ComputersProtein Sorting Signals: Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Attitude to Computers: The attitude and behavior associated with an individual using the computer.Computer Peripherals: Various units or machines that operate in combination or in conjunction with a computer but are not physically part of it. Peripheral devices typically display computer data, store data from the computer and return the data to the computer on demand, prepare data for human use, or acquire data from a source and convert it to a form usable by a computer. (Computer Dictionary, 4th ed.)Computer Literacy: Familiarity and comfort in using computers efficiently.Computer Systems: Systems composed of a computer or computers, peripheral equipment, such as disks, printers, and terminals, and telecommunications capabilities.Computers, Handheld: A type of MICROCOMPUTER, sometimes called a personal digital assistant, that is very small and portable and fitting in a hand. They are convenient to use in clinical and other field situations for quick data management. They usually require docking with MICROCOMPUTERS for updates.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Computer User Training: Process of teaching a person to interact and communicate with a computer.Computer Terminals: Input/output devices designed to receive data in an environment associated with the job to be performed, and capable of transmitting entries to, and obtaining output from, the system of which it is a part. (Computer Dictionary, 4th ed.)Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Signal Processing, Computer-Assisted: Computer-assisted processing of electric, ultrasonic, or electronic signals to interpret function and activity.Software: Sequential operating programs and data which instruct the functioning of a digital computer.Computers, Analog: Computers in which quantities are represented by physical variables; problem parameters are translated into equivalent mechanical or electrical circuits as an analog for the physical phenomenon being investigated. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Diagnosis, Computer-Assisted: Application of computer programs designed to assist the physician in solving a diagnostic problem.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Computer Communication Networks: A system containing any combination of computers, computer terminals, printers, audio or visual display devices, or telephones interconnected by telecommunications equipment or cables: used to transmit or receive information. (Random House Unabridged Dictionary, 2d ed)Computer Graphics: The process of pictorial communication, between human and computers, in which the computer input and output have the form of charts, drawings, or other appropriate pictorial representation.Nuclear Localization Signals: Short, predominantly basic amino acid sequences identified as nuclear import signals for some proteins. These sequences are believed to interact with specific receptors at the NUCLEAR PORE.Minicomputers: Small computers that lack the speed, memory capacity, and instructional capability of the full-size computer but usually retain its programmable flexibility. They are larger, faster, and more flexible, powerful, and expensive than microcomputers.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Computer-Assisted Instruction: A self-learning technique, usually online, involving interaction of the student with programmed instructional materials.Image Processing, Computer-Assisted: A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Information Systems: Integrated set of files, procedures, and equipment for the storage, manipulation, and retrieval of information.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Computers, Molecular: Computers whose input, output and state transitions are carried out by biochemical interactions and reactions.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Automatic Data Processing: Data processing largely performed by automatic means.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Neural Networks (Computer): A computer architecture, implementable in either hardware or software, modeled after biological neural networks. Like the biological system in which the processing capability is a result of the interconnection strengths between arrays of nonlinear processing nodes, computerized neural networks, often called perceptrons or multilayer connectionist models, consist of neuron-like units. A homogeneous group of units makes up a layer. These networks are good at pattern recognition. They are adaptive, performing tasks by example, and thus are better for decision-making than are linear learning machines or cluster analysis. They do not require explicit programming.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Data Display: The visual display of data in a man-machine system. An example is when data is called from the computer and transmitted to a CATHODE RAY TUBE DISPLAY or LIQUID CRYSTAL display.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Internet: A loose confederation of computer communication networks around the world. The networks that make up the Internet are connected through several backbone networks. The Internet grew out of the US Government ARPAnet project and was designed to facilitate information exchange.Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Kinetics: The rate dynamics in chemical or physical systems.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Word Processing: Text editing and storage functions using computer software.Medical Records Systems, Computerized: Computer-based systems for input, storage, display, retrieval, and printing of information contained in a patient's medical record.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Video Games: A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Models, Neurological: Theoretical representations that simulate the behavior or activity of the neurological system, processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Computers, Hybrid: Computers that combine the functions of analog and digital computers. (Sippl, Computer Dictionary, 4th ed)DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Bacterial Proteins: Proteins found in any species of bacterium.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Computer Security: Protective measures against unauthorized access to or interference with computer operating systems, telecommunications, or data structures, especially the modification, deletion, destruction, or release of data in computers. It includes methods of forestalling interference by computer viruses or so-called computer hackers aiming to compromise stored data.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Adaptor Proteins, Signal Transducing: A broad category of carrier proteins that play a role in SIGNAL TRANSDUCTION. They generally contain several modular domains, each of which having its own binding activity, and act by forming complexes with other intracellular-signaling molecules. Signal-transducing adaptor proteins lack enzyme activity, however their activity can be modulated by other signal-transducing enzymesTransfection: The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.Signal Detection, Psychological: Psychophysical technique that permits the estimation of the bias of the observer as well as detectability of the signal (i.e., stimulus) in any sensory modality. (From APA, Thesaurus of Psychological Index Terms, 8th ed.)Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Nuclear Export Signals: Specific amino acid sequences present in the primary amino acid sequence of proteins which mediate their export from the CELL NUCLEUS. They are rich in hydrophobic residues, such as LEUCINE and ISOLEUCINE.Therapy, Computer-Assisted: Computer systems utilized as adjuncts in the treatment of disease.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Neurons: The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Gene Expression Regulation: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Surgery, Computer-Assisted: Surgical procedures conducted with the aid of computers. This is most frequently used in orthopedic and laparoscopic surgery for implant placement and instrument guidance. Image-guided surgery interactively combines prior CT scans or MRI images with real-time video.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Human Engineering: The science of designing, building or equipping mechanical devices or artificial environments to the anthropometric, physiological, or psychological requirements of the people who will use them.Cumulative Trauma Disorders: Harmful and painful condition caused by overuse or overexertion of some part of the musculoskeletal system, often resulting from work-related physical activities. It is characterized by inflammation, pain, or dysfunction of the involved joints, bones, ligaments, and nerves.Equipment Design: Methods of creating machines and devices.Animal Communication: Communication between animals involving the giving off by one individual of some chemical or physical signal, that, on being received by another, influences its behavior.Models, Genetic: Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Enzyme Activation: Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.Office Automation: Use of computers or computer systems for doing routine clerical work, e.g., billing, records pertaining to the administration of the office, etc.Photic Stimulation: Investigative technique commonly used during ELECTROENCEPHALOGRAPHY in which a series of bright light flashes or visual patterns are used to elicit brain activity.Calcium Signaling: Signal transduction mechanisms whereby calcium mobilization (from outside the cell or from intracellular storage pools) to the cytoplasm is triggered by external stimuli. Calcium signals are often seen to propagate as waves, oscillations, spikes, sparks, or puffs. The calcium acts as an intracellular messenger by activating calcium-responsive proteins.STAT3 Transcription Factor: A signal transducer and activator of transcription that mediates cellular responses to INTERLEUKIN-6 family members. STAT3 is constitutively activated in a variety of TUMORS and is a major downstream transducer for the CYTOKINE RECEPTOR GP130.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Computer-Aided Design: The use of computers for designing and/or manufacturing of anything, including drugs, surgical procedures, orthotics, and prosthetics.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Online Systems: Systems where the input data enter the computer directly from the point of origin (usually a terminal or workstation) and/or in which output data are transmitted directly to that terminal point of origin. (Sippl, Computer Dictionary, 4th ed)Imaging, Three-Dimensional: The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Computer Storage Devices: Devices capable of receiving data, retaining data for an indefinite or finite period of time, and supplying data upon demand.Models, Cardiovascular: Theoretical representations that simulate the behavior or activity of the cardiovascular system, processes, or phenomena; includes the use of mathematical equations, computers and other electronic equipment.Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Action Potentials: Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.Cell Differentiation: Progressive restriction of the developmental potential and increasing specialization of function that leads to the formation of specialized cells, tissues, and organs.Man-Machine Systems: A system in which the functions of the man and the machine are interrelated and necessary for the operation of the system.DNA, Complementary: Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.Mice, Inbred C57BLGene Expression: The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Artifacts: Any visible result of a procedure which is caused by the procedure itself and not by the entity being analyzed. Common examples include histological structures introduced by tissue processing, radiographic images of structures that are not naturally present in living tissue, and products of chemical reactions that occur during analysis.Hospital Information Systems: Integrated, computer-assisted systems designed to store, manipulate, and retrieve information concerned with the administrative and clinical aspects of providing medical services within the hospital.Mutagenesis, Site-Directed: Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.Protein Processing, Post-Translational: Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.Communication Aids for Disabled: Equipment that provides mentally or physically disabled persons with a means of communication. The aids include display boards, typewriters, cathode ray tubes, computers, and speech synthesizers. The output of such aids includes written words, artificial speech, language signs, Morse code, and pictures.Image Interpretation, Computer-Assisted: Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Ligands: A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Brain-Computer Interfaces: Instrumentation consisting of hardware and software that communicates with the BRAIN. The hardware component of the interface records brain signals, while the software component analyzes the signals and converts them into a command that controls a device or sends a feedback signal to the brain.Databases, Factual: Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Television: The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)COS Cells: CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)Multimedia: Materials, frequently computer applications, that combine some or all of text, sound, graphics, animation, and video into integrated packages. (Thesaurus of ERIC Descriptors, 1994)Green Fluorescent Proteins: Protein analogs and derivatives of the Aequorea victoria green fluorescent protein that emit light (FLUORESCENCE) when excited with ULTRAVIOLET RAYS. They are used in REPORTER GENES in doing GENETIC TECHNIQUES. Numerous mutants have been made to emit other colors or be sensitive to pH.Tyrosine: A non-essential amino acid. In animals it is synthesized from PHENYLALANINE. It is also the precursor of EPINEPHRINE; THYROID HORMONES; and melanin.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Receptors, Cell Surface: Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Image Enhancement: Improvement of the quality of a picture by various techniques, including computer processing, digital filtering, echocardiographic techniques, light and ultrastructural MICROSCOPY, fluorescence spectrometry and microscopy, scintigraphy, and in vitro image processing at the molecular level.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Software Design: Specifications and instructions applied to the software.Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.Mitogen-Activated Protein Kinases: A superfamily of PROTEIN-SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).Monte Carlo Method: In statistics, a technique for numerically approximating the solution of a mathematical problem by studying the distribution of some random variable, often generated by a computer. The name alludes to the randomness characteristic of the games of chance played at the gambling casinos in Monte Carlo. (From Random House Unabridged Dictionary, 2d ed, 1993)Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Automation: Controlled operation of an apparatus, process, or system by mechanical or electronic devices that take the place of human organs of observation, effort, and decision. (From Webster's Collegiate Dictionary, 1993)Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Video Recording: The storing or preserving of video signals for television to be played back later via a transmitter or receiver. Recordings may be made on magnetic tape or discs (VIDEODISC RECORDING).Medical Informatics Applications: Automated systems applied to the patient care process including diagnosis, therapy, and systems of communicating medical data within the health care setting.In Situ Hybridization: A technique that localizes specific nucleic acid sequences within intact chromosomes, eukaryotic cells, or bacterial cells through the use of specific nucleic acid-labeled probes.Medical Informatics: The field of information science concerned with the analysis and dissemination of medical data through the application of computers to various aspects of health care and medicine.Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)HeLa Cells: The first continuously cultured human malignant CELL LINE, derived from the cervical carcinoma of Henrietta Lacks. These cells are used for VIRUS CULTIVATION and antitumor drug screening assays.Ambulatory Care Information Systems: Information systems, usually computer-assisted, designed to store, manipulate, and retrieve information for planning, organizing, directing, and controlling administrative activities associated with the provision and utilization of ambulatory care services and facilities.Information Storage and Retrieval: Organized activities related to the storage, location, search, and retrieval of information.Reaction Time: The time from the onset of a stimulus until a response is observed.Feedback: A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.Musculoskeletal Diseases: Diseases of the muscles and their associated ligaments and other connective tissue and of the bones and cartilage viewed collectively.Brain Mapping: Imaging techniques used to colocalize sites of brain functions or physiological activity with brain structures.Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Enzyme Inhibitors: Compounds or agents that combine with an enzyme in such a manner as to prevent the normal substrate-enzyme combination and the catalytic reaction.Endoplasmic Reticulum: A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)Sequence Homology, Nucleic Acid: The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Evaluation Studies as Topic: Studies determining the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. For drugs and devices, CLINICAL TRIALS AS TOPIC; DRUG EVALUATION; and DRUG EVALUATION, PRECLINICAL are available.Active Transport, Cell Nucleus: Gated transport mechanisms by which proteins or RNA are moved across the NUCLEAR MEMBRANE.Protein Biosynthesis: The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.Cell Line, Tumor: A cell line derived from cultured tumor cells.Nuclear Proteins: Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Electroencephalography: Recording of electric currents developed in the brain by means of electrodes applied to the scalp, to the surface of the brain, or placed within the substance of the brain.Mice, Transgenic: Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.Arabidopsis: A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.Protein PrecursorsMethods: A series of steps taken in order to conduct research.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.PhosphoproteinsMedical Records: Recording of pertinent information concerning patient's illness or illnesses.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Gene Expression Profiling: The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Equipment Failure Analysis: The evaluation of incidents involving the loss of function of a device. These evaluations are used for a variety of purposes such as to determine the failure rates, the causes of failures, costs of failures, and the reliability and maintainability of devices.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Species Specificity: The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.Immunohistochemistry: Histochemical localization of immunoreactive substances using labeled antibodies as reagents.Intracellular Signaling Peptides and Proteins: Proteins and peptides that are involved in SIGNAL TRANSDUCTION within the cell. Included here are peptides and proteins that regulate the activity of TRANSCRIPTION FACTORS and cellular processes in response to signals from CELL SURFACE RECEPTORS. Intracellular signaling peptide and proteins may be part of an enzymatic signaling cascade or act through binding to and modifying the action of other signaling factors.Electronics: The study, control, and application of the conduction of ELECTRICITY through gases or vacuum, or through semiconducting or conducting materials. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Chromosome Mapping: Any method used for determining the location of and relative distances between genes on a chromosome.Computing Methodologies: Computer-assisted analysis and processing of problems in a particular area.RNA: A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. (Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)

Phase reversal of biomechanical functions and muscle activity in backward pedaling. (1/3966)

Computer simulations of pedaling have shown that a wide range of pedaling tasks can be performed if each limb has the capability of executing six biomechanical functions, which are arranged into three pairs of alternating antagonistic functions. An Ext/Flex pair accelerates the limb into extension or flexion, a Plant/Dorsi pair accelerates the foot into plantarflexion or dorsiflexion, and an Ant/Post pair accelerates the foot anteriorly or posteriorly relative to the pelvis. Because each biomechanical function (i.e., Ext, Flex, Plant, Dorsi, Ant, or Post) contributes to crank propulsion during a specific region in the cycle, phasing of a muscle is hypothesized to be a consequence of its ability to contribute to one or more of the biomechanical functions. Analysis of electromyogram (EMG) patterns has shown that this biomechanical framework assists in the interpretation of muscle activity in healthy and hemiparetic subjects during forward pedaling. Simulations show that backward pedaling can be produced with a phase shift of 180 degrees in the Ant/Post pair. No phase shifts in the Ext/Flex and Plant/Dorsi pairs are then necessary. To further test whether this simple yet biomechanically viable strategy may be used by the nervous system, EMGs from 7 muscles in 16 subjects were measured during backward as well as forward pedaling. As predicted, phasing in vastus medialis (VM), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SL) were unaffected by pedaling direction, with VM and SL contributing to Ext, MG to Plant, and TA to Dorsi. In contrast, phasing in biceps femoris (BF) and semimembranosus (SM) were affected by pedaling direction, as predicted, compatible with their contribution to the directionally sensitive Post function. Phasing of rectus femoris (RF) was also affected by pedaling direction; however, its ability to contribute to the directionally sensitive Ant function may only be expressed in forward pedaling. RF also contributed significantly to the directionally insensitive Ext function in both forward and backward pedaling. Other muscles also appear to have contributed to more than one function, which was especially evident in backward pedaling (i.e. , BF, SM, MG, and TA to Flex). We conclude that the phasing of only the Ant and Post biomechanical functions are directionally sensitive. Further, we suggest that task-dependent modulation of the expression of the functions in the motor output provides this biomechanics-based neural control scheme with the capability to execute a variety of lower limb tasks, including walking.  (+info)

Varying the degree of single-whisker stimulation differentially affects phases of intrinsic signals in rat barrel cortex. (2/3966)

Using intrinsic signal optical imaging (ISI), we have shown previously that the point spread of evoked activity in the rat barrel cortex in response to single-whisker stimulation encompasses a surprisingly large area. Given that our typical stimulation consists of five deflections at 5 Hz, the large area of evoked activity might have resulted from repetitive stimulation. Thus in the present study, we use ISI through the thinned skull to determine whether decreasing the degree of single-whisker stimulation decreases the area of the cortical point spread. We additionally outline a protocol to quantify stimulus-related differences in the temporal characteristics of intrinsic signals at a fine spatial scale. In 10 adult rats, whisker C2 was stimulated randomly with either one or five deflections delivered in a rostral-to-caudal fashion. Each deflection consisted of a 0.5-mm displacement of the whisker as measured at the point of contact, 15 mm from the snout. The number of whisker deflections did not affect the area or peak magnitude of the cortical point spread based on the intrinsic signal activity occurring from 0.5 up to 1.5 s poststimulus onset. In contrast, the magnitude and time course of intrinsic signal activity collected after 1.5-s poststimulus onset did reflect the difference in the degree of stimulation. Thus decreasing the degree of stimulation differentially affected the early and late phases of the evoked intrinsic signal response. The implications of the present results are discussed in respect to probable differences in the signal source underlying the early versus later phases of evoked intrinsic signals.  (+info)

A new filtering algorithm for medical magnetic resonance and computer tomography images. (3/3966)

Inner views of tubular structures based on computer tomography (CT) and magnetic resonance (MR) data sets may be created by virtual endoscopy. After a preliminary segmentation procedure for selecting the organ to be represented, the virtual endoscopy is a new postprocessing technique using surface or volume rendering of the data sets. In the case of surface rendering, the segmentation is based on a grey level thresholding technique. To avoid artifacts owing to the noise created in the imaging process, and to restore spurious resolution degradations, a robust Wiener filter was applied. This filter working in Fourier space approximates the noise spectrum by a simple function that is proportional to the square root of the signal amplitude. Thus, only points with tiny amplitudes consisting mostly of noise are suppressed. Further artifacts are avoided by the correct selection of the threshold range. Afterwards, the lumen and the inner walls of the tubular structures are well represented and allow one to distinguish between harmless fluctuations and medically significant structures.  (+info)

Image processing strategies in picture archiving and communication systems. (4/3966)

An image processing strategy is presented that assures very similar soft-copy presentation on diagnostic workstations of a picture archiving and communication system (PACS) over the lifetime of an image file and simultaneously provides efficient work-flow. The strategy is based on rigid partitioning of image processing into application- and display-device-specific processing. Application-specific processing is optimized for a reference display system. A description of this system is attached to the file header of the application-specifically processed image which is stored in the PACS. Every diagnostic display system automatically reproduces the image quality for which the application-specific processing was optimized by adjusting its properties by display-system-specific processing so that the system becomes effectively equal to the reference display system.  (+info)

A new tool for measuring the suckling stimulus during breastfeeding in humans: the orokinetogram and the Fourier series. (5/3966)

The Fourier series was used to analyse the oral movements recorded by the orokinetogram during breastfeeding in human babies. This is a new method that allows recording of oral movements without introducing any extrinsic element between the nipple and the mouth of the baby. The advantage of displaying suckling activity after fast Fourier transform (FFT) is that this algorithm allows storage, quantification and frequency analysis of the oral movements throughout a suckling bout, which enables the total oral activity to be measured. Two types of oral movements are found: slow high amplitude (SHA) and fast low amplitude (FLA). FLA movements may be derived from peristaltic movements of the tongue that result in tickling stimuli to the mechanoreceptors of the nipple and milk expression. The frequency bandwidth of oral movements is wider (0-8 Hz) than has been described previously (0-3 Hz) and this is due to the presence of the FLA oral movements. An indirect measurement of the energy of oral movements during suckling is obtained by the pattern of energy distribution used in each individual frequency band by oral movements. This pattern changes in relation to the periods of continuous and intermittent suckling activity. SHA and FLA oral movements are more intense during continuous suckling. Statistical analysis showed a correlation between the energy of SHA and FLA waves throughout the suckling bout, and also that the highest level of energy during suckling activity is displayed during the first 2 min. The novel tools described in this paper allow investigation of the role of suckling stimulus in reflex hormone release and other mother-infant interactions.  (+info)

Ryanodine and the left ventricular force-interval and relaxation-interval relations in closed-chest dogs: insights on calcium handling. (6/3966)

OBJECTIVE: Although the myocardial force-interval and relaxation-interval relations are considered to be mechanical expressions of myocardial Ca2+ handling, correlation of these phenomena with altered Ca2+ kinetics in the intact state is limited. Thus, I sought to determine the impact of selective impairment of physiologic sarcoplasmic reticulum Ca2+ release, achieved by the use of the drug ryanodine, on these relations in the intact animal. METHODS: Twelve dogs instrumented with left ventricular manometers and piezoelectric dimension crystals were studied before and after ryanodine (4 micrograms/kg intravenously). End-systolic elastance was measured at paced heart rates of 120-180 bpm to determine the force-frequency response. Mechanical restitution and relaxation restitution were determined by measuring contractile (single beat elastance) and relaxation (peak negative dP/dt) responses for beats delivered at graded extrasystolic intervals, with normalized responses expressed as a function of extrasystolic interval. RESULTS: Ryanodine accelerated mechanical restitution (time constant 60.3 +/- 3.9 versus 81.7 +/- 10.1 ms, p < 0.05) and reduced maximal contractile response (107.5 +/- 2.1 versus 122.1 +/- 5.7%, p < 0.05), slowed early relaxation restitution (time constant 65.5 +/- 13.8 versus 36.8 +/- 3.8 ms, p < 0.05) without changing late relaxation restitution kinetics, and amplified the force-frequency response (end-systolic elastance, 180 bpm, 19.4 +/- 4.3 versus 11.4 +/- 1.2 mm Hg/ml, p < 0.05). CONCLUSIONS: These findings suggest that in the intact animal, Ca2+ handling by the sarcoplasmic reticulum is a primary determinant of mechanical restitution and early relaxation restitution, but not late relaxation restitution. Conversely, ryanodine induced augmentation of the force-frequency response indicates a central role for sarcolemmal Ca2+ influx in producing frequency potentiation.  (+info)

Delayed rectifier potassium current in undiseased human ventricular myocytes. (7/3966)

OBJECTIVE: The purpose of the study was to investigate the properties of the delayed rectifier potassium current (IK) in myocytes isolated from undiseased human left ventricles. METHODS: The whole-cell configuration of the patch-clamp technique was applied in 28 left ventricular myocytes from 13 hearts at 35 degrees C. RESULTS: An E-4031 sensitive tail current identified the rapid component of IK (IKr) in the myocytes, but there was no evidence for an E-4031 insensitive slow component of IK (IKs). When nifedipine (5 microM) was used to block the inward calcium current (ICa), IKr activation was fast (tau = 31.0 +/- 7.4 ms, at +30 mV, n = 5) and deactivation kinetics were biexponential and relatively slow (tau 1 = 600.0 +/- 53.9 ms and tau 2 = 6792.2 +/- 875.7 ms, at -40 mV, n = 7). Application of CdCl2 (250 microM) to block ICa altered the voltage dependence of the IKr considerably, slowing its activation (tau = 657.1 +/- 109.1 ms, at +30 mV, n = 5) and accelerating its deactivation (tau = 104.0 +/- 18.5 ms, at -40 mV, n = 8). CONCLUSIONS: In undiseased human ventricle at 35 degrees C IKr exists having fast activation and slow deactivation kinetics; however, there was no evidence found for an expressed IKs. IKr probably plays an important role in the frequency dependent modulation of repolarization in undiseased human ventricle, and is a target for many Class III antiarrhythmic drugs.  (+info)

Neurocardiac and cerebral responses evoked by esophageal vago-afferent stimulation in humans: effect of varying intensities. (8/3966)

OBJECTIVE: This study was designed to determine whether esophageal vago-afferent electrostimulation, over a wide range of stimulus intensities, can sustain a cardiac vago-efferent effect by way of central nervous system processing. METHODS: Studies were performed in ten healthy male subjects (23.9 +/- 6.3 years). Esophageal electrostimulation was carried out using a stimulating electrode placed in the distal esophagus. Stimulation of esophageal vago-afferent fibres was employed using electrical impulses (200 microseconds at 0.2 Hz x 128 s) varying from 2.7 to 20 mA. Respiratory frequencies, beat-to-beat heart rate autospectra and cerebral evoked potentials were recorded at baseline and at each stimulus intensity in random order. RESULTS: With esophageal electrical stimulation, we observed a small non-significant decrease in heart rate. There was a dramatic shift of the instantaneous heart rate power spectra towards enhanced cardiac vagal modulation with intensities as low as 5 mA. This effect was sustained throughout all intensities with no further change in either the low frequency or high frequency power. Conversely, there was a linear dose response relationship between cerebral evoked potential amplitude and stimulus intensity mainly occurring above perception threshold (10 mA). Esophageal stimulation had no significant effect on heart rate or respiratory frequency at any stimulus intensity. CONCLUSIONS: These results indicate that electrical stimulation of the distal esophagus across a wide range of current intensities elicits a reproducible shift in the heart rate power spectrum towards enhanced vagal modulation. The data suggest a closed loop afferent/efferent circuitry wherein tonic visceral afferent impulses appear to elicit a phasic or modulatory vago-efferent cardiac response in healthy subjects.  (+info)

  • Compared with the BOLD signal, the CBV signal provides higher reproducibility and better spatial resolvability for function mapping of LGN because of improved contrast-to-noise ratio and point-spread function. (umassmed.edu)
  • A new database of cardiovascular signals has recently been developed at the CNR Institute of Clinical Physiology in a study based on patients admitted to the Coronary Care Unit for suspected ischaemic heart disease (IHD), who underwent both ECG effort stress test and echo or radionuclide diagnostic imaging procedures associated with pharmacological test of myocardial ischaemia. (biomedsearch.com)
  • Containing over 1400 references and mathematical expressions Adaptive Blind Signal and Image Processing delivers an unprecedented collection of useful techniques for adaptive blind signal/image separation, extraction, decomposition and filtering of multi-variable signals and data. (eurobuch.com)
  • As a result, the way in which we visualize the white matter tracts can be very different based on the different mathematical equations used in the process of modeling. (jefferson.edu)
  • Aubert, G., Kornprobst, P.: Mathematical Problems in Image Processing: Partial Differential Equations and the Calculus of Variations. (springer.com)
  • The involvement and the regulation of the ion channels involved in mediating ion fluxes during an AP will be intensively investigated, resulting finally in a mathematical model of electrical signalling in plants. (europa.eu)
  • The proposal will bring together three groups with expertise in (i) molecular electrophysiology of plant ion channels, (ii) electrophysiology, especially in relation to electrical signalling and (iii) computer-assisted mathematical modelling of plant biological processes, along with a returning European electrophysiologist with expertise in ion transport. (europa.eu)
  • S. Saki, A. Bhattacharya, and N. Kehtarnavaz, Real-time Simulink implementation of noise adaptive speech processing pipeline of cochlear implants, to appear in Speech Communication Journal, 2018. (utdallas.edu)
  • C-H. Chang and N. Kehtarnavaz, A computationally efficient pipeline for 3D point cloud reconstruction from video sequences, to appear in Proceedings of SPIE Conference on Real-Time Image and Video Processing, April 2018. (utdallas.edu)
  • F. Saki and N. Kehtarnavaz, Real-time hierarchical classification of sounds signals for hearing improvement devices, to appear in Applied Acoustics Journal, vol. 132, pp. 26-32, March 2018. (utdallas.edu)
  • A method for assisting in the diagnosis of heart murmurs. (google.com)
  • Dr. El-Baz is an expert in the fields of bioimaging modeling and computer assisted diagnosis systems. (ebooks.com)
  • Since its establishment in 1972, the IBM Haifa Research Lab described itself as trying to be responsive to both the research goals of IBM and the specific needs of Israeli industry - from medical non-invasive diagnosis projects, to computer-controlled irrigation, scheduling El Al flight crews, and Hebrew voice recognition. (wikipedia.org)
  • Imaging-documented cardiovascular signal database for assessing methods for ischaemia analysis. (biomedsearch.com)
  • Evaluating methods for computer-assisted stemmatology using artificial benchmark data sets. (helsinki.fi)
  • A class of contemporary methods of sound synthesis and signal processing known as time-frequency models that emerged over the last two decades has their basis at this quantum level such that changes in a signal's time domain result in spectral alterations and vice versa. (sfu.ca)
  • We describe a new approach, the constrained adaptive beamformer (CAB), which builds on classic array processing methods. (spie.org)
  • The aim of the present work was to use two methods working in the time domain, an independent component analysis algorithm (FastICA) and an adaptive maternal beat subtraction technique (AMBS), for the retrieval of fetal cardiac signals from fMCGs. (ox.ac.uk)
  • Depicting several applications of different methods to analyze NLO signals. (intechopen.com)
  • The study is based on EEG signals from six full term infants who have suffered from perinatal asphyxia, and the methods have been trained with reference data classified by an experienced electroencephalographer. (chalmers.se)
  • A key challenge in machine learning ap proaches for epilepsy research is the lack of a data resource of analysis-ready (no additional preprocessing is needed when using the data for developing computational methods) seizure signal datasets with associated tools for seizure data management and visualization. (cdc.gov)
  • The present invention concerns computer assisted detection of heart sounds and, in particular, the detection of systolic murmurs. (google.com)
  • Ding Q, Bai Y, Erol YB, Salas-Boni R, Zhang X, Hu X. Robust QRS peak detection by multimodal information fusion of ECG and blood pressure signals. (ucsf.edu)
  • A number of different sensor systems are exemplified, leak detection systems, liquid sensing, the Biacore instrument, glucose sensors, computer screen assisted technology. (liu.se)
  • I engineered autonomous and programmable biosensors integrating multiplexed pathological biomarker detection and complex biological signal processing as intelligent diagnostic devices. (openwetware.org)
  • N. Dawar and N. Kehtarnavaz, Continuous detection and recognition of actions of interest among actions of non-interest using a depth camera, Proceedings of IEEE International Conference on Image Processing, Beijing, China, September 2017. (utdallas.edu)
  • N. Dawar, C. Chen, R. Jafari, and N. Kehtarnavaz, Real-time continuous action detection and recognition using depth images and inertial signals, Proceedings of IEEE International Symposium on Industrial Electronics, Edinburgh, Scotland, June 2017. (utdallas.edu)
  • A system for biosignal based device applications contains a biosignal sensor (e.g. biosensor) or multiple biosensors (e.g. multiple biosensors for EEG detection, or multiple biosensors that can each detect different types of biosignals), a biosignal processing unit, the apparatus (hardware), and a software application(s) that operate the biosignal information for different applications [ 6 ]. (alliedacademies.org)
  • In this paper, we study a "semiautomatic" method for AEA-waves detection using a linear combination of 12-lead ECG signals. (bgu.ac.il)
  • To examine the effect of noise on coherence estimation, we systematically varied the noise by changing its variance relative to the signal and estimated the coherence between channel X and Z in the above simulation. (nih.gov)
  • While the amount of noise derived from this particular simulation is empirical, it indicates that the amount of noise should be four orders of magnitude less than the signal. (nih.gov)
  • The U.S. Defense Department is developing a new simulation environment to provide readily available, operationally valid, computer-assisted instruction for commanders in chief. (afcea.org)
  • Known as the joint simulation system, the assemblage will train the commanders, their components and commands, other joint organizations, and the services and agencies in computer-assisted joint exercises. (afcea.org)
  • The joint simulation system, or JSIMS, is a single, seamlessly integrated joint synthetic battlespace that provides a common environmental and operational picture of the battle area, an effective combat adjudication process, and a robust after-action review capability. (afcea.org)
  • At maturity, the technology will allow globally dispersed forces-including deployed U.S. forces, research and development test facilities and ranges, defense educational institutions, Reserve components, U.S. government agencies, allies and multinational forces-to participate simultaneously in multiechelon, simulation-assisted training events. (afcea.org)
  • For the preoperative planning, a computer simulation was developed that allows the quantification of the malunion by comparing the 3-d surface model of the impaired bone with the contralateral anatomy. (jove.com)
  • Noise-assisted instantaneous coherence analysis of brain connectivity. (nih.gov)
  • Characterizing brain connectivity between neural signals is key to understanding brain function.In our method, fully data-driven MEMD, together with Hilbert transform, is first employed to provide time-frequency power spectra for neural data.Furthermore, a statistical randomization procedure is designed to cancel out the effect of the added noise. (nih.gov)
  • Characterizing brain connectivity between neural signals is key to understanding brain function. (nih.gov)
  • Brain-computer interfaces ( BCI ) or brain-neural computer interfaces ( BNCI ) are technologies used in successful science-fiction movies in the past. (europa.eu)
  • patients in locked-in state can paint without any muscular activity, solely by having their brain signals processed. (europa.eu)
  • Via a BNCI , the sensor system (a cap with sensors that you wear on your head) detects your brain activity and transmits your brain signals via the internet to the avatar, which then acts according to your orders . (europa.eu)
  • Intel also will demonstrate a computer that is able to recognize and respond to brain waves when a user thinks about controlling a particular device. (acm.org)
  • files of the database) include at least 3 EEG channels (F3 or F4, C3 or C4 and O1 or O2, referred to A1 or A2), EOG (2 channels), EMG of the submentalis muscle, bilateral anterior tibial EMG, respiration signals (airflow, abdominal and thoracic effort and SaO2) and EKG. (physionet.org)
  • Research in Electrical and Computer Engineering Publications falls into eight broad and interlaced areas. (uwo.ca)
  • In this sense, screening seeks to help in cancer diagnostic process before symptoms became evident in a person, different imaging techniques are employed for this purpose (Mammography, Ultrasonography, X-ray, Magnetic Resonance, etc). (docme.ru)
  • During the diagnostic process many features should be taken into consideration, such as regularity and atrial activity. (bgu.ac.il)
  • 3. The system according to claim 1, wherein said portable control means is comprised of a diagnostic tool which includes a portable housing, an off-board computer circuit contained in said portable housing, and a plug-in memory module which is removably secured to said portable housing, said plug-in memory module having non-volatile memory chip means connected to said off-board computer circuit for storing said new computer code. (google.ca)
  • Prof. Mirmehdi has been involved in computer vision research for 22 years, particularly in the areas of medical imaging, quality inspection, and scene understanding. (ebooks.com)
  • Organizing Committee Member , BAMBI 2015 , Workshop on Bayesian and grAphical Models for Biomedical Imaging, October 9, 2015, in conjunction with the International Conference on Medical Image Computing and Computer Assisted Intervention, Munich, Germany, October 5-9, 2015. (ust.hk)
  • This link will be achieved by means of a hardware/software architecture based on (a) a network of different wearable distributed interfaces working in synergy, orchestrated by an (b) adaptive controller that interprets and fuses bio-signals and hand sensor signals exchanging therefore action and perception information between the HAD and the patient. (europa.eu)
  • Time course reconstruction of fetal cardiac signals from fMCG: independent component analysis versus adaptive maternal beat subtraction. (ox.ac.uk)
  • Neuronal loss and dopamine depletion alters motor signal processing and propagation between the cortical motor areas, the basal ganglia and the thalamus resulting in the motor manifestation of Parkinson's disease (PD). (jefferson.edu)
  • In this pilot study, 224 seizures from 115 patients were extracted from over one terabyte of signal data and deposited in SeizureBank. (cdc.gov)
  • The DTI-data obtained were processed using a FDA approved surgical navigation system program which uses a straightforward fiber-tracking approach known as fiber assignment by continuous tracking (FACT). (jove.com)
  • Computer translators such as Babelfish and Google Translate work best when they have a lot of translation data to work from, says University of Maryland professor Philip Resnik. (acm.org)
  • Neurosciences -- Data processing. (utm.my)
  • SeizureBank comes with a built-in seizure data preparation pipeline and web-based interfaces for querying, exporting and visualizing seizure-related signal data. (cdc.gov)
  • signal transfer means for providing a communication link between said portable control means and said on-board vehicle computer circuit, said signal transfer means including a common data communication path for transmitting said sequence of command signals and said software signals which represent said new computer program code. (google.ca)
  • Keywords Image guidance · Laparoscopic liver surgery · Global registration · Shape matching · Surface descriptors · Computer-assisted surgery Introduction tion, constrained vantage point, limited field of view, poor haptic feedback and occluded anatomy . (deepdyve.com)
  • Image guidance Minimally invasive surgery offers the patient major bene- aims to assist the clinicians in localising and tracking sub- fits over open surgery, including less trauma, less pain and surface structures such as abnormalities or major vessel trees. (deepdyve.com)
  • 4. The model generator system according to claim 1, wherein the object is a bone element and the model generator system is used in computer-assisted surgery. (google.co.uk)
  • Therefore, we would like to build a computer-assisted language learning system that could simultaneously detect pronunciation errors, speech prosody deviations and dialogue act mistakes. (google.com)
  • 7. The model generator system according to claim 4, wherein the surface digitizing tool is used with a bone element having a generally semi-spherical shape, and the processing unit has a center calculator for receiving the model of the selected surface of the bone element and determining a center of the bone element from said model. (google.co.uk)
  • Computer-assisted microsurgery equipment, of the type including an articulated tool support, with one of the ends being integral with a fixed reference system Rc. (google.com)
  • The computer supplies a signal for displaying the position of the tool in the image reference system R i on a monitor and for controlling the position and shifting of said tool as a function of the control signals from the control unit. (google.com)
  • The system will improve efficiency by incorporating tools and automated routines that facilitate responsive design, planning, preparation processes for training events, event execution, and a timely and relevant after-action review. (afcea.org)
  • The first and second semesters form a self-contained Postgraduate Diploma course which provides the necessary music, video, computational and technological skills to allow creative individuals to engage in computer-assisted audio-visual composition and production, engage in audio signal processing system design, apply software tools for the music and media industries and/or enter the arena of media production. (tcd.ie)
  • It has a telemonitoring and home support system to allow and assist BNCI home use. (europa.eu)
  • The CMR paradigm led hearing scientists to view the auditory periphery as a multi-channel signal processing system ultimately impacting the development of processing strategies for hearing aids and cochlear implants. (audiology.org)
  • 2 College of Computer Science and Information System, Najran University, Kingdom of Saudi Arabia. (alliedacademies.org)
  • The review focused on 36 consolidated studies that were found using the following keywords: rehabilitation system, sensor, and computer. (alliedacademies.org)
  • A system and method for reprogramming a non-volatile memory of one or more on-board vehicle computers through a serial communication link between an off-board controller and the on-board vehicle computer. (google.ca)
  • 2. The system according to claim 1, wherein said reprogramming signals include a set of predetermined command signals including a first predetermined command signal for causing the erasure of at least a portion of the existing contents of said non-volatile memory prior to the transmission of said software signals to said on-board vehicle computer circuit. (google.ca)
  • 4. The system according to claim 1, wherein said non-volatile memory of said on-board vehicle computer circuit comprises at least one flash memory chip. (google.ca)
  • 5. The system according to claim 2, wherein said system includes switchable regulator circuit means for causing a selective one of said sequence of command signals to have a voltage level which exceeds any of the power supply voltage levels available on-board a vehicle. (google.ca)
  • 6. The system according to claim 5, wherein said switchable regulator circuit means is contained in an adapter which forms part of said signal transfer means. (google.ca)
  • 7. The system according to claim 6, wherein said voltage level of said selective one of said sequence of command signals exceeds fifteen volts. (google.ca)
  • 8. The system according to claim 1, wherein said interface means includes threshold circuit means for detecting at least one of said sequence of command signals and transmitting an unlocking signal to said non-volatile memory. (google.ca)
  • Biostatistical Analysis and Wavelet Analysis are widely utilized in various fields such as image processing, statistical learning, medical informatics, and so on. (wikicfp.com)
  • An Analysis of the Heterogeneity and IP Packet Reordering Over Multiple Wireless Networks In IEEE Symposium on Computers and Communications (ISCC) . (simula.no)
  • A Robust Model-Based Approach to Indoor Positioning Using Signal Strength In IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) , Edited by P. Friedel , H. Aghvami , M. Dohler and A. Sibille . (simula.no)
  • N. Alamdari, F. Saki, A. Sehgal, and N. Kehtarnavaz, An unsupervised noise classification smartphone app for hearing improvement devices, to appear in Proceedings of IEEE Signal Processing in Medicine and Biology Symposium, Dec 2017. (utdallas.edu)
  • At the IBM Haifa Research Lab, 25% of the technical staff have doctoral degrees in computer science, electrical engineering, mathematics, or related fields. (wikipedia.org)
  • citation needed] Using the Technion's computing facilities, the Center embarked on projects in the fields of medicine, agriculture, economics, computer sciences, and applied mathematics in computer applications. (wikipedia.org)