and the other two xenogeneic silencer families. We also determined the structure of the DNA-binding domain of MvaT in complex with a high affinity DNA dodecamer using solution NMR. This is the first experimental structure of a xenogeneic silencer in complex with DNA, which reveals that MvaT recognizes the AT-rich DNA both through base readout by an "AT-pincer" motif inserted into the minor groove and through shape readout by multiple lysine side chains interacting with the DNA sugar-phosphate backbone. Mutations of key MvaT residues for DNA binding confirm their importance with both in vitro and in vivo assays. This novel DNA binding mode enables MvaT to better tolerate GC-base pair interruptions in the binding site and less prefer A tract DNA when compared to H-NS and Lsr2. Comparison of MvaT with other bacterial xenogeneic silencers provides a clear picture that nature has evolved unique solutions for different bacterial genera to distinguish foreign from self DNA.

  7. Comparative analysis of species-specific ligand recognition in Toll-like receptor 8 signaling: a hypothesis.

    Directory of Open Access Journals (Sweden)

    Rajiv Gandhi Govindaraj

    Full Text Available Toll-like receptors (TLRs play a central role in the innate immune response by recognizing conserved structural patterns in a variety of microbes. TLRs are classified into six families, of which TLR7 family members include TLR7, 8, and 9, which are localized to endolysosomal compartments recognizing viral infection in the form of foreign nucleic acids. In our current study, we focused on TLR8, which has been shown to recognize different types of ligands such as viral or bacterial ssRNA as well as small synthetic molecules. The primary sequences of rodent and non-rodent TLR8s are similar, but the antiviral compound (R848 that activates the TLR8 pathway is species-specific. Moreover, the factors underlying the receptor's species-specificity remain unknown. To this end, comparative homology modeling, molecular dynamics simulations refinement, automated docking and computational mutagenesis studies were employed to probe the intermolecular interactions between this anti-viral compound and TLR8. Furthermore, comparative analyses of modeled TLR8 (rodent and non-rodent structures have shown that the variation mainly occurs at LRR14-15 (undefined region; hence, we hypothesized that this variation may be the primary reason for the exhibited species-specificity. Our hypothesis was further bolstered by our docking studies, which clearly showed that this undefined region was in close proximity to the ligand-binding site and thus may play a key role in ligand recognition. In addition, the interface between the ligand and TLR8s varied depending upon the amino acid charges, free energy of binding, and interaction surface. Therefore, our current work provides a hypothesis for previous in vivo studies in the context of TLR signaling.

  8. Both piston-like and rotational motions are present in bacterial chemoreceptor signaling.

    Science.gov (United States)

    Yu, Daqi; Ma, Xiaomin; Tu, Yuhai; Lai, Luhua

    2015-01-01

    Bacterial chemotaxis signaling is triggered by binding of chemo-effectors to the membrane-bound chemoreceptor dimers. Though much is known about the structure of the chemoreceptors, details of the receptor dynamics and their effects on signaling are still unclear. Here, by using molecular dynamics simulations and principle component analysis, we study the dynamics of the periplasmic domain of aspartate chemoreceptor Tar dimer and its conformational changes when binding to different ligands (attractant, antagonist, and two attractant molecules). We found two dominant components (modes) in the receptor dynamics: a relative rotation of the two Tar monomers and a piston-like up-and-down sliding movement of the α4 helix. These two modes are highly correlated. Binding of one attractant molecule to the Tar dimer induced both significant piston-like downward movements of the α4 helix and strong relative rotations of the two Tar monomers, while binding of an antagonist or the symmetric binding of two attractant molecules to a Tar dimer suppresses both modes. The anti-symmetric effects of the relative rotation mode also explained the negative cooperativity between the two binding pockets. Our results suggest a mechanism of coupled rotation and piston-like motion for bacterial chemoreceptor signaling.

  9. Recognition of the Agrobacterium tumefaciens VirE2 translocation signal by the VirB/D4 transport system does not require VirE1.

    Science.gov (United States)

    Vergunst, Annette C; van Lier, Miranda C M; den Dulk-Ras, Amke; Hooykaas, Paul J J

    2003-11-01

    Agrobacterium tumefaciens uses a type IV secretion system to deliver a nucleoprotein complex and effector proteins directly into plant cells. The single-stranded DNA-binding protein VirE2, the F-box protein VirF and VirE3 are delivered into host cells via this VirB/D4 encoded translocation system. VirE1 functions as a chaperone of VirE2 by regulating its efficient translation and preventing VirE2-VirE2 aggregation in the bacterial cell. We analyzed whether the VirE1 chaperone is also essential for transport recognition of VirE2 by the VirB/D4 encoded type IV secretion system. In addition, we assayed whether translocation of VirF and VirE3, which also forms part of the virE operon, is affected by the absence of VirE1. We employed the earlier developed CRAFT (Cre recombinase Reporter Assay For Translocation) assay to detect transfer of Cre::Vir fusion proteins from A. tumefaciens into plants, monitored by stable reconstitution of a kanamycin resistance marker, and into yeast, screened by loss of the URA3 gene. We show that the C-terminal 50 amino acids of VirE2 and VirE3 are sufficient to mediate Cre translocation into host cells, confirming earlier indications of a C-terminal transport signal. This transfer was independent of the presence or absence of VirE1. Besides, the translocation efficiency of VirF is not altered in a virE1 mutant. The results unambiguously show that the VirE1 chaperone is not essential for the recognition of the VirE2 transport signal by the transport system and the subsequent translocation across the bacterial envelope into host cells. PMID:14551327

  10. Sound transmission and the recognition of temporally degraded sexual advertisement signals in Cope's gray treefrog (Hyla chrysoscelis)

    Science.gov (United States)

    Kuczynski, Michael C.; Vélez, Alejandro; Schwartz, Joshua J.; Bee, Mark A.

    2010-01-01

    Acoustic communication signals degrade as they propagate between signalers and receivers. While we generally understand the degrading effects of sound propagation on the structure of acoustic signals, we know considerably less about how receivers make behavioral decisions based on the perception of degraded signals in sonically and structurally complex habitats where communication occurs. In this study of acoustic mate recognition in Cope's gray treefrog, Hyla chrysoscelis (Cope 1880), we investigated how the temporal structure of male advertisement calls was compromised by propagation in a natural habitat and how females responded to stimuli mimicking various levels of temporal degradation. In a sound transmission experiment, we quantified changes in the pulsed structure of signals by broadcasting synthetic calls during active choruses from positions where we typically encountered signalers, and re-recording the signals from positions where we typically encountered potential receivers. Our main finding was that the silent gaps between pulses become increasingly ‘filled in’ by background noise and reverberations as a function of increasing propagation distance. We also conducted female phonotaxis experiments to determine the threshold modulation depth required to elicit recognition of the pulsatile structure of the call. Females were surprisingly tolerant of degraded temporal structure, and there was a tendency for greater permissiveness at lower playback levels. We discuss these results in terms of presumed mechanisms of call recognition in complex environments and the acoustic adaptation hypothesis. PMID:20675554

  11. T3_MM: A Markov Model Effectively Classifies Bacterial Type III Secretion Signals

    OpenAIRE

    Yejun Wang; Ming'an Sun; Hongxia Bao; Aaron P. White

    2013-01-01

    MOTIVATION: Type III Secretion Systems (T3SSs) play important roles in the interaction between gram-negative bacteria and their hosts. T3SSs function by translocating a group of bacterial effector proteins into the host cytoplasm. The details of specific type III secretion process are yet to be clarified. This research focused on comparing the amino acid composition within the N-terminal 100 amino acids from type III secretion (T3S) signal sequences or non-T3S proteins, specifically whether e...

  12. Branched signal wiring of an essential bacterial cell-cycle phosphotransfer protein

    OpenAIRE

    Blair, Jimmy A.; Xu, Qingping; Childers, W. Seth; Mathews, Irimpan I.; Kern, Justin W.; Eckart, Michael; Deacon, Ashley M.; Shapiro, Lucy

    2013-01-01

    Vital to bacterial survival is the faithful propagation of cellular signals, and in Caulobacter crescentus ChpT is an essential mediator within the cell cycle circuit. ChpT functions as a histidine-containing phosphotransfer protein (HPt) that shuttles a phosphoryl group from the receiver domain of CckA, the upstream hybrid histidine kinase (HK), to one of two downstream response regulators (RRs)—CtrA or CpdR—that controls cell cycle progression. To understand how ChpT interacts with multiple...

  13. Diamidinium and iminium aromatics as new aggregators of the bacterial signaling molecule, c-di-GMP.

    Science.gov (United States)

    Kelsey, Ilana; Nakayama, Shizuka; Sintim, Herman O

    2012-01-15

    C-di-GMP has emerged as an important bacterial signaling molecule that is involved in biofilm formation. Small molecules that can form biologically inactive complexes with c-di-GMP have the potential to be used as anti-biofilm agents. Herein, we report that water-soluble diamidinium/iminium aromatics (such as berenil), which are traditionally considered as minor groove binders of nucleic acids, are capable of aggregating c-di-GMP into G-quadruplexes via π-stacking interactions. PMID:22217869

  14. Translational arrest by a prokaryotic signal recognition particle is mediated by RNA interactions.

    Science.gov (United States)

    Beckert, Bertrand; Kedrov, Alexej; Sohmen, Daniel; Kempf, Georg; Wild, Klemens; Sinning, Irmgard; Stahlberg, Henning; Wilson, Daniel N; Beckmann, Roland

    2015-10-01

    The signal recognition particle (SRP) recognizes signal sequences of nascent polypeptides and targets ribosome-nascent chain complexes to membrane translocation sites. In eukaryotes, translating ribosomes are slowed down by the Alu domain of SRP to allow efficient targeting. In prokaryotes, however, little is known about the structure and function of Alu domain-containing SRPs. Here, we report a complete molecular model of SRP from the Gram-positive bacterium Bacillus subtilis, based on cryo-EM. The SRP comprises two subunits, 6S RNA and SRP54 or Ffh, and it facilitates elongation slowdown similarly to its eukaryotic counterpart. However, protein contacts with the small ribosomal subunit observed for the mammalian Alu domain are substituted in bacteria by RNA-RNA interactions of 6S RNA with the α-sarcin-ricin loop and helices H43 and H44 of 23S rRNA. Our findings provide a structural basis for cotranslational targeting and RNA-driven elongation arrest in prokaryotes. PMID:26344568

  15. Frequency study of facial electromyography signals with respect to emotion recognition.

    Science.gov (United States)

    Selvaraj, Jerritta; Murugappan, Murugappan; Wan, Khairunizam; Yaacob, Sazali

    2014-06-01

    Emotional intelligence is one of the key research areas in human-computer interaction. This paper reports the development of an emotion recognition system using facial electromyogram (EMG) signals focusing the ambiguity on the frequency ranges used by different research works. The six emotional states (happiness, sadness, fear, surprise, disgust, and neutral) were elicited in 60 subjects using audio visual stimuli. Statistical features were extracted from the signals at high, medium, low, and very low frequency levels. They were then classified using four classifiers - naïve Bayes, regression tree, K-nearest neighbor, and fuzzy K-nearest neighbor, and the performance of the system at the different frequency levels were studied using three metrics, namely, % accuracy, sensitivity, and specificity. The post hoc tests in analysis of variance (ANOVA) indicate that the features contain significant emotional information at the very low-frequency range (work indicate that it should not be ignored. Further investigation of the very low frequency range to identify emotional information is still in progress. PMID:24402883

  16. Is the C-terminal insertional signal in Gram-negative bacterial outer membrane proteins species-specific or not?

    Directory of Open Access Journals (Sweden)

    Paramasivam Nagarajan

    2012-09-01

    Full Text Available Abstract Background In Gram-negative bacteria, the outer membrane is composed of an asymmetric lipid bilayer of phopspholipids and lipopolysaccharides, and the transmembrane proteins that reside in this membrane are almost exclusively β-barrel proteins. These proteins are inserted into the membrane by a highly conserved and essential machinery, the BAM complex. It recognizes its substrates, unfolded outer membrane proteins (OMPs, through a C-terminal motif that has been speculated to be species-specific, based on theoretical and experimental results from only two species, Escherichia coli and Neisseria meningitidis, where it was shown on the basis of individual sequences and motifs that OMPs from the one cannot easily be over expressed in the other, unless the C-terminal motif was adapted. In order to determine whether this species specificity is a general phenomenon, we undertook a large-scale bioinformatics study on all predicted OMPs from 437 fully sequenced proteobacterial strains. Results We were able to verify the incompatibility reported between Escherichia coli and Neisseria meningitidis, using clustering techniques based on the pairwise Hellinger distance between sequence spaces for the C-terminal motifs of individual organisms. We noticed that the amino acid position reported to be responsible for this incompatibility between Escherichia coli and Neisseria meningitidis does not play a major role for determining species specificity of OMP recognition by the BAM complex. Instead, we found that the signal is more diffuse, and that for most organism pairs, the difference between the signals is hard to detect. Notable exceptions are the Neisseriales, and Helicobacter spp. For both of these organism groups, we describe the specific sequence requirements that are at the basis of the observed difference. Conclusions Based on the finding that the differences between the recognition motifs of almost all organisms are small, we assume that

  17. Bacterial Signal Transduction by Cyclic Di-GMP and Other Nucleotide Second Messengers.

    Science.gov (United States)

    Hengge, Regine; Gründling, Angelika; Jenal, Urs; Ryan, Robert; Yildiz, Fitnat

    2016-01-01

    The first International Symposium on c-Di-GMP Signaling in Bacteria (22 to 25 March 2015, Harnack-Haus, Berlin, Germany)brought together 131 molecular microbiologists from 17 countries to discuss recent progress in our knowledge of bacterial nucleotide second messenger signaling. While the focus was on signal input, synthesis, degradation, and the striking diversity of the modes of action of the current second messenger paradigm, i.e., cyclic di-GMP (c-di-GMP), “classics” like cAMP and (p)ppGpp were also presented, in novel facets, and more recent “newcomers,” such as c-di-AMP and c-AMP-GMP, made an impressive appearance. A number of clear trends emerged during the 30 talks, on the 71 posters, and in the lively discussions, including (i)c-di-GMP control of the activities of various ATPases and phosphorylation cascades, (ii) extensive cross talk between c-di-GMP and other nucleotide second messenger signaling pathways, and (iii) a stunning number of novel effectors for nucleotide second messengers that surprisingly include some long-known master regulators of developmental pathways. Overall, the conference made it amply clear that second messenger signaling is currently one of the most dynamic fields within molecular microbiology,with major impacts in research fields ranging from human health to microbial ecology. PMID:26055111

  18. Bacterial Signal Transduction by Cyclic Di-GMP and Other Nucleotide Second Messengers.

    Science.gov (United States)

    Hengge, Regine; Gründling, Angelika; Jenal, Urs; Ryan, Robert; Yildiz, Fitnat

    2016-01-01

    The first International Symposium on c-Di-GMP Signaling in Bacteria (22 to 25 March 2015, Harnack-Haus, Berlin, Germany)brought together 131 molecular microbiologists from 17 countries to discuss recent progress in our knowledge of bacterial nucleotide second messenger signaling. While the focus was on signal input, synthesis, degradation, and the striking diversity of the modes of action of the current second messenger paradigm, i.e., cyclic di-GMP (c-di-GMP), “classics” like cAMP and (p)ppGpp were also presented, in novel facets, and more recent “newcomers,” such as c-di-AMP and c-AMP-GMP, made an impressive appearance. A number of clear trends emerged during the 30 talks, on the 71 posters, and in the lively discussions, including (i)c-di-GMP control of the activities of various ATPases and phosphorylation cascades, (ii) extensive cross talk between c-di-GMP and other nucleotide second messenger signaling pathways, and (iii) a stunning number of novel effectors for nucleotide second messengers that surprisingly include some long-known master regulators of developmental pathways. Overall, the conference made it amply clear that second messenger signaling is currently one of the most dynamic fields within molecular microbiology,with major impacts in research fields ranging from human health to microbial ecology.

  19. Old concepts, new molecules and current approaches applied to the bacterial nucleotide signalling field

    Science.gov (United States)

    2016-01-01

    Signalling nucleotides are key molecules that help bacteria to rapidly coordinate cellular pathways and adapt to changes in their environment. During the past 10 years, the nucleotide signalling field has seen much excitement, as several new signalling nucleotides have been discovered in both eukaryotic and bacterial cells. The fields have since advanced quickly, aided by the development of important tools such as the synthesis of modified nucleotides, which, combined with sensitive mass spectrometry methods, allowed for the rapid identification of specific receptor proteins along with other novel genome-wide screening methods. In this review, we describe the principle concepts of nucleotide signalling networks and summarize the recent work that led to the discovery of the novel signalling nucleotides. We also highlight current approaches applied to the research in the field as well as resources and methodological advances aiding in a rapid identification of nucleotide-specific receptor proteins. This article is part of the themed issue ‘The new bacteriology’. PMID:27672152

  20. Recognition of the bacterial second messenger cyclic diguanylate by its cognate riboswitch

    Energy Technology Data Exchange (ETDEWEB)

    Kulshina, Nadia; Baird, Nathan J.; Ferré-D' Amaré, Adrian R.; (UWASH); (FHCRC)

    2009-12-03

    The cyclic diguanylate (bis-(3'-5')-cyclic dimeric guanosine monophosphate, c-di-GMP) riboswitch is the first known example of a gene-regulatory RNA that binds a second messenger. c-di-GMP is widely used by bacteria to regulate processes ranging from biofilm formation to the expression of virulence genes. The cocrystal structure of the c-di-GMP responsive GEMM riboswitch upstream of the tfoX gene of Vibrio cholerae reveals the second messenger binding the RNA at a three-helix junction. The two-fold symmetric second messenger is recognized asymmetrically by the monomeric riboswitch using canonical and noncanonical base-pairing as well as intercalation. These interactions explain how the RNA discriminates against cyclic diadenylate (c-di-AMP), a putative bacterial second messenger. Small-angle X-ray scattering and biochemical analyses indicate that the RNA undergoes compaction and large-scale structural rearrangement in response to ligand binding, consistent with organization of the core three-helix junction of the riboswitch concomitant with binding of c-di-GMP.

  1. Estradiol-Induced Object Recognition Memory Consolidation Is Dependent on Activation of mTOR Signaling in the Dorsal Hippocampus

    Science.gov (United States)

    Fortress, Ashley M.; Fan, Lu; Orr, Patrick T.; Zhao, Zaorui; Frick, Karyn M.

    2013-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is an important regulator of protein synthesis and is essential for various forms of hippocampal memory. Here, we asked whether the enhancement of object recognition memory consolidation produced by dorsal hippocampal infusion of 17[Beta]-estradiol (E[subscript 2]) is dependent on mTOR…

  2. Transmembrane Signaling Characterized in Bacterial Chemoreceptors by Using Sulfhydryl Cross-Linking in vivo

    Science.gov (United States)

    Lee, Geoffrey F.; Lebert, Michael R.; Lilly, Angela A.; Hazelbauer, Gerald L.

    1995-04-01

    Transmembrane signaling by bacterial chemoreceptors is thought to involve conformational changes within a stable homodimer. We investigated the functional consequences of constraining movement between pairs of helices in the four-helix structure of the transmembrane domain of chemoreceptor Trg. Using a family of cysteine-containing receptors, we identified oxidation treatments for intact cells that catalyzed essentially complete sulfhydryl cross-linking at selected positions and yet left flagellar and sensory functions largely unperturbed. Constraining movement by cross-links between subunits had little effect on tactic response, but constraining movement between transmembrane segments of the monomer drastically reduced function. We deduce that transmembrane signaling requires substantial movement between transmembrane helices of a monomer but not between interacting helices across the interface between subunits.

  3. Chemical Signals of Synthetic Disaccharide Derivatives Dominate Rhamnolipids at Controlling Multiple Bacterial Activities.

    Science.gov (United States)

    Singh, Nischal; Shetye, Gauri S; Zheng, Hewen; Sun, Jiayue; Luk, Yan-Yeung

    2016-01-01

    Microbes secrete molecules that modify their environment. Here, we demonstrate a class of synthetic disaccharide derivatives (DSDs) that mimics and dominates the activity of naturally secreted rhamnolipids by Pseudomonas aeruginosa. The DSDs exhibit the dual function of activating and inhibiting the swarming motility through a concentration-dependent activity reversal that is characteristic of signaling molecules. Whereas DSDs tethered with a saturated farnesyl group exhibit inhibition of both biofilm formation and swarming motility, with higher activities than rhamnolipids, a saturated farnesyl tethered with a sulfonate group only inhibits swarming motility but promote biofilm formation. These results identified important structural elements for controlling swarming motility, biofilm formation, and bacterial adhesion and suggest an effective chemical approach to control intertwined signaling processes that are important for biofilm formation and motilities. PMID:26511780

  4. Transmembrane helix dynamics of bacterial chemoreceptors supports a piston model of signalling.

    Directory of Open Access Journals (Sweden)

    Benjamin A Hall

    2011-10-01

    Full Text Available Transmembrane α-helices play a key role in many receptors, transmitting a signal from one side to the other of the lipid bilayer membrane. Bacterial chemoreceptors are one of the best studied such systems, with a wealth of biophysical and mutational data indicating a key role for the TM2 helix in signalling. In particular, aromatic (Trp and Tyr and basic (Arg residues help to lock α-helices into a membrane. Mutants in TM2 of E. coli Tar and related chemoreceptors involving these residues implicate changes in helix location and/or orientation in signalling. We have investigated the detailed structural basis of this via high throughput coarse-grained molecular dynamics (CG-MD of Tar TM2 and its mutants in lipid bilayers. We focus on the position (shift and orientation (tilt, rotation of TM2 relative to the bilayer and how these are perturbed in mutants relative to the wildtype. The simulations reveal a clear correlation between small (ca. 1.5 Å shift in position of TM2 along the bilayer normal and downstream changes in signalling activity. Weaker correlations are seen with helix tilt, and little/none between signalling and helix twist. This analysis of relatively subtle changes was only possible because the high throughput simulation method allowed us to run large (n = 100 ensembles for substantial numbers of different helix sequences, amounting to ca. 2000 simulations in total. Overall, this analysis supports a swinging-piston model of transmembrane signalling by Tar and related chemoreceptors.

  5. Signal recognition by frogs in the presence of temporally fluctuating chorus-shaped noise.

    Science.gov (United States)

    Vélez, Alejandro; Bee, Mark A

    2010-10-01

    The background noise generated in large social aggregations of calling individuals is a potent source of auditory masking for animals that communicate acoustically. Despite similarities with the so-called "cocktail-party problem" in humans, few studies have explicitly investigated how non-human animals solve the perceptual task of separating biologically relevant acoustic signals from ambient background noise. Under certain conditions, humans experience a release from auditory masking when speech is presented in speech-like masking noise that fluctuates in amplitude. We tested the hypothesis that females of Cope's gray treefrog (Hyla chrysoscelis) experience masking release in artificial chorus noise that fluctuates in level at modulations rates characteristic of those present in ambient chorus noise. We estimated thresholds for recognizing conspecific advertisement calls (pulse rate=40-50 pulses/s) in the presence of unmodulated and sinusoidally amplitude modulated (SAM) chorus-shaped masking noise. We tested two rates of modulation (5 Hz and 45 Hz) because the sounds of frog choruses are modulated at low rates (e.g., less than 5-10 Hz), and because those of species with pulsatile signals are additionally modulated at higher rates typical of the pulse rate of calls (e.g., between 15-50 Hz). Recognition thresholds were similar in the unmodulated and 5-Hz SAM conditions, and 12 dB higher in the 45-Hz SAM condition. These results did not support the hypothesis that female gray treefrogs experience masking release in temporally fluctuating chorus-shaped noise. We discuss our results in terms of modulation masking, and hypothesize that natural amplitude fluctuations in ambient chorus noise may impair mating call perception.

  6. Enter at your own risk: how enteroviruses navigate the dangerous world of pattern recognition receptor signaling.

    Science.gov (United States)

    Harris, Katharine G; Coyne, Carolyn B

    2013-09-01

    Enteroviruses are the most common human viral pathogens worldwide. This genus of small, non-enveloped, single stranded RNA viruses includes coxsackievirus, rhinovirus, echovirus, and poliovirus species. Infection with these viruses can induce mild symptoms that resemble the common cold, but can also be associated with more severe syndromes such as poliomyelitis, neurological diseases including aseptic meningitis and encephalitis, myocarditis, and the onset of type I diabetes. In humans, polarized epithelial cells lining the respiratory and/or digestive tracts represent the initial sites of infection by enteroviruses. Control of infection in the host is initiated through the engagement of a variety of pattern recognition receptors (PRRs). PRRs act as the sentinels of the innate immune system and serve to alert the host to the presence of a viral invader. This review assembles the available data annotating the role of PRRs in the response to enteroviral infection as well as the myriad ways by which enteroviruses both interrupt and manipulate PRR signaling to enhance their own replication, thereby inducing human disease. PMID:23764548

  7. A PP2A-B55 recognition signal controls substrate dephosphorylation kinetics during mitotic exit.

    Science.gov (United States)

    Cundell, Michael J; Hutter, Lukas H; Nunes Bastos, Ricardo; Poser, Elena; Holder, James; Mohammed, Shabaz; Novak, Bela; Barr, Francis A

    2016-08-29

    PP2A-B55 is one of the major phosphatases regulating cell division. Despite its importance for temporal control during mitotic exit, how B55 substrates are recognized and differentially dephosphorylated is unclear. Using phosphoproteomics combined with kinetic modeling to extract B55-dependent rate constants, we have systematically identified B55 substrates and assigned their temporal order in mitotic exit. These substrates share a bipartite polybasic recognition determinant (BPR) flanking a Cdk1 phosphorylation site. Experiments and modeling show that dephosphorylation rate is encoded into B55 substrates, including its inhibitor ENSA, by cooperative action of basic residues within the BPR. A complementary acidic surface on B55 decodes this signal, supporting a cooperative electrostatic mechanism for substrate selection. A further level of specificity is encoded into B55 substrates because B55 displays selectivity for phosphothreonine. These simple biochemical properties, combined with feedback control of B55 activity by the phosphoserine-containing substrate/inhibitor ENSA, can help explain the temporal sequence of events during exit from mitosis. PMID:27551054

  8. Signal recognition particle immunoglobulin g detected incidentally associates with autoimmune myopathy

    Science.gov (United States)

    Apiwattanakul, Metha; Milone, Margherita; Pittock, Sean J.; Kryzer, Thomas J.; Fryer, James P.; O'toole, Orna; Mckeon, Andrew

    2016-01-01

    ABSTRACT Introduction: Paraneoplastic autoantibody screening of 150,000 patient sera by tissue‐based immunofluorescence incidentally revealed 170 with unsuspected signal recognition particle (SRP) immunoglobulin G (IgG), which is a recognized biomarker of autoimmune myopathy. Of the 77 patients with available information, 54 had myopathy. We describe the clinical/laboratory associations. Methods: Distinctive cytoplasm‐binding IgG (mouse tissue substrate) prompted western blot, enzyme‐linked immunoassay, and immunoprecipitation analyses. Available histories were reviewed. Results: The immunostaining pattern resembled rough endoplasmic reticulum, and mimicked Purkinje‐cell cytoplasmic antibody type 1 IgG/anti‐Yo. Immunoblotting revealed ribonucleoprotein reactivity. Recombinant antigens confirmed the following: SRP54 IgG specificity alone (17); SRP72 IgG specificity alone (3); both (32); or neither (2). Coexisting neural autoantibodies were identified in 28% (low titer). Electromyography revealed myopathy with fibrillation potentials; 78% of biopsies had active necrotizing myopathy with minimal inflammation, and 17% had inflammatory myopathy. Immunotherapy responsiveness was typically slow and incomplete, and relapses were frequent on withdrawal. Histologically confirmed cancers (17%) were primarily breast and hematologic, with some others. Conclusions: Autoimmune necrotizing SRP myopathy, both idiopathic and paraneoplastic, is underdiagnosed in neurological practice. Serological screening aids early diagnosis. Cancer surveillance and appropriate immunosuppressant therapy may improve outcome. Muscle Nerve 53: 925–932, 2016 PMID:26561982

  9. Structural basis of a rationally rewired protein-protein interface critical to bacterial signaling.

    Science.gov (United States)

    Podgornaia, Anna I; Casino, Patricia; Marina, Alberto; Laub, Michael T

    2013-09-01

    Two-component signal transduction systems typically involve a sensor histidine kinase that specifically phosphorylates a single, cognate response regulator. This protein-protein interaction relies on molecular recognition via a small set of residues in each protein. To better understand how these residues determine the specificity of kinase-substrate interactions, we rationally rewired the interaction interface of a Thermotoga maritima two-component system, HK853-RR468, to match that found in a different two-component system, Escherichia coli PhoR-PhoB. The rewired proteins interacted robustly with each other, but no longer interacted with the parent proteins. Analysis of the crystal structures of the wild-type and mutant protein complexes and a systematic mutagenesis study reveal how individual mutations contribute to the rewiring of interaction specificity. Our approach and conclusions have implications for studies of other protein-protein interactions and protein evolution and for the design of novel protein interfaces. PMID:23954504

  10. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  11. NOD1 and NOD2 receptors in mrigal (Cirrhinus mrigala): Inductive expression and downstream signalling in ligand stimulation and bacterial infections

    Indian Academy of Sciences (India)

    Banikalyan Swain; Madhubanti Basu; Mrinal Samanta

    2013-09-01

    Nucleotide binding and oligomerization domain (NOD)1 and NOD2 are important cytoplasmic pattern recognition receptors (PRRs) and key members of the NOD-like receptor (NLR) family. They sense a wide range of bacteria or their products and play a key role in inducing innate immunity. This report describes the role of NOD1 and NOD2 receptors signalling in innate immunity in the Indian major carp, mrigal (Cirrhinus mrigala). Tissue-specific expression analysis of NOD1 and NOD2 genes by quantitative real-time PCR (qRT-PCR) revealed their wide distribution in various organs/tissues. In the untreated fish, the highest expression of NOD1 and NOD2 was detected in liver and blood, respectively. Stimulation with NOD1- and NOD2-specific ligands, i.e. iE-DAP and MDP, activated NOD1 and NOD2 receptor signalling in vivo and in vitro resulting in significant ( < 0.05) induction of downstream signalling molecule RICK, and the effector molecules IL-1, IL-8 and IFN- in the treated group as compared to their controls. In response to both Gram-positive and Gram-negative bacterial infections, NOD1 and NOD2 receptors signalling were activated and IL-1, IL-8 and IFN- were induced. These findings highlight the important role of NOD receptors in eliciting innate immune response during the pathogenic invasion to the fish.

  12. A conserved juxtacrine signal regulates synaptic partner recognition in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Mock Natalyn

    2011-06-01

    beyond wild-type levels. Furthermore, an artificially membrane-tethered UNC-6 expressed in the postsynaptic neurons promotes SPR, consistent with a short-range signal between adjacent synaptic partners. Conclusions These results indicate that the conserved UNC-6/Netrin-UNC-40/DCC ligand-receptor pair has a previously unknown function, acting in a juxtacrine manner to specify recognition of individual postsynaptic neurons. Furthermore, they illustrate the potential of this new approach, combining NLG-1 GRASP and behavioral analysis, in gene discovery and characterization.

  13. Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation.

    Science.gov (United States)

    Chaudhari, Snehal N; Mukherjee, Madhumati; Vagasi, Alexandra S; Bi, Gaofeng; Rahman, Mohammad M; Nguyen, Christine Q; Paul, Ligi; Selhub, Jacob; Kipreos, Edward T

    2016-07-11

    Here we describe an in vitro primary culture system for Caenorhabditis elegans germline stem cells. This culture system was used to identify a bacterial folate as a positive regulator of germ cell proliferation. Folates are a family of B-complex vitamins that function in one-carbon metabolism to allow the de novo synthesis of amino acids and nucleosides. We show that germ cell proliferation is stimulated by the folate 10-formyl-tetrahydrofolate-Glun both in vitro and in animals. Other folates that can act as vitamins to rescue folate deficiency lack this germ cell stimulatory activity. The bacterial folate precursor dihydropteroate also promotes germ cell proliferation in vitro and in vivo, despite its inability to promote one-carbon metabolism. The folate receptor homolog FOLR-1 is required for the stimulation of germ cells by 10-formyl-tetrahydrofolate-Glun and dihydropteroate. This work defines a folate and folate-related compound as exogenous signals to modulate germ cell proliferation. PMID:27404357

  14. Architecture and signal transduction mechanism of the bacterial chemosensory array: progress, controversies, and challenges.

    Science.gov (United States)

    Falke, Joseph J; Piasta, Kene N

    2014-12-01

    Recent research has deepened our understanding of the ancient, conserved chemosensory array that detects small molecule attractants and repellents, and directs the chemotaxis of bacterial and archaeal cells towards an optimal chemical environment. Here we review advances towards a molecular description of the ultrastable lattice architecture and ultrasensitive signal transduction mechanism of the chemosensory array, as well as controversies and challenges requiring further research. Ultimately, a full molecular understanding of array structure and on-off switching will foster (i) the design of novel therapies that block pathogenic wound seeking and infection, (ii) the development of highly specific, sensitive, stable biosensors, and (iii) the elucidation of general functional principles shared by receptor patches in all branches of life.

  15. Homeostatic interplay between bacterial cell-cell signaling and iron in virulence.

    Directory of Open Access Journals (Sweden)

    Ronen Hazan

    2010-03-01

    Full Text Available Pathogenic bacteria use interconnected multi-layered regulatory networks, such as quorum sensing (QS networks to sense and respond to environmental cues and external and internal bacterial cell signals, and thereby adapt to and exploit target hosts. Despite the many advances that have been made in understanding QS regulation, little is known regarding how these inputs are integrated and processed in the context of multi-layered QS regulatory networks. Here we report the examination of the Pseudomonas aeruginosa QS 4-hydroxy-2-alkylquinolines (HAQs MvfR regulatory network and determination of its interaction with the QS acyl-homoserine-lactone (AHL RhlR network. The aim of this work was to elucidate paradigmatically the complex relationships between multi-layered regulatory QS circuitries, their signaling molecules, and the environmental cues to which they respond. Our findings revealed positive and negative homeostatic regulatory loops that fine-tune the MvfR regulon via a multi-layered dependent homeostatic regulation of the cell-cell signaling molecules PQS and HHQ, and interplay between these molecules and iron. We discovered that the MvfR regulon component PqsE is a key mediator in orchestrating this homeostatic regulation, and in establishing a connection to the QS rhlR system in cooperation with RhlR. Our results show that P. aeruginosa modulates the intensity of its virulence response, at least in part, through this multi-layered interplay. Our findings underscore the importance of the homeostatic interplay that balances competition within and between QS systems via cell-cell signaling molecules and environmental cues in the control of virulence gene expression. Elucidation of the fine-tuning of this complex relationship offers novel insights into the regulation of these systems and may inform strategies designed to limit infections caused by P. aeruginosa and related human pathogens.

  16. The HopQ1 effector's nucleoside hydrolase-like domain is required for bacterial virulence in arabidopsis and tomato, but not host recognition in tobacco.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Bacterial pathogens deliver multiple effector proteins into host cells to facilitate bacterial growth. HopQ1 is an effector from Pseudomonas syringae pv. tomato DC3000 that is conserved across multiple bacterial pathogens which infect plants. HopQ1's central region possesses some homology to nucleoside hydrolases, but possesses an alternative aspartate motif not found in characterized enzymes. A structural model was generated for HopQ1 based on the E. coli RihB nucleoside hydrolase and the role of HopQ1's potential catalytic residues for promoting bacterial virulence and recognition in Nicotiana tabacum was investigated. Transgenic Arabidopsis plants expressing HopQ1 exhibit enhanced disease susceptibility to DC3000. HopQ1 can also promote bacterial virulence on tomato when naturally delivered from DC3000. HopQ1's nucleoside hydrolase-like domain alone is sufficient to promote bacterial virulence, and putative catalytic residues are required for virulence promotion during bacterial infection of tomato and in transgenic Arabidopsis lines. HopQ1 is recognized and elicits cell death when transiently expressed in N. tabacum. Residues required to promote bacterial virulence were dispensable for HopQ1's cell death promoting activities in N. tabacum. Although HopQ1 has some homology to nucleoside hydrolases, we were unable to detect HopQ1 enzymatic activity or nucleoside binding capability using standard substrates. Thus, it is likely that HopQ1 promotes pathogen virulence by hydrolyzing alternative ribose-containing substrates in planta.

  17. A Novel Method for Recognition of Bioradiolocation Signal Breathing Patterns for Noncontact Screening of Sleep Apnea Syndrome

    OpenAIRE

    Maksim Alekhin; Lesya Anishchenko; Alexander Tataraidze; Sergey Ivashov; Vladimir Parashin; Lyudmila Korostovtseva; Yurii Sviryaev; Alexey Bogomolov

    2013-01-01

    A novel method for recognition of breathing patterns of bioradiolocation signals breathing patterns (BSBP) in the task of noncontact screening of sleep apnea syndrome (SAS) is proposed and implemented on the base of wavelet transform (WT) and neural network (NNW) applications. Selection of the optimal parameters of WT includes determination of the proper level of wavelet decomposition and the best basis for feature extraction using modified entropy criterion. Selection of the optimal properti...

  18. A NUFFT Based Step-frequency Chirp Signal High Resolution Imaging Algorithm and Target Recognition Algorithm

    Directory of Open Access Journals (Sweden)

    Xiang Yin

    2015-12-01

    Full Text Available Radar Automatic Target Recognition (RATR is the key technique to be breaked through in the fuure development of intelligent weapon system. Compared to the 2-D SAR image target recognition, High Resolution Range Profile (HRRP target recognition has the advantage of low data dimension, low requirement of radar system's calculation and storage ability, and the imaging algorithm is also not complicated. HRRP imaging is the first and the key process in target recognition, its speed and imaging quality can directly influence the real-time capability and accuracy of target recognition. In this paper a new HRRP imaging algorithm — NUFFT algorithm is proposed, the derivation of mathematical expression is given, both for the echo simulation process and the imaging process. In the meantime, by analyzing each step's calculation complexity, we compared the calculation complexity of four different imaging algorithms, we also simulate two target's imaging and target recognition processing. Theoretical analysis and simulation both prove that the proposed algorithm's calculation complexity is improved in various degree compared with the others, thus can be effectively used in target recognition.

  19. Diagnostics of separately excited DC motor based on analysis and recognition of signals using FFT and Bayes classifier

    Directory of Open Access Journals (Sweden)

    Glowacz Witold

    2015-03-01

    Full Text Available In this article results of diagnostic investigations of separately excited DC motor were presented. In diagnostics were applied a Fourier analysis method based on the fast Fourier transform (FFT and a recognition method using Bayes classifier. In training process a set of the most important frequencies has been determined for which differences of corresponding signals in two states are the largest. Three categories of signals have been recognized in identification process: faultless state, state of the rotor broken one coil and state of the rotor shorted three coils.

  20. Analysis of chemical signals in red fire ants by gas chromatography and pattern recognition techniques

    Science.gov (United States)

    The combination of gas chromatography and pattern recognition (GC/PR) analysis is a powerful tool for investigating complicated biological problems. Clustering, mapping, discriminant development, etc. are necessary to analyze realistically large chromatographic data sets and to seek meaningful relat...

  1. Molecular insight into the role of the N-terminal extension in the maturation, substrate recognition, and catalysis of a bacterial alginate lyase from polysaccharide lyase family 18.

    Science.gov (United States)

    Dong, Sheng; Wei, Tian-Di; Chen, Xiu-Lan; Li, Chun-Yang; Wang, Peng; Xie, Bin-Bin; Qin, Qi-Long; Zhang, Xi-Ying; Pang, Xiu-Hua; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2014-10-24

    Bacterial alginate lyases, which are members of several polysaccharide lyase (PL) families, have important biological roles and biotechnological applications. The mechanisms for maturation, substrate recognition, and catalysis of PL18 alginate lyases are still largely unknown. A PL18 alginate lyase, aly-SJ02, from Pseudoalteromonas sp. 0524 displays a β-jelly roll scaffold. Structural and biochemical analyses indicated that the N-terminal extension in the aly-SJ02 precursor may act as an intramolecular chaperone to mediate the correct folding of the catalytic domain. Molecular dynamics simulations and mutational assays suggested that the lid loops over the aly-SJ02 active center serve as a gate for substrate entry. Molecular docking and site-directed mutations revealed that certain conserved residues at the active center, especially those at subsites +1 and +2, are crucial for substrate recognition. Tyr(353) may function as both a catalytic base and acid. Based on our results, a model for the catalysis of aly-SJ02 in alginate depolymerization is proposed. Moreover, although bacterial alginate lyases from families PL5, 7, 15, and 18 adopt distinct scaffolds, they share the same conformation of catalytic residues, reflecting their convergent evolution. Our results provide the foremost insight into the mechanisms of maturation, substrate recognition, and catalysis of a PL18 alginate lyase.

  2. Recognition Memory zROC Slopes for Items with Correct versus Incorrect Source Decisions Discriminate the Dual Process and Unequal Variance Signal Detection Models

    Science.gov (United States)

    Starns, Jeffrey J.; Rotello, Caren M.; Hautus, Michael J.

    2014-01-01

    We tested the dual process and unequal variance signal detection models by jointly modeling recognition and source confidence ratings. The 2 approaches make unique predictions for the slope of the recognition memory zROC function for items with correct versus incorrect source decisions. The standard bivariate Gaussian version of the unequal…

  3. Signal recognition by green treefrogs (Hyla cinerea) and Cope's gray treefrogs (Hyla chrysoscelis) in naturally fluctuating noise.

    Science.gov (United States)

    Vélez, Alejandro; Bee, Mark A

    2013-05-01

    This study tested three hypotheses about the ability of female frogs to exploit temporal fluctuations in the level of background noise to overcome the problem of recognizing male advertisement calls in noisy breeding choruses. Phonotaxis tests with green treefrogs (Hyla cinerea) and Cope's gray treefrogs (Hyla chrysoscelis) were used to measure thresholds for recognizing calls in the presence of noise maskers with (a) no level fluctuations, (b) random fluctuations, or level fluctuations characteristic of (c) conspecific choruses and (d) heterospecific choruses. The dip-listening hypothesis predicted lower signal recognition thresholds in the presence of fluctuating maskers compared with nonfluctuating maskers. Support for the dip-listening hypothesis was weak; only Cope's gray treefrogs experienced dip listening and only in the presence of randomly fluctuating maskers. The natural soundscapes advantage hypothesis predicted lower recognition thresholds when level fluctuations resembled those of natural soundscapes compared with artificial fluctuations. This hypothesis was rejected. In noise backgrounds with natural fluctuations, the species-specific advantage hypothesis predicted lower recognition thresholds when fluctuations resembled species-specific patterns of conspecific soundscapes. No evidence was found to support this hypothesis. These results corroborate previous findings showing that Cope's gray treefrogs, but not green treefrogs, experience dip listening under some noise conditions. Together, the results suggest level fluctuations in the soundscape of natural breeding choruses may present few dip-listening opportunities. The findings of this study provide little support for the hypothesis that receivers are adapted to exploit level fluctuations of natural soundscapes in recognizing communication signals.

  4. Recognition of purified beta 1,3/1,6 glucan and molecular signalling in the intestine of Atlantic salmon.

    Science.gov (United States)

    Kiron, Viswanath; Kulkarni, Amod; Dahle, Dalia; Vasanth, Ghana; Lokesh, Jep; Elvebo, Odd

    2016-03-01

    Atlantic salmon was orally intubated with a highly purified β-glucan product (MacroGard(®)) to study the recognition of the molecule by the receptor genes, the regulation of the downstream signalling genes and global proteins, and the micromorphological changes in the intestine. The β-glucan receptor genes of Atlantic salmon, sclra, sclrb, sclrc and cr3, seem to recognize the molecule, and initiate the downstream ITAM-motif signalling, as evident from the significantly high mRNA levels of ksyk, mapkin2, il1b and mip2a levels. Among the altered proteins, the Apoa4 (involved in carbohydrate and lipid metabolism); Tagln, Actb (uptake of β-glucan); Psma2 (associated with substrate recognition); and Ckt (energy metabolism-related) were the overexpressed ones. The underexpressed proteins included the Uk114, Rpl9, Ctsb and Lgal that are connected to proliferation, LPS-stimulation, Il1b and lactose recognition, respectively. Furthermore, the mRNA levels of igt and the number of immune cells in the distal intestine were found to increase upon β-glucan uptake by the fish. This study provides some clues on the mechanisms by which the β-glucan evokes response in Atlantic salmon, particularly at the intestinal level.

  5. Direct sensing and signal transduction during bacterial chemotaxis toward aromatic compounds in Comamonas testosteroni.

    Science.gov (United States)

    Huang, Zhou; Ni, Bin; Jiang, Cheng-Ying; Wu, Yu-Fan; He, Yun-Zhe; Parales, Rebecca E; Liu, Shuang-Jiang

    2016-07-01

    Micro-organisms sense and chemotactically respond to aromatic compounds. Although the existence of chemoreceptors that bind to aromatic attractants and subsequently trigger chemotaxis have long been speculated, such a chemoreceptor has not been demonstrated. In this report, we demonstrated that the chemoreceptor MCP2901 from Comamonas testosteroni CNB-1 binds to aromatic compounds and initiates downstream chemotactic signaling in addition to its ability to trigger chemotaxis via citrate binding. The function of gene MCP2901 was investigated by genetic deletion from CNB-1 and genetic complementation of the methyl-accepting chemotaxis protein (MCP)-null mutant CNB-1Δ20. Results showed that the expression of MCP2901 in the MCP-null mutant restored chemotaxis toward nine tested aromatic compounds and nine carboxylic acids. Isothermal titration calorimetry (ITC) analyses demonstrated that the ligand-binding domain of MCP2901 (MCP2901LBD) bound to citrate, and weakly to gentisate and 4-hydroxybenzoate. Additionally, ITC assays indicated that MCP2901LBD bound strongly to 2,6-dihydroxybenzoate and 2-hydroxybenzoate, which are isomers of gentisate and 4-hydroxybenzoate respectively that are not metabolized by CNB-1. Agarose-in-plug and capillary assays showed that these two molecules serve as chemoattractants for CNB-1. Through constructing membrane-like MCP2901-inserted Nanodiscs and phosphorelay activity assays, we demonstrated that 2,6-dihydroxybenzoate and 2-hydroxybenzoate altered kinase activity of CheA. This is the first evidence of an MCP binding to an aromatic molecule and triggering signal transduction for bacterial chemotaxis.

  6. Autonomic nervous system dynamics for mood and emotional-state recognition significant advances in data acquisition, signal processing and classification

    CERN Document Server

    Valenza, Gaetano

    2014-01-01

    This monograph reports on advances in the measurement and study of autonomic nervous system (ANS) dynamics as a source of reliable and effective markers for mood state recognition and assessment of emotional responses. Its primary impact will be in affective computing and the application of emotion-recognition systems. Applicative studies of biosignals such as: electrocardiograms; electrodermal responses; respiration activity; gaze points; and pupil-size variation are covered in detail, and experimental results explain how to characterize the elicited affective levels and mood states pragmatically and accurately using the information thus extracted from the ANS. Nonlinear signal processing techniques play a crucial role in understanding the ANS physiology underlying superficially noticeable changes and provide important quantifiers of cardiovascular control dynamics. These have prognostic value in both healthy subjects and patients with mood disorders. Moreover, Autonomic Nervous System Dynamics for Mood and ...

  7. The Bacterial Transcription Termination Factor Rho Coordinates Mg(2+) Homeostasis with Translational Signals.

    Science.gov (United States)

    Kriner, Michelle A; Groisman, Eduardo A

    2015-12-01

    The bacterial protein Rho triggers transcription termination at the ends of many operons and when transcription and translation become uncoupled. In addition to these genome wide activities, Rho implements regulation of specific genes by dictating whether RNA polymerase terminates transcription within the 5' leader region or continues into the downstream coding region. Here, we report that the Mg(2+) channel gene corA in Salmonella enterica serovar Typhimurium, which was previously thought to be constitutively expressed, is regulated by a Rho-dependent terminator located within its 5' leader region. We demonstrate that the unusually long and highly conserved corA leader mRNA can adopt two mutually exclusive conformations that determine whether or not Rho interacts with a Rho utilization site on the nascent RNA and thereby prevents transcription of the corA coding region. The RNA conformation that promotes Rho-dependent termination is favored by efficient translation of corL, a short open reading frame located within the corA leader. Thus, corA transcription is inversely coupled to corL translation. This mechanism resembles those governing expression of Salmonella's other two Mg(2+) transport genes, suggesting that Rho links Mg(2+) uptake to translational signals. PMID:26523680

  8. Caenorhabditis elegans recognizes a bacterial quorum-sensing signal molecule through the AWCON neuron.

    Science.gov (United States)

    Werner, Kristen M; Perez, Lark J; Ghosh, Rajarshi; Semmelhack, Martin F; Bassler, Bonnie L

    2014-09-19

    In a process known as quorum sensing, bacteria use chemicals called autoinducers for cell-cell communication. Population-wide detection of autoinducers enables bacteria to orchestrate collective behaviors. In the animal kingdom detection of chemicals is vital for success in locating food, finding hosts, and avoiding predators. This behavior, termed chemotaxis, is especially well studied in the nematode Caenorhabditis elegans. Here we demonstrate that the Vibrio cholerae autoinducer (S)-3-hydroxytridecan-4-one, termed CAI-1, influences chemotaxis in C. elegans. C. elegans prefers V. cholerae that produces CAI-1 over a V. cholerae mutant defective for CAI-1 production. The position of the CAI-1 ketone moiety is the key feature driving CAI-1-directed nematode behavior. CAI-1 is detected by the C. elegans amphid sensory neuron AWC(ON). Laser ablation of the AWC(ON) cell, but not other amphid sensory neurons, abolished chemoattraction to CAI-1. These analyses define the structural features of a bacterial-produced signal and the nematode chemosensory neuron that permit cross-kingdom interaction.

  9. Low-shear modeled microgravity: a global environmental regulatory signal affecting bacterial gene expression, physiology, and pathogenesis

    Science.gov (United States)

    Nickerson, Cheryl A.; Ott, C. Mark; Wilson, James W.; Ramamurthy, Rajee; LeBlanc, Carly L.; Honer zu Bentrup, Kerstin; Hammond, Timothy; Pierson, Duane L.

    2003-01-01

    Bacteria inhabit an impressive variety of ecological niches and must adapt constantly to changing environmental conditions. While numerous environmental signals have been examined for their effect on bacteria, the effects of mechanical forces such as shear stress and gravity have only been investigated to a limited extent. However, several important studies have demonstrated a key role for the environmental signals of low shear and/or microgravity in the regulation of bacterial gene expression, physiology, and pathogenesis [Chem. Rec. 1 (2001) 333; Appl. Microbiol. Biotechnol. 54 (2000) 33; Appl. Environ. Microbiol. 63 (1997) 4090; J. Ind. Microbiol. 18 (1997) 22; Curr. Microbiol. 34(4) (1997) 199; Appl. Microbiol. Biotechnol. 56(3-4) (2001) 384; Infect Immun. 68(6) (2000) 3147; Cell 109(7) (2002) 913; Appl. Environ. Microbiol. 68(11) (2002) 5408; Proc. Natl. Acad. Sci. U. S. A. 99(21) (2002) 13807]. The response of bacteria to these environmental signals, which are similar to those encountered during prokaryotic life cycles, may provide insight into bacterial adaptations to physiologically relevant conditions. This review focuses on the current and potential future research trends aimed at understanding the effect of the mechanical forces of low shear and microgravity analogues on different bacterial parameters. In addition, this review also discusses the use of microgravity technology to generate physiologically relevant human tissue models for research in bacterial pathogenesis.

  10. Emotional recognition from the speech signal for a virtual education agent

    Science.gov (United States)

    Tickle, A.; Raghu, S.; Elshaw, M.

    2013-06-01

    This paper explores the extraction of features from the speech wave to perform intelligent emotion recognition. A feature extract tool (openSmile) was used to obtain a baseline set of 998 acoustic features from a set of emotional speech recordings from a microphone. The initial features were reduced to the most important ones so recognition of emotions using a supervised neural network could be performed. Given that the future use of virtual education agents lies with making the agents more interactive, developing agents with the capability to recognise and adapt to the emotional state of humans is an important step.

  11. The Picture Superiority Effect in Recognition Memory: A Developmental Study Using the Response Signal Procedure

    Science.gov (United States)

    Defeyter, Margaret Anne; Russo, Riccardo; McPartlin, Pamela Louise

    2009-01-01

    Items studied as pictures are better remembered than items studied as words even when test items are presented as words. The present study examined the development of this picture superiority effect in recognition memory. Four groups ranging in age from 7 to 20 years participated. They studied words and pictures, with test stimuli always presented…

  12. Using Errors by Guard Honeybees (Apis mellifera) to Gain New Insights into Nestmate Recognition Signals.

    Science.gov (United States)

    Pradella, Duccio; Martin, Stephen J; Dani, Francesca R

    2015-11-01

    Although the honeybee (Apis mellifera) is one of the world most studied insects, the chemical compounds used in nestmate recognition, remains an open question. By exploiting the error prone recognition system of the honeybee, coupled with genotyping, we studied the correlation between cuticular hydrocarbon (CHC) profile of returning foragers and acceptance or rejection behavior by guards. We revealed an average recognition error rate of 14% across 3 study colonies, that is, allowing a non-nestmate colony entry, or preventing a nestmate from entry, which is lower than reported in previous studies. By analyzing CHCs, we found that CHC profile of returning foragers correlates with acceptance or rejection by guarding bees. Although several CHC were identified as potential recognition cues, only a subset of 4 differed consistently for their relative amount between accepted and rejected individuals in the 3 studied colonies. These include a unique group of 2 positional alkene isomers (Z-8 and Z-10), which are almost exclusively produced by the bees Bombus and Apis spp, and may be candidate compounds for further study. PMID:26385960

  13. Linking ligand perception by PEPR pattern recognition receptors to cytosolic Ca2+ elevation and downstream immune signaling in plants.

    Science.gov (United States)

    Ma, Yi; Walker, Robin K; Zhao, Yichen; Berkowitz, Gerald A

    2012-11-27

    Little is known about molecular steps linking perception of pathogen invasion by cell surface sentry proteins acting as pattern recognition receptors (PRRs) to downstream cytosolic Ca(2+) elevation, a critical step in plant immune signaling cascades. Some PRRs recognize molecules (such as flagellin) associated with microbial pathogens (pathogen-associated molecular patterns, PAMPs), whereas others bind endogenous plant compounds (damage-associated molecular patterns, DAMPs) such as peptides released from cells upon attack. This work focuses on the Arabidopsis DAMPs plant elicitor peptides (Peps) and their receptors, PEPR1 and PEPR2. Pep application causes in vivo cGMP generation and downstream signaling that is lost when the predicted PEPR receptor guanylyl cyclase (GC) active site is mutated. Pep-induced Ca(2+) elevation is attributable to cGMP activation of a Ca(2+) channel. Some differences were identified between Pep/PEPR signaling and the Ca(2+)-dependent immune signaling initiated by the flagellin peptide flg22 and its cognate receptor Flagellin-sensing 2 (FLS2). FLS2 signaling may have a greater requirement for intracellular Ca(2+) stores and inositol phosphate signaling, whereas Pep/PEPR signaling requires extracellular Ca(2+). Maximal FLS2 signaling requires a functional Pep/PEPR system. This dependence was evidenced as a requirement for functional PEPR receptors for maximal flg22-dependent Ca(2+) elevation, H(2)O(2) generation, defense gene [WRKY33 and Plant Defensin 1.2 (PDF1.2)] expression, and flg22/FLS2-dependent impairment of pathogen growth. In a corresponding fashion, FLS2 loss of function impaired Pep signaling. In addition, a role for PAMP and DAMP perception in bolstering effector-triggered immunity (ETI) is reported; loss of function of either FLS2 or PEPR receptors impaired the hypersensitive response (HR) to an avirulent pathogen.

  14. Get rich quick: the signal to respond procedure reveals the time course of semantic richness effects during visual word recognition.

    Science.gov (United States)

    Hargreaves, Ian S; Pexman, Penny M

    2014-05-01

    According to several current frameworks, semantic processing involves an early influence of language-based information followed by later influences of object-based information (e.g., situated simulations; Santos, Chaigneau, Simmons, & Barsalou, 2011). In the present study we examined whether these predictions extend to the influence of semantic variables in visual word recognition. We investigated the time course of semantic richness effects in visual word recognition using a signal-to-respond (STR) paradigm fitted to a lexical decision (LDT) and a semantic categorization (SCT) task. We used linear mixed effects to examine the relative contributions of language-based (number of senses, ARC) and object-based (imageability, number of features, body-object interaction ratings) descriptions of semantic richness at four STR durations (75, 100, 200, and 400ms). Results showed an early influence of number of senses and ARC in the SCT. In both LDT and SCT, object-based effects were the last to influence participants' decision latencies. We interpret our results within a framework in which semantic processes are available to influence word recognition as a function of their availability over time, and of their relevance to task-specific demands.

  15. A census of membrane-bound and intracellular signal transduction proteins in bacteria: Bacterial IQ, extroverts and introverts

    Directory of Open Access Journals (Sweden)

    Galperin Michael Y

    2005-06-01

    Full Text Available Abstract Background Analysis of complete microbial genomes showed that intracellular parasites and other microorganisms that inhabit stable ecological niches encode relatively primitive signaling systems, whereas environmental microorganisms typically have sophisticated systems of environmental sensing and signal transduction. Results This paper presents results of a comprehensive census of signal transduction proteins – histidine kinases, methyl-accepting chemotaxis receptors, Ser/Thr/Tyr protein kinases, adenylate and diguanylate cyclases and c-di-GMP phosphodiesterases – encoded in 167 bacterial and archaeal genomes, sequenced by the end of 2004. The data have been manually checked to avoid false-negative and false-positive hits that commonly arise during large-scale automated analyses and compared against other available resources. The census data show uneven distribution of most signaling proteins among bacterial and archaeal phyla. The total number of signal transduction proteins grows approximately as a square of genome size. While histidine kinases are found in representatives of all phyla and are distributed according to the power law, other signal transducers are abundant in certain phylogenetic groups but virtually absent in others. Conclusion The complexity of signaling systems differs even among closely related organisms. Still, it usually can be correlated with the phylogenetic position of the organism, its lifestyle, and typical environmental challenges it encounters. The number of encoded signal transducers (or their fraction in the total protein set can be used as a measure of the organism's ability to adapt to diverse conditions, the 'bacterial IQ', while the ratio of transmembrane receptors to intracellular sensors can be used to define whether the organism is an 'extrovert', actively sensing the environmental parameters, or an 'introvert', more concerned about its internal homeostasis. Some of the microorganisms with the

  16. Lipid motif of a bacterial antigen mediates immune responses via TLR2 signaling.

    Directory of Open Access Journals (Sweden)

    Amit A Lugade

    Full Text Available The cross-talk between the innate and the adaptive immune system is facilitated by the initial interaction of antigen with dendritic cells. As DCs express a large array of TLRs, evidence has accumulated that engagement of these molecules contributes to the activation of adaptive immunity. We have evaluated the immunostimulatory role of the highly-conserved outer membrane lipoprotein P6 from non-typeable Haemophilus influenzae (NTHI to determine whether the presence of the lipid motif plays a critical role on its immunogenicity. We undertook a systematic analysis of the role that the lipid motif plays in the activation of DCs and the subsequent stimulation of antigen-specific T and B cells. To facilitate our studies, recombinant P6 protein that lacked the lipid motif was generated. Mice immunized with non-lipidated rP6 were unable to elicit high titers of anti-P6 Ig. Expression of the lipid motif on P6 was also required for proliferation and cytokine secretion by antigen-specific T cells. Upregulation of T cell costimulatory molecules was abrogated in DCs exposed to non-lipidated rP6 and in TLR2(-/- DCs exposed to native P6, thereby resulting in diminished adaptive immune responses. Absence of either the lipid motif on the antigen or TLR2 expression resulted in diminished cytokine production from stimulated DCs. Collectively, our data suggest that the lipid motif of the lipoprotein antigen is essential for triggering TLR2 signaling and effective stimulation of APCs. Our studies establish the pivotal role of a bacterial lipid motif on activating both innate and adaptive immune responses to an otherwise poorly immunogenic protein antigen.

  17. Steroid hormone signaling is essential to regulate innate immune cells and fight bacterial infection in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jennifer C Regan

    2013-10-01

    Full Text Available Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. Drosophila metamorphosis represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, nothing is known about the mechanisms that coordinate development and immune cell activity in the transition from larva to adult. Here, we reveal that regulation of macrophage-like cells (hemocytes by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. Although it is generally accepted that steroid hormones impact immunity in mammals, their action on monocytes (e.g. macrophages and neutrophils is still not well understood. Here in a simpler model system, we used an approach that allows in vivo, cell autonomous analysis of hormonal regulation of innate immune cells, by combining genetic manipulation with flow cytometry, high-resolution time-lapse imaging and tissue-specific transcriptomic analysis. We show that in response to ecdysone, hemocytes rapidly upregulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic and local production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential for hemocyte immune functions and survival after infection. Microarray analysis of hemocytes revealed a large set of genes regulated at metamorphosis by EcR signaling, among which many are known to function in cell motility, cell shape or phagocytosis. This study demonstrates an important role for steroid hormone regulation of

  18. IMMUNE RBF NETWORK AND ITS APPLICATION IN THE MODULATION-STYLE RECOGNITION OF RADAR SIGNALS

    Institute of Scientific and Technical Information of China (English)

    Gong Xinbao; Zang Xiaogang; Zhou Xilang; Hu Guangrui

    2003-01-01

    Based on Immune Programming(IP), a novel Radial Basis Function (RBF) networkdesigning method is proposed. Through extracting the preliminary knowledge about the widthof the basis function as the vaccine to form the immune operator, the algorithm reduces thesearching space of canonical algorithm and improves the convergence speed. The application ofthe RBF network trained with the algorithm in the modulation-style recognition of radar signalsdemonstrates that the network has a fast convergence speed with good performances.

  19. Mechanisms of phosphatidylserine exposure, a phagocyte recognition signal, on apoptotic T lymphocytes

    OpenAIRE

    1995-01-01

    The appearance of phosphatidylserine (PS) on the cell surface during apoptosis in thymocytes and cytotoxic T lymphocyte cell lines provokes PS-dependent recognition by activated macrophages. Flow cytometric analysis of transbilayer lipid movements in T lymphocytes undergoing apoptosis reveals that downregulation of the adenosine triphosphate- dependent amino-phospholipid translocase and activation of a nonspecific lipid scramblase are responsible for PS reaching the surface from its intracell...

  20. Effects of cue modality and emotional category on recognition of nonverbal emotional signals in schizophrenia

    OpenAIRE

    Vogel, Bastian D.; Brück, Carolin; Jacob, Heike; Eberle, Mark; Wildgruber, Dirk

    2016-01-01

    Background Impaired interpretation of nonverbal emotional cues in patients with schizophrenia has been reported in several studies and a clinical relevance of these deficits for social functioning has been assumed. However, it is unclear to what extent the impairments depend on specific emotions or specific channels of nonverbal communication. Methods Here, the effect of cue modality and emotional categories on accuracy of emotion recognition was evaluated in 21 patients with schizophrenia an...

  1. Primary Stability Recognition of the Newly Designed Cementless Femoral Stem Using Digital Signal Processing

    Science.gov (United States)

    Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A.; Abdul Majid, Norazman

    2014-01-01

    Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing. PMID:24800230

  2. Primary stability recognition of the newly designed cementless femoral stem using digital signal processing.

    Science.gov (United States)

    Baharuddin, Mohd Yusof; Salleh, Sh-Hussain; Hamedi, Mahyar; Zulkifly, Ahmad Hafiz; Lee, Muhammad Hisyam; Mohd Noor, Alias; Harris, Arief Ruhullah A; Abdul Majid, Norazman

    2014-01-01

    Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA) is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM) to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing. PMID:24800230

  3. Primary Stability Recognition of the Newly Designed Cementless Femoral Stem Using Digital Signal Processing

    Directory of Open Access Journals (Sweden)

    Mohd Yusof Baharuddin

    2014-01-01

    Full Text Available Stress shielding and micromotion are two major issues which determine the success of newly designed cementless femoral stems. The correlation of experimental validation with finite element analysis (FEA is commonly used to evaluate the stress distribution and fixation stability of the stem within the femoral canal. This paper focused on the applications of feature extraction and pattern recognition using support vector machine (SVM to determine the primary stability of the implant. We measured strain with triaxial rosette at the metaphyseal region and micromotion with linear variable direct transducer proximally and distally using composite femora. The root mean squares technique is used to feed the classifier which provides maximum likelihood estimation of amplitude, and radial basis function is used as the kernel parameter which mapped the datasets into separable hyperplanes. The results showed 100% pattern recognition accuracy using SVM for both strain and micromotion. This indicates that DSP could be applied in determining the femoral stem primary stability with high pattern recognition accuracy in biomechanical testing.

  4. How plants sense wounds: damaged-self recognition is based on plant-derived elicitors and induces octadecanoid signaling.

    Directory of Open Access Journals (Sweden)

    Martin Heil

    Full Text Available BACKGROUND: Animal-derived elicitors can be used by plants to detect herbivory but they function only in specific insect-plant interactions. How can plants generally perceive damage caused by herbivores? Damaged-self recognition occurs when plants perceive molecular signals of damage: degraded plant molecules or molecules localized outside their original compartment. METHODOLOGY/PRINCIPAL FINDINGS: Flame wounding or applying leaf extract or solutions of sucrose or ATP to slightly wounded lima bean (Phaseolus lunatus leaves induced the secretion of extrafloral nectar, an indirect defense mechanism. Chemically related molecules that would not be released in high concentrations from damaged plant cells (glucose, fructose, salt, and sorbitol did not elicit a detectable response, excluding osmotic shock as an alternative explanation. Treatments inducing extrafloral nectar secretion also enhanced endogenous concentrations of the defense hormone jasmonic acid (JA. Endogenous JA was also induced by mechanically damaging leaves of lima bean, Arabidopsis, maize, strawberry, sesame and tomato. In lima bean, tomato and sesame, the application of leaf extract further increased endogenous JA content, indicating that damaged-self recognition is taxonomically widely distributed. Transcriptomic patterns obtained with untargeted 454 pyrosequencing of lima bean in response to flame wounding or the application of leaf extract or JA were highly similar to each other, but differed from the response to mere mechanical damage. We conclude that the amount or concentration of damaged-self signals can quantitatively determine the intensity of the wound response and that the full damaged-self response requires the disruption of many cells. CONCLUSIONS/SIGNIFICANCE: Numerous compounds function as JA-inducing elicitors in different plant species. Most of them are, contain, or release, plant-derived molecular motifs. Damaged-self recognition represents a taxonomically

  5. Dissecting the specificity of protein-protein interaction in bacterial two-component signaling: orphans and crosstalks.

    Directory of Open Access Journals (Sweden)

    Andrea Procaccini

    Full Text Available Predictive understanding of the myriads of signal transduction pathways in a cell is an outstanding challenge of systems biology. Such pathways are primarily mediated by specific but transient protein-protein interactions, which are difficult to study experimentally. In this study, we dissect the specificity of protein-protein interactions governing two-component signaling (TCS systems ubiquitously used in bacteria. Exploiting the large number of sequenced bacterial genomes and an operon structure which packages many pairs of interacting TCS proteins together, we developed a computational approach to extract a molecular interaction code capturing the preferences of a small but critical number of directly interacting residue pairs. This code is found to reflect physical interaction mechanisms, with the strongest signal coming from charged amino acids. It is used to predict the specificity of TCS interaction: Our results compare favorably to most available experimental results, including the prediction of 7 (out of 8 known interaction partners of orphan signaling proteins in Caulobacter crescentus. Surveying among the available bacterial genomes, our results suggest 15∼25% of the TCS proteins could participate in out-of-operon "crosstalks". Additionally, we predict clusters of crosstalking candidates, expanding from the anecdotally known examples in model organisms. The tools and results presented here can be used to guide experimental studies towards a system-level understanding of two-component signaling.

  6. Striatal intrinsic reinforcement signals during recognition memory: relationship to response bias and dysregulation in schizophrenia.

    Science.gov (United States)

    Wolf, Daniel H; Gerraty, Raphaelt; Satterthwaite, Theodore D; Loughead, James; Campellone, Timothy; Elliott, Mark A; Turetsky, Bruce I; Gur, Ruben C; Gur, Raquel E

    2011-01-01

    Ventral striatum (VS) is a critical brain region for reinforcement learning and motivation, and VS hypofunction is implicated in psychiatric disorders including schizophrenia. Providing rewards or performance feedback has been shown to activate VS. Intrinsically motivated subjects performing challenging cognitive tasks are likely to engage reinforcement circuitry even in the absence of external feedback or incentives. However, such intrinsic reinforcement responses have received little attention, have not been examined in relation to behavioral performance, and have not been evaluated for impairment in neuropsychiatric disorders such as schizophrenia. Here we used fMRI to examine a challenging "old" vs. "new" visual recognition task in healthy subjects and patients with schizophrenia. Targets were unique fractal stimuli previously presented as salient distractors in a visual oddball task, producing incidental memory encoding. Based on the prediction error theory of reinforcement learning, we hypothesized that correct target recognition would activate VS in controls, and that this activation would be greater in subjects with lower expectation of responding correctly as indexed by a more conservative response bias. We also predicted these effects would be reduced in patients with schizophrenia. Consistent with these predictions, controls activated VS and other reinforcement processing regions during correct recognition, with greater VS activation in those with a more conservative response bias. Patients did not show either effect, with significant group differences suggesting hyporesponsivity in patients to internally generated feedback. These findings highlight the importance of accounting for intrinsic motivation and reward when studying cognitive tasks, and add to growing evidence of reward circuit dysfunction in schizophrenia that may impact cognition and function.

  7. Striatal intrinsic reinforcement signals during recognition memory: relationship to response bias and dysregulation in schizophrenia

    Directory of Open Access Journals (Sweden)

    Daniel H Wolf

    2011-12-01

    Full Text Available Ventral striatum (VS is a critical brain region for reinforcement learning and motivation, and VS hypofunction is implicated in psychiatric disorders including schizophrenia. Providing rewards or performance feedback has been shown to activate VS. Intrinisically motivated subjects performing challenging cognitive tasks are likely to engage reinforcement circuitry even in the absence of external feedback or incentives. However, such intrinsic reinforcement responses have received little attention, have not been examined in relation to behavioral performance, and have not been evaluated for impairment in neuropsychiatric disorders such as schizophrenia. Here we used fMRI to examine a challenging 'old' vs. 'new' visual recognition task in healthy subjects and patients with schizophrenia. Targets were unique fractal stimuli previously presented as salient distractors in a visual oddball task, producing incidental memory encoding. Based on the prediction error theory of reinforcement learning, we hypothesized that correct target recognition would activate VS in controls, and that this activation would be greater in subjects with lower expectation of responding correctly as indexed by a more conservative response bias. We also predicted these effects would be reduced in patients with schizophrenia. Consistent with these predictions, controls activated VS and other reinforcement processing regions during correct recognition, with greater VS activation in those with a more conservative response bias. Patients did not show either effect, with significant group differences suggesting hyporesponsivity in patients to internally-generated feedback. These findings highlight the importance of accounting for intrinsic motivation and reward when studying cognitive tasks, and add to growing evidence of reward circuit dysfunction in schizophrenia that may impact cognition and function.

  8. Structural and functional studies of MinD ATPase: implications for the molecular recognition of the bacterial cell division apparatus

    OpenAIRE

    Hayashi, Ikuko; Oyama, Takuji; Morikawa, Kosuke

    2001-01-01

    Proper placement of the bacterial cell division site requires the site-specific inactivation of other potential division sites. In Escherichia coli, selection of the correct mid-cell site is mediated by the MinC, MinD and MinE proteins. To clarify the functional role of the bacterial cell division inhibitor MinD, which is a membrane-associated ATPase that works as an activator of MinC, we determined the crystal structure of a Pyrococcus furiosus MinD homologue complexed with a substrate analo...

  9. Tracking body and hands for gesture recognition: NATOPS aircraft handling signals database

    OpenAIRE

    Song, Yale; Demirdjian, David; Davis, Randall

    2011-01-01

    We present a unified framework for body and hand tracking, the output of which can be used for understanding simultaneously performed body-and-hand gestures. The framework uses a stereo camera to collect 3D images, and tracks body and hand together, combining various existing techniques to make tracking tasks efficient. In addition, we introduce a multi-signal gesture database: the NATOPS aircraft handling signals. Unlike previous gesture databases, this data requires knowledge about both bod...

  10. Signal recognition efficiencies of artificial neural-network pulse-shape discrimination in HPGe 0νββ-decay searches

    Energy Technology Data Exchange (ETDEWEB)

    Caldwell, A.; Cossavella, F.; Majorovits, B.; Palioselitis, D.; Volynets, O. [Max-Planck-Institut fuer Physik, Munich (Germany)

    2015-07-15

    A pulse-shape discrimination method based on artificial neural networks was applied to pulses simulated for different background, signal and signal-like interactions inside a germanium detector. The simulated pulses were used to investigate variations of efficiencies as a function of used training set. It is verified that neural networks are well-suited to identify background pulses in true-coaxial high-purity germanium detectors. The systematic uncertainty on the signal recognition efficiency derived using signal-like evaluation samples from calibration measurements is estimated to be 5 %. This uncertainty is due to differences between signal and calibration samples. (orig.)

  11. Not sensitive, yet less biased: A signal detection theory perspective on mindfulness, attention, and recognition memory.

    Science.gov (United States)

    Rosenstreich, Eyal; Ruderman, Lital

    2016-07-01

    The practice of mindfulness has been argued to increase attention control and improve memory performance. However, it was recently suggested that the effect of mindfulness on memory may be due to a shift in response-bias, rather than to an increase in memory-sensitivity. The present study examined the mindfulness-attention-memory triad. Participants filled in the five-facets of mindfulness questionnaire, and completed two recognition blocks; in the first attention was full, whereas in the second attention was divided during the encoding of information. It was found that the facet of non-judging (NJ) moderated the impact of attention on memory, such that responses of high NJ participants were less biased and remained constant even when attention was divided. Facets of mindfulness were not associated with memory sensitivity. These findings suggest that mindfulness may affect memory through decision making processes, rather than through directing attentional resources to the encoding of information. PMID:27236356

  12. Pattern Recognition of Signals for the Fault-Slip Type of Rock Burst in Coal Mines

    OpenAIRE

    Liu, X.S.; Tan, J; Y. L. Tan; Hu, S C

    2015-01-01

    The fault-slip type of rock burst is a major threat to the safety of coal mining, and effectively recognizing its signals patterns is the foundation for the early warning and prevention. At first, a mechanical model of the fault-slip was established and the mechanism of the rock burst induced by the fault-slip was revealed. Then, the patterns of the electromagnetic radiation, acoustic emission (AE), and microseismic signals in the fault-slip type of rock burst were proposed, in that before th...

  13. Pattern recognition applied to seismic signals of Llaima volcano (Chile): An evaluation of station-dependent classifiers

    Science.gov (United States)

    Curilem, Millaray; Huenupan, Fernando; Beltrán, Daniel; San Martin, Cesar; Fuentealba, Gustavo; Franco, Luis; Cardona, Carlos; Acuña, Gonzalo; Chacón, Max; Khan, M. Salman; Becerra Yoma, Nestor

    2016-04-01

    Automatic pattern recognition applied to seismic signals from volcanoes may assist seismic monitoring by reducing the workload of analysts, allowing them to focus on more challenging activities, such as producing reports, implementing models, and understanding volcanic behaviour. In a previous work, we proposed a structure for automatic classification of seismic events in Llaima volcano, one of the most active volcanoes in the Southern Andes, located in the Araucanía Region of Chile. A database of events taken from three monitoring stations on the volcano was used to create a classification structure, independent of which station provided the signal. The database included three types of volcanic events: tremor, long period, and volcano-tectonic and a contrast group which contains other types of seismic signals. In the present work, we maintain the same classification scheme, but we consider separately the stations information in order to assess whether the complementary information provided by different stations improves the performance of the classifier in recognising seismic patterns. This paper proposes two strategies for combining the information from the stations: i) combining the features extracted from the signals from each station and ii) combining the classifiers of each station. In the first case, the features extracted from the signals from each station are combined forming the input for a single classification structure. In the second, a decision stage combines the results of the classifiers for each station to give a unique output. The results confirm that the station-dependent strategies that combine the features and the classifiers from several stations improves the classification performance, and that the combination of the features provides the best performance. The results show an average improvement of 9% in the classification accuracy when compared with the station-independent method.

  14. Hepatitis B virus polymerase blocks pattern recognition receptor signaling via interaction with DDX3: implications for immune evasion.

    Directory of Open Access Journals (Sweden)

    Haifeng Wang

    Full Text Available Viral infection leads to induction of pattern-recognition receptor signaling, which leads to interferon regulatory factor (IRF activation and ultimately interferon (IFN production. To establish infection, many viruses have strategies to evade the innate immunity. For the hepatitis B virus (HBV, which causes chronic infection in the liver, the evasion strategy remains uncertain. We now show that HBV polymerase (Pol blocks IRF signaling, indicating that HBV Pol is the viral molecule that effectively counteracts host innate immune response. In particular, HBV Pol inhibits TANK-binding kinase 1 (TBK1/IkappaB kinase-epsilon (IKKepsilon, the effector kinases of IRF signaling. Intriguingly, HBV Pol inhibits TBK1/IKKepsilon activity by disrupting the interaction between IKKepsilon and DDX3 DEAD box RNA helicase, which was recently shown to augment TBK1/IKKepsilon activity. This unexpected role of HBV Pol may explain how HBV evades innate immune response in the early phase of the infection. A therapeutic implication of this work is that a strategy to interfere with the HBV Pol-DDX3 interaction might lead to the resolution of life-long persistent infection.

  15. The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots.

    Directory of Open Access Journals (Sweden)

    Nicholas Holton

    2015-01-01

    Full Text Available During plant immunity, surface-localized pattern recognition receptors (PRRs recognize pathogen-associated molecular patterns (PAMPs. The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs EFR and XA21 from Arabidopsis thaliana (Arabidopsis and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots.

  16. How to detect a cuckoo egg : A signal-detection theory model for recognition and learning

    NARCIS (Netherlands)

    Rodriguez-Girones, MA; Lotem, A

    1999-01-01

    This article presents a model of egg rejection in cases of brood parasitism. The model is developed in three stages in the framework of signal-detection theory. We first assume that the behavior of host females is adapted to the relevant parameters concerning the appearance of the eggs they lay. In

  17. ST2 negatively regulates TLR2 signaling, but is not required for bacterial lipoprotein-induced tolerance.

    LENUS (Irish Health Repository)

    Liu, Jinghua

    2010-05-15

    Activation of TLR signaling is critical for host innate immunity against bacterial infection. Previous studies reported that the ST2 receptor, a member of the Toll\\/IL-1 receptor superfamily, functions as a negative regulator of TLR4 signaling and maintains LPS tolerance. However, it is undetermined whether ST2 negatively regulates TLR2 signaling and furthermore, whether a TLR2 agonist, bacterial lipoprotein (BLP)-induced tolerance is dependent on ST2. In this study, we show that BLP stimulation-induced production of proinflammatory cytokines and immunocomplex formation of TLR2-MyD88 and MyD88-IL-1R-associated kinase (IRAK) were significantly enhanced in ST2-deficient macrophages compared with those in wild-type controls. Furthermore, overexpression of ST2 dose-dependently attenuated BLP-induced NF-kappaB activation, suggesting a negative regulatory role of ST2 in TLR2 signaling. A moderate but significantly attenuated production of TNF-alpha and IL-6 on a second BLP stimulation was observed in BLP-pretreated, ST2-deficient macrophages, which is associated with substantially reduced IRAK-1 protein expression and downregulated TLR2-MyD88 and MyD88-IRAK immunocomplex formation. ST2-deficient mice, when pretreated with a nonlethal dose of BLP, benefitted from an improved survival against a subsequent lethal BLP challenge, indicating BLP tolerance develops in the absence of the ST2 receptor. Taken together, our results demonstrate that ST2 acts as a negative regulator of TLR2 signaling, but is not required for BLP-induced tolerance.

  18. Arrhythmia recognition and classification using combined linear and nonlinear features of ECG signals.

    Science.gov (United States)

    Elhaj, Fatin A; Salim, Naomie; Harris, Arief R; Swee, Tan Tian; Ahmed, Taqwa

    2016-04-01

    Arrhythmia is a cardiac condition caused by abnormal electrical activity of the heart, and an electrocardiogram (ECG) is the non-invasive method used to detect arrhythmias or heart abnormalities. Due to the presence of noise, the non-stationary nature of the ECG signal (i.e. the changing morphology of the ECG signal with respect to time) and the irregularity of the heartbeat, physicians face difficulties in the diagnosis of arrhythmias. The computer-aided analysis of ECG results assists physicians to detect cardiovascular diseases. The development of many existing arrhythmia systems has depended on the findings from linear experiments on ECG data which achieve high performance on noise-free data. However, nonlinear experiments characterize the ECG signal more effectively sense, extract hidden information in the ECG signal, and achieve good performance under noisy conditions. This paper investigates the representation ability of linear and nonlinear features and proposes a combination of such features in order to improve the classification of ECG data. In this study, five types of beat classes of arrhythmia as recommended by the Association for Advancement of Medical Instrumentation are analyzed: non-ectopic beats (N), supra-ventricular ectopic beats (S), ventricular ectopic beats (V), fusion beats (F) and unclassifiable and paced beats (U). The characterization ability of nonlinear features such as high order statistics and cumulants and nonlinear feature reduction methods such as independent component analysis are combined with linear features, namely, the principal component analysis of discrete wavelet transform coefficients. The features are tested for their ability to differentiate different classes of data using different classifiers, namely, the support vector machine and neural network methods with tenfold cross-validation. Our proposed method is able to classify the N, S, V, F and U arrhythmia classes with high accuracy (98.91%) using a combined support

  19. Recognition- and Reactivity-Based Fluorescent Probes for Studying Transition Metal Signaling in Living Systems

    OpenAIRE

    Aron, Allegra T.; Ramos-Torres, Karla M.; Cotruvo, Joseph A.; Chang, Christopher J.

    2015-01-01

    Conspectus Metals are essential for life, playing critical roles in all aspects of the central dogma of biology (e.g., the transcription and translation of nucleic acids and synthesis of proteins). Redox-inactive alkali, alkaline earth, and transition metals such as sodium, potassium, calcium, and zinc are widely recognized as dynamic signals, whereas redox-active transition metals such as copper and iron are traditionally thought of as sequestered by protein ligands, including as static enzy...

  20. Physical activities recognition from ambulatory ECG signals using neuro-fuzzy classifiers and support vector machines.

    Science.gov (United States)

    Kher, Rahul; Pawar, Tanmay; Thakar, Vishvjit; Shah, Hitesh

    2015-02-01

    The use of wearable recorders for long-term monitoring of physiological parameters has increased in the last few years. The ambulatory electrocardiogram (A-ECG) signals of five healthy subjects with four body movements or physical activities (PA)-left arm up down, right arm up down, waist twisting and walking-have been recorded using a wearable ECG recorder. The classification of these four PAs has been performed using neuro-fuzzy classifier (NFC) and support vector machines (SVM). The PA classification is based on the distinct, time-frequency features of the extracted motion artifacts contained in recorded A-ECG signals. The motion artifacts in A-ECG signals have been separated first by the discrete wavelet transform (DWT) and the time-frequency features of these motion artifacts have then been extracted using the Gabor transform. The Gabor energy feature vectors have been fed to the NFC and SVM classifiers. Both the classifiers have achieved a PA classification accuracy of over 95% for all subjects. PMID:25641014

  1. A Simple Decision Rule for Recognition of Poly(A) Tail Signal Motifs in Human Genome

    KAUST Repository

    Eisha, Hassan Abou

    2015-05-12

    Background is the numerous attempts were made to predict motifs in genomic sequences that correspond to poly (A) tail signals. Vast portion of this effort has been directed to a plethora of nonlinear classification methods. Even when such approaches yield good discriminant results, identifying dominant features of regulatory mechanisms nevertheless remains a challenge. In this work, we look at decision rules that may help identifying such features. Findings are we present a simple decision rule for classification of candidate poly (A) tail signal motifs in human genomic sequence obtained by evaluating features during the construction of gradient boosted trees. We found that values of a single feature based on the frequency of adenine in the genomic sequence surrounding candidate signal and the number of consecutive adenine molecules in a well-defined region immediately following the motif displays good discriminative potential in classification of poly (A) tail motifs for samples covered by the rule. Conclusions is the resulting simple rule can be used as an efficient filter in construction of more complex poly(A) tail motifs classification algorithms.

  2. A novel human-machine interface based on recognition of multi-channel facial bioelectric signals

    International Nuclear Information System (INIS)

    Full text: This paper presents a novel human-machine interface for disabled people to interact with assistive systems for a better quality of life. It is based on multichannel forehead bioelectric signals acquired by placing three pairs of electrodes (physical channels) on the Fron-tails and Temporalis facial muscles. The acquired signals are passes through a parallel filter bank to explore three different sub-bands related to facial electromyogram, electrooculogram and electroencephalogram. The root mean features of the bioelectric signals analyzed within non-overlapping 256 ms windows were extracted. The subtractive fuzzy c-means clustering method (SFCM) was applied to segment the feature space and generate initial fuzzy based Takagi-Sugeno rules. Then, an adaptive neuro-fuzzy inference system is exploited to tune up the premises and consequence parameters of the extracted SFCMs. rules. The average classifier discriminating ratio for eight different facial gestures (smiling, frowning, pulling up left/right lips corner, eye movement to left/right/up/down is between 93.04% and 96.99% according to different combinations and fusions of logical features. Experimental results show that the proposed interface has a high degree of accuracy and robustness for discrimination of 8 fundamental facial gestures. Some potential and further capabilities of our approach in human-machine interfaces are also discussed. (author)

  3. Studies on the Conformational Features of Neomycin-B and its Molecular Recognition by RNA and Bacterial Defense Proteins

    Science.gov (United States)

    Asensio, Juan Luis; Bastida, Agatha; Jiménez-Barbero, Jesús

    According to NMR and molecular dynamics simulations, the conformational behavior of natural aminoglycosides is characterized by a remarkable flexibility, with different conformations, even non-exo-anomeric ones, in fast exchange. Very probably, this feature allows the adaptation of these ligands to the spatial and electronic requirements of different receptors. The large diversity of structures adopted by aminoglycosides in the binding pocket of the different RNA receptors and the distinct enzymes involved in bacterial resistance are consistent with this view. This conformational diversity can, in certain favorable cases, be exploited in the design of new antibiotic derivatives not susceptible to enzymatic inactivation, by designing tailor-made conformationally locked aminoglycosides.

  4. Subtle differences in molecular recognition between modified glycopeptide antibiotics and bacterial receptor peptides identified by electrospray ionization mass spectrometry

    DEFF Research Database (Denmark)

    Jørgensen, Thomas J. D.; Staroske, T; Roepstorff, P;

    1999-01-01

    showing that electrospray ionization mass spectrometry (ESI-MS) can be used in the rapid quantitative analysis of mixtures of vancomycin-group antibiotics and their bacterial cell-wall receptors allowing the identification of even subtle differences in binding constants. Differences in affinities...... are quantified for a mixture of vancomycin antibiotics (vancomycin, dechlorovancomycin and N-demethylvancomycin) and for a mixture of ristocetin A and its pseudoaglycone. Binding constants determined by ESI-MS were found to be in close agreement with those determined by more direct methods in aqueous solution....

  5. Multimodal fusion framework: a multiresolution approach for emotion classification and recognition from physiological signals.

    Science.gov (United States)

    Verma, Gyanendra K; Tiwary, Uma Shanker

    2014-11-15

    The purpose of this paper is twofold: (i) to investigate the emotion representation models and find out the possibility of a model with minimum number of continuous dimensions and (ii) to recognize and predict emotion from the measured physiological signals using multiresolution approach. The multimodal physiological signals are: Electroencephalogram (EEG) (32 channels) and peripheral (8 channels: Galvanic skin response (GSR), blood volume pressure, respiration pattern, skin temperature, electromyogram (EMG) and electrooculogram (EOG)) as given in the DEAP database. We have discussed the theories of emotion modeling based on i) basic emotions, ii) cognitive appraisal and physiological response approach and iii) the dimensional approach and proposed a three continuous dimensional representation model for emotions. The clustering experiment on the given valence, arousal and dominance values of various emotions has been done to validate the proposed model. A novel approach for multimodal fusion of information from a large number of channels to classify and predict emotions has also been proposed. Discrete Wavelet Transform, a classical transform for multiresolution analysis of signal has been used in this study. The experiments are performed to classify different emotions from four classifiers. The average accuracies are 81.45%, 74.37%, 57.74% and 75.94% for SVM, MLP, KNN and MMC classifiers respectively. The best accuracy is for 'Depressing' with 85.46% using SVM. The 32 EEG channels are considered as independent modes and features from each channel are considered with equal importance. May be some of the channel data are correlated but they may contain supplementary information. In comparison with the results given by others, the high accuracy of 85% with 13 emotions and 32 subjects from our proposed method clearly proves the potential of our multimodal fusion approach.

  6. Fatigue crack growth behavior and AE signal recognition from a composite patch repaired Ai thein plate

    International Nuclear Information System (INIS)

    The fatigue crack growth behavior of a fatigue-cracked and patch-repaired AA2024-T3 plate has been monitored. It was found that the overall crack growth rate was reduced and the crack propagation into the adjacent hole was also retarded. Signals due to crack growth after patch-repair and those due to debonding of the plate-patch interface were discriminated each other by using principal component analysis. The former showed higher center frequency and lower amplitude, whereas the latter showed longer rise time, lower frequency and higher amplitude.

  7. The two-component signal transduction system YvcPQ regulates the bacterial resistance to bacitracin in Bacillus thuringiensis.

    Science.gov (United States)

    Zhang, Shumeng; Li, Xinfeng; Wang, Xun; Li, Zhou; He, Jin

    2016-10-01

    YvcPQ is one of the two-component signal transduction systems that respond to specific stimuli and enable cells to adjust multiple cellular functions. It consists of a histidine kinase YvcQ and a response regulator YvcP. In this study, through searching the consensus sequence recognized by YvcP, we found four YvcP-binding motifs in the promoter regions of genes yvcR (BMB171_C4100), BMB171_C4385, kapD (BMB171_C4525) and BMB171_C4835 in Bacillus thuringiensis BMB171 which is a representative of Bacillus cereus group, and confirmed that these genes are regulated by YvcP. We compared the sequence of yvcPQ and its downstream genes in genus Bacillus, and found two different kinds of yvc locus, one was the yvcPQ-RS in B. subtilis species and the other was the yvcPQ-R-S1S2 in B. cereus group. Furthermore, we found that YvcP activates the transcription of yvcS1S2 (downstream of yvcR) to promote bacterial resistance to bacitracin and deletion of either yvcPQ operon or yvcS1S2 operon renders the bacterial cells more sensitive to bacitracin. This study enriched our understanding of both the YvcPQ's function and the mechanism of bacterial resistance to bacitracin.

  8. Bacterial Intoxication Evokes Cellular Senescence with Persistent DNA Damage and Cytokine Signaling

    DEFF Research Database (Denmark)

    Blazkova, Hana; Krejcikova, Katerina; Moudry, Pavel;

    2009-01-01

    Cytolethal distending toxins (CDTs) are proteins produced and secreted by facultative pathogenic strains of Gram-negative bacteria with potentially genotoxic effects. Mammalian cells exposed to CDTs undergo cell type-dependent cell-cycle arrest or apoptosis; however the cell fate responses to suc...... of this group of bacterial toxins, and warrant further investigation of their role(s) in human disease.......Cytolethal distending toxins (CDTs) are proteins produced and secreted by facultative pathogenic strains of Gram-negative bacteria with potentially genotoxic effects. Mammalian cells exposed to CDTs undergo cell type-dependent cell-cycle arrest or apoptosis; however the cell fate responses...... features shared by cells undergoing replicative or premature cellular senescence. We conclude that analogous to oncogenic, oxidative and replicative stresses, bacterial intoxication represents another pathophysiological stimulus that induces premature senescence, an intrinsic cellular response that may...

  9. [An Extraction and Recognition Method of the Distributed Optical Fiber Vibration Signal Based on EMD-AWPP and HOSA-SVM Algorithm].

    Science.gov (United States)

    Zhang, Yanjun; Liu, Wen-zhe; Fu, Xing-hu; Bi, Wei-hong

    2016-02-01

    Given that the traditional signal processing methods can not effectively distinguish the different vibration intrusion signal, a feature extraction and recognition method of the vibration information is proposed based on EMD-AWPP and HOSA-SVM, using for high precision signal recognition of distributed fiber optic intrusion detection system. When dealing with different types of vibration, the method firstly utilizes the adaptive wavelet processing algorithm based on empirical mode decomposition effect to reduce the abnormal value influence of sensing signal and improve the accuracy of signal feature extraction. Not only the low frequency part of the signal is decomposed, but also the high frequency part the details of the signal disposed better by time-frequency localization process. Secondly, it uses the bispectrum and bicoherence spectrum to accurately extract the feature vector which contains different types of intrusion vibration. Finally, based on the BPNN reference model, the recognition parameters of SVM after the implementation of the particle swarm optimization can distinguish signals of different intrusion vibration, which endows the identification model stronger adaptive and self-learning ability. It overcomes the shortcomings, such as easy to fall into local optimum. The simulation experiment results showed that this new method can effectively extract the feature vector of sensing information, eliminate the influence of random noise and reduce the effects of outliers for different types of invasion source. The predicted category identifies with the output category and the accurate rate of vibration identification can reach above 95%. So it is better than BPNN recognition algorithm and improves the accuracy of the information analysis effectively. PMID:27209772

  10. SigmoID: a user-friendly tool for improving bacterial genome annotation through analysis of transcription control signals.

    Science.gov (United States)

    Nikolaichik, Yevgeny; Damienikan, Aliaksandr U

    2016-01-01

    The majority of bacterial genome annotations are currently automated and based on a 'gene by gene' approach. Regulatory signals and operon structures are rarely taken into account which often results in incomplete and even incorrect gene function assignments. Here we present SigmoID, a cross-platform (OS X, Linux and Windows) open-source application aiming at simplifying the identification of transcription regulatory sites (promoters, transcription factor binding sites and terminators) in bacterial genomes and providing assistance in correcting annotations in accordance with regulatory information. SigmoID combines a user-friendly graphical interface to well known command line tools with a genome browser for visualising regulatory elements in genomic context. Integrated access to online databases with regulatory information (RegPrecise and RegulonDB) and web-based search engines speeds up genome analysis and simplifies correction of genome annotation. We demonstrate some features of SigmoID by constructing a series of regulatory protein binding site profiles for two groups of bacteria: Soft Rot Enterobacteriaceae (Pectobacterium and Dickeya spp.) and Pseudomonas spp. Furthermore, we inferred over 900 transcription factor binding sites and alternative sigma factor promoters in the annotated genome of Pectobacterium atrosepticum. These regulatory signals control putative transcription units covering about 40% of the P. atrosepticum chromosome. Reviewing the annotation in cases where it didn't fit with regulatory information allowed us to correct product and gene names for over 300 loci.

  11. SigmoID: a user-friendly tool for improving bacterial genome annotation through analysis of transcription control signals.

    Science.gov (United States)

    Nikolaichik, Yevgeny; Damienikan, Aliaksandr U

    2016-01-01

    The majority of bacterial genome annotations are currently automated and based on a 'gene by gene' approach. Regulatory signals and operon structures are rarely taken into account which often results in incomplete and even incorrect gene function assignments. Here we present SigmoID, a cross-platform (OS X, Linux and Windows) open-source application aiming at simplifying the identification of transcription regulatory sites (promoters, transcription factor binding sites and terminators) in bacterial genomes and providing assistance in correcting annotations in accordance with regulatory information. SigmoID combines a user-friendly graphical interface to well known command line tools with a genome browser for visualising regulatory elements in genomic context. Integrated access to online databases with regulatory information (RegPrecise and RegulonDB) and web-based search engines speeds up genome analysis and simplifies correction of genome annotation. We demonstrate some features of SigmoID by constructing a series of regulatory protein binding site profiles for two groups of bacteria: Soft Rot Enterobacteriaceae (Pectobacterium and Dickeya spp.) and Pseudomonas spp. Furthermore, we inferred over 900 transcription factor binding sites and alternative sigma factor promoters in the annotated genome of Pectobacterium atrosepticum. These regulatory signals control putative transcription units covering about 40% of the P. atrosepticum chromosome. Reviewing the annotation in cases where it didn't fit with regulatory information allowed us to correct product and gene names for over 300 loci. PMID:27257541

  12. SigmoID: a user-friendly tool for improving bacterial genome annotation through analysis of transcription control signals

    Science.gov (United States)

    Damienikan, Aliaksandr U.

    2016-01-01

    The majority of bacterial genome annotations are currently automated and based on a ‘gene by gene’ approach. Regulatory signals and operon structures are rarely taken into account which often results in incomplete and even incorrect gene function assignments. Here we present SigmoID, a cross-platform (OS X, Linux and Windows) open-source application aiming at simplifying the identification of transcription regulatory sites (promoters, transcription factor binding sites and terminators) in bacterial genomes and providing assistance in correcting annotations in accordance with regulatory information. SigmoID combines a user-friendly graphical interface to well known command line tools with a genome browser for visualising regulatory elements in genomic context. Integrated access to online databases with regulatory information (RegPrecise and RegulonDB) and web-based search engines speeds up genome analysis and simplifies correction of genome annotation. We demonstrate some features of SigmoID by constructing a series of regulatory protein binding site profiles for two groups of bacteria: Soft Rot Enterobacteriaceae (Pectobacterium and Dickeya spp.) and Pseudomonas spp. Furthermore, we inferred over 900 transcription factor binding sites and alternative sigma factor promoters in the annotated genome of Pectobacterium atrosepticum. These regulatory signals control putative transcription units covering about 40% of the P. atrosepticum chromosome. Reviewing the annotation in cases where it didn’t fit with regulatory information allowed us to correct product and gene names for over 300 loci. PMID:27257541

  13. Feature Selection Method Based on Neighborhood Relationships: Applications in EEG Signal Identification and Chinese Character Recognition

    Science.gov (United States)

    Zhao, Yu-Xiang; Chou, Chien-Hsing

    2016-01-01

    In this study, a new feature selection algorithm, the neighborhood-relationship feature selection (NRFS) algorithm, is proposed for identifying rat electroencephalogram signals and recognizing Chinese characters. In these two applications, dependent relationships exist among the feature vectors and their neighboring feature vectors. Therefore, the proposed NRFS algorithm was designed for solving this problem. By applying the NRFS algorithm, unselected feature vectors have a high priority of being added into the feature subset if the neighboring feature vectors have been selected. In addition, selected feature vectors have a high priority of being eliminated if the neighboring feature vectors are not selected. In the experiments conducted in this study, the NRFS algorithm was compared with two feature algorithms. The experimental results indicated that the NRFS algorithm can extract the crucial frequency bands for identifying rat vigilance states and identifying crucial character regions for recognizing Chinese characters. PMID:27314346

  14. Regulation of DMBT1 via NOD2 and TLR4 in intestinal epithelial cells modulates bacterial recognition and invasion

    DEFF Research Database (Denmark)

    Rosenstiel, Philip; Sina, Christian; End, Caroline;

    2007-01-01

    -kappaB activation and cytokine secretion in vitro. Thus, DMBT1 may play an important role in the first line of mucosal defense conferring immune exclusion of bacterial cell wall components. Dysregulated intestinal DMBT1 expression due to mutations in the NOD2/CARD15 gene may be part of the complex pathophysiology......Mucosal epithelial cell layers are constantly exposed to a complex resident microflora. Deleted in malignant brain tumors 1 (DMBT1) belongs to the group of secreted scavenger receptor cysteine-rich proteins and is considered to be involved in host defense by pathogen binding. This report describes...... intracellular pathogen receptor NOD2 via NF-kappaB activation. DMBT1 is strongly up-regulated in the inflamed intestinal mucosa of Crohn's disease patients with wild-type, but not with mutant NOD2. We show that DMBT1 inhibits cytoinvasion of Salmonella enterica and LPS- and muramyl dipeptide-induced NF...

  15. Longitudinal analysis of vaginal microbiome dynamics in women with recurrent bacterial vaginosis: recognition of the conversion process.

    Directory of Open Access Journals (Sweden)

    Janet A Lambert

    Full Text Available Bacterial vaginosis (BV affects ∼ 30% of women of reproductive age, has a high rate of recurrence, and is associated with miscarriage, preterm birth, and increased risk of acquiring other sexually transmitted infections, including HIV-1. Little is known of the daily changes in the vaginal bacterial composition as it progresses from treatment to recurrence, or whether any of these might be useful in its prediction or an understanding of its causes. We used phylogenetic branch-inclusive quantitative PCR (PB-qPCR and Lactobacillus blocked/unblocked qPCR (Lb-qPCR to characterize longitudinal changes in the vaginal microbiota in sequential vaginal self-swabs from five women with recurrent BV, from diagnosis through remission to recurrence. Both patients with acute BV samples dominated by G. vaginalis recurred during the study with similar profiles, whereas the three patients with acute BV samples dominated by other anaerobes did not recur or recurred to an intermediate Nugent score. L. iners dominated remission phases, with intermittent days of abnormal microbial profiles typically associated with menses. The exception was a newly discovered phenomenon, a sustained period of abnormal profiles, termed conversion, which preceded symptomatic acute BV. Species known to have antagonistic activity towards Lactobacillus were detected in pre-conversion samples, possibly contributing to the decline in Lactobacillus. Lb-qPCR scores define two categories of response in the initial post-treatment visit samples; scores 8 may predict delayed or no recurrence. Amsel criteria or Nugent scores did not have this potential predictive capability. Larger studies are warranted to evaluate the prognostic potential of detecting conversion and poor Lb-qPCR scores at the post-treatment visit of recurrent BV patients.

  16. Porphyromonas gingivalis manipulates complement and TLR signaling to uncouple bacterial clearance from inflammation and promote dysbiosis

    Science.gov (United States)

    Maekawa, Tomoki; Krauss, Jennifer L.; Abe, Toshiharu; Jotwani, Ravi; Triantafilou, Martha; Triantafilou, Kathy; Hashim, Ahmed; Hoch, Shifra; Curtis, Michael A.; Nussbaum, Gabriel; Lambris, John D.; Hajishengallis, George

    2014-01-01

    SUMMARY Certain low-abundance bacterial species, such as the periodontitis-associated oral bacterium Porphyromonas gingivalis can subvert host immunity to remodel a normally symbiotic microbiota into a dysbiotic, disease-provoking state. However, such pathogens also exploit inflammation to thrive in dysbiotic conditions. How these bacteria evade immunity while maintaining inflammation is unclear. As previously reported, P. gingivalis remodels the oral microbiota into a dysbiotic state by exploiting complement. Now we show that in neutrophils P. gingivalis disarms a host-protective TLR2-MyD88 pathway via proteasomal degradation of MyD88, whereas it activates an alternate TLR2-Mal-PI3K pathway. This alternate TLR2-Mal-PI3K pathway blocks phagocytosis, provides ‘bystander’ protection to otherwise susceptible bacteria, and promotes dysbiotic inflammation in vivo. This mechanism to disengage bacterial clearance from inflammation required an intimate crosstalk between TLR2 and the complement receptor C5aR, and can contribute to the persistence of microbial communities that drive dysbiotic diseases. PMID:24922578

  17. 基于KPCA和LDA的信号调制识别%Signal modulation recognition based on KPCA and LDA

    Institute of Scientific and Technical Information of China (English)

    周欣; 吴瑛

    2011-01-01

    Aiming at the problem of signal feature selection and classification, an algorithm of kernel principle component analysis (KPCA) and linear discriminant analysis (LDA) classifier is brought forward According to the characteristic of communication signals, first the eliminating correlation and dimensionality reduction for these feature parameters are realized using a KPCA approach Then the automatic recognition of modulation signals is designed by the LDA classifier. Simulation result shows that over a wide range of signal-to-noise ratio scenarios, KPCA has a high performance in nonlinear classified feature The classification accuracy based on KPCA+LDA is higher than prinaple component analysis (PCA)+ template matching. Through analysis it can also be seen that the KPCA+LDA algorithm is equal to the method of kemel Fisher discriminant analysis (KFDA).%对信号的特征选择与分类问题进行研究,提出了一种基于核主分量分析(kernel principle component analysis,KPCA)和线性判别(1inear discriminant analysis,LDA)分类器的信号调制识别算法.针对通信信号的特点,首先利用KPCA的方法对特征参数进行主分量组合,以消除信号特征间的相关性和压缩特征向量的维教,然后利用LDA分类器进行信号调制方式的自动识别.仿真表明,在一个较大的信噪比范围内当特征非线性可分时,KPCA在特征选择方面性能更优,且基于KPCA+LDA的识别方法精度高于主分量分析(principle component analysis,PCA)+模板匹配算法.通过分析还可得出,KPCA+LDA等价于基于核的Fisher判别分析(kernel Fisher diseriminant analysis,KFDA)方法.

  18. [A case of chronic myopathy associated with an antibody to signal recognition particle (SRP) following long-term asymptomatic hypercreatinekinasemia].

    Science.gov (United States)

    Itaya, Kazuhiro; Inoue, Manabu; Iwanami, Hiroaki; Oonaka, Youhei; Jimi, Takahiro; Ichikawa, Hiroo

    2015-01-01

    A 65-year-old man first visited our hospital due to hypercreatinekinasemia (hyperCKemia) (669 IU/l) 12 years ago at age 53. At that time, he had normal muscle strength without other neurological deficits, electromyography (EMG) was normal, and a muscle biopsy obtained from the biceps brachii was intact in routine histochemical studies. These findings led to a diagnosis of idiopathic hyperCKemia that lasted for over a decade. At age 65, the patient became aware of muscle weakness and serum CK was elevated to 4,846 IU/l. Neurological examination revealed very mild atrophy in both thighs, proximal muscle weakness in the left upper and right lower limbs without myalgia, grasping pain, joint pain, and skin lesions. A typical myogenic pattern was detected on EMG exclusively in proximal limb muscles, and fat-suppressed MRI showed high intensity signal areas in adductor magnus muscles. The clinical diagnosis was limb-girdle muscular dystrophy, but MRI findings suggestive of an inflammatory process prompted us to perform muscle biopsy at the rectus femoris. The pathology had characteristic features of necrotizing myopathy containing necrotic and regenerating fibers without prominent inflammatory cell infiltration. Serum anti-signal recognition particle (SRP) antibodies were found to be positive and the final diagnosis was anti-SRP antibody myopathy. Muscle weakness progressed slowly despite therapy with oral corticosteroids. Addition of intravenous high-dose immunoglobulin therapy led to an apparent improvement of muscle weakness in parallel with lowering of the serum CK level. In those who were thought to be idiopathic hyperCKemia or hereditary muscle disorders, potential immunotherapy-effective group does exist. We suggest considering such cases including anti-SRP antibody myopathy during diagnosis, and non-invasive MRI study may be useful to differentiate immunotherapy-effective group from hereditary muscle disorders. PMID:25904255

  19. Oryza sativa Chloroplast Signal Recognition Particle 43 (OscpSRP43 Is Required for Chloroplast Development and Photosynthesis.

    Directory of Open Access Journals (Sweden)

    Xiang-guang Lv

    Full Text Available A rice chlorophyll-deficient mutant w67 was isolated from an ethyl methane sulfonate (EMS-induced IR64 (Oryza sativa L. ssp. indica mutant bank. The mutant exhibited a distinct yellow-green leaf phenotype in the whole plant growth duration with significantly reduced levels of chlorophyll and carotenoid, impaired chloroplast development and lowered capacity of photosynthesis compared with the wild-type IR64. Expression of a number of genes associated with chlorophyll metabolism, chloroplast biogenesis and photosynthesis was significantly altered in the mutant. Genetic analysis indicated that the yellow-green phenotype was controlled by a single recessive nuclear gene located on the short arm of chromosome 3. Using map-based strategy, the mutation was isolated and predicted to encode a chloroplast signal recognition particle 43 KD protein (cpSRP43 with 388 amino acid residuals. A single base substitution from A to T at position 160 resulted in a premature stop codon. OscpSRP43 was constitutively expressed in various organs with the highest level in the leaf. Functional complementation could rescue the mutant phenotype and subcellular localization showed that the cpSRP43:GFP fusion protein was targeted to the chloroplast. The data suggested that Oryza sativa cpSRP43 (OscpSRP43 was required for the normal development of chloroplasts and photosynthesis in rice.

  20. Normal-hearing English-as-a-second-language listeners' recognition of English words in competing signals.

    Science.gov (United States)

    Shi, Lu-Feng

    2009-05-01

    English-as-a-second-language (ESL) listeners have difficulty perceiving English speech presented in background noise. The current study furthered this line of investigations by including participants who varied widely in their age of English acquisition and length of English learning: 24 native English monolingual (EML), 12 simultaneous bilingual (SBL), 10 early ESL (E-ESL), and 14 late ESL (L-ESL) listeners. Word recognition scores were obtained in quiet and in the presence of speech-weighted noise, multi-talker babble, forward-playing music, and time-reversed music. All words and competing signals were presented at 45 dB HL. EML and SBL listeners' performances were found to be similar across test conditions. ESL, especially L-ESL listeners, performed significantly more poorly in all conditions than EML and SBL listeners. Overall, speech-weighted noise and multi-talker babble showed greater masking effect than music; however, the difference in performance between L-ESL and EML listeners was the largest for the music maskers, indicating that L-ESL listeners are susceptible to weaker maskers. Age of acquisition and length of learning were both shown to be good indicators of SBL and ESL listeners' performance. PMID:19842801

  1. Oryza sativa Chloroplast Signal Recognition Particle 43 (OscpSRP43) Is Required for Chloroplast Development and Photosynthesis.

    Science.gov (United States)

    Lv, Xiang-guang; Shi, Yong-feng; Xu, Xia; Wei, Yan-lin; Wang, Hui-mei; Zhang, Xiao-bo; Wu, Jian-li

    2015-01-01

    A rice chlorophyll-deficient mutant w67 was isolated from an ethyl methane sulfonate (EMS)-induced IR64 (Oryza sativa L. ssp. indica) mutant bank. The mutant exhibited a distinct yellow-green leaf phenotype in the whole plant growth duration with significantly reduced levels of chlorophyll and carotenoid, impaired chloroplast development and lowered capacity of photosynthesis compared with the wild-type IR64. Expression of a number of genes associated with chlorophyll metabolism, chloroplast biogenesis and photosynthesis was significantly altered in the mutant. Genetic analysis indicated that the yellow-green phenotype was controlled by a single recessive nuclear gene located on the short arm of chromosome 3. Using map-based strategy, the mutation was isolated and predicted to encode a chloroplast signal recognition particle 43 KD protein (cpSRP43) with 388 amino acid residuals. A single base substitution from A to T at position 160 resulted in a premature stop codon. OscpSRP43 was constitutively expressed in various organs with the highest level in the leaf. Functional complementation could rescue the mutant phenotype and subcellular localization showed that the cpSRP43:GFP fusion protein was targeted to the chloroplast. The data suggested that Oryza sativa cpSRP43 (OscpSRP43) was required for the normal development of chloroplasts and photosynthesis in rice.

  2. A bacterial signal peptidase enhances processing of a recombinant single chain antibody fragment in insect cells

    NARCIS (Netherlands)

    Ailor, E; Pathmanathan, J; Jongbloed, JDH; Betenbaugh, MJ

    1999-01-01

    The production of an antibody single chain fragment (scFv) in insect cells was accompanied by the formation of an insoluble intracellular precursor even with the inclusion of the bee melittin signal peptide. The presence of the precursor polypeptide suggests a limitation in the processing of the sig

  3. Impedimetric biosensor based on self-assembled hybrid cystein-gold nanoparticles and CramoLL lectin for bacterial lipopolysaccharide recognition.

    Science.gov (United States)

    Oliveira, Maria D L; Andrade, Cesar A S; Correia, Maria T S; Coelho, Luana C B B; Singh, Pankaj R; Zeng, Xiangqun

    2011-10-01

    We report the development of a new selective and specific electrochemical biosensor for bacterial lipolysaccharide (LPS). An electrode interface was constructed using a l-cysteine-gold nanoparticle (AuNpCys) composite to be immobilized by electrostatic interaction in the network of a poly(vinyl chloride-vinyl acetate maleic acid) (PVM) layer on a gold bare electrode. The impedimetric biosensor is fabricated by self-assembled CramoLL lectin on the PVM-AuNpCys-modified gold electrode through electrostatic interaction. CramoLL is used as the recognition interface. AFM images showed that LPS was specifically recognized on the PVM-AuNpCys-CramoLL system surface. The measurements of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) showed that the electrochemical response of a redox probe system (K(4)[Fe(CN)(6)](4-)/K(3)[Fe(CN)(6)](3-)) were blocked, due to the procedures of modified electrode with PVM-AuNpCys-CramoLL. In the majority of the experiments the lectin retained its activity as observed through its interaction with LPS from Escherichia coli, Serratia marcescens, Salmonella enterica and Klebsiella pneumoniae. The results are expressed in terms of the charge transfer resistance and current peak anodic using the EIS and CV techniques for the development of a biosensor for contamination by endotoxins. A new type of sensor for selective discrimination of LPS types with a high sensitivity has been obtained. PMID:21752390

  4. Investigating a possible role for the bacterial signal molecules N-acylhomoserine lactones in Balanus improvisus cyprid settlement.

    Science.gov (United States)

    Tait, Karen; Havenhand, Jon

    2013-05-01

    Increased settlement on bacterial biofilms has been demonstrated for a number of marine invertebrate larvae, but the nature of the cue(s) responsible is not well understood. We tested the hypothesis that the bay barnacle Balanus improvisus utilizes the bacterial signal molecules N-acylhomoserine lactones (AHLs) as a cue for the selection of sites for permanent attachment. Single species biofilms of the AHL-producing bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp. BR1 were attractive to settling cypris larvae of B. improvisus. However, when AHL production was inactivated, either by mutation of the AHL synthetic genes or by expression of an AHL-degrading gene (aiiA), the ability of the bacteria to attract cyprids was abolished. In addition, cyprids actively explored biofilms of E. coli expressing the recombinant AHL synthase genes luxI from Vibrio fischeri (3-oxo-C6-HSL), rhlI from Pseudomonas aeruginosa (C4-HSL/C6-HSL), vanI from V. anguillarum (3-oxo-C10-HSL) and sulI from Sulfitobacter sp. BR1 (C4-HSL, 3-hydroxy-C6-HSL, C8-HSL and 3-hydroxy-C10-HSL), but not E. coli that did not produce AHLs. Finally, synthetic AHLs (C8-HSL, 3-oxo-C10-HSL and C12-HSL) at concentrations similar to those found within natural biofilms (5 μm) resulted in increased cyprid settlement. Thus, B. improvisus cypris exploration of and settlement on biofilms appears to be mediated by AHL-signalling bacteria in the laboratory. This adds to our understanding of how quorum sensing inhibition may be used as for biofouling control. Nonetheless, the significance of our results for larvae settling naturally in the field, and the mechanisms that underlay the observed responses to AHLs, is as yet unknown.

  5. THE TRANSMEMBRANE SIGNAL TRANSDUCTION IN HEp-2 CELLS INDUCED BY BACTERIAL ADHERENCE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ In order to understand the role of transmembrane signal transduction of host cells in the early steps of infection,the adherence of E. coli to HEp-2 cells and the change of activity of phospholipase C-γ (PLC-γ) induced by the adherence were investigated.The adherence of enteropathogenic E.coli (EPEC), strain E.7, induced a significant increase of inositol-triphosphat (IP-3) level in HEp-2 cells. The adherence of the bacteria and the increase of IP-3 was kinetically correlated. Whereas the increase of IP3 level induced by the adherence of the control strain EPEC (H511), a non-piliated strain, was much meager than that by E7, a piliated strain. The results highlighted an important role of transmembrane signals like IP-3 in the pathogenesis of EPEC.

  6. The contribution of cell-cell signaling and motility to bacterial biofilm formation

    DEFF Research Database (Denmark)

    Shrout, Joshua D; Tolker-Nielsen, Tim; Givskov, Michael;

    2011-01-01

    Many bacteria grow attached to a surface as biofilms. Several factors dictate biofilm formation, including responses by the colonizing bacteria to their environment. Here we review how bacteria use cell-cell signaling (also called quorum sensing) and motility during biofilm formation. Specifically...... gene expression important to the production of polysaccharides, rhamnolipid, and other virulence factors. Surface motility affects the assembly and architecture of biofilms, and some aspects of motility are also influenced by quorum sensing. While some genes and their function are specific to P....... aeruginosa, many aspects of biofilm development can be used as a model system to understand how bacteria differentially colonize surfaces....

  7. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling

    Directory of Open Access Journals (Sweden)

    Mina eAziz

    2016-04-01

    Full Text Available Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant’s growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03 transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm. In contrast, a previously-characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against beet armyworm feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense.

  8. Autoinducer 2: A concentration-dependent signal for mutualistic bacterial biofilm growth

    Science.gov (United States)

    Rickard, A.H.; Palmer, R.J.; Blehert, D.S.; Campagna, S.R.; Semmelhack, M.F.; Egland, P.G.; Bassler, B.L.; Kolenbrander, P.E.

    2006-01-01

    4,5-dihydroxy-2,3-pentanedione (DPD), a product of the LuxS enzyme in the catabolism of S-ribosylhomocysteine, spontaneously cyclizes to form autoinducer 2 (AI-2). AI-2 is proposed to be a universal signal molecule mediating interspecies communication among bacteria. We show that mutualistic and abundant biofilm growth in flowing saliva of two human oral commensal bacteria, Actinomyces naeslundii T14V and Streptococcus oralis 34, is dependent upon production of AI-2 by S. oralis 34. A luxS mutant of S. oralis 34 was constructed which did not produce AI-2. Unlike wild-type dual-species biofilms, A. naeslundii T14V and an S. oralis 34 luxS mutant did not exhibit mutualism and generated only sparse biofilms which contained a 10-fold lower biomass of each species. Restoration of AI-2 levels by genetic or chemical (synthetic AI-2 in the form of DPD) complementation re-established the mutualistic growth and high biomass characteristic for the wild-type dual-species biofilm. Furthermore, an optimal concentration of DPD was determined, above and below which biofilm formation was suppressed. The optimal concentration was 100-fold lower than the detection limit of the currently accepted AI-2 assay. Thus, AI-2 acts as an interspecies signal and its concentration is critical for mutualism between two species of oral bacteria grown under conditions that are representative of the human oral cavity. ?? 2006 Blackwell Publishing Ltd.

  9. Augmenting Sulfur Metabolism and Herbivore Defense in Arabidopsis by Bacterial Volatile Signaling.

    Science.gov (United States)

    Aziz, Mina; Nadipalli, Ranjith K; Xie, Xitao; Sun, Yan; Surowiec, Kazimierz; Zhang, Jin-Lin; Paré, Paul W

    2016-01-01

    Sulfur is an element necessary for the life cycle of higher plants. Its assimilation and reduction into essential biomolecules are pivotal factors determining a plant's growth and vigor as well as resistance to environmental stress. While certain soil microbes can enhance ion solubility via chelating agents or oxidation, microbial regulation of plant-sulfur assimilation has not been reported. With an increasing understanding that soil microbes can activate growth and stress tolerance in plants via chemical signaling, the question arises as to whether such beneficial bacteria also regulate sulfur assimilation. Here we report a previously unidentified mechanism by which the growth-promoting rhizobacterium Bacillus amyloliquefaciens (GB03) transcriptionally activates genes responsible for sulfur assimilation, increasing sulfur uptake and accumulation in Arabidopsis. Transcripts encoding for sulfur-rich aliphatic and indolic glucosinolates are also GB03 induced. As a result, GB03-exposed plants with elevated glucosinolates exhibit greater protection against the generalist herbivore, Spodoptera exigua (beet armyworm, BAW). In contrast, a previously characterized glucosinolate mutant compromised in the production of both aliphatic and indolic glucosinolates is also compromised in terms of GB03-induced protection against insect herbivory. As with in vitro studies, soil-grown plants show enhanced glucosinolate accumulation and protection against BAW feeding with GB03 exposure. These results demonstrate the potential of microbes to enhance plant sulfur assimilation and emphasize the sophisticated integration of microbial signaling in plant defense. PMID:27092166

  10. Degradation of Bacterial Quorum Sensing Signaling Molecules by the Microscopic Yeast Trichosporon loubieri Isolated from Tropical Wetland Waters

    Directory of Open Access Journals (Sweden)

    Cheng-Siang Wong

    2013-09-01

    Full Text Available Proteobacteria produce N-acylhomoserine lactones as signaling molecules, which will bind to their cognate receptor and activate quorum sensing-mediated phenotypes in a population-dependent manner. Although quorum sensing signaling molecules can be degraded by bacteria or fungi, there is no reported work on the degradation of such molecules by basidiomycetous yeast. By using a minimal growth medium containing N-3-oxohexanoylhomoserine lactone as the sole source of carbon, a wetland water sample from Malaysia was enriched for microbial strains that can degrade N-acylhomoserine lactones, and consequently, a basidiomycetous yeast strain WW1C was isolated. Morphological phenotype and molecular analyses confirmed that WW1C was a strain of Trichosporon loubieri. We showed that WW1C degraded AHLs with N-acyl side chains ranging from 4 to 10 carbons in length, with or without oxo group substitutions at the C3 position. Re-lactonisation bioassays revealed that WW1C degraded AHLs via a lactonase activity. To the best of our knowledge, this is the first report of degradation of N-acyl-homoserine lactones and utilization of N-3-oxohexanoylhomoserine as carbon and nitrogen source for growth by basidiomycetous yeast from tropical wetland water; and the degradation of bacterial quorum sensing molecules by an eukaryotic yeast.

  11. Solid-State NMR on bacterial cells: selective cell wall signal enhancement and resolution improvement using dynamic nuclear polarization

    International Nuclear Information System (INIS)

    Dynamic nuclear polarization (DNP) enhanced solid-state nuclear magnetic resonance (NMR) has recently emerged as a powerful technique for the study of material surfaces. In this study, we demonstrate its potential to investigate cell surface in intact cells. Using Bacillus subtilis bacterial cells as an example, it is shown that the polarizing agent 1-(TEMPO-4-oxy)-3-(TEMPO-4-amino)propan-2-ol (TOTAPOL) has a strong binding affinity to cell wall polymers (peptidoglycan). This particular interaction is thoroughly investigated with a systematic study on extracted cell wall materials, disrupted cells, and entire cells, which proved that TOTAPOL is mainly accumulating in the cell wall. This property is used on one hand to selectively enhance or suppress cell wall signals by controlling radical concentrations and on the other hand to improve spectral resolution by means of a difference spectrum. Comparing DNP-enhanced and conventional solid-state NMR, an absolute sensitivity ratio of 24 was obtained on the entire cell sample. This important increase in sensitivity together with the possibility of enhancing specifically cell wall signals and improving resolution really opens new avenues for the use of DNP-enhanced solid-state NMR as an on-cell investigation tool. (authors)

  12. Mechanism of bacterial signal transduction revealed by molecular dynamics of Tsr dimers and trimers of dimers in lipid vesicles.

    Directory of Open Access Journals (Sweden)

    Benjamin A Hall

    Full Text Available Bacterial chemoreceptors provide an important model for understanding signalling processes. In the serine receptor Tsr from E. coli, a binding event in the periplasmic domain of the receptor dimer causes a shift in a single transmembrane helix of roughly 0.15 nm towards the cytoplasm. This small change is propagated through the ≈ 22 nm length of the receptor, causing downstream inhibition of the kinase CheA. This requires interactions within a trimer of receptor dimers. Additionally, the signal is amplified across a 53,000 nm(2 array of chemoreceptor proteins, including ≈ 5,200 receptor trimers-of-dimers, at the cell pole. Despite a wealth of experimental data on the system, including high resolution structures of individual domains and extensive mutagenesis data, it remains uncertain how information is communicated across the receptor from the binding event to the downstream effectors. We present a molecular model of the entire Tsr dimer, and examine its behaviour using coarse-grained molecular dynamics and elastic network modelling. We observe a large bending in dimer models between the linker domain HAMP and coiled-coil domains, which is supported by experimental data. Models of the trimer of dimers, built from the dimer models, are more constrained and likely represent the signalling state. Simulations of the models in a 70 nm diameter vesicle with a biologically realistic lipid mixture reveal specific lipid interactions and oligomerisation of the trimer of dimers. The results indicate a mechanism whereby small motions of a single helix can be amplified through HAMP domain packing, to initiate large changes in the whole receptor structure.

  13. Study of signal recognition of radar emitter based on QPSO%基于QPSO的雷达辐射源信号识别方法研究

    Institute of Scientific and Technical Information of China (English)

    郭戈; 徐佳婧; 徐璟; 魏洁

    2014-01-01

    鉴于支持向量机(SVM)方法对雷达辐射源信号具有较理想的识别结果,但对模型参数没有具体选择方法的问题,设计了一种以具有量子行为的粒子群优化(QPSO)算法为参数优化方法的SVM分类器,并提出了基于QPSO-SVM的雷达辐射源信号识别方法.QPSO-SVM分类器在采用QPSO算法对SVM进行优化改进的同时,继承了SVM分类器泛化能力强的特点,对雷达辐射源信号识别问题具有良好的适应性.实验结果表明,与其他方法相比,本文方法在保证识别准确率的同时,降低了参数选择时间.%Considering that the SVM algorithm has an ideal recognition result for radar emitter signals, but no specific selection method for the model parameters, this paper designs an SVM classifier that uses QPSO algorithm as the optimization algorithm of parameters, and proposes a scheme of signal recognition of radar emitter based on QPSO-SVM. While the QPSO-SVM classifier optimizes and improves SVM using the QPSO algorithm, the proposed classifier keeps the strong generalization capability of SVM classifier, thus having the better adaptability for the signal recognition of radar emitter. Experimental results show that this proposed method can shorten the time for parameter selection while guaranteeing the accuracy rate of recognition, compared with other algorithms.

  14. Selective Protection of an ARF1-GTP Signaling Axis by a Bacterial Scaffold Induces Bidirectional Trafficking Arrest

    Directory of Open Access Journals (Sweden)

    Andrey S. Selyunin

    2014-03-01

    Full Text Available Bidirectional vesicular transport between the endoplasmic reticulum (ER and Golgi is mediated largely by ARF and Rab GTPases, which orchestrate vesicle fission and fusion, respectively. How their activities are coordinated in order to define the successive steps of the secretory pathway and preserve traffic directionality is not well understood in part due to the scarcity of molecular tools that simultaneously target ARF and Rab signaling. Here, we take advantage of the unique scaffolding properties of E. coli secreted protein G (EspG to describe the critical role of ARF1/Rab1 spatiotemporal coordination in vesicular transport at the ER-Golgi intermediate compartment. Structural modeling and cellular studies show that EspG induces bidirectional traffic arrest by tethering vesicles through select ARF1-GTP/effector complexes and local inactivation of Rab1. The mechanistic insights presented here establish the effectiveness of a small bacterial catalytic scaffold for studying complex processes and reveal an alternative mechanism of immune regulation by an important human pathogen.

  15. 基于生理信号的观众情感状态识别模型%Physiological signals based emotional state recognition model of audience

    Institute of Scientific and Technical Information of China (English)

    叶晓菡; 陈岭; 姜贤塔; 陈根才

    2012-01-01

    To study the relationship between movie plot and the physiological signals of audience, a physiological signals based emotional state recognition model of movie audience was proposed. Features were extracted from physiological signals, and sequential forward selection (SFS) method was used for feature selection purpose. The emotional state recognition model was built based on support vector machine (SVM). Experiments were conducted to evaluate the performance of the model. In the experiments, three movies with different types were employed. During watching these movies, the facial expressions and physiological signals of 11 participants were recorded, and the human judgment of the emotional states of the participants was obtained based on their facial expressions. The experimental results indicate that the proposed model can distinguish among various emotional states, and the average recognition rate is higher than 90%.%为研究电影情节与观众生理信号变化的关系,提出基于生理信号的观众情感状态识别模型,从观众生理信号中提取特征,采用顺序前进法(SFS)进行特征选择,并基于支持向量机(SVM)建立观众情感状态识别模型.实验选择了不同类型的3部影片,共11名人员参加,在电影播放时拍摄观众表情并记录其生理信号,基于表情人工标注其情感状态.实验结果表明:该模型对各情感状态的区分较理想,平均识别率在90%以上.

  16. A proteomic analysis of Arabidopsis thaliana seedling responses to 3-oxo-octanoyl-homoserine lactone, a bacterial quorum-sensing signal

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Chunjuan, E-mail: chunjuanjay@163.com [Biology Institute, Hebei Academy of Sciences, Shijiazhuang 050051 (China); Hebei Engineering and Technology Center of Microbiological Control on Main Crop Disease, Shijiazhuang 050051 (China); Liu, Fang, E-mail: liufang830818@126.com [Biology Institute, Hebei Academy of Sciences, Shijiazhuang 050051 (China); Hebei Engineering and Technology Center of Microbiological Control on Main Crop Disease, Shijiazhuang 050051 (China); Zhao, Qian, E-mail: zhqbluesea@163.com [Biology Institute, Hebei Academy of Sciences, Shijiazhuang 050051 (China); Hebei Engineering and Technology Center of Microbiological Control on Main Crop Disease, Shijiazhuang 050051 (China); Jia, Zhenhua, E-mail: zhenhuaj@hotmail.com [Biology Institute, Hebei Academy of Sciences, Shijiazhuang 050051 (China); Hebei Engineering and Technology Center of Microbiological Control on Main Crop Disease, Shijiazhuang 050051 (China); Song, Shuishan, E-mail: shuishans@hotmail.com [Biology Institute, Hebei Academy of Sciences, Shijiazhuang 050051 (China); Hebei Engineering and Technology Center of Microbiological Control on Main Crop Disease, Shijiazhuang 050051 (China)

    2012-10-19

    Highlights: Black-Right-Pointing-Pointer 3OC8-HSL can change the expression of diverse proteins in Arabidopsis. Black-Right-Pointing-Pointer 3OC8-HSL responsive proteins were identified using MALDI-TOF-MS. Black-Right-Pointing-Pointer Plant could have an extensive range of functional responses to bacterial AHL. -- Abstract: N-acyl-homoserine lactones (AHLs) are a class of bacterial quorum-sensing (QS) signals that are commonly used by Gram-negative bacteria for cell-to-cell communication. Recently, it has become evident that AHLs can regulate plant root growth and trigger plant defense responses; however, little is known about the plant response mechanisms to bacterial QS signals. In this study, we used a proteomic approach to investigate the responses of Arabidopsis thaliana seedlings to N-3-oxo-octanoyl-homoserine lactone (3OC8-HSL), a bacterial QS signal. The results revealed that the abundance of 53 protein spots was significantly altered; two thirds of these proteins were found to be up-regulated after 3OC8-HSL treatment. Thirty-four proteins were identified using MALDI-TOF-MS. These 3OC8-HSL-responsive proteins, in addition to one protein of unknown function, are implicated in a variety of physiological processes, including metabolism of carbohydrate and energy, protein biosynthesis and quality control systems, defense response and signal transduction and cytoskeleton remodeling. Our bioinformatic analysis indicated that the chloroplasts are the intracellular organelles most influenced by the exposure to 3OC8-HSL. Our data indicate that plants have an extensive range of functional responses to bacterial AHLs that may play important roles in the interaction between plants and bacteria.

  17. Exposure to bacterial signals does not alter pea aphids' survival upon a second challenge or investment in production of winged offspring.

    Directory of Open Access Journals (Sweden)

    Bas ter Braak

    Full Text Available Pea aphids have an obligate nutritional symbiosis with the bacteria Buchneraaphidicola and frequently also harbor one or more facultative symbionts. Aphids are also susceptible to bacterial pathogen infections, and it has been suggested that aphids have a limited immune response towards such pathogen infections compared to other, more well-studied insects. However, aphids do possess at least some of the genes known to be involved in bacterial immune responses in other insects, and immune-competent hemocytes. One possibility is that immune priming with microbial elicitors could stimulate immune protection against subsequent bacterial infections, as has been observed in several other insect systems. To address this hypothesis we challenged aphids with bacterial immune elicitors twenty-four hours prior to live bacterial pathogen infections and then compared their survival rates to aphids that were not pre-exposed to bacterial signals. Using two aphid genotypes, we found no evidence for immune protection conferred by immune priming during infections with either Serratia marcescens or with Escherichia coli. Immune priming was not altered by the presence of facultative, beneficial symbionts in the aphids. In the absence of inducible immune protection, aphids may allocate energy towards other defense traits, including production of offspring with wings that could escape deteriorating conditions. To test this, we monitored the ratio of winged to unwinged offspring produced by adult mothers of a single clone that had been exposed to bacterial immune elicitors, to live E. coli infections or to no challenge. We found no correlation between immune challenge and winged offspring production, suggesting that this mechanism of defense, which functions upon exposure to fungal pathogens, is not central to aphid responses to bacterial infections.

  18. 磁探搜潜系统的目标信号识别%Magnetec Probe Anti-submarine System Target Signal Recognition

    Institute of Scientific and Technical Information of China (English)

    尹景涯

    2012-01-01

    This paper mainly introduces the system structure and working principle of magnetic anomaly detector.Focus on the magnetic detector of magnetic target signal recognition fuction,and the prospect of future development of magnetic anomaly detector.%文章主要介绍了磁探仪的系统结构和工作原理,重点介绍了磁探仪对磁目标信号的识别功能,以及对磁探仪未来发展的展望。

  19. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated...

  20. Are bacterial volatile compounds poisonous odors to a fungal pathogen Botrytis cinerea, alarm signals to Arabidopsis seedlings for eliciting induced resistance, or both?

    Directory of Open Access Journals (Sweden)

    Choong-Min eRyu

    2016-02-01

    Full Text Available Biological control (biocontrol agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR. Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 hours post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen

  1. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    Science.gov (United States)

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Emerging data suggest that bacterial VOCs also can directly inhibit fungal and plant growth. The aim of the current study was to differentiate direct and indirect mechanisms of bacterial VOC effects against Botrytis cinerea infection of Arabidopsis. Volatile emissions from Bacillus subtilis GB03 successfully protected Arabidopsis seedlings against B. cinerea. First, we investigated the direct effects of bacterial VOCs on symptom development and different phenological stages of B. cinerea including spore germination, mycelial attachment to the leaf surface, mycelial growth, and sporulation in vitro and in planta. Volatile emissions inhibited hyphal growth in a dose-dependent manner in vitro, and interfered with fungal attachment on the hydrophobic leaf surface. Second, the optimized bacterial concentration that did not directly inhibit fungal growth successfully protected Arabidopsis from fungal infection, which indicates that bacterial VOC-elicited plant ISR has a more important role in biocontrol than direct inhibition of fungal growth on Arabidopsis. We performed qRT-PCR to investigate the priming of the defense-related genes PR1, PDF1.2, and ChiB at 0, 12, 24, and 36 h post-infection and 14 days after the start of plant exposure to bacterial VOCs. The results indicate that bacterial VOCs potentiate expression of PR1 and PDF1.2 but not ChiB, which stimulates SA- and JA-dependent signaling pathways in plant ISR and protects plants against pathogen colonization. This study

  2. Genetic evidence for a tight cooperation of TatB and TatC during productive recognition of twin-arginine (Tat signal peptides in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Frank Lausberg

    Full Text Available The twin arginine translocation (Tat pathway transports folded proteins across the cytoplasmic membrane of bacteria. Tat signal peptides contain a consensus motif (S/T-R-R-X-F-L-K that is thought to play a crucial role in substrate recognition by the Tat translocase. Replacement of the phenylalanine at the +2 consensus position in the signal peptide of a Tat-specific reporter protein (TorA-MalE by aspartate blocked export of the corresponding TorA(D(+2-MalE precursor, indicating that this mutation prevents a productive binding of the TorA(D(+2 signal peptide to the Tat translocase. Mutations were identified in the extreme amino-terminal regions of TatB and TatC that synergistically suppressed the export defect of TorA(D(+2-MalE when present in pairwise or triple combinations. The observed synergistic suppression activities were even more pronounced in the restoration of membrane translocation of another export-defective precursor, TorA(KQ-MalE, in which the conserved twin arginine residues had been replaced by lysine-glutamine. Collectively, these findings indicate that the extreme amino-terminal regions of TatB and TatC cooperate tightly during recognition and productive binding of Tat-dependent precursor proteins and, furthermore, that TatB and TatC are both involved in the formation of a specific signal peptide binding site that reaches out as far as the end of the TatB transmembrane segment.

  3. Exploratory Data Analysis of Acceleration Signals to Select Light-Weight and Accurate Features for Real-Time Activity Recognition on Smartphones

    Directory of Open Access Journals (Sweden)

    Seok-Won Lee

    2013-09-01

    Full Text Available Smartphone-based activity recognition (SP-AR recognizes users’ activities using the embedded accelerometer sensor. Only a small number of previous works can be classified as online systems, i.e., the whole process (pre-processing, feature extraction, and classification is performed on the device. Most of these online systems use either a high sampling rate (SR or long data-window (DW to achieve high accuracy, resulting in short battery life or delayed system response, respectively. This paper introduces a real-time/online SP-AR system that solves this problem. Exploratory data analysis was performed on acceleration signals of 6 activities, collected from 30 subjects, to show that these signals are generated by an autoregressive (AR process, and an accurate AR-model in this case can be built using a low SR (20 Hz and a small DW (3 s. The high within class variance resulting from placing the phone at different positions was reduced using kernel discriminant analysis to achieve position-independent recognition. Neural networks were used as classifiers. Unlike previous works, true subject-independent evaluation was performed, where 10 new subjects evaluated the system at their homes for 1 week. The results show that our features outperformed three commonly used features by 40% in terms of accuracy for the given SR and DW.

  4. Species-specific engagement of human nucleotide oligomerization domain 2 (NOD)2 and Toll-like receptor (TLR) signalling upon intracellular bacterial infection

    DEFF Research Database (Denmark)

    Salem, M; Seidelin, J B; Eickhardt-Dalbøge, Steffen Robert;

    2015-01-01

    of MDP and further to determine the role of NOD2 gene variants for the bacterial recognition in CD. The response pattern to A-MDP, G-MDP, Mycobacterium segmatis (expressing mainly G-MDP) and M. segmatisΔnamH (expressing A-MDP), Listeria monocytogenes (LM) (an A-MDP-containing bacteria) and M. avium....... NOD2 mutations resulted in a low tumour necrosis factor (TNF)-α protein secretion following stimulation with LM. Contrary to this, TNF-α levels were unchanged upon MAP stimulation regardless of NOD2 genotype and MAP solely activated NOD2- and Toll-like receptor (TLRs)-pathway with an enhanced...... production of interleukin (IL)-1β and IL-10. In conclusion, the results indicate that CD-associated NOD2 deficiencies might affect the response towards a broader array of commensal and pathogenic bacteria expressing A-MDP, whereas they attenuate the role of mycobacteria in the pathogenesis of CD....

  5. Forensic speaker recognition

    NARCIS (Netherlands)

    Meuwly, Didier

    2009-01-01

    The aim of forensic speaker recognition is to establish links between individuals and criminal activities, through audio speech recordings. This field is multidisciplinary, combining predominantly phonetics, linguistics, speech signal processing, and forensic statistics. On these bases, expert-based

  6. Calix[8]arene functionalized single-walled carbon nanohorns for dual-signalling electrochemical sensing of aconitine based on competitive host-guest recognition.

    Science.gov (United States)

    Yang, Long; Ran, Xin; Cai, Le; Li, Yucong; Zhao, Hui; Li, Can-Peng

    2016-09-15

    A dual-signalling electrochemical approach has been developed towards aconitine based on competitive host-guest interaction by selecting methylene blue (MB) and p-sulfonated calix[8]arene functionalized single-walled carbon nanohorns (SCX8-SWCNHs) as the "reporter pair". Upon the presence of aconitine to the performed SCX8-SWCNHs·MB complex, the MB molecules are displaced by aconitine. This results in a decreased oxidation peak current of MB and the appearance of an oxidation peak of aconitine, and the changes of these signals correlate linearly with the concentration of aconitine. A linear response range of 1.00-10.00μM for aconitine with a low detection limit of 0.18μM (S/N=3) was obtained by using the proposed method. This method could be successfully utilized to detect aconitine in serum samples. This dual-signalling sensor can provide more sensitive target recognition and will have important applications in the sensitive and selective electrochemical detection of aconitine. PMID:27135940

  7. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-07-01

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and

  8. A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation.

    Science.gov (United States)

    Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

    2013-08-21

    A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 10(10). The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.

  9. MyD88-deficient Hydra reveal an ancient function of TLR signaling in sensing bacterial colonizers

    OpenAIRE

    Franzenburg, Sören; Fraune, Sebastian; Künzel, Sven; Baines, John F; Domazet-Lošo, Tomislav; Bosch, Thomas C. G.

    2012-01-01

    Toll-like receptor (TLR) signaling is one of the most important signaling cascades of the innate immune system of vertebrates. Studies in invertebrates have focused on the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans, and there is little information regarding the evolutionary origin and ancestral function of TLR signaling. In Drosophila, members of the Toll-like receptor family are involved in both embryonic development and innate immunity. In C. elegans, a clear ...

  10. TLR2 signaling decreases transmission of Streptococcus pneumoniae by limiting bacterial shedding in an infant mouse Influenza A co-infection model.

    Directory of Open Access Journals (Sweden)

    Aimee L Richard

    2014-08-01

    Full Text Available While the importance of transmission of pathogens is widely accepted, there is currently little mechanistic understanding of this process. Nasal carriage of Streptococcus pneumoniae (the pneumococcus is common in humans, especially in early childhood, and is a prerequisite for the development of disease and transmission among hosts. In this study, we adapted an infant mouse model to elucidate host determinants of transmission of S. pneumoniae from inoculated index mice to uninfected contact mice. In the context of co-infection with influenza A virus, the pneumococcus was transmitted among wildtype littermates, with approximately half of the contact mice acquiring colonization. Mice deficient for TLR2 were colonized to a similar density but transmitted S. pneumoniae more efficiently (100% transmission than wildtype animals and showed decreased expression of interferon α and higher viral titers. The greater viral burden in tlr2-/- mice correlated with heightened inflammation, and was responsible for an increase in bacterial shedding from the mouse nose. The role of TLR2 signaling was confirmed by intranasal treatment of wildtype mice with the agonist Pam3Cys, which decreased inflammation and reduced bacterial shedding and transmission. Taken together, these results suggest that the innate immune response to influenza virus promotes bacterial shedding, allowing the bacteria to transit from host to host. These findings provide insight into the role of host factors in the increased pneumococcal carriage rates seen during flu season and contribute to our overall understanding of pathogen transmission.

  11. Improved signal recognition for interphase fluorescent in-situ hybridization using a non-ionic detergent (NP-40) pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.M.; Day-Salvatore, D.L.; Sciorra, L.J. [Univ. of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick, NJ (United States)] [and others

    1994-09-01

    We have reported that the non-ionic detergent ethylphenolpoly (ethyleneglycolether)x known as Noniet-P40 (Shell International Petroleum) can gently disrupt cell membranes, resulting in cells with varying degrees of free chromatin release. The extent of this phenomena is dependent upon the concentration of NP-40 and the detergent`s exposure time to the cells. Treated cells can range from halos of DNA around the cells to fully extended free chromatin configurations. We have demonstrated that these treated cells are excellent targets for many different fluorescently labelled probes used for in situ hybridization studies. Recently, we have compared NP-40 harvested lymphocytes with normally harvested cells to see if we could improve upon the number of cells showing discreet signals in interphase fluorescent in situ hybridization. Preliminary work has shown that using a trisomy 21 cell line, one can get a statistically significant improvement with NP-40 pretreatment cells over control levels, in the number of cells having three discreet signals in interphase {open_quotes}FISH{close_quotes}. Such a pretreatment is simple to perform and may be of value when the number of cells available for analysis is low, as in the search for fetal cells from maternal circulation.

  12. Evaluating faces on trustworthiness: an extension of systems for recognition of emotions signaling approach/avoidance behaviors.

    Science.gov (United States)

    Todorov, Alexander

    2008-03-01

    People routinely make various trait judgments from facial appearance, and such judgments affect important social outcomes. These judgments are highly correlated with each other, reflecting the fact that valence evaluation permeates trait judgments from faces. Trustworthiness judgments best approximate this evaluation, consistent with evidence about the involvement of the amygdala in the implicit evaluation of face trustworthiness. Based on computer modeling and behavioral experiments, I argue that face evaluation is an extension of functionally adaptive systems for understanding the communicative meaning of emotional expressions. Specifically, in the absence of diagnostic emotional cues, trustworthiness judgments are an attempt to infer behavioral intentions signaling approach/avoidance behaviors. Correspondingly, these judgments are derived from facial features that resemble emotional expressions signaling such behaviors: happiness and anger for the positive and negative ends of the trustworthiness continuum, respectively. The emotion overgeneralization hypothesis can explain highly efficient but not necessarily accurate trait judgments from faces, a pattern that appears puzzling from an evolutionary point of view and also generates novel predictions about brain responses to faces. Specifically, this hypothesis predicts a nonlinear response in the amygdala to face trustworthiness, confirmed in functional magnetic resonance imaging (fMRI) studies, and dissociations between processing of facial identity and face evaluation, confirmed in studies with developmental prosopagnosics. I conclude with some methodological implications for the study of face evaluation, focusing on the advantages of formally modeling representation of faces on social dimensions.

  13. Gaseous 3-pentanol primes plant immunity against a bacterial speck pathogen, Pseudomonas syringae pv. tomato via salicylic acid and jasmonic acid-dependent signaling pathways in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Geun Cheol eSong

    2015-10-01

    Full Text Available 3-Pentanol is an active organic compound produced by plants and is a component of emitted insect sex pheromones. A previous study reported that drench application of 3-pentanol elicited plant immunity against microbial pathogens and an insect pest in crop plants. Here, we evaluated whether 3-pentanol and the derivatives 1-pentanol and 2-pentanol induced plant systemic resistance using the in vitro I-plate system. Exposure of Arabidopsis seedlings to 10 M and 100 nM 3-pentanol evaporate elicited an immune response to Pseudomonas syringae pv. tomato DC3000. We performed quantitative real-time PCR to investigate the 3-pentanol-mediated Arabidopsis immune responses by determining Pathogenesis-Related (PR gene expression levels associated with defense signaling through SA, JA, and ethylene signaling pathways. The results show that exposure to 3-pentanol and subsequent pathogen challenge upregulated PDF1.2 and PR1 expression. Selected Arabidopsis mutants confirmed that the 3-pentanol-mediated immune response involved salicylic acid (SA and jasmonic acid (JA signaling pathways and the NPR1 gene. Taken together, this study indicates that gaseous 3-pentanol triggers induced resistance in Arabidopsis by priming SA and JA signaling pathways. To our knowledge, this is the first report that a volatile compound of an insect sex pheromone triggers plant systemic resistance against a bacterial pathogen.

  14. The bacterial effector HopX1 targets JAZ transcriptional repressors to activate jasmonate signaling and promote infection in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Selena Gimenez-Ibanez

    2014-02-01

    Full Text Available Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR, which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile. Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome.

  15. 电磁声发射的实验与信号识别研究%Signal Recognition and Experiment for Electromagnetically Induced Acoustic Emission

    Institute of Scientific and Technical Information of China (English)

    张闯; 刘素贞; 杨庆新; 金亮; 杨素梅

    2012-01-01

    Electromagnetically induced acoustic emission(EMAE) technique is a new nondestructive testing(NDT).It does nondestructive detection with the effect of dynamic electromagnetic loading to generate a stress field stimulating stress waves from the defects.The principle and implementation procedure of the EMAE is analyzed.It adopts the neural network recognition method based on wave analysis.The characteristic parameters of EMAE signal are extracted using wavelet packet transform.The recognition system of back-propagation(BP) network consists of 10 input elements,18 hidden elements and single output.In order to overcome the shortcoming of low constringency speed,this paper proposes a kind of neural network recognition with adaptive number of neurons on the input layer method.The experiment results show it can identify the crack in the metal plate quickly and accurately.%电磁声发射技术是一种新型的无损检测技术,通过对金属部件进行电磁加载会在裂纹处激发出声发射信号,并利用这一现象实现对金属材料的无损检测。本文分析了电磁声发射技术的基本原理与实现过程,采用一种基于波形分析的神经网络模式识别方法,利用小波包变换提取出电磁声发射信号波形的识别特征参数,建立了由10个输入单元、18个隐含单元和单输出组成的人工神经网络识别系统。为了克服BP神经网络收敛速度慢的缺点,提出了一种输入单元数目可变的神经网络改进方法,实验表明该系统能够对有无裂纹板进行快速、准确的识别。

  16. IL-1RI (interleukin-1 receptor type I signalling is essential for host defence and hemichannel activity during acute central nervous system bacterial infection

    Directory of Open Access Journals (Sweden)

    Tammy Kielian

    2012-04-01

    Full Text Available Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1 response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood–brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I KO (knockout animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared with WT (wild-type animals. Loss of IL-1RI signalling also dampened the expression of select cytokines and chemokines, concomitant with significant reductions in neutrophil and macrophage infiltrates into the brain. In addition, the opening of astrocyte hemichannels during acute infection was shown to be dependent on IL-1RI activity. Collectively, these results demonstrate that IL-1RI signalling plays a pivotal role in the genesis of immune responses during the acute stage of brain abscess development through S. aureus containment, inflammatory mediator production, peripheral immune cell recruitment, and regulation of astrocyte hemichannel activity. Taken in the context of previous studies with MyD88 (myeloid differentiation primary response gene 88 and TLR2 (Toll-like receptor 2 KO animals, the current report advances our understanding of MyD88-dependent cascades and implicates IL-1RI signalling as a major antimicrobial effector pathway during acute brain-abscess formation.

  17. Galectin-9 Signaling through TIM-3 Is Involved in Neutrophil-Mediated Gram-Negative Bacterial Killing: An Effect Abrogated within the Cystic Fibrosis Lung

    Science.gov (United States)

    Vega-Carrascal, Isabel; Bergin, David A.; McElvaney, Oliver J.; McCarthy, Cormac; Banville, Nessa; Pohl, Kerstin; Hirashima, Mitsuomi; Kuchroo, Vijay K.; Reeves, Emer P.; McElvaney, Noel G.

    2016-01-01

    The T cell Ig and mucin domain–containing molecule (TIM) family of receptors have emerged as potential therapeutic targets to correct abnormal immune function in chronic inflammatory conditions. TIM-3 serves as a functional receptor in structural cells of the airways and via the ligand galectin-9 (Gal-9) can modulate the inflammatory response. The aim of this study was to investigate TIM-3 expression and function in neutrophils, focusing on its potential role in cystic fibrosis (CF) lung disease. Results revealed that TIM-3 mRNA and protein expression values of circulating neutrophils were equal between healthy controls (n = 20) and people with CF (n = 26). TIM-3 was detected on resting neutrophil membranes by FACS analysis, and expression levels significantly increased post IL-8 or TNF-α exposure (p < 0.05). Our data suggest a novel role for TIM-3/Gal-9 signaling involving modulation of cytosolic calcium levels. Via TIM-3 interaction, Gal-9 induced neutrophil degranulation and primed the cell for enhanced NADPH oxidase activity. Killing of Pseudomonas aeruginosa was significantly increased upon bacterial opsonization with Gal-9 (p < 0.05), an effect abrogated by blockade of TIM-3 receptors. This mechanism appeared to be Gram-negative bacteria specific and mediated via Gal-9/ LPS binding. Additionally, we have demonstrated that neutrophil TIM-3/Gal-9 signaling is perturbed in the CF airways due to proteolytic degradation of the receptor. In conclusion, results suggest a novel neutrophil defect potentially contributing to the defective bacterial clearance observed in the CF airways and suggest that manipulation of the TIM-3 signaling pathway may be of therapeutic value in CF, preferably in conjunction with antiprotease treatment. PMID:24477913

  18. Studying the Mechanism of Phototransformation of Light Signal by Various Mammal and Bacterial Photoreceptor Pigments  Rhodopsin, Iodopsin and Bacteriorhodopsin

    Directory of Open Access Journals (Sweden)

    Ignat Ignatov

    2015-06-01

    Full Text Available This review article outlines the structure and function of mammal and bacterial photoreceptor pigments (rhodopsin, iodopsin, bacteriorhodopsin and their aspects of bio-nanotechnological usage. On an example of bacteriorhodopsin is described the method of its isolation from purple membranes of photo-organotrophic halobacterium Halobacterium halobium ET 1001 by cellular autolysis by distilled water, processing of bacterial biomass by ultrasound at 22 KHz, alcohol extraction of low and high-weight molecular impurities, cellular RNA, carotenoids and lipids, the solubilization with 0,5 % (w/v SDS-Na and subsequent fractionation by methanol and gel filtration chromatography on Sephadex G-200 Column balanced with 0,09 M Tris-buffer (pH = 8,35 with 0,1 % (w/v SDS-Na and 2,5 mM EDTA. Within the framework of the research the mechanism of color perception by the visual retina analyzer having the ability to analyze certain ranges of the optical spectrum as colors, was studied along with an analysis of the additive mixing of two or more colors. It was shown that at the mixing of electromagnetic waves with different wavelengths, the visual analyzer perceives them as the separate or average wave length corresponding to the mixing color.

  19. Structural Basis for Fc[gamma]RIIa Recognition of Human IgG and Formation of Inflammatory Signaling Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Ramsland, Paul A.; Farrugia, William; Bradford, Tessa M.; Sardjono, Caroline Tan; Esparon, Sandra; Trist, Halina M.; Powell, Maree S.; Tan, Peck Szee; Cendron, Angela C.; Wines, Bruce D.; Scott, Andrew M.; Hogarth, P. Mark (Burnet); (Monash); (LICR); (Melbourne)

    2011-09-20

    The interaction of Abs with their specific FcRs is of primary importance in host immune effector systems involved in infection and inflammation, and are the target for immune evasion by pathogens. Fc{gamma}RIIa is a unique and the most widespread activating FcR in humans that through avid binding of immune complexes potently triggers inflammation. Polymorphisms of Fc{gamma}RIIa (high responder/low responder [HR/LR]) are linked to susceptibility to infections, autoimmune diseases, and the efficacy of therapeutic Abs. In this article, we define the three-dimensional structure of the complex between the HR (arginine, R134) allele of Fc{gamma}RIIa (Fc{gamma}RIIa-HR) and the Fc region of a humanized IgG1 Ab, hu3S193. The structure suggests how the HR/LR polymorphism may influence Fc{gamma}RIIa interactions with different IgG subclasses and glycoforms. In addition, mutagenesis defined the basis of the epitopes detected by FcR blocking mAbs specific for Fc{gamma}RIIa (IV.3), Fc{gamma}RIIb (X63-21), and a pan Fc{gamma}RII Ab (8.7). The epitopes detected by these Abs are distinct, but all overlap with residues defined by crystallography to contact IgG. Finally, crystal structures of LR (histidine, H134) allele of Fc{gamma}RIIa and Fc{gamma}RIIa-HR reveal two distinct receptor dimers that may represent quaternary states on the cell surface. A model is presented whereby a dimer of Fc{gamma}RIIa-HR binds Ag-Ab complexes in an arrangement that possibly occurs on the cell membrane as part of a larger signaling assembly.

  20. Genetic and metabolic signals during acute enteric bacterial infection alter the microbiota and drive progression to chronic inflammatory disease

    Energy Technology Data Exchange (ETDEWEB)

    Kamdar, Karishma; Khakpour, Samira; Chen, Jingyu; Leone, Vanessa; Brulc, Jennifer; Mangatu, Thomas; Antonopoulos, Dionysios A.; Chang, Eugene B; Kahn, Stacy A.; Kirschner, Barbara S; Young, Glenn; DePaolo, R. William

    2016-01-13

    Chronic inflammatory disorders are thought to arise due to an interplay between predisposing host genetics and environmental factors. For example, the onset of inflammatory bowel disease is associated with enteric proteobacterial infection, yet the mechanistic basis for this association is unclear. We have shown previously that genetic defiency in TLR1 promotes acute enteric infection by the proteobacteria Yersinia enterocolitica. Examining that model further, we uncovered an altered cellular immune response that promotes the recruitment of neutrophils which in turn increases metabolism of the respiratory electron acceptor tetrathionate by Yersinia. These events drive permanent alterations in anti-commensal immunity, microbiota composition, and chronic inflammation, which persist long after Yersinia clearence. Deletion of the bacterial genes involved in tetrathionate respiration or treatment using targeted probiotics could prevent microbiota alterations and inflammation. Thus, acute infection can drive long term immune and microbiota alterations leading to chronic inflammatory disease in genetically predisposed individuals.

  1. 基于熵和PSO优化SVM的肌电信号跌倒识别%Fall Recognition Based on EMG Signal Entropy and PSO-SVM

    Institute of Scientific and Technical Information of China (English)

    武昊; 席旭刚; 罗志增

    2015-01-01

    跌倒对老年人的健康构成严重危害,设计了一种基于肌电信号的跌倒识别方法,可用于跌倒检测报警。该方法首先对表面肌电动作信号进行小波包分解,再依据信号特征选取信号的低频分量并重构,计算其排列组合熵,最后以4路肌电信号对应的排列组合熵组成的特征向量输入SVM进行模式识别并采用粒子群算法对SVM中惩罚参数c和核函数参数g进行优化,对8种动作进行识别实验,跌倒识别率88%,特异度98.3%,平均识别率97.0%,优于网格法和遗传算法支持向量机(GA-SVM)的参数优化,具有较强的鲁棒性和抗干扰能力。%A new fall detection method was designed for fall alarm based on sEMG. Firstly,the sEMG signals are de⁃composed into subspaces with wavelet packet. Then,depending on the signal characteristics,signals of low-frequen⁃cy component were recombined to calculate the permutation entropy. Finally,the SVM method was used to recog⁃nize eight actions according to the permutation entropy of four sEMG signals,and the particle swarm optimization was used to optimize punishment parameter c and nuclear parameter g . The result shows fall sensitivity,fall spec⁃ificity,the average recognition rate were 88%,98.3%,97.0%,better than the gird method and genetic algorithm pa⁃rameters optimization. The method has strong robustness and noise immunity.

  2. Type I interferon production during herpes simplex virus infection is controlled by cell-type-specific viral recognition through Toll-like receptor 9, the mitochondrial antiviral signaling protein pathway, and novel recognition systems

    DEFF Research Database (Denmark)

    Rasmussen, Simon Brandtoft; Sørensen, Louise Nørgaard; Malmgaard, Lene;

    2007-01-01

    Recognition of viruses by germ line-encoded pattern recognition receptors of the innate immune system is essential for rapid production of type I interferon (IFN) and early antiviral defense. We investigated the mechanisms of viral recognition governing production of type I IFN during herpes....... In conventional DCs, the IFN response occurred independently of viral replication but was dependent on viral entry. Moreover, using a HSV-1 UL15 mutant, which fails to package viral DNA into the virion, we found that entry-dependent IFN induction also required the presence of viral genomic DNA. In macrophages...

  3. PtdIns4P recognition by Vps74/GOLPH3 links PtdIns 4-kinase signaling to retrograde Golgi trafficking

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Christopher S.; Schmitz, Karl R.; Bessman, Nicholas J.; Setty, Thanuja Gangi; Ferguson, Kathryn M.; Burd, Christopher G.; (UPENN-MED)

    2010-02-11

    Targeting and retention of resident integral membrane proteins of the Golgi apparatus underly the function of the Golgi in glycoprotein and glycolipid processing and sorting. In yeast, steady-state Golgi localization of multiple mannosyltransferases requires recognition of their cytosolic domains by the peripheral Golgi membrane protein Vps74, an orthologue of human GOLPH3/GPP34/GMx33/MIDAS (mitochondrial DNA absence sensitive factor). We show that targeting of Vps74 and GOLPH3 to the Golgi apparatus requires ongoing synthesis of phosphatidylinositol (PtdIns) 4-phosphate (PtdIns4P) by the Pik1 PtdIns 4-kinase and that modulation of the levels and cellular location of PtdIns4P leads to mislocalization of these proteins. Vps74 and GOLPH3 bind specifically to PtdIns4P, and a sulfate ion in a crystal structure of GOLPH3 indicates a possible phosphoinositide-binding site that is conserved in Vps74. Alterations in this site abolish phosphoinositide binding in vitro and Vps74 function in vivo. These results implicate Pik1 signaling in retention of Golgi-resident proteins via Vps74 and show that GOLPH3 family proteins are effectors of Golgi PtdIns 4-kinases.

  4. Spectral feature extraction of EEG signals and pattern recognition during mental tasks of 2-D cursor movements for BCI using SVM and ANN.

    Science.gov (United States)

    Bascil, M Serdar; Tesneli, Ahmet Y; Temurtas, Feyzullah

    2016-09-01

    Brain computer interface (BCI) is a new communication way between man and machine. It identifies mental task patterns stored in electroencephalogram (EEG). So, it extracts brain electrical activities recorded by EEG and transforms them machine control commands. The main goal of BCI is to make available assistive environmental devices for paralyzed people such as computers and makes their life easier. This study deals with feature extraction and mental task pattern recognition on 2-D cursor control from EEG as offline analysis approach. The hemispherical power density changes are computed and compared on alpha-beta frequency bands with only mental imagination of cursor movements. First of all, power spectral density (PSD) features of EEG signals are extracted and high dimensional data reduced by principle component analysis (PCA) and independent component analysis (ICA) which are statistical algorithms. In the last stage, all features are classified with two types of support vector machine (SVM) which are linear and least squares (LS-SVM) and three different artificial neural network (ANN) structures which are learning vector quantization (LVQ), multilayer neural network (MLNN) and probabilistic neural network (PNN) and mental task patterns are successfully identified via k-fold cross validation technique. PMID:27376723

  5. YGL9, encoding the putative chloroplast signal recognition particle 43 kDa protein in rice, is involved in chloroplast development

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-wei; LI Yun-feng; LING Ying-hua; SANG Xian-chun; HE Guang-hua; ZHANG Tian-quan; XING Ya-di; ZENG Xiao-qin; WANG Ling; LIU Zhong-xian; SHI Jun-qiong; ZHU Xiao-yan; MA Ling

    2016-01-01

    The nuclear-encoded light-harvesting chlorophyla/b-binding proteins (LHCPs) are speciifcaly translocated from the stroma into the thylakoid membrane through the chloroplast signal recognition particle (cpSRP) pathway. The cpSRP is composed of a cpSRP43 protein and a cpSRP54 protein, and it forms a soluble transit complex with LHCP in the chloroplast stroma. Here, we identiifed theYGL9gene that is predicted to encode the probable rice cpSRP43 protein from a rice yelow-green leaf mutant. A phylogenetic tree showed that an important conserved protein family, cpSRP43, is present in almost al green photosynthetic organisms such as higher plants and green algae. Sequence analysis showed that YGL9 comprises a chloroplast transit peptide, three chromodomains and four ankyrin repeats, and the chromodomains and ankyrin repeats are probably involved in protein-protein interactions. Subcelular localization showed that YGL9 is localized in the chloroplast. Expression pattern analysis indicated thatYGL9is mainly expressed in green leaf sheaths and leaves. Quantitative real-time PCR analysis showed that the expression levels of genes associated with pigment metabolism, chloroplast development and photosynthesis were distinctly affected in theygl9mutant. These results indicated thatYGL9 is possibly involved in pigment metabolism, chloroplast development and photosynthesis in rice.

  6. Pattern recognition receptor signaling in human dendritic cells is enhanced by ICOS ligand and modulated by the Crohn's disease ICOSLG risk allele.

    Science.gov (United States)

    Hedl, Matija; Lahiri, Amit; Ning, Kaida; Cho, Judy H; Abraham, Clara

    2014-05-15

    Inflammatory bowel disease (IBD) is characterized by dysregulated intestinal immune homeostasis and cytokine secretion. Multiple loci are associated with IBD, but a functional explanation is missing for most. Here we found that pattern-recognition receptor (PRR)-induced cytokine secretion was diminished in human monocyte-derived dendritic cells (MDDC) from rs7282490 ICOSLG GG risk carriers. Homotypic interactions between the costimulatory molecule ICOS and the ICOS ligand on MDDCs amplified nucleotide-binding oligomerization domain 2 (NOD2)-initiated cytokine secretion. This amplification required arginine residues in the ICOSL cytoplasmic tail that recruited the adaptor protein RACK1 and the kinases PKC and JNK leading to PKC, MAPK, and NF-κB activation. MDDC from rs7282490 GG risk-carriers had reduced ICOSL expression and PRR-initiated signaling and this loss-of-function ICOSLG risk allele associated with an ileal Crohn's disease phenotype, similar to polymorphisms in NOD2. Taken together, ICOSL amplifies PRR-initiated outcomes, which might contribute to immune homeostasis.

  7. The chloroplast signal recognition particle (CpSRP) pathway as a tool to minimize chlorophyll antenna size and maximize photosynthetic productivity.

    Science.gov (United States)

    Kirst, Henning; Melis, Anastasios

    2014-01-01

    The concept of the Truncated Light-harvesting chlorophyll Antenna (TLA) size, as a tool by which to maximize sunlight utilization and photosynthetic productivity in microalgal mass cultures or high-density plant canopies, is discussed. TLA technology is known to improve sunlight-to-product energy conversion efficiencies and is hereby exemplified by photosynthetic productivity estimates of wild type and a TLA strain under simulated mass culture conditions. Recent advances in the generation of TLA-type mutants by targeting genes of the chloroplast signal-recognition particle (CpSRP) pathway, affecting the thylakoid membrane assembly of light-harvesting proteins, are also summarized. Two distinct CpSRP assembly pathways are recognized, one entailing post-translational, the other a co-translational mechanism. Differences between the post-translational and co-translational integration mechanisms are outlined, as these pertain to the CpSRP-mediated assembly of thylakoid membrane protein complexes in higher plants and green microalgae. The applicability of the CpSRP pathway genes in efforts to generate TLA-type strains with enhanced solar energy conversion efficiency in photosynthesis is evaluated.

  8. A Cell Phone Positioning Method Based on the Intelligent Received Signal Strength Pattern Recognition in GSM Network for Implementing Mobile Advertisement Services

    Directory of Open Access Journals (Sweden)

    M. F Sabahi

    2013-06-01

    Full Text Available Cellular positioning methods in urban environments suffer from a significant error due to multipath and fading phenomena. In this paper, regarding the implementation location-based services, one pattern recognition positioning method based on the signal strength is presented, which provides proper results in urban areas. Although many works have been done in this field, the main challenge is to create and to update the database and heavy calculation to estimate the position .In this paper, some practical and intelligent solutions for overcoming the mentioned problems, enhancing the accuracy and reducing the computational load of this positioning method are presented. Specially, some intelligent filtering methods are presented for reducing the search region in the database and also increasing the accuracy of position estimation. Real measurements obtained in Isfahan, illustrate the high accuracy of the proposed techniques. In addition, an advertising service based on the proposed method is presented. User’s interest and local time is considered as well as him/her position for enhancing the efficiency of the mentioned service.

  9. Evaluating music emotion recognition

    DEFF Research Database (Denmark)

    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 system, and conclude with recommendations....

  10. Burkholderia pseudomallei Capsule Exacerbates Respiratory Melioidosis but Does Not Afford Protection against Antimicrobial Signaling or Bacterial Killing in Human Olfactory Ensheathing Cells.

    Science.gov (United States)

    Dando, Samantha J; Ipe, Deepak S; Batzloff, Michael; Sullivan, Matthew J; Crossman, David K; Crowley, Michael; Strong, Emily; Kyan, Stephanie; Leclercq, Sophie Y; Ekberg, Jenny A K; St John, James; Beacham, Ifor R; Ulett, Glen C

    2016-07-01

    Melioidosis, caused by the bacterium Burkholderia pseudomallei, is an often severe infection that regularly involves respiratory disease following inhalation exposure. Intranasal (i.n.) inoculation of mice represents an experimental approach used to study the contributions of bacterial capsular polysaccharide I (CPS I) to virulence during acute disease. We used aerosol delivery of B. pseudomallei to establish respiratory infection in mice and studied CPS I in the context of innate immune responses. CPS I improved B. pseudomallei survival in vivo and triggered multiple cytokine responses, neutrophil infiltration, and acute inflammatory histopathology in the spleen, liver, nasal-associated lymphoid tissue, and olfactory mucosa (OM). To further explore the role of the OM response to B. pseudomallei infection, we infected human olfactory ensheathing cells (OECs) in vitro and measured bacterial invasion and the cytokine responses induced following infection. Human OECs killed >90% of the B. pseudomallei in a CPS I-independent manner and exhibited an antibacterial cytokine response comprising granulocyte colony-stimulating factor, tumor necrosis factor alpha, and several regulatory cytokines. In-depth genome-wide transcriptomic profiling of the OEC response by RNA-Seq revealed a network of signaling pathways activated in OECs following infection involving a novel group of 378 genes that encode biological pathways controlling cellular movement, inflammation, immunological disease, and molecular transport. This represents the first antimicrobial program to be described in human OECs and establishes the extensive transcriptional defense network accessible in these cells. Collectively, these findings show a role for CPS I in B. pseudomallei survival in vivo following inhalation infection and the antibacterial signaling network that exists in human OM and OECs.

  11. Burkholderia pseudomallei Capsule Exacerbates Respiratory Melioidosis but Does Not Afford Protection against Antimicrobial Signaling or Bacterial Killing in Human Olfactory Ensheathing Cells.

    Science.gov (United States)

    Dando, Samantha J; Ipe, Deepak S; Batzloff, Michael; Sullivan, Matthew J; Crossman, David K; Crowley, Michael; Strong, Emily; Kyan, Stephanie; Leclercq, Sophie Y; Ekberg, Jenny A K; St John, James; Beacham, Ifor R; Ulett, Glen C

    2016-07-01

    Melioidosis, caused by the bacterium Burkholderia pseudomallei, is an often severe infection that regularly involves respiratory disease following inhalation exposure. Intranasal (i.n.) inoculation of mice represents an experimental approach used to study the contributions of bacterial capsular polysaccharide I (CPS I) to virulence during acute disease. We used aerosol delivery of B. pseudomallei to establish respiratory infection in mice and studied CPS I in the context of innate immune responses. CPS I improved B. pseudomallei survival in vivo and triggered multiple cytokine responses, neutrophil infiltration, and acute inflammatory histopathology in the spleen, liver, nasal-associated lymphoid tissue, and olfactory mucosa (OM). To further explore the role of the OM response to B. pseudomallei infection, we infected human olfactory ensheathing cells (OECs) in vitro and measured bacterial invasion and the cytokine responses induced following infection. Human OECs killed >90% of the B. pseudomallei in a CPS I-independent manner and exhibited an antibacterial cytokine response comprising granulocyte colony-stimulating factor, tumor necrosis factor alpha, and several regulatory cytokines. In-depth genome-wide transcriptomic profiling of the OEC response by RNA-Seq revealed a network of signaling pathways activated in OECs following infection involving a novel group of 378 genes that encode biological pathways controlling cellular movement, inflammation, immunological disease, and molecular transport. This represents the first antimicrobial program to be described in human OECs and establishes the extensive transcriptional defense network accessible in these cells. Collectively, these findings show a role for CPS I in B. pseudomallei survival in vivo following inhalation infection and the antibacterial signaling network that exists in human OM and OECs. PMID:27091931

  12. 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

  13. Inhibition of Nod2 signaling and target gene expression by curcumin

    Science.gov (United States)

    Nod2 is an intracellular pattern recognition receptor that detects a conserved moiety of bacterial peptidoglycan and subsequently activates proinflammatory signaling pathways. Mutations in Nod2 have been implicated to be linked to inflammatory granulomatous disorders, such as Crohn’s disease and Bla...

  14. The pepper GNA-related lectin and PAN domain protein gene, CaGLP1, is required for plant cell death and defense signaling during bacterial infection.

    Science.gov (United States)

    Kim, Nak Hyun; Lee, Dong Hyuk; Choi, Du Seok; Hwang, Byung Kook

    2015-12-01

    Carbohydrate-binding proteins, commonly referred to as lectins or agglutinins, function in defense responses to microbial pathogens. Pepper (Capsicum annuum) GNA-related lectin and PAN-domain protein gene CaGLP1 was isolated and functionally characterized from pepper leaves infected with Xanthomonas campestris pv. vesicatoria (Xcv). CaGLP1 contained an amine-terminus prokaryotic membrane lipoprotein lipid attachment site, a Galanthus nivalis agglutinin (GNA)-related lectin domain responsible for the recognition of high-mannose N-glycans, and a carboxyl-terminus PAN/apple domain. RNA gel blot and immunoblot analyses determined that CaGLP1 was strongly induced in pepper by compatible and incompatible Xcv infection. CaGLP1 protein localized primarily to the plasma membrane and exhibited mannose-binding specificity. CaGLP1-silenced pepper plants were more susceptible to compatible or incompatible Xcv infection compared with that of non-silenced control plants. CaGLP1 silencing in pepper leaves did not accumulate H2O2 and induce cell death during incompatible Xcv infection. Defense-related CaDEF1 (defensin) gene expression was significantly reduced in CaGLP1-silenced pepper plants. CaGLP1-overexpression in Arabidopsis thaliana enhanced resistance to Pseudomonas syringae pv. tomato. Defense-related AtPDF1.2 expression was elevated in CaGLP1-overexpression lines. Together, these results suggest that CaGLP1 is required for plant cell death and defense responses through the reactive oxygen species burst and downstream defense-related gene expression in response to bacterial pathogen challenge.

  15. Hallucinogenic 5-HT2AR agonists LSD and DOI enhance dopamine D2R protomer recognition and signaling of D2-5-HT2A heteroreceptor complexes.

    Science.gov (United States)

    Borroto-Escuela, Dasiel O; Romero-Fernandez, Wilber; Narvaez, Manuel; Oflijan, Julia; Agnati, Luigi F; Fuxe, Kjell

    2014-01-01

    Dopamine D2LR-serotonin 5-HT2AR heteromers were demonstrated in HEK293 cells after cotransfection of the two receptors and shown to have bidirectional receptor-receptor interactions. In the current study the existence of D2L-5-HT2A heteroreceptor complexes was demonstrated also in discrete regions of the ventral and dorsal striatum with in situ proximity ligation assays (PLA). The hallucinogenic 5-HT2AR agonists LSD and DOI but not the standard 5-HT2AR agonist TCB2 and 5-HT significantly increased the density of D2like antagonist (3)H-raclopride binding sites and significantly reduced the pKiH values of the high affinity D2R agonist binding sites in (3)H-raclopride/DA competition experiments. Similar results were obtained in HEK293 cells and in ventral striatum. The effects of the hallucinogenic 5-HT2AR agonists on D2R density and affinity were blocked by the 5-HT2A antagonist ketanserin. In a forskolin-induced CRE-luciferase reporter gene assay using cotransfected but not D2R singly transfected HEK293 cells DOI and LSD but not TCB2 significantly enhanced the D2LR agonist quinpirole induced inhibition of CRE-luciferase activity. Haloperidol blocked the effects of both quinpirole alone and the enhancing actions of DOI and LSD while ketanserin only blocked the enhancing actions of DOI and LSD. The mechanism for the allosteric enhancement of the D2R protomer recognition and signalling observed is likely mediated by a biased agonist action of the hallucinogenic 5-HT2AR agonists at the orthosteric site of the 5-HT2AR protomer. This mechanism may contribute to the psychotic actions of LSD and DOI and the D2-5-HT2A heteroreceptor complex may thus be a target for the psychotic actions of hallunicogenic 5-HT2A agonists.

  16. Detection of boiling by Piety's on-line PSD-pattern recognition algorithm applied to neutron noise signals in the SAPHIR reactor

    International Nuclear Information System (INIS)

    A partial blockage of the cooling channels of a fuel element in a swimming pool reactor could lead to vapour generation and to burn-out. To detect such anomalies, a pattern recognition algorithm based on power spectra density (PSD) proposed by Piety was further developed and implemented on a PDP 11/23 for on-line applications. This algorithm identifies anomalies by measuring the PSD on the process signal and comparing them with a standard baseline previously formed. Up to 8 decision discriminants help to recognize spectral changes due to anomalies. In our application, to detect boiling as quickly as possible with sufficient sensitivity, Piety's algorithm was modified using overlapped Fast-Fourier-Transform-Processing and the averaging of the PSDs over a large sample of preceding instantaneous PSDs. This processing allows high sensitivity in detecting weak disturbances without reducing response time. The algorithm was tested with simulation-of-boiling experiments where nitrogen in a cooling channel of a mock-up of a fuel element was injected. Void fractions higher than 30 % in the channel can be detected. In the case of boiling, it is believed that this limit is lower because collapsing bubbles could give rise to stronger fluctuations. The algorithm was also tested with a boiling experiment where the reactor coolant flow was actually reduced. The results showed that the discriminant D5 of Piety's algorithm based on neutron noise obtained from the existing neutron chambers of the reactor control system could sensitively recognize boiling. The detection time amounts to 7-30 s depending on the strength of the disturbances. Other events, which arise during a normal reactor run like scrams, removal of isotope elements without scramming or control rod movements and which could lead to false alarms, can be distinguished from boiling. 49 refs., 104 figs., 5 tabs

  17. The progesterone-induced enhancement of object recognition memory consolidation involves activation of the extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin (mTOR) pathways in the dorsal hippocampus

    OpenAIRE

    Orr, Patrick T.; Rubin, Amanda J.; Fan, Lu; Kent, Brianne A.; Frick, Karyn M.

    2012-01-01

    Although much recent work has elucidated the biochemical mechanisms underlying the modulation of memory by 17β-estradiol, little is known about the signaling events through which progesterone (P) regulates memory. We recently demonstrated that immediate post-training infusion of P into the dorsal hippocampus enhances object recognition memory consolidation in young ovariectomized female mice (Orr et al., 2009). The goal of the present study was to identify the biochemical alterations that mig...

  18. Differential recognition of a dileucine-based sorting signal by AP-1 and AP-3 reveals a requirement for both BLOC-1 and AP-3 in delivery of OCA2 to melanosomes

    OpenAIRE

    Sitaram, Anand; Dennis, Megan K.; Chaudhuri, Rittik; De Jesus-Rojas, Wilfredo; Tenza, Danièle; Setty, Subba Rao Gangi; Wood, Christopher S.; Sviderskaya, Elena V.; Bennett, Dorothy C.; Raposo, Graça; Bonifacino, Juan S.; Marks, Michael S.

    2012-01-01

    Cell types that generate unique lysosome-related organelles (LROs), such as melanosomes in melanocytes, populate nascent LROs with cargoes that are diverted from endosomes. Cargo sorting toward melanosomes correlates with binding via cytoplasmically exposed sorting signals to either heterotetrameric adaptor AP-1 or AP-3. Some cargoes bind both adaptors, but the relative contribution of each adaptor to cargo recognition and their functional interactions with other effectors during transport to...

  19. The Casuarina NIN gene is transcriptionally activated throughout Frankia root infection as well as in response to bacterial diffusible signals.

    Science.gov (United States)

    Clavijo, Fernando; Diedhiou, Issa; Vaissayre, Virginie; Brottier, Laurent; Acolatse, Jennifer; Moukouanga, Daniel; Crabos, Amandine; Auguy, Florence; Franche, Claudine; Gherbi, Hassen; Champion, Antony; Hocher, Valerie; Barker, David; Bogusz, Didier; Tisa, Louis S; Svistoonoff, Sergio

    2015-11-01

    Root nodule symbioses (RNS) allow plants to acquire atmospheric nitrogen by establishing an intimate relationship with either rhizobia, the symbionts of legumes or Frankia in the case of actinorhizal plants. In legumes, NIN (Nodule INception) genes encode key transcription factors involved in nodulation. Here we report the characterization of CgNIN, a NIN gene from the actinorhizal tree Casuarina glauca using both phylogenetic analysis and transgenic plants expressing either ProCgNIN::reporter gene fusions or CgNIN RNAi constructs. We have found that CgNIN belongs to the same phylogenetic group as other symbiotic NIN genes and CgNIN is able to complement a legume nin mutant for the early steps of nodule development. CgNIN expression is correlated with infection by Frankia, including preinfection stages in developing root hairs, and is induced by culture supernatants. Knockdown mutants were impaired for nodulation and early root hair deformation responses were severely affected. However, no mycorrhizal phenotype was observed and no induction of CgNIN expression was detected in mycorrhizas. Our results indicate that elements specifically required for nodulation include NIN and possibly related gene networks derived from the nitrate signalling pathways. PMID:26096779

  20. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    Directory of Open Access Journals (Sweden)

    Wei Yang

    Full Text Available Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA-dependent pathway from an early stage upstream of NDR1 and EDS1.

  1. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    Science.gov (United States)

    Yang, Wei; Xu, Xiaonan; Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1.

  2. Rutin-Mediated Priming of Plant Resistance to Three Bacterial Pathogens Initiating the Early SA Signal Pathway.

    Science.gov (United States)

    Yang, Wei; Xu, Xiaonan; Li, Yang; Wang, Yingzi; Li, Ming; Wang, Yong; Ding, Xinhua; Chu, Zhaohui

    2016-01-01

    Flavonoids are ubiquitous in the plant kingdom and have many diverse functions, including UV protection, auxin transport inhibition, allelopathy, flower coloring and insect resistance. Here we show that rutin, a proud member of the flavonoid family, could be functional as an activator to improve plant disease resistances. Three plant species pretreated with 2 mM rutin were found to enhance resistance to Xanthomonas oryzae pv. oryzae, Ralstonia solanacearum, and Pseudomonas syringae pv. tomato strain DC3000 in rice, tobacco and Arabidopsis thaliana respectively. While they were normally propagated on the cultural medium supplemented with 2 mM rutin for those pathogenic bacteria. The enhanced resistance was associated with primed expression of several pathogenesis-related genes. We also demonstrated that the rutin-mediated priming resistance was attenuated in npr1, eds1, eds5, pad4-1, ndr1 mutants, and NahG transgenic Arabidopsis plant, while not in either snc1-11, ein2-5 or jar1 mutants. We concluded that the rutin-priming defense signal was modulated by the salicylic acid (SA)-dependent pathway from an early stage upstream of NDR1 and EDS1. PMID:26751786

  3. A structure activity-relationship study of the bacterial signal molecule HHQ reveals swarming motility inhibition in Bacillus atrophaeus.

    Science.gov (United States)

    Reen, F Jerry; Shanahan, Rachel; Cano, Rafael; O'Gara, Fergal; McGlacken, Gerard P

    2015-05-21

    The sharp rise in antimicrobial resistance has been matched by a decline in the identification and clinical introduction of new classes of drugs to target microbial infections. Thus new approaches are being sought to counter the pending threat of a post-antibiotic era. In that context, the use of non-growth limiting small molecules, that target virulence behaviour in pathogens, has emerged as a solution with real clinical potential. We have previously shown that two signal molecules (HHQ and PQS) from the nosocomial pathogen Pseudomonas aeruginosa have modulatory activity towards other microorganisms. This current study involves the synthesis and evaluation of analogues of HHQ towards swarming and biofilm virulence behaviour in Bacillus atrophaeus, a soil bacterium and co-inhibitor with P. aeruginosa. Compounds with altered C6-C8 positions on the anthranilate-derived ring of HHQ, display a surprising degree of biological specificity, with certain candidates displaying complete motility inhibition. In contrast, anti-biofilm activity of the parent molecule was completely lost upon alteration at any position indicating a remarkable degree of specificity and delineation of phenotype. PMID:25880413

  4. 一种单信道时频重叠信号调制识别方法%A Modulation Recognition Method for Time-Frequency Overlapped Signals in Single Channel

    Institute of Scientific and Technical Information of China (English)

    曾创展; 贾鑫; 刘淑茜

    2015-01-01

    To solve the problem of modulation recognition of two time-frequency overlapped signals in sin-gle channel,a method based on correlation characteristics is proposed. On the basis of studying the correla-tion characteristics of the selected digital communication signals,the spectrum peaks' amount,amplitudes, and location variance of signals' delay correlation and instantaneous correlation are extracted as the feature parameters to achieve modulation recognition of two time-frequency overlapped signals with the same carri-er frequency. Simulation results show that this method has good performance in the Gaussian noise, and when signal-to-noise ratio( SNR) is above -5 dB,the average correct recognition rate is beyond 95%.%针对单信道时频重叠信号调制方式的识别分类问题,提出了基于信号相关特性的调制识别方法. 在研究所选数字通信信号的相关特性的基础上,提取信号延迟相关和瞬时自相关谱峰的数量、幅度和位置方差作为特征参数,实现了同载频时频重叠双信号的调制识别. 仿真结果表明,在理想高斯白噪声背景下,该方法具有良好的识别性能,当信噪比大于-5 dB时,其正确识别率达到95%以上.

  5. Face Recognition

    OpenAIRE

    Haugen, Liv Merete; Olavsbråten, Inge

    2007-01-01

    Machine based face recognition has been a popular research area for several years, and has numerous applications. This technology has now reached a point where there already exists good algorithms for recognition for standardized still images - which have little variation in e.g. lighting, facial expression and pose. We are however in lack of good algorithms that are able to do recognition from live video. The low quality of most surveillance cameras, together with non-standardized imaging c...

  6. Research progress of bacterial quorum sensing—signal molecule%密度感应系统——细菌信号分子研究进展

    Institute of Scientific and Technical Information of China (English)

    周雯; 刘岚

    2012-01-01

    The process, termed quorum sensing system, regulates bacterial communication by the production of diffusible intercellular signal molecules. The molecules are produced during bacteria basal levels and accumulated during the growth process. Once the concentration level reached, the molecules can activate or repress the expressing of target genes, then these genes regulate the production of virulence factor, biofilm formation and so on. As the antibiotic resistance and multidrug resistance increase seriously, researchers hope to make the mechanism of quorum sensing much clearer, find some medicine which can inhibit quorum sensing system, and get a new choice for antibacterial treatment. But quorum sensing is much more complex than expected. Quorum sensing system of different bacteria or even different types of the same bacteria may be different. One bacterium may include more than one quorum sensing system. So this review summarizes several different common bacteria and gives focus on quorum sensing and the signal molecules.%细菌利用散在的细胞间信号分子产物介导细胞间通讯的这个整个过程被叫做密度感应系统.这些信号分子在细菌基础水平时产生,生长过程积累.当细菌密度达到阈值时信号分子则激活或抑制相关系列基因表达,从而影响毒力因子、生物膜等的产生.在抗生素耐药及多重耐药不断增加的背景下,研究者们希望明确此系统作用机制,了解可否寻找抑制它的物质并将其应用于临床协同抗生素治疗.但密度感应系统远比预想的复杂,不同细菌甚至是同种细菌不同分型可能有差异,同一细菌也可能有不同密度感应系统.故本文综述了目前研究较多的多种细菌的密度感应系统及其信号分子作用机制.

  7. Fingerprint recognition

    OpenAIRE

    Diefenderfer, Graig T.

    2006-01-01

    The use of biometrics is an evolving component in today's society. Fingerprint recognition continues to be one of the most widely used biometric systems. This thesis explores the various steps present in a fingerprint recognition system. The study develops a working algorithm to extract fingerprint minutiae from an input fingerprint image. This stage incorporates a variety of image pre-processing steps necessary for accurate minutiae extraction and includes two different methods of ridge thin...

  8. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa...... that appropriately target bacteria in their relevant habitat with the aim of mitigating their destructive impact on patients. In this review we describe molecular mechanisms involved in “bacterial gossip” (more scientifically referred to as quorum sensing (QS) and c-di-GMP signaling), virulence, biofilm formation...

  9. Research on passive human activity recognition using WiFi ambient signals%基于 WiFi 背景噪音的被动式人体行为识别研究

    Institute of Scientific and Technical Information of China (English)

    谷雨; 权良虎; 陈孟妮; 任福继

    2015-01-01

    Although traditional k‐nearest neighbor (K‐NN ) and Bagging can recognize effectively less human activities using WiFi ambient signal , recognition by either alone of the seven states , namely , empty ,walking ,sitting ,standing ,sleeping ,falling and running ,is not ideal . To improve recognition rates ,a new algorithm ,fusion algorithm ,was designed .It significantly outperforms K‐NN and Bagging in terms of recognition ratios in both single‐subject and multi‐subject experiments .%利用 WiFi 背景噪音,传统 K‐NN 和 Bagging 算法可有效识别较少人体行为,但对较多状态:无人、走、坐、站、睡、跌倒、跑,实验发现,单纯使用 K‐NN 和 Bagging 算法分类效果并不理想,故设计了一种新的融合算法。实验结果证实,融合算法相较于 K‐NN 和 Bagging 算法可以大幅提高识别准确率,将新算法应用于多人混合状态识别也取得较好的识别准确率。

  10. 基于智能算法的生理信号情感识别%Emotion Recognition of Physiological Signals Based on Intelligent Algorithm

    Institute of Scientific and Technical Information of China (English)

    熊勰; 刘光远; 温万惠

    2011-01-01

    针对基于生理信号的情感识别问题,采用具有模拟退火机制的遗传算法、最大最小蚁群算法和粒子群算法来进行特征选择,用Fisher分类器对高兴、惊奇、厌恶、悲伤、愤怒和恐惧6种情感进行分类,获得了较高的识别率,并找出了对情感识别系统模型的构建具有较好性能的特征组合,建立了对6类情感具有预测能力的识别系统.%For the problem of emotion recognition,genetic algorithm based on simulated-annealing method,max-min ant colony algorithm and particle swarm algorithm were used for feature selection, and combined with Fisher linear classifier to recognize six emotions:joy, surprise, disgust, grief, anger and fear, it has obtained higher recognition rate. Effective feature subset which can identify the emotion recognition system model with better performance was found,and the reco gnition system was established with forecasting ability of six emotions.

  11. 基于HMM和ANN的语音情感识别研究%Research on emotion recognition of speech signal based on HMM and ANN

    Institute of Scientific and Technical Information of China (English)

    胡洋; 蒲南江; 吴黎慧; 高磊

    2011-01-01

    Speech emotion recognition is not only an important part of speech recognition but also the basic theory of harmonious human-computer interaction.As a single classifier in the limitations of speech emotion recognition.In this paper,we put forward a method:the Combination of Hidden Markov Model (HMM) and Artificial Neural Network (ANN),for the six emotion of happy,surprise,anger,sad,fear and clam,we design six HMM model for every emotion,through this method,we have the best matching sequence of each emotion.Then,the posterior ANN classifier is used to classify the test samples,through the integration of two classifiers to improve speech emotion recognition rate.Based on the emotion speech database established by recording induced,the experimental results indicate that there is great elevation in the recognition rate.%语音情感识别是语音识别中的重要分支,是和谐人机交互的基础理论。由于单一分类器在语音情感识别中的局限性,本文提出了隐马尔科夫模型(HMM)和人工神经网络(ANN)相结合的方法,对高兴、惊奇、愤怒、悲伤、恐惧、平静六种情感分别设计一个HMM模型,得到每种情感的最佳匹配序列,然后利用ANN作为后验分类器对测试样本进行分类,通过两种分类器融合提高语音情感识别率。在通过诱导录音法建立的情感语音库的基础上进行了实验验证,实验结果表明识别率有较大的提高。

  12. Customer recognition and competition

    OpenAIRE

    Shy, Oz; Stenbacka , Rune

    2011-01-01

    We introduce three types of consumer recognition: identity recognition, asymmetric preference recognition, and symmetric preference recognition. We characterize price equilibria and compare profits, consumer surplus, and total welfare. Asymmetric preference recognition enhances profits compared with identity recognition, but firms have no incentive to exchange information regarding customer-specific preferences (symmetric preference recognition). Consumers would benefit from a policy panning ...

  13. Recognition of Frequency Modulation Signal Using Parameter Invariant Filter%频率调制信号的恒参滤波识别方法

    Institute of Scientific and Technical Information of China (English)

    姚亚峰; 陈建文; 黄载禄

    2005-01-01

    To classify the frequency modulation signal, this paper employs a parameter invariant filter, which can transfer the frequency modulated information to variety of its envelope, and then extracts the histogram feature to classify the modulation type. This method can efficiently classify the type of a signal such as frequency modulation (FM), binary frequency shift keyiing (BFSK), quadrature frequency shift keying (QFSK), 8-ary frequency shift keying (8FSK), etc. It can easily be realized and is especially suitable to applications in software radio.

  14. Leaky gut and the liver: A role for bacterial translocation in nonalcoholic steatohepatitis

    Institute of Scientific and Technical Information of China (English)

    Yaron Ilan

    2012-01-01

    Gut flora and bacterial translocation (BT) play important roles in the pathogenesis of chronic liver disease,including cirrhosis and its complications.Intestinal bacterial overgrowth and increased bacterial translocation of gut flora from the intestinal lumen predispose patients to bacterial infections,major complications and also play a role in the pathogenesis of chronic liver disorders.Levels of bacterial lipopolysaccharide,a component of gram-negative bacteria,are increased in the portal and/or systemic circulation in several types of chronic liver disease.Impaired gut epithelial integrity due to alterations in tight junction proteins may be the pathological mechanism underlying bacterial translocation.Preclinical and clinical studies over the last decade have suggested a role for BT in the pathogenesis of nonalcoholic steatohepatitis (NASH).Bacterial overgrowth,immune dysfunction,alteration of the luminal factors,and altered intestinal permeability are all involved in the pathogenesis of NASH and its complications.A better understanding of the cell-specific recognition and intracellular signaling events involved in sensing gut-derived microbes will help in the development of means to achieve an optimal balance in the gut-liver axis and ameliorate liver diseases.These may suggest new targets for potential therapeutic interventions for the treatment of NASH.Here,we review some of the mechanisms connecting BT and NASH and potential therapeutic developments.

  15. Bacterial surface adaptation

    Science.gov (United States)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  16. 基于功率谱和共振峰的母羊发声信号识别%Vocal signal recognition of ewes based on power spectrum and formant analysis method

    Institute of Scientific and Technical Information of China (English)

    宣传忠; 武佩; 马彦华; 张丽娜; 韩丁; 刘艳秋

    2015-01-01

    Inner Mongolia and its surrounding areas in the west are developing an intensive and large-scale sheep farming operation, in which sheep are bred with planting forage and are placed in captive facilities. However, the breeding pattern of such operation needs a high level of animal welfare management. Considering that sheep makes different vocalization in different emergent situations, ewes’ vocalization can be used as an important evidence for ewes’ health monitoring and breeding welfare evaluation. In this paper, taking Small Tail Han sheep as an example, ewes’ vocalization signals were evenly collected from 80 adult ewes under 3 stress behaviors including searching lamb, hunger, and scare via a wireless audio surveillance device. Then, these continuous vocal signals of ewes were split into 1 200 single call signals using Audacity Acoustic Edit software. The band-pass filter and wavelet denoising methods were applied to preprocess those single sound signals. Six hundred of those sound signals, which were comprised of three different stress behaviors by random selected 200 signals, were analyzed to extract ewes’ acoustic characteristic parameters using auto-regressive (AR) power spectrum estimation and formant extraction methods, respectively. Therefore, six representative frequency characteristic parameters from AR power spectrum estimation method were extracted: the power spectrum density mean, the geometric mean, the median value, the trimmed mean, the mean absolute deviation, and inter quartile deviation, and characteristics parameters from formant analysis method were the first, second and third formant frequency. Moreover, typical time-domain characteristic parameters such as signal maximum value, duration value and interval value were taken as well. Then, these characteristic parameters were used to train the back propagation (BP) neural network model of ewes’ vocalization recognition, and the rest of 600 vocal signals were used to test the effects

  17. Pseudomonas evades immune recognition of flagellin in both mammals and plants.

    Directory of Open Access Journals (Sweden)

    Bart W Bardoel

    2011-08-01

    Full Text Available The building blocks of bacterial flagella, flagellin monomers, are potent stimulators of host innate immune systems. Recognition of flagellin monomers occurs by flagellin-specific pattern-recognition receptors, such as Toll-like receptor 5 (TLR5 in mammals and flagellin-sensitive 2 (FLS2 in plants. Activation of these immune systems via flagellin leads eventually to elimination of the bacterium from the host. In order to prevent immune activation and thus favor survival in the host, bacteria secrete many proteins that hamper such recognition. In our search for Toll like receptor (TLR antagonists, we screened bacterial supernatants and identified alkaline protease (AprA of Pseudomonas aeruginosa as a TLR5 signaling inhibitor as evidenced by a marked reduction in IL-8 production and NF-κB activation. AprA effectively degrades the TLR5 ligand monomeric flagellin, while polymeric flagellin (involved in bacterial motility and TLR5 itself resist degradation. The natural occurring alkaline protease inhibitor AprI of P. aeruginosa blocked flagellin degradation by AprA. P. aeruginosa aprA mutants induced an over 100-fold enhanced activation of TLR5 signaling, because they fail to degrade excess monomeric flagellin in their environment. Interestingly, AprA also prevents flagellin-mediated immune responses (such as growth inhibition and callose deposition in Arabidopsis thaliana plants. This was due to decreased activation of the receptor FLS2 and clearly demonstrated by delayed stomatal closure with live bacteria in plants. Thus, by degrading the ligand for TLR5 and FLS2, P. aeruginosa escapes recognition by the innate immune systems of both mammals and plants.

  18. A case of myopathy with anti-signal recognition particle antibodies and literature review%抗信号识别颗粒抗体阳性的肌病一例并文献复习

    Institute of Scientific and Technical Information of China (English)

    邸丽; 笪宇威; 王敏; 卢岩; 张新卿; 贾建平

    2012-01-01

    Objective To analyze the clinical and pathological features of myopathy with anti-signal recognition particle antibodies. Methods The clinical data of one case of myopathy with anti-signal recognition particle antibodies were analyzed retrospectively and related literatures were reviewed. Results The clinical features of the patient were proximal muscle weakness, dysphagia and highly elevated levels of serum creatine kinase. Frozen sections of muscle biopsy samples showed numerous necrotic and regenerating fibers; no obvious inflammatory infiltrates in perimysium and endomysium. Only treatment with glucocorticoid could not be well, need to combined with immunosuppressive agent. Conclusions Myopathy with anti-signal recognition particle antibodies is one of immune-mediated myopathies, which prominent manifestations are severe symmetric proximal muscle weakness, dysphagia and highly elevated levels of serum creatine kinase. The main pathological changes are prominent necrotic and regenerating fibers, no obvious inflammatory infiltrates. This disease is responsive to corticosteroids and immunosuppression.%目的 分析抗信号识别颗粒抗体阳性的肌病的临床与病理特点.方法 回顾性分析1例抗信号识别颗粒抗体阳性的肌病患者的临床资料,并对此病相关文献进行复习.结果 患者主要表现为近端肢体无力,早期出现吞咽困难;血清肌酶显著升高;病理检查示肌纤维内可见坏死和较多再生肌纤维,肌束衣肌内衣未见明显炎细胞浸润;单用糖皮质激素效果欠佳,需合用免疫抑制剂.结论 抗信号识别颗粒抗体阳性的肌病是一种以严重的对称性进行性近端肌无力、吞咽困难及血清肌酶显著升高为主要临床表现的免疫介导坏死性肌病,病理改变以肌纤维坏死和再生为主,无或较少炎症细胞浸润.糖皮质激素联合免疫抑制剂治疗可获得较好疗效.

  19. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  20. The effect of using integrated signal processing hearing aids on the speech recognition abilities of hearing impaired Arabic-speaking children

    Directory of Open Access Journals (Sweden)

    Somaia Tawfik

    2014-11-01

    Results and conclusions: Significant improvement in aided sound field threshold levels and speech recognition in noise tests was recorded using ISP HAs over time. As regards consonant manner, glides and stop consonants showed the highest improvement. Though voiced and voiceless consonants were equally transmitted through digital HAs, voiced consonants were easier to perceive using ISP HAs. Middle and back consonants were easier to perceive compared to front consonants using both HAs. Application of WILSI self assessment questionnaire revealed that parents reported better performance in different listening situations. In conclusion, results of the present study support the use of ISP HAs in children with moderate to severe hearing loss due to the significant improvement recorded in both subjective and objective measures.

  1. Do calcium-mediated cellular signalling pathways, prostaglandin E2 (PGE2), estrogen or progesterone receptor antagonists, or bacterial endotoxins affect bovine placental function in vitro?

    Science.gov (United States)

    Weems, Y S; Randel, R D; Carstens, G E; Welsh, T H; Weems, C W

    2004-04-01

    .05). Concentrations of PGE2 in media at 4 and 8 h were lower (P or = 0.05). PGF2alpha was increased (P < or = 0.05) by RU-486 at 8h and no other treatment affected PGF2alpha at 4 or 8 h (P < or = 0.05). In conclusion, modulators of cellular calcium signalling pathways given alone do not affect bovine placental progesterone secretion at the days studied and progesterone receptor-mediated events appear to suppress placental progesterone, PGF2alpha, and PGE2 secretion in cattle. In addition, PGE2 does not appear to regulate bovine placental progesterone secretion when the corpus luteum is functional and bacterial endotoxin does not appear to affect bovine placental secretion of PGF2alpha or PGE2. PMID:15287156

  2. The glove-like structure of the conserved membrane protein TatC provides insight into signal sequence recognition in twin-arginine translocation.

    Science.gov (United States)

    Ramasamy, Sureshkumar; Abrol, Ravinder; Suloway, Christian J M; Clemons, William M

    2013-05-01

    In bacteria, two signal-sequence-dependent secretion pathways translocate proteins across the cytoplasmic membrane. Although the mechanism of the ubiquitous general secretory pathway is becoming well understood, that of the twin-arginine translocation pathway, responsible for translocation of folded proteins across the bilayer, is more mysterious. TatC, the largest and most conserved of three integral membrane components, provides the initial binding site of the signal sequence prior to pore assembly. Here, we present two crystal structures of TatC from the thermophilic bacteria Aquifex aeolicus at 4.0 Å and 6.8 Å resolution. The membrane architecture of TatC includes a glove-shaped structure with a lipid-exposed pocket predicted by molecular dynamics to distort the membrane. Correlating the biochemical literature to these results suggests that the signal sequence binds in this pocket, leading to structural changes that facilitate higher order assemblies. PMID:23583035

  3. 基于瞬态压力信号探测识别的无线分布式测试系统%Wireless distributed test system based on transient pressure signal detection and recognition

    Institute of Scientific and Technical Information of China (English)

    贾振华; 王文廉

    2016-01-01

    During the test on transient pressure signal in explosion field,false trigger caused by field interference can lead to test failure.To improve the stability of test system,a signal detection and recognition technology is proposed for transient pressure test system.In the process of signal acquisition,firstly,electrical levels are monitored in real time to find effective abrupt chan-ges and mark them;then the effective data segments are detecdted totected;thus the effective signals can be acquired in turn fi-nally.The experimental results show that the shock wave signal can be collected effectively and the reliability of the test system can be improved after removal of interferences.%在爆炸场的瞬态压力测试过程中,现场干扰容易引起误触发导致测试失败。为了提高测试系统的稳定性,本文提出了一种信号探测识别技术用于压力测试系统。在信号循环采集过程中,通过实时检测电平值,标记有效突变,对有效数据段进行特征检测,从而识别出有效信号进行顺序采集。实验证明,该系统实现了冲击波信号有效采集、减少了干扰以提高测试可靠性。

  4. Facial Recognition

    Directory of Open Access Journals (Sweden)

    Mihalache Sergiu

    2014-05-01

    Full Text Available During their lifetime, people learn to recognize thousands of faces that they interact with. Face perception refers to an individual's understanding and interpretation of the face, particularly the human face, especially in relation to the associated information processing in the brain. The proportions and expressions of the human face are important to identify origin, emotional tendencies, health qualities, and some social information. From birth, faces are important in the individual's social interaction. Face perceptions are very complex as the recognition of facial expressions involves extensive and diverse areas in the brain. Our main goal is to put emphasis on presenting human faces specialized studies, and also to highlight the importance of attractiviness in their retention. We will see that there are many factors that influence face recognition.

  5. Examining the critical roles of human CB2 receptor residues Valine 3.32 (113) and Leucine 5.41 (192) in ligand recognition and downstream signaling activities.

    Science.gov (United States)

    Alqarni, Mohammed; Myint, Kyaw Zeyar; Tong, Qin; Yang, Peng; Bartlow, Patrick; Wang, Lirong; Feng, Rentian; Xie, Xiang-Qun

    2014-09-26

    We performed molecular modeling and docking to predict a putative binding pocket and associated ligand-receptor interactions for human cannabinoid receptor 2 (CB2). Our data showed that two hydrophobic residues came in close contact with three structurally distinct CB2 ligands: CP-55,940, SR144528 and XIE95-26. Site-directed mutagenesis experiments and subsequent functional assays implicated the roles of Valine residue at position 3.32 (V113) and Leucine residue at position 5.41 (L192) in the ligand binding function and downstream signaling activities of the CB2 receptor. Four different point mutations were introduced to the wild type CB2 receptor: V113E, V113L, L192S and L192A. Our results showed that mutation of Val113 with a Glutamic acid and Leu192 with a Serine led to the complete loss of CB2 ligand binding as well as downstream signaling activities. Substitution of these residues with those that have similar hydrophobic side chains such as Leucine (V113L) and Alanine (L192A), however, allowed CB2 to retain both its ligand binding and signaling functions. Our modeling results validated by competition binding and site-directed mutagenesis experiments suggest that residues V113 and L192 play important roles in ligand binding and downstream signaling transduction of the CB2 receptor.

  6. Dopamine D1 Receptors Regulate Protein Synthesis-Dependent Long-Term Recognition Memory via Extracellular Signal-Regulated Kinase 1/2 in the Prefrontal Cortex

    Science.gov (United States)

    Nagai, Taku; Takuma, Kazuhiro; Kamei, Hiroyuki; Ito, Yukio; Nakamichi, Noritaka; Ibi, Daisuke; Nakanishi, Yutaka; Murai, Masaaki; Mizoguchi, Hiroyuki; Nabeshima, Toshitaka; Yamada, Kiyofumi

    2007-01-01

    Several lines of evidence suggest that extracellular signal-regulated kinase1/2 (ERK1/2) and dopaminergic system is involved in learning and memory. However, it remains to be determined if the dopaminergic system and ERK1/2 pathway contribute to cognitive function in the prefrontal cortex (PFC). The amount of phosphorylated ERK1/2 was increased in…

  7. The well-tuned blues: the role of structural colours as optical signals in the species recognition of a local butterfly fauna (Lepidoptera: Lycaenidae: Polyommatinae).

    Science.gov (United States)

    Bálint, Zsolt; Kertész, Krisztián; Piszter, Gábor; Vértesy, Zofia; Biró, László P

    2012-08-01

    The photonic nanoarchitectures responsible for the blue colour of the males of nine polyommatine butterfly species living in the same site were investigated structurally by electron microscopy and spectrally by reflectance spectroscopy. Optical characterization was carried out on 110 exemplars. The structural data extracted by dedicated software and the spectral data extracted by standard software were inputted into an artificial neural network software to test the specificity of the structural and optical characteristics. It was found that both the structural and the spectral data allow species identification with an accuracy better than 90 per cent. The reflectance data were further analysed using a colour representation diagram built in a manner analogous to that of the human Commission Internationale de l'Eclairage diagram, but the additional blue visual pigment of lycaenid butterflies was taken into account. It was found that this butterfly-specific colour representation diagram yielded a much clearer distinction of the position of the investigated species compared with previous calculations using the human colour space. The specific colours of the investigated species were correlated with the 285 flight-period data points extracted from museum collections. The species with somewhat similar colours fly in distinct periods of the year such that the blue colours are well tuned for safe mate/competitor recognition. This allows for the creation of an effective pre-zygotic isolation mechanism for closely related synchronic and syntopic species.

  8. Complex Role of the Mitochondrial Targeting Signal in the Function of Steroidogenic Acute Regulatory Protein Revealed by Bacterial Artificial Chromosome Transgenesis in Vivo

    OpenAIRE

    Sasaki, Goro; Ishii, Tomohiro; Jeyasuria, Pancharatnam; Jo, Youngah; Bahat, Assaf; Orly, Joseph; Hasegawa, Tomonobu; Parker, Keith L.

    2008-01-01

    The steroidogenic acute regulatory protein (StAR) stimulates the regulated production of steroid hormones in the adrenal cortex and gonads by facilitating the delivery of cholesterol to the inner mitochondrial membrane. To explore key aspects of StAR function within bona fide steroidogenic cells, we used a transgenic mouse model to explore the function of StAR proteins in vivo. We first validated this transgenic bacterial artificial chromosome reconstitution system by targeting enhanced green...

  9. Are Bacterial Volatile Compounds Poisonous Odors to a Fungal Pathogen Botrytis cinerea, Alarm Signals to Arabidopsis Seedlings for Eliciting Induced Resistance, or Both?

    OpenAIRE

    Sharifi, Rouhallah; Ryu, Choong-Min

    2016-01-01

    Biological control (biocontrol) agents act on plants via numerous mechanisms, and can be used to protect plants from pathogens. Biocontrol agents can act directly as pathogen antagonists or competitors or indirectly to promote plant induced systemic resistance (ISR). Whether a biocontrol agent acts directly or indirectly depends on the specific strain and the pathosystem type. We reported previously that bacterial volatile organic compounds (VOCs) are determinants for eliciting plant ISR. Eme...

  10. Involvement of bacterial TonB-dependent signaling in the generation of an oligogalacturonide damage-associated molecular pattern from plant cell walls exposed to Xanthomonas campestris pv. campestris pectate lyases

    Directory of Open Access Journals (Sweden)

    Vorhölter Frank-Jörg

    2012-10-01

    Full Text Available Abstract Background Efficient perception of attacking pathogens is essential for plants. Plant defense is evoked by molecules termed elicitors. Endogenous elicitors or damage-associated molecular patterns (DAMPs originate from plant materials upon injury or pathogen activity. While there are comparably well-characterized examples for DAMPs, often oligogalacturonides (OGAs, generated by the activity of fungal pathogens, endogenous elicitors evoked by bacterial pathogens have been rarely described. In particular, the signal perception and transduction processes involved in DAMP generation are poorly characterized. Results A mutant strain of the phytopathogenic bacterium Xanthomonas campestris pv. campestris deficient in exbD2, which encodes a component of its unusual elaborate TonB system, had impaired pectate lyase activity and caused no visible symptoms for defense on the non-host plant pepper (Capsicum annuum. A co-incubation of X. campestris pv. campestris with isolated cell wall material from C. annuum led to the release of compounds which induced an oxidative burst in cell suspension cultures of the non-host plant. Lipopolysaccharides and proteins were ruled out as elicitors by polymyxin B and heat treatment, respectively. After hydrolysis with trifluoroacetic acid and subsequent HPAE chromatography, the elicitor preparation contained galacturonic acid, the monosaccharide constituent of pectate. OGAs were isolated from this crude elicitor preparation by HPAEC and tested for their biological activity. While small OGAs were unable to induce an oxidative burst, the elicitor activity in cell suspension cultures of the non-host plants tobacco and pepper increased with the degree of polymerization (DP. Maximal elicitor activity was observed for DPs exceeding 8. In contrast to the X. campestris pv. campestris wild type B100, the exbD2 mutant was unable to generate elicitor activity from plant cell wall material or from pectin. Conclusions To our

  11. Optical Pattern Recognition With Self-Amplification

    Science.gov (United States)

    Liu, Hua-Kuang

    1994-01-01

    In optical pattern recognition system with self-amplification, no reference beam used in addressing mode. Polarization of laser beam and orientation of photorefractive crystal chosen to maximize photorefractive effect. Intensity of recognition signal is orders of magnitude greater than other optical correlators. Apparatus regarded as real-time or quasi-real-time optical pattern recognizer with memory and reprogrammability.

  12. Stable and Critical Gesture Recognition in Children and Pregnant Women by SVM Classification with FFT Features of Signals from Wearable Attires

    Directory of Open Access Journals (Sweden)

    A. Sheryl Oliver

    2014-06-01

    Full Text Available The aim is to identify stable and critical recognition in children and pregnant women by wearable interface based monitoring system. The objective of this research proposal is to identify safe and danger zone prediction in toddler and normal and contra pain in pregnant women. The technology supporting this analysis of gesture has advanced dramatically. Past decades of remote health care monitoring have provided us with significant knowledge about the accuracy of tests performed. Mainly motivated by increasing healthcare costs and propelled by recent technological advances in miniature bio sensing devices, smart textiles, microelectronics and wireless communications, the continuous advance of wearable sensor-based systems will potentially transform the future of healthcare by enabling proactive personal health management and ubiquitous monitoring of a toddler and pregnant women health condition.The remote healthcare monitoring on a care taking base involves many implicit observations between the subjects and the care takers. Any ignorance and negligence leads to unpleasant situations thereafter. A simple wearable attire system can precisely interpret the implicit communication of the state of the subject and pass it to the care takers or to an automated aid device. Casual and conventional movements of subjects during play and living condition can be used for the above purpose. The methodology suggests a novel way of identifying safe and unsafe conditions of playing for the children as well as normal and critical situations of pregnant women where a medical assistance is desperately required. The experimental results show a well-distinguished realization of different body movement activities using a wearable attire array medium and the interpretation results always show significant and identifiable thresholds.

  13. Biomimetic/Optical Sensors for Detecting Bacterial Species

    Science.gov (United States)

    Homer, Margie; Ksendzov, Alexander; Yen, Shiao-Pin; Ryan, Margaret; Lazazzera, Beth

    2006-01-01

    Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum-signaling compounds are acyl-homoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum. A sensor according to the proposal would include a specially formulated biomimetic film, made of a molecularly imprinted polymer (MIP), that would respond optically to the signaling compound of interest. The MIP film would be integrated directly onto an opticalwaveguide- based ring resonator for optical readout. Optically, the sensor would resemble the one described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. MIPs have been used before as molecular- recognition compounds, though not in the manner of the present proposal. Molecular imprinting is an approach to making molecularly selective cavities in a polymer matrix. These cavities function much as enzyme receptor sites: the chemical functionality and shape of a cavity in the polymer matrix cause the cavity to bind to specific molecules. An MIP matrix is made by polymerizing monomers in the presence of the compound of interest (template molecule). The polymer forms around the template. After the polymer solidifies, the template molecules are removed from the polymer matrix by decomplexing them from their binding sites and then dissolving them, leaving cavities that are matched to the template molecules in size, shape, and chemical functionality. The cavities thus become molecular-recognition sites

  14. Feature Analysis and Recognition of Induced Uranium Components Fission Signal Based on BP Neural Network%基于BP神经网络的诱发铀部件裂变信号特征分析及识别

    Institute of Scientific and Technical Information of China (English)

    谢军华; 刘知贵; 任立学; 张活力

    2012-01-01

    The paper presents feature parameter analysis and processing in fission time-dependent signal of induced uranium components based on BP-Neural Networks through the analysis of the measuring princi- ple and signal characteristics of induced uranium components fission signal. The auto correlation functions and cross correlation functions are calculated by using unbiased estimate, and then the feature parameters of fission signal in different status are extracted by using feature abstraction method, comparative method and derivative method, and then applied to training and prediction by means of BP-neural networks based on pattern recognition. Theoretical analysis and the results show that, it is effective to obtain feature pa- rameters of induced uranium component fission signal via comparative method and derivative method. Using BP neural network to tiveness and reasonability of recognize patter of fission signal, we got good results that verified the effec the method.%在对诱发铀部件裂变信号的测量原理及特点分析的基础上,开展了基于BP神经网络的诱发铀部件裂变时间关联信号特征参量分析处理的研究工作。采用无偏估计方法,计算信号的自相关函数和互相关函数,再利用比较法和导数法两种特征量提取方法,提取出不同状态下裂变信号的特征参量,借助于BP神经网络模式识别应用原理进行训练和预测。理论分析和研究结果表明:基于比较法和导数法获得的特征参量能较好地反映诱发铀部件裂变信号的特征;用BP神经网络对裂变信号进行模式识别,取得了较高的正确率,验证了此方法的有效性和合理性。

  15. Recognition intent and visual word recognition.

    Science.gov (United States)

    Wang, Man-Ying; Ching, Chi-Le

    2009-03-01

    This study adopted a change detection task to investigate whether and how recognition intent affects the construction of orthographic representation in visual word recognition. Chinese readers (Experiment 1-1) and nonreaders (Experiment 1-2) detected color changes in radical components of Chinese characters. Explicit recognition demand was imposed in Experiment 2 by an additional recognition task. When the recognition was implicit, a bias favoring the radical location informative of character identity was found in Chinese readers (Experiment 1-1), but not nonreaders (Experiment 1-2). With explicit recognition demands, the effect of radical location interacted with radical function and word frequency (Experiment 2). An estimate of identification performance under implicit recognition was derived in Experiment 3. These findings reflect the joint influence of recognition intent and orthographic regularity in shaping readers' orthographic representation. The implication for the role of visual attention in word recognition was also discussed. PMID:19036609

  16. Recognition of Distracted Driving Based on Driver Operation Signals and Vehicle Trajectory%基于驾驶员操纵及车辆运动轨迹信息的驾驶分心辨识方法

    Institute of Scientific and Technical Information of China (English)

    王加; 陈慧

    2013-01-01

    提出了一种驾驶分心辨识方法,该方法采用的信号可从配备了车道偏离报警系统的车辆上获得。在驾驶模拟器上,驾驶员通过在驾驶过程中执行第二任务模拟分心驾驶,从而获得专注与分心两种驾驶状态下的数据。采用车辆偏航角以及转向盘转速的标准差作为辨识特征量,基于高斯混合隐马尔可夫模型,建立了专注与分心的驾驶员状态模型。对模型的离线验证表明,该方法对驾驶分心辨识具有较高的准确率。%The paper presents a driving distraction recognition method, which uses readily-available signals from a vehicle equipped with lane departure warning system. By performing the secondary task to simulate distracted driving, data of concentrated driving and distracted driving is obtained on the driving simulator. The standard deviation of vehicle yaw angle and steering wheel velocity are used as recognition characteristic value. Concentrated driving state model and distracted driving state model are established based on Gaussian Mixture-Hidden Markov Model (GM-HMM). The model offline proves that this method can accurately recognize distracted driving.

  17. Bipartite recognition of DNA by TCF/Pangolin is remarkably flexible and contributes to transcriptional responsiveness and tissue specificity of wingless signaling.

    Directory of Open Access Journals (Sweden)

    Hilary C Archbold

    2014-09-01

    Full Text Available The T-cell factor (TCF family of transcription factors are major mediators of Wnt/β-catenin signaling in metazoans. All TCFs contain a High Mobility Group (HMG domain that possesses specific DNA binding activity. In addition, many TCFs contain a second DNA binding domain, the C-clamp, which binds to DNA motifs referred to as Helper sites. While HMG and Helper sites are both important for the activation of several Wnt dependent cis-regulatory modules (W-CRMs, the rules of what constitutes a functional HMG-Helper site pair are unknown. In this report, we employed a combination of in vitro binding, reporter gene analysis and bioinformatics to address this question, using the Drosophila family member TCF/Pangolin (TCF/Pan as a model. We found that while there were constraints for the orientation and spacing of HMG-Helper pairs, the presence of a Helper site near a HMG site in any orientation increased binding and transcriptional response, with some orientations displaying tissue-specific patterns. We found that altering an HMG-Helper site pair from a sub-optimal to optimal orientation/spacing dramatically increased the responsiveness of a W-CRM in several fly tissues. In addition, we used the knowledge gained to bioinformatically identify two novel W-CRMs, one that was activated by Wnt/β-catenin signaling in the prothoracic gland, a tissue not previously connected to this pathway. In sum, this work extends the importance of Helper sites in fly W-CRMs and suggests that the type of HMG-Helper pair is a major factor in setting the threshold for Wnt activation and tissue-responsiveness.

  18. 一种基于加速度信息的上肢动作识别研究方法%A Research Method of Human Upper Limb Motion Recognition Based on Acceleration Signal

    Institute of Scientific and Technical Information of China (English)

    洪俊; 赵子恺

    2014-01-01

    A new method of binary decision analysis based GM threshold was proposed,applying to the research on recognition of human upper limb motion.The human motion acceleration acquisition system was designed,based on selection of the MEMS triaxial acceleration sensor ADXL345 .Through defined types of actions to do experiments,after obtained the three dimensional (3-D)acceler-ation signal of the body to perform upper limb actions,first the wavelet threshold denoising was preprocessed,extracting the Geometric Mean (GM)of upper limb actions as feature to select threshold.The experimental results show that,combined with wavelet analysis theory,this method based on GM threshold achieves the recognition of the type of action of the human upper limb,and validates the simplicity and efficiency of the system design and the theoretical algorithms,which has some reference value to research on human mo-tion recognition based on acceleration sensor.%提出一种基于GM阈值的二叉判决分析法,应用于人体上肢动作的分类识别研究。选用ME MS三轴加速度传感器ADXL345,设计一套人体动作的加速度采集系统。自定义上肢动作进行实验,采集人体执行上肢动作时的三维加速度信号后,进行小波阈值去噪的预处理过程,提取上肢动作的几何均值GM (Geometric Mean)作为特征值进行阈值的选取。实验结果表明:结合小波分析理论方法,基于GM阈值的方法实现了人体上肢动作的分类识别,并验证了系统设计及理论算法的简便性、高效性,对基于加速度传感器的动作识别研究具有一定的参考价值。

  19. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  20. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  1. DETECCIÓN Y RECONOCIMIENTO DE SEÑALES DE TRÁNSITO UTILIZANDO MATCHING DE CHAMFER DETECTION AND RECOGNITION OF TRAFFIC SIGNALS USING MATCHING OF CHAMFER

    Directory of Open Access Journals (Sweden)

    Cristián Arriagada García

    2007-08-01

    available details at first sight etc, in our case a prototype is presented which allows the opportunity to help a car driver to pay attention to the traffic signs on the road, attempting to assist the driver, and at the same time to avoid traffic infractions and accidents. The prototype developed with computer vision techniques, allows the detection and recognition of signposts that are on the road and to inform its nature to the driver through an audible sign or a visual projection. The research was mainly centered on the phases of initial detection; with the objective of taking into account a quick heuristic, taking advantage of the segmentation by color, with their characteristics of invariability of system HSV (Brightness, Saturation, Value [10], and/or initial detection by borders, making use of the improved algorithm of Chamfer [1], finally to detect and recognize the symbols of the sign, using transformation of distance techniques and hierarchical matching of Chamfer[1], conditioned to this kind of application. The prototype in the phase of proof was implemented in Matlab, with the initial purpose of proving the effectiveness of the methods that were used. Once they are proved an OpenCV was used to verify its functioning in real time.

  2. The inflammasomes: Molecular effectors of host resistance against bacterial, viral, parasitic and fungal infections

    Directory of Open Access Journals (Sweden)

    Alexander eSkeldon

    2011-02-01

    Full Text Available The inflammasomes are large multi-protein complexes scaffolded by cytosolic pattern recognition receptors (PRRs that form an important part of the innate immune system. They are activated following the recognition of microbial-associated molecular patterns (MAMPs or host-derived danger signals (danger-associated molecular patterns or DAMPs by PRRs. This recognition results in the recruitment and activation of the pro-inflammatory protease caspase-1, which cleaves its preferred substrates pro-interleukin-1β (IL-1β and pro-IL-18 into their mature biologically active cytokine forms. Through processing of a number of other cellular substrates, caspase-1 is also required for the release of alarmins and the induction and execution of an inflammatory form of cell death termed pyroptosis. A growing spectrum of inflammasomes have been identified in the host defence against a variety of pathogens. Reciprocally, pathogens have evolved effector strategies to antagonize the inflammasome pathway. In this review we discuss recent developments in the understanding of inflammasome-mediated recognition of bacterial, viral, parasitic and fungal infections and the beneficial or detrimental effects of inflammasome signalling in host resistance.

  3. Recognition of extracellular bacteria by NLRs and its role in the development of adaptive immunity

    Directory of Open Access Journals (Sweden)

    Jonathan eFerrand

    2013-10-01

    Full Text Available Innate immune recognition of bacteria is the first requirement for mounting an effective immune response able to control infection. Over the previous decade, the general paradigm was that extracellular bacteria were only sensed by cell surface-expressed Toll-like receptors (TLRs, whereas cytoplasmic sensors, including members of the Nod-like receptor (NLR family, were specific to pathogens capable of breaching the host cell membrane. It has become apparent, however, that intracellular innate immune molecules, such as the NLRs, play key roles in the sensing of not only intracellular, but also extracellular bacterial pathogens or their components. In this review, we will discuss the various mechanisms used by bacteria to activate NLR signaling in host cells. These mechanisms include bacterial secretion systems, pore-forming toxins and outer membrane vesicles. We will then focus on the influence of NLR activation on the development of adaptive immune responses in different cell types.

  4. Online recognition of the multiphase flow regime

    Institute of Scientific and Technical Information of China (English)

    BAI BoFeng; ZHANG ShaoJun; ZHAO Liang; ZHANG XiMin; GUO LieJin

    2008-01-01

    The key reasons that the present method cannot be used to solve the industrial multi-phase flow pattern recognition are clarified firstly. The prerequisite to realize the online recognition is proposed and recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance.

  5. Online recognition of the multiphase flow regime

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The key reasons that the present method cannot be used to solve the industrial multi- phase flow pattern recognition are clarified firstly. The prerequisite to realize the online recognition is proposed and recognition rules for partial flow pattern are obtained based on the massive experimental data. The standard templates for every flow regime feature are calculated with self-organization cluster algorithm. The multi-sensor data fusion method is proposed to realize the online recognition of multiphase flow regime with the pressure and differential pressure signals, which overcomes the severe influence of fluid flow velocity and the oil fraction on the recognition. The online recognition method is tested in the practice, which has less than 10 percent measurement error. The method takes advantages of high confidence, good fault tolerance and less requirement of single sensor performance.

  6. Recognition of Isolated Words using Zernike and MFCC features for Audio Visual Speech Recognition

    OpenAIRE

    Bordea, Prashant; Varpeb, Amarsinh; Manzac, Ramesh; Yannawara, Pravin

    2014-01-01

    Automatic Speech Recognition (ASR) by machine is an attractive research topic in signal processing domain and has attracted many researchers to contribute in this area. In recent year, there have been many advances in automatic speech reading system with the inclusion of audio and visual speech features to recognize words under noisy conditions. The objective of audio-visual speech recognition system is to improve recognition accuracy. In this paper we computed visual features using Zernike m...

  7. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  8. Bacterial fucose-rich polysaccharide stabilizes MAPK-mediated Nrf2/Keap1 signaling by directly scavenging reactive oxygen species during hydrogen peroxide-induced apoptosis of human lung fibroblast cells.

    Directory of Open Access Journals (Sweden)

    Sougata Roy Chowdhury

    Full Text Available Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2-induced stress in human lung fibroblast (WI38 cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼ 42% conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and (1H/(13C/2D-COSY NMR. H2O2 (300 µM insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases. Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities.

  9. Bacterial fucose-rich polysaccharide stabilizes MAPK-mediated Nrf2/Keap1 signaling by directly scavenging reactive oxygen species during hydrogen peroxide-induced apoptosis of human lung fibroblast cells.

    Science.gov (United States)

    Roy Chowdhury, Sougata; Sengupta, Suman; Biswas, Subir; Sinha, Tridib Kumar; Sen, Ramkrishna; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2014-01-01

    Continuous free radical assault upsets cellular homeostasis and dysregulates associated signaling pathways to promote stress-induced cell death. In spite of the continuous development and implementation of effective therapeutic strategies, limitations in treatments for stress-induced toxicities remain. The purpose of the present study was to determine the potential therapeutic efficacy of bacterial fucose polysaccharides against hydrogen peroxide (H2O2)-induced stress in human lung fibroblast (WI38) cells and to understand the associated molecular mechanisms. In two different fermentation processes, Bacillus megaterium RB-05 biosynthesized two non-identical fucose polysaccharides; of these, the polysaccharide having a high-fucose content (∼ 42%) conferred the maximum free radical scavenging efficiency in vitro. Structural characterizations of the purified polysaccharides were performed using HPLC, GC-MS, and (1)H/(13)C/2D-COSY NMR. H2O2 (300 µM) insult to WI38 cells showed anti-proliferative effects by inducing intracellular reactive oxygen species (ROS) and by disrupting mitochondrial membrane permeability, followed by apoptosis. The polysaccharide (250 µg/mL) attenuated the cell death process by directly scavenging intracellular ROS rather than activating endogenous antioxidant enzymes. This process encompasses inhibition of caspase-9/3/7, a decrease in the ratio of Bax/Bcl2, relocalization of translocated Bax and cytochrome c, upregulation of anti-apoptotic members of the Bcl2 family and a decrease in the phosphorylation of MAPKs (mitogen activated protein kinases). Furthermore, cellular homeostasis was re-established via stabilization of MAPK-mediated Nrf2/Keap1 signaling and transcription of downstream cytoprotective genes. This molecular study uniquely introduces a fucose-rich bacterial polysaccharide as a potential inhibitor of H2O2-induced stress and toxicities.

  10. Corrosion Acoustic Emission Signal Recognition Based on Relevance Vector Machine Model%基于相关向量机模型的腐蚀声发射信号识别

    Institute of Scientific and Technical Information of China (English)

    马佳良; 于洋

    2014-01-01

    The classification performance of the RVM model and its associated kernel function parameter are closely related. This paper applies artificial bee colony algorithm (ABC), particle swarm optimization (PSO) and genetic algorithm (GA) to find the optimal parameter of the RVM model, and the performance of these methods was compared. Based on the binary tree structure and one-against-all method, the binary-classification RVM model is extended to establish a four-classification model. The tank bottom corrosion acoustic emission signals were recognized using the established model. The characteristics parameters of the acoustic emission signal and the frequency-domain parameters were selected as the input parameters of the model, and a good recognition was obtained.%相关向量机(RVM)模型的分类性能与其核函数参数的选择有密切关系。本文分别利用人工蜂群算法(ABC)、粒子群算法(PSO)和遗传算法(GA)寻找相关向量机模型的最优参数,对几种方法的寻优性能进行了对比。采用基于二叉树结构的一对多扩展方法,对二分类相关向量机模型进行了扩展,建立了四分类模型。基于该分类模型对罐底腐蚀声发射信号进行识别,将声发射特征参数和频域参数作为模型的输入参数,获得了较好的识别结果。

  11. The epithelial αvβ3-integrin boosts the MYD88-dependent TLR2 signaling in response to viral and bacterial components.

    Directory of Open Access Journals (Sweden)

    Tatiana Gianni

    2014-11-01

    Full Text Available TLR2 is a cell surface receptor which elicits an immediate response to a wide repertoire of bacteria and viruses. Its response is usually thought to be proinflammatory rather than an antiviral. In monocytic cells TLR2 cooperates with coreceptors, e.g. CD14, CD36 and αMβ2-integrin. In an earlier work we showed that αvβ3-integrin acts in concert with TLR2 to elicit an innate response to HSV, and to lipopolysaccharide. This response is characterized by production of IFN-α and -β, a specific set of cytokines, and NF-κB activation. We investigated the basis of the cooperation between αvβ3-integrin and TLR2. We report that β3-integrin participates by signaling through Y residues located in the C-tail, known to be involved in signaling activity. αvβ3-integrin boosts the MYD88-dependent TLR2 signaling and IRAK4 phosphorylation in 293T and in epithelial, keratinocytic and neuronal cell lines. The replication of ICP0minus HSV is greatly enhanced by DN versions of MYD88, of Akt - a hub of this pathway, or by β3integrin-silencing. αvβ3-integrin enables the recruitment of TLR2, MAL, MYD88 at lipid rafts, the platforms from where the signaling starts. The PAMP of the HSV-induced innate response is the gH/gL virion glycoprotein, which interacts with αvβ3-integrin and TLR2 independently one of the other, and cross-links the two receptors. Given the preferential distribution of αvβ3-integrin to epithelial cells, we propose that αvβ3-integrin serves as coreceptor of TLR2 in these cells. The results open the possibility that TLR2 makes use of coreceptors in a variety of cells to broaden its spectrum of activity and tissue specificity.

  12. Haemodynamic effects of the bacterial quorum sensing signal molecule, N-(3-oxododecanoyl)-L-homoserine lactone, in conscious, normal and endotoxaemic rats

    OpenAIRE

    Gardiner, S. M.; Chhabra, S.R.; Harty, C; Williams, P; Pritchard, D I; Bycroft, B W; Bennett, T.

    2001-01-01

    N-acylhomoserine lactones (AHLs) are small, diffusible signalling molecules, employed by Gram-negative bacteria to coordinate gene expression with cell population density. Recent in vitro findings indicate that AHLs may function as virulence determinants per se, through modification of cytokine production by eukaryotic cells, and by stimulating the relaxation of blood vessels.In the present study, we assessed the influence of AHLs on cardiovascular function in conscious rats, and draw attenti...

  13. Research Progress of Bacterial Signaling Molecule of Antibiotics Re-sistance Mechanism%细菌信号小分子耐药机制的相关研究进展

    Institute of Scientific and Technical Information of China (English)

    易胜杰; 谢靖; 邱少富; 宋宏彬

    2015-01-01

    细菌耐药性问题已逐渐成为社会广泛关注的问题。然而,可运用于临床的新型抗生素却十分匮乏。这主要是因为细菌的耐药机制极其复杂,我们对细菌耐药机制的理解不够全面和深入。近几年,多种生物小分子被发现能够使细菌获得广谱的耐药性,并被证明是广泛存在于细菌中的一种耐药机制,这是对目前细菌耐药理论和模型的一个非常重要的补充,更有助于在抗生素的研发过程中寻找新的作用靶标。我们通过总结分析一氧化氮、硫化氢及吲哚这3种信号小分子与细菌耐药的相关研究进展,探讨信号小分子使细菌获得耐药性的相关机制。%The problem of bacterial resistance has become the social widespread concern. However, the new anti⁃biotics in the clinical application are very scarce. Our understanding of the mechanisms of bacterial resistance is not comprehensive and in-depth enough mainly because they are very complicated. But in recent years, a variety of small signaling molecule are found to make bacteria drug resistance against broad spectrum antibiotics which is shown to be widely existed in bacteria as a mechanism of resistance. It is a very important supplement to bacteri⁃al resistance theory and model at present, and more conducive to choose appropriate targets in the development process of new antibiotics. In this review, we summarized and analyzed the correlation and mechanism of bacterial resistance and small signaling molecule including nitric oxide, hydrogen sulfide and indole.

  14. Interspecific aggression and character displacement of competitor recognition in Hetaerina damselflies

    OpenAIRE

    Anderson, C. N; Grether, G. F.

    2009-01-01

    In zones of sympatry between closely related species, species recognition errors in a competitive context can cause character displacement in agonistic signals and competitor recognition functions, just as species recognition errors in a mating context can cause character displacement in mating signals and mate recognition. These two processes are difficult to distinguish because the same traits can serve as both agonistic and mating signals. One solution is to test for sympatric shifts in re...

  15. Recognition of Fruit Maturity—Based on Near Infrared Signal Processing%果实成熟度识别机器人设计—基于近红外线信号处理

    Institute of Scientific and Technical Information of China (English)

    何婕; 罗妤

    2016-01-01

    In order to improve the picking robot automatic identification of fruit maturity level of intelligence , improve fruit recognition accuracy , robot self localization and automatic planning path capacity design a new automatic picking ro-bot , the robot using image segmentation technique and near infrared signal processing technology , to realize the automatic positioning of fruit maturity and discriminant .The performance of the picking robot was tested , including the segmenta-tion and extraction of the apple image , the judgment of the fruit maturity and the path planning of the robot .Through the test found that the robot can be in complex picking background accurate recognition of apple fruit , and can be in infrared light to achieve the identification of fruit maturity .Finally , plan out the reasonable picking path , to obtain the fruit of ac-curate picking , for the fruit picking robot research provides a valuable reference .%为了提高采摘机器人自动识别果实成熟度的智能化水平,提高果实识别的准确性,实现机器人自主定位和自动规划路径能力,设计了一种新的自动化采摘机器人. 该机器人利用图像分割技术和近红外信号处理技术,实现了果实成熟度的自动定位和判别. 对采摘机器人的性能进行了测试,包括苹果图像的分割和提取、果实成熟度的判断和机器人路径规划. 通过测试发现:机器人可以在复杂采摘背景下准确地识别苹果果实,并可以通过红外线探测实现果实成熟度的判别,最终规划出来合理的采摘路径,实现果实的精准采摘,为果蔬采摘机器人的研究提供了较有价值的参考.

  16. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion...... is the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental parameters......, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to significantly...

  17. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  18. The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation.

    Directory of Open Access Journals (Sweden)

    Vardis Ntoukakis

    2013-01-01

    Full Text Available The major virulence strategy of phytopathogenic bacteria is to secrete effector proteins into the host cell to target the immune machinery. AvrPto and AvrPtoB are two such effectors from Pseudomonas syringae, which disable an overlapping range of kinases in Arabidopsis and Tomato. Both effectors target surface-localized receptor-kinases to avoid bacterial recognition. In turn, tomato has evolved an intracellular effector-recognition complex composed of the NB-LRR protein Prf and the Pto kinase. Structural analyses have shown that the most important interaction surface for AvrPto and AvrPtoB is the Pto P+1 loop. AvrPto is an inhibitor of Pto kinase activity, but paradoxically, this kinase activity is a prerequisite for defense activation by AvrPto. Here using biochemical approaches we show that disruption of Pto P+1 loop stimulates phosphorylation in trans, which is possible because the Pto/Prf complex is oligomeric. Both P+1 loop disruption and transphosphorylation are necessary for signalling. Thus, effector perturbation of one kinase molecule in the complex activates another. Hence, the Pto/Prf complex is a sophisticated molecular trap for effectors that target protein kinases, an essential aspect of the pathogen's virulence strategy. The data presented here give a clear view of why bacterial virulence and host recognition mechanisms are so often related and how the slowly evolving host is able to keep pace with the faster-evolving pathogen.

  19. The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation.

    Science.gov (United States)

    Ntoukakis, Vardis; Balmuth, Alexi L; Mucyn, Tatiana S; Gutierrez, Jose R; Jones, Alexandra M E; Rathjen, John P

    2013-01-01

    The major virulence strategy of phytopathogenic bacteria is to secrete effector proteins into the host cell to target the immune machinery. AvrPto and AvrPtoB are two such effectors from Pseudomonas syringae, which disable an overlapping range of kinases in Arabidopsis and Tomato. Both effectors target surface-localized receptor-kinases to avoid bacterial recognition. In turn, tomato has evolved an intracellular effector-recognition complex composed of the NB-LRR protein Prf and the Pto kinase. Structural analyses have shown that the most important interaction surface for AvrPto and AvrPtoB is the Pto P+1 loop. AvrPto is an inhibitor of Pto kinase activity, but paradoxically, this kinase activity is a prerequisite for defense activation by AvrPto. Here using biochemical approaches we show that disruption of Pto P+1 loop stimulates phosphorylation in trans, which is possible because the Pto/Prf complex is oligomeric. Both P+1 loop disruption and transphosphorylation are necessary for signalling. Thus, effector perturbation of one kinase molecule in the complex activates another. Hence, the Pto/Prf complex is a sophisticated molecular trap for effectors that target protein kinases, an essential aspect of the pathogen's virulence strategy. The data presented here give a clear view of why bacterial virulence and host recognition mechanisms are so often related and how the slowly evolving host is able to keep pace with the faster-evolving pathogen.

  20. Behind the lines–actions of bacterial type III effector proteins in plant cells

    Science.gov (United States)

    Büttner, Daniela

    2016-01-01

    Pathogenicity of most Gram-negative plant-pathogenic bacteria depends on the type III secretion (T3S) system, which translocates bacterial effector proteins into plant cells. Type III effectors modulate plant cellular pathways to the benefit of the pathogen and promote bacterial multiplication. One major virulence function of type III effectors is the suppression of plant innate immunity, which is triggered upon recognition of pathogen-derived molecular patterns by plant receptor proteins. Type III effectors also interfere with additional plant cellular processes including proteasome-dependent protein degradation, phytohormone signaling, the formation of the cytoskeleton, vesicle transport and gene expression. This review summarizes our current knowledge on the molecular functions of type III effector proteins with known plant target molecules. Furthermore, plant defense strategies for the detection of effector protein activities or effector-triggered alterations in plant targets are discussed. PMID:27526699

  1. Physics of Automatic Target Recognition

    CERN Document Server

    Sadjadi, Firooz

    2007-01-01

    Physics of Automatic Target Recognition addresses the fundamental physical bases of sensing, and information extraction in the state-of-the art automatic target recognition field. It explores both passive and active multispectral sensing, polarimetric diversity, complex signature exploitation, sensor and processing adaptation, transformation of electromagnetic and acoustic waves in their interactions with targets, background clutter, transmission media, and sensing elements. The general inverse scattering, and advanced signal processing techniques and scientific evaluation methodologies being used in this multi disciplinary field will be part of this exposition. The issues of modeling of target signatures in various spectral modalities, LADAR, IR, SAR, high resolution radar, acoustic, seismic, visible, hyperspectral, in diverse geometric aspects will be addressed. The methods for signal processing and classification will cover concepts such as sensor adaptive and artificial neural networks, time reversal filt...

  2. Speaker recognition by voice

    OpenAIRE

    Kamarauskas, Juozas

    2009-01-01

    Questions of speaker’s recognition by voice are investigated in this dissertation. Speaker recognition systems, their evolution, problems of recognition, systems of features, questions of speaker modeling and matching used in text-independent and text-dependent speaker recognition are considered too. The text-independent speaker recognition system has been developed during this work. The Gaussian mixture model approach was used for speaker modeling and pattern matching. The automatic m...

  3. Iris Recognition Technique

    Institute of Scientific and Technical Information of China (English)

    XIE Mei

    2006-01-01

    The demand on security is increasing greatly in these years and biometric recognition gradually becomes a hot field of research. Iris recognition is a new branch of biometric recognition, which is regarded as the most stable, safe and accurate biometric recognition method. In these years, much progress in this field has been made by scholars and experts of different countries. In this paper, some successful iris recognition methods are listed and their performance are compared. Furthermore, the existing problems and challenges are discussed.

  4. Pattern recognition for earthquake detection

    OpenAIRE

    Joswig, Manfred

    1990-01-01

    The detector algorithms in use at date rely on negative decision logic: based on a model of the ambient noise process they detect all deviations, but many of them are false alarms. The principal alternative to this approach is pattern recognition, which tests on positive correlation with some known signal patterns. The Sonogram-detector realizes this scheme for single seismogram traces. Sonograms display spectral energy versus time. Suitably scaled, these images display only information wh...

  5. Bacterial meningitis: Mechanisms of disease and therapy

    NARCIS (Netherlands)

    R.F. Kornelisse (René); R. de Groot (Ronald); H.J. Neijens (Herman)

    1995-01-01

    textabstractBacterial meningitis continues to be a serious infectious disease with a high morbidity and mortality in young children. Early recognition and initiation of adequate treatment are the major determinants for a good outcome. Recent advances in our understanding of the host inflammatory res

  6. Oyster Electrophysiology: Electrocardiogram Signal Recognition and Interpretation

    OpenAIRE

    Frederico M Batista; Deborah M Power; Harrison, Adrian P.

    2015-01-01

    After 100 years of published recording traces pertaining to the oyster electrocardiogram (ECG), we revisited the original experiments of Eiger (1913), using state-of-the-art electrophysiology recorders. Our aim was to confirm that a recordable ECG, similar to that of higher vertebrates, is present in the oyster heart. Portuguese oysters Crassostrea angulata, collected from the Guadiana estuary, Portugal, were used. The oysters were drilled through the right valve to reveal the pericardium. Go...

  7. 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.

  8. Direct ubiquitination of pattern recognition receptor FLS2 attenuates plant innate immunity

    Science.gov (United States)

    Lu, Dongping; Lin, Wenwei; Gao, Xiquan; Wu, Shujing; Cheng, Cheng; Avila, Julian; Heese, Antje; Devarenne, Timothy P.; He, Ping; Shan, Libo

    2011-01-01

    Innate immune responses are triggered by the activation of pattern-recognition receptors (PRRs). The Arabidopsis PRR FLS2 senses bacterial flagellin and initiates immune signaling by association with BAK1. The molecular mechanisms underlying the attenuation of FLS2 activation are largely unknown. We report that flagellin induces recruitment of two closely related U-box E3 ubiquitin ligases PUB12 and PUB13 to FLS2 receptor complex in Arabidopsis. BAK1 phosphorylates PUB12/13 and is required for FLS2-PUB12/13 association. PUB12/13 polyubiquitinate FLS2 and promote flagellin-induced FLS2 degradation, and the pub12 and pub13 mutants displayed elevated immune responses to flagellin treatment. Our study has revealed a unique regulatory circuit of direct ubiquitination and turnover of FLS2 by BAK1-mediated phosphorylation and recruitment of specific E3 ligases for attenuation of immune signaling. PMID:21680842

  9. 架空线-电缆混合线路故障行波信号识别的研究%Research on Signal Recognition of Fault Traveling Wave for Cable-Overhead Mixed Line

    Institute of Scientific and Technical Information of China (English)

    王升; 徐伟

    2016-01-01

    ABSTRACT:This paper deals with fault recognition of the cable-overhead mixed line. With focus on the high resistance instantaneous ground fault and overhead line lightning fault of the mixed line,the paper proposes that the spectrum energy ratio of two characteristic frequency bands and waveform factor in the fault current traveling wave be used to distinguish non lightning strike fault,lightning fault and high impedance arc ground fault. The simulation model of the electromagnetic transient software is used to simulate the lightning strike on the cable-overhead mixed line;meanwhile, the fault traveling wave signal is identified. The simulation results show that the method proposed can effectively identify three kinds of faults.%针对架空-电缆混合线路中的高阻瞬时接地故障和架空线路雷击故障,提出采用电流故障行波的2个特征频带中的频谱能量比和波形系数来有效区分雷击非故障与雷击故障、高阻弧光接地故障的思想。利用电磁暂态软件建立仿真模型对架空-电缆混合线路的各种雷击情况进行了仿真,并且对故障行波信号进行了识别研究。仿真结果表明,采用的雷击识别方法可以有效识别不同类型的故障。

  10. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...... biogeochemical processes are carried exclusively by bacteria. * Bacteria play an important role in all types of habitats including some that cannot support eukaryotic life....

  11. A MyD88-dependent IFNγR-CCR2 signaling circuit is required for mobilization of monocytes and host defense against systemic bacterial challenge

    Institute of Scientific and Technical Information of China (English)

    Eric M Pietras; Lloyd S Miller; Carl T Johnson; Ryan M O'Connell; Paul W Dempsey; Genhong Cheng

    2011-01-01

    Monocytes are mobilized to sites of infection via interaction between the chemokine MCP-1 and its receptor, CCR2, at which point they differentiate into macrophages that mediate potent antimicrobial effects. In this study, we investigated the mechanisms by which monocytes are mobilized in response to systemic challenge with the intracellular bacterium Francisella tularensis. We found that mice deficient in MyD88, interferon-γ (IFNγ)R or CCR2 all had defects in the expansion of splenic monocyte populations upon F. tularensis challenge, and in control of F. tularensis infection. Interestingly, MyD88-deficient mice were defective in production of IFNγ, and IFNγR deficient mice exhibited defective production of MCP-1, the ligand for CCR2. Transplantation of IFNγR-deficient bone marrow (BM) into wild-type mice further suggested that mobilization of monocytes in response to F. tularensis challenge required IFNγR expression on BM-derived cells. These studies define a critical host defense circuit wherein MyD88-dependent IFNγ production signals via IFNγR expressed on BM-derived cells, resulting in MCP-1 production and activation of CCR2-dependent mobilization of monocytes in the innate immune response to systemic F. tularensis challenge.

  12. Cross-talk between a regulatory small RNA, cyclic-di-GMP signalling and flagellar regulator FlhDC for virulence and bacterial behaviours.

    Science.gov (United States)

    Yuan, Xiaochen; Khokhani, Devanshi; Wu, Xiaogang; Yang, Fenghuan; Biener, Gabriel; Koestler, Benjamin J; Raicu, Valerica; He, Chenyang; Waters, Christopher M; Sundin, George W; Tian, Fang; Yang, Ching-Hong

    2015-11-01

    Dickeya dadantii is a globally dispersed phytopathogen which causes diseases on a wide range of host plants. This pathogen utilizes the type III secretion system (T3SS) to suppress host defense responses, and secretes pectate lyase (Pel) to degrade the plant cell wall. Although the regulatory small RNA (sRNA) RsmB, cyclic diguanylate monophosphate (c-di-GMP) and flagellar regulator have been reported to affect the regulation of these two virulence factors or multiple cell behaviours such as motility and biofilm formation, the linkage between these regulatory components that coordinate the cell behaviours remain unclear. Here, we revealed a sophisticated regulatory network that connects the sRNA, c-di-GMP signalling and flagellar master regulator FlhDC. We propose multi-tiered regulatory mechanisms that link the FlhDC to the T3SS through three distinct pathways including the FlhDC-FliA-YcgR3937 pathway; the FlhDC-EcpC-RpoN-HrpL pathway; and the FlhDC-rsmB-RsmA-HrpL pathway. Among these, EcpC is the most dominant factor for FlhDC to positively regulate T3SS expression.

  13. Novel anti-bacterial activities of β-defensin 1 in human platelets: suppression of pathogen growth and signaling of neutrophil extracellular trap formation.

    Directory of Open Access Journals (Sweden)

    Bjoern F Kraemer

    2011-11-01

    Full Text Available Human β-defensins (hBD are antimicrobial peptides that curb microbial activity. Although hBD's are primarily expressed by epithelial cells, we show that human platelets express hBD-1 that has both predicted and novel antibacterial activities. We observed that activated platelets surround Staphylococcus aureus (S. aureus, forcing the pathogens into clusters that have a reduced growth rate compared to S. aureus alone. Given the microbicidal activity of β-defensins, we determined whether hBD family members were present in platelets and found mRNA and protein for hBD-1. We also established that hBD-1 protein resided in extragranular cytoplasmic compartments of platelets. Consistent with this localization pattern, agonists that elicit granular secretion by platelets did not readily induce hBD-1 release. Nevertheless, platelets released hBD-1 when they were stimulated by α-toxin, a S. aureus product that permeabilizes target cells. Platelet-derived hBD-1 significantly impaired the growth of clinical strains of S. aureus. hBD-1 also induced robust neutrophil extracellular trap (NET formation by target polymorphonuclear leukocytes (PMNs, which is a novel antimicrobial function of β-defensins that was not previously identified. Taken together, these data demonstrate that hBD-1 is a previously-unrecognized component of platelets that displays classic antimicrobial activity and, in addition, signals PMNs to extrude DNA lattices that capture and kill bacteria.

  14. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  15. Robust Facial Expression Recognition via Compressive Sensing

    OpenAIRE

    Shiqing Zhang; Xiaoming Zhao; Bicheng Lei

    2012-01-01

    Recently, compressive sensing (CS) has attracted increasing attention in the areas of signal processing, computer vision and pattern recognition. In this paper, a new method based on the CS theory is presented for robust facial expression recognition. The CS theory is used to construct a sparse representation classifier (SRC). The effectiveness and robustness of the SRC method is investigated on clean and occluded facial expression images. Three typical facial features, i.e., the raw pixels, ...

  16. Pattern recognition using linguistic fuzzy logic predictors

    Science.gov (United States)

    Habiballa, Hashim

    2016-06-01

    The problem of pattern recognition has been solved with numerous methods in the Artificial Intelligence field. We present an unconventional method based on Lingustic Fuzzy Logic Forecaster which is primarily used for the task of time series analysis and prediction through logical deduction wtih linguistic variables. This method should be used not only to the time series prediction itself, but also for recognition of patterns in a signal with seasonal component.

  17. Analysis of Human Electrocardiogram for Biometric Recognition

    OpenAIRE

    Konstantinos N. Plataniotis; Dimitrios Hatzinakos; Foteini Agrafioti; Yongjin Wang

    2007-01-01

    Security concerns increase as the technology for falsification advances. There are strong evidences that a difficult to falsify biometric trait, the human heartbeat, can be used for identity recognition. Existing solutions for biometric recognition from electrocardiogram (ECG) signals are based on temporal and amplitude distances between detected fiducial points. Such methods rely heavily on the accuracy of fiducial detection, which is still an open problem due to the difficulty in exact loca...

  18. Prevention of bacterial foodborne disease using nanobiotechnology

    Directory of Open Access Journals (Sweden)

    Billington C

    2014-08-01

    Full Text Available Craig Billington, J Andrew Hudson, Elaine D'SaFood Safety Programme, ESR, Ilam, Christchurch, New Zealand Abstract: Foodborne disease is an important source of expense, morbidity, and mortality for society. Detection and control constitute significant components of the overall management of foodborne bacterial pathogens, and this review focuses on the use of nanosized biological entities and molecules to achieve these goals. There is an emphasis on the use of organisms called bacteriophages (phages: viruses that infect bacteria, which are increasingly being used in pathogen detection and biocontrol applications. Detection of pathogens in foods by conventional techniques is time-consuming and expensive, although it can also be sensitive and accurate. Nanobiotechnology is being used to decrease detection times and cost through the development of biosensors, exploiting specific cell-recognition properties of antibodies and phage proteins. Although sensitivity per test can be excellent (eg, the detection of one cell, the very small volumes tested mean that sensitivity per sample is less compelling. An ideal detection method needs to be inexpensive, sensitive, and accurate, but no approach yet achieves all three. For nanobiotechnology to displace existing methods (culture-based, antibody-based rapid methods, or those that detect amplified nucleic acid it will need to focus on improving sensitivity. Although manufactured nonbiological nanoparticles have been used to kill bacterial cells, nanosized organisms called phages are increasingly finding favor in food safety applications. Phages are amenable to protein and nucleic acid labeling, and can be very specific, and the typical large "burst size" resulting from phage amplification can be harnessed to produce a rapid increase in signal to facilitate detection. There are now several commercially available phages for pathogen control, and many reports in the literature demonstrate efficacy against a

  19. 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

  20. Acoustic Pattern Recognition on Android Devices

    DEFF Research Database (Denmark)

    Møller, Maiken Bjerg; Gaarsdal, Jesper; Steen, Kim Arild;

    2013-01-01

    an Android application developed for acoustic pattern recognition of bird species. The acoustic data is recorded using a built-in microphone, and pattern recognition is performed on the device, requiring no network connection. The algorithm is implemented in C++ as a native Android module and the Open......CV library is used for signal processing. We conclude that the approach presented here is a viable solution to pattern recognition problems. Since it requires no network connection, it shows promise in fields such as wildlife research....

  1. 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.

  2. Bacteriophages as recognition and identification agents

    Energy Technology Data Exchange (ETDEWEB)

    Teodorescu, M.C.; Gaspar, A.

    1987-04-23

    Bacteriophages are employed as agents for recognition and identification of molecules and cellular materials, using their ability to recognize their bacterial host, by coating them with antibodies or by selecting them to perform in a manner analogous to antibodies. Visibility for identification is effected by incorporating a fluorescent agent, a radioisotope, a metal, an enzyme, or other staining material. The method of this invention may be utilized in selected clinical procedures, and is adaptable to use in an assay kit.

  3. RECOGNITION OF CONTESTED STATES

    OpenAIRE

    Ali, Nanna; Ben-Ahmed, Michele; Bom, Thomas Falk; Ching, Rune Kieran; Steffensen, Lars Schmidt; Funningsstovu, Janus Hanusarson í

    2012-01-01

    Contested states have existed in many decades and been on the political agenda worldwide. A small group of entities in the world are aspiring for recognition and independence, while some entities gained recognition relatively smoothly. This project accounts for UN’s recognition process and investigates entities prospects of influencing the process for obtaining recognition. Based on theories of liberalism and constructivism as well as the opposing theories of international relations, re...

  4. Recognition and Teleportation

    OpenAIRE

    Fichtner, K. -H.; Freudenberg, W.; Ohya, M.

    2004-01-01

    We study a possible function of brain, in particular, we try to describe several aspects of the process of recognition. In order to understand the fundamental parts of the recognition process, the quantum teleportation scheme seems to be useful. We consider a channel expression of the teleportation process that serves for a simplified description of the recognition process in brain.

  5. Cyclic enterobacterial common antigen: Potential contaminant of bacterially expressed protein preparations

    International Nuclear Information System (INIS)

    We have previously reported the identification of the cyclic enterobacterial common antigen (ECACYC) polysaccharide in E. coli strains commonly used for heterologous protein expression (PJA Erbel et al., J. Bacteriol.185 (2003): 1995). Following this initial report, interactions among several NMR groups established that characteristic N-acetyl signals of ECACYC have been observed in 15N-1H HSQC spectra of samples of various bacterially-expressed proteins suggesting that this water-soluble carbohydrate is a common contaminant. We provide NMR spectroscopic tools to recognize ECACYC in protein samples, as well as several methods to remove this contaminant. Early recognition of ECA-based NMR signals will prevent time-consuming analyses of this copurifying carbohydrate

  6. 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...

  7. Bacterial Hydrodynamics

    Science.gov (United States)

    Lauga, Eric

    2016-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells, yet they represent the bulk of the world's biomass and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micrometer scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically complex environments. Using hydrodynamics as an organizing framework, I review the biomechanics of bacterial motility and look ahead to future challenges.

  8. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  9. Transcriptional response of Musca domestica larvae to bacterial infection.

    Directory of Open Access Journals (Sweden)

    Ting Tang

    Full Text Available The house fly Musca domestica, a cosmopolitan dipteran insect, is a significant vector for human and animal bacterial pathogens, but little is known about its immune response to these pathogens. To address this issue, we inoculated the larvae with a mixture of Escherichia coli and Staphylococcus aureus and profiled the transcriptome 6, 24, and 48 h thereafter. Many genes known to controlling innate immunity in insects were induced following infection, including genes encoding pattern recognition proteins (PGRPs, various components of the Toll and IMD signaling pathways and of the proPO-activating and redox systems, and multiple antimicrobial peptides. Interestingly, we also uncovered a large set of novel immune response genes including two broad-spectrum antimicrobial peptides (muscin and domesticin, which might have evolved to adapt to house-fly's unique ecological environments. Finally, genes mediating oxidative phosphorylation were repressed at 48 h post-infection, suggesting disruption of energy homeostasis and mitochondrial function at the late stages of infection. Collectively, our data reveal dynamic changes in gene expression following bacterial infection in the house fly, paving the way for future in-depth analysis of M. domestica's immune system.

  10. Pattern Recognition and Event Reconstruction in Particle Physics Experiments

    OpenAIRE

    Mankel, Rainer

    2004-01-01

    This report reviews methods of pattern recognition and event reconstruction used in modern high energy physics experiments. After a brief introduction into general concepts of particle detectors and statistical evaluation, different approaches in global and local methods of track pattern recognition are reviewed with their typical strengths and shortcomings. The emphasis is then moved to methods which estimate the particle properties from the signals which pattern recognition has associated. ...

  11. Radar target recognition based on micro-Doppler effect

    Institute of Scientific and Technical Information of China (English)

    DONG Wei-guang; LI Yan-jun

    2008-01-01

    Mechanical vibration of target structures will modulate the phase function of radar backscattering, and will induce thefrequency modulation of returned signals from the target. It generates a side bands of the target body Doppler frequencyshift, which is helpful for target recognition. Based on this.a micro-Doppler atomic storehouse is built for the targetrecognition, and four kinds of common classifiers are used separately to perform the classified recognition. The simulationexperimental results show that this method has high recognition rate above 90%.

  12. Disgust and fear recognition in paraneoplastic limbic encephalitis.

    OpenAIRE

    Sprengelmeyer, R.; A. P. Atkinson; Sprengelmeyer, A; Mair-Walther, J.; Jacobi, C.; Wildemann, B.; Dittrich, W.H.; Hacke, W

    2010-01-01

    Paraneoplastic limbic encephalitis (PNLE) affects limbic portions of the brain associated with recognition of social signals of emotions. Yet it is not known whether this perceptual ability is impaired in individuals with PNLE. We therefore conducted a single case study to explore possible impairments in recognising facially, vocally, and bodily expressed emotions, using standardised emotion recognition tests. Facial expression recognition was tested with two forced-choice emotion-labelling t...

  13. Embedded system for individual recognition based on ECG biometrics

    OpenAIRE

    Matos, André Cigarro; Lourenço, André Ribeiro; Nascimento, José M. P.

    2014-01-01

    Biometric recognition is emerging has an alternative solution for applications where the privacy of the information is crucial. This paper presents an embedded biometric recognition system based on the Electrocardiographic signals (ECG) for individual identification and authentication. The proposed system implements a real-time state-of-the-art recognition algorithm, which extracts information from the frequency domain. The system is based on a ARM Cortex 4. Preliminary results show ...

  14. Facial Expression Recognition based on Independent Component Analysis

    OpenAIRE

    XiaoHui Guo; Xiao Zhang; Chao Deng; Jianyu Wei

    2013-01-01

    As an important part of artificial intelligence and pattern recognition, facial expression recognition has drawn much attention recently and numerous methods have been proposed. Feature extraction is the most important part which directly affects the final recognition results. Independent component analysis (ICA) is a subspace analysis method, which is also a novel statistical technique in signal processing and machine learning that aims at finding linear projections of the data that maximize...

  15. Window Size Impact in Human Activity Recognition

    Directory of Open Access Journals (Sweden)

    Oresti Banos

    2014-04-01

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

  16. Fuzzy Neural Model for Flatness Pattern Recognition

    Institute of Scientific and Technical Information of China (English)

    JIA Chun-yu; SHAN Xiu-ying; LIU Hong-min; NIU Zhao-ping

    2008-01-01

    For the problems occurring in a least square method model,a fuzzy model,and a neural network model for flatness pattern recognition,a fuzzy neural network model for flatness pattern recognition with only three-input and three-output signals was proposed with Legendre orthodoxy polynomial as basic pattern,based on fuzzy logic expert experiential knowledge and genetic-BP hybrid optimization algorithm.The model not only had definite physical meanings in its inner nodes,but also had strong self-adaptability,anti-interference ability,high recognition precision,and high velocity,thereby meeting the demand of high-precision flatness control for cold strip mill and providing a convenient,practical,and novel method for flatness pattern recognition.

  17. Normal ECG Recognition for Express-Diagnostics Based on Scale-Space Representation and Dynamic Matching

    OpenAIRE

    Bilous, Nataliya; Bondarenko, Michael; Kobzar, Gleb; Krasov, Alexey; Rogozyanov, Artyom

    2008-01-01

    A novel approach of normal ECG recognition based on scale-space signal representation is proposed. The approach utilizes curvature scale-space signal representation used to match visual objects shapes previously and dynamic programming algorithm for matching CSS representations of ECG signals. Extraction and matching processes are fast and experimental results show that the approach is quite robust for preliminary normal ECG recognition.

  18. 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.

  19. Phosphorylation of bacterial-type phosphoenolpyruvate carboxylase by a Ca2+-dependent protein kinase suggests a link between Ca2+ signalling and anaplerotic pathway control in developing castor oil seeds.

    Science.gov (United States)

    Hill, Allyson T; Ying, Sheng; Plaxton, William C

    2014-02-15

    The aim of the present study was to characterize the native protein kinase [BTPC (bacterial-type phosphoenolpyruvate carboxylase)-K (BTPC Ser451 kinase)] that in vivo phosphorylates Ser451 of the BTPC subunits of an unusual Class-2 PEP (phosphoenolpyruvate) carboxylase hetero-octameric complex of developing COS (castor oil seeds). COS BTPC-K was highly purified by PEG fractionation and hydrophobic size-exclusion anion-exchange and affinity chromatographies. BTPC-K phosphorylated BTPC strictly at Ser451 (Km=1.0 μM; pH optimum=7.3), a conserved target residue occurring within an intrinsically disordered region, as well as the protein histone III-S (Km=1.7 μM), but not a COS plant-type PEP carboxylase or sucrose synthase or α-casein. Its activity was Ca2+- (K0.5=2.7 μM) and ATP- (Km=6.6 μM) dependent, and markedly inhibited by trifluoperazine, 3-phosphoglycerate and PEP, but insensitive to calmodulin or 14-3-3 proteins. BTPC-K exhibited a native molecular mass of ~63 kDa and was soluble rather than membrane-bound. Inactivation and reactivation occurred upon BTPC-K's incubation with GSSG and then DTT respectively. Ser451 phosphorylation by BTPC-K inhibited BTPC activity by ~50% when assayed under suboptimal conditions (pH 7.3, 1 mM PEP and 10 mM L-malate). Our collective results indicate a possible link between cytosolic Ca2+ signalling and anaplerotic flux control in developing COS.

  20. Low fucose containing bacterial polysaccharide facilitate mitochondria-dependent ROS-induced apoptosis of human lung epithelial carcinoma via controlled regulation of MAPKs-mediated Nrf2/Keap1 homeostasis signaling.

    Science.gov (United States)

    Chowdhury, Sougata Roy; Sengupta, Suman; Biswas, Subir; Sen, Ramkrishna; Sinha, Tridib Kumar; Basak, Ratan Kumar; Adhikari, Basudam; Bhattacharyya, Arindam

    2015-12-01

    Reactive oxygen species (ROS), the key mediators of cellular oxidative stress and redox dysregulation involved in cancer initiation and progression, have recently emerged as promising targets for anticancer drug discovery. Continuous free radical assault upsets homeostasis in cellular redox system and regulates the associated signaling pathways to mediate stress-induced cell death. This study investigates the dose-specific pro-oxidative behavior of a bacterial fucose polysaccharide, which attenuated proliferation of different cancer cells. In the fermentation process, Bacillus megaterium RB-05 [GenBank Accession Number HM371417] was found to biosynthesize a polysaccharide with low-fucose content (4.9%), which conferred the maximum anti-proliferative activity (750 µg/mL) against human lung cancer epithelial cells (A549) during preliminary screening. Structural elucidation and morphological characterization of the duly purified polysaccharide was done using HPLC, GC-MS, (1)H/(13)C NMR, and microscopy. The polysaccharide exhibited concentration- and time-dependent anti-proliferative effects against A549 cells by inducing intracellular ROS level and regulating the mitochondrial membrane-permeability following the apoptotic pathway. This process encompasses activation of caspase-8/9/3/7, increase in the ratio of Bax/Bcl2 ratio, translocation of Bcl2-associated X protein (Bax) and cytochrome c, decrease in expression of anti-apoptotic members of Bcl2 family, and phosphorylation of mitogen activated protein kinases (MAPKs). Apoptosis was attenuated upon pretreatment with specific caspase-inhibitors. Simultaneously, during apoptosis, the ROS-mediated stress as well as activated MAPKs triggered nuclear translocation of transcription factors like nuclear factor (erythroid-derived)-like 2 (Nrf2) and promoted further transcription of downstream cytoprotective genes, which somehow perturbed the chemotherapeutic efficacy of the polysaccharide, although using CuPP, a chemical

  1. Inductive expression of toll-like receptor 5 (TLR5) and associated downstream signaling molecules following ligand exposure and bacterial infection in the Indian major carp, mrigal (Cirrhinus mrigala).

    Science.gov (United States)

    Basu, M; Swain, B; Maiti, N K; Routray, P; Samanta, M

    2012-01-01

    Toll-like receptors (TLRs) are one of the key components of innate immunity. Among various types of TLRs, TLR5 is involved in recognizing bacterial flagellin and after binding, it triggers myeloid differentiation primary response gene 88 (MyD88)-dependent signaling pathway to induce pro-inflammatory cytokines. In this report, we analyzed the expression profile of TLR5 and its associated downstream signaling molecules like MyD88 and tumor necrosis factor (TNF) receptor-associated factor (TRAF) 6 in the Indian major carp (IMC), mrigal (Cirrhinus mrigala) which is highly commercially important fish species in the Indian subcontinent. Ontogeny analysis of TLR5, MyD88 and TRAF6 revealed constitutive expression of these genes in all embryonic developmental stages, and highlighted the importance of embryonic innate immune defense system in fish. Tissue specific expression analysis of these genes by quantitative real-time PCR (qRT-PCR) revealed their wide distribution in various organs and tissues; highest expression of TLR5 and MyD88 was in liver and TRAF6 was in kidney. Modulation of TLR5, MyD88 and TRAF6 gene expression, and the induction of interleukin (IL)-8 and TNF-α were analyzed in various organs by qRT-PCR following flagellin stimulation, and Aeromonas hydrophila and Edwardsiella tarda infection. In the treated fish, majority of the tested tissues exhibited significant induction of these genes, although with varied intensity among the tissues and with the types of treatments. Among the examined tissues, a significant relationship of TLR5 induction, MyD88 and TRAF6 up-regulation, and enhanced expression of IL-8 and TNF-α gene transcripts was observed in the blood and intestine of both flagellin stimulated and bacteria infected fish. These findings may indicate the involvement of TLR5 in inducing IL-8 and TNF-α, and suggest the important role of TLR5 in augmenting innate immunity in fish in response to pathogenic invasion. This study will enrich the information

  2. Pseudomonas evades immune recognition of flagellin in both mammals and plants

    OpenAIRE

    Bart W Bardoel; Sjoerd van der Ent; Pel, Michiel J. C.; Jan Tommassen; Pieterse, Corné M. J.; van Kessel, Kok P. M.; van Strijp, Jos A. G.

    2011-01-01

    The building blocks of bacterial flagella, flagellin monomers, are potent stimulators of host innate immune systems. Recognition of flagellin monomers occurs by flagellin-specific pattern-recognition receptors, such as Toll-like receptor 5 (TLR5) in mammals and flagellin-sensitive 2 (FLS2) in plants. Activation of these immune systems via flagellin leads eventually to elimination of the bacterium from the host. In order to prevent immune activation and thus favor survival in the host, bacteri...

  3. Multimodal Emotion Recognition Using Multimodal Deep Learning

    OpenAIRE

    Liu, Wei; Zheng, Wei-Long; Lu, Bao-Liang

    2016-01-01

    To enhance the performance of affective models and reduce the cost of acquiring physiological signals for real-world applications, we adopt multimodal deep learning approach to construct affective models from multiple physiological signals. For unimodal enhancement task, we indicate that the best recognition accuracy of 82.11% on SEED dataset is achieved with shared representations generated by Deep AutoEncoder (DAE) model. For multimodal facilitation tasks, we demonstrate that the Bimodal De...

  4. Robust speech recognition using articulatory information

    OpenAIRE

    Kirchhoff, Katrin

    1999-01-01

    Current automatic speech recognition systems make use of a single source of information about their input, viz. a preprocessed form of the acoustic speech signal, which encodes the time-frequency distribution of signal energy. The goal of this thesis is to investigate the benefits of integrating articulatory information into state-of-the art speech recognizers, either as a genuine alternative to standard acoustic representations, or as an additional source of information. Articulatory informa...

  5. An ICA based method for texture recognition

    OpenAIRE

    Fournel, Thierry; Becker, Jean-Marie; Daniela COLTUC; Yann BOUTANT

    2006-01-01

    The method proposed in this paper uses the Independent Component Analysis (ICA) for an application of unsupervised recognition of textures. The analysed texture is modelled by a weighted sum of almost statistically independent random signals that are extracted with FastICA algorithm. Each resulting signal is described by its negentropy, more precisely, by one of the approximations used by FastICA algorithm. The approximated negentropies are sorted into descending order and represented by a cu...

  6. Pattern recognition: recent insights from Dectin-1

    OpenAIRE

    Reid, Delyth M.; Gow, Neil AR; Brown, Gordon D.

    2009-01-01

    The β-glucan receptor Dectin-1 is an archetypical non-toll-like pattern recognition receptor expressed predominantly by myeloid cells, which can induce its own intracellular signalling and can mediate a variety of cellular responses, such as cytokine production. Recent identification of the components of these signalling pathways, such as Syk kinase, CARD9 and Raf-1, has provided novel insights into the molecular mechanisms underlying Dectin-1 function. Furthermore, a broader appreciation of ...

  7. Multimodal eye recognition

    Science.gov (United States)

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

    2010-04-01

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

  8. Structural Mechanisms of Peptide Recognition and Allosteric Modulation of Gene Regulation by the RRNPP Family of Quorum-Sensing Regulators.

    Science.gov (United States)

    Do, Hackwon; Kumaraswami, Muthiah

    2016-07-17

    The members of RRNPP family of bacterial regulators sense population density-specific secreted oligopeptides and modulate the expression of genes involved in cellular processes, such as sporulation, competence, virulence, biofilm formation, conjugative plasmid transfer and antibiotic resistance. Signaling by RRNPP regulators include several steps: generation and secretion of the signaling oligopeptides, re-internalization of the signaling molecules into the cytoplasm, signal sensing by the cytosolic RRNPP regulators, signal-specific allosteric structural changes in the regulators, and interaction of the regulators with their respective regulatory target and gene regulation. The recently determined structures of the RRNPP regulators provide insight into the mechanistic aspects for several steps in this signaling circuit. In this review, we discuss the structural principles underlying peptide specificity, regulatory target recognition, and ligand-induced allostery in RRNPP regulators and its impact on gene regulation. Despite the conserved tertiary structure of these regulators, structural analyses revealed unexpected diversity in the mechanism of activation and molecular strategies that couple the peptide-induced allostery to gene regulation. Although these structural studies provide a sophisticated understanding of gene regulation by RRNPP regulators, much needs to be learned regarding the target DNA binding by yet-to-be characterized RNPP regulators and the several aspects of signaling by Rgg regulators. PMID:27283781

  9. Pattern Recognition of Partial Discharge Ultrasonic Signal for Dry-type Transformer Based on Wavelet Packet Transform%基于小波包变换的干式变压器局部放电超声信号的模式识别

    Institute of Scientific and Technical Information of China (English)

    王永强; 杨东星; 何杰; 马伦; 王自强

    2015-01-01

    为研究干式变压器局部放电超声信号的模式识别,设计制作了针-板、沿面和气隙3种局部放电模型,用超声检测系统得到3种局部放电的超声信号波形数据。运用小波包理论对采集到的局部放电超声信号进行分解,用Shannon熵代价函数来确定最优小波包基,得到最优小波树,提取在最优基下包含绝大部分信息能量的小波包分解系数的统计量作为模式识别的输入特征量,并应用CPN网络分类器进行放电类型的识别,取得了很好的效果。%To study the pattern recognition of partial discharge ultrasonic signal for dry-type transformer, we designed three kinds of partial discharge models, which are needle-plate, surface, and air gap, and we obtained three kinds of partial discharge ultrasonic signal waveforms by ultrasonic test system. The par-tial discharge ultrasonic signal was decomposed by wavelet packet theory, and the optimal wavelet packet basis and the optimal wavelet tree were determined by Shannon entropy cost function. The statistics of wavelet packet decomposition coefficients, which contains majority of information energy under the opti-mal wavelet packet basis, was extracted as an input characteristic parameter for pattern recognition, and the discharge type was identified by CPN network classifier. The recognition effect is excellent.

  10. ANATOMY ON PATTERN RECOGNITION

    OpenAIRE

    MAYANK PARASHER; SHRUTI SHARMA; A .K. SHARMA,; J.P.Gupta

    2011-01-01

    Pattern Recognition is the science of recognizing patterns by machines. This is very wide research area as of today, because every newresearch tries to make machine as intelligent as human for recognizing patterns. Pattern recognition is an active research and an importanttrait of ‘artificial intelligence’. This review paper introduces pattern recognition, its fundamental definitions, and provides understanding of related research work. This paper presents different types of algorithms, their...

  11. 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.

  12. Myopathy with antibodies to the signal recognition particle: report of 8 cases%抗信号识别颗粒抗体肌病八例临床分析

    Institute of Scientific and Technical Information of China (English)

    王璐; 张巍; 郝洪军; 洪道俊; 高枫; 袁云

    2012-01-01

    目的 总结抗信号识别颗粒抗体肌病患者的临床和骨骼肌病理改变特点.方法 选择8例患者采取免疫印迹法测定血清肌炎抗体谱并进行肌肉活检,肌肉标本进行组织学、酶组织化学和免疫组织化学染色.免疫组织化学染色的第一抗体为鼠抗人CD8、CD20、CD68单克隆抗体,分别标记T细胞、B细胞和巨噬细胞,主要组织相容性复合体(MHC)-Ⅰ单克隆抗体标记肌纤维膜,CD31单克隆抗体标记毛细血管内皮细胞.结果 8例患者血清抗信号识别颗粒抗体均为强阳性,其中3例伴随Ro-52抗体阳性.8例患者骨骼肌出现肌纤维坏死、再生以及巨噬细胞浸润,2例患者伴随肌纤维肥大和间质增生,2例伴随少数T细胞浸润.存在部分MHC-Ⅰ阳性肌纤维,毛细血管密度正常.结论 抗信号识别颗粒抗体肌病以缓慢发病的肢体无力为主要表现,可伴肺部病变.肌纤维坏死、再生为其主要病理改变,可以类似肌营养不良改变.%Objective We report the clinical and pathological features of 8 Chinese myopathy patients with antibodies to the signal recognition particle (SRP).Methods Serum myositis antibody profiles were tested with immunoblotting.Muscle biopsies were performed for histological,enzyme histochemical and immunohistochemical stainings.The first antibody in the immunohistochemical staining was mouse anti-human monoclonal antibodies including CD8,CD20,CD68,MHC- Ⅰ and CD31.Results Eight cases showed stark positive of anti SRP antibody,3 of them with positive anti Ro-52 antibody.The muscle biopsies showed necrotic and regenerative muscle fibers associated with infiltration of macrophage,but scattered T lymphocytes in 2 patients.Two of them presented with fiber hypertrophy and proliferation of connective tissue.There were some fibers with positive MHC-Ⅰ expression.Capillaries were almost normal.Conclusion The muscle weakness of myopathy with antibodies to SRP presents as a chronic

  13. 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,

  14. Pseudomonas evades immune recognition of flagellin in both mammals and plants

    NARCIS (Netherlands)

    Bardoel, B.W.; Ent, S. van der; Pel, M.J.C.; Tommassen, J.; Pieterse, C.M.J.; Kessel, K.P.M. van; Strijp, J.A.G. van

    2011-01-01

    The building blocks of bacterial flagella, flagellin monomers, are potent stimulators of host innate immune systems. Recognition of flagellin monomers occurs by flagellin-specific pattern-recognition receptors, such as Toll-like receptor 5 (TLR5) in mammals and flagellin-sensitive 2 (FLS2) in plants

  15. Embedded Face Detection and Recognition

    Directory of Open Access Journals (Sweden)

    Göksel Günlü

    2012-10-01

    Full Text Available The need to increase security in open or public spaces has in turn given rise to the requirement to monitor these spaces and analyse those images on‐site and on‐time. At this point, the use of smart cameras ‐ of which the popularity has been increasing ‐ is one step ahead. With sensors and Digital Signal Processors (DSPs, smart cameras generate ad hoc results by analysing the numeric images transmitted from the sensor by means of a variety of image‐processing algorithms. Since the images are not transmitted to a distance processing unit but rather are processed inside the camera, it does not necessitate high‐ bandwidth networks or high processor powered systems; it can instantaneously decide on the required access. Nonetheless, on account of restricted memory, processing power and overall power, image processing algorithms need to be developed and optimized for embedded processors. Among these algorithms, one of the most important is for face detection and recognition. A number of face detection and recognition methods have been proposed recently and many of these methods have been tested on general‐purpose processors. In smart cameras ‐ which are real‐life applications of such methods ‐ the widest use is on DSPs. In the present study, the Viola‐Jones face detection method ‐ which was reported to run faster on PCs ‐ was optimized for DSPs; the face recognition method was combined with the developed sub‐region and mask‐based DCT (Discrete Cosine Transform. As the employed DSP is a fixed‐point processor, the processes were performed with integers insofar as it was possible. To enable face recognition, the image was divided into sub‐ regions and from each sub‐region the robust coefficients against disruptive elements ‐ like face expression, illumination, etc. ‐ were selected as the features. The discrimination of the selected features was enhanced via LDA (Linear Discriminant Analysis and then employed for

  16. Crystallographic analysis of Neisseria meningitidis PorB extracellular loops potentially implicated in TLR2 recognition.

    Science.gov (United States)

    Kattner, Christof; Toussi, Deana N; Zaucha, Jan; Wetzler, Lee M; Rüppel, Nadine; Zachariae, Ulrich; Massari, Paola; Tanabe, Mikio

    2014-03-01

    Among all Neisseriae species, Neisseria meningitidis and Neisseria gonorrhoeae are the only human pathogens, causative agents of bacterial meningitis and gonorrhoea, respectively. PorB, a pan-Neisseriae trimeric porin that mediates diffusive transport of essential molecules across the bacterial outer membrane, is also known to activate host innate immunity via Toll-like receptor 2 (TLR2)-mediated signaling. The molecular mechanism of PorB binding to TLR2 is not known, but it has been hypothesized that electrostatic interactions contribute to ligand/receptor binding. Strain-specific sequence variability in the surface-exposed loops of PorB which are potentially implicated in TLR2 binding, may explain the difference in TLR2-mediated cell activation in vitro by PorB homologs from the commensal Neisseriae lactamica and the pathogen N. meningitidis. Here, we report a comparative structural analysis of PorB from N. meningitidis serogroup B strain 8765 (63% sequence homology with PorB from N. meningitidis serogroup W135) and a mutant in which amino acid substitutions in the extracellular loop 7 lead to significantly reduced TLR2-dependent activity in vitro. We observe that this mutation both alters the loop conformation and causes dramatic changes of electrostatic surface charge, both of which may affect TLR2 recognition and signaling. PMID:24361688

  17. Bacterial communication and group behavior

    OpenAIRE

    Greenberg, E. Peter

    2003-01-01

    The existence of species-specific and interspecies bacterial cell-cell communication and group organization was only recently accepted. Researchers are now realizing that the ability of these microbial teams to communicate and form structures, known as biofilms, at key times during the establishment of infection significantly increases their ability to evade both host defenses and antibiotics. This Perspective series discusses the known signaling mechanisms, the roles they play in both chroni...

  18. Multimodal recognition of emotions

    NARCIS (Netherlands)

    Datcu, D.

    2009-01-01

    This thesis proposes algorithms and techniques to be used for automatic recognition of six prototypic emotion categories by computer programs, based on the recognition of facial expressions and emotion patterns in voice. Considering the applicability in real-life conditions, the research is carried

  19. Paradigms in object recognition

    International Nuclear Information System (INIS)

    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)

  20. 改进的禁忌搜索算法在肌电信号情感识别中的应用%Application of improved tabu search algorithm in affective recognition from EMG signal

    Institute of Scientific and Technical Information of China (English)

    邱红; 刘光远; 赖祥伟

    2012-01-01

    针对基于肌电(EMG)信号的情感识别问题,提出了一种新颖的特征选择方法.该方法用相关性分析对原始特征降维,再利用改进的禁忌搜索算法结合Fisher分类器,对高兴、厌恶、悲伤、惊奇、愤怒和恐惧6种肌电信号的情感进行特征选择.实验结果表明,该方法能以较少的特征获得较高的识别率,得到了有利于情感识别系统建立的有效特征子集.%To solve electromyography (EMG) -based affective recognition problem effectively, a novel feature selection method is proposed. First, correlation analysis is used to reduce the dimension of original feature subset Then improved tabu search al gorithm combined with Fisher classifier is adopted to find six electromyography (EMG) emotions (joy, disgust, grief, surprise, anger and fear) feature selection. The experimental results show that the method can obtain relatively high recognition rates with fewer features, and effective feature subsets beneficial to the establishment of affective recognition system are obtained.

  1. Caspase recruitment domain-containing protein 9 signaling in innate immunity and inflammation.

    Science.gov (United States)

    Roth, Susanne; Ruland, Jürgen

    2013-06-01

    Caspase recruitment domain-containing protein (Card)9 is a nonredundant adapter protein that functions in the innate immune system in the assembly of multifunctional signaling complexes. Together with B cell lymphoma (Bcl)10 and the paracaspase, mucosa-associated lymphoid tissue lymphoma translocation protein (Malt)1, Card9 links spleen-tyrosine kinase (Syk)-coupled C-type lectin receptors to inflammatory responses. Card9 signaling also responds to intracellular danger sensors, such as retinoic acid-inducible gene 1 (RIG-I)-like receptors (RLRs) and nucleotide-oligomerization domain (Nod)2. Card9 complexes are engaged upon fungal, bacterial, or viral recognition, and they are essential for host protection. Moreover, Card9 polymorphisms are commonly associated with human inflammatory diseases. Here, we discuss the molecular regulation and the physiological functions of Card9 in host defense and immune homeostasis, and provide a framework for the therapeutic targeting of Card9 signaling in immune-mediated diseases. PMID:23523010

  2. Bacterial gasotransmitters: an innate defense against antibiotics.

    Science.gov (United States)

    Luhachack, Lyly; Nudler, Evgeny

    2014-10-01

    In recent decades, there has been growing interest in the field of gasotransmitters, endogenous gaseous signaling molecules (NO, H2S, and CO), as regulators of a multitude of biochemical pathways and physiological processes. Most of the concerted effort has been on eukaryotic gasotransmitters until the subsequent discovery of bacterial counterparts. While the fundamental aspects of bacterial gasotransmitters remain undefined and necessitate further research, we will discuss a known specific role they play in defense against antibiotics. Considering the current dilemma of multidrug-resistant bacteria we consider it particularly prudent to exploring novel targets and approaches, of which the bacterial gasotransmitters, nitric oxide and hydrogen sulfide represent.

  3. The host type Ⅰ interferon response to viral and bacterial infections

    Institute of Scientific and Technical Information of China (English)

    Andrea K. PERRY; Gang CHEN; Dahai ZHENG; Hong TANG; Genhong CHENG

    2005-01-01

    Type Ⅰ interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type Ⅰ IFNs are produced following viral infections, but until recently, the mechanisms of viral recognition leading to IFN production were largely unknown. Toll like receptors (TLRs) have emerged as key transducers of type Ⅰ IFN during viral infections by recognizing various viral components. Furthermore, much progress has been made in defining the signaling pathways downstream of TLRs for type Ⅰ IFN production. TLR7 and TLR9 have become apparent as universally important in inducing type Ⅰ IFN during infection with most viruses, particularly by plasmacytoid dendritic cells. New intracellular viral pattern recognition receptors leading to type Ⅰ IFN production have been identified. Many bacteria can also induce the up-regulation of these cytokines. Interestingly, recent studies have found a detrimental effect on host cells if type Ⅰ IFN is produced during infection with the intracellular gram-positive bacterial pathogen, Listeria monocytogenes. This review will discuss the recent advances made in defining the signaling pathways leading to type Ⅰ IFN production.

  4. PCA facial expression recognition

    Science.gov (United States)

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

    2013-12-01

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

  5. Handbook of Face Recognition

    CERN Document Server

    Li, Stan Z

    2011-01-01

    This highly anticipated new edition provides a comprehensive account of face recognition research and technology, spanning the full range of topics needed for designing operational face recognition systems. After a thorough introductory chapter, each of the following chapters focus on a specific topic, reviewing background information, up-to-date techniques, and recent results, as well as offering challenges and future directions. Features: fully updated, revised and expanded, covering the entire spectrum of concepts, methods, and algorithms for automated face detection and recognition systems

  6. Mobile intention recognition

    CERN Document Server

    Kiefer, Peter

    2011-01-01

    Mobile Intention Recognition addresses problems of practical relevance for mobile system engineers: how can we make mobile assistance systems more intelligent? How can we model and recognize patterns of human behavior which span more than a limited spatial context? This text provides an overview on plan and intention recognition, ranging from the late 1970s to very recent approaches. This overview is unique as it discusses approaches with respect to the specificities of mobile intention recognition. This book covers problems from research on mobile assistance systems using methods from artific

  7. Dimensional emotion recognition in whispered speech signal based on cognitive performance evaluation%基于认知评估的多维耳语音情感识别

    Institute of Scientific and Technical Information of China (English)

    吴晨健; 黄程韦; 陈虹

    2015-01-01

    研究了基于认知评估原理的多维耳语音情感识别。首先,比较了耳语音情感数据库和数据采集方法,研究了耳语音情感表达的特点,特别是基本情感的表达特点。其次,分析了耳语音的情感特征,并通过近年来的文献总结相关阶特征在效价维和唤醒维上的特征。研究了效价维和唤醒维在区分耳语音情感中的作用。最后,研究情感识别算法和应用耳语音情感识别的高斯混合模型。认知能力的评估也融入到情感识别过程中,从而对耳语音情感识别的结果进行纠错。基于认知分数,可以提高情感识别的结果。实验结果表明,耳语音信号中共振峰特征与唤醒维度不显著相关,而短期能量特征与情感变化在唤醒维度相关。结合认知分数可以提高语音情感识别的结果。%The cognitive performance-based dimensional emotion recognition in whispered speech is studied.First,the whispered speech emotion databases and data collection methods are compared, and the character of emotion expression in whispered speech is studied,especially the basic types of emotions.Secondly,the emotion features for whispered speech is analyzed,and by reviewing the latest references,the related valence features and the arousal features are provided. The effectiveness of valence and arousal features in whispered speech emotion classification is studied.Finally,the Gaussian mixture model is studied and applied to whispered speech emotion recognition. The cognitive performance is also considered in emotion recognition so that the recognition errors of whispered speech emotion can be corrected.Based on the cognitive scores,the emotion recognition results can be improved.The results show that the formant features are not significantly related to arousal dimension,while the short-term energy features are related to the emotion changes in arousal dimension.Using the cognitive scores,the recognition

  8. Atypical sensors for direct and rapid neuronal detection of bacterial pathogens.

    Science.gov (United States)

    Lim, Ji Yeon; Choi, Seung-In; Choi, Geunyeol; Hwang, Sun Wook

    2016-03-09

    Bacterial infection can threaten the normal biological functions of a host, often leading to a disease. Hosts have developed complex immune systems to cope with the danger. Preceding the elimination of pathogens, selective recognition of the non-self invaders is necessary. At the forefront of the body's defenses are the innate immune cells, which are equipped with particular sensor molecules that can detect common exterior patterns of invading pathogens and their secreting toxins as well as with phagocytic machinery. Inflammatory mediators and cytokines released from these innate immune cells and infected tissues can boost the inflammatory cascade and further recruit adaptive immune cells to maximize the elimination and resolution. The nervous system also seems to interact with this process, mostly known to be affected by the inflammatory mediators through the binding of neuronal receptors, consequently activating neural circuits that tune the local and systemic inflammatory states. Recent research has suggested new contact points: direct interactions of sensory neurons with pathogens. Latest findings demonstrated that the sensory neurons not only share pattern recognition mechanisms with innate immune cells, but also utilize endogenous and exogenous electrogenic components for bacterial pathogen detection, by which the electrical firing prompts faster information flow than what could be achieved when the immune system is solely involved. As a result, rapid pain generation and active accommodation of the immune status occur. Here we introduced the sensory neuron-specific detector molecules for directly responding to bacterial pathogens and their signaling mechanisms. We also discussed extended issues that need to be explored in the future.

  9. Robust Speech Recognition Using a Harmonic Model

    Institute of Scientific and Technical Information of China (English)

    许超; 曹志刚

    2004-01-01

    Automatic speech recognition under conditions of a noisy environment remains a challenging problem. Traditionally, methods focused on noise structure, such as spectral subtraction, have been employed to address this problem, and thus the performance of such methods depends on the accuracy in noise estimation. In this paper, an alternative method, using a harmonic-based spectral reconstruction algorithm, is proposed for the enhancement of robust automatic speech recognition. Neither noise estimation nor noise-model training are required in the proposed approach. A spectral subtraction integrated autocorrelation function is proposed to determine the pitch for the harmonic model. Recognition results show that the harmonic-based spectral reconstruction approach outperforms spectral subtraction in the middle- and low-signal noise ratio (SNR) ranges. The advantage of the proposed method is more manifest for non-stationary noise, as the algorithm does not require an assumption of stationary noise.

  10. Auditory—Spectrum Quantization Based Speech Recognition

    Institute of Scientific and Technical Information of China (English)

    WuYuanqing; HaoJie; 等

    1997-01-01

    Based on the analysis of the physiological and psychological characteristics of human auditory system[1],we can classify human auditory process into two hearing modes:active one and passive one.A novel approach of robust speech recognition,Auditory-spectrum Quantization Based Speech Recognition(AQBSR),is proposed.In this method,we intend to simulate human active hearing mode and locate the effective areas of speech signals in temporal domain and in frequency domain.Adaptive filter banks are used in place of fixed-band filters to extract feature parameters.The effective speech components and their corresponding frequency areas of each word in the vocabulary can be found out during training.In recognition stage,comparison between the unknown sound and the current template is maintained only in the effective areas of the template word.The control experiments show that the AQ BSR method is more robust than traditional systems.

  11. Robust Facial Expression Recognition via Compressive Sensing

    Directory of Open Access Journals (Sweden)

    Shiqing Zhang

    2012-03-01

    Full Text Available Recently, compressive sensing (CS has attracted increasing attention in the areas of signal processing, computer vision and pattern recognition. In this paper, a new method based on the CS theory is presented for robust facial expression recognition. The CS theory is used to construct a sparse representation classifier (SRC. The effectiveness and robustness of the SRC method is investigated on clean and occluded facial expression images. Three typical facial features, i.e., the raw pixels, Gabor wavelets representation and local binary patterns (LBP, are extracted to evaluate the performance of the SRC method. Compared with the nearest neighbor (NN, linear support vector machines (SVM and the nearest subspace (NS, experimental results on the popular Cohn-Kanade facial expression database demonstrate that the SRC method obtains better performance and stronger robustness to corruption and occlusion on robust facial expression recognition tasks.

  12. Analysis of Human Electrocardiogram for Biometric Recognition

    Directory of Open Access Journals (Sweden)

    Konstantinos N. Plataniotis

    2007-11-01

    Full Text Available Security concerns increase as the technology for falsification advances. There are strong evidences that a difficult to falsify biometric trait, the human heartbeat, can be used for identity recognition. Existing solutions for biometric recognition from electrocardiogram (ECG signals are based on temporal and amplitude distances between detected fiducial points. Such methods rely heavily on the accuracy of fiducial detection, which is still an open problem due to the difficulty in exact localization of wave boundaries. This paper presents a systematic analysis for human identification from ECG data. A fiducial-detection-based framework that incorporates analytic and appearance attributes is first introduced. The appearance-based approach needs detection of one fiducial point only. Further, to completely relax the detection of fiducial points, a new approach based on autocorrelation (AC in conjunction with discrete cosine transform (DCT is proposed. Experimentation demonstrates that the AC/DCT method produces comparable recognition accuracy with the fiducial-detection-based approach.

  13. Analysis of Human Electrocardiogram for Biometric Recognition

    Science.gov (United States)

    Wang, Yongjin; Agrafioti, Foteini; Hatzinakos, Dimitrios; Plataniotis, Konstantinos N.

    2007-12-01

    Security concerns increase as the technology for falsification advances. There are strong evidences that a difficult to falsify biometric trait, the human heartbeat, can be used for identity recognition. Existing solutions for biometric recognition from electrocardiogram (ECG) signals are based on temporal and amplitude distances between detected fiducial points. Such methods rely heavily on the accuracy of fiducial detection, which is still an open problem due to the difficulty in exact localization of wave boundaries. This paper presents a systematic analysis for human identification from ECG data. A fiducial-detection-based framework that incorporates analytic and appearance attributes is first introduced. The appearance-based approach needs detection of one fiducial point only. Further, to completely relax the detection of fiducial points, a new approach based on autocorrelation (AC) in conjunction with discrete cosine transform (DCT) is proposed. Experimentation demonstrates that the AC/DCT method produces comparable recognition accuracy with the fiducial-detection-based approach.

  14. Work and Recognition

    DEFF Research Database (Denmark)

    Willig, Rasmus

    2004-01-01

    individual and collective identity formation and has led to an increase in social pathological illnesses such as stress and depression. By juxtaposing these analyses with Honneth’s theory on recognition, we conclude that the contemporary logic of work is unable to provide adequate forms of recognition......The article deals with the relationship between work and recognition, taking Axel Honneth’s social-philosophical theory of the struggle for recognition as its point of departure. In order to give sociological substance to Honneth’s theory, we turn to three contemporary social theorists - Jean......-Pierre Le Goff, Christophe Dejours and Emmanuel Renault. In spite of many differences, their work is united by a critical description of the logic of work and its consequences for individual individuation. These theorists agree that the growth of autonomy, flexibility and mobility has destabilised...

  15. Human Emotion Recognition System

    Directory of Open Access Journals (Sweden)

    Dilbag Singh

    2012-08-01

    Full Text Available This paper discusses the application of feature extraction of facial expressions with combination of neural network for the recognition of different facial emotions (happy, sad, angry, fear, surprised, neutral etc... Humans are capable of producing thousands of facial actions during communication that vary in complexity, intensity, and meaning. This paper analyses the limitations with existing system Emotion recognition using brain activity. In this paper by using an existing simulator I have achieved 97 percent accurate results and it is easy and simplest way than Emotion recognition using brain activity system. Purposed system depends upon human face as we know face also reflects the human brain activities or emotions. In this paper neural network has been used for better results. In the end of paper comparisons of existing Human Emotion Recognition System has been made with new one.

  16. Prosody recognition in adults with high-functioning autism spectrum disorders: from psychoacoustics to cognition.

    Science.gov (United States)

    Globerson, Eitan; Amir, Noam; Kishon-Rabin, Liat; Golan, Ofer

    2015-04-01

    Prosody is an important tool of human communication, carrying both affective and pragmatic messages in speech. Prosody recognition relies on processing of acoustic cues, such as the fundamental frequency of the voice signal, and their interpretation according to acquired socioemotional scripts. Individuals with autism spectrum disorders (ASD) show deficiencies in affective prosody recognition. These deficiencies have been mostly associated with general difficulties in emotion recognition. The current study explored an additional association between affective prosody recognition in ASD and auditory perceptual abilities. Twenty high-functioning male adults with ASD and 32 typically developing male adults, matched on age and verbal abilities undertook a battery of auditory tasks. These included affective and pragmatic prosody recognition tasks, two psychoacoustic tasks (pitch direction recognition and pitch discrimination), and a facial emotion recognition task, representing nonvocal emotion recognition. Compared with controls, the ASD group demonstrated poorer performance on both vocal and facial emotion recognition, but not on pragmatic prosody recognition or on any of the psychoacoustic tasks. Both groups showed strong associations between psychoacoustic abilities and prosody recognition, both affective and pragmatic, although these were more pronounced in the ASD group. Facial emotion recognition predicted vocal emotion recognition in the ASD group only. These findings suggest that auditory perceptual abilities, alongside general emotion recognition abilities, play a significant role in affective prosody recognition in ASD.

  17. Automatic Licenses Plate Recognition

    OpenAIRE

    Ronak P Patel; Narendra M Patel; Keyur Brahmbhatt

    2013-01-01

    This paper describes the Smart Vehicle Screening System, which can be installed into a tollboothfor automated recognition of vehicle license plate information using a photograph of a vehicle. An automatedsystem could then be implemented to control the payment of fees, parking areas, highways, bridges ortunnels, etc. This paper contains new algorithm for recognition number plate using Morphological operation,Thresholding operation, Edge detection, Bounding box analysis for number plate extract...

  18. Human Emotion Recognition System

    OpenAIRE

    Dilbag Singh

    2012-01-01

    This paper discusses the application of feature extraction of facial expressions with combination of neural network for the recognition of different facial emotions (happy, sad, angry, fear, surprised, neutral etc..). Humans are capable of producing thousands of facial actions during communication that vary in complexity, intensity, and meaning. This paper analyses the limitations with existing system Emotion recognition using brain activity. In this paper by using an existing simulator I hav...

  19. Fingerprint Recognition System

    OpenAIRE

    Bhawna Negi; Varun Sharma

    2012-01-01

    The popular Biometric used to authenticate a person is Fingerprint which is unique and permanent throughout a person’s life. A minutia matching is widely used for fingerprint recognition and can be classified as ridge ending and ridge bifurcation. In this paper we projected Fingerprint Recognition using Minutia Score Matching method (FRMSM). For Fingerprint thinning, the Block Filter is used, which scans the image at the boundary to preserves the quality of the image and extract the minutiae ...

  20. The Recognition Of Fatigue

    DEFF Research Database (Denmark)

    Elsass, Peter; Jensen, Bodil; Mørup, Rikke;

    2007-01-01

    Elsass P., Jensen B., Morup R., Thogersen M.H. (2007). The Recognition Of Fatigue: A qualitative study of life-stories from rehabilitation clients. International Journal of Psychosocial Rehabilitation. 11 (2), 75-87......Elsass P., Jensen B., Morup R., Thogersen M.H. (2007). The Recognition Of Fatigue: A qualitative study of life-stories from rehabilitation clients. International Journal of Psychosocial Rehabilitation. 11 (2), 75-87...

  1. Why recognition is rational

    Directory of Open Access Journals (Sweden)

    Clintin P. Davis-Stober

    2010-07-01

    Full Text Available The Recognition Heuristic (Gigerenzer and Goldstein, 1996; Goldstein and Gigerenzer, 2002 makes the counter-intuitive prediction that a decision maker utilizing less information may do as well as, or outperform, an idealized decision maker utilizing more information. We lay a theoretical foundation for the use of single-variable heuristics such as the Recognition Heuristic as an optimal decision strategy within a linear modeling framework. We identify conditions under which over-weighting a single predictor is a mini-max strategy among a class of a priori chosen weights based on decision heuristics with respect to a measure of statistical lack of fit we call ``risk''. These strategies, in turn, outperform standard multiple regression as long as the amount of data available is limited. We also show that, under related conditions, weighting only one variable and ignoring all others produces the same risk as ignoring the single variable and weighting all others. This approach has the advantage of generalizing beyond the original environment of the Recognition Heuristic to situations with more than two choice options, binary or continuous representations of recognition, and to other single variable heuristics. We analyze the structure of data used in some prior recognition tasks and find that it matches the sufficient conditions for optimality in our results. Rather than being a poor or adequate substitute for a compensatory model, the Recognition Heuristic closely approximates an optimal strategy when a decision maker has finite data about the world.

  2. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...

  3. Active acoustic signals recognition of two kinds of stored grain pests based on Fast ICA%基于Fast ICA算法的2种储粮害虫活动声信号识别

    Institute of Scientific and Technical Information of China (English)

    张明真; 郭敏

    2012-01-01

    利用快速独立分量分析(fast independent component analysis,Fast ICA)算法,对混有高斯噪声的2种储粮害虫玉米象Sitophilus zeamais和赤拟谷盗Tribolium castaneum的活动声信号进行去噪,并使用Fast ICA算法识别和分离了2种储粮害虫爬行与翻身的4种活动声信号,证明了使用Fast ICA算法识别混合信号中每种害虫声信号的有效性和准确性.%Using fast independent component analysis algorithm, active acoustic signals mixed with gaussian noise of Sitophilus zeamais and Tribolium castaneum known as stored grain pests, were de-noised. Then Fast ICA algorithm were used to recognize and separate acoustic signals of four kinds of active acoustic signals, such as creeping and vibratory signals of Sitophilus zeamais and Tribolium castaneum. The results demonstrate the validity and accuracy to recognize each pest's acoustic signal from mixed signals by Fast ICA algorithm.

  4. Speech recognition: Acoustic, phonetic and lexical

    Science.gov (United States)

    Zue, V. W.

    1985-10-01

    Our long-term research goal is the development and implementation of speaker-independent continuous speech recognition systems. It is our conviction that proper utilization of speech-specific knowledge is essential for advanced speech recognition systems. With this in mind, we have continued to make progress on the acquisition of acoustic-phonetic and lexical knowledge. We have completed the development of a continuous digit recognition system. The system was constructed to investigate the utilization of acoustic phonetic knowledge in a speech recognition system. Some of the significant development of this study includes a soft-failure procedure for lexical access, and the discovery of a set of acoustic-phonetic features for verification. We have completed a study of the constraints provided by lexical stress on word recognition. We found that lexical stress information alone can, on the average, reduce the number of word candidates from a large dictionary by more than 80%. In conjunction with this study, we successfully developed a system that automatically determines the stress pattern of a word from the acoustic signal.

  5. Modeling Fan Effects on the Time Course of Associative Recognition

    Science.gov (United States)

    Schneider, Darryl W.; Anderson, John R.

    2012-01-01

    We investigated the time course of associative recognition using the response signal procedure, whereby a stimulus is presented and followed after a variable lag by a signal indicating that an immediate response is required. More specifically, we examined the effects of associative fan (the number of associations that an item has with other items…

  6. Protein hydrogels with engineered biomolecular recognition

    Science.gov (United States)

    Mi, Lixin

    Extracellular matrices (ECMs) are the hydrated macromolecular gels in which cells migrate and proliferate and organize into tissues in vivo . The development of artificial ECM with the required mechanical, physico-chemical, and biological properties has long been a challenge in the biomaterial research field. In this dissertation, a novel set of bioactive protein hydrogels has been synthesized and characterized at both molecular and materials levels. The self-recognized and self-assembled protein copolymers have the ability to provide engineered biofunctionality through the controlled arrangement of bioactive domains on the nanoscale. Genetic engineering methods have been employed to synthesize these protein copolymers. Plasmid DNA carrying genes to express both di- and tri-block proteins have been constructed using molecular cloning techniques. These genes were expressed in bacterial E. coli to ensure homogeneous protein length and anticipated structure. Three diblock protein sequences having a leucine zipper construct on one end and polyelectrolyte (AGAGAGPEG)10 on the other, have been studied by circular dichroism, size-exclusion chromatography, analytical ultracentrifugation, and static light scattering to characterize their secondary structure, structural stability, and oligomeric state. The results show that ABC diblock mixtures form very stable heterotrimer aggregates via self-recognition and self-assembly of the coiled coil end domains. Tri-block proteins with two leucine zipper motif ends flanking the polyelectrolyte random coil in the middle have been investigated by circular dichroism and fluorescence spectroscopy, and the hydrogels formed by self-assembly of these tri-blocks have been studied using transmission electronic microscopy and diffusing wave spectroscopy. The reversible gelation behavior is the result of heterotrimeric aggregation of helices to form the physical crosslinks in the gel, with the polyelectrolyte region center block retaining

  7. 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

  8. An analytical approach to photonic reservoir computing - a network of SOA's - for noisy speech recognition

    Science.gov (United States)

    Salehi, Mohammad Reza; Abiri, Ebrahim; Dehyadegari, Louiza

    2013-10-01

    This paper seeks to investigate an approach of photonic reservoir computing for optical speech recognition on an examination isolated digit recognition task. An analytical approach in photonic reservoir computing is further drawn on to decrease time consumption, compared to numerical methods; which is very important in processing large signals such as speech recognition. It is also observed that adjusting reservoir parameters along with a good nonlinear mapping of the input signal into the reservoir, analytical approach, would boost recognition accuracy performance. Perfect recognition accuracy (i.e. 100%) can be achieved for noiseless speech signals. For noisy signals with 0-10 db of signal to noise ratios, however, the accuracy ranges observed varied between 92% and 98%. In fact, photonic reservoir application demonstrated 9-18% improvement compared to classical reservoir networks with hyperbolic tangent nodes.

  9. Speech recognition from spectral dynamics

    Indian Academy of Sciences (India)

    Hynek Hermansky

    2011-10-01

    Information is carried in changes of a signal. The paper starts with revisiting Dudley’s concept of the carrier nature of speech. It points to its close connection to modulation spectra of speech and argues against short-term spectral envelopes as dominant carriers of the linguistic information in speech. The history of spectral representations of speech is briefly discussed. Some of the history of gradual infusion of the modulation spectrum concept into Automatic recognition of speech (ASR) comes next, pointing to the relationship of modulation spectrum processing to wellaccepted ASR techniques such as dynamic speech features or RelAtive SpecTrAl (RASTA) filtering. Next, the frequency domain perceptual linear prediction technique for deriving autoregressive models of temporal trajectories of spectral power in individual frequency bands is reviewed. Finally, posterior-based features, which allow for straightforward application of modulation frequency domain information, are described. The paper is tutorial in nature, aims at a historical global overview of attempts for using spectral dynamics in machine recognition of speech, and does not always provide enough detail of the described techniques. However, extensive references to earlier work are provided to compensate for the lack of detail in the paper.

  10. Collective Functionality through Bacterial Individuality

    Science.gov (United States)

    Ackermann, Martin

    According to the conventional view, the properties of an organism are a product of nature and nurture - of its genes and the environment it lives in. Recent experiments with unicellular organisms have challenged this view: several molecular mechanisms generate phenotypic variation independently of environmental signals, leading to variation in clonal groups. My presentation will focus on the causes and consequences of this microbial individuality. Using examples from bacterial genetic model systems, I will first discuss different molecular and cellular mechanisms that give rise to bacterial individuality. Then, I will discuss the consequences of individuality, and focus on how phenotypic variation in clonal populations of bacteria can promote interactions between individuals, lead to the division of labor, and allow clonal groups of bacteria to cope with environmental uncertainty. Variation between individuals thus provides clonal groups with collective functionality.

  11. Bimodal Emotion Recognition from Speech and Text

    Directory of Open Access Journals (Sweden)

    Weilin Ye

    2014-01-01

    Full Text Available This paper presents an approach to emotion recognition from speech signals and textual content. In the analysis of speech signals, thirty-seven acoustic features are extracted from the speech input. Two different classifiers Support Vector Machines (SVMs and BP neural network are adopted to classify the emotional states. In text analysis, we use the two-step classification method to recognize the emotional states. The final emotional state is determined based on the emotion outputs from the acoustic and textual analyses. In this paper we have two parallel classifiers for acoustic information and two serial classifiers for textual information, and a final decision is made by combing these classifiers in decision level fusion. Experimental results show that the emotion recognition accuracy of the integrated system is better than that of either of the two individual approaches.

  12. Acoustic Signal Processing

    Science.gov (United States)

    Hartmann, William M.; Candy, James V.

    Signal processing refers to the acquisition, storage, display, and generation of signals - also to the extraction of information from signals and the re-encoding of information. As such, signal processing in some form is an essential element in the practice of all aspects of acoustics. Signal processing algorithms enable acousticians to separate signals from noise, to perform automatic speech recognition, or to compress information for more efficient storage or transmission. Signal processing concepts are the building blocks used to construct models of speech and hearing. Now, in the 21st century, all signal processing is effectively digital signal processing. Widespread access to high-speed processing, massive memory, and inexpensive software make signal processing procedures of enormous sophistication and power available to anyone who wants to use them. Because advanced signal processing is now accessible to everybody, there is a need for primers that introduce basic mathematical concepts that underlie the digital algorithms. The present handbook chapter is intended to serve such a purpose.

  13. Xanthomonas campestris cell-cell signalling molecule DSF (diffusible signal factor) elicits innate immunity in plants and is suppressed by the exopolysaccharide xanthan.

    Science.gov (United States)

    Kakkar, Akanksha; Nizampatnam, Narasimha Rao; Kondreddy, Anil; Pradhan, Binod Bihari; Chatterjee, Subhadeep

    2015-11-01

    Several secreted and surface-associated conserved microbial molecules are recognized by the host to mount the defence response. One such evolutionarily well-conserved bacterial process is the production of cell-cell signalling molecules which regulate production of multiple virulence functions by a process known as quorum sensing. Here it is shown that a bacterial fatty acid cell-cell signalling molecule, DSF (diffusible signal factor), elicits innate immunity in plants. The DSF family of signalling molecules are highly conserved among many phytopathogenic bacteria belonging to the genus Xanthomonas as well as in opportunistic animal pathogens. Using Arabidopsis, Nicotiana benthamiana, and rice as model systems, it is shown that DSF induces a hypersensitivity reaction (HR)-like response, programmed cell death, the accumulation of autofluorescent compounds, hydrogen peroxide production, and the expression of the PATHOGENESIS-RELATED1 (PR-1) gene. Furthermore, production of the DSF signalling molecule in Pseudomonas syringae, a non-DSF-producing plant pathogen, induces the innate immune response in the N. benthamiana host plant and also affects pathogen growth. By pre- and co-inoculation of DSF, it was demonstrated that the DSF-induced plant defence reduces disease severity and pathogen growth in the host plant. In this study, it was further demonstrated that wild-type Xanthomonas campestris suppresses the DSF-induced innate immunity by secreting xanthan, the main component of extracellular polysaccharide. The results indicate that plants have evolved to recognize a widely conserved bacterial communication system and may have played a role in the co-evolution of host recognition of the pathogen and the communication machinery. PMID:26248667

  14. Speech Recognition in Natural Background Noise

    OpenAIRE

    Julien Meyer; Laure Dentel; Fanny Meunier

    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 listene...

  15. Phonetic Alphabet for Speech Recognition of Czech

    OpenAIRE

    J. Uhlir; Psutka, J.; J. Nouza

    1997-01-01

    In the paper we introduce and discuss an alphabet that has been proposed for phonemicly oriented automatic speech recognition. The alphabet, denoted as a PAC (Phonetic Alphabet for Czech) consists of 48 basic symbols that allow for distinguishing all major events occurring in spoken Czech language. The symbols can be used both for phonetic transcription of Czech texts as well as for labeling recorded speech signals. From practical reasons, the alphabet occurs in two versions; one utilizes Cze...

  16. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    that imposes selection pressure for resistant bacteria. New approaches are urgently needed. Targeting bacterial virulence functions directly is an attractive alternative. An obvious target is bacterial adhesion. Bacterial adhesion to surfaces is the first step in colonization, invasion, and biofilm formation....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will become...

  17. Bioinformatic Comparison of Bacterial Secretomes

    Institute of Scientific and Technical Information of China (English)

    Catharine Song; Aseem Kumar; Mazen Saleh

    2009-01-01

    The rapid increasing number of completed bacterial genomes provides a good op-portunity to compare their proteomes. This study was undertaken to specifically compare and contrast their secretomes-the fraction of the proteome with pre-dicted N-terminal signal sequences, both type Ⅰ and type Ⅱ. A total of 176 theoreti-cal bacterial proteomes were examined using the ExProt program. Compared with the Gram-positives, the Gram-negative bacteria were found, on average, to con-tain a larger number of potential Sec-dependent sequences. In the Gram-negative bacteria but not in the others, there was a positive correlation between proteome size and secretome size, while there was no correlation between secretome size and pathogenicity. Within the Gram-negative bacteria, intracellular pathogens were found to have the smallest secretomes. However, the secretomes of certain bacte-ria did not fit into the observed pattern. Specifically, the secretome of Borrelia burgdoferi has an unusually large number of putative lipoproteins, and the signal peptides of mycoplasmas show closer sequence similarity to those of the Gram-negative bacteria. Our analysis also suggests that even for a theoretical minimal genome of 300 open reading frames, a fraction of this gene pool (up to a maximum of 20%) may code for proteins with Sec-dependent signal sequences.

  18. Speech Recognition Using HMM with MFCC-An Analysis Using Frequency Specral Decomposion Technique

    Directory of Open Access Journals (Sweden)

    Ibrahim Patel

    2010-12-01

    Full Text Available This paper presents an approach to the recognition of speech signal using frequency spectral information with Mel frequency for the improvement of speech feature representation in a HMM based recognition approach. A frequency spectral information is incorporated to the conventional Mel spectrum base speech recognition approach. The Mel frequency approach exploits the frequency observation for speech signal in a given resolution which results in resolution feature overlapping resulting in recognition limit. Resolution decomposition with separating frequency is mapping approach for a HMM based speech recognition system. The Simulation results show an improvement in the quality metrics of speech recognition with respect to computational time, learning accuracy for a speech recognition system.

  19. Human motion recognition based on features and models selected HMM

    Science.gov (United States)

    Lu, Haixiang; Zhou, Hongjun

    2015-03-01

    This paper research on the motion recognition based on HMM with Kinect. Kinect provides skeletal data consist of 3D body joints with its lower price and convenience. In this work, several methods are used to determine the optimal subset of features among Cartesian coordinates, distance to hip center, velocity, angle and angular velocity, in order to improve the recognition rate. K-means is used for vector quantization and HMM is used as recognition method. HMM is an effective signal processing method which contains time calibration, provides a learning mechanism and recognition ability. Cluster numbers of K-means, structure and state numbers of HMM are optimized as well. The proposed methods are applied to the MSR Action3D dataset. Results show that the proposed methods obtain better recognition accuracy than the state of the art methods.

  20. Two Redundant Receptor-Like Cytoplasmic Kinases Function Downstream of Pattern Recognition Receptors to Regulate Activation of SA Biosynthesis.

    Science.gov (United States)

    Kong, Qing; Sun, Tongjun; Qu, Na; Ma, Junling; Li, Meng; Cheng, Yu-Ti; Zhang, Qian; Wu, Di; Zhang, Zhibin; Zhang, Yuelin

    2016-06-01

    Salicylic acid (SA) serves as a critical signaling molecule in plant defense. Two transcription factors, SARD1 and CBP60g, control SA biosynthesis through regulating pathogen-induced expression of Isochorismate Synthase1, which encodes a key enzyme for SA biosynthesis. Here, we report that Pattern-Triggered Immunity Compromised Receptor-like Cytoplasmic Kinase1 (PCRK1) and PCRK2 function as key regulators of SA biosynthesis. In the pcrk1 pcrk2 double mutant, pathogen-induced expression of SARD1, CBP60g, and ICS1 is greatly reduced. The pcrk1 pcrk2 double mutant, but neither of the single mutants, exhibits reduced accumulation of SA and enhanced disease susceptibility to bacterial pathogens. Both PCRK1 and PCRK2 interact with the pattern recognition receptor FLS2, and treatment with pathogen-associated molecular patterns leads to rapid phosphorylation of PCRK2. Our data suggest that PCRK1 and PCRK2 function downstream of pattern recognition receptor in a signal relay leading to the activation of SA biosynthesis. PMID:27208222

  1. Time-expanded speech and speech recognition in older adults.

    Science.gov (United States)

    Vaughan, Nancy E; Furukawa, Izumi; Balasingam, Nirmala; Mortz, Margaret; Fausti, Stephen A

    2002-01-01

    Speech understanding deficits are common in older adults. In addition to hearing sensitivity, changes in certain cognitive functions may affect speech recognition. One such change that may impact the ability to follow a rapidly changing speech signal is processing speed. When speakers slow the rate of their speech naturally in order to speak clearly, speech recognition is improved. The acoustic characteristics of naturally slowed speech are of interest in developing time-expansion algorithms to improve speech recognition for older listeners. In this study, we tested younger normally hearing, older normally hearing, and older hearing-impaired listeners on time-expanded speech using increased duration and increased intensity of unvoiced consonants. Although all groups performed best on unprocessed speech, performance with processed speech was better with the consonant gain feature without time expansion in the noise condition and better at the slowest time-expanded rate in the quiet condition. The effects of signal processing on speech recognition are discussed. PMID:17642020

  2. 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...

  3. Are Haar-like Rectangular Features for Biometric Recognition Reducible?

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.

    2013-01-01

    Biometric recognition is still a very difficult task in real-world scenarios wherein unforeseen changes in degradations factors like noise, occlusion, blurriness and illumination can drastically affect the extracted features from the biometric signals. Very recently Haar-like rectangular features...... which have usually been used for object detection were introduced for biometric recognition resulting in systems that are robust against most of the mentioned degradations [9]. The problem with these features is that one can define many different such features for a given biometric signal...... and it is not clear whether all of these features are required for the actual recognition or not. This is exactly what we are dealing with in this paper: How can an initial set of Haar-like rectangular features, that have been used for biometric recognition, be reduced to a set of most influential features...

  4. Arabidopsis EDS1 connects pathogen effector recognition to cell compartment-specific immune responses.

    Science.gov (United States)

    Heidrich, Katharina; Wirthmueller, Lennart; Tasset, Céline; Pouzet, Cécile; Deslandes, Laurent; Parker, Jane E

    2011-12-01

    Pathogen effectors are intercepted by plant intracellular nucleotide binding-leucine-rich repeat (NB-LRR) receptors. However, processes linking receptor activation to downstream defenses remain obscure. Nucleo-cytoplasmic basal resistance regulator EDS1 (ENHANCED DISEASE SUSCEPTIBILITY1) is indispensible for immunity mediated by TIR (Toll-interleukin-1 receptor)-NB-LRR receptors. We show that Arabidopsis EDS1 molecularly connects TIR-NB-LRR disease resistance protein RPS4 recognition of bacterial effector AvrRps4 to defense pathways. RPS4-EDS1 and AvrRps4-EDS1 complexes are detected inside nuclei of living tobacco cells after transient coexpression and in Arabidopsis soluble leaf extracts after resistance activation. Forced AvrRps4 localization to the host cytoplasm or nucleus reveals cell compartment-specific RPS4-EDS1 defense branches. Although nuclear processes restrict bacterial growth, programmed cell death and transcriptional resistance reinforcement require nucleo-cytoplasmic coordination. Thus, EDS1 behaves as an effector target and activated TIR-NB-LRR signal transducer for defenses across cell compartments.

  5. Finding Signals for Plant Promoters

    Institute of Scientific and Technical Information of China (English)

    Weimou Zheng

    2003-01-01

    The strongest signal of plant promoter is searched with the model of single motif with two types. It turns out that the dominant type is the TATA-box. The other type may be called TATA-less signal, and may be used in gene finders for promoter recognition. While the TATA signals are very close for the monocot and the dicot, their TATA-less signals are significantly different. A general and flexible multi-motif model is also proposed for promoter analysis based on dynamic programming. By extending the Gibbs sampler to the dynamic programming and introducing temperature, an efficient algorithm is developed for searching signals in plant promoters.

  6. Structures of pattern recognition receptors reveal molecular mechanisms of autoinhibition, ligand recognition and oligomerization.

    Science.gov (United States)

    Chuenchor, Watchalee; Jin, Tengchuan; Ravilious, Geoffrey; Xiao, T Sam

    2014-02-01

    Pattern recognition receptors (PRRs) are essential sentinels for pathogens or tissue damage and integral components of the innate immune system. Recent structural studies have provided unprecedented insights into the molecular mechanisms of ligand recognition and signal transduction by several PRR families at distinct subcellular compartments. Here we highlight some of the recent discoveries and summarize the common themes that are emerging from these exciting studies. Better mechanistic understanding of the structure and function of the PRRs will improve future prospects of therapeutic targeting of these important innate immune receptors.

  7. Microfluidic Approaches to Bacterial Biofilm Formation

    Directory of Open Access Journals (Sweden)

    Hee-Deung Park

    2012-08-01

    Full Text Available Bacterial biofilms—aggregations of bacterial cells and extracellular polymeric substrates (EPS—are an important subject of research in the fields of biology and medical science. Under aquatic conditions, bacterial cells form biofilms as a mechanism for improving survival and dispersion. In this review, we discuss bacterial biofilm development as a structurally and dynamically complex biological system and propose microfluidic approaches for the study of bacterial biofilms. Biofilms develop through a series of steps as bacteria interact with their environment. Gene expression and environmental conditions, including surface properties, hydrodynamic conditions, quorum sensing signals, and the characteristics of the medium, can have positive or negative influences on bacterial biofilm formation. The influences of each factor and the combined effects of multiple factors may be addressed using microfluidic approaches, which provide a promising means for controlling the hydrodynamic conditions, establishing stable chemical gradients, performing measurement in a high-throughput manner, providing real-time monitoring, and providing in vivo-like in vitro culture devices. An increased understanding of biofilms derived from microfluidic approaches may be relevant to improving our understanding of the contributions of determinants to bacterial biofilm development.

  8. Phylogeny of Toll-like receptor signaling: adapting the innate response.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Roach

    Full Text Available The Toll-like receptors represent a largely evolutionarily conserved pathogen recognition machinery responsible for recognition of bacterial, fungal, protozoan, and viral pathogen associated microbial patterns and initiation of inflammatory response. Structurally the Toll-like receptors are comprised of an extracellular leucine rich repeat domain and a cytoplasmic Toll/Interleukin 1 receptor domain. Recognition takes place in the extracellular domain where as the cytoplasmic domain triggers a complex signal network required to sustain appropriate immune response. Signal transduction is regulated by the recruitment of different intracellular adaptors. The Toll-like receptors can be grouped depending on the usage of the adaptor, MyD88, into MyD88-dependent and MyD88 independent subsets. Herein, we present a unique phylogenetic analysis of domain regions of these receptors and their cognate signaling adaptor molecules. Although previously unclear from the phylogeny of full length receptors, these analyses indicate a separate evolutionary origin for the MyD88-dependent and MyD88-independent signaling pathway and provide evidence of a common ancestor for the vertebrate and invertebrate orthologs of the adaptor molecule MyD88. Together these observations suggest a very ancient origin of the MyD88-dependent pathway Additionally we show that early duplications gave rise to several adaptor molecule families. In some cases there is also strong pattern of parallel duplication between adaptor molecules and their corresponding TLR. Our results further support the hypothesis that phylogeny of specific domains involved in signaling pathway can shed light on key processes that link innate to adaptive immune response.

  9. Improved Open-Microphone Speech Recognition

    Science.gov (United States)

    Abrash, Victor

    2002-01-01

    Many current and future NASA missions make extreme demands on mission personnel both in terms of work load and in performing under difficult environmental conditions. In situations where hands are impeded or needed for other tasks, eyes are busy attending to the environment, or tasks are sufficiently complex that ease of use of the interface becomes critical, spoken natural language dialog systems offer unique input and output modalities that can improve efficiency and safety. They also offer new capabilities that would not otherwise be available. For example, many NASA applications require astronauts to use computers in micro-gravity or while wearing space suits. Under these circumstances, command and control systems that allow users to issue commands or enter data in hands-and eyes-busy situations become critical. Speech recognition technology designed for current commercial applications limits the performance of the open-ended state-of-the-art dialog systems being developed at NASA. For example, today's recognition systems typically listen to user input only during short segments of the dialog, and user input outside of these short time windows is lost. Mistakes detecting the start and end times of user utterances can lead to mistakes in the recognition output, and the dialog system as a whole has no way to recover from this, or any other, recognition error. Systems also often require the user to signal when that user is going to speak, which is impractical in a hands-free environment, or only allow a system-initiated dialog requiring the user to speak immediately following a system prompt. In this project, SRI has developed software to enable speech recognition in a hands-free, open-microphone environment, eliminating the need for a push-to-talk button or other signaling mechanism. The software continuously captures a user's speech and makes it available to one or more recognizers. By constantly monitoring and storing the audio stream, it provides the spoken

  10. Probabilistic Open Set Recognition

    Science.gov (United States)

    Jain, Lalit Prithviraj

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

  11. Danger signals activating innate immunity in graft-versus-host disease.

    Science.gov (United States)

    Zeiser, Robert; Penack, Olaf; Holler, Ernst; Idzko, Marco

    2011-09-01

    Extensive cell death with consecutive release of danger signals can cause immune-mediated tissue destruction. The abundance of cell death is likely to determine the relevance of the danger signals as physiological mechanisms that counteract immune activation may be overruled. Such constellation is conceivable in chemo-/radiotherapy-induced tissue damage, reperfusion injury, trauma, and severe infection. Studies on graft-versus-host disease (GvHD) development have to consider the effects of chemo-/radiotherapy-related tissue damage leading to the release of exogenous and endogenous danger signals. Our previous work has demonstrated a role for adenosine-5'-triphosphate (ATP) as an endogenous danger signal in GvHD. Besides ATP, uric acid or soluble extracellular matrix components are functional danger signals that activate the NLRP3 inflammasome when released from dying cells or from extracellular matrix. In contrast to sterile inflammation, GvHD is more complex since bacterial components that leak through damaged intestinal barriers and the skin can activate pattern recognition receptors and directly contribute to GvHD pathogenesis. These exogenous danger signals transmit immune activation via toll-like receptors and NOD-like receptors of the innate immune system. This review covers both the impact of endogenous and exogenous danger signals activating innate immunity in GvHD.

  12. An Intersecting Cortical Model Based Framework for Human Face Recognition

    OpenAIRE

    Ahmed G. Mahgoub; Amira A. Ebeid; Hossam-El-Deen M. Abdel-Baky; El-Sayed A. El-Badawy

    2008-01-01

    This paper introduces a novel method for human face recognition based on a simplified approach for the Pulse Coupled Neural Network (PCNN) Algorithm. The face image is introduced to the Intersecting Cortical Model (ICM) to be iterated 200 times, and then the time signals for the faces are compared to make a decision. Experimental results for human face recognition confirm that the proposed method lends itself to higher classification accuracy relative to existing techniques.

  13. Joint speech and spearker recognition using neural networks

    OpenAIRE

    Xue, Xiaoguo

    2013-01-01

    Speech is the main communication method between human beings. Since the time of the invention of the computer people have been trying to let the computer understand natural speech. Speech recognition is a technology which has close connections with computer science, signal processing, voice linguistics and intelligent systems. It has been a ”hot” subject not only in the field of research but also as a practical application. Especially in real life, speaker and speech recognition have been use...

  14. An Intersecting Cortical Model Based Framework for Human Face Recognition

    Directory of Open Access Journals (Sweden)

    Ahmed G. Mahgoub

    2008-04-01

    Full Text Available This paper introduces a novel method for human face recognition based on a simplified approach for the Pulse Coupled Neural Network (PCNN Algorithm. The face image is introduced to the Intersecting Cortical Model (ICM to be iterated 200 times, and then the time signals for the faces are compared to make a decision. Experimental results for human face recognition confirm that the proposed method lends itself to higher classification accuracy relative to existing techniques.

  15. An integrated approach to emotion recognition for advanced emotional intelligence

    OpenAIRE

    Panagiotis D Bamidis; Frantzidis, Christos A.; Konstantinidis, Evdokimos I.; Luneski, Andrej; Lithari, Chrysa; Klados, Manousos A.; Bratsas, Charalambos; Papadelis, Christos; Pappas, Costas

    2009-01-01

    Emotion identification is beginning to be considered as an essential feature in human-computer interaction. However, most of the studies are mainly focused on facial expression classifications and speech recognition and not much attention has been paid until recently to physiological pattern recognition. In this paper, an integrative approach is proposed to emotional interaction by fusing multi-modal signals. Subjects are exposed to pictures selected from the International Affective Pic...

  16. Wi-Fi Gesture Recognition on Existing Devices

    OpenAIRE

    Nandakumar, Rajalakshmi; Kellogg, Bryce; Gollakota, Shyamnath

    2014-01-01

    This paper introduces the first wireless gesture recognition system that operates using existingWi-Fi signals and devices. To achieve this, we first identify limitations of existing wireless gesture recognition approaches that limit their applicability to Wi-Fi. We then introduce algorithms that can classify gestures using information that is readily available on Wi-Fi devices. We demonstrate the feasibility of our design using a prototype implementation on off-the-shelf Wi-Fi devices. Our re...

  17. Driver Recognition Using Gaussian Mixture Models and Decision Fusion Techniques

    OpenAIRE

    Benli, Kristin Surpuhi; Düzağaç, Remzi; Eskil, Mustafa Taner

    2008-01-01

    In this paper we present our research in driver recognition. The goal of this study is to investigate the performance of different classifier fusion techniques in a driver recognition scenario. We are using solely driving behavior signals such as break and accelerator pedal pressure, engine RPM, vehicle speed; steering wheel angle for identifying the driver identities. We modeled each driver using Gaussian Mixture Models, obtained posterior probabilities of identities and combined these score...

  18. FACIAL EMOTION RECOGNITION USING GABOR (HAPPY, SAD, ANGER, NEUTRAL MOOD)

    OpenAIRE

    Mohd Shamsh Alam

    2015-01-01

    The best way to communicate the emotions and intentions is facial expressions. This is powerful because as per the psychological research 55% of the total communicated message is the human facial expression. Therefore deriving an effective facial representation from the original face image is a vital step and very tough task in the field of computer science for successful facial expression recognition. Human facial recognition usually uses image processing, gesture signal ...

  19. Impaired recognition of social emotions following amygdala damage

    OpenAIRE

    Adolphs, Ralph; Baron-Cohen, Simon; Tranel, Daniel

    2002-01-01

    Lesion, functional imaging, and single-unit studies in human and nonhuman animals have demonstrated a role for the amygdala in processing stimuli with emotional and social significance. We investigated the recognition of a wide variety of facial expressions, including basic emotions (e.g., happiness, anger) and social emotions (e.g., guilt, admiration, flirtatiousness). Prior findings with a standardized set of stimuli indicated that recognition of social emotions can be signaled by the eye r...

  20. Learning driving behavior by timed syntactic pattern recognition

    OpenAIRE

    Verwer, S.E.; Weerdt, M.M.; C. Witteveen

    2011-01-01

    We advocate the use of an explicit time representation in syntactic pattern recognition because it can result in more succinct models and easier learning problems. We apply this approach to the real-world problem of learning models for the driving behavior of truck drivers. We discretize the values of onboard sensors into simple events. Instead of the common syntactic pattern recognition approach of sampling the signal values at a fixed rate, we model the time constraints using timed models. ...

  1. Touchless palmprint recognition systems

    CERN Document Server

    Genovese, Angelo; Scotti, Fabio

    2014-01-01

    This book examines the context, motivation and current status of biometric systems based on the palmprint, with a specific focus on touchless and less-constrained systems. It covers new technologies in this rapidly evolving field and is one of the first comprehensive books on palmprint recognition systems.It discusses the research literature and the most relevant industrial applications of palmprint biometrics, including the low-cost solutions based on webcams. The steps of biometric recognition are described in detail, including acquisition setups, algorithms, and evaluation procedures. Const

  2. Recognition as care

    DEFF Research Database (Denmark)

    Ahlmark, Nanna; Whyte, Susan Reynolds; Harting, Janneke;

    2014-01-01

    meaningful benefits; these centred on reducing isolation and being met on their own terms regarding language and logistics. Most importantly, they remembered when treated with attention and respect by professionals and the mutual acknowledgement between participants. We use Axel Honneth’s notions of rights......-based and solidarity-based recognition to analyse what was at stake in these experiences, and we engage Annemarie Mol’s concept of a logic of care to show how recognition unfolded practically during the training. We propose that participants’ wider social context and experiences of misrecognition situated the training...

  3. Comparative wavelet, PLP, and LPC speech recognition techniques on the Hindi speech digits database

    Science.gov (United States)

    Mishra, A. N.; Shrotriya, M. C.; Sharan, S. N.

    2010-02-01

    In view of the growing use of automatic speech recognition in the modern society, we study various alternative representations of the speech signal that have the potential to contribute to the improvement of the recognition performance. In this paper wavelet based features using different wavelets are used for Hindi digits recognition. The recognition performance of these features has been compared with Linear Prediction Coefficients (LPC) and Perceptual Linear Prediction (PLP) features. All features have been tested using Hidden Markov Model (HMM) based classifier for speaker independent Hindi digits recognition. The recognition performance of PLP features is11.3% better than LPC features. The recognition performance with db10 features has shown a further improvement of 12.55% over PLP features. The recognition performance with db10 is best among all wavelet based features.

  4. Chemical basis of prey recognition in thamnophiine snakes: the unexpected new roles of parvalbumins.

    Science.gov (United States)

    Smargiassi, Maïté; Daghfous, Gheylen; Leroy, Baptiste; Legreneur, Pierre; Toubeau, Gerard; Bels, Vincent; Wattiez, Ruddy

    2012-01-01

    Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO). In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins-parvalbumins-present in the cutaneous mucus of the common frog (Rana temporaria) may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca(2+) buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca(2+)-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction.

  5. Chemical basis of prey recognition in thamnophiine snakes: the unexpected new roles of parvalbumins.

    Directory of Open Access Journals (Sweden)

    Maïté Smargiassi

    Full Text Available Detecting and locating prey are key to predatory success within trophic chains. Predators use various signals through specialized visual, olfactory, auditory or tactile sensory systems to pinpoint their prey. Snakes chemically sense their prey through a highly developed auxiliary olfactory sense organ, the vomeronasal organ (VNO. In natricine snakes that are able to feed on land and water, the VNO plays a critical role in predatory behavior by detecting cues, known as vomodors, which are produced by their potential prey. However, the chemical nature of these cues remains unclear. Recently, we demonstrated that specific proteins-parvalbumins-present in the cutaneous mucus of the common frog (Rana temporaria may be natural chemoattractive proteins for these snakes. Here, we show that parvalbumins and parvalbumin-like proteins, which are mainly intracellular, are physiologically present in the epidermal mucous cells and mucus of several frog and fish genera from both fresh and salt water. These proteins are located in many tissues and function as Ca(2+ buffers. In addition, we clarified the intrinsic role of parvalbumins present in the cutaneous mucus of amphibians and fishes. We demonstrate that these Ca(2+-binding proteins participate in innate bacterial defense mechanisms by means of calcium chelation. We show that these parvalbumins are chemoattractive for three different thamnophiine snakes, suggesting that these chemicals play a key role in their prey-recognition mechanism. Therefore, we suggest that recognition of parvalbumin-like proteins or other calcium-binding proteins by the VNO could be a generalized prey-recognition process in snakes. Detecting innate prey defense mechanism compounds may have driven the evolution of this predator-prey interaction.

  6. Inter-kingdom signaling: chemical language between bacteria and host

    OpenAIRE

    Pacheco, Alline R.; Sperandio, Vanessa

    2009-01-01

    Chemical communication between cells ensures coordination of behavior. In prokaryotes, this chemical communication is usually referred to as quorum sensing, while eukaryotic cells signal through hormones. In the past years, a growing number of reports have shown that bacterial quorum sensing signals, called autoinducers, signal to eukaryotic cells, mimicking hormones. Conversely, host hormones can signal to bacterial cells through converging pathways to autoinducer signaling. This inter-kingd...

  7. Tolerance and recognition

    Directory of Open Access Journals (Sweden)

    Hans Marius Hansteen

    2014-03-01

    Full Text Available Even though “toleration” and “recognition” designate opposing attitudes (to tolerate something, implies a negative stance towards it, whereas recognition seems to imply a positive one, the concepts do not constitute mutually exclusive alternatives. However, “toleration” is often associated with liberal universalism, focusing on individual rights, whereas “recognition” often connotes communitarian perspectives, focusing on relations and identity. This paper argues that toleration may be founded on recognition, and that recognition may imply toleration. In outlining a differentiated understanding of the relationship between toleration and recognition, it seems apt to avoid an all-to-general dichotomy between universalism and particularism or, in other words, to reach beyond the debate between liberalism and communitarianism in political philosophy.The paper takes as its starting point the view that the discussion on toleration and diversity in intercultural communication is one of the contexts where it seems important to get beyond the liberal/communitarian dichotomy. Some basic features of Rainer Forst’s theory of toleration and Axel Honneth’s theory of the struggle for recognition are presented, in order to develop a more substantial understanding of the relationship between the concepts of toleration and recognition. One lesson from Forst is that toleration is a normatively dependent concept, i.e., that it is impossible to deduce principles for toleration and its limits from a theory of toleration as such. A central lesson from Honneth is that recognition – understood as a basic human need – is always conflictual and therefore dynamic.Accordingly, a main point in the paper is that the theory of struggles for and about recognition (where struggles for designates struggles within an established order of recognition, and struggles about designates struggles that challenge established orders of recognition may clarify what

  8. Wavelets and Face Recognition

    OpenAIRE

    Dai, Dao-Qing; Yan, Hong

    2007-01-01

    Wavelets have been successfully used in image processing. Their ability to capture localized spatial-frequency information of image motivates their use for feature extraction. We give an overview of using wavelets in the face recognition technology. Due to limit of space the use of Gabor wavelets is not covered in this survey. Interested readers are referred to section 8.3 for references.

  9. Recognition of fractal graphs

    NARCIS (Netherlands)

    Perepelitsa, VA; Sergienko, [No Value; Kochkarov, AM

    1999-01-01

    Definitions of prefractal and fractal graphs are introduced, and they are used to formulate mathematical models in different fields of knowledge. The topicality of fractal-graph recognition from the point of view, of fundamental improvement in the efficiency of the solution of algorithmic problems i

  10. FINGERPRINT RECOGNITION SYSTEM DESIGN

    OpenAIRE

    SONMEZ, Öznur Sinem; OZTAS, Oguzhan

    2010-01-01

    In this study, a minutiae-based fingerprint recognition system is implemented which includes normalization, enhancement, thinning, extraction of minutiae, elimination of false minutiae, orientation estimation, core point detection, finding reference points and matching processes. Accordingly, the effects of enhancement and elimination of false minutiae processes, methods of reference point determination and low quality fingerprint images on system performance are analyzed using two different ...

  11. Pattern recognition in bioinformatics.

    Science.gov (United States)

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

    2013-09-01

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

  12. Visually mediated species and neighbour recognition in fiddler crabs (Uca mjoebergi and Uca capricornis)

    OpenAIRE

    Detto, Tanya; Backwell, Patricia R. Y.; Jan M Hemmi; Zeil, Jochen

    2006-01-01

    Mating signals are often directed at numerous senses and provide information about species identity, gender, receptiveness, individual identity and mate quality. Given the diversity of colourful body patterns in invertebrates, surprisingly few studies have examined the role of these visual signals in mate recognition. Here, we demonstrate the use of claw coloration as a species recognition signal in a fiddler crab (Uca mjoebergi). Furthermore, we show that distinct carapace colour patterns in...

  13. Cooperative Model of Bacterial Sensing

    CERN Document Server

    Shi, Y; Shi, Yu; Duke, Thomas

    1998-01-01

    Bacterial chemotaxis is controlled by the signalling of a cluster of receptors. A cooperative model is presented, in which coupling between neighbouring receptor dimers enhances the sensitivity with which stimuli can be detected, without diminishing the range of chemoeffector concentration over which chemotaxis can operate. Individual receptor dimers have two stable conformational states: one active, one inactive. Noise gives rise to a distribution between these states, with the probability influenced by ligand binding, and also by the conformational states of adjacent receptor dimers. The two-state model is solved, based on an equivalence with the Ising model in a randomly distributed magnetic field. The model has only two effective parameters, and unifies a number of experimental findings. According to the value of the parameter comparing coupling and noise, the signal can be arbitrarily sensitive to changes in the fraction of receptor dimers to which ligand is bound. The counteracting effect of a change of...

  14. The Bacterial Microflora of Fish, Revised

    Directory of Open Access Journals (Sweden)

    B. Austin

    2006-01-01

    Full Text Available The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen of healthy fish may contain bacteria, but there is debate about whether or not muscle is actually sterile. Using traditional culture-dependent techniques, the numbers and taxonomic composition of the bacterial populations generally reflect those of the surrounding water. More modern culture-independent approaches have permitted the recognition of previously uncultured bacteria. The role of the organisms includes the ability to degrade complex molecules (therefore exercising a potential benefit in nutrition, to produce vitamins and polymers, and to be responsible for the emission of light by the light-emitting organs of deep-sea fish. Taxa, including Pseudomonas, may contribute to spoilage by the production of histamines in fish tissue.

  15. Stereotype Associations and Emotion Recognition

    NARCIS (Netherlands)

    Bijlstra, Gijsbert; Holland, Rob W.; Dotsch, Ron; Hugenberg, Kurt; Wigboldus, Daniel H. J.

    2014-01-01

    We investigated whether stereotype associations between specific emotional expressions and social categories underlie stereotypic emotion recognition biases. Across two studies, we replicated previously documented stereotype biases in emotion recognition using both dynamic (Study 1) and static (Stud

  16. Speech recognition: Acoustic, phonetic and lexical knowledge

    Science.gov (United States)

    Zue, V. W.

    1985-08-01

    During this reporting period we continued to make progress on the acquisition of acoustic-phonetic and lexical knowledge. We completed development of a continuous digit recognition system. The system was constructed to investigate the use of acoustic-phonetic knowledge in a speech recognition system. The significant achievements of this study include the development of a soft-failure procedure for lexical access and the discovery of a set of acoustic-phonetic features for verification. We completed a study of the constraints that lexical stress imposes on word recognition. We found that lexical stress information alone can, on the average, reduce the number of word candidates from a large dictionary by more than 80 percent. In conjunction with this study, we successfully developed a system that automatically determines the stress pattern of a word from the acoustic signal. We performed an acoustic study on the characteristics of nasal consonants and nasalized vowels. We have also developed recognition algorithms for nasal murmurs and nasalized vowels in continuous speech. We finished the preliminary development of a system that aligns a speech waveform with the corresponding phonetic transcription.

  17. Face recognition increases during saccade preparation.

    Directory of Open Access Journals (Sweden)

    Hai Lin

    Full Text Available Face perception is integral to human perception system as it underlies social interactions. Saccadic eye movements are frequently made to bring interesting visual information, such as faces, onto the fovea for detailed processing. Just before eye movement onset, the processing of some basic features, such as the orientation, of an object improves at the saccade landing point. Interestingly, there is also evidence that indicates faces are processed in early visual processing stages similar to basic features. However, it is not known whether this early enhancement of processing includes face recognition. In this study, three experiments were performed to map the timing of face presentation to the beginning of the eye movement in order to evaluate pre-saccadic face recognition. Faces were found to be similarly processed as simple objects immediately prior to saccadic movements. Starting ∼ 120 ms before a saccade to a target face, independent of whether or not the face was surrounded by other faces, the face recognition gradually improved and the critical spacing of the crowding decreased as saccade onset was approaching. These results suggest that an upcoming saccade prepares the visual system for new information about faces at the saccade landing site and may reduce the background in a crowd to target the intended face. This indicates an important role of pre-saccadic eye movement signals in human face recognition.

  18. Pedestrian recognition using automotive radar sensors

    Science.gov (United States)

    Bartsch, A.; Fitzek, F.; Rasshofer, R. H.

    2012-09-01

    The application of modern series production automotive radar sensors to pedestrian recognition is an important topic in research on future driver assistance systems. The aim of this paper is to understand the potential and limits of such sensors in pedestrian recognition. This knowledge could be used to develop next generation radar sensors with improved pedestrian recognition capabilities. A new raw radar data signal processing algorithm is proposed that allows deep insights into the object classification process. The impact of raw radar data properties can be directly observed in every layer of the classification system by avoiding machine learning and tracking. This gives information on the limiting factors of raw radar data in terms of classification decision making. To accomplish the very challenging distinction between pedestrians and static objects, five significant and stable object features from the spatial distribution and Doppler information are found. Experimental results with data from a 77 GHz automotive radar sensor show that over 95% of pedestrians can be classified correctly under optimal conditions, which is compareable to modern machine learning systems. The impact of the pedestrian's direction of movement, occlusion, antenna beam elevation angle, linear vehicle movement, and other factors are investigated and discussed. The results show that under real life conditions, radar only based pedestrian recognition is limited due to insufficient Doppler frequency and spatial resolution as well as antenna side lobe effects.

  19. Optical correlation recognition based on LCOS

    Science.gov (United States)

    Tang, Mingchuan; Wu, Jianhong

    2013-08-01

    Vander-Lugt correlator[1] plays an important role in optical pattern recognition due to the characteristics of accurate positioning and high signal-to-noise ratio. The ideal Vander-Lugt correlator should have the ability of outputting strong and sharp correlation peak in allusion to the true target, in the existing Spatial Light Modulators[2], Liquid Crystal On Silicon(LCOS) has been the most competitive candidate for the matched filter owing to the continuous phase modulation peculiarity. Allowing for the distortions of the target to be identified including rotations, scaling changes, perspective changes, which can severely impact the correlation recognition results, herein, we present a modified Vander-Lugt correlator based on the LCOS by means of applying an iterative algorithm to the design of the filter so that the correlator can invariant to the distortions while maintaining good performance. The results of numerical simulation demonstrate that the filter could get the similar recognition results for all the training images. And the experiment shows that the modified correlator achieves the 180° rotating tolerance significantly improving the recognition efficiency of the correlator.

  20. The Vibration Signal Recognition of Optical Fiber Perimeter Based on Time-frequency Features%基于时频特征的光纤周界振动信号识别

    Institute of Scientific and Technical Information of China (English)

    朱程辉; 瞿永中; 王建平

    2014-01-01

    在光纤周界安防系统中,蓄意入侵和环境噪声均能引起光纤传感器振动,在保证系统高灵敏度的前提下区分入侵和非入侵事件极为重要。为了有效识别各种光纤振动信号,本文依据入侵和环境噪声引起的光纤振动信号在时域上的短时特性以及复小波域各尺度上能量分布特征,提出了两级判别法识别光纤信号。第一级用时域特征,短时能量和短时平均过零率判断是否有振动发生;第二级用复小波提取光纤信号的能量分布特征,联合时域特征形成特征矢量,支持向量机(SVM)作为分类器识别是否为入侵信号及入侵类型。实验结果表明,此方法可以有效识别入侵信号和环境噪声引起的非入侵事件,提高了系统报警率,降低了误报率。%In the optical fiber perimeter security system, both deliberate invasion and environmental noise can cause optical fiber sensor vibration. It is very important to distinguish the invasion and no invasion events under ensuring the high sensitivity of system. In order to identify the various fiber optic vibration signals effectively, we propose two-stage discriminative method based on the invasion and environmental noise vibration signals short features on time-domain as well as scale energy distribution on complex wavelet domain to recognize the fiber optic signal. The first level use the time-domain characteristics of short-time energy and short-time zero crossing rate to judge whether there is a vibration happening. The second level use complex wavelet extraction the energy distribution features, combining with the time domain characteristics form the characteristic vector, Support Vector Machine (SVM) as the classifier to identify whether it is a intrusion signal and intrusion type. The experiment results show that this method can identify the intrusion signals and environment noise signals effectively, improve the system alarm rate and reduce

  1. Bacterial tactic responses.

    Science.gov (United States)

    Armitage, J P

    1999-01-01

    Many, if not most, bacterial species swim. The synthesis and operation of the flagellum, the most complex organelle of a bacterium, takes a significant percentage of cellular energy, particularly in the nutrient limited environments in which many motile species are found. It is obvious that motility accords cells a survival advantage over non-motile mutants under normal, poorly mixed conditions and is an important determinant in the development of many associations between bacteria and other organisms, whether as pathogens or symbionts and in colonization of niches and the development of biofilms. This survival advantage is the result of sensory control of swimming behaviour. Although too small to sense a gradient along the length of the cell, and unable to swim great distances because of buffetting by Brownian motion and the curvature resulting from a rotating flagellum, bacteria can bias their random swimming direction towards a more favourable environment. The favourable environment will vary from species to species and there is now evidence that in many species this can change depending on the current physiological growth state of the cell. In general, bacteria sense changes in a range of nutrients and toxins, compounds altering electron transport, acceptors or donors into the electron transport chain, pH, temperature and even the magnetic field of the Earth. The sensory signals are balanced, and may be balanced with other sensory pathways such as quorum sensing, to identify the optimum current environment. The central sensory pathway in this process is common to most bacteria and most effectors. The environmental change is sensed by a sensory protein. In most species examined this is a transmembrane protein, sensing the external environment, but there is increasing evidence for additional cytoplasmic receptors in many species. All receptors, whether sensing sugars, amino acids or oxygen, share a cytoplasmic signalling domain that controls the activity of a

  2. RECOGNITION AND ASSESSMENT IN ACCOUNTANCY

    Directory of Open Access Journals (Sweden)

    DIMA FLORIN CONSTANTIN

    2012-11-01

    Full Text Available The recognition and assessment of the component elements of the annual financial statements’ structures is crucial in order that the information released by them fulfils the qualitative characteristics and the reflected image is a “true and fair view”. Therefore, our approach takes into consideration the recognition and assessment methods for the component elements of the financial statements’ structures, as well as certain possible risks arising from the erroneous recognition or non-recognition of some of these elements.

  3. The enzymes of bacterial census and censorship.

    Science.gov (United States)

    Fast, Walter; Tipton, Peter A

    2012-01-01

    N-Acyl-L-homoserine lactones (AHLs) are a major class of quorum-sensing signals used by Gram-negative bacteria to regulate gene expression in a population-dependent manner, thereby enabling group behavior. Enzymes capable of generating and catabolizing AHL signals are of significant interest for the study of microbial ecology and quorum-sensing pathways, for understanding the systems that bacteria have evolved to interact with small-molecule signals, and for their possible use in therapeutic and industrial applications. The recent structural and functional studies reviewed here provide a detailed insight into the chemistry and enzymology of bacterial communication. PMID:22099187

  4. The enzymes of bacterial census and censorship.

    Science.gov (United States)

    Fast, Walter; Tipton, Peter A

    2012-01-01

    N-Acyl-L-homoserine lactones (AHLs) are a major class of quorum-sensing signals used by Gram-negative bacteria to regulate gene expression in a population-dependent manner, thereby enabling group behavior. Enzymes capable of generating and catabolizing AHL signals are of significant interest for the study of microbial ecology and quorum-sensing pathways, for understanding the systems that bacteria have evolved to interact with small-molecule signals, and for their possible use in therapeutic and industrial applications. The recent structural and functional studies reviewed here provide a detailed insight into the chemistry and enzymology of bacterial communication.

  5. Doing Justice to Recognition

    Directory of Open Access Journals (Sweden)

    Will Colish

    2009-06-01

    Full Text Available The traditional role of justice is to arbitrate where the good will of people is not enough, if even present, to settle a dispute between the concerned parties. It is a procedural approach that assumes a fractured relationship between those involved. Recognition, at first glance, would not seem to mirror these aspects of justice. Yet recognition is very much a subject of justice these days. The aim of this paper is to question the applicability of justice to the practice of recognition. The methodological orientation of this paper is a Kantian-style critique of the institution of justice, highlighting the limits of its reach and the dangers of overextension. The critique unfolds in the following three steps: 1 There is an immediate appeal to justice as a practice of recognition through its commitment to universality. This allure is shown to be deceptive in providing no prescription for the actual practice of this universality. 2 The interventionist character of justice is designed to address divided relationships. If recognition is only given expression through this channel, then we can only assume division as our starting ground. 3 The outcome of justice in respect to recognition is identification. This identification is left vulnerable to misrecognition itself, creating a cycle of injustice that demands recognition from anew. It seems to be well accepted that recognition is essentjustice, but less clear how to do justice to recognition. This paper is an effort in clarification. Le rôle traditionnel de la justice est celui d’arbitrer des situations où la bonne volonté ne suffit pas à régler un différend entre les parties concernées. Il s'agit d'une approche procédurale qui suppose une relation brisée entre les personnes impliquées. La reconnaissance, à première vue, ne semble pas refléter ces caractéristiques de la justice. Pourtant, elle est souvent présentée comme rétablissant une justice entre les parties concernés. Le

  6. Supporting Quality Teachers with Recognition

    Science.gov (United States)

    Andrews, Hans A.

    2011-01-01

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

  7. 3D modelling and recognition

    OpenAIRE

    Rodrigues, Marcos; Robinson, Alan; Alboul, Lyuba; Brink, Willie

    2006-01-01

    3D face recognition is an open field. In this paper we present a method for 3D facial recognition based on Principal Components Analysis. The method uses a relatively large number of facial measurements and ratios and yields reliable recognition. We also highlight our approach to sensor development for fast 3D model acquisition and automatic facial feature extraction.

  8. Forensic Face Recognition: A Survey

    NARCIS (Netherlands)

    Ali, Tauseef; Spreeuwers, Luuk; Veldhuis, Raymond; 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

  9. IRIS Based Human Recognition System

    Directory of Open Access Journals (Sweden)

    Mansi Jhamb, Vinod Kumar Khera

    2011-04-01

    Full Text Available The paper explores iris recognition for personal identification and verification. In this paper a newiris recognition technique is proposed using (Scale Invariant Feature Transform SIFT. Imageprocessingalgorithms have been validated on noised real iris image database. The proposedinnovative technique is computationally effective as well as reliable in terms of recognition rates.

  10. Galeotti on recognition as inclusion

    DEFF Research Database (Denmark)

    Lægaard, Sune

    2008-01-01

    out Galeotti's justification for recognition as a requirement of liberal justice in detail and asks in what sense the policies supported by Galeotti are policies of recognition. It is argued that Jones misrepresents Galeotti's theory, insofar as this sense of recognition actually is compatible...

  11. Small molecule control of bacterial biofilms.

    Science.gov (United States)

    Worthington, Roberta J; Richards, Justin J; Melander, Christian

    2012-10-01

    Bacterial biofilms are defined as a surface attached community of bacteria embedded in a matrix of extracellular polymeric substances that they have produced. When in the biofilm state, bacteria are more resistant to antibiotics and the host immune response than are their planktonic counterparts. Biofilms are increasingly recognized as being significant in human disease, accounting for 80% of bacterial infections in the body and diseases associated with bacterial biofilms include: lung infections of cystic fibrosis patients, colitis, urethritis, conjunctivitis, otitis, endocarditis and periodontitis. Additionally, biofilm infections of indwelling medical devices are of particular concern, as once the device is colonized infection is virtually impossible to eradicate. Given the prominence of biofilms in infectious diseases, there has been an increased effort toward the development of small molecules that will modulate bacterial biofilm development and maintenance. In this review, we highlight the development of small molecules that inhibit and/or disperse bacterial biofilms through non-microbicidal mechanisms. The review discuses the numerous approaches that have been applied to the discovery of lead small molecules that mediate biofilm development. These approaches are grouped into: (1) the identification and development of small molecules that target one of the bacterial signaling pathways involved in biofilm regulation, (2) chemical library screening for compounds with anti-biofilm activity, and (3) the identification of natural products that possess anti-biofilm activity, and the chemical manipulation of these natural products to obtain analogues with increased activity. PMID:22733439

  12. Hand Gesture Recognition Using Ultrasonic Waves

    KAUST Repository

    AlSharif, Mohammed Hussain

    2016-04-01

    Gesturing is a natural way of communication between people and is used in our everyday conversations. Hand gesture recognition systems are used in many applications in a wide variety of fields, such as mobile phone applications, smart TVs, video gaming, etc. With the advances in human-computer interaction technology, gesture recognition is becoming an active research area. There are two types of devices to detect gestures; contact based devices and contactless devices. Using ultrasonic waves for determining gestures is one of the ways that is employed in contactless devices. Hand gesture recognition utilizing ultrasonic waves will be the focus of this thesis work. This thesis presents a new method for detecting and classifying a predefined set of hand gestures using a single ultrasonic transmitter and a single ultrasonic receiver. This method uses a linear frequency modulated ultrasonic signal. The ultrasonic signal is designed to meet the project requirements such as the update rate, the range of detection, etc. Also, it needs to overcome hardware limitations such as the limited output power, transmitter, and receiver bandwidth, etc. The method can be adapted to other hardware setups. Gestures are identified based on two main features; range estimation of the moving hand and received signal strength (RSS). These two factors are estimated using two simple methods; channel impulse response (CIR) and cross correlation (CC) of the reflected ultrasonic signal from the gesturing hand. A customized simple hardware setup was used to classify a set of hand gestures with high accuracy. The detection and classification were done using methods of low computational cost. This makes the proposed method to have a great potential for the implementation in many devices including laptops and mobile phones. The predefined set of gestures can be used for many control applications.

  13. Bacterial infections in cirrhosis: A critical review andpractical guidance

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    Bacterial infection is common and accounts for majormorbidity and mortality in cirrhosis. Patients withcirrhosis are immunocompromised and increased susceptibilityto develop spontaneous bacterial infections,hospital-acquired infections, and a variety of infectionsfrom uncommon pathogens. Once infection develops,the excessive response of pro-inflammatory cytokineson a pre-existing hemodynamic dysfunction in cirrhosisfurther predispose the development of serious complicationssuch as shock, acute-on-chronic liver failure, renalfailure, and death. Spontaneous bacterial peritonitisand bacteremia are common in patients with advancedcirrhosis, and are important prognostic landmarks inthe natural history of cirrhosis. Notably, the incidenceof infections from resistant bacteria has increasedsignificantly in healthcare-associated settings. Serumbiomarkers such as procalcitonin may help to improvethe diagnosis of bacterial infection. Preventive measures(e.g. , avoidance, antibiotic prophylaxis, and vaccination),early recognition, and proper management are requiredin order to minimize morbidity and mortality of infectionsin cirrhosis.

  14. DWT BASED IRIS RECOGNITION

    Directory of Open Access Journals (Sweden)

    MAYURI MEMANE

    2012-08-01

    Full Text Available The iris recognition is an emerging technology widely used due to various characteristics such as uniqueness,universal, stable, independent of genetics, acceptable etc. The recognition is carried out using discrete wavelet transform (DWT. It includes collection of iris database, carrying out preprocessing (includes separation ofpupil, normalization and feature extraction. Normalization includes polar to rectangular conversion. After this area of interest is selected from which features are extracted using DWT. It generates approximate, horizontal, vertical and diagonal coefficients. These are compared with the stored templates using hamming distance. If thetemplate is match with the stored one than the match ID is displayed. The unauthorized person is indicated by displaying ID equal to ‘00’

  15. Audio-visual gender recognition

    Science.gov (United States)

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

    2007-11-01

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

  16. Vehicle License Plate Recognition Syst

    Directory of Open Access Journals (Sweden)

    Meenakshi,R. B. Dubey

    2012-12-01

    Full Text Available The vehicle license plate recognition system has greater efficiency for vehicle monitoring in automatic zone access control. This Plate recognition system will avoid special tags, since all vehicles possess a unique registration number plate. A number of techniques have been used for car plate characters recognition. This system uses neural network character recognition and pattern matching of characters as two character recognition techniques. In this approach multilayer feed-forward back-propagation algorithm is used. The performance of the proposed algorithm has been tested on several car plates and provides very satisfactory results.

  17. Human Recognition System using Cepstral Information

    Directory of Open Access Journals (Sweden)

    Emna RABHI

    2014-05-01

    Full Text Available This paper presents a new method for human recognition using the cepstral information. The proposed method consists in extracting the Linear Frequency Cepstral Coefficients (LFCC from each heartbeat in the homomorphic domain. Thus, the Hidden Markov Model (HMM under Hidden Markov Model Toolkit (HTK is used for electrocardiogram (ECG classification. To evaluate the performance of the classifier, the number of coefficients and the number of frequency bands are varied. Concerning the HMM topology, the number of Gaussians and states are also varied. The best rate is obtained with 32 coefficients, 24 frequency bands, 1 Gaussian and 5 states. Further, the method is improved by adding dynamic features: the first order delta (? and energy (E to the coefficients. The approach is evaluated on 18 healthy signals of the MIT_BIH database. The obtained results reveal which LFCC with energy that make a 33 dimensional feature vector leads to the best human recognition rate which is 99.33%.

  18. Infrared face recognition

    OpenAIRE

    Lee, Colin K.

    2004-01-01

    Approved for public release, distribution is unlimited This study continues a previous face recognition investigation using uncooled infrared technology. The database developed in an earlier study is further expanded to include 50 volunteers with 30 facial images from each subject. The automatic image reduction method reduces the pixel size of each image from 160 120 to 60 45 . The study reexamines two linear classification methods: the Principal Component Analysis (PCA) and Fisher ...

  19. Automatic pattern recognition

    OpenAIRE

    Petheram, R.J.

    1989-01-01

    In this thesis the author presents a new method for the location, extraction and normalisation of discrete objects found in digital images. The extraction is by means of sub-pixcel contour following around the object. The normalisation obtains and removes the information concerning size, orientation and location of the object within an image. Analyses of the results are carried out to determine the confidence in recognition of patterns, and methods of cross correlation of object descriptions ...

  20. Facial Expression Recognition

    OpenAIRE

    Neeta Sarode; Prof. Shalini Bhatia

    2010-01-01

    Facial expression analysis is rapidly becoming an area of intense interest in computer science and human-computer interaction design communities. The most expressive way humans display emotions is through facial expressions. In this paper a method is implemented using 2D appearance-based local approach for the extraction of intransient facial features and recognition of four facial expressions. The algorithm implements Radial Symmetry Transform and further uses edge projection analysis for fe...

  1. Recognition of Teaching Excellence*

    OpenAIRE

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

    2010-01-01

    The 2008-2009 Task Force for the Recognition of Teaching Excellence was charged by the AACP Council of Faculties Leadership to examine teaching excellence by collecting best practices from colleges and schools of pharmacy, evaluating the literature to identify evidence-based criteria for excellent teaching, and recommending appropriate means to acknowledge and reward teaching excellence. This report defines teaching excellence and discusses a variety of ways to assess it, including student, a...

  2. Adaptive Compensation Algorithm in Open Vocabulary Mandarin Speaker-Independent Speech Recognition

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In speech recognition systems, the physiological characteristics of the speech production model cause the voiced sections of the speech signal to have an attenuation of approximately 20 dB per decade. Many speech recognition algorithms have been developed to solve this problem by filtering the input signal with a single-zero high pass filter. Unfortunately, this technique increases the noise energy at high frequencies above 4 kHz, which in some cases degrades the recognition accuracy. This paper solves the problem using a pre-emphasis filter in the front end of the recognizer. The aim is to develop a modified parameterization approach taking into account the whole energy zone in the spectrum to improve the performance of the existing baseline recognition system in the acoustic phase. The results show that a large vocabulary speaker-independent continuous speech recognition system using this approach has a greatly improved recognition rate.

  3. 相关性分析和最大最小蚁群算法用于脉搏信号的情感识别%Affective Recognition from Pulse Signal Using Correlation Analysis and Max-Min Ant Colony Algorithm

    Institute of Scientific and Technical Information of China (English)

    陈红; 刘光远; 赖祥伟

    2012-01-01

    For the affective recognition from pulse signal,a new approach was presented, which combined correlation a-nalysis and max-min ant colony algorithm. The effective feature subset which can identify the affective recognition model with better performance was found. Firstly, sequential backward selection(SBS) was used for sorting the original features. Secondly, the linear correlation coefficient was presented for calculating the correlation between features, and some features were removed which had greater correlation according to the result of sorting. Finally,max-min ant colony algorithm realized feature selection which searched for an optimal subset based on the compact feature subset,and combined with Fisher classifier to finish classification of six emotions which include happiness,surprise,disgust,grief,anger and fear. The experiments show that the proposed approach can find the more stable and effective feature subset from the original feature set, and establish effective affective recognition model.%针对脉搏信号的情感识别问题,提出了一种相关性分析和最大最小蚁群算法相结合的方法,找出了对情感识别模型构建具有较好性能的稳定特征子集.首先将原始特征用序列后向选择(SBS)方法排序,然后利用线性相关系数分析法计算特征间的相关度,并根据排序结果去除部分相关度较大的特征,最后针对筛选后的特征子集用最大最小蚁群算法进行特征选择,并结合Fisher分类器对高兴、惊奇、厌恶、悲伤、愤怒和恐惧6种情感进行分类.实验结果表明,该方法能在原始特征集合中找出更稳定有效的特征子集,从而建立起有效的情感识别模型.

  4. 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

  5. Source Separation via Spectral Masking for Speech Recognition Systems

    Directory of Open Access Journals (Sweden)

    Gustavo Fernandes Rodrigues

    2012-12-01

    Full Text Available In this paper we present an insight into the use of spectral masking techniques in time-frequency domain, as a preprocessing step for the speech signal recognition. Speech recognition systems have their performance negatively affected in noisy environments or in the presence of other speech signals. The limits of these masking techniques for different levels of the signal-to-noise ratio are discussed. We show the robustness of the spectral masking techniques against four types of noise: white, pink, brown and human speech noise (bubble noise. The main contribution of this work is to analyze the performance limits of recognition systems  using spectral masking. We obtain an increase of 18% on the speech hit rate, when the speech signals were corrupted by other speech signals or bubble noise, with different signal-to-noise ratio of approximately 1, 10 and 20 dB. On the other hand, applying the ideal binary masks to mixtures corrupted by white, pink and brown noise, results an average growth of 9% on the speech hit rate, with the same different signal-to-noise ratio. The experimental results suggest that the masking spectral techniques are more suitable for the case when it is applied a bubble noise, which is produced by human speech, than for the case of applying white, pink and brown noise.

  6. Gene network homology in prokaryotes using a similarity search approach: queries of quorum sensing signal transduction.

    Directory of Open Access Journals (Sweden)

    David N Quan

    Full Text Available Bacterial cell-cell communication is mediated by small signaling molecules known as autoinducers. Importantly, autoinducer-2 (AI-2 is synthesized via the enzyme LuxS in over 80 species, some of which mediate their pathogenicity by recognizing and transducing this signal in a cell density dependent manner. AI-2 mediated phenotypes are not well understood however, as the means for signal transduction appears varied among species, while AI-2 synthesis processes appear conserved. Approaches to reveal the recognition pathways of AI-2 will shed light on pathogenicity as we believe recognition of the signal is likely as important, if not more, than the signal synthesis. LMNAST (Local Modular Network Alignment Similarity Tool uses a local similarity search heuristic to study gene order, generating homology hits for the genomic arrangement of a query gene sequence. We develop and apply this tool for the E. coli lac and LuxS regulated (Lsr systems. Lsr is of great interest as it mediates AI-2 uptake and processing. Both test searches generated results that were subsequently analyzed through a number of different lenses, each with its own level of granularity, from a binary phylogenetic representation down to trackback plots that preserve genomic organizational information. Through a survey of these results, we demonstrate the identification of orthologs, paralogs, hitchhiking genes, gene loss, gene rearrangement within an operon context, and also horizontal gene transfer (HGT. We found a variety of operon structures that are consistent with our hypothesis that the signal can be perceived and transduced by homologous protein complexes, while their regulation may be key to defining subsequent phenotypic behavior.

  7. Facial Expression Recognition via Non-Negative Least-Squares Sparse Coding

    OpenAIRE

    Ying Chen; Shiqing Zhang; Xiaoming Zhao

    2014-01-01

    Sparse coding is an active research subject in signal processing, computer vision, and pattern recognition. A novel method of facial expression recognition via non-negative least squares (NNLS) sparse coding is presented in this paper. The NNLS sparse coding is used to form a facial expression classifier. To testify the performance of the presented method, local binary patterns (LBP) and the raw pixels are extracted for facial feature representation. Facial expression recognition experiments ...

  8. Vowel recognition of patients after total laryngectomy using Mel Frequency Cepstral Coefficients and mouth contour

    Directory of Open Access Journals (Sweden)

    Pietruch Rafal W.

    2010-01-01

    Full Text Available The paper addresses a problem of isolated vowels recognition in patients following total laryngectomy. The visual and acoustic speech modalities were separately incorporated in the machine learning algorithms. The authors used the Mel Frequency Cepstral Coefficients as acoustic descriptors of a speech signal. A lip contour was extracted from a video signal of the speaking faces using OpenCV software library. In a vowels recognition procedure the three types of classifiers were used for comparison purposes: Artificial Neural Networks, Support Vector Machines and Naive Bayes. The highest recognition rate was evaluated using Support Vector Machines. For a group of the laryngectomees having a different quality of speech the authors achieved 75% for acoustic and 40% for visual recognition performances. The authors obtained higher recognition rate than in a previous research where 10 cross-sectional areas of a vocal tract were estimated. Using presented image processing algorithm the visual features can be extracted automatically from a video signal.

  9. When the face fits: recognition of celebrities from matching and mismatching faces and voices.

    Science.gov (United States)

    Stevenage, Sarah V; Neil, Greg J; Hamlin, Iain

    2014-01-01

    The results of two experiments are presented in which participants engaged in a face-recognition or a voice-recognition task. The stimuli were face-voice pairs in which the face and voice were co-presented and were either "matched" (same person), "related" (two highly associated people), or "mismatched" (two unrelated people). Analysis in both experiments confirmed that accuracy and confidence in face recognition was consistently high regardless of the identity of the accompanying voice. However accuracy of voice recognition was increasingly affected as the relationship between voice and accompanying face declined. Moreover, when considering self-reported confidence in voice recognition, confidence remained high for correct responses despite the proportion of these responses declining across conditions. These results converged with existing evidence indicating the vulnerability of voice recognition as a relatively weak signaller of identity, and results are discussed in the context of a person-recognition framework. PMID:23531227

  10. Electrocardiogram (ECG) pattern modeling and recognition via deterministic learning

    Institute of Scientific and Technical Information of China (English)

    Xunde DONG; Cong WANG; Junmin HU; Shanxing OU

    2014-01-01

    A method for electrocardiogram (ECG) pattern modeling and recognition via deterministic learning theory is presented in this paper. Instead of recognizing ECG signals beat-to-beat, each ECG signal which contains a number of heartbeats is recognized. The method is based entirely on the temporal features (i.e., the dynamics) of ECG patterns, which contains complete information of ECG patterns. A dynamical model is employed to demonstrate the method, which is capable of generating synthetic ECG signals. Based on the dynamical model, the method is shown in the following two phases:the identification (training) phase and the recognition (test) phase. In the identification phase, the dynamics of ECG patterns is accurately modeled and expressed as constant RBF neural weights through the deterministic learning. In the recognition phase, the modeling results are used for ECG pattern recognition. The main feature of the proposed method is that the dynamics of ECG patterns is accurately modeled and is used for ECG pattern recognition. Experimental studies using the Physikalisch-Technische Bundesanstalt (PTB) database are included to demonstrate the effectiveness of the approach.

  11. Molecular mechanisms involved in bacterial speck disease resistance of tomato

    OpenAIRE

    Gu, Y.-Q.

    1998-01-01

    An important recent advance in the field of plant-microbe interactions has been the cloning of genes that confer resistance to specific viruses, bacteria, fungi or nematodes. Disease resistance (R) genes encode proteins with predicted structural motifs consistent with them having roles in signal recognition and transduction. The future challenge is to understand how R gene products specifically perceive defence-eliciting signals from the pathogen and transduce those signals to pathways that l...

  12. Facial Emotion Recognition Using Context Based Multimodal Approach

    Directory of Open Access Journals (Sweden)

    Priya Metri

    2011-12-01

    Full Text Available Emotions play a crucial role in person to person interaction. In recent years, there has been a growing interest in improving all aspects of interaction between humans and computers. The ability to understand human emotions is desirable for the computer in several applications especially by observing facial expressions. This paper explores a ways of human-computer interaction that enable the computer to be more aware of the user’s emotional expressions we present a approach for the emotion recognition from a facial expression, hand and body posture. Our model uses multimodal emotion recognition system in which we use two different models for facial expression recognition and for hand and body posture recognition and then combining the result of both classifiers using a third classifier which give the resulting emotion . Multimodal system gives more accurate result than a signal or bimodal system

  13. 3D Face Recognition with Sparse Spherical Representations

    CERN Document Server

    Llonch, R Sala; Tosic, I; Frossard, P

    2008-01-01

    This paper addresses the problem of 3D face recognition using simultaneous sparse approximations on the sphere. The 3D face point clouds are first aligned with a novel and fully automated registration process. They are then represented as signals on the 2D sphere in order to preserve depth and geometry information. Next, we implement a dimensionality reduction process with simultaneous sparse approximations and subspace projection. It permits to represent each 3D face by only a few spherical functions that are able to capture the salient facial characteristics, and hence to preserve the discriminant facial information. We eventually perform recognition by effective matching in the reduced space, where Linear Discriminant Analysis can be further activated for improved recognition performance. The 3D face recognition algorithm is evaluated on the FRGC v.1.0 data set, where it is shown to outperform classical state-of-the-art solutions that work with depth images.

  14. Transform based Visual Features for Bimodal Recognition of Hindi Visemes

    Directory of Open Access Journals (Sweden)

    Priyanka Varshney

    2012-06-01

    Full Text Available Visual information along with audio is important for human machine interface. It not only increases the accuracy of an Audio Speech Recognition (ASR but also improves its robustness. This paper presents an overview of different approaches used for viseme recognition and also reports the new results for Hindi viseme recognition. The visemes were extracted from a database prepared from continuous sentences uttered by 5 native Hindi speakers. For audio features mel frequency cepstral coefficients (MFCCs were used while discrete wavelet transform (DWT followed by discrete cosine transform (DCT was used for visual feature extraction. The features extracted were then given to discriminant function based classifier. The maximum improvement in the recognition performance of 10.72 % is achieved at -5 dB signals to noise ratio (SNR.

  15. Optical Correlator for Face Recognition Using Collinear Holographic System

    Science.gov (United States)

    Watanabe, Eriko; Kodate, Kashiko

    2006-08-01

    We have constructed an optical correlator for fast face recognition. Recognition rate can be markedly improved, if reference images are optically recorded and can be accessed directly without converting them to digital signals. In addition, a large capacity of optical storage allows us to increase the size of the reference database. We propose a new optical correlator that integrates the optical correlation technology used in our face recognition system and collinear holography. From preliminary correlation experiments using the collinear optical set-up, we achieved excellent performance of high correlation peaks and low error rates. We expect an optical correlation of 10 μs/frame, i.e., 100,000 face/s when applied to face recognition. This system can also be applied to various image searches.

  16. Signal-to-Signal Ratio Independent Speaker Identification for Co-channel Speech Signals

    DEFF Research Database (Denmark)

    Saeidi, Rahim; Mowlaee, Pejman; Kinnunen, Tomi;

    2010-01-01

    In this paper, we consider speaker identification for the co-channel scenario in which speech mixture from speakers is recorded by one microphone only. The goal is to identify both of the speakers from their mixed signal. High recognition accuracies have already been reported when an accurately e...... target speakers enlisted as three and two most probable speakers, respectively....

  17. The changing of the guard: the Pto/Prf receptor complex of tomato and pathogen recognition.

    Science.gov (United States)

    Ntoukakis, Vardis; Saur, Isabel M L; Conlan, Brendon; Rathjen, John P

    2014-08-01

    One important model for disease resistance is the Prf recognition complex of tomato, which responds to different bacterial effectors. Prf incorporates a protein kinase called Pto as its recognition domain that mimics effector virulence targets, and activates resistance after interaction with specific effectors. Recent findings show that this complex is oligomeric, and reveal how this impacts mechanism. Oligomerisation brings two or more kinases into proximity, where they can phosphorylate each other after effector perception. Effector attack on one kinase activates another in trans, constituting a molecular trap for the effector. Oligomerisation of plant resistance proteins may be a general concept that broadens pathogen recognition and restricts the ability of pathogens to evolve virulence.

  18. FPGA-Based Implementation of Lithuanian Isolated Word Recognition Algorithm

    Directory of Open Access Journals (Sweden)

    Tomyslav Sledevič

    2013-05-01

    Full Text Available The paper describes the FPGA-based implementation of Lithuanian isolated word recognition algorithm. FPGA is selected for parallel process implementation using VHDL to ensure fast signal processing at low rate clock signal. Cepstrum analysis was applied to features extraction in voice. The dynamic time warping algorithm was used to compare the vectors of cepstrum coefficients. A library of 100 words features was created and stored in the internal FPGA BRAM memory. Experimental testing with speaker dependent records demonstrated the recognition rate of 94%. The recognition rate of 58% was achieved for speaker-independent records. Calculation of cepstrum coefficients lasted for 8.52 ms at 50 MHz clock, while 100 DTWs took 66.56 ms at 25 MHz clock.Article in Lithuanian

  19. Classification of EEG for Affect Recognition: An Adaptive Approach

    Science.gov (United States)

    Alzoubi, Omar; Calvo, Rafael A.; Stevens, Ronald H.

    Research on affective computing is growing rapidly and new applications are being developed more frequently. They use information about the affective/mental states of users to adapt their interfaces or add new functionalities. Face activity, voice, text physiology and other information about the user are used as input to affect recognition modules, which are built as classification algorithms. Brain EEG signals have rarely been used to build such classifiers due to the lack of a clear theoretical framework. We present here an evaluation of three different classification techniques and their adaptive variations of a 10-class emotion recognition experiment. Our results show that affect recognition from EEG signals might be possible and an adaptive algorithm improves the performance of the classification task.

  20. Sterile-α- and Armadillo Motif-Containing Protein Inhibits the TRIF-Dependent Downregulation of Signal Regulatory Protein α To Interfere with Intracellular Bacterial Elimination in Burkholderia pseudomallei-Infected Mouse Macrophages

    OpenAIRE

    Baral, Pankaj; Utaisincharoen, Pongsak

    2013-01-01

    Burkholderia pseudomallei, the causative agent of melioidosis, evades macrophage killing by suppressing the TRIF-dependent pathway, leading to inhibition of inducible nitric oxide synthase (iNOS) expression. We previously demonstrated that virulent wild-type B. pseudomallei inhibits the TRIF-dependent pathway by upregulating sterile-α- and armadillo motif-containing protein (SARM) and by inhibiting downregulation of signal regulatory protein α (SIRPα); both molecules are negative regulators o...