WorldWideScience

Sample records for artificial processivity clamp

  1. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  2. Curvature-electric effects in artificial and natural membranes studied using patch-clamp techniques.

    Science.gov (United States)

    Petrov, A G; Ramsey, R L; Usherwood, P N

    1989-01-01

    Methods for applying sound pressure to membrane patches formed at the tips of patch-clamp pipettes have been developed. Artificial membrane patches were formed from diphytanoyl phosphatidylcholine using a pipette dipping technique. Natural membrane patches were excised (inside-out mode) from collagenase-treated locust muscle membrane. Curvature-electric signals were registered under both voltage clamp and current clamp conditions. The phenomenon of flexoelectricity in membranes has previously been attributed to curvature-induced polarization originating from the liquid crystalline properties of membranes. The estimated magnitude (2 x 10(-18) C) of the flexoelectric coefficient of the artificial lipid bilayers is consistent with previous findings while that of the muscle membrane was in certain cases several times larger. The present study is the first to report on flexoelectricity in a natural membrane and raises the question of the biological significance of this phenomenon.

  3. Artificial neural networks based controller for glucose monitoring during clamp test.

    Directory of Open Access Journals (Sweden)

    Merav Catalogna

    Full Text Available Insulin resistance (IR is one of the most widespread health problems in modern times. The gold standard for quantification of IR is the hyperinsulinemic-euglycemic glucose clamp technique. During the test, a regulated glucose infusion is delivered intravenously to maintain a constant blood glucose concentration. Current control algorithms for regulating this glucose infusion are based on feedback control. These models require frequent sampling of blood, and can only partly capture the complexity associated with regulation of glucose. Here we present an improved clamp control algorithm which is motivated by the stochastic nature of glucose kinetics, while using the minimal need in blood samples required for evaluation of IR. A glucose pump control algorithm, based on artificial neural networks model was developed. The system was trained with a data base collected from 62 rat model experiments, using a back-propagation Levenberg-Marquardt optimization. Genetic algorithm was used to optimize network topology and learning features. The predictive value of the proposed algorithm during the temporal period of interest was significantly improved relative to a feedback control applied at an equivalent low sampling interval. Robustness to noise analysis demonstrates the applicability of the algorithm in realistic situations.

  4. Replication Clamps and Clamp Loaders

    Science.gov (United States)

    Hedglin, Mark; Kumar, Ravindra; Benkovic, Stephen J.

    2013-01-01

    To achieve the high degree of processivity required for DNA replication, DNA polymerases associate with ring-shaped sliding clamps that encircle the template DNA and slide freely along it. The closed circular structure of sliding clamps necessitates an enzyme-catalyzed mechanism, which not only opens them for assembly and closes them around DNA, but specifically targets them to sites where DNA synthesis is initiated and orients them correctly for replication. Such a feat is performed by multisubunit complexes known as clamp loaders, which use ATP to open sliding clamp rings and place them around the 3′ end of primer–template (PT) junctions. Here we discuss the structure and composition of sliding clamps and clamp loaders from the three domains of life as well as T4 bacteriophage, and provide our current understanding of the clamp-loading process. PMID:23545418

  5. Escherichia coli processivity clamp β from DNA polymerase III is dynamic in solution†

    Science.gov (United States)

    Fang, Jing; Engen, John R.; Beuning, Penny J.

    2011-01-01

    Escherichia coli DNA polymerase III is a highly processive replicase due to the presence of the β clamp protein that tethers DNA polymerases to DNA. The β clamp is a head-to-tail ring-shaped homodimer, in which each protomer contains three structurally similar domains. Although multiple studies have probed the functions of the β clamp, a detailed understanding of the conformational dynamics of the β clamp in solution is lacking. Here we used hydrogen exchange mass spectrometry to characterize the conformation and dynamics of the intact dimer β clamp and a variant form (I272A/L273A) with diminished ability to dimerize in solution. Our data indicate that the β clamp is not a static closed ring but rather is dynamic in solution. The three domains showed different dynamics though they share a highly similar tertiary structure. Domain I, which controls the opening of the clamp by dissociating from Domain III, contained several highly flexible peptides that underwent partial cooperative unfolding (EX1 kinetics) with a half-life ~4 h. The comparison between the β monomer variant and the wild-type β clamp showed that the β monomer was more dynamic. In the monomer, partial unfolding was much faster and additional regions of Domain III also underwent partial unfolding with a half-life ~1 h. Our results suggest that the δ subunit of the clamp loader may function as a “ring holder” to stabilize the transient opening of the β clamp, rather than as a “ring opener”. PMID:21657794

  6. Mechanism of opening a sliding clamp

    OpenAIRE

    Douma, Lauren G.; Yu, Kevin K.; England, Jennifer K.; Levitus, Marcia; Bloom, Linda B.

    2017-01-01

    Abstract Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli β-sliding clamp that destabilize t...

  7. Artificial intelligence and process management

    International Nuclear Information System (INIS)

    Epton, J.B.A.

    1989-01-01

    Techniques derived from work in artificial intelligence over the past few decades are beginning to change the approach in applying computers to process management. To explore this new approach and gain real practical experience of its potential a programme of experimental applications was initiated by Sira in collaboration with the process industry. This programme encompassed a family of experimental applications ranging from process monitoring, through supervisory control and troubleshooting to planning and scheduling. The experience gained has led to a number of conclusions regarding the present level of maturity of the technology, the potential for further developments and the measures required to secure the levels of system integrity necessary in on-line applications to critical processes. (author)

  8. CLAMP - a toolkit for efficiently building customized clinical natural language processing pipelines.

    Science.gov (United States)

    Soysal, Ergin; Wang, Jingqi; Jiang, Min; Wu, Yonghui; Pakhomov, Serguei; Liu, Hongfang; Xu, Hua

    2017-11-24

    Existing general clinical natural language processing (NLP) systems such as MetaMap and Clinical Text Analysis and Knowledge Extraction System have been successfully applied to information extraction from clinical text. However, end users often have to customize existing systems for their individual tasks, which can require substantial NLP skills. Here we present CLAMP (Clinical Language Annotation, Modeling, and Processing), a newly developed clinical NLP toolkit that provides not only state-of-the-art NLP components, but also a user-friendly graphic user interface that can help users quickly build customized NLP pipelines for their individual applications. Our evaluation shows that the CLAMP default pipeline achieved good performance on named entity recognition and concept encoding. We also demonstrate the efficiency of the CLAMP graphic user interface in building customized, high-performance NLP pipelines with 2 use cases, extracting smoking status and lab test values. CLAMP is publicly available for research use, and we believe it is a unique asset for the clinical NLP community. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Post clamp

    Science.gov (United States)

    Ramsey, John K. (Inventor); Meyn, Erwin H. (Inventor)

    1990-01-01

    A pair of spaced collars are mounted at right angles on a clamp body by retaining rings which enable the collars to rotate with respect to the clamp body. Mounting posts extend through aligned holes in the collars and clamp body. Each collar can be clamped onto the inserted post while the clamp body remains free to rotate about the post and collar. The clamp body is selectively clamped onto each post.

  10. Accuracy and Time Delay of Glucose Measurements of Continuous Glucose Monitoring and Bedside Artificial Pancreas During Hyperglycemic and Euglycemic Hyperinsulinemic Glucose Clamp Study.

    Science.gov (United States)

    Kuroda, Akio; Taniguchi, Satoshi; Akehi, Yuko; Mori, Hiroyasu; Tamaki, Motoyuki; Suzuki, Reiko; Otsuka, Yinhua; Matsuhisa, Munehide

    2017-11-01

    Glucose values of continuous glucose monitoring (CGM) have time delays compared with plasma glucose (PG) values. The artificial pancreas (STG-55, Nikkiso, Japan) (AP), which measures venous blood glucose directly, also has a time delay because of the long tubing lines from sampling vessel to the glucose sensor. We investigate accuracy and time delay of CGM and AP in comparison with PG values during 2-step glucose clamp study. Seven patients with type 2 diabetes and 2 healthy volunteers were included in this study. CGM (Enlite sensor, Medtronic, Northridge, CA, USA) was attached on the day before the experiment. Hyperglycemic (200 mg/dL) clamp was performed for 90 minutes, followed by euglycemic (100 mg/dL) hyperinsulinemic (100 μU/mL) clamp for 90-120 minutes using AP. CGM sensor glucose was calibrated just before and after the clamp study. AP and CGM values were compared with PG values. AP values were significantly lower than PG values at 5, 30 minute during hyperglycemic clamp. In comparison, CGM value at 0 minute was significantly higher, and its following values were almost significantly lower than PG values. The time delay of AP and CGM values to reach maximum glucose levels were 5.0 ± 22.3 (NS) and 28.6 ± 32.5 ( P < .05) min, respectively. Mean absolute rate difference of CGM was significantly higher than AP (24.0 ± 7.6 vs 15.3 ± 4.6, P < .05) during glucose rising period (0-45 min); however, there were no significant differences during other periods. Both CGM and AP failed to follow plasma glucose values during nonphysiologically rapid glucose rising, but indicated accurate values during physiological glucose change.

  11. Mechanism of opening a sliding clamp.

    Science.gov (United States)

    Douma, Lauren G; Yu, Kevin K; England, Jennifer K; Levitus, Marcia; Bloom, Linda B

    2017-09-29

    Clamp loaders load ring-shaped sliding clamps onto DNA where the clamps serve as processivity factors for DNA polymerases. In the first stage of clamp loading, clamp loaders bind and stabilize clamps in an open conformation, and in the second stage, clamp loaders place the open clamps around DNA so that the clamps encircle DNA. Here, the mechanism of the initial clamp opening stage is investigated. Mutations were introduced into the Escherichia coli β-sliding clamp that destabilize the dimer interface to determine whether the formation of an open clamp loader-clamp complex is dependent on spontaneous clamp opening events. In other work, we showed that mutation of a positively charged Arg residue at the β-dimer interface and high NaCl concentrations destabilize the clamp, but neither facilitates the formation of an open clamp loader-clamp complex in experiments presented here. Clamp opening reactions could be fit to a minimal three-step 'bind-open-lock' model in which the clamp loader binds a closed clamp, the clamp opens, and subsequent conformational rearrangements 'lock' the clamp loader-clamp complex in a stable open conformation. Our results support a model in which the E. coli clamp loader actively opens the β-sliding clamp. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  12. How a DNA polymerase clamp loader opens a sliding clamp

    OpenAIRE

    Kelch, Brian A.; Makino, Debora L.; O’Donnell, Mike; Kuriyan, John

    2011-01-01

    Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of ATPases. We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the open clamp so that both the loader and the clamp match the helical symmetry of DNA. One structure reveals that ATP has been hydroly...

  13. The Escherichia coli Clamp Loader Can Actively Pry Open the β-Sliding Clamp*

    Science.gov (United States)

    Paschall, Christopher O.; Thompson, Jennifer A.; Marzahn, Melissa R.; Chiraniya, Ankita; Hayner, Jaclyn N.; O'Donnell, Mike; Robbins, Arthur H.; McKenna, Robert; Bloom, Linda B.

    2011-01-01

    Clamp loaders load ring-shaped sliding clamps onto DNA. Once loaded onto DNA, sliding clamps bind to DNA polymerases to increase the processivity of DNA synthesis. To load clamps onto DNA, an open clamp loader-clamp complex must form. An unresolved question is whether clamp loaders capture clamps that have transiently opened or whether clamp loaders bind closed clamps and actively open clamps. A simple fluorescence-based clamp opening assay was developed to address this question and to determine how ATP binding contributes to clamp opening. A direct comparison of real time binding and opening reactions revealed that the Escherichia coli γ complex binds β first and then opens the clamp. Mutation of conserved “arginine fingers” in the γ complex that interact with bound ATP decreased clamp opening activity showing that arginine fingers make an important contribution to the ATP-induced conformational changes that allow the clamp loader to pry open the clamp. PMID:21971175

  14. How a DNA polymerase clamp loader opens a sliding clamp

    Science.gov (United States)

    Kelch, Brian A.; Makino, Debora L.; O’Donnell, Mike; Kuriyan, John

    2012-01-01

    Processive chromosomal replication relies on sliding DNA clamps, which are loaded onto DNA by pentameric clamp loader complexes belonging to the AAA+ family of ATPases. We present structures for the ATP-bound state of the clamp loader complex from bacteriophage T4, bound to an open clamp and primer-template DNA. The clamp loader traps a spiral conformation of the open clamp so that both the loader and the clamp match the helical symmetry of DNA. One structure reveals that ATP has been hydrolyzed in one subunit, and suggests that clamp closure and ejection of the loader involves disruption of the ATP-dependent match in symmetry. The structures explain how synergy between the loader, the clamp and DNA can trigger ATP hydrolysis and release of the closed clamp on DNA. PMID:22194570

  15. Parallel processing for artificial intelligence 1

    CERN Document Server

    Kanal, LN; Kumar, V; Suttner, CB

    1994-01-01

    Parallel processing for AI problems is of great current interest because of its potential for alleviating the computational demands of AI procedures. The articles in this book consider parallel processing for problems in several areas of artificial intelligence: image processing, knowledge representation in semantic networks, production rules, mechanization of logic, constraint satisfaction, parsing of natural language, data filtering and data mining. The publication is divided into six sections. The first addresses parallel computing for processing and understanding images. The second discus

  16. Rigid clamp

    Science.gov (United States)

    Benavides, Gilbert L.; Burt, Jack D.

    1994-01-01

    The invention relates to a clamp mechanism that can be used to attach or temporarily support objects inside of tubular goods. The clamp mechanism can also be modified so that it grips objects. The clamp has a self-centering feature to accommodate out-of-roundness or other internal defections in tubular objects such as pipe. A plurality of clamping shoes are expanded by a linkage which is preferably powered by a motor to contact the inside of a pipe. The motion can be reversed and jaw elements can be connected to the linkage so as to bring the jaws together to grab an object.

  17. Artificial intelligence applied to process signal analysis

    Science.gov (United States)

    Corsberg, Dan

    1988-01-01

    Many space station processes are highly complex systems subject to sudden, major transients. In any complex process control system, a critical aspect of the human/machine interface is the analysis and display of process information. Human operators can be overwhelmed by large clusters of alarms that inhibit their ability to diagnose and respond to a disturbance. Using artificial intelligence techniques and a knowledge base approach to this problem, the power of the computer can be used to filter and analyze plant sensor data. This will provide operators with a better description of the process state. Once a process state is recognized, automatic action could be initiated and proper system response monitored.

  18. Parallel processing for artificial intelligence 2

    CERN Document Server

    Kumar, V; Suttner, CB

    1994-01-01

    With the increasing availability of parallel machines and the raising of interest in large scale and real world applications, research on parallel processing for Artificial Intelligence (AI) is gaining greater importance in the computer science environment. Many applications have been implemented and delivered but the field is still considered to be in its infancy. This book assembles diverse aspects of research in the area, providing an overview of the current state of technology. It also aims to promote further growth across the discipline. Contributions have been grouped according to their

  19. Markov decision processes in artificial intelligence

    CERN Document Server

    Sigaud, Olivier

    2013-01-01

    Markov Decision Processes (MDPs) are a mathematical framework for modeling sequential decision problems under uncertainty as well as Reinforcement Learning problems. Written by experts in the field, this book provides a global view of current research using MDPs in Artificial Intelligence. It starts with an introductory presentation of the fundamental aspects of MDPs (planning in MDPs, Reinforcement Learning, Partially Observable MDPs, Markov games and the use of non-classical criteria). Then it presents more advanced research trends in the domain and gives some concrete examples using illustr

  20. Application of artificial intelligence in process control

    CERN Document Server

    Krijgsman, A

    1993-01-01

    This book is the result of a united effort of six European universities to create an overall course on the appplication of artificial intelligence (AI) in process control. The book includes an introduction to key areas including; knowledge representation, expert, logic, fuzzy logic, neural network, and object oriented-based approaches in AI. Part two covers the application to control engineering, part three: Real-Time Issues, part four: CAD Systems and Expert Systems, part five: Intelligent Control and part six: Supervisory Control, Monitoring and Optimization.

  1. Cell-Detection Technique for Automated Patch Clamping

    Science.gov (United States)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    data are analyzed by software that implements the present machine-vision technique. This analysis results in the identification of cells that are "good" candidates for patch clamping (see figure). Once a "good" cell is identified, a patch clamp can be effected by an automated patchclamping apparatus or by a human operator. This technique has been shown to enable reliable identification of "good" and "bad" candidate cells for patch clamping. The ultimate goal in further development of this technique is to combine artificial-intelligence processing with instrumentation and controls in order to produce a complete "turnkey" automated patch-clamping system capable of accurately and reliably patch clamping cells with a minimum intervention by a human operator. Moreover, this technique can be adapted to virtually any cellular-analysis procedure that includes repetitive operation of microscope hardware by a human.

  2. Charlie's Clamp.

    Science.gov (United States)

    Tarino, Janet Z.

    1998-01-01

    Presents a version of the crush-the-can demonstration which is a hands-on activity in which students use an inexpensive, easily made holder for the can called Charlie's clamp. Includes some suggestions for the follow-up discussion. (DDR)

  3. Artificial intelligence in the materials processing laboratory

    Science.gov (United States)

    Workman, Gary L.; Kaukler, William F.

    1990-01-01

    Materials science and engineering provides a vast arena for applications of artificial intelligence. Advanced materials research is an area in which challenging requirements confront the researcher, from the drawing board through production and into service. Advanced techniques results in the development of new materials for specialized applications. Hand-in-hand with these new materials are also requirements for state-of-the-art inspection methods to determine the integrity or fitness for service of structures fabricated from these materials. Two problems of current interest to the Materials Processing Laboratory at UAH are an expert system to assist in eddy current inspection of graphite epoxy components for aerospace and an expert system to assist in the design of superalloys for high temperature applications. Each project requires a different approach to reach the defined goals. Results to date are described for the eddy current analysis, but only the original concepts and approaches considered are given for the expert system to design superalloys.

  4. Using artificial intelligence to automate remittance processing.

    Science.gov (United States)

    Adams, W T; Snow, G M; Helmick, P M

    1998-06-01

    The consolidated business office of the Allegheny Health Education Research Foundation (AHERF), a large integrated healthcare system based in Pittsburgh, Pennsylvania, sought to improve its cash-related business office activities by implementing an automated remittance processing system that uses artificial intelligence. The goal was to create a completely automated system whereby all monies it processed would be tracked, automatically posted, analyzed, monitored, controlled, and reconciled through a central database. Using a phased approach, the automated payment system has become the central repository for all of the remittances for seven of the hospitals in the AHERF system and has allowed for the complete integration of these hospitals' existing billing systems, document imaging system, and intranet, as well as the new automated payment posting, and electronic cash tracking and reconciling systems. For such new technology, which is designed to bring about major change, factors contributing to the project's success were adequate planning, clearly articulated objectives, marketing, end-user acceptance, and post-implementation plan revision.

  5. Artificial Intelligence Mechanisms on Interactive Modified Simplex Method with Desirability Function for Optimising Surface Lapping Process

    Directory of Open Access Journals (Sweden)

    Pongchanun Luangpaiboon

    2014-01-01

    Full Text Available A study has been made to optimise the influential parameters of surface lapping process. Lapping time, lapping speed, downward pressure, and charging pressure were chosen from the preliminary studies as parameters to determine process performances in terms of material removal, lap width, and clamp force. The desirability functions of the-nominal-the-best were used to compromise multiple responses into the overall desirability function level or D response. The conventional modified simplex or Nelder-Mead simplex method and the interactive desirability function are performed to optimise online the parameter levels in order to maximise the D response. In order to determine the lapping process parameters effectively, this research then applies two powerful artificial intelligence optimisation mechanisms from harmony search and firefly algorithms. The recommended condition of (lapping time, lapping speed, downward pressure, and charging pressure at (33, 35, 6.0, and 5.0 has been verified by performing confirmation experiments. It showed that the D response level increased to 0.96. When compared with the current operating condition, there is a decrease of the material removal and lap width with the improved process performance indices of 2.01 and 1.14, respectively. Similarly, there is an increase of the clamp force with the improved process performance index of 1.58.

  6. A Research Program on Artificial Intelligence in Process Engineering.

    Science.gov (United States)

    Stephanopoulos, George

    1986-01-01

    Discusses the use of artificial intelligence systems in process engineering. Describes a new program at the Massachusetts Institute of Technology which attempts to advance process engineering through technological advances in the areas of artificial intelligence and computers. Identifies the program's hardware facilities, software support,…

  7. Importance of a stable topoisomerase IB clamping for an efficient DNA processing: Effect of the Lys(369)Glu mutation.

    Science.gov (United States)

    Vieira, Sara; Castelli, Silvia; Desideri, Alessandro

    2015-11-01

    The role of lysine 369 of human topoisomerase IB in recognizing, clamping and processing its DNA substrate was experimentally investigated. Lys(369) is located in one of the two lips that interact to each other allowing the protein to embrace and firmly bind the DNA substrate. The lysine was mutated to a glutamate residue and the catalytic activity of the mutant enzyme was assayed. The mutant shows a distributive behavior, has a reduced binding to the substrate and a lower cleavage extent when compared to the wild type enzyme. The mutant displays reduced sensitivity to CPT both "in vitro" and in an "in vivo" yeast model, likely because of the low amount of cleaved DNA, however it displays cleavage and religation rates comparable to the wild type. These results demonstrate that the mutation causes a destabilization of the lips clamping around the DNA, impairing the protein-DNA interaction, emphasizing the importance of the ionic pair in tuning the stability of the protein-DNA complex. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. The UmuC subunit of the E. coli DNA polymerase V shows a unique interaction with the β-clamp processivity factor

    Science.gov (United States)

    2013-01-01

    Background Strict regulation of replisome components is essential to ensure the accurate transmission of the genome to the next generation. The sliding clamp processivity factors play a central role in this regulation, interacting with both DNA polymerases and multiple DNA processing and repair proteins. Clamp binding partners share a common peptide binding motif, the nature of which is essentially conserved from phage through to humans. Given the degree of conservation of these motifs, much research effort has focussed on understanding how the temporal and spatial regulation of multiple clamp binding partners is managed. The bacterial sliding clamps have come under scrutiny as potential targets for rational drug design and comprehensive understanding of the structural basis of their interactions is crucial for success. Results In this study we describe the crystal structure of a complex of the E. coli β-clamp with a 12-mer peptide from the UmuC protein. UmuC is the catalytic subunit of the translesion DNA polymerase, Pol V (UmuD’2C). Due to its potentially mutagenic action, Pol V is tightly regulated in the cell to limit access to the replication fork. Atypically for the translesion polymerases, both bacterial and eukaryotic, Pol V is heterotrimeric and its β-clamp binding motif (357 QLNLF 361) is internal to the protein, rather than at the more usual C-terminal position. Our structure shows that the UmuC peptide follows the overall disposition of previously characterised structures with respect to the highly conserved glutamine residue. Despite good agreement with the consensus β-clamp binding motif, distinct variation is shown within the hydrophobic binding pocket. While UmuC Leu-360 interacts as noted in other structures, Phe-361 does not penetrate the pocket at all, sitting above the surface. Conclusion Although the β-clamp binding motif of UmuC conforms to the consensus sequence, variation in its mode of clamp binding is observed compared to related

  9. Solution structure of an "open" E. coli Pol III clamp loader sliding clamp complex.

    Science.gov (United States)

    Tondnevis, Farzaneh; Weiss, Thomas M; Matsui, Tsutomu; Bloom, Linda B; McKenna, Robert

    2016-06-01

    Sliding clamps are opened and loaded onto primer template junctions by clamp loaders, and once loaded on DNA, confer processivity to replicative polymerases. Previously determined crystal structures of eukaryotic and T4 clamp loader-clamp complexes have captured the sliding clamps in either closed or only partially open interface conformations. In these solution structure studies, we have captured for the first time the clamp loader-sliding clamp complex from Escherichia coli using size exclusion chromatography coupled to small angle X-ray scattering (SEC-SAXS). The data suggests the sliding clamp is in an open conformation which is wide enough to permit duplex DNA binding. The data also provides information about spatial arrangement of the sliding clamp with respect to the clamp loader subunits and is compared to complex crystal structures determined from other organisms. Published by Elsevier Inc.

  10. Clamp usable as jig and lifting clamp

    Science.gov (United States)

    Tsuyama, Yoshizo

    1976-01-01

    There is provided a clamp which is well suited for use as a lifting clamp for lifting and moving materials of assembly in a shipyard, etc. and as a pulling jig in welding and other operations. The clamp comprises a clamp body including a shackle for engagement with a pulling device and a slot for receiving an article, and a pair of jaws provided on the leg portions of the clamp body on the opposite sides of the slot to grip the article in the slot, one of said jaws consisting of a screw rod and the other jaw consisting of a swivel jaw with a spherical surface, whereby when the article clamped in the slot by the pair of jaws tends to slide in any direction with respect to the clamp body, the article is more positively gripped by the pair of jaws.

  11. Analysis of Mental Processes Represented in Models of Artificial Consciousness

    Directory of Open Access Journals (Sweden)

    Luana Folchini da Costa

    2013-12-01

    Full Text Available The Artificial Consciousness concept has been used in the engineering area as being an evolution of the Artificial Intelligence. However, consciousness is a complex subject and often used without formalism. As a main contribution, in this work one proposes an analysis of four recent models of artificial consciousness published in the engineering area. The mental processes represented by these models are highlighted and correlations with the theoretical perspective of cognitive psychology are made. Finally, considerations about consciousness in such models are discussed.

  12. Artificial intelligence in process design and operation

    International Nuclear Information System (INIS)

    Sudduth, A.L.

    1988-01-01

    Artificial Intelligence (AI) has recently become prominent in the discussion of computer applications in the utility business. In order to assess this technology, a research project was performed to determine whether software development techniques based on AI could be used to facilitate management of information associated with the design of a generating station. The approach taken was the development of an expert system, using a relatively simple set of rules acting on a more complex knowledge base. A successful prototype for the application was developed and its potential extension to a production environment demonstrated. During the course of prototype development, other possible applications of AI in design engineering were discovered, and areas of particular interest selected for further investigation. A plan for AI R and D was formulated. That plan and other possible future work in AI are discussed

  13. Optimization of Drinking Water Treatment Processes Using Artificial ...

    African Journals Online (AJOL)

    Drinking water treatment is the process of removing microorganisms and solid from water through different methods such as coagulation and filtration. Artificial neural network (ANN) was developed for process and cost optimization of drinking water treatment processes. Results obtained from ANN model showed that ANN ...

  14. Design and analysis of different trigger techniques for ESD clamp circuit in 0.5-µm 5 V/18 V CDMOS process

    Science.gov (United States)

    Zhang, Wenjie; Yang, Liu; Wang, Yang; Jin, Xiangliang

    2017-09-01

    In this work, gate-driven, substrate-triggered and gate-substrate-triggered techniques for both 5 V NMOS-based and 18 V NLDMOS-based power clamps under electrostatic discharge (ESD) stress were investigated in details. Schematics of the three trigger designs were depicted and their physical mechanisms were studied at first. To verify and make comparisons of their performance, they were fabricated in a standard 0.5-μm 5 V/18 V CDMOS process and characterized by transmission line pulse (TLP) test system, respectively. Experimental results show that 5 V NMOS-based power clamp with substrate-triggered technique has the lowest trigger voltage (∼8.37 V) and the highest failure current (∼3.58 A), and 18 V gate-substrate-triggered design based on NLDMOS has low trigger voltage (∼34.02 V) and greatest robustness (It2 = 3.32 A). Therefore, as for low-voltage NMOS-based ESD power clamps, substrate-triggered design obtains the most superior ESD protection performance; but for high-voltage power clamps, gate-substrate-triggered technique can make NLDMOS actualize uniform current conduction and better ESD robustness.

  15. Artificial intelligence implementation in the APS process diagnostic

    International Nuclear Information System (INIS)

    Guessasma, Sofiane; Salhi, Zahir; Montavon, Ghislain; Gougeon, Patrick; Coddet, Christian

    2004-01-01

    Thermal spray process is a technique of coating manufacturing implementing a wide variety of materials and processes. This technique is characterized by up to 150 processing parameters influencing the coating properties. The control of the coating quality is needed through the consideration of a robust methodology that takes into account the parameter interdependencies, the process variability and offers the ability to quantify the processing parameter-process response relationships. The aim of this work is to introduce a new approach based on artificial intelligence responding to these requirements. A detailed procedure is presented considering an artificial neural network (ANN) structure which encodes implicitly the physical phenomena governing the process. The implementation of such a structure was coupled to experimental results of an optic sensor controlling the powder particle fusion state before the coating formation. The optimization steps were discussed and the predicted results were compared to the experimental ones allowing the identification of the control factors

  16. Artificial intelligence implementation in the APS process diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Guessasma, Sofiane; Salhi, Zahir; Montavon, Ghislain; Gougeon, Patrick; Coddet, Christian

    2004-07-25

    Thermal spray process is a technique of coating manufacturing implementing a wide variety of materials and processes. This technique is characterized by up to 150 processing parameters influencing the coating properties. The control of the coating quality is needed through the consideration of a robust methodology that takes into account the parameter interdependencies, the process variability and offers the ability to quantify the processing parameter-process response relationships. The aim of this work is to introduce a new approach based on artificial intelligence responding to these requirements. A detailed procedure is presented considering an artificial neural network (ANN) structure which encodes implicitly the physical phenomena governing the process. The implementation of such a structure was coupled to experimental results of an optic sensor controlling the powder particle fusion state before the coating formation. The optimization steps were discussed and the predicted results were compared to the experimental ones allowing the identification of the control factors.

  17. Generating Artificial Event Logs with Sufficient Discriminatory Power to Compare Process Discovery Techniques

    OpenAIRE

    JOUCK, Toon; Depaire, Benoit

    2014-01-01

    Past research revealed issues with artificial event data used for comparative analysis of process mining algorithms. The aim of this research is to design, implement and validate a framework for producing artificial event logs which should increase discriminatory power of artificial event logs when evaluating process discovery techniques. artificial event logs; event log simulation; performance measurement of business processes

  18. A Course in Artificial Intelligence in Process Engineering.

    Science.gov (United States)

    Venkatasubramanian, V.

    1986-01-01

    Describes a course on artificial intelligence (AI) in process engineering taught at Columbia University to chemical engineering students, using an AI methodology known as Knowledge-Based Expert Systems (KBES). Provides a description of the course, the lecture topics, and a synopsis of some of the student projects. (TW)

  19. Recurrent Artificial Neural Networks and Finite State Natural Language Processing.

    Science.gov (United States)

    Moisl, Hermann

    It is argued that pessimistic assessments of the adequacy of artificial neural networks (ANNs) for natural language processing (NLP) on the grounds that they have a finite state architecture are unjustified, and that their adequacy in this regard is an empirical issue. First, arguments that counter standard objections to finite state NLP on the…

  20. Quick-attach clamp

    Science.gov (United States)

    Vano, A. E.

    1968-01-01

    Clamp of the slideable jaw type can be applied to moving lines such as cables or ropes. The clamp has a trigger-operated jaw that can be attached to a redrop parachute on a moving tow cable. The trigger mechanism maintains the jaws retracted in the housing until they are released for clamping.

  1. Photovoltaic panel clamp

    Science.gov (United States)

    Mittan, Margaret Birmingham [Oakland, CA; Miros, Robert H. J. [Fairfax, CA; Brown, Malcolm P [San Francisco, CA; Stancel, Robert [Loss Altos Hills, CA

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  2. Kinetic analysis of PCNA clamp binding and release in the clamp loading reaction catalyzed by Saccharomyces cerevisiae replication factor C.

    Science.gov (United States)

    Marzahn, Melissa R; Hayner, Jaclyn N; Meyer, Jennifer A; Bloom, Linda B

    2015-01-01

    DNA polymerases require a sliding clamp to achieve processive DNA synthesis. The toroidal clamps are loaded onto DNA by clamp loaders, members of the AAA+family of ATPases. These enzymes utilize the energy of ATP binding and hydrolysis to perform a variety of cellular functions. In this study, a clamp loader-clamp binding assay was developed to measure the rates of ATP-dependent clamp binding and ATP-hydrolysis-dependent clamp release for the Saccharomyces cerevisiae clamp loader (RFC) and clamp (PCNA). Pre-steady-state kinetics of PCNA binding showed that although ATP binding to RFC increases affinity for PCNA, ATP binding rates and ATP-dependent conformational changes in RFC are fast relative to PCNA binding rates. Interestingly, RFC binds PCNA faster than the Escherichia coli γ complex clamp loader binds the β-clamp. In the process of loading clamps on DNA, RFC maintains contact with PCNA while PCNA closes, as the observed rate of PCNA closing is faster than the rate of PCNA release, precluding the possibility of an open clamp dissociating from DNA. Rates of clamp closing and release are not dependent on the rate of the DNA binding step and are also slower than reported rates of ATP hydrolysis, showing that these rates reflect unique intramolecular reaction steps in the clamp loading pathway. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Artificial intelligence, expert systems, computer vision, and natural language processing

    Science.gov (United States)

    Gevarter, W. B.

    1984-01-01

    An overview of artificial intelligence (AI), its core ingredients, and its applications is presented. The knowledge representation, logic, problem solving approaches, languages, and computers pertaining to AI are examined, and the state of the art in AI is reviewed. The use of AI in expert systems, computer vision, natural language processing, speech recognition and understanding, speech synthesis, problem solving, and planning is examined. Basic AI topics, including automation, search-oriented problem solving, knowledge representation, and computational logic, are discussed.

  4. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. The design considerations and methods along with the development tests are presented. Special considerations to guard against adverse cracking of the insulation material, to maintain the clamp-pipe stiffness desired during a seismic event, to minimize clamp restraint on the pipe during normal pipe heatup, and to resist clamp rotation or spinning on the pipe are emphasized

  5. Insulated pipe clamp design

    International Nuclear Information System (INIS)

    Anderson, M.J.; Hyde, L.L.; Wagner, S.E.; Severud, L.K.

    1980-01-01

    Thin wall large diameter piping for breeder reactor plants can be subjected to significant thermal shocks during reactor scrams and other upset events. On the Fast Flux Test Facility, the addition of thick clamps directly on the piping was undesired because the differential metal temperatures between the pipe wall and the clamp could have significantly reduced the pipe thermal fatigue life cycle capabilities. Accordingly, an insulated pipe clamp design concept was developed. 5 refs

  6. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  7. Natural language processing in psychiatry. Artificial intelligence technology and psychopathology.

    Science.gov (United States)

    Garfield, D A; Rapp, C; Evens, M

    1992-04-01

    The potential benefit of artificial intelligence (AI) technology as a tool of psychiatry has not been well defined. In this essay, the technology of natural language processing and its position with regard to the two main schools of AI is clearly outlined. Past experiments utilizing AI techniques in understanding psychopathology are reviewed. Natural language processing can automate the analysis of transcripts and can be used in modeling theories of language comprehension. In these ways, it can serve as a tool in testing psychological theories of psychopathology and can be used as an effective tool in empirical research on verbal behavior in psychopathology.

  8. Clamp loader ATPases and the evolution of DNA replication machinery

    Science.gov (United States)

    2012-01-01

    Clamp loaders are pentameric ATPases of the AAA+ family that operate to ensure processive DNA replication. They do so by loading onto DNA the ring-shaped sliding clamps that tether the polymerase to the DNA. Structural and biochemical analysis of clamp loaders has shown how, despite differences in composition across different branches of life, all clamp loaders undergo the same concerted conformational transformations, which generate a binding surface for the open clamp and an internal spiral chamber into which the DNA at the replication fork can slide, triggering ATP hydrolysis, release of the clamp loader, and closure of the clamp round the DNA. We review here the current understanding of the clamp loader mechanism and discuss the implications of the differences between clamp loaders from the different branches of life. PMID:22520345

  9. Clamp Restrains Pressure Line

    Science.gov (United States)

    Aliberti, J. A.

    1982-01-01

    Safety restraint protects people and property if a high-pressure fitting fails. As long as pressure line remains attached at the fitting, clamp exerts essentially no force on hose. If fitting fails, force of fluid leaving free end of hose causes the cam on the clamp to compress hose with a positive locking action.

  10. Quick action clamp

    Science.gov (United States)

    Calco, Frank S. (Inventor)

    1991-01-01

    A quick release toggle clamp that utilizes a spring that requires a deliberate positive action for disengagement is presented. The clamp has a sliding bolt that provides a latching mechanism. The bolt is moved by a handle that tends to remain in an engaged position while under tension.

  11. Studies in artificial aphasia: experiments in processing change.

    Science.gov (United States)

    Gigley, H M

    1986-03-01

    Computational neurolinguistics, an integrated approach to cognitive modelling of neural processes which may subserve natural language performance, attempts to build computational models that model behavior on two levels: at the neural process level and at the human performance level in its normal state and under pathological conditions. HOPE is one example of such a model. It demonstrates how the design and implementation of such models can provide insights into how a brain-like architecture can produce a behavior as complex as natural language. This paper will briefly describe the neurally motivated or 'natural computation' processes which produce the model's observable and verifiable behavioral results. Experiments with artificially induced aphasia on HOPE will then be described, showing that the results of simulation produce hypothesized patient profiles that are unique. These profiles illustrate the suggested contribution of the computational neurolinguistics research approach as a tool for investigating the breakdown of language performance and its potential contribution to understanding brain function.

  12. APPLICATION OF ARTIFICIAL INTELLIGENCE TECHNIQUES IN PROCESS FAULT DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    M.A. HUSSAIN

    2007-12-01

    Full Text Available Chemical processes are systems that include complicated network of material, energy and process flow. As time passes, the performance of chemical process gradually degrades due to the deterioration of process equipments and components. The early detection and diagnosis of faults in chemical processes is very important both from the viewpoint of plant safety as well as reduced manufacturing costs. The conventional way used in fault detection and diagnosis is through the use of models of the process, which is not easy to be achieved in many cases. In recent years, an artificial intelligence technique such as neural network has been successfully used for pattern recognition and as such it can be suitable for use in fault diagnosis of processes [1]. The application of neural network methods in process fault detection and diagnosis is demonstrated in this work in two case studies using simulated chemical plant systems. Both systems were successfully diagnosed of the faults introduced in them. The neural networks were able to generalise to successfully diagnosed fault combinations it was not explicitly trained upon. Thus, neural network can be fully applied in industries as it has shown several advantages over the conventional way in fault diagnosis.

  13. Clamp-mount device

    Science.gov (United States)

    Clark, K. H. (Inventor)

    1983-01-01

    A clamp-mount device is disclosed for mounting equipment to an associated I-beam and the like structural member of the type having oppositely extending flanges wherein the device comprises a base and a pair of oppositely facing clamping members carried diagonally on the base clamping flanges therebetween and having flange receiving openings facing one another. Lock means are carried diagonally by the base opposite the clamping members locking the flanges in the clamping members. A resilient hub is carried centrally of the base engaging and biasing a back side of the flanges maintaining tightly clamped and facilitating use on vertical as well as horizontal members. The base turns about the hub to receive the flanges within the clamping members. Equipment may be secured to the base by any suitable means such as bolts in openings. Slidable gate latches secure the hinged locks in an upright locking position. The resilient hub includes a recess opening formed in the base and a rubber-like pad carried in this opening being depressably and rotatably carried therein.

  14. Integrating artificial and human intelligence into tablet production process.

    Science.gov (United States)

    Gams, Matjaž; Horvat, Matej; Ožek, Matej; Luštrek, Mitja; Gradišek, Anton

    2014-12-01

    We developed a new machine learning-based method in order to facilitate the manufacturing processes of pharmaceutical products, such as tablets, in accordance with the Process Analytical Technology (PAT) and Quality by Design (QbD) initiatives. Our approach combines the data, available from prior production runs, with machine learning algorithms that are assisted by a human operator with expert knowledge of the production process. The process parameters encompass those that relate to the attributes of the precursor raw materials and those that relate to the manufacturing process itself. During manufacturing, our method allows production operator to inspect the impacts of various settings of process parameters within their proven acceptable range with the purpose of choosing the most promising values in advance of the actual batch manufacture. The interaction between the human operator and the artificial intelligence system provides improved performance and quality. We successfully implemented the method on data provided by a pharmaceutical company for a particular product, a tablet, under development. We tested the accuracy of the method in comparison with some other machine learning approaches. The method is especially suitable for analyzing manufacturing processes characterized by a limited amount of data.

  15. Bend-absorbing clamp

    Science.gov (United States)

    Abbott, J. R.; Valencia, B., Jr.

    1979-01-01

    Compact, inexpensive clamp for flexible cables or rigid tubes absorbs vibrations and other motion. It accomodates wide range of dimensions, and saves space by eliminating pigtails or bellows commonly used to absorb linear movement or vibrations

  16. Analysis of the Pallet Clamping Conditions in Work Positioning

    Directory of Open Access Journals (Sweden)

    L. A. Kolesnikov

    2016-01-01

    Full Text Available Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and defines the conditions to ensure the trouble-free clamping lock. The circular and rhombic clamping of pallet is simultaneous. Further, a clamping load is calculated from the pallet mass (together with the work-piece and the geometric parameters of the pallet clamping.The paper reveals three movement stages of the clamping lock in a vertical plane when setting the pallet in work positioning:- a clamping lock free play till it encounters with the location bushing;- a clamping lock play length when the lead-in chamfer contacts the bushing chamfer;- a clamping lock play length over the circular surface of bushing.The study of this process has allowed us to calculate the time of pallet clamping and dynamic loads acting on the clamping lock. These calculations made it possible to calculate the required diameter of the clamping lock. The presented calculations allow a reasonable assigning the main design parameters of work positioning for the pallet automatic lines.

  17. Artificial intelligence in NMR imaging and image processing

    International Nuclear Information System (INIS)

    Kuhn, M.H.

    1988-01-01

    NMR tomography offers a wealth of information and data acquisition variants. Artificial intelligence is able to efficiently support the selection of measuring parameters and the evaluation of results. (orig.) [de

  18. Clamp for detonating fuze

    Science.gov (United States)

    Holderman, E. J.

    1968-01-01

    Quick acting clamp provides physical support for a closely confined detonating fuse in an application requiring removal and replacement at frequent intervals during test. It can be designed with a base of any required strength and configuration to permit the insertion of an object.

  19. Design and fabrication process for artificial lateral line sensors

    NARCIS (Netherlands)

    Izadi, N.; Krijnen, Gijsbertus J.M.; Barth, Friedrich G.; Humphrey, Joseph A.C.; Srinivasan, Mandyam V.

    2011-01-01

    Biological sensory systems often display great performance, inspiring engineers to develop artificial counterparts. The lateral line system of fish has been widely studied by biologists for its crucial role in fish behaviour. Moreover, recently the robustness, sensitivity and consequently wide range

  20. Artificial Intelligence in ADA: Pattern-Directed Processing. Final Report.

    Science.gov (United States)

    Reeker, Larry H.; And Others

    To demonstrate to computer programmers that the programming language Ada provides superior facilities for use in artificial intelligence applications, the three papers included in this report investigate the capabilities that exist within Ada for "pattern-directed" programming. The first paper (Larry H. Reeker, Tulane University) is…

  1. Detection of hybridization of single-strand DNA PCR products in temperature change process by a novel metal-clamping piezoelectric sensor.

    Science.gov (United States)

    Chen, Qinghai; Bian, Zhiheng; Hua, Xing; Yao, Chunyan; Wu, Wei; Zhang, Xue; Zhang, Bo; Huang, Junfu; Tang, Wanli; Fu, Weiling

    2010-05-15

    Oligonucleotide probes on the sensor surface can be hybridized with single-strand DNA (ssDNA) that is formed from PCR products in ice bath after degeneration. Thus, detection of PCR products by piezoelectric sensors requires the participation of ssDNA PCR products in ice bath. When PCR products in ice bath are added into the buffer of the sensor well at room temperature, there will be a temperature change process during mixing. However, it still remains unclear whether the temperature change affects the frequency baseline stability of the sensor and the result judgment, which is the basic condition for detecting hybridization of nucleic acid. In this study, we detected the hybridization of HPV PCR products during temperature change process by a self-designed adjustable metal-clamping piezoelectric sensor. The study mainly involves sensor adjustment, probe immobilization and ice bath sample addition (at different concentrations and different volumes). The response curve of basic frequency in temperature change process showed three stages, i.e., increase, decrease to baseline, and continuous decrease to stability. The early increase of frequency and duration of the time can reach 55+/-7.4 Hz and 39 min when 40 microL sample (0-1 degrees C) was added into 110 microL buffer (25 degrees C). The frequency increase effect caused by temperature difference at early stage depends on the volume ratio of two liquids and on the temperature difference. The results indicate that we should pay more attention to possibly small volume of PCR products in ice bath and minor temperature difference of two liquids in operation. 2010 Elsevier B.V. All rights reserved.

  2. The ATP Sites of AAA+ Clamp Loaders Work Together as a Switch to Assemble Clamps on DNA*

    Science.gov (United States)

    Marzahn, Melissa R.; Hayner, Jaclyn N.; Finkelstein, Jeff; O'Donnell, Mike; Bloom, Linda B.

    2014-01-01

    Clamp loaders belong to a family of proteins known as ATPases associated with various cellular activities (AAA+). These proteins utilize the energy from ATP binding and hydrolysis to perform cellular functions. The clamp loader is required to load the clamp onto DNA for use by DNA polymerases to increase processivity. ATP binding and hydrolysis are coordinated by several key residues, including a conserved Lys located within the Walker A motif (or P-loop). This residue is required for each subunit to bind ATP. The specific function of each ATP molecule bound to the Saccharomyces cerevisiae clamp loader is unknown. A series of point mutants, each lacking a single Walker A Lys residue, was generated to study the effects of abolishing ATP binding in individual clamp loader subunits. A variety of biochemical assays were used to analyze the function of ATP binding during discrete steps of the clamp loading reaction. All mutants reduced clamp binding/opening to different degrees. Decreased clamp binding activity was generally correlated with decreases in the population of open clamps, suggesting that differences in the binding affinities of Walker A mutants stem from differences in stabilization of proliferating cell nuclear antigen in an open conformation. Walker A mutations had a smaller effect on DNA binding than clamp binding/opening. Our data do not support a model in which each ATP site functions independently to regulate a different step in the clamp loading cycle to coordinate these steps. Instead, the ATP sites work in unison to promote conformational changes in the clamp loader that drive clamp loading. PMID:24436332

  3. The ATP sites of AAA+ clamp loaders work together as a switch to assemble clamps on DNA.

    Science.gov (United States)

    Marzahn, Melissa R; Hayner, Jaclyn N; Finkelstein, Jeff; O'Donnell, Mike; Bloom, Linda B

    2014-02-28

    Clamp loaders belong to a family of proteins known as ATPases associated with various cellular activities (AAA+). These proteins utilize the energy from ATP binding and hydrolysis to perform cellular functions. The clamp loader is required to load the clamp onto DNA for use by DNA polymerases to increase processivity. ATP binding and hydrolysis are coordinated by several key residues, including a conserved Lys located within the Walker A motif (or P-loop). This residue is required for each subunit to bind ATP. The specific function of each ATP molecule bound to the Saccharomyces cerevisiae clamp loader is unknown. A series of point mutants, each lacking a single Walker A Lys residue, was generated to study the effects of abolishing ATP binding in individual clamp loader subunits. A variety of biochemical assays were used to analyze the function of ATP binding during discrete steps of the clamp loading reaction. All mutants reduced clamp binding/opening to different degrees. Decreased clamp binding activity was generally correlated with decreases in the population of open clamps, suggesting that differences in the binding affinities of Walker A mutants stem from differences in stabilization of proliferating cell nuclear antigen in an open conformation. Walker A mutations had a smaller effect on DNA binding than clamp binding/opening. Our data do not support a model in which each ATP site functions independently to regulate a different step in the clamp loading cycle to coordinate these steps. Instead, the ATP sites work in unison to promote conformational changes in the clamp loader that drive clamp loading.

  4. Brain signatures of artificial language processing: Evidence challenging the critical period hypothesis

    OpenAIRE

    Friederici, Angela D.; Steinhauer, Karsten; Pfeifer, Erdmut

    2002-01-01

    Adult second language learning seems to be more difficult and less efficient than first language acquisition during childhood. By using event-related brain potentials, we show that adults who learned a miniature artificial language display a similar real-time pattern of brain activation when processing this language as native speakers do when processing natural languages. Participants trained in the artificial language showed two event-related brain potential compo...

  5. The application of neural networks with artificial intelligence technique in the modeling of industrial processes

    International Nuclear Information System (INIS)

    Saini, K. K.; Saini, Sanju

    2008-01-01

    Neural networks are a relatively new artificial intelligence technique that emulates the behavior of biological neural systems in digital software or hardware. These networks can 'learn', automatically, complex relationships among data. This feature makes the technique very useful in modeling processes for which mathematical modeling is difficult or impossible. The work described here outlines some examples of the application of neural networks with artificial intelligence technique in the modeling of industrial processes.

  6. Hand-Held Power Clamp

    Science.gov (United States)

    Clancy, J. P.

    1985-01-01

    Tool furnishes large pushing or pulling forces. Device includes two clamping blocks, two clamping plates, and a motor-driven linear actuator with selflocking screw shaft. Power clamp exerts opening or closing force at push of switch. Tool approximately 1 m long. Originally designed to secure payload aboard Space Shuttle, operated with one hand to apply opening or closing force of up to 1,000 lb (4,400 N). Clamp has potential applications as end effector for industrial robots and in rescue work to push or pull wreckage with great force.

  7. Sentence processing in an artificial language: Learning and using combinatorial constraints.

    Science.gov (United States)

    Amato, Michael S; MacDonald, Maryellen C

    2010-07-01

    A study combining artificial grammar and sentence comprehension methods investigated the learning and online use of probabilistic, nonadjacent combinatorial constraints. Participants learned a small artificial language describing cartoon monsters acting on objects. Self-paced reading of sentences in the artificial language revealed comprehenders' sensitivity to nonadjacent combinatorial constraints, without explicit awareness of the probabilities embedded in the language. These results show that even newly-learned constraints have an identifiable effect on online sentence processing. The rapidity of learning in this paradigm relative to others has implications for theories of implicit learning and its role in language acquisition. 2010 Elsevier B.V. All rights reserved.

  8. Modeling of Steam Distillation Mechanism during Steam Injection Process Using Artificial Intelligence

    OpenAIRE

    Daryasafar, Amin; Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulat...

  9. Sorption and biodegradation of artificial sweeteners in activated sludge processes.

    Science.gov (United States)

    Tran, Ngoc Han; Gan, Jie; Nguyen, Viet Tung; Chen, Huiting; You, Luhua; Duarah, Ankur; Zhang, Lifeng; Gin, Karina Yew-Hoong

    2015-12-01

    There is limited information on the occurrence and removal of artificial sweeteners (ASs) in biological wastewater treatment plants, and in particular, the contribution of sorption and biodegradation to their removal. This study investigated the fate of ASs in both the aqueous and solid phases in a water reclamation plant (WRP). All the four targeted ASs, i.e. acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharine (SAC), were detected in both the aqueous and solid phases of raw influent and primary effluent samples. The concentrations of CYC and SAC in secondary effluent or MBR permeate were below their method detection limits. ACE and SUC were persistent throughout the WRP, whereas CYC and SAC were completely removed in biological treatment (>99%). Experimental results showed that sorption played a minor role in the elimination of the ASs due to the relatively low sorption coefficients (Kd), where Kd<500L/kg. In particular, the poor removal of ACE and SUC in the WRP may be attributed to their physiochemical properties (i.e. logKow<0 or logD<3.2) and chemical structures containing strong withdrawing electron functional groups in heterocyclic rings (i.e. chloride and sulfonate). Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Study on Electro-Polishing Process by Niobium-Plate Sample With Artificial Pits

    Energy Technology Data Exchange (ETDEWEB)

    T. Saeki, H. Hayano, S. Kato, M. Nishiwaki, M. Sawabe, W.A. Clemens, R.L. Geng, R. Manus, P.V. Tyagi

    2011-07-01

    The Electro-polishing (EP) process is the best candidate of final surface-treatment for the production of ILC cavities. Nevertheless, the development of defects on the inner-surface of the Superconducting RF cavity during EP process has not been studied by experimental method. We made artificial pits on the surface of a Nb-plate sample and observed the development of the pit-shapes after each step of 30um-EP process where 120um was removed by EP in total. This article describes the results of this EP-test of Nb-sample with artificial pits.

  11. Review: The lord of the rings: Structure and mechanism of the sliding clamp loader.

    Science.gov (United States)

    Kelch, Brian A

    2016-08-01

    Sliding clamps are ring-shaped polymerase processivity factors that act as master regulators of cellular replication by coordinating multiple functions on DNA to ensure faithful transmission of genetic and epigenetic information. Dedicated AAA+ ATPase machines called clamp loaders actively place clamps on DNA, thereby governing clamp function by controlling when and where clamps are used. Clamp loaders are also important model systems for understanding the basic principles of AAA+ mechanism and function. After nearly 30 years of study, the ATP-dependent mechanism of opening and loading of clamps is now becoming clear. Here I review the structural and mechanistic aspects of the clamp loading process, as well as comment on questions that will be addressed by future studies. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 532-546, 2016. © 2016 Wiley Periodicals, Inc.

  12. Using Dual-Task Methodology to Dissociate Automatic from Nonautomatic Processes Involved in Artificial Grammar Learning

    Science.gov (United States)

    Hendricks, Michelle A.; Conway, Christopher M.; Kellogg, Ronald T.

    2013-01-01

    Previous studies have suggested that both automatic and intentional processes contribute to the learning of grammar and fragment knowledge in artificial grammar learning (AGL) tasks. To explore the relative contribution of automatic and intentional processes to knowledge gained in AGL, we utilized dual-task methodology to dissociate automatic and…

  13. Application of Artificial Neural Networks and Chaos in Chemical Processes

    Science.gov (United States)

    Otawara, Kentaro

    1995-01-01

    An artificial neural network (ANN) and chaos, conceived and developed independently, are beginning to play essential roles in chemical engineering. Nonetheless, the ANN possesses an appreciable number of deficiencies that need be remedied, and the capability of the ANN to explore and tame chaos or an irregularly behaving system is yet to be fully realized. The present dissertation attempts to make substantial progress toward such ends. The problem of controlling the temperature of an industrial reactor carrying out semibatch polymerization has been solved by an innovative adaptive hybrid control system comprising an ANN and fuzzy expert system (FES) complemented by two supervisory ANN's. The system enhances the strength and compensates for the weaknesses of both the ANN and FES. The system, named dual ANN (DANN), has been proposed for characterizing the nonlinear nature of chaotic time -series data. Its capability to approximate the behavior of a chaotic system has been found to far exceed that of a conventional ANN. A novel approach has been devised for training an ANN through the modified interactive training (MIT) mode. This mode of training has been demonstrated to substantially outperform a conventional interactive training (CIT) mode. A method has been established for synchronizing chaos by resorting to an ANN. This method is capable of causing to be coherent the trajectories of systems whose deterministic governing equations are insufficiently known. This requires training the ANN with a time series and a common driving signal or signals. Examples are given for chaos generated by difference as well as differential equations. An alternative to the OGY method has been proposed for controlling chaos; it meticulously perturbs an accessible parameter of the chaotic system. A single, highly precise ANN suffices to render stable any of an infinite number of unstable periodic orbits embedded in a chaotic or strange attractor. A method for estimating sub

  14. A Fast-Processing Modulation Strategy for Three-Phase Four-Leg Neutral-Point-Clamped Inverter Based on the Circuit-Level Decoupling Concept

    DEFF Research Database (Denmark)

    Ghoreishy, Hoda; Zhang, Zhe; Thomsen, Ole Cornelius

    2012-01-01

    In this paper, a modulation strategy based on the circuit-level decoupling concept is proposed and investigated for the three-level four-leg neutral-point-clamped (NPC) inverter,with the aim of delivering power to all sorts of loads, linear/nonlinear and balanced/unbalanced. By applying...... the proposed modulation strategy, the four-leg NPC inverter can be decoupled into three three-level Buck converters in each defined operating section. This makes the controller design much simpler compared to the conventional four-leg NPC inverter controllers. Also, this technique can be implemented...

  15. Enhancing the Scientific Process with Artificial Intelligence: Forest Science Applications

    Science.gov (United States)

    Ronald E. McRoberts; Daniel L. Schmoldt; H. Michael Rauscher

    1991-01-01

    Forestry, as a science, is a process for investigating nature. It consists of repeatedly cycling through a number of steps, including identifying knowledge gaps, creating knowledge to fill them, and organizing, evaluating, and delivering this knowledge. Much of this effort is directed toward creating abstract models of natural phenomena. The cognitive techniques of AI...

  16. Genetic Algorithms vs. Artificial Neural Networks in Economic Forecasting Process

    Directory of Open Access Journals (Sweden)

    Nicolae Morariu

    2008-01-01

    Full Text Available This paper aims to describe the implementa-tion of a neural network and a genetic algorithm system in order to forecast certain economic indicators of a free market economy. In a free market economy forecasting process precedes the economic planning (a management function, providing important information for the result of the last process. Forecasting represents a starting point in setting of target for a firm, an organization or even a branch of the economy. Thus, the forecasting method used can influence in a significant mode the evolution of an entity. In the following we will describe the forecasting of an economic indicator using two intelligent systems. The difference between the results obtained by this two systems are described in chapter IV.

  17. Application of Artificial Neural Networks for Process Identification and Control

    OpenAIRE

    Bolf, N.; Jerbić, I.

    2006-01-01

    During the development of intelligent systems inspired by biological neural system, in the last two decades the researchers from various scientific fields have created neural networks for solving a series of problems from pattern recognition, prediction, diagnostic, software sensor, modelling and identification, control and optimization. In this paper a review of neural network application in the field of chemical engineering with emphasis on identification and process control is given. T...

  18. Internal V-Band Clamp

    Science.gov (United States)

    Vaughn, Mark R.; Hafenrichter, Everett S.; Chapa, Agapito C.; Harris, Steven M.; Martinez, Marcus J.; Baty, Roy S.

    2006-02-28

    A system for clamping two tubular members together in an end-to-end relationship uses a split ring with a V-shaped outer rim that can engage a clamping surface on each member. The split ring has a relaxed closed state where the ends of the ring are adjacent and the outside diameter of the split ring is less than the minimum inside diameter of the members at their ends. The members are clamped when the split ring is spread into an elastically stretched position where the ring rim is pressed tightly against the interior surfaces of the members. Mechanisms are provided for removing the spreader so the split ring will return to the relaxed state, releasing the clamped members.

  19. Intelligent process control operator aid -- An artificial intelligence approach

    International Nuclear Information System (INIS)

    Sharma, D.D.; Miller, D.D.; Hajek, B.; Chandrasekaran, B.

    1986-01-01

    This paper describes an approach for designing intelligent process and power plant control operator aids. It is argued that one of the key aspects of an intelligent operator aid is the capability for dynamic procedure synthesis with incomplete definition of initial state, unknown goal states, and the dynamic world situation. The dynamic world state is used to determine the goal, select appropriate plan steps from prespecified procedures to achieve the goal, control the execution of the synthesized plan, and provide for dynamic recovery from failure often using a goal hierarchy. The dynamic synthesis of a plan requires integration of various problems solving capabilities such as plan generation, plan synthesis, plan modification, and failure recovery from a plan. The programming language for implementing the DPS framework provides a convenient tool for developing applications. An application of the DPS approach to a Nuclear Power Plant emergency procedure synthesis is also described. Initial test results indicate that the approach is successful in dynamically synthesizing the procedures. The authors realize that the DPS framework is not a solution for all control tasks. However, many existing process and plant control problems satisfy the requirements discussed in the paper and should be able to benefit from the framework described

  20. PCR assessment of Chlamydia trachomatis infection of semen specimens processed for artificial insemination

    NARCIS (Netherlands)

    Pannekoek, Y.; Westenberg, S. M.; de Vries, J.; Repping, S.; Spanjaard, L.; Eijk, P. P.; van der Ende, A.; Dankert, J.

    2000-01-01

    In order to ascertain the microbiological quality of stored semen specimens processed for artificial insemination by a donor (AID), we developed a PCR assay targeting the chlamydial plasmid to detect Chlamydia trachomatis in semen. The lower limit of detection of this assay corresponded to 2.5 to 5

  1. Brain signatures of artificial language processing: evidence challenging the critical period hypothesis.

    Science.gov (United States)

    Friederici, Angela D; Steinhauer, Karsten; Pfeifer, Erdmut

    2002-01-08

    Adult second language learning seems to be more difficult and less efficient than first language acquisition during childhood. By using event-related brain potentials, we show that adults who learned a miniature artificial language display a similar real-time pattern of brain activation when processing this language as native speakers do when processing natural languages. Participants trained in the artificial language showed two event-related brain potential components taken to reflect early automatic and late controlled syntactic processes, whereas untrained participants did not. This result challenges the common view that late second language learners process language in a principally different way from native speakers. Our findings demonstrate that a small system of grammatical rules can be syntactically instantiated by the adult speaker in a way that strongly resembles native-speaker sentence processing.

  2. Artificial neural networks in variable process control: application in particleboard manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, L. G.; Garcia Fernandez, F.; Palacios, P. de; Conde, M.

    2009-07-01

    Artificial neural networks are an efficient tool for modelling production control processes using data from the actual production as well as simulated or design of experiments data. In this study two artificial neural networks were combined with the control process charts and it was checked whether the data obtained by the networks were valid for variable process control in particleboard manufacture. The networks made it possible to obtain the mean and standard deviation of the internal bond strength of the particleboard within acceptable margins using known data of thickness, density, moisture content, swelling and absorption. The networks obtained met the acceptance criteria for test values from non-standard test methods, as well as the criteria for using these values in statistical process control. (Author) 47 refs.

  3. Application of artificial neural networks and genetic algorithms for crude fractional distillation process modeling

    OpenAIRE

    Pater, Lukasz

    2016-01-01

    This work presents the application of the artificial neural networks, trained and structurally optimized by genetic algorithms, for modeling of crude distillation process at PKN ORLEN S.A. refinery. Models for the main fractionator distillation column products were developed using historical data. Quality of the fractions were predicted based on several chosen process variables. The performance of the model was validated using test data. Neural networks used in companion with genetic algorith...

  4. Automated business process management – in times of digital transformation using machine learning or artificial intelligence

    Directory of Open Access Journals (Sweden)

    Paschek Daniel

    2017-01-01

    Full Text Available The continuous optimization of business processes is still a challenge for companies. In times of digital transformation, faster changing internal and external framework conditions and new customer expectations for fastest delivery and best quality of goods and many more, companies should set up their internal process at the best way. But what to do if framework conditions changed unexpectedly? The purpose of the paper is to analyse how the digital transformation will impact the Business Process Management (BPM while using methods like machine learning or artificial intelligence. Therefore, the core components will be explained, compared and set up in relation. To identify application areas interviews and analysis will be held up with digital companies. The finding of the paper will be recommendation for action in the field of BPM and process optimization through machine learning and artificial intelligence. The Approach of optimizing and management processes via machine learning and artificial intelligence will support companies to decide which tool will be the best for automated BPM.

  5. How to Assess the Quality of Glucose Clamps? Evaluation of Clamps Performed With ClampArt, a Novel Automated Clamp Device.

    Science.gov (United States)

    Benesch, Carsten; Heise, Tim; Klein, Oliver; Heinemann, Lutz; Arnolds, Sabine

    2015-07-01

    There are no widely accepted parameters to assess the quality of glucose clamps. Thus, we selected different parameters describing clamp quality. These parameters were then evaluated in glucose clamps carried out with ClampArt, a novel CE-marked, state-of-the-art fully automated glucose clamp device employing continuous blood glucose (BG) measurements and minute-by-minute adaptations of glucose infusion rate (GIR). Thirty-nine glucose clamps were performed in 10 healthy and 29 subjects with type 1 diabetes (T1DM) (total duration 583 h). ClampArt-based BG measurements were compared with those obtained with a laboratory reference method. Clamp quality was assessed by 5 parameters: (1) difference (mg/dl) of all paired BG measurements of ClampArt versus reference method ("trueness"), (2) coefficient of variation (CV, %) of ClampArt's BG measurements at target clamp level ("precision"), (3) mean absolute relative difference (MARD, %) at target clamp level ("accuracy"), (4) difference (mg/dl) between ClampArt and target BG ("control deviation"), and (5) percentage operational time ("utility"). ClampArt-based BG measurements showed a trueness of 1.2 ± 2.5 mg/dl. CV and MARD at target BG were 5.5 ± 2.1% and 5.3 ± 2.3%, respectively. There were only small deviations from target level (1.2 ± 1.6 mg/dl). Operational time was as high as 95.4% ± 4.1% (means ± SD). The selected parameters seem to be adequate to characterize clamp quality. The novel, fully automated clamp device ClampArt achieves high clamp quality, which in future trials should be compared with other (automated and manual) clamp methods. © 2015 Diabetes Technology Society.

  6. Micromachined patch-clamp apparatus

    Science.gov (United States)

    Okandan, Murat

    2012-12-04

    A micromachined patch-clamp apparatus is disclosed for holding one or more cells and providing electrical, chemical, or mechanical stimulation to the cells during analysis with the patch-clamp technique for studying ion channels in cell membranes. The apparatus formed on a silicon substrate utilizes a lower chamber formed from silicon nitride using surface micromachining and an upper chamber formed from a molded polymer material. An opening in a common wall between the chambers is used to trap and hold a cell for analysis using the patch-clamp technique with sensing electrodes on each side of the cell. Some embodiments of the present invention utilize one or more electrostatic actuators formed on the substrate to provide mechanical stimulation to the cell being analyzed, or to provide information about mechanical movement of the cell in response to electrical or chemical stimulation.

  7. Quadratic sinusoidal analysis of voltage clamped neurons.

    Science.gov (United States)

    Magnani, Christophe; Moore, Lee E

    2011-11-01

    Nonlinear biophysical properties of individual neurons are known to play a major role in the nervous system, especially those active at subthreshold membrane potentials that integrate synaptic inputs during action potential initiation. Previous electrophysiological studies have made use of a piecewise linear characterization of voltage clamped neurons, which consists of a sequence of linear admittances computed at different voltage levels. In this paper, a fundamentally new theory is developed in two stages. First, analytical equations are derived for a multi-sinusoidal voltage clamp of a Hodgkin-Huxley type model to reveal the quadratic response at the ionic channel level. Second, the resulting behavior is generalized to a novel Hermitian neural operator, which uses an algebraic formulation capturing the entire quadratic behavior of a voltage clamped neuron. In addition, this operator can also be used for a nonlinear identification analysis directly applicable to experimental measurements. In this case, a Hermitian matrix of interactions is built with paired frequency probing measurements performed at specific harmonic and interactive output frequencies. More importantly, eigenanalysis of the neural operator provides a concise signature of the voltage dependent conductances determined by their particular distribution on the dendritic and somatic membrane regions of neurons. Finally, the theory is concretely illustrated by an analysis of an experimentally measured vestibular neuron, providing a remarkably compact description of the quadratic responses involved in the nonlinear processing underlying the control of eye position during head rotation, namely the neural integrator.

  8. A Dynamic Clamp on Every Rig.

    Science.gov (United States)

    Desai, Niraj S; Gray, Richard; Johnston, Daniel

    2017-01-01

    The dynamic clamp should be a standard part of every cellular electrophysiologist's toolbox. That it is not, even 25 years after its introduction, comes down to three issues: money, the disruption that adding dynamic clamp to an existing electrophysiology rig entails, and the technical prowess required of experimenters. These have been valid and limiting issues in the past, but no longer. Technological advances associated with the so-called maker movement render them moot. We demonstrate this by implementing a fast (∼100 kHz) dynamic clamp system using an inexpensive microcontroller (Teensy 3.6). The overall cost of the system is less than USD$100, and assembling it requires no prior electronics experience. Modifying it-for example, to add Hodgkin-Huxley-style conductances-requires no prior programming experience. The system works together with existing electrophysiology data acquisition systems (for Macintosh, Windows, and Linux); it does not attempt to supplant them. Moreover, the process of assembling, modifying, and using the system constitutes a useful pedagogical exercise for students and researchers with no background but an interest in electronics and programming. We demonstrate the system's utility by implementing conductances as fast as a transient sodium conductance and as complex as the Ornstein-Uhlenbeck conductances of the "point conductance" model of synaptic background activity.

  9. Time-Delay Artificial Neural Network Computing Models for Predicting Shelf Life of Processed Cheese

    OpenAIRE

    Sumit Goyal; Gyanendra Kumar Goyal

    2012-01-01

    This paper presents the capability of Time–delay artificial neural network models for predicting shelf life of processed cheese. Datasets were divided into two subsets (30 for training and 6 for validation). Models with single and multi layers were developed and compared with each other. Mean Square Error, Root Mean Square Error, Coefficient of Determination and Nash -
    Sutcliffo Coefficient were used as performance evaluators, Time- delay model predicted the shelf life of...

  10. MODELING OF EXTRUSION PROCESS USING RESPONSE SURFACE METHODOLOGY AND ARTIFICIAL NEURAL NETWORKS

    OpenAIRE

    NEELAM SHIHANI; B. K. KUMBHAR; MANOJ KULSHRESHTHA

    2006-01-01

    Artificial neural networks are a powerful tool for modeling of extrusion processing of food materials. Wheat flour and wheat– black soybean blend (95:5) were extruded in a single screw Brabender extruder with varying temperature (120 and 140 oC), dry basis moisture content (18 and 20%) and screw speed (156, 168, 180, 192 and 204 rpm). The specific mechanical energy, water absorption index, water solubility index, expansion ratio and sensory characteristics (crispness, hardness, appearance and...

  11. The topologic information processing by the artificial intellingence systems for the logic tasks' solving

    Directory of Open Access Journals (Sweden)

    Demyokhin V. V.

    2008-04-01

    Full Text Available The new method of parallel logic gates realization is described. The implementation of the parallel logic for a binary patterns considered on the basis of the topological information processing, used also in recognizing of visual images of single-layer systems of artificial intelligence. The estimates of the main parameters of TIP devices indicate that their performance can reach 1016 operations / sec and the amount of the structural elements is much less than in the known opto-logic devices.

  12. The use of artificial intelligence techniques to improve the multiple payload integration process

    Science.gov (United States)

    Cutts, Dannie E.; Widgren, Brian K.

    1992-01-01

    A maximum return of science and products with a minimum expenditure of time and resources is a major goal of mission payload integration. A critical component then, in successful mission payload integration is the acquisition and analysis of experiment requirements from the principal investigator and payload element developer teams. One effort to use artificial intelligence techniques to improve the acquisition and analysis of experiment requirements within the payload integration process is described.

  13. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  14. The Drosophila CLAMP protein associates with diverse proteins on chromatin.

    Science.gov (United States)

    Urban, Jennifer A; Urban, John M; Kuzu, Guray; Larschan, Erica N

    2017-01-01

    Gaining new insights into gene regulation involves an in-depth understanding of protein-protein interactions on chromatin. A powerful model for studying mechanisms of gene regulation is dosage compensation, a process that targets the X-chromosome to equalize gene expression between XY males and XX females. We previously identified a zinc finger protein in Drosophila melanogaster that plays a sex-specific role in targeting the Male-specific lethal (MSL) dosage compensation complex to the male X-chromosome, called the Chromatin-Linked Adapter for MSL Proteins (CLAMP). More recently, we established that CLAMP has non-sex-specific roles as an essential protein that regulates chromatin accessibility at promoters genome-wide. To identify associations between CLAMP and other factors in both male and female cells, we used two complementary mass spectrometry approaches. We demonstrate that CLAMP associates with the transcriptional regulator complex Negative Elongation Factor (NELF) in both sexes and determine that CLAMP reduces NELF recruitment to several target genes. In sum, we have identified many new CLAMP-associated factors and provide a resource for further study of this little understood essential protein.

  15. An ERP study of structural anomalies in native and semantic free artificial grammar: evidence for shared processing mechanisms.

    Science.gov (United States)

    Tabullo, Ángel; Sevilla, Yamila; Segura, Enrique; Zanutto, Silvano; Wainselboim, Alejandro

    2013-08-21

    Artificial grammars have been widely applied to the study of sequential learning in language, but few studies have directly compared the neural correlates of artificial and native grammar processing. In this study, we examined Event Related Potentials (ERPs) elicited by structural anomalies in semantic-free artificial grammar sequences and sentences in the subjects' native language (Spanish). Although ERPs differed during early stages, we observed similar posterior negativities (N400) and P600 effects in a late stage. We interpret these results as evidence of at least partially shared neural mechanisms for processing of language and artificial grammars. We suggest that in both the natural and artificial grammars, the N400 and P600 components we observed can be explained as the result of unfulfilled predictions about incoming stimuli. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Hot clamp design for LMFBR piping systems

    International Nuclear Information System (INIS)

    Kobayashi, T.; Tateishi, M.

    1990-01-01

    Thin wall large diameter piping for liquid metal fast breeder reactor plants can be subjected to significant thermal transients during reactor scrams. To reduce local thermal stresses, an insulted cold clamp was designed for the Fast Flux Test Facility and was also applied to some following prototype reactors. However, the cost minimization of LMFBR requires much simpler designs. This paper presents a hot clamp design concept, which uses standard clamp halves directly attached to the pipe surface with an initial gap. Combinations of flexible pipe and rigid clamp achieved a self-control effect on clamp induced pipe stresses due to the initial gap. A 3-D contact and inelastic history analysis were performed to verify the hot clamp concept. Considerations to reduce the initial stress at installation, to mitigate the clamp restraint on the pipe expansion during thermal shocks, and to maintain the pipe-clamp stiffness desired during a seismic event are discussed

  17. Hot clamp design for LMFBR piping systems

    International Nuclear Information System (INIS)

    Kobayashi, T.; Tateishi, M.

    1993-01-01

    Thin-wall, large-diameter piping for liquid metal fast breeder reactor (LMFBR) plants can be subjected to significant thermal transients during reactor scrams. To reduce local thermal stresses, an insulated cold clamp was designed for the fast flux test facility and was also applied to some prototype reactors thereafter. However, the cost minimization of LMFBR requires much simpler designs. This paper presents a hot clamp design concept, which uses standard clamp halves directly attached to the pipe surface leaving an initial gap. Combinations of flexible pipe and rigid clamp achieved a self-control effect on clamp-induced pipe stresses due to the initial gap. A 3-D contact and inelastic history analysis were performed to verify the hot clamp concept. Considerations to reduce the initial stress at installation, to mitigate the clamp restraint on the pipe expansion during thermal shocks, and to maintain the pipe-clamp stiffness desired during a seismic event were discussed

  18. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago

    2012-01-01

    This letter introduces a new series of multilevel (ML) converters based on the ML clamping concept. By applying this technique, a ML clamping unit (MCU) conveys additional levels for synthesizing the output waveforms of a diode-clampedML dc– ac power converter. The basic building block of the ML...... clamping scheme is the ML clamping cell, which is composed of a pair of dc sources associated with one single-pole/triple-throw type of switch arrangement. The number of series-connected ML-clamping cells will set the number of levels of the synthesized waveform. By depending on the MCU arrangements......, different converter configurations can be derived, namely, the common clamping and the modular types. Both approaches can be accomplished by employing classical three-level neutral-point-clamped (NPC) technology. Thus, the overall structure of the resultant converter is kept simple, wherein the number...

  19. Multifrequency Excitation of a Clamped-Clamped Microbeam

    KAUST Repository

    Jaber, Nizar R.

    2016-01-20

    We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

  20. The PCNA-RFC families of DNA clamps and clamp loaders.

    Science.gov (United States)

    Majka, Jerzy; Burgers, Peter M J

    2004-01-01

    The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.

  1. Bio-inspired Artificial Intelligence: А Generalized Net Model of the Regularization Process in MLP

    Directory of Open Access Journals (Sweden)

    Stanimir Surchev

    2013-10-01

    Full Text Available Many objects and processes inspired by the nature have been recreated by the scientists. The inspiration to create a Multilayer Neural Network came from human brain as member of the group. It possesses complicated structure and it is difficult to recreate, because of the existence of too many processes that require different solving methods. The aim of the following paper is to describe one of the methods that improve learning process of Artificial Neural Network. The proposed generalized net method presents Regularization process in Multilayer Neural Network. The purpose of verification is to protect the neural network from overfitting. The regularization is commonly used in neural network training process. Many methods of verification are present, the subject of interest is the one known as Regularization. It contains function in order to set weights and biases with smaller values to protect from overfitting.

  2. 21 CFR 870.4450 - Vascular clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and... CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular clamp is a surgical instrument used to occlude a blood vessel temporarily. (b) Classification. Class II...

  3. Artificial neural network associated to UV/Vis spectroscopy for monitoring bioreactions in biopharmaceutical processes.

    Science.gov (United States)

    Takahashi, Maria Beatriz; Leme, Jaci; Caricati, Celso Pereira; Tonso, Aldo; Fernández Núñez, Eutimio Gustavo; Rocha, José Celso

    2015-06-01

    Currently, mammalian cells are the most utilized hosts for biopharmaceutical production. The culture media for these cell lines include commonly in their composition a pH indicator. Spectroscopic techniques are used for biopharmaceutical process monitoring, among them, UV-Vis spectroscopy has found scarce applications. This work aimed to define artificial neural networks architecture and fit its parameters to predict some nutrients and metabolites, as well as viable cell concentration based on UV-Vis spectral data of mammalian cell bioprocess using phenol red in culture medium. The BHK-21 cell line was used as a mammalian cell model. Off-line spectra of supernatant samples taken from batches performed at different dissolved oxygen concentrations in two bioreactor configurations and with two pH control strategies were used to define two artificial neural networks. According to absolute errors, glutamine (0.13 ± 0.14 mM), glutamate (0.02 ± 0.02 mM), glucose (1.11 ± 1.70 mM), lactate (0.84 ± 0.68 mM) and viable cell concentrations (1.89 10(5) ± 1.90 10(5) cell/mL) were suitably predicted. The prediction error averages for monitored variables were lower than those previously reported using different spectroscopic techniques in combination with partial least squares or artificial neural network. The present work allows for UV-VIS sensor development, and decreases cost related to nutrients and metabolite quantifications.

  4. Effect of double flasking and investing methods on artificial teeth movement in complete dentures processing.

    Science.gov (United States)

    Sotto-Maior, Bruno S; Jóia, Fábio A; Meloto, Carolina B; Cury, Altair A Del Bel; Rizzatti-Barbosa, Célia M

    2012-06-01

    The aim of this study was to evaluate linear dimensional alterations of artificial teeth for complete dentures when using different investment and flasking techniques. Dimensional changes in the vertical dimension may occur owing to changes in artificial teeth positioning caused by different investing and flasking techniques. Thirty pairs of the complete dentures were manufactured and randomly divided into three groups (n = 10): (1) invested with type III stone in monomaxillary PVC flask; (2) invested with type III stone in bimaxillary PVC flask; and (3) invested with laboratory silicone in bimaxillary PVC flask. Dentures were polymerised by microwave, and 12 linear distances were measured before and after denture processing. Data were analysed by one-way anova, considering manufacturing technique as the study factor. Tukey's HSD was used as post hoc ANOVA (p = 0.05). Most of the linear distances were comparable for all groups. All transversal maxillary and mandibular distances were higher for group 1 compared with groups 2 and 3 (p investment material is shown to be the most effective method to reduce changes in artificial teeth positioning. © 2011 The Gerodontology Society and John Wiley & Sons A/S.

  5. Prodiag--a hybrid artificial intelligence based reactor diagnostic system for process faults

    International Nuclear Information System (INIS)

    Reifman, J.; Wei, T.Y.C.; Vitela, J.E.; Applequist, C. A.; Chasensky, T.M.

    1996-01-01

    Commonwealth Research Corporation (CRC) and Argonne National Laboratory (ANL) are collaborating on a DOE-sponsored Cooperative Research and Development Agreement (CRADA), project to perform feasibility studies on a novel approach to Artificial Intelligence (Al) based diagnostics for component faults in nuclear power plants. Investigations are being performed in the construction of a first-principles physics-based plant level process diagnostic expert system (ES) and the identification of component-level fault patterns through operating component characteristics using artificial neural networks (ANNs). The purpose of the proof-of-concept project is to develop a computer-based system using this Al approach to assist process plant operators during off-normal plant conditions. The proposed computer-based system will use thermal hydraulic (T-H) signals complemented by other non-T-H signals available in the data stream to provide the process operator with the component which most likely caused the observed process disturbance.To demonstrate the scale-up feasibility of the proposed diagnostic system it is being developed for use with the Chemical Volume Control System (CVCS) of a nuclear power plant. A full-scope operator training simulator representing the Commonwealth Edison Braidwood nuclear power plant is being used both as the source of development data and as the means to evaluate the advantages of the proposed diagnostic system. This is an ongoing multi-year project and this paper presents the results to date of the CRADA phase

  6. The Virtual UNICOS Process Expert: integration of Artificial Intelligence tools in Control Systems

    CERN Multimedia

    Vilches Calvo, I; Barillere, R

    2009-01-01

    UNICOS is a CERN framework to produce control applications. It provides operators with ways to interact with all process items from the most simple (e.g. I/O channels) to the most abstract objects (e.g. a part of the plant). This possibility of fine grain operation is particularly useful to recover from abnormal situations if operators have the required knowledge. The Virtual UNICOS Process Expert project aims at providing operators with means to handle difficult operation cases for which the intervention of process experts is usually requested. The main idea of project is to use the openness of the UNICOS-based applications to integrate tools (e.g. Artificial Intelligence tools) which will act as Process Experts to analyze complex situations, to propose and to execute smooth recovery procedures.

  7. Electrostatic Interactions at the Dimer Interface Stabilize the E. coli β Sliding Clamp.

    Science.gov (United States)

    Purohit, Anirban; England, Jennifer K; Douma, Lauren G; Tondnevis, Farzaneh; Bloom, Linda B; Levitus, Marcia

    2017-08-22

    Sliding clamps are ring-shaped oligomeric proteins that encircle DNA and associate with DNA polymerases for processive DNA replication. The dimeric Escherichia coli β-clamp is closed in solution but must adopt an open conformation to be assembled onto DNA by a clamp loader. To determine what factors contribute to the stability of the dimer interfaces in the closed conformation and how clamp dynamics contribute to formation of the open conformation, we identified conditions that destabilized the dimer and measured the effects of these conditions on clamp dynamics. We characterized the role of electrostatic interactions in stabilizing the β-clamp interface. Increasing salt concentration results in decreased dimer stability and faster subunit dissociation kinetics. The equilibrium dissociation constant of the dimeric clamp varies with salt concentration as predicted by simple charge-screening models, indicating that charged amino acids contribute to the remarkable stability of the interface at physiological salt concentrations. Mutation of a charged residue at the interface (Arg-103) weakens the interface significantly, whereas effects are negligible when a hydrophilic (Ser-109) or a hydrophobic (Ile-305) amino acid is mutated instead. It has been suggested that clamp opening by the clamp loader takes advantage of spontaneous opening-closing fluctuations at the clamp's interface, but our time-resolved fluorescence and fluorescence correlation experiments rule out conformational fluctuations that lead to a significant fraction of open states. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  8. Natural and artificial aging response of semisolid metal processed Al–Si–Mg alloy A356

    CSIR Research Space (South Africa)

    Moller, H

    2007-12-01

    Full Text Available useful tool to gauge the effect of changes to the heat treatment cycles of SSM HPDC A356. The best QI in this study was obtained using a short solution heat treatment of only 1 h at 540uC, no natural aging and artificial aging at 180uC for 1 h. 5.... Sahoo, J. H. Sokolowski, P. Burke and M. Hart: Proc. 132th TMS Annual Conf., San Diego, CA, USA, March 2003, TMS, 983–989. 15. M. Badiali, C. J. Davidson, J. R. Griffiths and A. Zanada: Proc. 6th Int. Conf. on ‘Semi-solid processing of alloys...

  9. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  10. The RFC clamp loader: structure and function.

    Science.gov (United States)

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  11. The RFC Clamp Loader: Structure and Function

    Science.gov (United States)

    O'Donnell, Mike

    2013-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction. PMID:22918590

  12. Artificial neural network approach to modeling of alcoholic fermentation of thick juice from sugar beet processing

    Directory of Open Access Journals (Sweden)

    Jokić Aleksandar I.

    2012-01-01

    Full Text Available In this paper the bioethanol production in batch culture by free Saccharomyces cerevisiae cells from thick juice as intermediate product of sugar beet processing was examined. The obtained results suggest that it is possible to decrease fermentation time for the cultivation medium based on thick juice with starting sugar content of 5-15 g kg-1. For the fermentation of cultivation medium based on thick juice with starting sugar content of 20 and 25 g kg-1 significant increase in ethanol content was attained during the whole fermentation process, resulting in 12.51 and 10.95 dm3 m-3 ethanol contents after 48 h, respectively. Other goals of this work were to investigate the possibilities for experimental results prediction using artificial neural networks (ANNs and to find its optimal topology. A feed-forward back-propagation artificial neural network was used to test the hypothesis. As input variables fermentation time and starting sugar content were used. Neural networks had one output value, ethanol content, yeast cell number or sugar content. There was one hidden layer and the optimal number of neurons was found to be nine for all selected network outputs. In this study transfer function was tansig and the selected learning rule was Levenberg-Marquardt. Results suggest that artificial neural networks are good prediction tool for selected network outputs. It was found that experimental results are in very good agreement with computed ones. The coefficient of determination (the R-squared was found to be 0.9997, 0.9997 and 0.9999 for ethanol content, yeast cell number and sugar content, respectively.

  13. A clamp-like biohybrid catalyst for DNA oxidation

    NARCIS (Netherlands)

    van Dongen, S.F.M.; Clerx, J.; Norgaard, K.; Bloemberg, T.G.; Cornelissen, Jeroen Johannes Lambertus Maria; Trakselis, M.A.; Nelson, S.W.; Benkovic, S.J.; Rowan, A.E.; Nolte, R.J.M.

    2013-01-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric)

  14. Processes engaged in the persistence in atmosphere of previously deposited artificial radionuclides

    International Nuclear Information System (INIS)

    Piga, Damien

    2010-01-01

    Since 1959, atmospheric sampling stations of the environmental radioactivity permanent observatory measure both natural and artificial radioactivity in ambient air. Nowadays, Cs-137 (30.07 years), an artificial radionuclide mainly issue from atmospheric weapons tests and several accidents, is still measured at trace level in the lower atmosphere although there is no significant release anymore. The aim of this study was to identify and characterize the processes which explain this persistence. Areas highly contaminated by Chernobylsk accident are the major contributors to the Cs-137 atmospheric persistence in France. In these areas, wildfires are the most significant resuspension processes during the dry season and can lead to long range transport events. Around 1013 Bq of Cs-137 are yearly resuspended by this process. In connection with significant increases of total suspended particles, Sahara is the second area involved in the atmospheric Cs-137 persistence due to dust transport events. The whole of these events has a mean contribution of around 1/3 of the Cs-137 background level at the French scale. The last identified process is the wood burning during winter. Even if its emission factor is low, spatial extent of source areas and quantities used at the season scale makes wood burning a significant process compared to ambient trace levels. At the French scale, around 1011 Bq of Cs-137 are yearly resuspended by this process. During this season, the decrease of ventilation conditions in the lower atmosphere leads to an increase of the background level whereas significant increases are due to long range transport events from Eastern Europe

  15. Dynamic analysis of slender launching system connected by clamp band joint using harmonic balance method

    International Nuclear Information System (INIS)

    Qin, Z Y; Yan, S Z; Chu, F L

    2013-01-01

    Clamp band joints are widely used to fasten spacecrafts onto launching systems. Due to the unilateral constraints and the frictional slippage at the joint interface, clamp band joints may bring nonlinearity into launching systems during launching process. In this paper, the dynamics of a slender launching system with clamp band joint is investigated using harmonic balance method. Firstly, the formulas for the joint stiffness of the clamp band joint are proposed. Then, the finite element model for the launch vehicle and the spacecraft connected by the clamp band joint is developed, where the clamp band joint is represented by a massless beam element. Finally, harmonic balance method is applied to calculate the steady state response of the launching system

  16. MODELING OF EXTRUSION PROCESS USING RESPONSE SURFACE METHODOLOGY AND ARTIFICIAL NEURAL NETWORKS

    Directory of Open Access Journals (Sweden)

    NEELAM SHIHANI

    2006-06-01

    Full Text Available Artificial neural networks are a powerful tool for modeling of extrusion processing of food materials. Wheat flour and wheat– black soybean blend (95:5 were extruded in a single screw Brabender extruder with varying temperature (120 and 140 oC, dry basis moisture content (18 and 20% and screw speed (156, 168, 180, 192 and 204 rpm. The specific mechanical energy, water absorption index, water solubility index, expansion ratio and sensory characteristics (crispness, hardness, appearance and overall acceptability were measured. Well expanded products could be obtained from wheat flour as well as the blend of wheat– black soybean. The results showed that artificial neural network (ANN models performed better than the response surface methodology (RSM models in describing the extrusion process and characteristics of the extruded product in terms of specific mechanical energy requirement, expansion ratio, water absorption index, water solubility index as well the sensory characteristics. The ANN models were better than RSM models both in case of the individual as well as the pooled data of wheat flour and wheat- black soybean extrusion.

  17. Using the artificial neural network to control the steam turbine heating process

    International Nuclear Information System (INIS)

    Nowak, Grzegorz; Rusin, Andrzej

    2016-01-01

    Highlights: • Inverse Artificial Neural Network has a potential to control the start-up process of a steam turbine. • Two serial neural networks made it possible to model the rotor stress based of steam parameters. • An ANN with feedback enables transient stress modelling with good accuracy. - Abstract: Due to the significant share of renewable energy sources (RES) – wind farms in particular – in the power sector of many countries, power generation systems become sensitive to variable weather conditions. Under unfavourable changes in weather, ensuring required energy supplies involves hasty start-ups of conventional steam power units whose operation should be characterized by higher and higher flexibility. Controlling the process of power engineering machinery operation requires fast predictive models that will make it possible to analyse many parallel scenarios and select the most favourable one. This approach is employed by the algorithm for the inverse neural network control presented in this paper. Based on the current thermal state of the turbine casing, the algorithm controls the steam temperature at the turbine inlet to keep both the start-up rate and the safety of the machine at the allowable level. The method used herein is based on two artificial neural networks (ANN) working in series.

  18. Mechanism of ATP-driven PCNA clamp loading by S. cerevisiae RFC.

    Science.gov (United States)

    Chen, Siying; Levin, Mikhail K; Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2009-05-08

    Circular clamps tether polymerases to DNA, serving as essential processivity factors in genome replication, and function in other critical cellular processes as well. Clamp loaders catalyze clamp assembly onto DNA, and the question of how these proteins construct a topological link between a clamp and DNA, especially the mechanism by which ATP is utilized for the task, remains open. Here we describe pre-steady-state analysis of ATP hydrolysis, proliferating cell nuclear antigen (PCNA) clamp opening, and DNA binding by Saccharomyces cerevisiae replication factor C (RFC), and present the first kinetic model of a eukaryotic clamp-loading reaction validated by global data analysis. ATP binding to multiple RFC subunits initiates a slow conformational change in the clamp loader, enabling it to bind and open PCNA and to bind DNA as well. PCNA opening locks RFC into an active state, and the resulting RFC.ATP.PCNA((open)) intermediate is ready for the entry of DNA into the clamp. DNA binding commits RFC to ATP hydrolysis, which is followed by PCNA closure and PCNA.DNA release. This model enables quantitative understanding of the multistep mechanism of a eukaryotic clamp loader and furthermore facilitates comparative analysis of loaders from diverse organisms.

  19. Using artificial neural networks to model extrusion processes for the manufacturing of polymeric micro-tubes

    International Nuclear Information System (INIS)

    Mekras, N; Artemakis, I

    2012-01-01

    In this paper a methodology and an application example are presented aiming to show how Artificial Neural Networks (ANNs) can be used to model manufacturing processes when mathematical models are missing or are not applicable e.g. due to the micro- and nano-scaling, due to non-conventional processes, etc. Besides the ANNs methodology, the results of a Software System developed will be presented, which was used to create ANNs models for micro and nano manufacturing processes. More specifically results of a specific application example will be presented, concerning the modeling of extrusion processes for polymeric micro-tubes. ANNs models are capable for modeling manufacturing processes as far as adequate experimental and/or historical data of processes' inputs and outputs are available for their training. The POLYTUBES ANNs models have been trained and tested with experimental data records of process' inputs and outputs concerning a micro-extrusion process of polymeric micro-tubes for several materials such as: COC, PC, PET, PETG, PP and PVDF. The main ANN model of the extrusion application example has 3 inputs and 9 outputs. The inputs are: tube's inner and outer diameters, and the material density. The model outputs are 9 process parameters, which correspond to the specific inputs e.g. process temperature, die inner and outer diameters, extrusion pressure, draw speed etc. The training of the ANN model was completed, when the errors for the model's outputs, which expressed the difference between the training target values and the ANNs outputs, were minimized to acceptable levels. After the training, the micro-extrusion ANN is capable to simulate the process and can be used to calculate model's outputs, which are the process parameters for any new set of inputs. By this way a satisfactory functional approximation of the whole process is achieved. This research work has been supported by the EU FP7 NMP project POLYTUBES.

  20. An Artificial Bee Colony Algorithm for the Job Shop Scheduling Problem with Random Processing Times

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2011-09-01

    Full Text Available Due to the influence of unpredictable random events, the processing time of each operation should be treated as random variables if we aim at a robust production schedule. However, compared with the extensive research on the deterministic model, the stochastic job shop scheduling problem (SJSSP has not received sufficient attention. In this paper, we propose an artificial bee colony (ABC algorithm for SJSSP with the objective of minimizing the maximum lateness (which is an index of service quality. First, we propose a performance estimate for preliminary screening of the candidate solutions. Then, the K-armed bandit model is utilized for reducing the computational burden in the exact evaluation (through Monte Carlo simulation process. Finally, the computational results on different-scale test problems validate the effectiveness and efficiency of the proposed approach.

  1. Using dual-task methodology to dissociate automatic from nonautomatic processes involved in artificial grammar learning.

    Science.gov (United States)

    Hendricks, Michelle A; Conway, Christopher M; Kellogg, Ronald T

    2013-09-01

    Previous studies have suggested that both automatic and intentional processes contribute to the learning of grammar and fragment knowledge in artificial grammar learning (AGL) tasks. To explore the relative contribution of automatic and intentional processes to knowledge gained in AGL, we utilized dual-task methodology to dissociate automatic and intentional grammar- and fragment-based knowledge in AGL at both acquisition and at test. Both experiments used a balanced chunk strength grammar to assure an equal proportion of fragment cues (i.e., chunks) in grammatical and nongrammatical test items. In Experiment 1, participants engaged in a working memory dual-task either during acquisition, test, or both acquisition and test. The results showed that participants performing the dual-task during acquisition learned the artificial grammar as well as the single-task group, presumably by relying on automatic learning mechanisms. A working memory dual-task at test resulted in attenuated grammar performance, suggesting a role for intentional processes for the expression of grammatical learning at test. Experiment 2 explored the importance of perceptual cues by changing letters between the acquisition and test phase; unlike Experiment 1, there was no significant learning of grammatical information for participants under dual-task conditions in Experiment 2, suggesting that intentional processing is necessary for successful acquisition and expression of grammar-based knowledge under transfer conditions. In sum, it appears that some aspects of learning in AGL are indeed relatively automatic, although the expression of grammatical information and the learning of grammatical patterns when perceptual similarity is eliminated both appear to require explicit resources. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  2. Modeling of steam distillation mechanism during steam injection process using artificial intelligence.

    Science.gov (United States)

    Daryasafar, Amin; Ahadi, Arash; Kharrat, Riyaz

    2014-01-01

    Steam distillation as one of the important mechanisms has a great role in oil recovery in thermal methods and so it is important to simulate this process experimentally and theoretically. In this work, the simulation of steam distillation is performed on sixteen sets of crude oil data found in the literature. Artificial intelligence (AI) tools such as artificial neural network (ANN) and also adaptive neurofuzzy interference system (ANFIS) are used in this study as effective methods to simulate the distillate recoveries of these sets of data. Thirteen sets of data were used to train the models and three sets were used to test the models. The developed models are highly compatible with respect to input oil properties and can predict the distillate yield with minimum entry. For showing the performance of the proposed models, simulation of steam distillation is also done using modified Peng-Robinson equation of state. Comparison between the calculated distillates by ANFIS and neural network models and also equation of state-based method indicates that the errors of the ANFIS model for training data and test data sets are lower than those of other methods.

  3. Analysis of Artificial Neural Network Backpropagation Using Conjugate Gradient Fletcher Reeves In The Predicting Process

    Science.gov (United States)

    Wanto, Anjar; Zarlis, Muhammad; Sawaluddin; Hartama, Dedy

    2017-12-01

    Backpropagation is a good artificial neural network algorithm used to predict, one of which is to predict the rate of Consumer Price Index (CPI) based on the foodstuff sector. While conjugate gradient fletcher reeves is a suitable optimization method when juxtaposed with backpropagation method, because this method can shorten iteration without reducing the quality of training and testing result. Consumer Price Index (CPI) data that will be predicted to come from the Central Statistics Agency (BPS) Pematangsiantar. The results of this study will be expected to contribute to the government in making policies to improve economic growth. In this study, the data obtained will be processed by conducting training and testing with artificial neural network backpropagation by using parameter learning rate 0,01 and target error minimum that is 0.001-0,09. The training network is built with binary and bipolar sigmoid activation functions. After the results with backpropagation are obtained, it will then be optimized using the conjugate gradient fletcher reeves method by conducting the same training and testing based on 5 predefined network architectures. The result, the method used can increase the speed and accuracy result.

  4. Microchip amplifier for in vitro, in vivo, and automated whole cell patch-clamp recording.

    Science.gov (United States)

    Harrison, Reid R; Kolb, Ilya; Kodandaramaiah, Suhasa B; Chubykin, Alexander A; Yang, Aimei; Bear, Mark F; Boyden, Edward S; Forest, Craig R

    2015-02-15

    Patch clamping is a gold-standard electrophysiology technique that has the temporal resolution and signal-to-noise ratio capable of reporting single ion channel currents, as well as electrical activity of excitable single cells. Despite its usefulness and decades of development, the amplifiers required for patch clamping are expensive and bulky. This has limited the scalability and throughput of patch clamping for single-ion channel and single-cell analyses. In this work, we have developed a custom patch-clamp amplifier microchip that can be fabricated using standard commercial silicon processes capable of performing both voltage- and current-clamp measurements. A key innovation is the use of nonlinear feedback elements in the voltage-clamp amplifier circuit to convert measured currents into logarithmically encoded voltages, thereby eliminating the need for large high-valued resistors, a factor that has limited previous attempts at integration. Benchtop characterization of the chip shows low levels of current noise [1.1 pA root mean square (rms) over 5 kHz] during voltage-clamp measurements and low levels of voltage noise (8.2 μV rms over 10 kHz) during current-clamp measurements. We demonstrate the ability of the chip to perform both current- and voltage-clamp measurement in vitro in HEK293FT cells and cultured neurons. We also demonstrate its ability to perform in vivo recordings as part of a robotic patch-clamping system. The performance of the patch-clamp amplifier microchip compares favorably with much larger commercial instrumentation, enabling benchtop commoditization, miniaturization, and scalable patch-clamp instrumentation. Copyright © 2015 the American Physiological Society.

  5. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery.

    Science.gov (United States)

    Vriens, Bianca H R; Pol, Robert A; Hulsebos, Robin G; van Det, Rob J; van der Palen, Job; Zeebregts, Clark J; Geelkerken, Robert H

    2015-09-01

    To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inlay clamp and marked with an hemoclip. The number of pre-existing atherosclerotic segments, clamp force, and clamp time were recorded and the occurrence of a stenosis at the clamp site was determined. After a mean follow-up of 83 months, a significant stenosis was confirmed at 23 of the 178 clamp sites (12.9%; 95% confidence interval 8.4 to 18.8). The mean number of pre-existing atherosclerotic segments (P = .28) and the mean clamp force (P = .55) was similar between the groups with and without a stenosis. There was a significant difference regarding clamp time between the group with and without a stenosis (38 minutes and 26 minutes, P = .001). Arterial clamping, even with the Fogarty-Soft-Inlay clamp, can lead to clamp stenosis and seems to be related to the duration of clamping, but not to pre-existent atherosclerotic burden. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. How does clamping pressure influence actuation performance of soft ionic polymer–metal composites?

    International Nuclear Information System (INIS)

    Moeinkhah, Hossein; Jung, Jin-Young; Jeon, Jin-Han; Park, K C; Oh, Il-Kwon; Akbarzadeh, Ali; Rezaeepazhand, Jalil

    2013-01-01

    The effect of clamping pressure on the actuation performance of ionic polymer–metal composite (IPMC) actuators is newly investigated by carefully considering changes of mechanical stiffness and electrical resistance due to the interfacial contacts between the IPMC and clamping devices. During the clamping process, the soft ionic exchangeable polymer membrane will be squeezed along the thickness direction in the clamping area, resulting in a change of the mechanical stiffness of the cantilevered IPMCs. Also, the electrical contact resistance between two electrodes of the IPMC and the clamping device will be greatly changed according to the change of clamping pressures. Present experimental results show that clamping pressures between the IPMC and the clamping device will strongly affect the actuation performance of the IPMC actuators. An exact electro-mechanical model is developed to fully describe dynamics of the IPMC actuators by considering structural damping, hydrodynamic loading and electro-mechanical force. This study shows that there exists an optimal clamping pressure to obtain the largest bending deformation of the IPMC actuator because of a trade-off between mechanical stiffness and electrical contact resistance. (paper)

  7. To clamp or not to clamp? Long-term functional outcomes for elective off-clamp laparoscopic partial nephrectomy.

    Science.gov (United States)

    Shah, Paras H; George, Arvin K; Moreira, Daniel M; Alom, Manaf; Okhunov, Zhamshid; Salami, Simpa; Waingankar, Nikhil; Schwartz, Michael J; Vira, Manish A; Richstone, Lee; Kavoussi, Louis R

    2016-02-01

    To evaluate whether elective off-clamp laparoscopic partial nephrectomy (LPN) affords long-term renal functional benefit compared with the on-clamp approach. This is a retrospective review of patients who underwent elective LPN between 2006 and 2011. Patients were followed longitudinally for up to 5 years. In all, 315 patients with radiographic evidence of a solitary renal mass and normal-appearing contralateral kidney underwent elective LPN; 209 were performed on-clamp vs 106 off-clamp. One patient who required conversion from LPN to open PN was excluded from the study. Additionally, four patients in the on-clamp cohort who underwent subsequent radical nephrectomy for local-regional recurrence were excluded from longitudinal functional evaluation after their procedure. The primary objective was to evaluate differences in postoperative estimated glomerular filtration rate (eGFR) between hilar clamping groups. Subgroup analyses were performed for patients with clamp times >30 min and those with baseline renal insufficiency (eGFR clamp and off-clamp cohorts (80.7 vs 84.1 mL/min/1.73m(2) , P > 0.05). Univariable and multivariable analyses did not show significant differences in postoperative eGFR between both groups among all-comers, those with clamp times >30 min, and patients with baseline renal insufficiency. Risk of chronic kidney disease was not diminished by the off-clamp approach with up to 5 years of follow-up. Progressive recovery of renal function after hilar clamping in the elective setting eclipses short-term functional benefit achieved with off-clamp LPN by 6 months; there was no significant difference in eGFR or the percentage incidence of chronic kidney disease between the on-clamp and off-clamp cohorts with up to 5 years follow-up. As such, eliminating transient ischaemia during elective LPN does not confer clinical benefit. © 2015 The Authors BJU International © 2015 BJU International Published by John Wiley & Sons Ltd.

  8. Development of automatic radiographic inspection system using digital image processing and artificial intelligence

    International Nuclear Information System (INIS)

    Itoga, Kouyu; Sugimoto, Koji; Michiba, Koji; Kato, Yuhei; Sugita, Yuji; Onda, Katsuhiro.

    1991-01-01

    The application of computers to welding inspection is expanding rapidly. The classification of the application is the collection, analysis and processing of data, the graphic display of results, the distinction of the kinds of defects and the evaluation of the harmufulness of defects and the judgement of acceptance or rejection. The application of computer techniques to the automation of data collection was realized at the relatively early stage. Data processing and the graphic display of results are the techniques in progress now, and the application of artificial intelligence to the distinction of the kinds of defects and the evaluation of harmfulness is expected to expand rapidly. In order to computerize radiographic inspection, the abilities of image processing technology and knowledge engineering must be given to computers. The object of this system is the butt joints by arc welding of the steel materials of up to 30 mm thickness. The digitizing transformation of radiographs, the distinction and evaluation of transmissivity and gradation by image processing, and only as for those, of which the picture quality satisfies the standard, the extraction of defect images, their display, the distinction of the kinds and the final judgement are carried out. The techniques of image processing, the knowledge for distinguishing the kinds of defects and the concept of the practical system are reported. (K.I.)

  9. Artificial Intelligence Tools for Scaling Up of High Shear Wet Granulation Process.

    Science.gov (United States)

    Landin, Mariana

    2017-01-01

    The results presented in this article demonstrate the potential of artificial intelligence tools for predicting the endpoint of the granulation process in high-speed mixer granulators of different scales from 25L to 600L. The combination of neurofuzzy logic and gene expression programing technologies allowed the modeling of the impeller power as a function of operation conditions and wet granule properties, establishing the critical variables that affect the response and obtaining a unique experimental polynomial equation (transparent model) of high predictability (R 2 > 86.78%) for all size equipment. Gene expression programing allowed the modeling of the granulation process for granulators of similar and dissimilar geometries and can be improved by implementing additional characteristics of the process, as composition variables or operation parameters (e.g., batch size, chopper speed). The principles and the methodology proposed here can be applied to understand and control manufacturing process, using any other granulation equipment, including continuous granulation processes. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  10. Artificial neural network (ANN) approach for modeling Zn(II) adsorption in batch process

    Energy Technology Data Exchange (ETDEWEB)

    Yildiz, Sayiter [Engineering Faculty, Cumhuriyet University, Sivas (Turkmenistan)

    2017-09-15

    Artificial neural networks (ANN) were applied to predict adsorption efficiency of peanut shells for the removal of Zn(II) ions from aqueous solutions. Effects of initial pH, Zn(II) concentrations, temperature, contact duration and adsorbent dosage were determined in batch experiments. The sorption capacities of the sorbents were predicted with the aid of equilibrium and kinetic models. The Zn(II) ions adsorption onto peanut shell was better defined by the pseudo-second-order kinetic model, for both initial pH, and temperature. The highest R{sup 2} value in isotherm studies was obtained from Freundlich isotherm for the inlet concentration and from Temkin isotherm for the sorbent amount. The high R{sup 2} values prove that modeling the adsorption process with ANN is a satisfactory approach. The experimental results and the predicted results by the model with the ANN were found to be highly compatible with each other.

  11. The Role of Simple Semantics in the Process of Artificial Grammar Learning.

    Science.gov (United States)

    Öttl, Birgit; Jäger, Gerhard; Kaup, Barbara

    2017-10-01

    This study investigated the effect of semantic information on artificial grammar learning (AGL). Recursive grammars of different complexity levels (regular language, mirror language, copy language) were investigated in a series of AGL experiments. In the with-semantics condition, participants acquired semantic information prior to the AGL experiment; in the without-semantics control condition, participants did not receive semantic information. It was hypothesized that semantics would generally facilitate grammar acquisition and that the learning benefit in the with-semantics conditions would increase with increasing grammar complexity. Experiment 1 showed learning effects for all grammars but no performance difference between conditions. Experiment 2 replicated the absence of a semantic benefit for all grammars even though semantic information was more prominent during grammar acquisition as compared to Experiment 1. Thus, we did not find evidence for the idea that semantics facilitates grammar acquisition, which seems to support the view of an independent syntactic processing component.

  12. Artificial intelligence for the modeling and control of combustion processes: a review

    Energy Technology Data Exchange (ETDEWEB)

    Kalogirou, S.A. [Higher Technical Inst., Nicosia, Cyprus (Greece). Dept. of Mechanical Engineering

    2003-07-01

    Artificial intelligence (AI) systems are widely accepted as a technology offering an alternative way to tackle complex and ill-defined problems. They can learn from examples, are fault tolerant in the sense that they are able to handle noisy and incomplete data, are able to deal with non-linear problems, and once trained can perform prediction and generalization at high speed. They have been used in diverse applications in control, robotics, pattern recognition, forecasting, medicine, power systems, manufacturing, optimization, signal processing, and social/psychological sciences. They are particularly useful in system modeling such as in implementing complex mappings and system identification. Al systems comprise areas like, expert systems, artificial neural networks, genetic algorithms, fuzzy logic and various hybrid systems, which combine two or more techniques. The major objective of this paper is to illustrate how Al techniques might play an important role in modeling and prediction of the performance and control of combustion process. The paper outlines an understanding of how AI systems operate by way of presenting a number of problems in the different disciplines of combustion engineering. The various applications of AI are presented in a thematic rather than a chronological or any other order. Problems presented include two main areas: combustion systems and internal combustion (IC) engines. Combustion systems include boilers, furnaces and incinerators modeling and emissions prediction, whereas, IC engines include diesel and spark ignition engines and gas engines modeling and control. Results presented in this paper, are testimony to the potential of Al as a design tool in many areas of combustion engineering. (author)

  13. Artificial intelligence for the modeling and control of combustion processes: a review

    Energy Technology Data Exchange (ETDEWEB)

    Soteris A. Kalogirou, [Higher Technical Institute, Nicosia (Cyprus). Department of Mechanical Engineering

    2003-07-01

    Artificial intelligence (AI) systems are widely accepted as a technology offering an alternative way to tackle complex and ill-defined problems. They can learn from examples, are fault tolerant in the sense that they are able to handle noisy and incomplete data, are able to deal with non-linear problems, and once trained can perform prediction and generalization at high speed. They have been used in diverse applications in control, robotics, pattern recognition, forecasting, medicine, power systems, manufacturing, optimization, signal processing, and social/psychological sciences. They are particularly useful in system modeling such as in implementing complex mappings and system identification. AI systems comprise areas like, expert systems, artificial neural networks, genetic algorithms, fuzzy logic and various hybrid systems, which combine two or more techniques. The major objective of this paper is to illustrate how AI techniques might play an important role in modeling and prediction of the performance and control of combustion process. The paper outlines an understanding of how AI systems operate by way of presenting a number of problems in the different disciplines of combustion engineering. The various applications of AI are presented in a thematic rather than a chronological or any other order. Problems presented include two main areas: combustion systems and internal combustion (IC) engines. Combustion systems include boilers, furnaces and incinerators modeling and emissions prediction, whereas, IC engines include diesel and spark ignition engines and gas engines modeling and control. Results presented in this paper, are testimony to the potential of AI as a design tool in many areas of combustion engineering. 109 refs., 31 figs., 11 tabs.

  14. Artificial intelligence versus statistical modeling and optimization of continuous bead milling process for bacterial cell lysis

    Directory of Open Access Journals (Sweden)

    Shafiul Haque

    2016-11-01

    Full Text Available AbstractFor a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD was studied in a continuous bead milling process. A full factorial Response Surface Model (RSM design was employed and compared to Artificial Neural Networks coupled with Genetic Algorithm (ANN-GA. Significant process variables, cell slurry feed rate (A, bead load (B, cell load (C and run time (D, were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v, cell loading OD600 nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN coupled with GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h: 258.08, bead loading (%, v/v: 80%, cell loading (OD600 nm: 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN in combination with evolutionary optimization (GA for representing undefined biological functions which is the case for common industrial processes involving biological moieties.

  15. Fate of artificial sweeteners through wastewater treatment plants and water treatment processes.

    Science.gov (United States)

    Li, Shaoli; Ren, Yuhang; Fu, Yingying; Gao, Xingsheng; Jiang, Cong; Wu, Gang; Ren, Hongqiang; Geng, Jinju

    2018-01-01

    Five full-scale wastewater treatment plants (WWTPs) in China using typical biodegradation processes (SBR, oxidation ditch, A2/O) were selected to assess the removal of four popular artificial sweeteners (ASs). All four ASs (acesulfame (ACE), sucralose (SUC), cyclamate (CYC) and saccharin (SAC)) were detected, ranging from 0.43 to 27.34μg/L in the influent. Higher concentrations of ASs were measured in winter. ACE could be partly removed by 7.11-50.76% through biodegradation and especially through the denitrifying process. The A2/O process was the most efficient at biodegrading ASs. Adsorption (by granular activated carbon (GAC) and magnetic resin) and ultraviolet radiation-based advanced oxidation processes (UV/AOPs) were evaluated to remove ASs in laboratory-scale tests. The amounts of resin adsorbed were 3.33-18.51 times more than those of GAC except for SUC. The adsorption ability of resin decreased in the order of SAC > ACE > CYC > SUC in accordance with the pKa. Degradation of ASs followed pseudo-first-order kinetics in UV/H2O2 and UV/PDS. When applied to the secondary effluent, ASs could be degraded from 30.87 to 99.93% using UV/PDS in 30 minutes and UV/PDS was more efficient and economic.

  16. Fate of artificial sweeteners through wastewater treatment plants and water treatment processes.

    Directory of Open Access Journals (Sweden)

    Shaoli Li

    Full Text Available Five full-scale wastewater treatment plants (WWTPs in China using typical biodegradation processes (SBR, oxidation ditch, A2/O were selected to assess the removal of four popular artificial sweeteners (ASs. All four ASs (acesulfame (ACE, sucralose (SUC, cyclamate (CYC and saccharin (SAC were detected, ranging from 0.43 to 27.34μg/L in the influent. Higher concentrations of ASs were measured in winter. ACE could be partly removed by 7.11-50.76% through biodegradation and especially through the denitrifying process. The A2/O process was the most efficient at biodegrading ASs. Adsorption (by granular activated carbon (GAC and magnetic resin and ultraviolet radiation-based advanced oxidation processes (UV/AOPs were evaluated to remove ASs in laboratory-scale tests. The amounts of resin adsorbed were 3.33-18.51 times more than those of GAC except for SUC. The adsorption ability of resin decreased in the order of SAC > ACE > CYC > SUC in accordance with the pKa. Degradation of ASs followed pseudo-first-order kinetics in UV/H2O2 and UV/PDS. When applied to the secondary effluent, ASs could be degraded from 30.87 to 99.93% using UV/PDS in 30 minutes and UV/PDS was more efficient and economic.

  17. Vacuum Thermoforming Process: An Approach to Modeling and Optimization Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Wanderson de Oliveira Leite

    2018-02-01

    Full Text Available In the vacuum thermoforming process, the group effects of the processing parameters, when related to the minimizing of the product deviations set, have conflicting and non-linear values which make their mathematical modelling complex and multi-objective. Therefore, this work developed models of prediction and optimization using artificial neural networks (ANN, having the processing parameters set as the networks’ inputs and the deviations group as the outputs and, furthermore, an objective function of deviation minimization. For the ANN data, samples were produced in experimental tests of a product standard in polystyrene, through a fractional factorial design (2k-p. Preliminary computational studies were carried out with various ANN structures and configurations with the test data until reaching satisfactory models and, afterwards, multi-criteria optimization models were developed. The validation tests were developed with the models’ predictions and solutions showed that the estimates for them have prediction errors within the limit of values found in the samples produced. Thus, it was demonstrated that, within certain limits, the ANN models are valid to model the vacuum thermoforming process using multiple parameters for the input and objective, by means of reduced data quantity.

  18. Applications of Dynamic Clamp to Cardiac Arrhythmia Research: Role in Drug Target Discovery and Safety Pharmacology Testing.

    Science.gov (United States)

    Ortega, Francis A; Grandi, Eleonora; Krogh-Madsen, Trine; Christini, David J

    2017-01-01

    Dynamic clamp, a hybrid-computational-experimental technique that has been used to elucidate ionic mechanisms underlying cardiac electrophysiology, is emerging as a promising tool in the discovery of potential anti-arrhythmic targets and in pharmacological safety testing. Through the injection of computationally simulated conductances into isolated cardiomyocytes in a real-time continuous loop, dynamic clamp has greatly expanded the capabilities of patch clamp outside traditional static voltage and current protocols. Recent applications include fine manipulation of injected artificial conductances to identify promising drug targets in the prevention of arrhythmia and the direct testing of model-based hypotheses. Furthermore, dynamic clamp has been used to enhance existing experimental models by addressing their intrinsic limitations, which increased predictive power in identifying pro-arrhythmic pharmacological compounds. Here, we review the recent advances of the dynamic clamp technique in cardiac electrophysiology with a focus on its future role in the development of safety testing and discovery of anti-arrhythmic drugs.

  19. Loading dynamics of a sliding DNA clamp.

    Science.gov (United States)

    Cho, Won-Ki; Jergic, Slobodan; Kim, Daehyung; Dixon, Nicholas E; Lee, Jong-Bong

    2014-06-23

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

  20. On the mechanism of loading the PCNA sliding clamp by RFC.

    Science.gov (United States)

    Dionne, Isabelle; Brown, Nicola J; Woodgate, Roger; Bell, Stephen D

    2008-04-01

    Sliding clamps play central roles in a broad range of DNA replication and repair processes. The clamps form circular molecules that must be opened and resealed around DNA by the clamp loader complex to fulfil their function. While most eukaryotes and many archea possess a homo-trimeric PCNA, the PCNA of Sulfolobus solfataricus is a heterotrimer. Here, we exploit the asymmetry of S. solfataricus PCNA to create a series of circularly permuted PCNA subunit fusions, thereby covalently closing defined interfaces within the heterotrimer. Using these concatamers, we investigate the requirements for loading the clamp onto DNA and reveal that a single defined interface within the heterotrimer is opened during the loading process. Subunit-specific interactions between S. solfataricus RFC clamp loader and PCNA permit us to superimpose our data upon the structure of yeast RFC-PCNA complex, thereby presenting a general model for PCNA loading by RFC in archaea and eukaryotes.

  1. Behavior of TOC in a Deep Confined Aquifer During Groundwater Artificial Recharge Process

    Science.gov (United States)

    Zhang, W.; He, H.; Shi, X.

    2013-12-01

    In recent years, environmental geological problems such as land subsidence, land collapse, land cracking and salt-water intrusion have become important factors limiting economic development in some cities due to severe overexploitation of groundwater. So, a number of cities have carried out artificial recharge projects, which have played a significant role in controlling these problems. However, with the increasing trend of organic pollution appeared in the surface water, organic contaminated problems should not be neglected during this process. Although the organic components were always following in a lower concentration level, whether it would make groundwater face the organic pollution crisis was unknown for its' higher toxicity and durability. Based on a typical artificial recharge test carried out in a deep confined aquifer in this study area (located in Eastern China, there are 10 monitoring wells and 1 recharge well) that decided to control the field land subsidence, Total Organic Carbon (TOC) was selected as the target components to reveal the organic elements' changing trend during groundwater artificial recharge process. The results (Fig. 1) showed that the concentration of TOC in each monitoring well was appeared in an increasing trend due to the mix influence of the recharge water (TOC was 1.88mg/L) and the origin groundwater (TOC was 0.58mg/L). But the maximum concentrations of TOC in J4, J5, J6 monitoring well (the distance from recharge well was 10m, 17m, 31m respectively) were lower than the recharge water 0.28, 0.49, 0.74 mg/L respectively, with non-linear growth. It indicated that except adsorption, microbial degradation might also occur in the aquifer during artificial recharge. With the groundwater environment from relatively anaerobic environment turn to aerobic environment, DO was able to characterize the relative strength of the TOC biodegradation. The average value of DO in recharge water was 4.33 mg/L, and the maximum value of DO in J4, J5

  2. Process sensors characterization based on noise analysis technique and artificial intelligence

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Roberto N. de; Perillo, Sergio R.P.; Santos, Roberto C. dos [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: rnavarro@ipen.br; sperillo@ipen.br; rcsantos@ipen.br

    2005-07-01

    The time response of pressure and temperature sensors from the Reactor Protection System (RPS) is a requirement that must be satisfied in nuclear power plants, furthermore is an indicative of its degradation and its remaining life. The nuclear power industry and others have been eager to implement smart sensor technologies and digital instrumentation concepts to reduce manpower and effort currently spent on testing and calibration. Process parameters fluctuations during normal operation of a reactor are caused by random variations in neutron flux, heat transfer and other sources. The output sensor noise can be considered as the response of the system to an input representing the statistical nature of the underlying process which can be modeled using a time series model. Since the noise signal measurements are influenced by many factors, such as location of sensors, extraneous noise interference, and randomness in temperature and pressure fluctuation - the quantitative estimate of the time response using autoregressive noise modeling is subject to error. This technique has been used as means of sensor monitoring. In this work a set of pressure sensors installed in one experimental loop adapted from a flow calibration setup is used to test and analyze signals in a new approach using artificial intelligence techniques. A set of measurements of dynamic signals in different experimental conditions is used to distinguish and identify underlying process sources. A methodology that uses Blind Separation of Sources with a neural networks scheme is being developed to improve time response estimate reliability in noise analysis. (author)

  3. Is artificial recharge promoting microbial activity and biodegradation processes in groundwater systems?

    Science.gov (United States)

    Barba Ferrer, Carme; Folch, Albert; Gaju, Núria; Martínez-Alonso, Maira; Carrasquilla, Marc; Grau-Martínez, Alba; Sanchez-Vila, Xavier

    2016-04-01

    Managed Artificial Recharge (MAR) represents a strategic tool for managing water resources, especially during scarce periods. On one hand, it can increase water stored in aquifers and extract it when weather conditions do not permit exclusive exploitation of surface resources. On the other, it allows improve water quality due the processes occurring into the soil whereas water crosses vadose zone. Barcelona (Catalonia, Spain) conurbation is suffering significant quantitative and qualitative groundwater disturbances. For this reason, Sant Vicenç MAR system, constituted by a sedimentation and an infiltration pond, was constructed in 2009 as the strategic water management infrastructure. Compared with other MAR facilities, this infiltration pond has a reactive bed formed by organic compost and local material. The objective is to promote different redox states allowing more and different degradation of chemical compounds than regular MAR systems. In previous studies in the site, physical and hydrochemical parameters demonstrated that there was indeed a degradation of different pollutants. However, to go a step further understanding the different biogeochemical processes and the related degradation processes occurring in the system, we studied the existing microbial communities. So, molecular techniques were applied in water and soil samples in two different scenarios; the first one, when the system was fully operating and the second when the system was not operating during some months. We have specifically compared microbial diversity and richness indexes and both cluster dendrograms obtained from DGGEs analysis made in each sampling campaign.

  4. A study of combined separation process in uranium of artificial sea water

    International Nuclear Information System (INIS)

    Shirotsuka, Tadashi; Inoue, Eiji

    1980-01-01

    For the purpose of recovering uranium from sea water, the study has been made on the adsorption of uranium in artificial sea water with powdered titanic acid. Foam separation process has been proposed which is composed of adsorption with powdered titanic acid and ion flotation. In the experiment of adsorption, the apparent adsorption rate coefficient of combined process proved to be larger than that of continuously stirring system. The relation between uranium adsorbed capacity and concentration of uranium in the solution was arranged by Freundlich's equation. Recovery of uranium from sea water was found to be about 3,000 μg-U/g-Ad in 15 days stirring. Advisable condition of combined separation process is shown as follows: 1. Surface active agent ... DBS, 2. Concentration of DBS ... 1.0 mg/l, 3. Gas velocity ... 0.25 cm/sec. Separation of powdered titanic acid from bulk liquid was recovered 90% by flotation with DBS concentration of 150 mg/l. (author)

  5. Anticipation by multi-modal association through an artificial mental imagery process

    Science.gov (United States)

    Gaona, Wilmer; Escobar, Esaú; Hermosillo, Jorge; Lara, Bruno

    2015-01-01

    Mental imagery has become a central issue in research laboratories seeking to emulate basic cognitive abilities in artificial agents. In this work, we propose a computational model to produce an anticipatory behaviour by means of a multi-modal off-line hebbian association. Unlike the current state of the art, we propose to apply hebbian learning during an internal sensorimotor simulation, emulating a process of mental imagery. We associate visual and tactile stimuli re-enacted by a long-term predictive simulation chain motivated by covert actions. As a result, we obtain a neural network which provides a robot with a mechanism to produce a visually conditioned obstacle avoidance behaviour. We developed our system in a physical Pioneer 3-DX robot and realised two experiments. In the first experiment we test our model on one individual navigating in two different mazes. In the second experiment we assess the robustness of the model by testing in a single environment five individuals trained under different conditions. We believe that our work offers an underpinning mechanism in cognitive robotics for the study of motor control strategies based on internal simulations. These strategies can be seen analogous to the mental imagery process known in humans, opening thus interesting pathways to the construction of upper-level grounded cognitive abilities.

  6. Artificial neural network modeling of mechanical alloying process for synthesizing of metal matrix nanocomposite powders

    International Nuclear Information System (INIS)

    Dashtbayazi, M.R.; Shokuhfar, A.; Simchi, A.

    2007-01-01

    An artificial neural network model was developed for modeling of the effects of mechanical alloying parameters including milling time, milling speed and ball to powder weight ratio on the characteristics of Al-8 vol%SiC nanocomposite powders. The crystallite size and lattice strain of the aluminum matrix were considered for modeling. This nanostructured nanocomposite powder was synthesized by utilizing planetary high energy ball mill and the required data for training were collected from the experimental results. The characteristics of the particles were determined by X-ray diffraction, scanning and transmission electron microscopy. Two types of neural network architecture, i.e. multi-layer perceptron (MLP) and radial basis function (RBF), were used. The steepest descent along with variable learning rate back-propagation algorithm known as a heuristic technique was utilized for training the MLP network. It was found that MLP network yields better results compared to RBF network, giving an acceptable mapping between the network responses and the target data with a high correlation coefficients. The response surfaces between the response variables, i.e. crystallite size, lattice strain of the aluminum matrix and the processing parameters are presented. The procedure modeling can be used for optimization of the MA process for synthesizing of nanostructured metal matrix nanocomposites

  7. Modeling of yield and environmental impact categories in tea processing units based on artificial neural networks.

    Science.gov (United States)

    Khanali, Majid; Mobli, Hossein; Hosseinzadeh-Bandbafha, Homa

    2017-12-01

    In this study, an artificial neural network (ANN) model was developed for predicting the yield and life cycle environmental impacts based on energy inputs required in processing of black tea, green tea, and oolong tea in Guilan province of Iran. A life cycle assessment (LCA) approach was used to investigate the environmental impact categories of processed tea based on the cradle to gate approach, i.e., from production of input materials using raw materials to the gate of tea processing units, i.e., packaged tea. Thus, all the tea processing operations such as withering, rolling, fermentation, drying, and packaging were considered in the analysis. The initial data were obtained from tea processing units while the required data about the background system was extracted from the EcoInvent 2.2 database. LCA results indicated that diesel fuel and corrugated paper box used in drying and packaging operations, respectively, were the main hotspots. Black tea processing unit caused the highest pollution among the three processing units. Three feed-forward back-propagation ANN models based on Levenberg-Marquardt training algorithm with two hidden layers accompanied by sigmoid activation functions and a linear transfer function in output layer, were applied for three types of processed tea. The neural networks were developed based on energy equivalents of eight different input parameters (energy equivalents of fresh tea leaves, human labor, diesel fuel, electricity, adhesive, carton, corrugated paper box, and transportation) and 11 output parameters (yield, global warming, abiotic depletion, acidification, eutrophication, ozone layer depletion, human toxicity, freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, terrestrial ecotoxicity, and photochemical oxidation). The results showed that the developed ANN models with R 2 values in the range of 0.878 to 0.990 had excellent performance in predicting all the output variables based on inputs. Energy consumption for

  8. State of the art of pipe clamp analysis

    International Nuclear Information System (INIS)

    Fang, P.J.

    1984-01-01

    Various types of clamps are used as a component of piping support structures in nuclear power plants. The clamp is referred to as a nonintegral attachment to pipe in contrast to lugs which are integrally welded to the pipe wall. An analysis to determine the load capacity of a clamp is complicated by the fact that the distribution of contact stresses acting on the clamp-pipe interface is a nonlinearly dependent on the geometry of the clamp and pipe, clamping force preapplied to the clamp, and external loads. This paper reviews various methods of clamp analysis including both the closed-formed solutions and the finite element approach. While conventional two- and three-bolt clamps for a horizontal pipe run are emphasized, stiff clamps and riser clamps are also discussed. Finally, the potential effects of interaction between the clamp and pipe are evaluated. (Author) [pt

  9. Fronto-Parietal Contributions to Phonological Processes in Successful Artificial Grammar Learning

    Science.gov (United States)

    Goranskaya, Dariya; Kreitewolf, Jens; Mueller, Jutta L.; Friederici, Angela D.; Hartwigsen, Gesa

    2016-01-01

    Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e., of syllables or letters). In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI), participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison, and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes. PMID:27877120

  10. Fronto-parietal contributions to phonological processes in successful artificial grammar learning

    Directory of Open Access Journals (Sweden)

    Dariya Goranskaya

    2016-11-01

    Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

  11. Feed Forward Artificial Neural Network Model to Estimate the TPH Removal Efficiency in Soil Washing Process

    Directory of Open Access Journals (Sweden)

    Hossein Jafari Mansoorian

    2017-01-01

    Full Text Available Background & Aims of the Study: A feed forward artificial neural network (FFANN was developed to predict the efficiency of total petroleum hydrocarbon (TPH removal from a contaminated soil, using soil washing process with Tween 80. The main objective of this study was to assess the performance of developed FFANN model for the estimation of   TPH removal. Materials and Methods: Several independent repressors including pH, shaking speed, surfactant concentration and contact time were used to describe the removal of TPH as a dependent variable in a FFANN model. 85% of data set observations were used for training the model and remaining 15% were used for model testing, approximately. The performance of the model was compared with linear regression and assessed, using Root of Mean Square Error (RMSE as goodness-of-fit measure Results: For the prediction of TPH removal efficiency, a FANN model with a three-hidden-layer structure of 4-3-1 and a learning rate of 0.01 showed the best predictive results. The RMSE and R2 for the training and testing steps of the model were obtained to be 2.596, 0.966, 10.70 and 0.78, respectively. Conclusion: For about 80% of the TPH removal efficiency can be described by the assessed regressors the developed model. Thus, focusing on the optimization of soil washing process regarding to shaking speed, contact time, surfactant concentration and pH can improve the TPH removal performance from polluted soils. The results of this study could be the basis for the application of FANN for the assessment of soil washing process and the control of petroleum hydrocarbon emission into the environments.

  12. Expanding the occupational health methodology: A concatenated artificial neural network approach to model the burnout process in Chinese nurses.

    Science.gov (United States)

    Ladstätter, Felix; Garrosa, Eva; Moreno-Jiménez, Bernardo; Ponsoda, Vicente; Reales Aviles, José Manuel; Dai, Junming

    2016-01-01

    Artificial neural networks are sophisticated modelling and prediction tools capable of extracting complex, non-linear relationships between predictor (input) and predicted (output) variables. This study explores this capacity by modelling non-linearities in the hardiness-modulated burnout process with a neural network. Specifically, two multi-layer feed-forward artificial neural networks are concatenated in an attempt to model the composite non-linear burnout process. Sensitivity analysis, a Monte Carlo-based global simulation technique, is then utilised to examine the first-order effects of the predictor variables on the burnout sub-dimensions and consequences. Results show that (1) this concatenated artificial neural network approach is feasible to model the burnout process, (2) sensitivity analysis is a prolific method to study the relative importance of predictor variables and (3) the relationships among variables involved in the development of burnout and its consequences are to different degrees non-linear. Many relationships among variables (e.g., stressors and strains) are not linear, yet researchers use linear methods such as Pearson correlation or linear regression to analyse these relationships. Artificial neural network analysis is an innovative method to analyse non-linear relationships and in combination with sensitivity analysis superior to linear methods.

  13. Application of life cycle assessment to production processes of environmentally sustainable concrete, prepared with artificial aggregates

    International Nuclear Information System (INIS)

    Vaccaro, R.; Colangelo, F.; Palumbo, M.; Cioffi, R.

    2005-01-01

    This paper is about the application of Life Cycle Assessment (L.C.A.) on environmentally sustainable concrete production processes. The goal of this experimentations is to assess environmental impact and energy demand related to concrete production, by using, in different admixtures, natural and artificial aggregates, belonging from treatments of different kind of industrial wastes characterized by very small particle sizes. Particular attention was concentrated on the utilization of fine fraction since it is difficult to recover in usual fields of recycling (i.e. aggers, crowl spaces, etc.). This study follows the approach from cradle to cradle. This experimentation was conducted in relation to four concrete admixtures produced, one of them containing only natural aggregate, and the other ones obtained by substituting the 10% of aggregate respectively with inert wastes as construction and demolition waste (CeD waste). cement kiln dust (CKD) and marble sludge. For all admixtures six different end-life scenarios have been proposed, one of them considers all materials transported in landfill while the other ones consider a partial transportation on landfill (15%) and a recycle of the 85% of wastes obtained after demolition of structures [it

  14. Digital image analysis in breast pathology-from image processing techniques to artificial intelligence.

    Science.gov (United States)

    Robertson, Stephanie; Azizpour, Hossein; Smith, Kevin; Hartman, Johan

    2018-04-01

    Breast cancer is the most common malignant disease in women worldwide. In recent decades, earlier diagnosis and better adjuvant therapy have substantially improved patient outcome. Diagnosis by histopathology has proven to be instrumental to guide breast cancer treatment, but new challenges have emerged as our increasing understanding of cancer over the years has revealed its complex nature. As patient demand for personalized breast cancer therapy grows, we face an urgent need for more precise biomarker assessment and more accurate histopathologic breast cancer diagnosis to make better therapy decisions. The digitization of pathology data has opened the door to faster, more reproducible, and more precise diagnoses through computerized image analysis. Software to assist diagnostic breast pathology through image processing techniques have been around for years. But recent breakthroughs in artificial intelligence (AI) promise to fundamentally change the way we detect and treat breast cancer in the near future. Machine learning, a subfield of AI that applies statistical methods to learn from data, has seen an explosion of interest in recent years because of its ability to recognize patterns in data with less need for human instruction. One technique in particular, known as deep learning, has produced groundbreaking results in many important problems including image classification and speech recognition. In this review, we will cover the use of AI and deep learning in diagnostic breast pathology, and other recent developments in digital image analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Artificial patina formation onto copper-based alloys: Chloride and sulphate induced corrosion processes

    Science.gov (United States)

    Di Carlo, G.; Giuliani, C.; Riccucci, C.; Pascucci, M.; Messina, E.; Fierro, G.; Lavorgna, M.; Ingo, G. M.

    2017-11-01

    Naturally grown patinas are typically detected onto the surface of modern copper-based artefacts and strictly affect their surface reactivity and appearance. The production of representative patinas is a key issues in order to obtain model systems which can be used for the development and validation of appropriate conservation materials and methods. In this study, we have prepared different artificial representative patinas by using a quaternary Cu-Sn-Zn-Pb alloy with chemical composition and metallurgical features similar to those of valuable modern works of art. In order to produce degradation products usually observed onto their surface, chloride and sulphate species were used to induce corrosion processes. Different patinas were produced by changing the nature of corrosive species and the set-up for the accelerated degradation. The composition and structural properties of the patinas were investigated by attenuated total reflectance Fourier transform infrared spectroscopy, X-ray diffraction, optical microscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy. The results allow to identify degradation products and to distinguish copper hydroxychloride polymorphs and copper hydroxysulphates with similar structure. Our findings show that patina composition can be tailored by modifying the degradation procedure and patinas representative of modern artefacts made of quaternary Cu-Sn-Zn-Pb alloy can be obtained.

  16. Experimental study and artificial neural network modeling of tartrazine removal by photocatalytic process under solar light.

    Science.gov (United States)

    Sebti, Aicha; Souahi, Fatiha; Mohellebi, Faroudja; Igoud, Sadek

    2017-07-01

    This research focuses on the application of an artificial neural network (ANN) to predict the removal efficiency of tartrazine from simulated wastewater using a photocatalytic process under solar illumination. A program is developed in Matlab software to optimize the neural network architecture and select the suitable combination of training algorithm, activation function and hidden neurons number. The experimental results of a batch reactor operated under different conditions of pH, TiO 2 concentration, initial organic pollutant concentration and solar radiation intensity are used to train, validate and test the networks. While negligible mineralization is demonstrated, the experimental results show that under sunlight irradiation, 85% of tartrazine is removed after 300 min using only 0.3 g/L of TiO 2 powder. Therefore, irradiation time is prolonged and almost 66% of total organic carbon is reduced after 15 hours. ANN 5-8-1 with Bayesian regulation back-propagation algorithm and hyperbolic tangent sigmoid transfer function is found to be able to predict the response with high accuracy. In addition, the connection weights approach is used to assess the importance contribution of each input variable on the ANN model response. Among the five experimental parameters, the irradiation time has the greatest effect on the removal efficiency of tartrazine.

  17. Artificial intelligence framework for simulating clinical decision-making: a Markov decision process approach.

    Science.gov (United States)

    Bennett, Casey C; Hauser, Kris

    2013-01-01

    In the modern healthcare system, rapidly expanding costs/complexity, the growing myriad of treatment options, and exploding information streams that often do not effectively reach the front lines hinder the ability to choose optimal treatment decisions over time. The goal in this paper is to develop a general purpose (non-disease-specific) computational/artificial intelligence (AI) framework to address these challenges. This framework serves two potential functions: (1) a simulation environment for exploring various healthcare policies, payment methodologies, etc., and (2) the basis for clinical artificial intelligence - an AI that can "think like a doctor". This approach combines Markov decision processes and dynamic decision networks to learn from clinical data and develop complex plans via simulation of alternative sequential decision paths while capturing the sometimes conflicting, sometimes synergistic interactions of various components in the healthcare system. It can operate in partially observable environments (in the case of missing observations or data) by maintaining belief states about patient health status and functions as an online agent that plans and re-plans as actions are performed and new observations are obtained. This framework was evaluated using real patient data from an electronic health record. The results demonstrate the feasibility of this approach; such an AI framework easily outperforms the current treatment-as-usual (TAU) case-rate/fee-for-service models of healthcare. The cost per unit of outcome change (CPUC) was $189 vs. $497 for AI vs. TAU (where lower is considered optimal) - while at the same time the AI approach could obtain a 30-35% increase in patient outcomes. Tweaking certain AI model parameters could further enhance this advantage, obtaining approximately 50% more improvement (outcome change) for roughly half the costs. Given careful design and problem formulation, an AI simulation framework can approximate optimal

  18. Automated identification of copepods using digital image processing and artificial neural network.

    Science.gov (United States)

    Leow, Lee Kien; Chew, Li-Lee; Chong, Ving Ching; Dhillon, Sarinder Kaur

    2015-01-01

    Copepods are planktonic organisms that play a major role in the marine food chain. Studying the community structure and abundance of copepods in relation to the environment is essential to evaluate their contribution to mangrove trophodynamics and coastal fisheries. The routine identification of copepods can be very technical, requiring taxonomic expertise, experience and much effort which can be very time-consuming. Hence, there is an urgent need to introduce novel methods and approaches to automate identification and classification of copepod specimens. This study aims to apply digital image processing and machine learning methods to build an automated identification and classification technique. We developed an automated technique to extract morphological features of copepods' specimen from captured images using digital image processing techniques. An Artificial Neural Network (ANN) was used to classify the copepod specimens from species Acartia spinicauda, Bestiolina similis, Oithona aruensis, Oithona dissimilis, Oithona simplex, Parvocalanus crassirostris, Tortanus barbatus and Tortanus forcipatus based on the extracted features. 60% of the dataset was used for a two-layer feed-forward network training and the remaining 40% was used as testing dataset for system evaluation. Our approach demonstrated an overall classification accuracy of 93.13% (100% for A. spinicauda, B. similis and O. aruensis, 95% for T. barbatus, 90% for O. dissimilis and P. crassirostris, 85% for O. similis and T. forcipatus). The methods presented in this study enable fast classification of copepods to the species level. Future studies should include more classes in the model, improving the selection of features, and reducing the time to capture the copepod images.

  19. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    Science.gov (United States)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  20. Core clamping device for a nuclear reactor

    International Nuclear Information System (INIS)

    Guenther, R.W.

    1974-01-01

    The core clamping device for a fast neutron reactor includes clamps to support the fuel zone against the pressure vessel. The clamps are arranged around the circumference of the core. They consist of torsion bars arranged parallel at some distance around the core with lever arms attached to the ends whose force is directed in the opposite direction, pressing against the wall of the pressure vessel. The lever arms and pressure plates also actuated by the ends of the torsion bars transfer the stress, the pressure plates acting upon the fuel elements or fuel assemblies. Coupling between the ends of the torsion bars and the pressure plates is achieved by end carrier plates directly attached to the torsion bars and radially movable. This clamping device follows the thermal expansions of the core, allows specific elements to be disengaged in sections and saves space between the core and the neutron reflectors. (DG) [de

  1. Formal Design Review Foot Clamp Modification

    International Nuclear Information System (INIS)

    OTEN, T.C.

    2000-01-01

    This report documents the Design Review performed for the foot clamp modification. The report documents the acceptability of the design, identifies the documents that were reviewed, the scope of the review and the members of the review team

  2. Clamp force and alignment checking device

    Science.gov (United States)

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  3. Patch-Clamp Recording from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Improving Action Potential Characteristics through Dynamic Clamp

    Science.gov (United States)

    Veerman, Christiaan C.; Zegers, Jan G.; Mengarelli, Isabella; Bezzina, Connie R.

    2017-01-01

    Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great promise for studying inherited cardiac arrhythmias and developing drug therapies to treat such arrhythmias. Unfortunately, until now, action potential (AP) measurements in hiPSC-CMs have been hampered by the virtual absence of the inward rectifier potassium current (IK1) in hiPSC-CMs, resulting in spontaneous activity and altered function of various depolarising and repolarising membrane currents. We assessed whether AP measurements in “ventricular-like” and “atrial-like” hiPSC-CMs could be improved through a simple, highly reproducible dynamic clamp approach to provide these cells with a substantial IK1 (computed in real time according to the actual membrane potential and injected through the patch-clamp pipette). APs were measured at 1 Hz using perforated patch-clamp methodology, both in control cells and in cells treated with all-trans retinoic acid (RA) during the differentiation process to increase the number of cells with atrial-like APs. RA-treated hiPSC-CMs displayed shorter APs than control hiPSC-CMs and this phenotype became more prominent upon addition of synthetic IK1 through dynamic clamp. Furthermore, the variability of several AP parameters decreased upon IK1 injection. Computer simulations with models of ventricular-like and atrial-like hiPSC-CMs demonstrated the importance of selecting an appropriate synthetic IK1. In conclusion, the dynamic clamp-based approach of IK1 injection has broad applicability for detailed AP measurements in hiPSC-CMs. PMID:28867785

  4. Patch-Clamp Recording from Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes: Improving Action Potential Characteristics through Dynamic Clamp.

    Science.gov (United States)

    Verkerk, Arie O; Veerman, Christiaan C; Zegers, Jan G; Mengarelli, Isabella; Bezzina, Connie R; Wilders, Ronald

    2017-08-30

    Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) hold great promise for studying inherited cardiac arrhythmias and developing drug therapies to treat such arrhythmias. Unfortunately, until now, action potential (AP) measurements in hiPSC-CMs have been hampered by the virtual absence of the inward rectifier potassium current ( I K1 ) in hiPSC-CMs, resulting in spontaneous activity and altered function of various depolarising and repolarising membrane currents. We assessed whether AP measurements in "ventricular-like" and "atrial-like" hiPSC-CMs could be improved through a simple, highly reproducible dynamic clamp approach to provide these cells with a substantial I K1 (computed in real time according to the actual membrane potential and injected through the patch-clamp pipette). APs were measured at 1 Hz using perforated patch-clamp methodology, both in control cells and in cells treated with all-trans retinoic acid (RA) during the differentiation process to increase the number of cells with atrial-like APs. RA-treated hiPSC-CMs displayed shorter APs than control hiPSC-CMs and this phenotype became more prominent upon addition of synthetic I K1 through dynamic clamp. Furthermore, the variability of several AP parameters decreased upon I K1 injection. Computer simulations with models of ventricular-like and atrial-like hiPSC-CMs demonstrated the importance of selecting an appropriate synthetic I K1 . In conclusion, the dynamic clamp-based approach of I K1 injection has broad applicability for detailed AP measurements in hiPSC-CMs.

  5. Sound absorption by clamped poroelastic plates.

    Science.gov (United States)

    Aygun, H; Attenborough, K

    2008-09-01

    Measurements and predictions have been made of the absorption coefficient and the surface acoustic impedance of poroelastic plates clamped in a large impedance tube and separated from the rigid termination by an air gap. The measured and predicted absorption coefficient and surface impedance spectra exhibit low frequency peaks. The peak frequencies observed in the absorption coefficient are close to those predicted and measured in the deflection spectra of the clamped poroelastic plates. The influences of the rigidity of the clamping conditions and the width of the air gap have been investigated. Both influences are found to be important. Increasing the rigidity of clamping reduces the low frequency absorption peaks compared with those measured for simply supported plates or plates in an intermediate clamping condition. Results for a closed cell foam plate and for two open cell foam plates made from recycled materials are presented. For identical clamping conditions and width of air gap, the results for the different materials differ as a consequence mainly of their different elasticity, thickness, and cell structure.

  6. Optimisation of sonourethrography: the clamp method.

    Science.gov (United States)

    Berná-Mestre, Juan de Dios; Balmaceda, Thierry; Martínez, Diego; Escudero, Jose F; Martínez, Gloria; García, José A; Canteras, Manuel; Berná-Serna, Juan D

    2018-05-01

    To describe the clamp method for performing retrograde sonourethrography (RSUG) and contrast-enhanced voiding sonourethrography (CE-VSUG) via the transperineal approach in male adults. Prospective study of 113 males (14-86 years) with urethral strictures confirmed by urethrography who received sonourethrography via the clamp method between 2011 and 2015. The characteristic parameters of the quantitative variables were calculated and a comparative analysis of the qualitative variables was conducted using the McNemar test. RSUG was performed successfully in all the cases (n = 113) and detected 49 cases with anterior urethral strictures; the strictures in the proximal bulbar cone in five of them (10.2%) were not visualised on retrograde urethrography (RUG) (p clamp method enables RSUG and CE-VSUG to be performed simply, effectively and painlessly by a single operator. It also allows the evaluation of cases with urethromeatal alterations (stricture, hypospadias and meatotomy). • The clamp method enables RSUG to be performed simply and painlessly. • The clamp method requires only one operator and allows assessing urethromeatal alterations. • RSUG shows greater capacity for detecting anterior urethral strictures than RUG. • The clamp method achieves retrograde bladder filling in approximately 6 min. • CE-VSUG shows greater capacity for detecting strictures than VCUG.

  7. NMR resonance assignments for the N-terminal domain of the δ subunit of the E. coli γ clamp loader complex.

    Science.gov (United States)

    Alyami, Esmael M; Rizzo, Alessandro A; Beuning, Penny J; Korzhnev, Dmitry M

    2017-10-01

    The β-clamp protein and the γ clamp loader complex are essential components of bacterial DNA replication machinery. The β-clamp is a ring-shaped homodimer that encircles DNA and increases the efficiency of replication by providing a binding platform for DNA polymerases and other replication-related proteins. The β-clamp is loaded onto DNA by the five-subunit γ clamp loader complex in a multi-step ATP-dependent process. The initial steps of this process involve the cooperative binding of the β-clamp by the five subunits of ATP-bound clamp loader, which induces or traps an open conformation of the clamp. Remarkably, the δ subunit of the E. coli clamp loader, or even its 140 residue N-terminal domain (called mini-δ), alone can shift conformational equilibrium of the β-clamp towards the open state. Here we report nearly complete backbone and side-chain 1 H, 13 C and 15 N NMR resonance assignments of mini-δ that will facilitate NMR studies of the mechanisms of β-clamp opening and its loading on DNA by the clamp loader.

  8. Computer aided diagnosis based on medical image processing and artificial intelligence methods

    International Nuclear Information System (INIS)

    Stoitsis, John; Valavanis, Ioannis; Mougiakakou, Stavroula G.; Golemati, Spyretta; Nikita, Alexandra; Nikita, Konstantina S.

    2006-01-01

    Advances in imaging technology and computer science have greatly enhanced interpretation of medical images, and contributed to early diagnosis. The typical architecture of a Computer Aided Diagnosis (CAD) system includes image pre-processing, definition of region(s) of interest, features extraction and selection, and classification. In this paper, the principles of CAD systems design and development are demonstrated by means of two examples. The first one focuses on the differentiation between symptomatic and asymptomatic carotid atheromatous plaques. For each plaque, a vector of texture and motion features was estimated, which was then reduced to the most robust ones by means of ANalysis of VAriance (ANOVA). Using fuzzy c-means, the features were then clustered into two classes. Clustering performances of 74%, 79%, and 84% were achieved for texture only, motion only, and combinations of texture and motion features, respectively. The second CAD system presented in this paper supports the diagnosis of focal liver lesions and is able to characterize liver tissue from Computed Tomography (CT) images as normal, hepatic cyst, hemangioma, and hepatocellular carcinoma. Five texture feature sets were extracted for each lesion, while a genetic algorithm based feature selection method was applied to identify the most robust features. The selected feature set was fed into an ensemble of neural network classifiers. The achieved classification performance was 100%, 93.75% and 90.63% in the training, validation and testing set, respectively. It is concluded that computerized analysis of medical images in combination with artificial intelligence can be used in clinical practice and may contribute to more efficient diagnosis

  9. Computer aided diagnosis based on medical image processing and artificial intelligence methods

    Energy Technology Data Exchange (ETDEWEB)

    Stoitsis, John [National Technical University of Athens, School of Electrical and Computer Engineering, Athens 157 71 (Greece)]. E-mail: stoitsis@biosim.ntua.gr; Valavanis, Ioannis [National Technical University of Athens, School of Electrical and Computer Engineering, Athens 157 71 (Greece); Mougiakakou, Stavroula G. [National Technical University of Athens, School of Electrical and Computer Engineering, Athens 157 71 (Greece); Golemati, Spyretta [National Technical University of Athens, School of Electrical and Computer Engineering, Athens 157 71 (Greece); Nikita, Alexandra [University of Athens, Medical School 152 28 Athens (Greece); Nikita, Konstantina S. [National Technical University of Athens, School of Electrical and Computer Engineering, Athens 157 71 (Greece)

    2006-12-20

    Advances in imaging technology and computer science have greatly enhanced interpretation of medical images, and contributed to early diagnosis. The typical architecture of a Computer Aided Diagnosis (CAD) system includes image pre-processing, definition of region(s) of interest, features extraction and selection, and classification. In this paper, the principles of CAD systems design and development are demonstrated by means of two examples. The first one focuses on the differentiation between symptomatic and asymptomatic carotid atheromatous plaques. For each plaque, a vector of texture and motion features was estimated, which was then reduced to the most robust ones by means of ANalysis of VAriance (ANOVA). Using fuzzy c-means, the features were then clustered into two classes. Clustering performances of 74%, 79%, and 84% were achieved for texture only, motion only, and combinations of texture and motion features, respectively. The second CAD system presented in this paper supports the diagnosis of focal liver lesions and is able to characterize liver tissue from Computed Tomography (CT) images as normal, hepatic cyst, hemangioma, and hepatocellular carcinoma. Five texture feature sets were extracted for each lesion, while a genetic algorithm based feature selection method was applied to identify the most robust features. The selected feature set was fed into an ensemble of neural network classifiers. The achieved classification performance was 100%, 93.75% and 90.63% in the training, validation and testing set, respectively. It is concluded that computerized analysis of medical images in combination with artificial intelligence can be used in clinical practice and may contribute to more efficient diagnosis.

  10. Use of the Satinsky clamp for hilar clamping during robotic partial nephrectomy: indications, technique, and multi-center outcomes.

    Science.gov (United States)

    Abdullah, Newaj; Rahbar, Haider; Barod, Ravi; Dalela, Deepansh; Larson, Jeff; Johnson, Michael; Mass, Alon; Zargar, Homayoun; Kaouk, Jihad; Allaf, Mohamad; Bhayani, Sam; Stifelman, Michael; Rogers, Craig

    2017-03-01

    A Satinsky clamp may be a backup option for hilar clamping during robotic partial nephrectomy (RPN) if there are challenges with application of bulldog clamps, but there are potential safety concerns. We evaluate outcomes of RPN using Satinsky vs. bulldog clamps, and provide tips for safe use of the Satinsky as a backup option. Using a multi-center database, we identified 1073 patients who underwent RPN between 2006 and 2013, and had information available about method of hilar clamping (bulldog clamp vs. Satinsky clamp). Patient baseline characteristics, tumor features, and perioperative outcomes were compared between the Satinsky and bulldog clamp groups. A Satinsky clamp was used for hilar clamping in 94 (8.8 %) RPN cases, and bulldog clamps were used in 979 (91.2 %) cases. The use of a Satinsky clamp was associated with greater operative time (198 vs. 175 min, p clamp group, but none were directly related to the Satinsky clamp. On multivariable analysis, the use of the Satinsky clamp was not associated with increase in intraoperative or Clavien ≥3 postoperative complications, positive surgical margin rate or percentage change in estimated glomerular filtration rate. A Satinsky clamp can be a backup option for hilar clamping during challenging RPN cases, but requires careful technique, and was rarely necessary.

  11. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used to clamp the patient's skull to hold head and neck in a particular position during surgical procedures. (b...

  12. Conserved residues in the delta subunit help the E. coli clamp loader, gamma complex, target primer-template DNA for clamp assembly.

    Science.gov (United States)

    Chen, Siying; Coman, Maria Magdalena; Sakato, Miho; O'Donnell, Michael; Hingorani, Manju M

    2008-06-01

    The Escherichia coli clamp loader, gamma complex (gamma(3)deltadelta'lambdapsi), catalyzes ATP-driven assembly of beta clamps onto primer-template DNA (p/tDNA), enabling processive replication. The mechanism by which gamma complex targets p/tDNA for clamp assembly is not resolved. According to previous studies, charged/polar amino acids inside the clamp loader chamber interact with the double-stranded (ds) portion of p/tDNA. We find that dsDNA, not ssDNA, can trigger a burst of ATP hydrolysis by gamma complex and clamp assembly, but only at far higher concentrations than p/tDNA. Thus, contact between gamma complex and dsDNA is necessary and sufficient, but not optimal, for the reaction, and additional contacts with p/tDNA likely facilitate its selection as the optimal substrate for clamp assembly. We investigated whether a conserved sequence-HRVW(279)QNRR--in delta subunit contributes to such interactions, since Tryptophan-279 specifically cross-links to the primer-template junction. Mutation of delta-W279 weakens gamma complex binding to p/tDNA, hampering its ability to load clamps and promote proccessive DNA replication, and additional mutations in the sequence (delta-R277, delta-R283) worsen the interaction. These data reveal a novel location in the C-terminal domain of the E. coli clamp loader that contributes to DNA binding and helps define p/tDNA as the preferred substrate for the reaction.

  13. A missing factor in chip-based patch clamp assay: gigaseal

    International Nuclear Information System (INIS)

    Ong, W-L; Yobas, L; Ong, W-Y

    2006-01-01

    The 'gold' standard in the study of ionic currents across biological membranes is the Patch Clamp method. However, this is a slow, labor and skill intensive process. High throughput patch clamp devices are mainly chip-based. A major challenge in these miniaturized devices is the low rate of 'Gigaseal' formation which is critical in the study of Single Channel effect. In a conventional patch clamp, a pipette moves and patches a fixed cell (cell-adhered patch) which is grown on the bottom of a Petri dish. In the chip-based case, the cells are in suspension and move towards the fixed patch clamp sites (cell-suspended patch). In this study, using the proven conventional patch clamp setup, we investigated the effect of the differences in the cell configurations between the convention patch clamp and cell-based patch clamp. It is shown that adhered cells (as used in the conventional setup) have a much higher rate of gigaseal formation as compared to the cells in suspension (as used in chip-based devices). We postulate that the arrangement of the cytoskeleton within the cell plays a major part in the formation of the gigaseal

  14. A study on the advanced methods for on-line signal processing by using artificial intelligence in nuclear power plants

    International Nuclear Information System (INIS)

    Kim, Wan Joo

    1993-02-01

    In order to assist the operators at the transient states of a nuclear power plant, the automation of signal processing is needed. This study has the objective to process the signals from a nuclear power plant for the purpose of advising the operator. To meet this objective, in this study, two kinds of on-line signal processing system based on AI techniques are developed for the nuclear power plant application with on-line signals. First, an artificial neural network for signal prediction is developed for the adequate countermoves at transient states. The steam generator water level is adopted as the example and the outputs of a simulation program for the dynamics of steam generator combined with noises are used as the training patterns. For the training of the artificial neural network, the modified backpropagation algorithm is proposed for escaping quickly from local minima. The modified algorithm is different from the ordinary backpropagation algorithm in the aspect that the training rate coefficient is repeatedly adjusted randomly and taken when the training is improved. This trial has an effect to search for an adequate magnitude of a training rate coefficient. The comparison result shows that the modified algorithm enables the neural network to be trained more quickly. The simulation result shows that the outputs of the artificial neural network are not sensitive to noises. Using the artificial neural networks proposed in this thesis, the operators can predict the next status of a plant and can take actions to maintain the stability of plant. Second, the multi sensor integration system has been developed for the identification of transient states. The developed system is divided into two parts; pre-processors and a fusion part. An artificial neural network is adopted in the fusion part to include the knowledge about the identification and to make a decision of the transient state. The developed pre-processors play a role of classifying the trend types of

  15. The Role of Simple Semantics in the Process of Artificial Grammar Learning

    Science.gov (United States)

    Öttl, Birgit; Jäger, Gerhard; Kaup, Barbara

    2017-01-01

    This study investigated the effect of semantic information on artificial grammar learning (AGL). Recursive grammars of different complexity levels (regular language, mirror language, copy language) were investigated in a series of AGL experiments. In the with-semantics condition, participants acquired semantic information prior to the AGL…

  16. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H.R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Jacobus Adrianus Maria; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    Background To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Methods Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inlay

  17. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H. R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    BACKGROUND: To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. METHODS: Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the

  18. Piezoresistive cantilever force-clamp system

    International Nuclear Information System (INIS)

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L.; Goodman, Miriam B.

    2011-01-01

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of μN force and nm up to tens of μm displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  19. Artificial Intelligence Based Selection of Optimal Cutting Tool and Process Parameters for Effective Turning and Milling Operations

    Science.gov (United States)

    Saranya, Kunaparaju; John Rozario Jegaraj, J.; Ramesh Kumar, Katta; Venkateshwara Rao, Ghanta

    2016-06-01

    With the increased trend in automation of modern manufacturing industry, the human intervention in routine, repetitive and data specific activities of manufacturing is greatly reduced. In this paper, an attempt has been made to reduce the human intervention in selection of optimal cutting tool and process parameters for metal cutting applications, using Artificial Intelligence techniques. Generally, the selection of appropriate cutting tool and parameters in metal cutting is carried out by experienced technician/cutting tool expert based on his knowledge base or extensive search from huge cutting tool database. The present proposed approach replaces the existing practice of physical search for tools from the databooks/tool catalogues with intelligent knowledge-based selection system. This system employs artificial intelligence based techniques such as artificial neural networks, fuzzy logic and genetic algorithm for decision making and optimization. This intelligence based optimal tool selection strategy is developed using Mathworks Matlab Version 7.11.0 and implemented. The cutting tool database was obtained from the tool catalogues of different tool manufacturers. This paper discusses in detail, the methodology and strategies employed for selection of appropriate cutting tool and optimization of process parameters based on multi-objective optimization criteria considering material removal rate, tool life and tool cost.

  20. Artificial Intelligence.

    Science.gov (United States)

    Wash, Darrel Patrick

    1989-01-01

    Making a machine seem intelligent is not easy. As a consequence, demand has been rising for computer professionals skilled in artificial intelligence and is likely to continue to go up. These workers develop expert systems and solve the mysteries of machine vision, natural language processing, and neural networks. (Editor)

  1. Recognition of unnatural variation patterns in metal-stamping process using artificial neural network and statistical features

    Science.gov (United States)

    Rahman, Norasulaini Abdul; Masood, Ibrahim; Nasrull Abdol Rahman, Mohd

    2016-11-01

    Unnatural process variation (UPV) is vital in quality problem of a metalstamping process. It is a major contributor to a poor quality product. The sources of UPV usually found from special causes. Recently, there is still debated among researchers in finding an effective technique for on-line monitoring-diagnosis the sources of UPV. Control charts pattern recognition (CCPR) is the most investigated technique. The existing CCPR schemes were mainly developed using raw data-based artificial neural network (ANN) recognizer, whereby the process samples were mainly generated artificially using mathematical equations. This is because the real process samples were commonly confidential or not economically available. In this research, the statistical features - ANN recognizer was utilized as the control chart pattern recognizer, whereby process sample was taken directly from an actual manufacturing process. Based on dynamic data training, the proposed recognizer has resulted in better monitoring-diagnosis performance (Normal = 100%, Unnatural = 100%) compared to the raw data- ANN (Normal = 66.67%, Unnatural = 26.97%).

  2. Use of artificial neuronal networks for prediction of the control parameters in the process of anaerobic digestion with thermal pretreatment.

    Science.gov (United States)

    Flores-Asis, Rita; Méndez-Contreras, Juan M; Juárez-Martínez, Ulises; Alvarado-Lassman, Alejandro; Villanueva-Vásquez, Daniel; Aguilar-Lasserre, Alberto A

    2018-04-19

    This article focuses on the analysis of the behavior patterns of the variables involved in the anaerobic digestion process. The objective is to predict the impact factor and the behavior pattern of the variables, i.e., temperature, pH, volatile solids (VS), total solids, volumetric load, and hydraulic residence time, considering that these are the control variables for the conservation of the different groups of anaerobic microorganisms. To conduct the research, samples of physicochemical sludge were taken from a water treatment plant in a poultry processing factory, and, then, the substrate was characterized, and a thermal pretreatment was used to accelerate the hydrolysis process. The anaerobic digestion process was analyzed in order to obtain experimental data of the control variables and observe their impact on the production of biogas. The results showed that the thermal pre-hydrolysis applied at 90°C for 90 min accelerated the hydrolysis phase, allowing a significant 52% increase in the volume of methane produced. An artificial neural network was developed, and it was trained with the database obtained by monitoring the anaerobic digestion process. The results obtained from the artificial neural network showed that there is an adjustment between the real values and the prediction of validation based on 60 samples with a 96.4% coefficient of determination, and it was observed that the variables with the major impact on the process were the loading rate and VS, with impact factors of 36% and 23%, respectively.

  3. Altered olfactory processing of stress-related body odors and artificial odors in patients with panic disorder.

    Directory of Open Access Journals (Sweden)

    Gloria-Beatrice Wintermann

    Full Text Available Patients with Panic Disorder (PD direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD.A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry as well as artificial odors (peach, artificial sweat as non-fearful non-body odors.The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology.The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the

  4. IMPORTANT: Fluke is recalling Digital Clamp Meters

    CERN Multimedia

    2013-01-01

    Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

  5. Analysis of the role of PCNA-DNA contacts during clamp loading

    Directory of Open Access Journals (Sweden)

    Goedken Eric R

    2010-01-01

    Full Text Available Abstract Background Sliding clamps, such as Proliferating Cell Nuclear Antigen (PCNA in eukaryotes, are ring-shaped protein complexes that encircle DNA and enable highly processive DNA replication by serving as docking sites for DNA polymerases. In an ATP-dependent reaction, clamp loader complexes, such as the Replication Factor-C (RFC complex in eukaryotes, open the clamp and load it around primer-template DNA. Results We built a model of RFC bound to PCNA and DNA based on existing crystal structures of clamp loaders. This model suggests that DNA would enter the clamp at an angle during clamp loading, thereby interacting with positively charged residues in the center of PCNA. We show that simultaneous mutation of Lys 20, Lys 77, Arg 80, and Arg 149, which interact with DNA in the RFC-PCNA-DNA model, compromises the ability of yeast PCNA to stimulate the DNA-dependent ATPase activity of RFC when the DNA is long enough to extend through the clamp. Fluorescence anisotropy binding experiments show that the inability of the mutant clamp proteins to stimulate RFC ATPase activity is likely caused by reduction in the affinity of the RFC-PCNA complex for DNA. We obtained several crystal forms of yeast PCNA-DNA complexes, measuring X-ray diffraction data to 3.0 Å resolution for one such complex. The resulting electron density maps show that DNA is bound in a tilted orientation relative to PCNA, but makes different contacts than those implicated in clamp loading. Because of apparent partial disorder in the DNA, we restricted refinement of the DNA to a rigid body model. This result contrasts with previous analysis of a bacterial clamp bound to DNA, where the DNA was well resolved. Conclusion Mutational analysis of PCNA suggests that positively charged residues in the center of the clamp create a binding surface that makes contact with DNA. Disruption of this positive surface, which had not previously been implicated in clamp loading function, reduces RFC

  6. Role of nitrification in the biodegradation of selected artificial sweetening agents in biological wastewater treatment process.

    Science.gov (United States)

    Tran, N H; Nguyen, V T; Urase, T; Ngo, H H

    2014-06-01

    The biodegradation of the six artificial sweetening agents including acesulfame (ACE), aspartame (ASP), cyclamate (CYC), neohesperidindihydrochalcone (NHDC), saccharin (SAC), and sucralose (SUC) by nitrifying activated sludge was first examined. Experimental results showed that ASP and NHDC were the most easily degradable compounds even in the control tests. CYC and SAC were efficiently biodegraded by the nitrifying activated sludge, whereas ACE and SUC were poorly removed. However, the biodegradation efficiencies of the ASs were increased with the increase in initial ammonium concentrations in the bioreactors. The association between nitrification and co-metabolic degradation was investigated and a linear relationship between nitrification rate and co-metabolic biodegradation rate was observed for the target artificial sweeteners (ASs). The contribution of heterotrophic microorganisms and autotrophic ammonia oxidizers in biodegradation of the ASs was elucidated, of which autotrophic ammonia oxidizers played an important role in the biodegradation of the ASs, particularly with regards to ACE and SUC. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Artificial Intelligence Framework for Simulating Clinical Decision-Making: A Markov Decision Process Approach

    OpenAIRE

    Bennett, Casey C.; Hauser, Kris

    2013-01-01

    In the modern healthcare system, rapidly expanding costs/complexity, the growing myriad of treatment options, and exploding information streams that often do not effectively reach the front lines hinder the ability to choose optimal treatment decisions over time. The goal in this paper is to develop a general purpose (non-disease-specific) computational/artificial intelligence (AI) framework to address these challenges. This serves two potential functions: 1) a simulation environment for expl...

  8. Tuning permanent magnets with adjustable field clamps

    International Nuclear Information System (INIS)

    Schermer, R.I.

    1987-01-01

    The effective length of a permanent-magnet assembly can be varied by adjusting the geometrical parameters of a field clamp. This paper presents measurements on a representative dipole and quadrupole as the field clamp is withdrawn axially or radially. The detailed behavior depends upon the magnet multipolarity and geometry. As a rule-of-thumb, a 3-mm-thick iron plate placed at one end plane of the magnet will shorten the length by one-third of the magnet bore radius

  9. Estimation on the clamping force of high strength bolt by temperature parameter

    International Nuclear Information System (INIS)

    Nah, Hwan-Seon; Kim, Kang-Seok; Lee, Hyeon-Ju; Kim, Woo-Bum

    2009-01-01

    In case of Korean nuclear power plant, the field design of bolted connection for steel structures has been changed from high strength hexagon bolt to torque shear bolt. The torque control method is mainly used as a clamping method of high strength bolt at construction site. However the torque coefficient affects the design strength in tension on the process of tightening by torque control. This is why it is obscure to assume quantitatively the direct tension induced into bolt. The determinant factor affected on the clamping force is ambient temperature as Korean standard B 2819 indicated. This study was planned to assess the expected clamping force on two kinds of high strength bolts considering temperature ranged from -10degC to 50degC. From test data subjected to temperature parameters, the equation to estimate the clamping force was extracted by regression analysis. (author)

  10. Algorithms for a Single Hormone Closed-Loop Artificial Pancreas: Challenges Pertinent to Chemical Process Operations and Control

    Directory of Open Access Journals (Sweden)

    B. Wayne Bequette

    2016-10-01

    Full Text Available The development of a closed-loop artificial pancreas to regulate the blood glucose concentration of individuals with type 1 diabetes has been a focused area of research for over 50 years, with rapid progress during the past decade. The daily control challenges faced by someone with type 1 diabetes include asymmetric objectives and risks, and one-sided manipulated input action with frequent relatively fast disturbances. The major automation steps toward a closed-loop artificial pancreas include (i monitoring and overnight alarms for hypoglycemia (low blood glucose; (ii overnight low glucose suspend (LGS systems to prevent hypoglycemia; and (iii fully closed-loop systems that adjust insulin (and perhaps glucagon to maintain desired blood glucose levels day and night. We focus on the steps that we used to develop and test a probabilistic, risk-based, model predictive control strategy for a fully closed-loop artificial pancreas. We complete the paper by discussing ramifications of lessons learned for chemical process systems applications.

  11. Formation of Apatite Coatings on an Artificial Ligament Using a Plasma- and Precursor-Assisted Biomimetic Process

    Directory of Open Access Journals (Sweden)

    Ayako Oyane

    2013-09-01

    Full Text Available A plasma- and precursor-assisted biomimetic process utilizing plasma and alternate dipping treatments was applied to a Leed-Keio artificial ligament to produce a thin coating of apatite in a supersaturated calcium phosphate solution. Following plasma surface modification, the specimen was alternately dipped in calcium and phosphate ion solutions three times (alternate dipping treatment to create a precoating containing amorphous calcium phosphate (ACP which is an apatite precursor. To grow an apatite layer on the ACP precoating, the ACP-precoated specimen was immersed for 24 h in a simulated body fluid with ion concentrations approximately equal to those in human blood plasma. The plasma surface modification was necessary to create an adequate apatite coating and to improve the coating adhesion depending on the plasma power density. The apatite coating prepared using the optimized conditions formed a thin-film that covered the entire surface of the artificial ligament. The resulting apatite-coated artificial ligament should exhibit improved osseointegration within the bone tunnel and possesses great potential for use in ligament reconstructions.

  12. ANALYTICAL BENDING SOLUTION OF ALL CLAMPED ISOTROPIC ...

    African Journals Online (AJOL)

    The analytical bending solution of all clamped rectangular plate on Winkler foundation using characteristic orthogonal polynomials (COPs) was studied. This was achieved by partially integrating the governing differential equation of rectangular plate on elastic foundation four times with respect to its independents x and y ...

  13. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...

  14. AN ACTIVE VALVE WITH A CLAMPED MEMBRANE

    DEFF Research Database (Denmark)

    2009-01-01

    An active valve for use e.g. in fluidic microsystems is provided, wherein the active valve comprises a membrane having at least one flow gate, arranged between a first and a second substantially rigid element. Adjusting means provides an adjustment of the clamping force on membrane arranged between...

  15. Clamp and Gas Nozzle for TIG Welding

    Science.gov (United States)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  16. VELO Module Production - Cable and Clamp Attachment

    CERN Document Server

    Smith, N A

    2007-01-01

    This note describes in detail the procedures used in the fixing of the clamps to hold the cables in position on the pedestal in the final module assembly for the LHCb VELO detector modules. It summarizes the effects on the module of applying the cables.

  17. Cerebral haemodynamics during carotid cross-clamping.

    Science.gov (United States)

    Pistolese, G R; Ippoliti, A; Appolloni, A; Ronchey, S; Faraglia, V

    1993-03-01

    Carotid artery cross-clamping ischaemia during carotid endarterectomy (CEA) causes 5-30% of perioperative neurological deficits. This study was performed to identify possible clinical situations at higher risk for carotid cross-clamping ischaemia. 606 consecutive patients underwent CEA and were retrospectively studied; they were grouped according to risk factors, presence of associated vascular diseases, clinical pattern, angiographic and CT scan findings. Stump pressure measurement was provided in all patients, perioperative monitoring during CEA was performed by electroencephalogram (EEG) in 469 (77%) and somatosensorial evoked potentials (SEP) in 137 (23%). Local anaesthesia was used in 88 (14.5%) patients. Ischaemic changes during carotid cross-clamping were registered in 118 patients (19.5%). The incidence of cross-clamping ischaemia was then related to different factors; it affected 5.6% of asymptomatics, 25.4% of patients with fixed stroke and 38.5% of those with stenosis and contralateral occlusion. Angiographic and clinical correlation showed that patients with more severe lesions are mostly affected by clamping ischaemia (up to 55% in those with stroke and stenosis with contralateral occlusion). Age, hypertension and diabetes do not significantly affect incidence of ischaemic changes. Positive CT scan increased this risk; statistical relevance was found in regard to patients with unilateral or bilateral stenosis and in those with transient ischaemic attacks. A higher risk can be expected for subjects with more severe clinical and instrumental findings, even if no patients can be considered completely at risk or risk free. Perioperative monitoring is always mandatory and is of great importance in detecting ischaemic changes and preventing cerebral damage using a temporary intraluminal shunt.

  18. Detection and location of pipe damage by artificial-neural-net-processed moire error maps

    Science.gov (United States)

    Grossman, Barry G.; Gonzalez, Frank S.; Blatt, Joel H.; Cahall, Scott C.

    1993-05-01

    A novel automated inspection technique to recognize, locate, and quantify damage is developed. This technique is based on two already existing technologies: video moire metrology and artificial neural networks. Contour maps generated by video moire techniques provide an accurate description of surface structure that can then be automated by means of neutral networks. Artificial neural networks offer an attractive solution to the automated interpretation problem because they can generalize from the learned samples and provide an intelligent response for similar patterns having missing or noisy data. Two dimensional video moire images of pipes with dents of different depths, at several rotations, were used to train a multilayer feedforward neural network by the backpropagation algorithm. The backpropagation network is trained to recognize and classify the video moire images according to the dent's depth. Once trained, the network outputs give an indication of the probability that a dent has been found, a depth estimate, and the axial location of the center of the dent. This inspection technique has been demonstrated to be a powerful tool for the automatic location and quantification of structural damage, as illustrated using dented pipes.

  19. Pipe clamp effects on thin-walled pipe design

    International Nuclear Information System (INIS)

    Lindquist, M.R.

    1980-01-01

    Clamp induced stresses in FFTF piping are sufficiently large to require structural assessment. The basic principles and procedures used in analyzing FFTF piping at clamp support locations for compliance with ASME Code rules are given. Typical results from a three-dimensional shell finite element pipe model with clamp loads applied over the clamp/pipe contact area are shown. Analyses performed to categorize clamp induced piping loads as primary or secondary in nature are described. The ELCLAMP Computer Code, which performs analyses at clamp locations combining clamp induced stresses with stresses from overall piping system loads, is discussed. Grouping and enveloping methods to reduce the number of individual clamp locations requiring analysis are described

  20. Mechanical and metallurgical properties of carotid artery clamps.

    Science.gov (United States)

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  1. Traceability of honey origin based on volatiles pattern processing by artificial neural networks.

    Science.gov (United States)

    Cajka, Tomas; Hajslova, Jana; Pudil, Frantisek; Riddellova, Katerina

    2009-02-27

    Head-space solid-phase microextraction (HS-SPME)-based procedure, coupled to comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC-TOF-MS), was employed for fast characterisation of honey volatiles. In total, 374 samples were collected over two production seasons in Corsica (n=219) and other European countries (n=155) with the emphasis to confirm the authenticity of the honeys labelled as "Corsica" (protected denomination of origin region). For the chemometric analysis, artificial neural networks with multilayer perceptrons (ANN-MLP) were tested. The best prediction (94.5%) and classification (96.5%) abilities of the ANN-MLP model were obtained when the data from two honey harvests were aggregated in order to improve the model performance compared to separate year harvests.

  2. Supporting the personnel reliability decision-making process with artificial intelligence

    International Nuclear Information System (INIS)

    Harte, D.C.

    1991-01-01

    Recent legislation concerning personnel security has vastly increased the responsibility and accountability of the security manager. Access authorization, fitness for duty, and personnel security access programs require decisions regarding an individual's trustworthiness and reliability based on the findings of a background investigation. While these guidelines provide significant data and are useful as a tool, limited resources are available to the adjudicator of derogatory information on what is and is not acceptable in terms of granting access to sensitive areas of nuclear plants. The reason why one individual is deemed unacceptable and the next acceptable may be questioned and cause discriminatory accusations. This paper is continuation of discussion on workforce reliability, focusing on the use of artificial intelligence to support the decisions of a security manager. With this support, the benefit of previous decisions helps ensure consistent adjudication of background investigations

  3. Hybrid response surface methodology-artificial neural network optimization of drying process of banana slices in a forced convective dryer.

    Science.gov (United States)

    Taheri-Garavand, Amin; Karimi, Fatemeh; Karimi, Mahmoud; Lotfi, Valiullah; Khoobbakht, Golmohammad

    2017-01-01

    The aim of the study is to fit models for predicting surfaces using the response surface methodology and the artificial neural network to optimize for obtaining the maximum acceptability using desirability functions methodology in a hot air drying process of banana slices. The drying air temperature, air velocity, and drying time were chosen as independent factors and moisture content, drying rate, energy efficiency, and exergy efficiency were dependent variables or responses in the mentioned drying process. A rotatable central composite design as an adequate method was used to develop models for the responses in the response surface methodology. Moreover, isoresponse contour plots were useful to predict the results by performing only a limited set of experiments. The optimum operating conditions obtained from the artificial neural network models were moisture content 0.14 g/g, drying rate 1.03 g water/g h, energy efficiency 0.61, and exergy efficiency 0.91, when the air temperature, air velocity, and drying time values were equal to -0.42 (74.2 ℃), 1.00 (1.50 m/s), and -0.17 (2.50 h) in the coded units, respectively.

  4. 21 CFR 876.5160 - Urological clamp for males.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for males. (a) Identification. A urological clamp for males is a device used to close the urethra of a male to...

  5. 21 CFR 882.5175 - Carotid artery clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Carotid artery clamp. 882.5175 Section 882.5175...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5175 Carotid artery clamp. (a) Identification. A carotid artery clamp is a device that is surgically placed around a patient's carotid artery...

  6. High-speed dynamic-clamp interface

    Science.gov (United States)

    Yang, Yang; Adowski, Timothy; Ramamurthy, Bina; Neef, Andreas

    2015-01-01

    The dynamic-clamp technique is highly useful for mimicking synaptic or voltage-gated conductances. However, its use remains rare in part because there are few systems, and they can be expensive and difficult for less-experienced programmers to implement. Furthermore, some conductances (such as sodium channels) can be quite rapid or may have complex voltage sensitivity, so high speeds are necessary. To address these issues, we have developed a new interface that uses a common personal computer platform with National Instruments data acquisition and WaveMetrics IGOR to provide a simple user interface. This dynamic clamp implements leak and linear synaptic conductances as well as a voltage-dependent synaptic conductance and kinetic channel conductances based on Hodgkin-Huxley or Markov models. The speed of the system can be assayed using a testing mode, and currently speeds of >100 kHz (10 μs per cycle) are achievable with short latency and little jitter. PMID:25632075

  7. Influence of commercial copper microstructure on the artificial green patina formation processes

    Directory of Open Access Journals (Sweden)

    Vera, R.

    1997-12-01

    Full Text Available Commercial copper was submitted to a thermomechanical treatment in order to study its influence on the velocity of artificial green patina formation by immersion as well as on the thickness and adherence of the corrosion product formed on the underlying metal. The thermomechanical treatment enabled us to obtain samples with 9 to 60 μm grain size. These samples were submitted to an accelerated attack by immersion in an electrolytic bath in order to obtain a green patina. On the smallest grain size material it can be observed a patina with high thickness and adherence, smooth texture and homogeneous morphology. From the electrochemical assays it was established that the passivity current decreases for decreasing grain sizes. These results are consistent with the minimal porosity presented by the patina morphology which increase the protecting power. The underlying material did not present localized attack.

    El cobre comercial se sometió a tratamiento termomecánico a fin de estudiar su influencia sobre la velocidad de formación artificial de pátina verde por inmersión, así como sobre el espesor y adherencia al sustrato metálico de los productos de corrosión formados. El tratamiento termomecánico permitía la obtención de muestras de 9 a 60 μm de tamaño de grano. Estas muestras se sometieron a un ataque acelerado por inmersión en un baño electrolítico para obtener la pátina verde. Sobre el material de menor tamaño de grano se puede observar una pátina de elevado espesor y gran adherencia, textura fina y morfología homogénea. A partir de los ensayos electroquímicos se estableció que la corriente de pasivación disminuía para tamaños de grano decrecientes. Estos resultados son consecuentes con la pequeña porosidad presentada por la pátina, lo que incrementa su valor protector. El material subyacente no presentó ataque localizado.

  8. Natural and artificial radionuclides in forest and bog soils: tracers for migration processes and soil development

    International Nuclear Information System (INIS)

    Schleich, N.; Degering, D.; Unterricker, S.

    2000-01-01

    Radionuclide distributions in undisturbed forest and bog soils, mostly situated in Saxony, Germany (Erzgebirge), were studied. Low concentrations of naturally-occurring U and Th decay series nuclides, including 210 Pb, and artificial radioisotopes ( 125 Sb, 134 Cs, 137 Cs, 241 Am) were determined using low-level γ-spectrometry. In addition, the activities of 238 Pu and 239,240 Pu were determined by radiochemical separation and α-spectrometry. 14 C and excess 210 Pb dating methods were used to date the sampled bog profiles. The different radionuclides show characteristic depth distributions in the forest and bog soil horizons, which were sub-sampled as thin slices. 125 Sb, 241 Am, 238 Pu and 239,240 Pu are strongly fixed in soil organic matter. In spruce forest soils, the influence of soil horizons with distinct properties dominates the vertical time-dependent distribution. In ombrotrophic bogs, the peak positions correlated with the year of maximum input of each nuclide. The Sb, Am and Pu ''time markers'' and the 14 C and 210 Pb dating results correspond very well. Although Cs seems to be relatively mobile in organic as well as mineral forest soil horizons, it is enriched in the organic material. In ombrotrophic bogs, Cs is very mobile in the peat deposit. In Sphagnum peat, Cs is translocated continuously towards the growing apices of the Sphagnum mosses, where it is accumulated. (orig.)

  9. Nanopore formation process in artificial cell membrane induced by plasma-generated reactive oxygen species.

    Science.gov (United States)

    Tero, Ryugo; Yamashita, Ryuma; Hashizume, Hiroshi; Suda, Yoshiyuki; Takikawa, Hirofumi; Hori, Masaru; Ito, Masafumi

    2016-09-01

    We investigated morphological change of an artificial lipid bilayer membrane induced by oxygen radicals which were generated by non-equilibrium atmospheric pressure plasma. Neutral oxygen species, O((3)Pj) and O2((1)Δg), were irradiated of a supported lipid bilayer existing under a buffer solution at various conditions of dose time and distances, at which the dose amounts of the oxygen species were calculated quantitatively. Observation using an atomic force microscope and a fluorescence microscope revealed that dose of the neutral oxygen species generated nanopores with the diameter of 10-50 nm in a phospholipid bilayer, and finally destructed the bilayer structure. We found that protrusions appeared on the lipid bilayer surface prior to the formation of nanopores, and we attributed the protrusions to the precursor of the nanopores. We propose a mechanism of the pore formation induced by lipid oxidation on the basis of previous experimental and theoretical studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Detecting and Predicting Muscle Fatigue during Typing By SEMG Signal Processing and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Elham Ghoochani

    2011-03-01

    Full Text Available Introduction: Repetitive strain injuries are one of the most prevalent problems in occupational diseases. Repetition, vibration and bad postures of the extremities are physical risk factors related to work that can cause chronic musculoskeletal disorders. Repetitive work on a computer with low level contraction requires the posture to be maintained for a long time, which can cause muscle fatigue. Muscle fatigue in shoulders and neck is one of the most prevalent problems reported with computer users especially during typing. Surface electromyography (SEMG signals are used for detecting muscle fatigue as a non-invasive method. Material and Methods: Nine healthy females volunteered for signal recoding during typing. EMG signals were recorded from the trapezius muscle, which is subjected to muscle fatigue during typing.  After signal analysis and feature extraction, detecting and predicting muscle fatigue was performed by using the MLP artificial neural network. Results: Recorded signals were analyzed in time and frequency domains for feature extraction. Results of classification showed that the MLP neural network can detect and predict muscle fatigue during typing with 80.79 % ± 1.04% accuracy. Conclusion: Intelligent classification and prediction of muscle fatigue can have many applications in human factors engineering (ergonomics, rehabilitation engineering and biofeedback equipment for mitigating the injuries of repetitive works.

  11. Reasons of unauthorized use of artificial colors in food preparation with Analytical Hierarchy Process (orginal reserch article

    Directory of Open Access Journals (Sweden)

    Reza Khosravi Mashizi

    2016-05-01

    Full Text Available The unauthorized use of synthetic dyes in food has raised health concerns. Determining the reasons of unauthorized use of them can facilitate management and control actions and it also can be important step to protect the health of the community. A questionnaire on the Analytic Hierarchy Process was used to collect views of 138 persons of food staff in Kerman and health experts about the reasons for unauthorized use of artificial colors. Both health experts and staff believed that the most important reason of unauthorized use of artificial colors is economic criteria and the second criterion is awareness. Although cheaper synthetic dyes and low public awareness were selected by experts as the most important sub-criteria, client friendly and low awareness of food staff were selected by food staff. Economy and low awareness are the most important criteria for the unauthorized use of synthetic dyes, so increasing public and food staff awareness can be useful to decline unauthorized use of synthetic dyes. Effective inspection and dealing decisively with offenders, food labeling and controlled distribution of synthetic dyes also can help management of health problems.

  12. Artificial vision.

    Science.gov (United States)

    Zarbin, M; Montemagno, C; Leary, J; Ritch, R

    2011-09-01

    A number treatment options are emerging for patients with retinal degenerative disease, including gene therapy, trophic factor therapy, visual cycle inhibitors (e.g., for patients with Stargardt disease and allied conditions), and cell transplantation. A radically different approach, which will augment but not replace these options, is termed neural prosthetics ("artificial vision"). Although rewiring of inner retinal circuits and inner retinal neuronal degeneration occur in association with photoreceptor degeneration in retinitis pigmentosa (RP), it is possible to create visually useful percepts by stimulating retinal ganglion cells electrically. This fact has lead to the development of techniques to induce photosensitivity in cells that are not light sensitive normally as well as to the development of the bionic retina. Advances in artificial vision continue at a robust pace. These advances are based on the use of molecular engineering and nanotechnology to render cells light-sensitive, to target ion channels to the appropriate cell type (e.g., bipolar cell) and/or cell region (e.g., dendritic tree vs. soma), and on sophisticated image processing algorithms that take advantage of our knowledge of signal processing in the retina. Combined with advances in gene therapy, pathway-based therapy, and cell-based therapy, "artificial vision" technologies create a powerful armamentarium with which ophthalmologists will be able to treat blindness in patients who have a variety of degenerative retinal diseases.

  13. The plastic instability of clamped-clamped conical thin-walled pipe reducers

    International Nuclear Information System (INIS)

    Awad, Ibrahim; Saleh, Ch.A.R.; Ragab, A.R.

    2016-01-01

    The analytical study for plastic deformation of clamped–clamped conical reducer pipe under internal pressure does not deduce a closed form expression for the pressure at plastic instability. The presented study employs finite element analysis (FEA) to estimate the internal pressure at instability for conical reducers made of different materials and having different dimensional configurations. Forty dimensional configurations, classified as medium type, and five types of materials have been included in the analysis using ABAQUS package. A correlation expression is derived by nonlinear regression to predict the instability pressure. The proposed expression is verified for other dimensional configurations out of the above used forty models and for other materials. Experiments have been conducted by pressurizing conical clamped-clamped reducers until bursting in order to verify the finite element models. Comparison of instability pressures, strains and deflections at specific points along the conical surface shows satisfactory agreement between analysis and experiments. - Highlights: • This study offers a parametric study of the plastic instability pressure of clamped-clamped conical reducers. • A closed form analytical expression for the instability pressure is derived by using nonlinear regression. • The finite element analysis is validated by conducting bursting tests.

  14. Dental dam clamp adaptation method on carved gypsum cast.

    Science.gov (United States)

    Cazacu, N C E

    2014-01-01

    Dental Dam is the safest and most efficient isolation technique in endodontics and restorative dentistry, but it also used in esthetics, orthodontics, prosthetics, pedodontics and periodontology (for teeth immobilization). While in most cases the standard clamps are efficient, in some clinical situations clamp adaptation is mandatory in order to assure a tight contact on the tooth. The purpose of this study is to list the elements of the clamp, which should be modified in order to assure a secure constriction of the clamp on the anchor tooth, by using the carved gypsum cast method. 100 patients were examined, diagnosed and treated for various diagnoses like simple decay, gangrene, chronic apical periodontitis, and endodontic retreatments. The clamps used in this study were produced by Hu-Friedy, Hygenic, KKD, SDI, Hager & Werken. In 10 cases, the anchor tooth did not provide enough stability to the standard clamp--as provided by the producer. Therefore, we have done some adjustments to some of the elements of the clamp: the arch, the wings, the plateau, the active area, and the contact points. In 6 cases, major clamp adaptations on carved gypsum cast were imperative. The classic clamps cannot provide a grip to be enough in all the clinical cases due to the huge variety and position and implantation of the anchor teeth. Therefore, in such situations, the clamps should be adapted in order to provide stability and assure the safe isolation during the treatment. The modified clamps will be useful in similar cases, so they must be kept.

  15. Unequal pressure distribution along the jaws of currently available vascular clamps: do we need a new aortic clamp?

    Science.gov (United States)

    Rylski, Bartosz; Schmid, Claudius; Beyersdorf, Friedhelm; Kari, Fabian Alexander; Kondov, Stoyan; Lutz, Lisa; Werner, Martin; Czerny, Martin; Siepe, Matthias

    2016-06-01

    The pressure along vascular clamp jaws may be unequally distributed, with greater pressure near the clamp hinge than at its top. Such unequal pressure distribution may cause aortic injury, especially in large aortas. We evaluated pressure distribution along different currently availably clamp jaws. Seven descending thoracic aortas from pigs (diameter 2.0-3.0 cm) were plainly dissected and all side arteries closed. Aortas were filled up with water and cross-clamped. The pressure inside the aorta was raised to 100 mmHg and the aorta was clamped so tightly that no water exited from the distal aortic end. Each aorta was clamped seven times at different sites with the following clamps: DeBakey, Satinsky, femoral, iliac, Chitwood, angled handle Fogarty and straight handle Fogarty. The pressure along the clamp jaws was measured with a pressure-detecting film placed between the clamp jaws and aorta. The collagen-fibre disorganization was examined in haemotoxylin-eosin- and Elastica van Gieson-stained tissue samples. The DeBakey clamp revealed the lowest maximum pressure along the clamp jaws after complete aortic occlusion (1.43 ± 0.49 MPa), whereas the Chitwood clamp's pressure was the highest (3.26 ± 1.93 MPa, P clamp displayed the lowest difference between maximum pressures across the jaws (33%), with the greatest difference measured in the iliac (72%) and Chitwood (66%) clamps. The highest collagen-fibre disorganization score was observed in the proximal-to-the-clamp-hinge quartile after clamping with the angled handle Fogarty (2.8 ± 0.4), straight handle Fogarty (2.3 ± 0.8) and Chitwood (2.3 ± 0.5) clamps. The pressure along clamp jaws is unequally distributed in all the currently available vascular clamps. The Chitwood clamp is associated with the highest maximum pressure during complete aortic occlusion and with the most unequal pressure distribution along the jaws. © The Author 2015. Published by Oxford University Press on behalf of the European Association

  16. Microcomputer-based artificial vision support system for real-time image processing for camera-driven visual prostheses

    Science.gov (United States)

    Fink, Wolfgang; You, Cindy X.; Tarbell, Mark A.

    2010-01-01

    It is difficult to predict exactly what blind subjects with camera-driven visual prostheses (e.g., retinal implants) can perceive. Thus, it is prudent to offer them a wide variety of image processing filters and the capability to engage these filters repeatedly in any user-defined order to enhance their visual perception. To attain true portability, we employ a commercial off-the-shelf battery-powered general purpose Linux microprocessor platform to create the microcomputer-based artificial vision support system (μAVS2) for real-time image processing. Truly standalone, μAVS2 is smaller than a deck of playing cards, lightweight, fast, and equipped with USB, RS-232 and Ethernet interfaces. Image processing filters on μAVS2 operate in a user-defined linear sequential-loop fashion, resulting in vastly reduced memory and CPU requirements during execution. μAVS2 imports raw video frames from a USB or IP camera, performs image processing, and issues the processed data over an outbound Internet TCP/IP or RS-232 connection to the visual prosthesis system. Hence, μAVS2 affords users of current and future visual prostheses independent mobility and the capability to customize the visual perception generated. Additionally, μAVS2 can easily be reconfigured for other prosthetic systems. Testing of μAVS2 with actual retinal implant carriers is envisioned in the near future.

  17. Quickprop method to speed up learning process of Artificial Neural Network in money's nominal value recognition case

    Science.gov (United States)

    Swastika, Windra

    2017-03-01

    A money's nominal value recognition system has been developed using Artificial Neural Network (ANN). ANN with Back Propagation has one disadvantage. The learning process is very slow (or never reach the target) in the case of large number of iteration, weight and samples. One way to speed up the learning process is using Quickprop method. Quickprop method is based on Newton's method and able to speed up the learning process by assuming that the weight adjustment (E) is a parabolic function. The goal is to minimize the error gradient (E'). In our system, we use 5 types of money's nominal value, i.e. 1,000 IDR, 2,000 IDR, 5,000 IDR, 10,000 IDR and 50,000 IDR. One of the surface of each nominal were scanned and digitally processed. There are 40 patterns to be used as training set in ANN system. The effectiveness of Quickprop method in the ANN system was validated by 2 factors, (1) number of iterations required to reach error below 0.1; and (2) the accuracy to predict nominal values based on the input. Our results shows that the use of Quickprop method is successfully reduce the learning process compared to Back Propagation method. For 40 input patterns, Quickprop method successfully reached error below 0.1 for only 20 iterations, while Back Propagation method required 2000 iterations. The prediction accuracy for both method is higher than 90%.

  18. Modeling of plasma chemical processes in the artificial ionized layer in the upper atmosphere by the nanosecond corona discharge

    Science.gov (United States)

    Vikharev, A. L.; Gorbachev, A. M.; Ivanov, O. A.; Kolisko, A. L.; Litvak, A. G.

    1993-08-01

    The plasma chemical processes in the corona discharge formed in air by a series of high voltage pulses of nanosecond duration are investigated experimentally. The experimental conditions (reduced electric field, duration and repetition frequency of the pulses, gas pressure in the chamber) modeled the regime of creation of the artificial ionized layer (AIL) in the upper atmosphere by a nanosecond microwave discharge. It was found that in a nanosecond microwave discharge predominantly generation of ozone occurs, and that the production of nitrogen dioxide is not large. The energy expenditures for the generation of one O 3 molecule were about 15 eV. On the basis of the experimental results the prognosis of the efficiency of ozone generation in AIL was made.

  19. Automated business process management – in times of digital transformation using machine learning or artificial intelligence

    OpenAIRE

    Paschek Daniel; Luminosu Caius Tudor; Draghici Anca

    2017-01-01

    The continuous optimization of business processes is still a challenge for companies. In times of digital transformation, faster changing internal and external framework conditions and new customer expectations for fastest delivery and best quality of goods and many more, companies should set up their internal process at the best way. But what to do if framework conditions changed unexpectedly? The purpose of the paper is to analyse how the digital transformation will impact the Business Proc...

  20. Applications of Dynamic Clamp to Cardiac Arrhythmia Research: Role in Drug Target Discovery and Safety Pharmacology Testing

    Directory of Open Access Journals (Sweden)

    Francis A. Ortega

    2018-01-01

    Full Text Available Dynamic clamp, a hybrid-computational-experimental technique that has been used to elucidate ionic mechanisms underlying cardiac electrophysiology, is emerging as a promising tool in the discovery of potential anti-arrhythmic targets and in pharmacological safety testing. Through the injection of computationally simulated conductances into isolated cardiomyocytes in a real-time continuous loop, dynamic clamp has greatly expanded the capabilities of patch clamp outside traditional static voltage and current protocols. Recent applications include fine manipulation of injected artificial conductances to identify promising drug targets in the prevention of arrhythmia and the direct testing of model-based hypotheses. Furthermore, dynamic clamp has been used to enhance existing experimental models by addressing their intrinsic limitations, which increased predictive power in identifying pro-arrhythmic pharmacological compounds. Here, we review the recent advances of the dynamic clamp technique in cardiac electrophysiology with a focus on its future role in the development of safety testing and discovery of anti-arrhythmic drugs.

  1. Application of Automated Image-guided Patch Clamp for the Study of Neurons in Brain Slices.

    Science.gov (United States)

    Wu, Qiuyu; Chubykin, Alexander A

    2017-07-31

    Whole-cell patch clamp is the gold-standard method to measure the electrical properties of single cells. However, the in vitro patch clamp remains a challenging and low-throughput technique due to its complexity and high reliance on user operation and control. This manuscript demonstrates an image-guided automatic patch clamp system for in vitro whole-cell patch clamp experiments in acute brain slices. Our system implements a computer vision-based algorithm to detect fluorescently labeled cells and to target them for fully automatic patching using a micromanipulator and internal pipette pressure control. The entire process is highly automated, with minimal requirements for human intervention. Real-time experimental information, including electrical resistance and internal pipette pressure, are documented electronically for future analysis and for optimization to different cell types. Although our system is described in the context of acute brain slice recordings, it can also be applied to the automated image-guided patch clamp of dissociated neurons, organotypic slice cultures, and other non-neuronal cell types.

  2. Artificial intelligence

    CERN Document Server

    Hunt, Earl B

    1975-01-01

    Artificial Intelligence provides information pertinent to the fundamental aspects of artificial intelligence. This book presents the basic mathematical and computational approaches to problems in the artificial intelligence field.Organized into four parts encompassing 16 chapters, this book begins with an overview of the various fields of artificial intelligence. This text then attempts to connect artificial intelligence problems to some of the notions of computability and abstract computing devices. Other chapters consider the general notion of computability, with focus on the interaction bet

  3. Bingham Sealing and Application in Vacuum Clamping

    Science.gov (United States)

    Yao, S. M.; Teo, Wee Kin; Geng, Zunmin; Turner, Sam; Ridgway, Keith

    2011-12-01

    Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of "O"ring sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with "O" ring sealing.

  4. Bingham Sealing and Application in Vacuum Clamping

    International Nuclear Information System (INIS)

    Yao, S M; Teo, Wee Kin; Geng Zunmin; Turner, Sam; Ridgway, Keith

    2011-01-01

    Vacuum clamping is extensively used in shell machining. In this paper a Bingham Sealing (BS) is presented and formulized based on Bingham plastic performance. The sealing capability of BS is evaluated in various cases. A new Bingham plastic is developed and the yield stress is measured. The performances of Or ing sealing and BS with the developed Bingham plastic are compared to the static experiment. In this experiment the same vacuum is achieved and the distortion of the blade with BS is better than that with 'O' ring sealing.

  5. Introduction of artificial intelligence techniques for computerized management of defects in an industrial process

    International Nuclear Information System (INIS)

    Utzel, N.

    1991-06-01

    An optimized management of Tore Supra Tokamak requires a computerized defect management. The aim is the analysis of an inhibited situation not corrected by automatisms of the process and that can be handled only by human intervention. The operator should understand, make a diagnosis and act to restore the system. In this report are studied an expert system helping the operator to analyze defects of the two main cooling loops (decarbonated water and pressurized water), management of the history of malfunction and recording of diagnosises, elaboration of an adapted expert model and installation of a methodology for defect management in other processes of Tore Supra [fr

  6. Heuristic Analysis Model of Nitrided Layers’ Formation Consisting of the Image Processing and Analysis and Elements of Artificial Intelligence

    Science.gov (United States)

    Wójcicki, Tomasz; Nowicki, Michał

    2016-01-01

    The article presents a selected area of research and development concerning the methods of material analysis based on the automatic image recognition of the investigated metallographic sections. The objectives of the analyses of the materials for gas nitriding technology are described. The methods of the preparation of nitrided layers, the steps of the process and the construction and operation of devices for gas nitriding are given. We discuss the possibility of using the methods of digital images processing in the analysis of the materials, as well as their essential task groups: improving the quality of the images, segmentation, morphological transformations and image recognition. The developed analysis model of the nitrided layers formation, covering image processing and analysis techniques, as well as selected methods of artificial intelligence are presented. The model is divided into stages, which are formalized in order to better reproduce their actions. The validation of the presented method is performed. The advantages and limitations of the developed solution, as well as the possibilities of its practical use, are listed. PMID:28773389

  7. Heuristic Analysis Model of Nitrided Layers' Formation Consisting of the Image Processing and Analysis and Elements of Artificial Intelligence.

    Science.gov (United States)

    Wójcicki, Tomasz; Nowicki, Michał

    2016-04-01

    The article presents a selected area of research and development concerning the methods of material analysis based on the automatic image recognition of the investigated metallographic sections. The objectives of the analyses of the materials for gas nitriding technology are described. The methods of the preparation of nitrided layers, the steps of the process and the construction and operation of devices for gas nitriding are given. We discuss the possibility of using the methods of digital images processing in the analysis of the materials, as well as their essential task groups: improving the quality of the images, segmentation, morphological transformations and image recognition. The developed analysis model of the nitrided layers formation, covering image processing and analysis techniques, as well as selected methods of artificial intelligence are presented. The model is divided into stages, which are formalized in order to better reproduce their actions. The validation of the presented method is performed. The advantages and limitations of the developed solution, as well as the possibilities of its practical use, are listed.

  8. Artificial graphites

    International Nuclear Information System (INIS)

    Maire, J.

    1984-01-01

    Artificial graphites are obtained by agglomeration of carbon powders with an organic binder, then by carbonisation at 1000 0 C and graphitization at 2800 0 C. After description of the processes and products, we show how the properties of the various materials lead to the various uses. Using graphite enables us to solve some problems, but it is not sufficient to satisfy all the need of the application. New carbonaceous material open application range. Finally, if some products are becoming obsolete, other ones are being developed in new applications [fr

  9. Simultaneous and automated monitoring of the multimetal biosorption processes by potentiometric sensor array and artificial neural network.

    Science.gov (United States)

    Wilson, D; del Valle, M; Alegret, S; Valderrama, C; Florido, A

    2013-09-30

    In this communication, a new methodology for the simultaneous and automated monitoring of biosorption processes of multimetal mixtures of polluting heavy metals on vegetable wastes based on flow-injection potentiometry (FIP) and electronic tongue detection (ET) is presented. A fixed-bed column filled with grape stalks from wine industry wastes is used as the biosorption setup to remove the metal mixtures from the influent solution. The monitoring system consists in a computer controlled-FIP prototype with the ET based on an array of 9 flow-through ion-selective electrodes and electrodes with generic response to divalent ions placed in series, plus an artificial neural network response model. The cross-response to Cu(2+), Cd(2+), Zn(2+), Pb(2+) and Ca(2+) (as target ions) is used, and only when dynamic treatment of the kinetic components of the transient signal is incorporated, a correct operation of the system is achieved. For this purpose, the FIA peaks are transformed via use of Fourier treatment, and selected coefficients are used to feed an artificial neural network response model. Real-time monitoring of different binary (Cu(2+)/ Pb(2+)), (Cu(2+)/ Zn(2+)) and ternary mixtures (Cu(2+)/ Pb(2+)/ Zn(2+)), (Cu(2+)/ Zn(2+)/ Cd(2+)), simultaneous to the release of Ca(2+) in the effluent solution, are achieved satisfactorily using the reported system, obtaining the corresponding breakthrough curves, and showing the ion-exchange mechanism among the different metals. Analytical performance is verified against conventional spectroscopic techniques, with good concordance of the obtained breakthrough curves and modeled adsorption parameters. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Robotic clamp and index tool and method for their use in repairing certain elements with in a nuclear reactor

    International Nuclear Information System (INIS)

    Green, R.A.

    1986-01-01

    This patent describes a clamp-and-index tool for use in the replacement of old split-pin assemblies of a guide tube of a nuclear reactor by new split-pin assemblies, the old split-pin assemblies and the guide tube being radioactive and the clamp-and-index tool to operate under a pool of water. The tool includes means, to be connected to the guide tube, for suspending the guide tube in a first position in which the tube is to be processed to effect the replacement. The tool also includes a means, connected to the suspending means, for rotating the guide tube to a second position in which the tube is to be processed to effect the replacement and clamping means, connected to the suspending means and to be connected to the guide tube, for selectively clamping the guide tube in the first or second position

  11. Improving safety and efficiency during emergent central venous catheter placement with a needleless securing clamp.

    Science.gov (United States)

    Silich, Bert; Chrobak, Paul; Siu, Jeffrey; Schlichting, Adam; Patel, Samir; Yang, James

    2013-08-01

    To compare the needleless securing clamp to the traditional suture-secured clamp for central venous catheters. Compare the holding strength of each type of clamps by measuring the amount of kinetic energy absorbed, ask 20 physicians to evaluate the clamp placement using sutures or staples, and summarise the clamps effectiveness and complications in 10 patients. Compared to sutured clamp, the needleless clamp was more secure. The needleless clamp was also significantly better with regard to ease of use, safety, perceived strength (p value clamps. Without incurring complications or increasing risk to patients, the needleless clamp is secure and improves safety and efficiency for physicians.

  12. Natural and artificial aging response of semi-solid metal processed alloy A356

    CSIR Research Space (South Africa)

    Möller, H

    2008-09-01

    Full Text Available The heat treatment cycles that are currently applied to semi-solid processed components are mostly those that are in use for dendritic casting alloys. These heat treatments are not necessarily the optimum treatments for non-dendritic microstructures...

  13. The β Sliding Clamp Closes around DNA prior to Release by the Escherichia coli Clamp Loader γ Complex*

    Science.gov (United States)

    Hayner, Jaclyn N.; Bloom, Linda B.

    2013-01-01

    Escherichia coli γ complex clamp loader functions to load the β sliding clamp onto sites of DNA replication and repair. The clamp loader uses the energy of ATP binding and hydrolysis to drive conformational changes allowing for β binding and opening, DNA binding, and then release of the β·DNA complex. Although much work has been done studying the sliding clamp and clamp loader mechanism, kinetic analysis of the events following β·γ complex·DNA formation is not complete. Using fluorescent clamp closing and release assays, we show that β closing is faster than β release, indicating that γ complex closes β before releasing it around DNA. Using a fluorescent ATP hydrolysis assay, we show that there is a burst of ATP hydrolysis before β closing and that β release may be the rate-limiting step in the overall clamp loading reaction. The combined use of these fluorescent assays provides a unique perspective into the E. coli clamp loader by providing a measure of the relative timing of different events in the clamp loading reaction, helping to elucidate the complicated clamp loading mechanism. PMID:23161545

  14. In vivo fracture of a new rubber-dam clamp.

    Science.gov (United States)

    Zinelis, S; Margelos, J

    2002-08-01

    This study was carried out to investigate the reasons for fracture of a new rubber-dam clamp used for the first time. The fractured surfaces of the broken clamp were studied with optical microscopy. Characteristic surface patterns of tensile fracture were identified. Cracks originated from the groove of letter D mechanically engraved on the inner surface of the clamp bow, and developed with high velocity (unstable crack growth rate) leading to catastrophic fracture. This behaviour was attributed to the residual stresses introduced by the labelling technique due to local thermal alterations. The labelling technique used to number clamps may be implicated with catastrophic failure. Dentists should be aware that even new clamps can fracture. It is important that clamps are secured to prevent inhalation of metal fragments, should catastrophic failure occur.

  15. Design of a hot clamp for small diameter LMFBR piping

    International Nuclear Information System (INIS)

    Jones, J.W.; Hamel, D.

    1980-01-01

    In order to evaluate the feasibility of using a strap-type clamp on breeder reactor small diameter piping, a series of analyses were conducted to determine the thermal and mechanical stresses induced in the pipe by the clamp. The effect of using a thin layer of insulation of varying thickness between the pipe and clamp was also investigated. A thermal analysis of the pipe and clamp was conducted for each thermal transient rate. Various insulation values ranging from metal-to-metal condition to perfect insulation between the pipe and clamp were analyzed to determine the effect of insulating the pipe from the clamp. An axisymmetric finite element model was used to determine the axial thermal and stress patterns

  16. Type IA topoisomerase inhibition by clamp closure.

    Science.gov (United States)

    Leelaram, Majety Naga; Bhat, Anuradha Gopal; Godbole, Adwait Anand; Bhat, Rajeshwari Subray; Manjunath, Ramanathapuram; Nagaraja, Valakunja

    2013-08-01

    Bacterial DNA topoisomerase I (topoI) catalyzes relaxation of negatively supercoiled DNA. The enzyme alters DNA topology through protein-operated DNA gate, switching between open and closed conformations during its reaction. We describe the mechanism of inhibition of Mycobacterium smegmatis and Mycobacterium tuberculosis topoI by monoclonal antibodies (mAbs) that bind with high affinity and inhibit at 10-50 nM concentration. Unlike other inhibitors of topoisomerases, the mAbs inhibited several steps of relaxation reaction, namely DNA binding, cleavage, strand passage, and enzyme-DNA dissociation. The enhanced religation of the cleaved DNA in presence of the mAb indicated closing of the enzyme DNA gate. The formation of enzyme-DNA heterocatenane in the presence of the mAbs as a result of closing the gate could be inferred by the salt resistance of the complex, visualized by atomic force microscopy and confirmed by fluorescence measurements. Locking the enzyme-DNA complex as a closed clamp restricted the movements of the DNA gate, affecting all of the major steps of the relaxation reaction. Enzyme trapped on DNA in closed clamp conformation formed roadblock for the elongating DNA polymerase. The unusual multistep inhibition of mycobacterial topoisomerases may facilitate lead molecule development, and the mAbs would also serve as valuable tools to probe the enzyme mechanism.

  17. Linchpin DNA-binding residues serve as go/no-go controls in the replication factor C-catalyzed clamp-loading mechanism.

    Science.gov (United States)

    Liu, Juan; Zhou, Yayan; Hingorani, Manju M

    2017-09-22

    DNA polymerases depend on circular sliding clamps for processive replication. Clamps must be loaded onto primer-template DNA (ptDNA) by clamp loaders that open and close clamps around ptDNA in an ATP-fueled reaction. All clamp loaders share a core structure in which five subunits form a spiral chamber that binds the clamp at its base in a twisted open form and encloses ptDNA within, while binding and hydrolyzing ATP to topologically link the clamp and ptDNA. To understand how clamp loaders perform this complex task, here we focused on conserved arginines that might play a central coordinating role in the mechanism because they can alternately contact ptDNA or Walker B glutamate in the ATPase site and lie close to the clamp loader-clamp-binding interface. We mutated Arg-84, Arg-88, and Arg-101 in the ATPase-active B, C, and D subunits of Saccharomyces cerevisiae replication factor C (RFC) clamp loader, respectively, and assessed the impact on multiple transient events in the reaction: proliferating cell nuclear antigen (PCNA) clamp binding/opening/closure/release, ptDNA binding/release, and ATP hydrolysis/product release. The results show that these arginines relay critical information between the PCNA-binding, DNA-binding, and ATPase sites at all steps of the reaction, particularly at a checkpoint before RFC commits to ATP hydrolysis. Moreover, their actions are subunit-specific with RFC-C Arg-88 serving as an accelerator that enables rapid ATP hydrolysis upon contact with ptDNA and RFC-D Arg-101 serving as a brake that confers specificity for ptDNA as the correct substrate for loading PCNA. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. Operation of a two-stage continuous fermentation process producing hydrogen and methane from artificial food wastes

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Kohki; Mizuno, Shiho; Umeda, Yoshito; Sakka, Makiko [Toho Gas Co., Ltd. (Japan); Osaka, Noriko [Tokyo Gas Co. Ltd. (Japan); Sakka, Kazuo [Mie Univ. (Japan)

    2010-07-01

    An anaerobic two-stage continuous fermentation process with combined thermophilic hydrogenogenic and methanogenic stages (two-stage fermentation process) was applied to artificial food wastes on a laboratory scale. In this report, organic loading rate (OLR) conditions for hydrogen fermentation were optimized before operating the two-stage fermentation process. The OLR was set at 11.2, 24.3, 35.2, 45.6, 56.1, and 67.3 g-COD{sub cr} L{sup -1} day{sup -1} with a temperature of 60 C, pH5.5 and 5.0% total solids. As a result, approximately 1.8-2.0 mol-H{sub 2} mol-hexose{sup -1} was obtained at the OLR of 11.2-56.1 g-COD{sub cr} L{sup -1} day{sup -1}. In contrast, it was inferred that the hydrogen yield at the OLR of 67.3 g-COD{sub cr} L{sup -1} day{sup -1} decreased because of an increase in lactate concentration in the culture medium. The performance of the two-stage fermentation process was also evaluated over three months. The hydraulic retention time (HRT) of methane fermentation was able to be shortened 5.0 days (under OLR 12.4 g-COD{sub cr} L{sup -1} day{sup -1} conditions) when the OLR of hydrogen fermentation was 44.0 g-COD{sub cr} L{sup -1} day{sup -1}, and the average gasification efficiency of the two-stage fermentation process was 81% at the time. (orig.)

  19. Medial Clamp Tine Positioning Affects Ankle Syndesmosis Malreduction.

    Science.gov (United States)

    Cosgrove, Christopher T; Putnam, Sara M; Cherney, Steven M; Ricci, William M; Spraggs-Hughes, Amanda; McAndrew, Christopher M; Gardner, Michael J

    2017-08-01

    To determine whether the position of the medial clamp tine during syndesmotic reduction affected reduction accuracy. Prospective cohort. Urban Level 1 trauma center. Seventy-two patients with operatively treated syndesmotic injuries. Patients underwent operative fixation of their ankle syndesmotic injuries using reduction forceps. The position of the medial clamp tine was then recorded with intraoperative fluoroscopy. Malreduction rates were then assessed with bilateral ankle computerized tomography. Fibular position within the incisura was measured with respect to the uninjured side to determine whether a malreduction had occurred. Malreductions were then analyzed for associations with injury pattern, patient demographics, and the location of the medial clamp tine. A statistically significant association was found between medial clamp position and sagittal plane syndesmosis malreduction. In reference to anterior fibular translation, there was a 0% malreduction rate in the 18 patients where the clamp tine was placed in the anterior third, a 19.4% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.006). In reference to posterior fibular translation, there was a 11.1% malreduction when clamp placement was in the anterior third, a 16.1% malreduction rate in the middle third, and 60% malreduction rate in the posterior third (P = 0.062). There were no significant associations between medial clamp position and coronal plane malreductions (overcompression or undercompression) (P = 1). When using reduction forceps for syndesmotic reduction, the position of the medial clamp tine can be highly variable. The angle created with off-axis syndesmotic clamping is likely a major culprit in iatrogenic malreduction. Sagittal plane malreduction appears to be highly sensitive to clamp obliquity, which is directly related to the medial clamp tine placement. Based on these data, we recommend placing the medial clamp tine in the anterior third

  20. Mycobacterium tuberculosis class II apurinic/apyrimidinic-endonuclease/3'-5' exonuclease III exhibits DNA regulated modes of interaction with the sliding DNA β-clamp.

    Science.gov (United States)

    Khanam, Taran; Rai, Niyati; Ramachandran, Ravishankar

    2015-10-01

    The class-II AP-endonuclease (XthA) acts on abasic sites of damaged DNA in bacterial base excision repair. We identified that the sliding DNA β-clamp forms in vivo and in vitro complexes with XthA in Mycobacterium tuberculosis. A novel 239 QLRFPKK245 motif in the DNA-binding domain of XthA was found to be important for the interactions. Likewise, the peptide binding-groove (PBG) and the C-terminal of β-clamp located on different domains interact with XthA. The β-clamp-XthA complex can be disrupted by clamp binding peptides and also by a specific bacterial clamp inhibitor that binds at the PBG. We also identified that β-clamp stimulates the activities of XthA primarily by increasing its affinity for the substrate and its processivity. Additionally, loading of the β-clamp onto DNA is required for activity stimulation. A reduction in XthA activity stimulation was observed in the presence of β-clamp binding peptides supporting that direct interactions between the proteins are necessary to cause stimulation. Finally, we found that in the absence of DNA, the PBG located on the second domain of the β-clamp is important for interactions with XthA, while the C-terminal domain predominantly mediates functional interactions in the substrate's presence. © 2015 John Wiley & Sons Ltd.

  1. Modeling of mass transfer of Phospholipids in separation process with supercritical CO2 fluid by RBF artificial neural networks

    Science.gov (United States)

    An artificial Radial Basis Function (RBF) neural network model was developed for the prediction of mass transfer of the phospholipids from canola meal in supercritical CO2 fluid. The RBF kind of artificial neural networks (ANN) with orthogonal least squares (OLS) learning algorithm were used for mod...

  2. Artificial Intelligence In Processing A Sequence Of Time-Varying Images

    Science.gov (United States)

    Siler, W.; Tucker, D.; Buckley, J.; Hess, R. G.; Powell, V. G.

    1985-04-01

    A computer system is described for unsupervised analysis of five sets of ultrasound images of the heart. Each set consists of 24 frames taken at 33 millisecond intervals. The images are acquired in real time with computer control of the ultrasound apparatus. After acquisition the images are segmented by a sequence of image-processing programs; features are extracted and stored in a version of the Carnegie- Mellon Blackboard. Region classification is accomplished by a fuzzy logic expert system FLOPS based on OPS5. Preliminary results are given.

  3. PENGOLAHAN BERAS WANGI BUATAN METODE DAN RETENSI SENYAWA AROMA [Processing of Artificial Fragrant Rice The Method and Aroma Retention

    Directory of Open Access Journals (Sweden)

    Filli Pratama

    2006-08-01

    Full Text Available Processing of artificial fragrant rice in which one or more aroma compounds were introduced into raw milled rice were studied. The end product, which is potentially marketable, showed no visible difference in appearance from the untreated rice, and the cooked product showed perceivable aroma to the consumers. The aromatisation process used liquid carbon dioxide as a vehicle to deliver the aroma. Five aroma compounds of eugenol, iso-eugenol, methyl eugenol, cinnamyl alcohol, and cinnamaldehyde were used as model compounds. The results showed that liquid carbon dioxide at a pressure of 8 MPa and an equilibration time of 5 minutes were found to be the optimum conditions for imparting the aroma compounds into the rice. The retention of the model aroma compounds in rice were in the range of 33% to 50%. The aroma carrier was found to be able to carry the model compounds into the core of rice. This was significant, as it potentially provided a longer period for the aroma compounds to remain in the rice.

  4. The use of artificial neural network for modeling the decolourization of acid orange 7 solution of industrial by ozonation process

    Science.gov (United States)

    Fatimah, S.; Wiharto, W.

    2017-02-01

    Acid Orange 7 (AO7) is one of the synthetic dye in the dyeing process in the textile industry. The use of this dye can produce wastewater which will be endangered if not treated well. Ozonation method is one technique to solve this problem. Ozonation is a waste processing techniques using ozone as an oxidizing agent. Variables used in this research is the ozone concentration, the initial concentration of AO7, temperature, and pH. Based on the experimental result that the optimum value decolourization percentage is 80% when the ozone concentration is 560 mg/L, the initial concentration AO7 is 14 mg/L, the temperature is 390 °C, and pH is 7,6. Decolourization efficiency of experimental results and predictions successfully modelled by the neural network architecture. The data used to construct a neural network architecture quasi newton one step secant as many as 31 data. A comparison between the predicted results of the designed ANN models and experiment was conducted. From the modeling results obtained MAPE value of 0.7763%. From the results of this artificial neural network architecture obtained the optimum value decolourization percentage in 80,64% when the concentration of ozone is 550 mg/L, the initial concentration AO7 is 11 mg/L, the temperature is 41 °C, and the pH is 7.9.

  5. Obstetricians' attitudes and beliefs regarding umbilical cord clamping.

    Science.gov (United States)

    Jelin, Angie C; Kuppermann, Miriam; Erickson, Kristine; Clyman, Ronald; Schulkin, Jay

    2014-09-01

    Although delayed umbilical cord clamping has been demonstrated to reduce the incidence of intraventricular hemorrhage and neonatal sepsis, and decrease the need for neonatal transfusions (without affecting cord pH, Apgar scores or the need for phototherapy), the extent to which this practice is being employed is unknown. We conducted a survey of US obstetricians to assess their attitudes and beliefs about cord clamping. Questionnaires were randomly mailed to members of the American College of Obstetricians and Gynecologists (ACOG), and the Collaborative Ambulatory Research Network (CARN). The data were analyzed using Chi-square and Student t tests. The response rates for the CARN and other ACOG members were 47% and 21%, respectively. Most (88%) responders reported their hospital had no umbilical cord clamping policy. The most frequent response for optimal timing of umbilical cord clamping, regardless of gestational age, was "don't know". Potential for neonatal red blood cell transfusion was the only concern cited as a reason for being somewhat or very inclined to delay umbilical cord clamping (51%). Delayed neonatal resuscitation (76%) was listed as a reason to clamp the cord immediately, despite the paucity of literature to support immediate cord clamping in this cohort. Despite substantial evidence supporting the practice of delayed cord clamping, few institutions have policies regarding this practice. Moreover, obstetricians' beliefs about the appropriate timing for umbilical cord clamping are not consistent with the evidence that demonstrates its beneficial impact on neonatal outcomes.

  6. E. coli DNA replication in the absence of free beta clamps

    NARCIS (Netherlands)

    Tanner, Nathan A.; Tolun, Goekhan; Loparo, Joseph J.; Jergic, Slobodan; Griffith, Jack D.; Dixon, Nicholas E.; van Oijen, Antoine M.

    2011-01-01

    During DNA replication, repetitive synthesis of discrete Okazaki fragments requires mechanisms that guarantee DNA polymerase, clamp, and primase proteins are present for every cycle. In Escherichia coli, this process proceeds through transfer of the lagging-strand polymerase from the beta sliding

  7. PRELIMINARY MODELING OF AN INDUSTRIAL RECOMBINANT HUMAN ERYTHROPOIETIN PURIFICATION PROCESS BY ARTIFICIAL NEURAL NETWORKS

    Directory of Open Access Journals (Sweden)

    R. H. R. Garcel1

    2015-09-01

    Full Text Available AbstractIn the present study a preliminary neural network modelling to improve our understanding of Recombinant Human Erythropoietin purification process in a plant was explored. A three layer feed-forward back propagation neural network was constructed for predicting the efficiency of the purification section comprising four chromatographic steps as a function of eleven operational variables. The neural network model performed very well in the training and validation phases. Using the connection weight method the predictor variables were ranked based on their estimated explanatory importance in the neural network and five input variables were found to be predominant over the others. These results provided useful information showing that the first chromatographic step and the third chromatographic step are decisive to achieve high efficiencies in the purification section, thus enriching the control strategy of the plant.

  8. Modelling and Predicting the Breaking Strength and Mass Irregularity of Cotton Rotor-Spun Yarns Containing Cotton Fiber Recovered from Ginning Process by Using Artificial Neural Network Algorithm

    Directory of Open Access Journals (Sweden)

    Mohsen Shanbeh

    2011-01-01

    Full Text Available One of the main methods to reduce the production costs is waste recycling which is the most important challenge for the future. Cotton wastes collected from ginning process have desirable properties which could be used during spinning process. The purpose of this study was to develop predictive models of breaking strength and mass irregularity (CV% of cotton waste rotor-spun yarns containing cotton waste collected from ginning process by using the artificial neural network trained with backpropagation algorithm. Artificial neural network models have been developed based on rotor diameter, rotor speed, navel type, opener roller speed, ginning waste proportion and yarn linear density as input parameters. The parameters of artificial neural network model, namely, learning, and momentum rate, number of hidden layers and number of hidden processing elements (neurons were optimized to get the best predictive models. The findings showed that the breaking strength and mass irregularity of rotor spun yarns could be predicted satisfactorily by artificial neural network. The maximum error in predicting the breaking strength and mass irregularity of testing data was 8.34% and 6.65%, respectively.

  9. Optimizing stabilization of waste-activated sludge using Fered-Fenton process and artificial neural network modeling (KSOFM, MLP).

    Science.gov (United States)

    Badalians Gholikandi, Gagik; Masihi, Hamidreza; Azimipour, Mohammad; Abrishami, Ali; Mirabi, Maryam

    2014-01-01

    Sludge management is a fundamental activity in accordance with wastewater treatment aims. Sludge stabilization is always considered as a significant step of wastewater sludge handling. There has been a progressive development observed in the approach to the novel solutions in this regard. In this research, based on own initially experimental results in lab-scale regarding Fered-Fenton processes in view of organic loading (volatile-suspended solids, VSS) removal efficiency, a combination of both methods towards proper improving of excess biological sludge stabilization was investigated. Firstly, VSS removal efficiency has been experimentally studied in lab-scale under different operational conditions taking into consideration pH [Fe(2+)]/[H2O2], detention time [H2O2], and current density parameters. Therefore, the correlations of the same parameters have been determined by utilizing Kohonen self-organizing feature maps (KSOFM). In addition, multi-layer perceptron (MLP) has been employed afterwards for a comprehensive evaluation of investigating parameters correlation and prediction aims. The findings indicated that the best proportion of iron to hydrogen peroxide and the optimum pH were 0.58 and 3.1, respectively. Furthermore, maximum retention time about 6 h with a hydrogen peroxide concentration of 1,568 mg/l and a current density of 650-750 mA results to the optimum VSS removal (efficiency equals to 81 %). The performance of KSOFM and MLP models is found to be magnificent, with correlation ranging (R) from 0.873 to 0.998 for the process simulation and prediction. Finally, it can be concluded that the Fered-Fenton reactor is a suitable efficient process to reduce considerably sludge organic load and mathematical modeling tools as artificial neural networks are impressive methods of process simulation and prediction accordingly.

  10. Artificial Neural Networks in Image Processing for Early Detection of Breast Cancer

    Directory of Open Access Journals (Sweden)

    M. M. Mehdy

    2017-01-01

    Full Text Available Medical imaging techniques have widely been in use in the diagnosis and detection of breast cancer. The drawback of applying these techniques is the large time consumption in the manual diagnosis of each image pattern by a professional radiologist. Automated classifiers could substantially upgrade the diagnosis process, in terms of both accuracy and time requirement by distinguishing benign and malignant patterns automatically. Neural network (NN plays an important role in this respect, especially in the application of breast cancer detection. Despite the large number of publications that describe the utilization of NN in various medical techniques, only a few reviews are available that guide the development of these algorithms to enhance the detection techniques with respect to specificity and sensitivity. The purpose of this review is to analyze the contents of recently published literature with special attention to techniques and states of the art of NN in medical imaging. We discuss the usage of NN in four different medical imaging applications to show that NN is not restricted to few areas of medicine. Types of NN used, along with the various types of feeding data, have been reviewed. We also address hybrid NN adaptation in breast cancer detection.

  11. Artificial Neural Networks in Image Processing for Early Detection of Breast Cancer.

    Science.gov (United States)

    Mehdy, M M; Ng, P Y; Shair, E F; Saleh, N I Md; Gomes, C

    2017-01-01

    Medical imaging techniques have widely been in use in the diagnosis and detection of breast cancer. The drawback of applying these techniques is the large time consumption in the manual diagnosis of each image pattern by a professional radiologist. Automated classifiers could substantially upgrade the diagnosis process, in terms of both accuracy and time requirement by distinguishing benign and malignant patterns automatically. Neural network (NN) plays an important role in this respect, especially in the application of breast cancer detection. Despite the large number of publications that describe the utilization of NN in various medical techniques, only a few reviews are available that guide the development of these algorithms to enhance the detection techniques with respect to specificity and sensitivity. The purpose of this review is to analyze the contents of recently published literature with special attention to techniques and states of the art of NN in medical imaging. We discuss the usage of NN in four different medical imaging applications to show that NN is not restricted to few areas of medicine. Types of NN used, along with the various types of feeding data, have been reviewed. We also address hybrid NN adaptation in breast cancer detection.

  12. Effect of process variables on the preparation of artificial bone cements

    Energy Technology Data Exchange (ETDEWEB)

    Santos Junior, J.G.F.; Melo, P.A.; Pinto, J.C., E-mail: pinto@peq.coppe.ufrj.br, E-mail: jjunior@peq.coppe.ufrj.br, E-mail: melo@peq.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Quimica; Pita, V.J.R.R., E-mail: vjpita@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Macromoleculas; Nele, M., E-mail: nele@eq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2013-10-15

    The present work concerns the preparation of bone cements based on poly(methyl methacrylate) (PMMA), used mainly for prosthesis fixation and cavity filling for correction of human bone failures. A typical bone cement recipe contains methyl methacrylate, which polymerizes in situ during cement application. An inherent problem of this reaction is the large amount of heat released during the cement preparation, which may lead to irreparable damage of living tissues. Optimization of PMMA-based bone cement recipes is thus an important step towards safe and reliable clinical usage of these materials. Important process variables related to the reaction temperature profile and the mixing of the recipe constituents were studied in order to allow for the adequate production of bone cements. It is shown that the average molar mass and size of the PMMA particles used in the production of the bone cement, as well as incorporation of radiopaque contrast, co-monomers and fillers into the bone recipe play fundamental roles in the course of the polymerization reaction. Furthermore, the injection vessel geometry may interfere dramatically with the temperature profile and the time for its occurrence. Finally, it has been observed that the morphology of the PMMA particles strongly affects the mixing of the bone cement components. (author)

  13. Off-Clamp versus On-Clamp Robotic Partial Nephrectomy: A Multicenter Match-Paired Case-Control Study.

    Science.gov (United States)

    Peyronnet, Benoit; Khene, Zine-Eddine; Pradère, Benjamin; Seisen, Thomas; Verhoest, Grégory; Masson-Lecomte, Alexandra; Grassano, Yohann; Roumiguié, Mathieu; Beauval, Jean-Baptiste; Baumert, Hervé; Droupy, Stéphane; Doumerc, Nicolas; Bernhard, Jean-Christophe; Vaessen, Christophe; Bruyère, Franck; de la Taille, Alexandre; Rouprêt, Morgan; Bensalah, Karim

    2017-01-01

    The aim of this study was to compare the outcomes of on-clamp and off-clamp robotic partial nephrectomy (RPN). The charts of all patients who underwent an RPN at 8 institutions between 2010 and 2014 were retrospectively reviewed. The patients who underwent an off-clamp RPN were matched to on-clamp RPN in a 1-4 fashion according to the following variables: RENAL score, tumor size and surgeon's experience. Pre-, intra-, and postoperative data were compared between both groups. Among 525 RPN, 26 were performed off-clamp (5%). They were matched to 104 on-clamp RPN. The complications rate (15.5 vs. 7.7%, p = 0.53), major complications rate (4.9 vs. 3.9%; p = 0.82), and transfusions rate (0 vs. 4.9%; p = 0.58) did not differ significantly between the clamped and unclamped groups. Conversely, estimated blood loss was higher in the off-clamp group (266.4 vs. 284.6 mL, p = 0.048) and so was the rate of conversion to radical nephrectomy (0 vs. 7.7%, p = 0.04). Postoperative preservation of renal function was comparable in both groups. Off-clamp RPN is feasible for a small subgroup of renal tumors without increased risk of postoperative complications but at the cost of higher estimated blood loss and increased risk of conversion to radical nephrectomy. © 2017 S. Karger AG, Basel.

  14. Catch and Patch: A Pipette-Based Approach for Automating Patch Clamp That Enables Cell Selection and Fast Compound Application.

    Science.gov (United States)

    Danker, Timm; Braun, Franziska; Silbernagl, Nikole; Guenther, Elke

    2016-03-01

    Manual patch clamp, the gold standard of electrophysiology, represents a powerful and versatile toolbox to stimulate, modulate, and record ion channel activity from membrane fragments and whole cells. The electrophysiological readout can be combined with fluorescent or optogenetic methods and allows for ultrafast solution exchanges using specialized microfluidic tools. A hallmark of manual patch clamp is the intentional selection of individual cells for recording, often an essential prerequisite to generate meaningful data. So far, available automation solutions rely on random cell usage in the closed environment of a chip and thus sacrifice much of this versatility by design. To parallelize and automate the traditional patch clamp technique while perpetuating the full versatility of the method, we developed an approach to automation, which is based on active cell handling and targeted electrode placement rather than on random processes. This is achieved through an automated pipette positioning system, which guides the tips of recording pipettes with micrometer precision to a microfluidic cell handling device. Using a patch pipette array mounted on a conventional micromanipulator, our automated patch clamp process mimics the original manual patch clamp as closely as possible, yet achieving a configuration where recordings are obtained from many patch electrodes in parallel. In addition, our implementation is extensible by design to allow the easy integration of specialized equipment such as ultrafast compound application tools. The resulting system offers fully automated patch clamp on purposely selected cells and combines high-quality gigaseal recordings with solution switching in the millisecond timescale.

  15. A novel post-processing scheme for two-dimensional electrical impedance tomography based on artificial neural networks.

    Directory of Open Access Journals (Sweden)

    Sébastien Martin

    Full Text Available Electrical Impedance Tomography (EIT is a powerful non-invasive technique for imaging applications. The goal is to estimate the electrical properties of living tissues by measuring the potential at the boundary of the domain. Being safe with respect to patient health, non-invasive, and having no known hazards, EIT is an attractive and promising technology. However, it suffers from a particular technical difficulty, which consists of solving a nonlinear inverse problem in real time. Several nonlinear approaches have been proposed as a replacement for the linear solver, but in practice very few are capable of stable, high-quality, and real-time EIT imaging because of their very low robustness to errors and inaccurate modeling, or because they require considerable computational effort.In this paper, a post-processing technique based on an artificial neural network (ANN is proposed to obtain a nonlinear solution to the inverse problem, starting from a linear solution. While common reconstruction methods based on ANNs estimate the solution directly from the measured data, the method proposed here enhances the solution obtained from a linear solver.Applying a linear reconstruction algorithm before applying an ANN reduces the effects of noise and modeling errors. Hence, this approach significantly reduces the error associated with solving 2D inverse problems using machine-learning-based algorithms.This work presents radical enhancements in the stability of nonlinear methods for biomedical EIT applications.

  16. Prediction of heat capacity of amine solutions using artificial neural network and thermodynamic models for CO2 capture processes

    Science.gov (United States)

    Afkhamipour, Morteza; Mofarahi, Masoud; Borhani, Tohid Nejad Ghaffar; Zanganeh, Masoud

    2018-03-01

    In this study, artificial neural network (ANN) and thermodynamic models were developed for prediction of the heat capacity ( C P ) of amine-based solvents. For ANN model, independent variables such as concentration, temperature, molecular weight and CO2 loading of amine were selected as the inputs of the model. The significance of the input variables of the ANN model on the C P values was investigated statistically by analyzing of correlation matrix. A thermodynamic model based on the Redlich-Kister equation was used to correlate the excess molar heat capacity ({C}_P^E) data as function of temperature. In addition, the effects of temperature and CO2 loading at different concentrations of conventional amines on the C P values were investigated. Both models were validated against experimental data and very good results were obtained between two mentioned models and experimental data of C P collected from various literatures. The AARD between ANN model results and experimental data of C P for 47 systems of amine-based solvents studied was 4.3%. For conventional amines, the AARD for ANN model and thermodynamic model in comparison with experimental data were 0.59% and 0.57%, respectively. The results showed that both ANN and Redlich-Kister models can be used as a practical tool for simulation and designing of CO2 removal processes by using amine solutions.

  17. Reducing blood loss during laparoscopic myomectomy by temporary uterine artery clamping using bulldog clamp

    Directory of Open Access Journals (Sweden)

    Kai-Jo Chiang

    2014-01-01

    Full Text Available Uterine myoma is the most common benign gynecologic tumor worldwide. Mini-invasive surgery has become popular for myomectomy, with advantages over laparotomy. However, reducing blood loss during laparoscopic myomectomy is a major concern for the surgeon because of the limitation in making a quick control bleeding during the operation. Several methods have proved to decrease blood flow, but are not always effective or available. We present a case of uterine myoma with the uterine arteries clamped by bulldog clamps during laparoscopic myomectomy. The myoma was removed successfully with minimal blood loss (<50 ml during the operation. This is an effective, safe, and reliable method for reducing bleeding during laparoscopic myomectomy that does not require ligation of the uterine artery.

  18. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path du...

  19. The problem of isotropic rectangular plate with four clamped edges

    Indian Academy of Sciences (India)

    uniformly distributed loads is a problem that has received considerable attention because of its technical importance. ... center deflection function of the fully clamped rectangular plate has three terms where the first one denotes ... An illustrative example is included of uniform load acting on a fully clamped rectangular plate.

  20. Off-clamp robotic partial nephrectomy: Technique and outcome.

    Science.gov (United States)

    Lamoshi, Abdulraouf Y; Salkini, Mohamad W

    2015-01-01

    Robotic partial nephrectomy (RPN) is a technically challenging procedure. Advanced skills are needed to accomplish tumor resection, hemostasis, and renorrhaphy within short ischemia time in RPN. Off-clamp RPN with zero ischemia may decrease the risk of ischemic reperfusion injury to the kidney. However, the off-clamp technique has been associated with an increased risk of blood loss. The purpose of this study was to evaluate the outcome of our modified off-clamp technique utilized in certain RPN cases. A total of 81 patients underwent RPN between September 2009 and July 2013 for renal masses. We studied a subgroup of patients who underwent off-clamp RPN with zero ischemia time. The off-clamp technique was utilized for exophytic, nonhilar tumors that have a base of 2 cm or less. We developed a novel technique to avoid ischemia reperfusion renal injury while minimizing blood loss in certain cases of RPN. Of the 81 cases of RPN, we reviewed and adopted the off-clamp technique in 34 patients (41.98%). Utilizing off-clamp RPN resulted in an average blood loss of 96.29 ml and 1.56 days (range: 1-3 days) of hospital stay and minimal change in serum creatinine. Off-clamp RPN is safe and feasible approach to excise certain kidney tumors. It carries the benefits of RPN and prevents ischemia reperfusion renal injury.

  1. Advanced patch-clamp techniques and single-channel analysis

    NARCIS (Netherlands)

    Biskup, B; Elzenga, JTM; Homann, U; Thiel, G; Wissing, F; Maathuis, FJM

    Much of our knowledge of ion-transport mechanisms in plant cell membranes comes from experiments using voltage-clamp. This technique allows the measurement of ionic currents across the membrane, whilst the voltage is held under experimental control. The patch-clamp technique was developed to study

  2. Studying mechanosensitive ion channels with an automated patch clamp

    NARCIS (Netherlands)

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Kocer, Armagan

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they

  3. Laparoscopic off-clamp partial nephrectomy using soft coagulation.

    Science.gov (United States)

    Hongo, Fumiya; Kawauchi, Akihiro; Ueda, Takashi; Fujihara-Iwata, Atsuko; Nakamura, Terukazu; Naya, Yoshio; Kamoi, Kazumi; Okihara, Koji; Miki, Tsuneharu

    2015-08-01

    To assess the effectiveness of soft coagulation in off-clamp laparoscopic partial nephrectomy. A total of 32 patients with renal tumors underwent laparoscopic partial nephrectomy with off-clamp using soft coagulation between May 2012 and September 2013. Tumor resection was carried out using a combination of bipolar forceps and a ball electrode using the soft coagulation system without hilar clamping. The outcomes of these patients were compared with those of 30 patients treated with hilar clamping. This off-clamp procedure was successfully completed in 31 cases. No significant differences were observed in the mean age (60 vs 61 years), sex (male/female; 25/7 vs 20/10), mean RENAL nephrometry score (5.7 vs 5.8), mean body mass index (24.4 vs 23) or tumor size (15 mm vs 16 mm) between the two groups. No significant differences were noted in positive surgical margins (0 vs 0) or blood loss (104 vs 115 cc) as well. In contrast, a significant difference was noted in the total operative time (278 vs 238 min). Serum creatinine percentage changes at 3 months were 6.4 versus 7.3% in the off-clamp and hilum-clamp groups, respectively, which were not significantly different. Off-clamp laparoscopic partial nephrectomy can be safely carried out by using a soft coagulation technique. © 2015 The Japanese Urological Association.

  4. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path...

  5. Inteligência Artificial: uma aplicação em uma indústria de processo contínuo Artificial Intelligence: an application in a continuous process industry

    Directory of Open Access Journals (Sweden)

    Miguel Afonso Sellitto

    2002-12-01

    Full Text Available Este trabalho descreve uma aplicação da lógica fuzzy de controle e do CBR (Raciocínio Baseado em Casos na indústria de processo contínuo. Essas técnicas são discutidas dentro do campo de conhecimentos da Inteligência Artificial, associadas ao processo de tomada de decisões empresariais. A Inteligência Artificial é apontada como um campo de conhecimentos que pode apoiar a tomada de decisões de um modo mais simples e mais preciso do que outros métodos, tais como a modelagem e a gestão por indicadores. As etapas para a construção de um sistema especialista, construído principalmente a partir de experiências empíricas humanas, também são discutidas. O trabalho se encerra apresentando uma rotina de tomada de decisão em um processo termoquímico na indústria cimenteira conduzida por um sistema especialista baseado em CBR e lógica fuzzy, e uma discussão sobre resultados comparados com operadores humanos nas mesmas condições.This paper describes an application of the fuzzy logic control and CBR in the continuous process industry. The techniques are discussed inside the larger branch of knowledge called Artificial Intelligence (AI, which can be related with the decision-making process in companies. Artificial Intelligence is pinpointed as a science that can support decisions in an easier and more precisely way than others methods as models and process indicators management. The steps for the erection of an Expert System, built mainly from human empirical experiences, are also discussed. The paper comes to an end by presenting a decision-making routine in a thermochemical process, in the cement industry, as performed by an Expert System decision-maker, based in CBR and fuzzy logic, and leading to a discussion about results and performance gains, in comparison with human-guided action in the same process.

  6. Scheduling the blended solution as industrial CO2 absorber in separation process by back-propagation artificial neural networks.

    Science.gov (United States)

    Abdollahi, Yadollah; Sairi, Nor Asrina; Said, Suhana Binti Mohd; Abouzari-lotf, Ebrahim; Zakaria, Azmi; Sabri, Mohd Faizul Bin Mohd; Islam, Aminul; Alias, Yatimah

    2015-11-05

    It is believe that 80% industrial of carbon dioxide can be controlled by separation and storage technologies which use the blended ionic liquids absorber. Among the blended absorbers, the mixture of water, N-methyldiethanolamine (MDEA) and guanidinium trifluoromethane sulfonate (gua) has presented the superior stripping qualities. However, the blended solution has illustrated high viscosity that affects the cost of separation process. In this work, the blended fabrication was scheduled with is the process arranging, controlling and optimizing. Therefore, the blend's components and operating temperature were modeled and optimized as input effective variables to minimize its viscosity as the final output by using back-propagation artificial neural network (ANN). The modeling was carried out by four mathematical algorithms with individual experimental design to obtain the optimum topology using root mean squared error (RMSE), R-squared (R(2)) and absolute average deviation (AAD). As a result, the final model (QP-4-8-1) with minimum RMSE and AAD as well as the highest R(2) was selected to navigate the fabrication of the blended solution. Therefore, the model was applied to obtain the optimum initial level of the input variables which were included temperature 303-323 K, x[gua], 0-0.033, x[MDAE], 0.3-0.4, and x[H2O], 0.7-1.0. Moreover, the model has obtained the relative importance ordered of the variables which included x[gua]>temperature>x[MDEA]>x[H2O]. Therefore, none of the variables was negligible in the fabrication. Furthermore, the model predicted the optimum points of the variables to minimize the viscosity which was validated by further experiments. The validated results confirmed the model schedulability. Accordingly, ANN succeeds to model the initial components of the blended solutions as absorber of CO2 capture in separation technologies that is able to industries scale up. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Unraveling the degradation of artificial amide bonds in nylon oligomer hydrolase: from induced-fit to acylation processes.

    Science.gov (United States)

    Baba, Takeshi; Boero, Mauro; Kamiya, Katsumasa; Ando, Hiroyuki; Negoro, Seiji; Nakano, Masayoshi; Shigeta, Yasuteru

    2015-02-14

    To elucidate how the nylon oligomer hydrolase (NylB) acquires its peculiar degradation activity towards non-biological amide bonds, we inspected the underlying enzymatic processes going from the induced-fit upon substrate binding to acylation. Specifically we investigated the mutational effects of two mutants, Y170F and D181G, indicated in former experiments as crucial systems because of their specific amino acid residues. Therefore, by adopting first-principles molecular dynamics complemented with metadynamics we provide a detailed insight into the underlying acylation mechanism. Our results show that while in the wild type (WT) the Tyr170 residue points the NH group towards the proton-acceptor site of an artificial amide bond, hence ready to react, in the Y170F this does not occur. The reason is ascribed to the absence of Tyr170 in the mutant, which is replaced by phenylalanine, which is unable to form hydrogen bond with the amide bond; thus, resulting in an increase in the activation barrier of more than 10 kcal mol(-1). Nonetheless, despite the lack of hydrogen bonding between the Y170F and the substrate, the highest free energy barrier for the induced-fit is similar to that of WT. This seems to suggest that in the induced-fit process, kinetics is little affected by the mutation. On the basis of additional structural homology analyses on the enzymes of the same family, we suggest that natural selection is responsible for the development of the peculiar hydrolytic activity of Arthrobacter sp. KI72.

  8. Reforging the Wedding Ring: Exploring a Semi-Artificial Model of Population for the United Kingdom with Gaussian process emulators

    Directory of Open Access Journals (Sweden)

    Viet Dung Cao

    2013-10-01

    Full Text Available Background: We extend the "Wedding Ring‟ agent-based model of marriage formation to include some empirical information on the natural population change for the United Kingdom together with behavioural explanations that drive the observed nuptiality trends. Objective: We propose a method to explore statistical properties of agent-based demographic models. By coupling rule-based explanations driving the agent-based model with observed data we wish to bring agent-based modelling and demographic analysis closer together. Methods: We present a Semi-Artificial Model of Population, which aims to bridge demographic micro-simulation and agent-based traditions. We then utilise a Gaussian process emulator - a statistical model of the base model - to analyse the impact of selected model parameters on two key model outputs: population size and share of married agents. A sensitivity analysis is attempted, aiming to assess the relative importance of different inputs. Results: The resulting multi-state model of population dynamics has enhanced predictive capacity as compared to the original specification of the Wedding Ring, but there are some trade-offs between the outputs considered. The sensitivity analysis allows identification of the most important parameters in the modelled marriage formation process. Conclusions: The proposed methods allow for generating coherent, multi-level agent-based scenarios aligned with some aspects of empirical demographic reality. Emulators permit a statistical analysis of their properties and help select plausible parameter values. Comments: Given non-linearities in agent-based models such as the Wedding Ring, and the presence of feedback loops, the uncertainty in the model may not be directly computable by using traditional statistical methods. The use of statistical emulators offers a way forward.

  9. Evaluation of clamp effects on LMFBR piping systems

    International Nuclear Information System (INIS)

    Jones, G.L.

    1980-01-01

    Loop-type liquid metal breeder reactor plants utilize thin-wall piping to mitigate through-wall thermal gradients due to rapid thermal transients. These piping loops require a support system to carry the combined weight of the pipe, coolant and insulation and to provide attachments for seismic restraints. The support system examined here utilizes an insulated pipe clamp designed to minimize the stresses induced in the piping. To determine the effect of these clamps on the pipe wall a non-linear, two-dimensional, finite element model of the clamp, insulation and pipe wall was used to determine the clamp/pipe interface load distributions which were then applied to a three-dimensional, finite element model of the pipe. The two-dimensional interaction model was also utilized to estimate the combined clamp/pipe stiffness

  10. Establishment of euglycemic clamp technique in beagle dogs

    International Nuclear Information System (INIS)

    Dong Lihou; Song Haifeng

    2010-01-01

    Objective: To establish a euglycemic clamp technique in beagle dogs. Methods: The euglycemic clamp technique was applied in healthy beagle dogs and the blood glucose, insulin, C-peptide, insulin and glucagon were monitored during the clamp. Results: The blood glucose was controlled within the basal level. The coefficient of variation was less than 5% during the clamp. The serum insulin concentration finally reached (40.0 ± 3.8) mIU/L stably and a significant inhibition was shown in endogenous insulin by the determination of C-peptide. But there was no significant increase in serum glucagon compared with basal values. Conclusion: Methodology confirmed that the euglycemic clamp technique is successful in beagle dogs and can be applied in the study of pharmacodynamics of insulin preparations. (authors)

  11. Replication Factor C Is a More Effective Proliferating Cell Nuclear Antigen (PCNA) Opener than the Checkpoint Clamp Loader, Rad24-RFC*

    Science.gov (United States)

    Thompson, Jennifer A.; Marzahn, Melissa R.; O'Donnell, Mike; Bloom, Linda B.

    2012-01-01

    Clamp loaders from all domains of life load clamps onto DNA. The clamp tethers DNA polymerases to DNA to increase the processivity of synthesis as well as the efficiency of replication. Here, we investigated proliferating cell nuclear antigen (PCNA) binding and opening by the Saccharomyces cerevisiae clamp loader, replication factor C (RFC), and the DNA damage checkpoint clamp loader, Rad24-RFC, using two separate fluorescence intensity-based assays. Analysis of PCNA opening by RFC revealed a two-step reaction in which RFC binds PCNA before opening PCNA rather than capturing clamps that have transiently and spontaneously opened in solution. The affinity of RFC for PCNA is about an order of magnitude lower in the absence of ATP than in its presence. The affinity of Rad24-RFC for PCNA in the presence of ATP is about an order magnitude weaker than that of RFC for PCNA, similar to the RFC-PCNA interaction in the absence of ATP. Importantly, fewer open clamp loader-clamp complexes are formed when PCNA is bound by Rad24-RFC than when bound by RFC. PMID:22115746

  12. Replication factor C is a more effective proliferating cell nuclear antigen (PCNA) opener than the checkpoint clamp loader, Rad24-RFC.

    Science.gov (United States)

    Thompson, Jennifer A; Marzahn, Melissa R; O'Donnell, Mike; Bloom, Linda B

    2012-01-13

    Clamp loaders from all domains of life load clamps onto DNA. The clamp tethers DNA polymerases to DNA to increase the processivity of synthesis as well as the efficiency of replication. Here, we investigated proliferating cell nuclear antigen (PCNA) binding and opening by the Saccharomyces cerevisiae clamp loader, replication factor C (RFC), and the DNA damage checkpoint clamp loader, Rad24-RFC, using two separate fluorescence intensity-based assays. Analysis of PCNA opening by RFC revealed a two-step reaction in which RFC binds PCNA before opening PCNA rather than capturing clamps that have transiently and spontaneously opened in solution. The affinity of RFC for PCNA is about an order of magnitude lower in the absence of ATP than in its presence. The affinity of Rad24-RFC for PCNA in the presence of ATP is about an order magnitude weaker than that of RFC for PCNA, similar to the RFC-PCNA interaction in the absence of ATP. Importantly, fewer open clamp loader-clamp complexes are formed when PCNA is bound by Rad24-RFC than when bound by RFC.

  13. Redes neurais artificiais aplicadas ao processo de coagulação Artificial neural networks applied to the coagulation process

    Directory of Open Access Journals (Sweden)

    Fábio Conceição de Menezes

    2009-12-01

    Full Text Available A coagulação é uma etapa de tratamento da água, e para tal são realizados ensaios de teste de jarro que permitem determinar a dose necessária dos agentes coagulante e químico de ajuste de pH no processo de coagulação. Contudo, esses ensaios demoram a ser executados, não respondendo em tempo real às mudanças da qualidade da água bruta. Para superar tal limitação, redes neurais artificiais multicamadas foram construídas (e seus pesos sinápticos ajustados, validadas e testadas para predizer a dosagem do hidróxido de sódio e do sulfato de alumínio - utilizados como agentes químico de ajuste de pH e coagulante, respectivamente. Os resultados dos modelos obtidos são compatíveis com os dados experimentais tendo em vista que as incertezas das estimativas estão na mesma ordem de grandeza das faixas indicadas pelos ensaios realizados de testes de jarro ao longo de quase seis anos.Coagulation is a stage in water treatment and, for this, jar tests are performed, which allows determining the optimal coagulant and alkalizer doses in coagulation process. However, these tests are time-consuming and do not enable real-time responses to changes in raw water quality. To overcome these limitations, artificial multilayer perceptron neural networks were built, trained, validated and tested to predict the aluminum and sodium hydroxide doses - used as coagulant and alkalizer, respectively. The results of these models are encouraging to consider that the estimated uncertainties have the same order of the variation limits magnitude indicated by the jar tests for almost a six-year period.

  14. Trends in Aortic Clamp Use During Coronary Artery Bypass Surgery: The Effect of Aortic Clamping Strategies on Neurologic Outcomes

    Science.gov (United States)

    Daniel, William T.; Kilgo, Patrick; Puskas, John D.; Thourani, Vinod H.; Lattouf, Omar M.; Guyton, Robert A.; Halkos, Michael E.

    2013-01-01

    Objective The purpose of this study was to determine the impact of different clamping strategies during CABG on the incidence of postoperative stroke. Methods In this case-control study, all patients at Emory hospitals from 2002–2009 with postoperative stroke after isolated CABG (N=141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (N=565). Patients were matched according to the Society of Thoracic Surgeons (STS) Predicted Risk of Postoperative Stroke (PROPS), which is based on 26 variables. On- (ONCAB) and off-pump (OPCAB) patients were matched separately. Multiple logistic regression analysis with adjusted odds ratios (OR) was performed to identify operative variables associated with postoperative stroke. Results Among the ONCAB cohort, the single cross-clamp technique was associated with a decreased risk of stroke compared to the double clamp (cross clamp + partial clamp) technique (OR=0.385, p=0.044). Within the OPCAB cohort, there was no significant difference in stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002–2009, clamp use decreased from 97.7% of cases to 72.7%. Conclusions During ONCAB, the use of a single cross-clamp compared to the double clamp technique decreases the risk of postoperative stroke. The use of any aortic clamp has decreased and epiaortic ultrasound use has increased from 2002–2009, indicating a change in operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta. PMID:23477689

  15. Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2017-05-01

    Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

  16. Crystal structure of the DNA polymerase III β subunit (β-clamp) from the extremophile Deinococcus radiodurans.

    Science.gov (United States)

    Niiranen, Laila; Lian, Kjersti; Johnson, Kenneth A; Moe, Elin

    2015-02-27

    Deinococcus radiodurans is an extremely radiation and desiccation resistant bacterium which can tolerate radiation doses up to 5,000 Grays without losing viability. We are studying the role of DNA repair and replication proteins for this unusual phenotype by a structural biology approach. The DNA polymerase III β subunit (β-clamp) acts as a sliding clamp on DNA, promoting the binding and processivity of many DNA-acting proteins, and here we report the crystal structure of D. radiodurans β-clamp (Drβ-clamp) at 2.0 Å resolution. The sequence verification process revealed that at the time of the study the gene encoding Drβ-clamp was wrongly annotated in the genome database, encoding a protein of 393 instead of 362 amino acids. The short protein was successfully expressed, purified and used for crystallisation purposes in complex with Cy5-labeled DNA. The structure, which was obtained from blue crystals, shows a typical ring-shaped bacterial β-clamp formed of two monomers, each with three domains of identical topology, but with no visible DNA in electron density. A visualisation of the electrostatic surface potential reveals a highly negatively charged outer surface while the inner surface and the dimer forming interface have a more even charge distribution. The structure of Drβ-clamp was determined to 2.0 Å resolution and shows an evenly distributed electrostatic surface charge on the DNA interacting side. We hypothesise that this charge distribution may facilitate efficient movement on encircled DNA and help ensure efficient DNA metabolism in D. radiodurans upon exposure to high doses of ionizing irradiation or desiccation.

  17. Infrared video patch-clamp technique for spiral ganglion neurons in rat cochlear slices.

    Science.gov (United States)

    Zha, Ding-Jun; Lin, Ying; Wang, Zhi-Ming; Lu, Lian-Jun; Xue, Tao; Gao, Xue; Li, Yun-Qing; Qiao, Li; Qiu, Jian-Hua

    2009-05-01

    Cochlear slice and infrared video patch-clamp techniques can be used in real-time observation. They provide a good method and platform for further study of the electrophysiological properties and auditory transduction mechanism of spiral ganglion neuron (SGN). To establish the isolated rat cochlear slice technique combined with the infrared video patch-clamp technique to explore the electrophysiological properties of the SGN. SD rats were divided into three groups according to postnatal days (0-2 days, 3-6 days and 7-14 days). After quickly making SD rat cochlear slices, the electrophysiological properties of the SGN were observed using the infrared differential interference contrast technique and patch-clamp recording, and the factors that affect the cochlear slice quality and patch-clamp recording were analysed. The successful slice rate was highest in 3-6-day-old SD rats and two to four slices could be prepared using each cochlea. It is crucial to maintain the connection of partial skull with the cochlea and the volute integrity when producing slices. The position of the cochlear axis and blade, and the slice preparation time were also important factors affecting slice quality and cell activity. SGN cells in good condition could easily be found using the infrared video patch-clamp technique to help the assessment of the seal test process. SGN resting membrane potential of whole-cell recording was -45.6+/-5.3 mV (n=52) and the currents of Na+ and K+ could be recorded.

  18. Using Artificial Soil and Dry-Column Flash Chromatography to Simulate Organic Substance Leaching Process: A Colorful Environmental Chemistry Experiment

    Science.gov (United States)

    de Avellar, Isa G. J.; Cotta, Tais A. P. G.; Neder, Amarilis de V. Finageiv

    2012-01-01

    Soil is an important and complex environmental compartment and soil contamination contributes to the pollution of aquifers and other water basins. A simple and low-cost experiment is described in which the mobility of three organic compounds in an artificial soil is examined using dry-column flash chromatography. The compounds were applied on top…

  19. Artificial Consciousness or Artificial Intelligence

    OpenAIRE

    Spanache Florin

    2017-01-01

    Artificial intelligence is a tool designed by people for the gratification of their own creative ego, so we can not confuse conscience with intelligence and not even intelligence in its human representation with conscience. They are all different concepts and they have different uses. Philosophically, there are differences between autonomous people and automatic artificial intelligence. This is the difference between intelligence and artificial intelligence, autonomous versus a...

  20. Planar patch-clamp force microscopy on living cells

    Energy Technology Data Exchange (ETDEWEB)

    Pamir, Evren [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany); George, Michael; Fertig, Niels [Nanion Technologies GmbH, Erzgiessereistr. 4, 80335 Munich (Germany); Benoit, Martin [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany)], E-mail: martin.benoit@physik.uni-muenchen.de

    2008-05-15

    Here we report a new combination of the patch-clamp technique with the atomic force microscope (AFM). A planar patch-clamp chip microstructured from borosilicate glass was used as a support for mechanical probing of living cells. The setup not only allows for immobilizing even a non-adherent cell for measurements of its mechanical properties, but also for simultaneously measuring the electrophysiological properties of a single cell. As a proof of principle experiment we measured the voltage-induced membrane movement of HEK293 and Jurkat cells in the whole-cell voltage clamp configuration. The results of these measurements are in good agreement with previous studies. By using the planar patch-clamp chip for immobilization, the AFM not only can image non-adhering cells, but also gets easily access to an electrophysiologically controlled cellular probe at low vibrational noise.

  1. Dynamic clamp: a powerful tool in cardiac electrophysiology

    NARCIS (Netherlands)

    Wilders, Ronald

    2006-01-01

    Dynamic clamp is a collection of closely related techniques that have been employed in cardiac electrophysiology to provide direct answers to numerous research questions regarding basic cellular mechanisms of action potential formation, action potential transfer and action potential synchronization

  2. Principles of artificial intelligence

    CERN Document Server

    Nilsson, Nils J

    1980-01-01

    A classic introduction to artificial intelligence intended to bridge the gap between theory and practice, Principles of Artificial Intelligence describes fundamental AI ideas that underlie applications such as natural language processing, automatic programming, robotics, machine vision, automatic theorem proving, and intelligent data retrieval. Rather than focusing on the subject matter of the applications, the book is organized around general computational concepts involving the kinds of data structures used, the types of operations performed on the data structures, and the properties of th

  3. Artificial intelligence in cardiology

    OpenAIRE

    Bonderman, Diana

    2017-01-01

    Summary Decision-making is complex in modern medicine and should ideally be based on available data, structured knowledge and proper interpretation in the context of an individual patient. Automated algorithms, also termed artificial intelligence that are able to extract meaningful patterns from data collections and build decisions upon identified patterns may be useful assistants in clinical decision-making processes. In this article, artificial intelligence-based studies in clinical cardiol...

  4. Voltage clamp methods for the study of membrane currents and SR Ca2+ release in adult skeletal muscle fibres

    Science.gov (United States)

    Hernández-Ochoa, Erick O.; Schneider, Martin F.

    2012-01-01

    Skeletal muscle excitation-contraction (E-C)1 coupling is a process composed of multiple sequential stages, by which an action potential triggers sarcoplasmic reticulum (SR)2 Ca2+ release and subsequent contractile activation. The various steps in the E-C coupling process in skeletal muscle can be studied using different techniques. The simultaneous recordings of sarcolemmal electrical signals and the accompanying elevation in myoplasmic Ca2+, due to depolarization-initiated SR Ca2+ release in skeletal muscle fibres, have been useful to obtain a better understanding of muscle function. In studying the origin and mechanism of voltage dependency of E-C coupling a variety of different techniques have been used to control the voltage in adult skeletal fibres. Pioneering work in muscles isolated from amphibians or crustaceans used microelectrodes or ‘high resistance gap’ techniques to manipulate the voltage in the muscle fibres. The development of the patch clamp technique and its variant, the whole-cell clamp configuration that facilitates the manipulation of the intracellular environment, allowed the use of the voltage clamp techniques in different cell types, including skeletal muscle fibres. The aim of this article is to present an historical perspective of the voltage clamp methods used to study skeletal muscle E-C coupling as well as to describe the current status of using the whole-cell patch clamp technique in studies in which the electrical and Ca2+ signalling properties of mouse skeletal muscle membranes are being investigated. PMID:22306655

  5. Force-controlled patch clamp of beating cardiac cells.

    Science.gov (United States)

    Ossola, Dario; Amarouch, Mohamed-Yassine; Behr, Pascal; Vörös, János; Abriel, Hugues; Zambelli, Tomaso

    2015-03-11

    From its invention in the 1970s, the patch clamp technique is the gold standard in electrophysiology research and drug screening because it is the only tool enabling accurate investigation of voltage-gated ion channels, which are responsible for action potentials. Because of its key role in drug screening, innovation efforts are being made to reduce its complexity toward more automated systems. While some of these new approaches are being adopted in pharmaceutical companies, conventional patch-clamp remains unmatched in fundamental research due to its versatility. Here, we merged the patch clamp and atomic force microscope (AFM) techniques, thus equipping the patch-clamp with the sensitive AFM force control. This was possible using the FluidFM, a force-controlled nanopipette based on microchanneled AFM cantilevers. First, the compatibility of the system with patch-clamp electronics and its ability to record the activity of voltage-gated ion channels in whole-cell configuration was demonstrated with sodium (NaV1.5) channels. Second, we showed the feasibility of simultaneous recording of membrane current and force development during contraction of isolated cardiomyocytes. Force feedback allowed for a gentle and stable contact between AFM tip and cell membrane enabling serial patch clamping and injection without apparent cell damage.

  6. Modelling methods in stress analysis of pipe coupling clamps

    International Nuclear Information System (INIS)

    Dutta, B.K.; Kushwaha, H.S.; Kakodkar, A.

    1987-01-01

    Pipe coupling using clamps are becoming more and more popular components in nuclear power plants and are used in place of conventional flanges because of their compactness, easy maintenance and more reliability. They are used in large numbers in Pressurised Heavy Water Reactors (PHWR) such as at the joint between feeder pipe and end-fitting, in F/M housing etc. Integrity of these clamps have direct effect on overall safety of the nuclear power plants. This necessitates proper design, fabrication, installation and maintenance of these components. Proper design of these clamps is a challenge to the designer. This is because of changing boundary conditions at the interface with the hub during various stages of loading. A detail stress analysis of clamps considering changing boundary conditions under various loadings can be done using finite element technique. In the following sections, two finite element modelling methods to simulate clamps along with hubs are described. Both these methods assumed absence of friction between the clamp and hubs during bolting, whereas absence of relative movement between them was assumed during other stages of loadings. (orig.)

  7. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  8. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    Science.gov (United States)

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  9. Clamp and clamp loader structures of the human checkpoint protein complexes, Rad9-1-1 and Rad17-RFC.

    Science.gov (United States)

    Shiomi, Yasushi; Shinozaki, Ayako; Nakada, Daisuke; Sugimoto, Katsunori; Usukura, Jiro; Obuse, Chikashi; Tsurimoto, Toshiki

    2002-08-01

    We have reported that protein imaging by transmission electron microscope observation based on low-angle platinum shadowing can reproduce characteristic ring structures of the replication clamp, proliferating cell nuclear antigen (PCNA), and the clamp loader protein, replication factor C (RFC). The checkpoint protein complexes, Rad9-Hus1-Rad1 (Rad9-1-1) and Rad17-RFCs2-5 (Rad17-RFC), have been predicted to function as novel clamp and clamp loader proteins, respectively, due to their amino acid sequence similarities with PCNA and RFC. We reconstituted human Rad9-1-1 and Rad17-RFC complexes in insect cells using a baculovirus expression system and showed purified Rad9-1-1 to be composed of equimolar amounts of Rad9, Hus1 and Rad1 proteins, exhibiting a native molecular mass of 100 kDa, in line with a trimeric complex. When Rad17 was co-expressed with the four small subunits of RFC in insect cells, these proteins formed a complex of 240 kDa that displayed DNA binding, ATPase activity and binding to its predicted target protein, Rad9-1-1. Analyses of the molecular architecture of Rad9-1-1 and Rad17-RFC using transmission electron microscopy, in comparison with PCNA and RFC, revealed the Rad9-1-1 complex to have a characteristic ring structure indistinguishable from that of PCNA in shape and size. In addition, the Rad17-RFC complex was found to be oval in structure and 26 x 22 nm in size with a cleft, reminiscent of the structure of RFC. Our direct comparison of images from the two sets of clamp and clamp loader proteins indicated that Rad9-1-1 and Rad17-RFC are, respectively, structural orthologs of PCNA and RFC, with presumed functions as novel clamp and clamp-loader proteins in eukaryotes.

  10. Artificial intelligence

    CERN Document Server

    Ennals, J R

    1987-01-01

    Artificial Intelligence: State of the Art Report is a two-part report consisting of the invited papers and the analysis. The editor first gives an introduction to the invited papers before presenting each paper and the analysis, and then concludes with the list of references related to the study. The invited papers explore the various aspects of artificial intelligence. The analysis part assesses the major advances in artificial intelligence and provides a balanced analysis of the state of the art in this field. The Bibliography compiles the most important published material on the subject of

  11. Product Development and Cost Analysis of Fabricating the Prototype of Roller Clamp in Intravenous (I.V) Tubing Medical Devices using Fused Deposition Modeling (FDM) Technology

    Science.gov (United States)

    Way, Yusoff

    2018-01-01

    The main aim of this research is to develop a new prototype and to conduct cost analysis of the existing roller clamp which is one of parts attached to Intravenous (I.V) Tubing used in Intravenous therapy medical device. Before proceed with the process to manufacture the final product using Fused Deposition Modeling (FDM) Technology, the data collected from survey were analyzed using Product Design Specifications approach. Selected concept has been proven to have better quality, functions and criteria compared to the existing roller clamp and the cost analysis of fabricating the roller clamp prototype was calculated.

  12. Artificial organ engineering

    CERN Document Server

    Annesini, Maria Cristina; Piemonte, Vincenzo; Turchetti, Luca

    2017-01-01

    Artificial organs may be considered as small-scale process plants, in which heat, mass and momentum transfer operations and, possibly, chemical transformations are carried out. This book proposes a novel analysis of artificial organs based on the typical bottom-up approach used in process engineering. Starting from a description of the fundamental physico-chemical phenomena involved in the process, the whole system is rebuilt as an interconnected ensemble of elemental unit operations. Each artificial organ is presented with a short introduction provided by expert clinicians. Devices commonly used in clinical practice are reviewed and their performance is assessed and compared by using a mathematical model based approach. Whilst mathematical modelling is a fundamental tool for quantitative descriptions of clinical devices, models are kept simple to remain focused on the essential features of each process. Postgraduate students and researchers in the field of chemical and biomedical engineering will find that t...

  13. A new clamp method for firing bricks | Obeng | Journal of Applied ...

    African Journals Online (AJOL)

    A new clamp method for firing bricks. ... Journal of Applied Science and Technology ... To overcome this operational deficiencies, a new method of firing bricks that uses brick clamp technique that incorporates a clamp wall of 60 cm thickness, a six tier approach of sealing the top of the clamp (by combination of green bricks) ...

  14. Dynamic clamp as a tool to study the functional effects of individual membrane currents

    NARCIS (Netherlands)

    Berecki, Géza; Verkerk, Arie O.; van Ginneken, Antoni C. G.; Wilders, Ronald

    2014-01-01

    Today, the patch-clamp technique is the main technique in electrophysiology to record action potentials or membrane current from isolated cells, using a patch pipette to gain electrical access to the cell. The common recording modes of the patch-clamp technique are current clamp and voltage clamp.

  15. Measuring beta-cell function relative to insulin sensitivity in youth: Does the hyperglycemic clamp suffice?

    Science.gov (United States)

    To compare beta-cell function relative to insulin sensitivity, disposition index (DI), calculated from two clamps (2cDI, insulin sensitivity from the hyperinsulinemic-euglycemic clamp and first-phase insulin from the hyperglycemic clamp) with the DI calculated from the hyperglycemic clamp alone (hcD...

  16. Intelligence: Real or artificial?

    Science.gov (United States)

    Schlinger, Henry D.

    1992-01-01

    Throughout the history of the artificial intelligence movement, researchers have strived to create computers that could simulate general human intelligence. This paper argues that workers in artificial intelligence have failed to achieve this goal because they adopted the wrong model of human behavior and intelligence, namely a cognitive essentialist model with origins in the traditional philosophies of natural intelligence. An analysis of the word “intelligence” suggests that it originally referred to behavior-environment relations and not to inferred internal structures and processes. It is concluded that if workers in artificial intelligence are to succeed in their general goal, then they must design machines that are adaptive, that is, that can learn. Thus, artificial intelligence researchers must discard their essentialist model of natural intelligence and adopt a selectionist model instead. Such a strategic change should lead them to the science of behavior analysis. PMID:22477051

  17. Artificial Reefs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An artificial reef is a human-made underwater structure, typically built to promote marine life in areas with a generally featureless bottom, control erosion, block...

  18. Artificial Metalloenzymes

    NARCIS (Netherlands)

    Rosati, Fiora; Roelfes, Gerard

    Artificial metalloenzymes have emerged as a promising approach to merge the attractive properties of homogeneous catalysis and biocatalysis. The activity and selectivity, including enantioselectivity, of natural metalloenzymes are due to the second coordination sphere interactions provided by the

  19. A dnaN Plasmid Shuffle Strain for Rapid In Vivo Analysis of Mutant Escherichia coli β Clamps Provides Insight Into the Role of Clamp in umuDC-Mediated Cold Sensitivity

    Science.gov (United States)

    Babu, Vignesh M. P.; Sutton, Mark D.

    2014-01-01

    The E. coli umuDC gene products participate in two temporally distinct roles: UmuD2C acts in a DNA damage checkpoint control, while UmuD'2C, also known as DNA polymerase V (Pol V), catalyzes replication past DNA lesions via a process termed translesion DNA synthesis. These different roles of the umuDC gene products are managed in part by the dnaN-encoded β sliding clamp protein. Co-overexpression of the β clamp and Pol V severely blocked E. coli growth at 30°C. We previously used a genetic assay that was independent of the ability of β clamp to support E. coli viability to isolate 8 mutant clamp proteins (βQ61K, βS107L, βD150N, βG157S, βV170M, βE202K, βM204K and βP363S) that failed to block growth at 30°C when co-overexpressed with Pol V. It was unknown whether these mutant clamps were capable of supporting E. coli viability and normal umuDC functions in vivo. The goals of this study were to answer these questions. To this end, we developed a novel dnaN plasmid shuffle assay. Using this assay, βD150N and βP363S were unable to support E. coli viability. The remaining 6 mutant clamps, each of which supported viability, were indistinguishable from β+ with respect to umuDC functions in vivo. In light of these findings, we analyzed phenotypes of strains overexpressing either β clamp or Pol V alone. The strain overexpressing β+, but not those expressing mutant β clamps, displayed slowed growth irrespective of the incubation temperature. Moreover, growth of the Pol V-expressing strain was modestly slowed at 30°, but not 42°C. Taken together, these results suggest the mutant clamps were identified due to their inability to slow growth rather than an inability to interact with Pol V. They further suggest that cold sensitivity is due, at least in part, to the combination of their individual effects on growth at 30°C. PMID:24896652

  20. Enhanced chromatin accessibility of the dosage compensated Drosophila male X-chromosome requires the CLAMP zinc finger protein.

    Science.gov (United States)

    Urban, Jennifer; Kuzu, Guray; Bowman, Sarah; Scruggs, Benjamin; Henriques, Telmo; Kingston, Robert; Adelman, Karen; Tolstorukov, Michael; Larschan, Erica

    2017-01-01

    The essential process of dosage compensation is required to equalize gene expression of X-chromosome genes between males (XY) and females (XX). In Drosophila, the conserved Male-specific lethal (MSL) histone acetyltransferase complex mediates dosage compensation by increasing transcript levels from genes on the single male X-chromosome approximately two-fold. Consistent with its increased levels of transcription, the male X-chromosome has enhanced chromatin accessibility, distinguishing it from the autosomes. Here, we demonstrate that the non-sex-specific CLAMP (Chromatin-linked adaptor for MSL proteins) zinc finger protein that recognizes GA-rich sequences genome-wide promotes the specialized chromatin environment on the male X-chromosome and can act over long genomic distances (~14 kb). Although MSL complex is required for increasing transcript levels of X-linked genes, it is not required for enhancing global male X-chromosome chromatin accessibility, and instead works cooperatively with CLAMP to facilitate an accessible chromatin configuration at its sites of highest occupancy. Furthermore, CLAMP regulates chromatin structure at strong MSL complex binding sites through promoting recruitment of the Nucleosome Remodeling Factor (NURF) complex. In contrast to the X-chromosome, CLAMP regulates chromatin and gene expression on autosomes through a distinct mechanism that does not involve NURF recruitment. Overall, our results support a model where synergy between a non-sex-specific transcription factor (CLAMP) and a sex-specific cofactor (MSL) creates a specialized chromatin domain on the male X-chromosome.

  1. Screening of E. coli β-clamp Inhibitors Revealed that Few Inhibit Helicobacter pylori More Effectively: Structural and Functional Characterization.

    Science.gov (United States)

    Pandey, Preeti; Verma, Vijay; Dhar, Suman Kumar; Gourinath, Samudrala

    2018-01-11

    The characteristic of interaction with various enzymes and processivity-promoting nature during DNA replication makes β-clamp an important drug target. Helicobacter pylori ( H. pylori ) have several unique features in DNA replication machinery that makes it different from other microorganisms. To find out whether difference in DNA replication proteins behavior accounts for any difference in drug response when compared to E. coli , in the present study, we have tested E. coli β-clamp inhibitor molecules against H. pylori β-clamp. Various approaches were used to test the binding of inhibitors to H. pylori β-clamp including docking, surface competition assay, complex structure determination, as well as antimicrobial assay. Out of five shortlisted inhibitor molecules on the basis of docking score, three molecules, 5-chloroisatin, carprofen, and 3,4-difluorobenzamide were co-crystallized with H. pylori β-clamp and the structures show that they bind at the protein-protein interaction site as expected. In vivo studies showed only two molecules, 5-chloroisatin, and 3,4-difluorobenzamide inhibited the growth of the pylori with MIC values in micro molar range, which is better than the inhibitory effect of the same drugs on E. coli . Therefore, the evaluation of such drugs against H. pylori may explore the possibility to use to generate species-specific pharmacophore for development of new drugs against H. pylori .

  2. Soil architecture relationships with dynamic soil physical processes: a conceptual study using natural, artificial, and 3D-printed soil cores

    Science.gov (United States)

    Lamandé, Mathieu; Schjønning, Per; Dal Ferro, Nicola; Morari, Francesco

    2017-04-01

    Pore system architecture is a key feature for understanding physical, biological and chemical processes in soils. Development of visualisation technics, especially x-ray CT, during recent years has been useful in describing the complex relationships between soil architecture and soil functions. We believe that combining visualization with physical models is a step further towards a better understanding of these relationships. We conducted a concept study using natural, artificial and 3D-printed soil cores. Eight natural soil cores (100 cm3) were sampled in a cultivated stagnic Luvisol at two depths (topsoil and subsoil), representing contrasting soil pore systems. Cylinders (100 cm3) were produced from plastic or from autoclaved aerated concrete. Holes of diameters 1.5 and 3 mm were drilled in the cylinder direction for the plastic cylinder and for one of the AAC cylinders. All natural and artificial cores were scanned in a micro x-ray CT scanner at a resolution of 35 µm. The reconstructed image of each soil core was printed with 3D multijet printing technology at a resolution of 29 µm. In some reconstructed digital volumes of the natural soil cores, pores of different sizes (equivalent diameter of 35, 70, 100, and 200 µm) were removed before additional 3D printing. Effective air-filled porosity, Darcian air permeability, and oxygen diffusion were measured on all natural, artificial and printed cores. The comparison of the natural and the artificial cores emphasized the difference in pore architecture between topsoil (sponge like) and subsoil (dominated by large vertical macropores). This study showed the high potential of using printed soil cores for understanding soil pore functions. The results confirm the suitability of the Ball model partitioning the pore system into arterial, marginal and remote pores to describe effects of soil structure on gas transport.

  3. Artificial sweeteners

    DEFF Research Database (Denmark)

    Raben, Anne Birgitte; Richelsen, Bjørn

    2012-01-01

    Artificial sweeteners can be a helpful tool to reduce energy intake and body weight and thereby risk for diabetes and cardiovascular diseases (CVD). Considering the prevailing diabesity (obesity and diabetes) epidemic, this can, therefore, be an important alternative to natural, calorie......-containing sweeteners. The purpose of this review is to summarize the current evidence on the effect of artificial sweeteners on body weight, appetite, and risk markers for diabetes and CVD in humans....

  4. Structure of the sliding clamp from the fungal pathogen Aspergillus fumigatus (AfumPCNA) and interactions with Human p21.

    Science.gov (United States)

    Marshall, Andrew C; Kroker, Alice J; Murray, Lauren A M; Gronthos, Kahlia; Rajapaksha, Harinda; Wegener, Kate L; Bruning, John B

    2017-03-01

    The fungal pathogen Aspergillus fumigatus has been implicated in a drastic increase in life-threatening infections over the past decade. However, compared to other microbial pathogens, little is known about the essential molecular processes of this organism. One such fundamental process is DNA replication. The protein responsible for ensuring processive DNA replication is PCNA (proliferating cell nuclear antigen, also known as the sliding clamp), which clamps the replicative polymerase to DNA. Here we present the first crystal structure of a sliding clamp from a pathogenic fungus (A. fumigatus), at 2.6Å. Surprisingly, the structure bears more similarity to the human sliding clamp than other available fungal sliding clamps. Reflecting this, fluorescence polarization experiments demonstrated that AfumPCNA interacts with the PCNA-interacting protein (PIP-box) motif of human p21 with an affinity (K d ) of 3.1 μm. Molecular dynamics simulations were carried out to better understand how AfumPCNA interacts with human p21. These simulations revealed that the PIP-box bound to AfuPCNA forms a secondary structure similar to that observed in the human complex, with a central 3 10 helix contacting the hydrophobic surface pocket of AfumPCNA as well as a β-strand that forms an antiparallel sheet with the AfumPCNA surface. Differences in the 3 10 helix interaction with PCNA, attributed to residue Thr131 of AfumPCNA, and a less stable β-strand formation, attributed to residues Gln123 and His125 of AfumPCNA, are likely causes of the over 10-fold lower affinity of the p21 PIP-box for AfumPCNA as compared to hPCNA. The atomic coordinates and structure factors for the Aspergillus fumigatus sliding clamp can be found in the RCSB Protein Data Bank (http://www.rcsb.org) under the accession code 5TUP. © 2017 Federation of European Biochemical Societies.

  5. Axially Modulated Clamped-Guided Arch Resonator for Memory and Logic Applications

    KAUST Repository

    Hafiz, Md Abdullah Al

    2017-11-03

    We experimentally demonstrate memory and logic devices based on an axially modulated clamped-guided arch resonator. The device are electrostatically actuated and capacitively sensed, while the resonance frequency modulation is achieved through an axial electrostatic force from the guided side of the clamped-guided arch microbeam. We present two case studies: first, a dynamic memory based on the nonlinear frequency response of the resonator, and second, a reprogrammable two-input logic gate based on the linear frequency modulation of the resonator. These devices show energy cost per memory/logic operation in pJ, are fully compatible with CMOS fabrication processes, have the potential for on-chip system integration, and operate at room temperature.

  6. A NOVEL SINGLE IMPEDANCE NETWORK BASED NEUTRAL POINT CLAMPED SEVEN LEVEL THREE PHASE INVETER WITH REDUCED CLAMPING DIODES FOR REGENERATIVE APPLICATIONS

    OpenAIRE

    T. A. Raghavendiran; C.L.Kuppuswamy

    2012-01-01

    A Multilevel Inverter (MLI) can eliminate the need for the step-up transformer and reduce the harmonics produced by the inverter. This paper presents Neutral Point Clamped (NPC) seven level inverter with less number of clamping diodes which is suitable for regenerative loads such as three phase induction motor with regenerative braking. To reduce the stress across the main switches, diodes are clamped anti-parallel to the main switches. In Earlier configurations, the numbers of clamping diode...

  7. CYCLOPS: A mobile robotic platform for testing and validating image processing and autonomous navigation algorithms in support of artificial vision prostheses.

    Science.gov (United States)

    Fink, Wolfgang; Tarbell, Mark A

    2009-12-01

    While artificial vision prostheses are quickly becoming a reality, actual testing time with visual prosthesis carriers is at a premium. Moreover, it is helpful to have a more realistic functional approximation of a blind subject. Instead of a normal subject with a healthy retina looking at a low-resolution (pixelated) image on a computer monitor or head-mounted display, a more realistic approximation is achieved by employing a subject-independent mobile robotic platform that uses a pixelated view as its sole visual input for navigation purposes. We introduce CYCLOPS: an AWD, remote controllable, mobile robotic platform that serves as a testbed for real-time image processing and autonomous navigation systems for the purpose of enhancing the visual experience afforded by visual prosthesis carriers. Complete with wireless Internet connectivity and a fully articulated digital camera with wireless video link, CYCLOPS supports both interactive tele-commanding via joystick, and autonomous self-commanding. Due to its onboard computing capabilities and extended battery life, CYCLOPS can perform complex and numerically intensive calculations, such as image processing and autonomous navigation algorithms, in addition to interfacing to additional sensors. Its Internet connectivity renders CYCLOPS a worldwide accessible testbed for researchers in the field of artificial vision systems. CYCLOPS enables subject-independent evaluation and validation of image processing and autonomous navigation systems with respect to the utility and efficiency of supporting and enhancing visual prostheses, while potentially reducing to a necessary minimum the need for valuable testing time with actual visual prosthesis carriers.

  8. Crystal structure of an archaeal DNA sliding clamp: proliferating cell nuclear antigen from Pyrococcus furiosus.

    Science.gov (United States)

    Matsumiya, S; Ishino, Y; Morikawa, K

    2001-01-01

    The proliferating cell nuclear antigen (PCNA) is now recognized as one of the key proteins in DNA metabolic events because of its direct interactions with many proteins involved in important cellular processes. We have determined the crystal structure of PCNA from a hyperthermophilic archaeon, Pyrococcus furiosus (pfuPCNA), at 2.1 A resolution. pfuPCNA forms a toroidal, ring-shaped structure consisting of homotrimeric molecules, which is also observed in the PCNA crystals from human and yeast. The overall structure of pfuPCNA is highly conserved with other PCNA proteins, as well as with the bacterial ss clamp and the bacteriophage gp45. This result shows that the three-dimensional structure of the sliding clamp is conserved in the three domains of life. pfuPCNA has two remarkable features compared with the human and yeast PCNA molecules: it has more ion pairs and fewer intermolecular main chain hydrogen bonds. The former may contribute to the thermal stability of pfuPCNA, and the latter may be the cause of the stimulatory effect of pfuPCNA on the DNA synthesizing activity of P. furiosus DNA polymerases in the absence of the clamp loader replication factor C in vitro.

  9. New active load voltage clamp for HF-link converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, M.A.E.

    2005-07-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core. (au)

  10. A new configuration for multilevel converters with diode clamped topology

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.

    2008-01-01

    Due to the increased use of renewable energy and power elctronic applications, more multilevel converters (MLC) are developed. A Neutral Point Clamped (NPC) inverter is one of the most used multilevel topologies for wind turbine (WT) and photovoltaic (PV) applications. One of the most crucial...... points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless...

  11. Improved DNA clamps by stacking to adjacent nucleobases

    DEFF Research Database (Denmark)

    Fatthalla, M.I.; Pedersen, Erik Bjerregaard

    2012-01-01

    Three or four aromatic rings interconnected by acetylene bridges form a stiff conjugated system with sufficient conformational freedom to make it useful to link together the two strands of a DNA clamp. Upon targeting a ssDNA, the conformational flexibility allows better stacking of the linker...... to the underlying non-planar base triplet in the formed triplex. This type of triplexes has a substantially higher thermal melting temperature which can be further improved by inserting locked nucleic acids (LNAs) in the Hoogsteen part of the clamp. An extremely high sensitivity to mismatches is observed...

  12. Artificial intelligence

    International Nuclear Information System (INIS)

    Perret-Galix, D.

    1992-01-01

    A vivid example of the growing need for frontier physics experiments to make use of frontier technology is in the field of artificial intelligence and related themes. This was reflected in the second international workshop on 'Software Engineering, Artificial Intelligence and Expert Systems in High Energy and Nuclear Physics' which took place from 13-18 January at France Telecom's Agelonde site at La Londe des Maures, Provence. It was the second in a series, the first having been held at Lyon in 1990

  13. Artificial Intelligence

    CERN Document Server

    Warwick, Kevin

    2011-01-01

    if AI is outside your field, or you know something of the subject and would like to know more then Artificial Intelligence: The Basics is a brilliant primer.' - Nick Smith, Engineering and Technology Magazine November 2011 Artificial Intelligence: The Basics is a concise and cutting-edge introduction to the fast moving world of AI. The author Kevin Warwick, a pioneer in the field, examines issues of what it means to be man or machine and looks at advances in robotics which have blurred the boundaries. Topics covered include: how intelligence can be defined whether machines can 'think' sensory

  14. Impact of Individual Proliferating Cell Nuclear Antigen-DNA Contacts on Clamp Loading and Function on DNA*

    Science.gov (United States)

    Zhou, Yayan; Hingorani, Manju M.

    2012-01-01

    Ring-shaped clamp proteins encircle DNA and affect the work of many proteins, notably processive replication by DNA polymerases. Crystal structures of clamps show several cationic residues inside the ring, and in a co-crystal of Escherichia coli β clamp-DNA, they directly contact the tilted duplex passing through (Georgescu, R. E., Kim, S. S., Yurieva, O., Kuriyan, J., Kong, X. P., and O'Donnell, M. (2008) Structure of a sliding clamp on DNA. Cell 132, 43–54). To investigate the role of these contacts in reactions involving circular clamps, we examined single arginine/lysine mutants of Saccharomyces cerevisiae proliferating cell nuclear antigen (PCNA) in replication factor C (RFC)-catalyzed loading of the clamp onto primer template DNA (ptDNA). Previous kinetic analysis has shown that ptDNA entry inside an ATP-activated RFC-PCNA complex accelerates clamp opening and ATP hydrolysis, which is followed by slow PCNA closure around DNA and product dissociation. Here we directly measured multiple steps in the reaction (PCNA opening, ptDNA binding, PCNA closure, phosphate release, and complex dissociation) to determine whether mutation of PCNA residues Arg-14, Lys-20, Arg-80, Lys-146, Arg-149, or Lys-217 to alanine affects the reaction mechanism. Contrary to earlier steady state analysis of these mutants (McNally, R., Bowman, G. D., Goedken, E. R., O'Donnell, M., and Kuriyan, J. (2010) Analysis of the role of PCNA-DNA contacts during clamp loading. BMC Struct. Biol. 10, 3), our pre-steady state data show that loss of single cationic residues can alter the rates of all DNA-linked steps in the reaction, as well as movement of PCNA on DNA. These results explain an earlier finding that individual arginines and lysines inside human PCNA are essential for polymerase δ processivity (Fukuda, K., Morioka, H., Imajou, S., Ikeda, S., Ohtsuka, E., and Tsurimoto, T. (1995) Structure-function relationship of the eukaryotic DNA replication factor, proliferating cell nuclear antigen

  15. [Artificial neural networks in Neurosciences].

    Science.gov (United States)

    Porras Chavarino, Carmen; Salinas Martínez de Lecea, José María

    2011-11-01

    This article shows that artificial neural networks are used for confirming the relationships between physiological and cognitive changes. Specifically, we explore the influence of a decrease of neurotransmitters on the behaviour of old people in recognition tasks. This artificial neural network recognizes learned patterns. When we change the threshold of activation in some units, the artificial neural network simulates the experimental results of old people in recognition tasks. However, the main contributions of this paper are the design of an artificial neural network and its operation inspired by the nervous system and the way the inputs are coded and the process of orthogonalization of patterns.

  16. Benthic processes on and around artificial structures in Swedish coastal waters; Bentiska processer paa och runt artificiella strukturer i Sveriges kustvatten

    Energy Technology Data Exchange (ETDEWEB)

    Malm, Torleif (Stockholms Universitet, Stockholms marina forskningscentrum (Sweden)); Engkvist, Roland (Linneuniversitetet, Institutionen foer Naturvetenskap, Vaexjoe (Sweden))

    2011-03-15

    stones in the scour protection quickly. The artificial and natural substrates had a similar community structure after two years. In contrast it seems like the bottom has been affected by the farm throughout the area. Compared with previous years, the natural substrates in 2009 had a larger biomass of mussels and barnacles and a lower biomass of filamentous algae. The differences, however, were small. The conclusion of this study is that wind power farms may potentially cause ecological effects in the benthic communities but as our study lack geographical and temporal extension, this conclusion is weak. As the abiotic conditions around our coasts shift, it is impossible to draw firm conclusions from one site. It is also difficult to draw conclusions from the short period after the construction of the farm. Meteorological and oceanographic processes not related to the wind farm may have contributed to the result

  17. Initial results of selective renal parenchymal clamping with an adjustable kidney clamp in nephron-sparing surgery: an easy way to minimise renal ischaemia.

    Science.gov (United States)

    Cheng, K C; Yiu, M K; Ho, S H; Ng, T L; Tsu, H L; Ma, W K

    2016-12-01

    A renal parenchymal clamp has been used at our centre since March 2012. It is used in position over the kidney to achieve optimal vascular control of a tumour while minimising parenchymal ischaemia. This study aimed to report the feasibility, surgical outcome, and oncological control of a kidney clamp in partial nephrectomy. This study was conducted at a teaching hospital in Hong Kong. Partial nephrectomies performed from January 2009 to March 2015 were reviewed. The tumour characteristics and surgical outcomes of kidney clamp were studied and compared with traditional hilar clamping. A total of 92 patients were identified during the study period. Kidney clamps were used in 20 patients and hilar clamping in 72, with a mean follow-up of 27 and 37 months, respectively. For patients in whom a kidney clamp was applied, all tumours were exophytic to a different extent and the majority (90%) were located at the polar region. The PADUA (preoperative aspects and dimensions used for an anatomical) classification nephrometry score was also lower than those in whom hilar clamping was used (7.07 vs 8.34; P=0.002). The clamp was used in open, laparoscopic, and robot-assisted surgery. Operating time was shorter (207 ± 72 mins vs 306 ± 80 mins; Pkidney clamp. No acute kidney injury occurred. Postoperative renal function was comparable between the two groups. Partial nephrectomy using parenchymal clamping is safe and feasible in selected cases. The postoperative renal function and oncological control were satisfactory.

  18. In Pursuit of Artificial Intelligence.

    Science.gov (United States)

    Watstein, Sarah; Kesselman, Martin

    1986-01-01

    Defines artificial intelligence and reviews current research in natural language processing, expert systems, and robotics and sensory systems. Discussion covers current commercial applications of artificial intelligence and projections of uses and limitations in library technical and public services, e.g., in cataloging and online information and…

  19. Artificial Ligaments: Promise or Panacea?

    Science.gov (United States)

    Lubell, Adele

    1987-01-01

    The Food and Drug Administration has approved a prosthetic ligament for limited use in persons with damaged anterior cruciate ligaments (ACL). This article addresses ligament repair, ACL tears, current treatment, development of the Gore-Tex artificial ligament, other artificial ligaments in process, and arguments for and against their use.…

  20. Artificial Intelligence and Language Comprehension.

    Science.gov (United States)

    National Inst. of Education (DHEW), Washington, DC. Basic Skills Group. Learning Div.

    The three papers in this volume concerning artificial intelligence and language comprehension were commissioned by the National Institute of Education to further the understanding of the cognitive processes that enable people to comprehend what they read. The first paper, "Artificial Intelligence and Language Comprehension," by Terry Winograd,…

  1. Management of Senile Ptosis with Levator Muscle Resection Using the Putterman Clamp

    Science.gov (United States)

    2016-01-01

    Summary: Putterman clamp, a muscle clamp, is commonly used in conjunctival müllerectomies. We report 3 cases of senile ptosis repaired with levator muscle resection using the Putterman clamp. The redundant levator aponeurosis was removed with electrocautery after clamping with the Putterman clamp. The levator muscle was refixed to the tarsus with three 4-0 Vicryl stitches after adjusting the height of the eyelid fissure. No intraoperative difficulties were encountered. Ecchymosis and edema were limited in the immediate postoperative period. No complications were noted during the follow-up. The benefits of using the Putterman clamp in levator muscle resection are illustrated in these cases. PMID:27482474

  2. Artificial Intelligence and CALL.

    Science.gov (United States)

    Underwood, John H.

    The potential application of artificial intelligence (AI) to computer-assisted language learning (CALL) is explored. Two areas of AI that hold particular interest to those who deal with language meaning--knowledge representation and expert systems, and natural-language processing--are described and examples of each are presented. AI contribution…

  3. Artificial organs: recent progress in artificial hearing and vision.

    Science.gov (United States)

    Ifukube, Tohru

    2009-01-01

    Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas.

  4. A piezoelectric vibration harvester based on clamped-guided beams

    NARCIS (Netherlands)

    Wang, Z.; Matova, S.; Elfrink, R.; Jambunathan, M.; Nooijer, C. de; Schaijk, R. van; Vullers, R.J.M.

    2012-01-01

    The paper addresses the design, modeling, fabrication and experimental results of a piezoelectric energy harvester based on clamped-guided beams. The design is featured by shorter mass displacement and higher reliability than cantilever beams. Two separate sets of capacitors allow exploiting both

  5. Pulsewidth-modulated 2-source neutral-point-clamped inverter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chang; Gao, Feng

    2007-01-01

    This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X-...

  6. analytical bending solution of all clamped isotropic rectangular plate

    African Journals Online (AJOL)

    HP

    is the plate flexural rigidity, is the Young's modulus of elasticity of the plate, is the uniformly distributed load, is the deflection, is the modulus of subgrade reaction, is the thickness of the plate and is the. Poisson's ratio of the plate. The independent co-ordinates, x and y, of the clamped plate can be expressed in the form of ...

  7. Beyond the patch clamp: nanotechnologies for intracellular recording.

    Science.gov (United States)

    Kruskal, Peter B; Jiang, Zhe; Gao, Teng; Lieber, Charles M

    2015-04-08

    The patch clamp is a fundamental tool for neuroscientists, offering insights that have shaped our understanding of the brain. Advances in nanotechnology suggest that the next generation of recording methods is now within reach. We discuss the complexity and future promise of applying nanoscience to neural recording. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. INOVASI SAMBUNGAN MEKANIS MENGGUNAKAN CLAMP BAJA UNTUK TULANGAN BETON

    Directory of Open Access Journals (Sweden)

    Parmo

    2015-12-01

    Full Text Available In the last few years, Indonesian urban growth has tends to be lead to the overground space. This was caused by the significant population increasement the lackness of land availability. The phenomenon is also marked with the increasing number of high-rise buildings and skyscrapers. However, high-rise buildings and skyscrapers have the potential dangers against earthquakes, even more Indonesia lay on an earthquake-prone areas. There are two main things that need to be considered in the planning of earthquake-resistant buildings, which is strength and ductility. Deformation capability and the connection strength between the reinforcement taken into consideration in the design of earthquake-resistant structures. From the steel clamp tensile test results for D13’s mechanical connection reinforcement, it gained 270.69 Mpa for yield strength, 351.45 MPa for ultimate tensile strength and 4757 kg for maximum load with 40% elongation. As for the D16’s mechanical connection reinforcement gained 217.80 MPa for yield strength, 327 605 MPa for ultimate tensile strength and 6717 kg for maximum load with 32% elongation. This study uses two pieces of steel clamp, but in order to obtain a better result then it need to be add more clamps while increasing the steel clamp material quality.

  9. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.

    2012-01-01

    for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...

  10. Pulsewidth Modulation of Neutral-Point-Clamped Indirect Matrix Converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Poh Chiang, Loh; Gao, Feng

    2008-01-01

    discussed in the existing literature. Addressing the previously described issues, this paper focuses on the operational mode analysis of a three-level indirect matrix converter implemented using a neutral-point-clamped inversion stage and the design of a number of PWM and modulation ratio compensation...

  11. Euglycemic clamp insulin sensitivity and longitudinal systolic blood pressure

    DEFF Research Database (Denmark)

    Petrie, John R; Malik, Muhammad Omar; Balkau, Beverley

    2013-01-01

    and Cardiovascular disease (RISC) study, we measured insulin sensitivity (M/I) using the euglycemic clamp technique in 1073 healthy European adults (587 women, 486 men) aged 30 to 60 years followed up 3 years later. Systolic BP (SBP) at baseline was higher in insulin-resistant women (ie, those in the low sex...

  12. Five-level Z-source diode-clamped inverter

    DEFF Research Database (Denmark)

    Gao, F.; Loh, Poh Chiang; Blaabjerg, Frede

    2010-01-01

    This study proposes a five-level Z-source diode-clamped inverter designed with two intermediate Z-source networks connected between the dc input sources and rear-end inverter circuitry. By partially shorting the Z-source networks, new operating states not previously reported for two-level Z...

  13. Artificial intelligence in cardiology.

    Science.gov (United States)

    Bonderman, Diana

    2017-12-01

    Decision-making is complex in modern medicine and should ideally be based on available data, structured knowledge and proper interpretation in the context of an individual patient. Automated algorithms, also termed artificial intelligence that are able to extract meaningful patterns from data collections and build decisions upon identified patterns may be useful assistants in clinical decision-making processes. In this article, artificial intelligence-based studies in clinical cardiology are reviewed. The text also touches on the ethical issues and speculates on the future roles of automated algorithms versus clinicians in cardiology and medicine in general.

  14. Hyperinsulinemic Euglycemic Clamp for cardiac PET: An Initial Experience

    International Nuclear Information System (INIS)

    Agrawal, Saumya; Salgia, Ritu; Baikerikar, Sushanti; Khandare, Hemant; Lele, Vikram

    2007-01-01

    Full text: Aim: To study the adequacy of hyperinsulinemic euglycemic clamp to yield technically adequate and clinically meaningful cardiac scans in diabetic patients. 18 F- FDG scans are of suboptimal quality as high level of glucose competes with flurodeoxyglucose for cardiac uptake. Thus to allow quick stabilization of metabolic environment and to get superior quality images, insulin clamp is an accepted technique. Methods: 8 patients (7 males and 1 female) of ages ranging from 43 to 69 years were evaluated in this ongoing study, referred for estimation of myocardial viability post myocardial infarction. All patients were required 6 hours fasting. Initially they were injected with 20 milicurie of Technetium Tetrofosmin and myocardial perfusion imaging done 1 hour later on GE dual head gamma camera. Blood glucose levels were checked. Their blood sugars were in the range of 130mg% - 170mg%. Insulin clamp was applied depending upon the glucose level obtained, according to ASNC guidelines for PET Myocardial Glucose Metabolism and Perfusion Imaging. On stabilization of blood glucose levels, 10 milicurie of 18 F- FDG was injected. Imaging was done 1 hour later on Dedicated 16 slice STE PET CT scanner. There was no incidence of hypoglycemia or any other side effects during the procedure. Entire procedure including tetrofosmin imaging took approximately 4 hours. Results: Good quality images were obtained after the use of insulin clamp. Conclusion: Infusion of insulin and glucose gives stable plasma glucose and serum insulin levels during imaging. The insulin clamp technique makes it possible to adjust and maintain a metabolic steady state during PET study. It does not alter 18F-FDG uptake patterns in different myocardial areas. It permits the use of smaller FDG doses for the patient and gives superior quality images. The technique is safe and should improve both the clinical use and cost effectiveness of FDG-PET imaging for identification of injured but viable myocardium

  15. Impact of Early Release of the IVC Clamp from Different IVC Clamping Maneuvers on Changes in Hemodynamic Parameters in Living Donor Liver Transplantation.

    Science.gov (United States)

    Shih, Tsung-Hsiao; Huang, Chia-Jung; Chen, Chao-Long; Cheng, Kwok-Wai; Wu, Shao-Chun; Yang, Sheng-Chun; Juang, Sin-Ei; Lee, Ying-En; Jawan, Bruno; Wang, Chih-Hsien

    2015-09-06

    BACKGROUND The aim of this study was to evaluate the impact of different methods of inferior vena cava (IVC) clamping and release of the cross clamp on hemodynamic parameters of recipients during living donor liver transplantation. MATERIAL AND METHODS Ninety-six adult living donor liver transplantation patients were divided into 3 groups according to cross-clamp of the IVC for all the hepatic vein and portal vein reconstruction (G1), cross-clamp of the IVC only for hepatic vein reconstruction (G2), and side-clamp of the IVC for hepatic vein reconstruction (G3). In G2 and G2, the reconstructed hepatic vein was clamped instead of the IVC for portal vein reconstruction. The hemodynamic parameters among groups were compared by 1-way ANOVA and the complications in each group were compared using the Kruskal-Wallis test. RESULTS Changes in percentage of MAP and CO in G3 were significantly less than that of G1 and G2 for hepatic vein reconstruction. Hemodynamic parameters of G2 and G3 normalized to pre-clamped values during portal vein reconstruction, while the hemodynamics of G1 remained unstable. CONCLUSIONS Hemodynamic changes were less pronounced in LT with side-clamp of the inferior cava vein versus total cross-clamp. Early release of the IVC clamp minimized the hemodynamic changes. There were no differences in terms of outcome (morbidity and mortality).

  16. Artificial Intelligence.

    Science.gov (United States)

    Lawrence, David R; Palacios-González, César; Harris, John

    2016-04-01

    It seems natural to think that the same prudential and ethical reasons for mutual respect and tolerance that one has vis-à-vis other human persons would hold toward newly encountered paradigmatic but nonhuman biological persons. One also tends to think that they would have similar reasons for treating we humans as creatures that count morally in our own right. This line of thought transcends biological boundaries-namely, with regard to artificially (super)intelligent persons-but is this a safe assumption? The issue concerns ultimate moral significance: the significance possessed by human persons, persons from other planets, and hypothetical nonorganic persons in the form of artificial intelligence (AI). This article investigates why our possible relations to AI persons could be more complicated than they first might appear, given that they might possess a radically different nature to us, to the point that civilized or peaceful coexistence in a determinate geographical space could be impossible to achieve.

  17. Artificial intelligence

    OpenAIRE

    Duda, Antonín

    2009-01-01

    Abstract : Issue of this work is to acquaint the reader with the history of artificial inteligence, esspecialy branch of chess computing. Main attention is given to progress from fifties to the present. The work also deals with fighting chess programs against each other, and against human opponents. The greatest attention is focused on 1997 and duel Garry Kasparov against chess program Deep Blue. The work is divided into chapters according to chronological order.

  18. Artificial Wormhole

    OpenAIRE

    Kirillov, A. A.; Savelova, E. P.

    2012-01-01

    It is shown that recently reported result by the OPERA Collaboration (arXive:1109.4897) of an early arrival time of muon neutrinos with respect to the speed of light in vacuum does not violate standard physical laws. We show that vacuum polarization effects in intensive external fields may form a wormhole-like object. The simplest theory of such an effect is presented and basic principles of formation of an artificial wormhole are also considered.

  19. Active energy recovery clamping circuit to improve the performance of power converters

    Science.gov (United States)

    Whitaker, Bret; Barkley, Adam

    2017-05-09

    A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

  20. Targeting the β-clamp in Helicobacter pylori with FDA-approved drugs reveals micromolar inhibition by diflunisal.

    Science.gov (United States)

    Pandey, Preeti; Verma, Vijay; Gautam, Gunjan; Kumari, Nilima; Dhar, Suman Kumar; Gourinath, Samudrala

    2017-08-01

    The β-clamp is the processivity-promoting factor for most of the enzymes in prokaryotic DNA replication; hence, it is a crucial drug target. In the present study, we investigated the β-clamp from Helicobacter pylori, aiming to seek potential drug molecules against this gastric-cancer-causing bacterium. An in silico screening of Food and Drug Administration (FDA) approved drugs against the H. pylori β-clamp, followed by its in vitro inhibition using a surface competition approach, yielded the drug diflunisal as a positive initial hit. Diflunisal inhibits the growth of H. pylori in the micromolar range. We determined the structure of diflunisal in complex with the β-clamp to show that the drug binds at subsite I, which is a protein-protein interaction site. Successful identification of FDA-approved molecules against H. pylori may lead to better and faster drug development. © 2017 Federation of European Biochemical Societies.

  1. DNA damage response clamp 9-1-1 promotes assembly of ZMM proteins for formation of crossovers and synaptonemal complex

    Science.gov (United States)

    Shinohara, Miki; Hayashihara, Kayoko; Grubb, Jennifer T.; Bishop, Douglas K.; Shinohara, Akira

    2015-01-01

    Formation of crossovers between homologous chromosomes during meiosis is positively regulated by the ZMM proteins (also known as SIC proteins). DNA damage checkpoint proteins also promote efficient formation of interhomolog crossovers. Here, we examined, in budding yeast, the meiotic role of the heterotrimeric DNA damage response clamp composed of Rad17, Ddc1 and Mec3 (known as ‘9-1-1’ in other organisms) and a component of the clamp loader, Rad24 (known as Rad17 in other organisms). Cytological analysis indicated that the 9-1-1 clamp and its loader are not required for the chromosomal loading of RecA homologs Rad51 or Dmc1, but are necessary for the efficient loading of ZMM proteins. Interestingly, the loading of ZMM proteins onto meiotic chromosomes was independent of the checkpoint kinase Mec1 (the homolog of ATR) as well as Rad51. Furthermore, the ZMM member Zip3 (also known as Cst9) bound to the 9-1-1 complex in a cell-free system. These data suggest that, in addition to promoting interhomolog bias mediated by Rad51–Dmc1, the 9-1-1 clamp promotes crossover formation through a specific role in the assembly of ZMM proteins. Thus, the 9-1-1 complex functions to promote two crucial meiotic recombination processes, the regulation of interhomolog recombination and crossover formation mediated by ZMM. PMID:25736290

  2. Introduction to Concepts in Artificial Neural Networks

    Science.gov (United States)

    Niebur, Dagmar

    1995-01-01

    This introduction to artificial neural networks summarizes some basic concepts of computational neuroscience and the resulting models of artificial neurons. The terminology of biological and artificial neurons, biological and machine learning and neural processing is introduced. The concepts of supervised and unsupervised learning are explained with examples from the power system area. Finally, a taxonomy of different types of neurons and different classes of artificial neural networks is presented.

  3. Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

    Directory of Open Access Journals (Sweden)

    Pazoki AR

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

  4. Pressure controlled clamp using shape memory alloy for minimal vessel invasion in blood flow occlusion.

    Science.gov (United States)

    Zhang, Ye; Kanetaka, Hiroyasu; Sano, Yuya; Kano, Mitsuhiro; Kudo, Tadaaki; Sato, Takumi; Shimizu, Yoshinaka

    2013-01-01

    Vessel damage after clamping may affect the success of surgical operations. A new pressure controlled clamp (SMA clamp) was designed using super elastic property of shape memory alloy (SMA) to realize atraumatic vessel occlusion. The ability and biological effect of the SMA clamp to control pressure was investigated in vivo. The loading-displacement curves of the SMA clamps (experimental group) and conventional clamp (control group) by occlusion of pig carotid arteries were evaluated using a clamping-pressure analyzing system. To investigate macroscopically and histologically the vessel damage of the SMA and conventional clamps, pig carotid arteries were stained with Evan's blue and its histological sections were stained with Elastica Massion after clamping for fifteen minutes. Constant value was shown in the loading-displacement curve of SMA clamp. In the control group, damaged area stained with Evan's blue in the vessel wall showed enlargement with the pressure increasing. Less areas in experimental groups are observed than that in the control group. Histological section in the experimental group showed no obvious except a slight compressive damage in the tunica intima. In the control group, vessel wall showed irreversible damages. This experiment indicated that the SMA clamp, which has a unique mechanical property, can be used without vessels damage. This pressure controlled clamp can be a selection in clinical apparatus to improve surgical safety.

  5. Change in the color of heat-treated, vacuum-packed broccoli stems and florets during storage: effects of process conditions and modeling by an artificial neural network.

    Science.gov (United States)

    Pero, Milad; Askari, Gholamreza; Skåra, Torstein; Skipnes, Dagbjørn; Kiani, Hossein

    2018-02-08

    Vacuum-packed broccoli stems and florets were subjected to heat treatment (60-99 °C) for various time intervals. The activity of peroxidase was measured after processing. Thermally processed samples were then stored at 4 °C for 35 days, and the color of the samples was measured every 7 days. Effects of parameters (heating temperature and duration, storage time) on the color of broccoli were modeled and simulated by an artificial neural network (ANN). Simulations confirmed that stems were predicted to be more prone to changes than florets. More color loss was observed with longer processing or storage combinations. The simulations also confirmed that higher temperatures during heat processing could retard color changes during storage. For stems treated at 80 °C for short durations, color loss was more predominant than both 65 and 99 °C, probably due to the incomplete inactivation of enzymes besides more tissue damage, with increased enzyme access to the substrate. The greenness of both stems and florets during storage can be better preserved at higher temperatures (99 °C) and short times. The simulation results revealed that the ANN method could be used as an effective tool for predicting and analyzing the color values of heat-treated broccoli. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  6. Gigaseal formation in patch clamping with applications of nanotechnology

    CERN Document Server

    Malboubi, Majid

    2014-01-01

    This book presents an investigation of gigaseal formation using micro/nanotechnology. The aims of the book are twofold. First, it explains the mechanisms of gigaseal formation using the latest discoveries. Second, it provides practical techniques for frequent formation of high resistance seals. The formation of a high-resistance electrical seal, also known as a gigaseal, between a cell membrane and a glass micropipette tip is essential in patch-clamp experiments. Even though four decades have passed since the introduction of the patch-clamping technique by Neher and Sakmann, gigaseal formation remains an obstacle in developing the high-throughput ion channel screening systems required by the pharmaceutical industry. Here the authors share their latest methods for achieving gigaseal formation and describe techniques that are highly desirable at both research and industrial levels. Nanotechnology has been found to be a powerful tool for studying and modifying glass micropipettes and in tackling the problem of g...

  7. Patch Clamp Experiments under Conditions of Variable Graviy

    Science.gov (United States)

    Kohn, F. P. M.; Meissner, K.

    2013-02-01

    The cellular membrane is an intrinsic part of any cell. It has a complex composition of lipid molecules and proteins. The membrane is, among others, involved in excitation and signal transduction. Ion channels, as integral membrane proteins, play an important role. For the question of gravity sensitivity of biological systems, especially neuronal cells, ion channels are of high interest. Gravity might directly interact with the ion channel protein or it might change the thermodynamic membrane parameters, influencing the incorporated proteins indirectly. Detailed information about the effects of gravity on the function of single ion-channels can up to now only be acquired by electrophysiological approaches like the patch clamp technique. Today this technique is the preferentially used technique for single ion-channel studies. Consequently, experiments have been developed in recent years to investigate the interaction of gravity with single ion channel molecules utilizing the patch-clamp technology on different macro- and micro-gravity platforms.

  8. Artificial Gravity

    CERN Document Server

    Clément, Gilles

    2007-01-01

    Protecting the health, safety, and performance of exploration-class mission crews against the physiological deconditioning resulting from long-term weightlessness during transit and long-term reduced gravity during surface operations will require effective, multi-system countermeasures. Artificial gravity, which would replace terrestrial gravity with inertial forces generated by rotating the transit vehicle or by short-radius human centrifuge devices within the transit vehicle or surface habitat, has long been considered a potential solution. However, despite its attractiveness as an efficient

  9. Analysis of the Pallet Clamping Conditions in Work Positioning

    OpenAIRE

    L. A. Kolesnikov

    2016-01-01

    Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and ...

  10. Modeling CICR in rat ventricular myocytes: voltage clamp studies

    Directory of Open Access Journals (Sweden)

    Palade Philip T

    2010-11-01

    Full Text Available Abstract Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR in cardiac myocytes, with voltage clamp (VC studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR, and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo. Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU, in which resides the mechanistic basis of CICR. The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel. It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its

  11. Role of the Checkpoint Clamp in DNA Damage Response

    Directory of Open Access Journals (Sweden)

    Mihoko Kai

    2013-01-01

    Full Text Available DNA damage occurs during DNA replication, spontaneous chemical reactions, and assaults by external or metabolism-derived agents. Therefore, all living cells must constantly contend with DNA damage. Cells protect themselves from these genotoxic stresses by activating the DNA damage checkpoint and DNA repair pathways. Coordination of these pathways requires tight regulation in order to prevent genomic instability. The checkpoint clamp complex consists of Rad9, Rad1 and Hus1 proteins, and is often called the 9-1-1 complex. This PCNA (proliferating cell nuclear antigen-like donut-shaped protein complex is a checkpoint sensor protein that is recruited to DNA damage sites during the early stage of the response, and is required for checkpoint activation. As PCNA is required for multiple pathways of DNA metabolism, the checkpoint clamp has also been implicated in direct roles in DNA repair, as well as in coordination of the pathways. Here we discuss roles of the checkpoint clamp in DNA damage response (DDR.

  12. Isolated PWM DC-AC SICAM with an active capacitive voltage clamp[Pulse Density Modulated; Pulse Width Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.

    2004-03-15

    In this report an isolated PWM DC-AC SICAM with an active capacitive voltage clamp is presented. AC-DC power supply is implemented in its simplest form: diode rectifier followed by a medium-size charge-storage capacitors and possibly with an EMC filter on the mains entrance. Isolation from the AC mains is achieved using a high frequency (HF) transformer, whose voltages are not audio-modulated. The latter simplifies the design and is expected to have many advantages over the approach where the transformer voltages are modulated in regards to the audio signal reference. Input stage is built as a DC-AC inverter (push-pull, half-bridge or a full-bridge) and operated with 50% duty cycle, with all the challenges to avoid transformer saturation and obtain symmetrical operation. On the secondary side the output section is implemented as rectifier+inverter AC-AC stage, i.e. a true bidirectional bridge, which operation is aimed towards amplification of the audio signal. In order to solve the problem with the commutation of the load current, a dead time between the incoming and outgoing bidirectional switch is implemented, while a capacitive voltage clamp is used to keep the induced overvoltage to reasonable levels. The energy stored in the clamping capacitor is not wasted as in the dissipative clamps, but is rather transferred back to the primary side for further processing using an auxiliary isolated single-switch converter, i.e. an active clamping technique is used. (au)

  13. Development of expert systems for modeling of technological process of pressure casting on the basis of artificial intelligence

    Science.gov (United States)

    Gavarieva, K. N.; Simonova, L. A.; Pankratov, D. L.; Gavariev, R. V.

    2017-09-01

    In article the main component of expert system of process of casting under pressure which consists of algorithms, united in logical models is considered. The characteristics of system showing data on a condition of an object of management are described. A number of logically interconnected steps allowing to increase quality of the received castings is developed

  14. Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

    KAUST Repository

    Masri, Karim M.

    2014-08-17

    We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

  15. A novel numerical technique for the high-precision simulation of flow processes related to artificial recharge

    Science.gov (United States)

    Stevens, David; Orsini, Paolo; Power, Henry; Morvan, Herve; Bensabat, Jacob

    2010-05-01

    This paper presents a novel numerical technique for large-scale groundwater flow simulations, in the frame of artificial recharge planning. The implementation is demonstrated using two test-sites from the EU funded GABARDINE project (FP6): The Sindos test site, near Thessaloniki, Greece, examines the infiltration of water towards the water table, through several unsaturated soil layers. The test site at Campina de Faro, Portugal, investigates phreatic surface movement around a large-diameter well. For both test cases a numerical simulation is constructed, and the local subsurface flow regime is investigated. Numerical methods for solving PDEs using interpolation with radial basis functions (RBFs) will typically provide high accuracy solutions, achieve excellent convergence rates, and offer great flexibility with regards to the enforcement of arbitrary boundary conditions. However, RBF methods have traditionally been limited to the solution of small academic problems, due to issues of computational cost and numerical conditioning. Recent developments in locally supported RBF methods have led to techniques which can be scaled to the largest problem sizes, while maintaining many of the flexibilities of traditional RBF methods. As a contribution to the GABARDINE project, two such numerical techniques have been developed; the meshless LHI method and the control-volume based CV-RBF method. These numerical techniques are capable of modelling flow and transport in heterogeneous porous media, and are of order-N computational complexity, allowing problems to be solved on large and irregular datasets. For both numerical techniques, the RBF Hermitian collocation method is utilised to perform interpolation at the local level, allowing the simultaneous imposition of pressure and mass-flux matching conditions at soil-layer interfaces. The non-overlapping stencil configuration then allows the accurate capture of non-smooth solution profiles across layer interfaces, to a high

  16. Microsurgical Hepatic Artery Reconstruction Using Ikuta A-II Double Clamp.

    Science.gov (United States)

    Okochi, Masayuki; Okochi, Hiromi; Sakaba, Takao; Momiyama, Masanori; Ueda, Kazuki

    2017-05-01

    We performed hepatic artery (HA) reconstruction on 24 patients between January 2010 and October 2016. Six of 24 patients used an Ikuta type A-II vascular clamp (A-II group). The mean age was 38.0 years (range, 1-61 years). There was no blood leakage at the anastomosed site in any of the patients. No patients required an additional vascular clamp, and none developed HA thrombosis. Eighteen of 24 patients used a conventional vascular clamp. The mean age was 36.1 years (range, 1-65 years; conventional group). Sixteen of 18 patients required an additional vascular clamp due to blood leakage from the HA. There was no significant difference between the 2 groups in mean age or diameter of the recipient HA. However, there was a significant difference in the proportion of patients who required an additional vascular clamp (n clamp is an effective vascular clamp for reconstruction of the HA in living donor liver transplantation.

  17. Impacts of Artificial Intelligence

    OpenAIRE

    Trappl, R.

    1986-01-01

    This book, which is intended to serve as the first stage in an iterative process of detecting, predicting, and assessing the impacts of Artificial Intelligence opens with a short "one-hour course" in AI, which is intended to provide a nontechnical informative introduction to the material which follows. Next comes an overview chapter which is based on an extensive literature search, the position papers, and discussions. The next section of the book contains position papers whose richness...

  18. Artificial perception and consciousness

    Science.gov (United States)

    Caulfield, H. John; Johnson, John L.

    2000-06-01

    Perception has both unconscious and conscious aspects. In all cases, however, what we perceive is a model of reality. By brain construction through evolution, we divide the world into two parts--our body and the outside world. But the process is the same in both cases. We perceive a construct usually governed by sensed data but always involving memory, goals, fears, expectations, etc. As a first step toward Artificial Perception in man-made systems, we examine perception in general here.

  19. Precipitation Stages and Reaction Kinetics of AlMgSi Alloys during the Artificial Aging Process Monitored by In-Situ Electrical Resistivity Measurement Method

    Directory of Open Access Journals (Sweden)

    Hong He

    2018-01-01

    Full Text Available The precipitation process and reaction kinetics during artificial aging, precipitate microstructure, and mechanical properties after aging of AlMgSi alloys were investigated employing in-situ electrical resistivity measurement, Transmission Electron Microscopy (TEM observation, and tensile test methods. Three aging stages in sequence, namely formation of GP zones, transition from GP zones to β″ phase, transition from β″ to β′ phase, and coarsening of both phases, were clearly distinguished by the variation of the resistivity. It was discussed together with the mechanical properties and precipitate morphology evolution. Fast formation of GP zones and β″ phase leads to an obvious decrease of the resistivity and increase of the mechanical strength. The formation of β″ phase in the second stage, which contributes to the peak aging strength, has much higher reaction kinetics than reactions in the other two stages. All of these stages finished faster with higher reaction kinetics under higher temperatures, due to higher atom diffusion capacity. The results proved that the in-situ electrical resistivity method, as proposed in the current study, is a simple, effective, and convenient technique for real-time monitoring of the precipitation process of AlMgSi alloys. Its further application for industrial production and scientific research is also evaluated.

  20. Modeling and Analysis of Mechanical Properties of Aluminium Alloy (A413 Processed through Squeeze Casting Route Using Artificial Neural Network Model and Statistical Technique

    Directory of Open Access Journals (Sweden)

    R. Soundararajan

    2015-01-01

    Full Text Available Artificial Neural Network (ANN approach was used for predicting and analyzing the mechanical properties of A413 aluminum alloy produced by squeeze casting route. The experiments are carried out with different controlled input variables such as squeeze pressure, die preheating temperature, and melt temperature as per Full Factorial Design (FFD. The accounted absolute process variables produce a casting with pore-free and ideal fine grain dendritic structure resulting in good mechanical properties such as hardness, ultimate tensile strength, and yield strength. As a primary objective, a feed forward back propagation ANN model has been developed with different architectures for ensuring the definiteness of the values. The developed model along with its predicted data was in good agreement with the experimental data, inferring the valuable performance of the optimal model. From the work it was ascertained that, for castings produced by squeeze casting route, the ANN is an alternative method for predicting the mechanical properties and appropriate results can be estimated rather than measured, thereby reducing the testing time and cost. As a secondary objective, quantitative and statistical analysis was performed in order to evaluate the effect of process parameters on the mechanical properties of the castings.

  1. Umbilical cord clamping at birth--practice in Norwegian maternity wards.

    Science.gov (United States)

    Lundberg, Camilla; Øian, Pål; Klingenberg, Claus

    2013-11-26

    The timing and practice used for umbilical cord clamping of neonates are controversial internationally as well as in Norway. We therefore wished to investigate routines and practices for umbilical cord clamping of neonates in Norway. A web-based questionnaire was sent to heads of departments of all maternity wards in Norway (n = 52). They were asked about their practice with regard to umbilical cord clamping of neonates and whether written routines had been prepared for this purpose. We defined early umbilical cord clamping as immediate or within 30 seconds and late clamping as ≥ 1 minute or not until pulsation in the umbilical cord had ceased. Fifty (96%) of the maternity institutions returned a completed questionnaire. Twelve institutions (24%) reported to clamp the umbilical cord of full-term neonates early, and 38 (76%) reported to practise late clamping. Nineteen maternity wards (38%) followed written routines for umbilical cord clamping of full-term neonates, and among these, early umbilical cord clamping was practised in nine (47%). In the 31 maternity wards that had no written routines, early umbilical cord clamping was practised in three (10%). Twenty-seven of the maternity wards reported that the child is placed on the maternal abdomen before clamping of the umbilical cord, 14 reported that the child commonly is held below the introitus before umbilical cord clamping, and the rest did not report any consistent practice. There is wide variation in the practice for umbilical cord clamping in Norwegian maternity wards, many of which have no written guidelines. We argue that national guidelines for umbilical cord clamping of neonates should be established.

  2. M. tuberculosis Sliding β-Clamp Does Not Interact Directly with the NAD+ -Dependent DNA Ligase

    Science.gov (United States)

    Kukshal, Vandna; Khanam, Taran; Chopra, Deepti; Singh, Nidhi; Sanyal, Sabyasachi; Ramachandran, Ravishankar

    2012-01-01

    The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp) to 3.0 Å resolution. The protein crystallized in the space group C2221 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent Kd of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD+ -dependent DNA ligase (LigA) and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria. PMID:22545130

  3. Artificial rheotaxis.

    Science.gov (United States)

    Palacci, Jérémie; Sacanna, Stefano; Abramian, Anaïs; Barral, Jérémie; Hanson, Kasey; Grosberg, Alexander Y; Pine, David J; Chaikin, Paul M

    2015-05-01

    Motility is a basic feature of living microorganisms, and how it works is often determined by environmental cues. Recent efforts have focused on developing artificial systems that can mimic microorganisms, in particular their self-propulsion. We report on the design and characterization of synthetic self-propelled particles that migrate upstream, known as positive rheotaxis. This phenomenon results from a purely physical mechanism involving the interplay between the polarity of the particles and their alignment by a viscous torque. We show quantitative agreement between experimental data and a simple model of an overdamped Brownian pendulum. The model notably predicts the existence of a stagnation point in a diverging flow. We take advantage of this property to demonstrate that our active particles can sense and predictably organize in an imposed flow. Our colloidal system represents an important step toward the realization of biomimetic microsystems with the ability to sense and respond to environmental changes.

  4. Urban wastewater process by aerobic constructed wetland; Depuracion de aguas residuales urbanas utilizando un humedal artificial aerobio

    Energy Technology Data Exchange (ETDEWEB)

    Gil Rodriguez, M.

    2007-07-01

    In this paper the experiences of urban wastewater treatment are shown in an aerobic constructed wetland, using phragmites australis.They were carried out changes on the design and operation of aerobic constructed wetlands of subsurface flow, in order to increase denitrification and biodegradation rate and to diminish the surface of the installation. the flow was channeled through a long and narrow channel to get bigger biodegradation rate to approach to the plug flow performance. the active space of process consists of two sites, one first anoxic in which denitrification takes place, and in the other one the wetland in oxygenated environment the organic matters of the wastewater are consumed by biodegradation and it takes place nitrification, and utilization of nitrates and phosphates by the vegetable culture. (Author) 14 refs.

  5. Biological artificial fluid-induced non-lamellar phases in glyceryl monooleate: the kinetics pathway and its digestive process by bile salts.

    Science.gov (United States)

    Zhou, Yanyan; Wang, Qifang; Wang, Yan; Xu, Hui; Yuan, Bo; Li, Sanming; Liu, Hongzhuo

    2014-02-01

    The cubic (Q(II)) phase is a promising sustained-release system. However, its rigid gel-like propensity is highly viscous, which makes it difficult to handle in pharmaceutical applications. To circumvent this problem, a less viscous lamellar (L(α)) phase that could spontaneously transform to Q(II) phase by the introduction of water or biological artificial fluid can be used. However, the kinetics pathway of phase transition, susceptibility to digestive processes and impact of the transition on drug release are not yet well understood. We investigated various biological artificial fluid-induced L(α) to inverse Q(II) phase transition over time in glyceryl monooleate (GMO) by water penetration scan and light polarizing microscopy. To reveal the structure stability, fluorescence spectroscopy studies were conducted using pyrene as a probe. Furthermore, the release mechanism of pyrene as a lipophilic drug model in the spontaneously formed Q(II) was investigated. Although hexagonal (H(II)) mesophases occurred when phosphate buffered saline (PBS) 7.4, 0.1 M HCl or sodium taurocholate (NaTC) solutions were introduced to GMO at room temperature, they disappear with the exception of 0.1 M HCl at 37 °C. Compared with 25 °C, L(α) to Q(II) phase transition was in a faster rate as almost completely transforms were observed after 2 h post-immersion. The spontaneously formed mesophases were stable over 24 h immersions in PBS or pancreatic lipase solutions as proven by the extremely low fluorescence signal, however they were digestible by bile salts. This result indicated that digestion by bile salts was the major pathway instead of digestion by lipases. Moreover, pyrene fluorescence spectroscopy confirmed that the digestion by bile salts induced the formation of GMO-bile salt mixed micelles whose performance depended on the bile salt concentrations. This dependence influenced the drug release from the spontaneously formed Q(II) phase. All the results concluded that

  6. Inflatable artificial sphincter

    Science.gov (United States)

    ... procedures to treat urine leakage and incontinence include: Anterior vaginal wall repair Urethral bulking with artificial material ... urinary incontinence Images Inflatable artificial sphincter Anal sphincter anatomy Inflatable artificial sphincter - series References Adams MC, Joseph ...

  7. TFE and Spt4/5 open and close the RNA polymerase clamp during the transcription cycle

    Science.gov (United States)

    Schulz, Sarah; Gietl, Andreas; Smollett, Katherine; Tinnefeld, Philip; Werner, Finn; Grohmann, Dina

    2016-01-01

    Transcription is an intrinsically dynamic process and requires the coordinated interplay of RNA polymerases (RNAPs) with nucleic acids and transcription factors. Classical structural biology techniques have revealed detailed snapshots of a subset of conformational states of the RNAP as they exist in crystals. A detailed view of the conformational space sampled by the RNAP and the molecular mechanisms of the basal transcription factors E (TFE) and Spt4/5 through conformational constraints has remained elusive. We monitored the conformational changes of the flexible clamp of the RNAP by combining a fluorescently labeled recombinant 12-subunit RNAP system with single-molecule FRET measurements. We measured and compared the distances across the DNA binding channel of the archaeal RNAP. Our results show that the transition of the closed to the open initiation complex, which occurs concomitant with DNA melting, is coordinated with an opening of the RNAP clamp that is stimulated by TFE. We show that the clamp in elongation complexes is modulated by the nontemplate strand and by the processivity factor Spt4/5, both of which stimulate transcription processivity. Taken together, our results reveal an intricate network of interactions within transcription complexes between RNAP, transcription factors, and nucleic acids that allosterically modulate the RNAP during the transcription cycle. PMID:26979960

  8. Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice.

    Science.gov (United States)

    Bayer, Kimberly

    2016-02-01

    Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds. The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse. A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping. Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation. There is a need to begin to look for populations for which delayed cord clamping can be implemented. Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.

  9. Clamped seismic metamaterials: ultra-low frequency stop bands

    Science.gov (United States)

    Achaoui, Y.; Antonakakis, T.; Brûlé, S.; Craster, R. V.; Enoch, S.; Guenneau, S.

    2017-06-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1-10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0-30 Hz.

  10. Analysis of motion during the breast clamping phase of mammography.

    Science.gov (United States)

    Ma, Wang Kei; McEntee, Mark F; Mercer, Claire; Kelly, Judith; Millington, Sara; Hogg, Peter

    2016-01-01

    To measure paddle motion during the clamping phase of a breast phantom for a range of machine/paddle combinations. A deformable breast phantom was used to simulate a female breast. 12 mammography machines from three manufacturers with 22 flexible and 20 fixed paddles were evaluated. Vertical motion at the paddle was measured using two calibrated linear potentiometers. For each paddle, the motion in millimetres was recorded every 0.5 s for 40 s, while the phantom was compressed with 80 N. Independent t-tests were used to determine differences in paddle motion between flexible and fixed, small and large, GE Senographe Essential (General Electric Medical Systems, Milwaukee, WI) and Hologic Selenia Dimensions paddles (Hologic, Bedford, MA). Paddle tilt in the medial-lateral plane for each machine/paddle combination was calculated. All machine/paddle combinations demonstrate highest levels of motion during the first 10 s of the clamping phase. The least motion is 0.17 ± 0.05 mm/10 s (n = 20) and the most motion is 0.51 ± 0.15 mm/10 s (n = 80). There is a statistical difference in paddle motion between fixed and flexible (p Hologic Selenia Dimensions paddles (p < 0.001). Paddle tilt in the medial-lateral plane is independent of time and varied from 0.04 ° to 0.69 °. All machine/paddle combinations exhibited motion and tilting, and the extent varied with machine and paddle sizes and types. This research suggests that image blurring will likely be clinically insignificant 4 s or more after the clamping phase commences.

  11. Wide Band Artificial Pulsar

    Science.gov (United States)

    Parsons, Zackary

    2017-01-01

    The Wide Band Artificial Pulsar (WBAP) is an instrument verification device designed and built by the National Radio Astronomy Observatory (NRAO) in Green Bank, West Virgina. The site currently operates the Green Bank Ultimate Pulsar Processing Instrument (GUPPI) and the Versatile Green Bank Astronomical Spectrometer (VEGAS) digital backends for their radio telescopes. The commissioning and continued support for these sophisticated backends has demonstrated a need for a device capable of producing an accurate artificial pulsar signal. The WBAP is designed to provide a very close approximation to an actual pulsar signal. This presentation is intended to provide an overview of the current hardware and software implementations and to also share the current results from testing using the WBAP.

  12. A direct proofreader-clamp interaction stabilizes the Pol III replicase in the polymerization mode

    KAUST Repository

    Jergic, Slobodan

    2013-02-22

    Processive DNA synthesis by the αÉ"θ core of the Escherichia coli Pol III replicase requires it to be bound to the β 2 clamp via a site in the α polymerase subunit. How the É" proofreading exonuclease subunit influences DNA synthesis by α was not previously understood. In this work, bulk assays of DNA replication were used to uncover a non-proofreading activity of É". Combination of mutagenesis with biophysical studies and single-molecule leading-strand replication assays traced this activity to a novel β-binding site in É" that, in conjunction with the site in α, maintains a closed state of the αÉ"θ-β 2 replicase in the polymerization mode of DNA synthesis. The É"-β interaction, selected during evolution to be weak and thus suited for transient disruption to enable access of alternate polymerases and other clamp binding proteins, therefore makes an important contribution to the network of protein-protein interactions that finely tune stability of the replicase on the DNA template in its various conformational states. © 2013 European Molecular Biology Organization.

  13. Shape of a clamped stiff harpsichord wire driven at a resonant frequency

    Science.gov (United States)

    Hanson, Roger J.; Macomber, Hilliard Kent; Boucher, Mathew A.

    2002-05-01

    A wire transversely driven by a sinusoidal force at the resonant frequency of a vibrational mode vibrates at the driving frequency and at harmonics generated by nonlinear processes in the wire. If the amplitude of a harmonic is measured as a function of position along the wire, its shape is revealed. It differs significantly from a sinusoid in the vicinity of either end of the wire because the ends are clamped and the wire has significant stiffness. The shapes of various harmonics have been determined for a brass harpsichord wire, 70 cm long, from optical detector measurements made at different distances from a clamped end. Knowledge of shape facilitates the determination of antinode amplitudes of harmonics when the gross motion of the wire is so large that the detectors must be positioned near an end of the wire because of their very limited dynamic range. Some observations of harmonics and related phenomena were reported previously [Hanson et al., J. Acoust Soc. Am. 108, 2592 (2000); 106, 2141 (1999)]. The shape information is also needed to help separate nonlinear effects possibly occurring in the detectors from those of interest, occurring in the wire itself.

  14. cryo-EM structures of the E. coli replicative DNA polymerase reveal its dynamic interactions with the DNA sliding clamp, exonuclease and τ

    Science.gov (United States)

    Fernandez-Leiro, Rafael; Conrad, Julian; Scheres, Sjors HW; Lamers, Meindert H

    2015-01-01

    The replicative DNA polymerase PolIIIα from Escherichia coli is a uniquely fast and processive enzyme. For its activity it relies on the DNA sliding clamp β, the proofreading exonuclease ε and the C-terminal domain of the clamp loader subunit τ. Due to the dynamic nature of the four-protein complex it has long been refractory to structural characterization. Here we present the 8 Å resolution cryo-electron microscopy structures of DNA-bound and DNA-free states of the PolIII-clamp-exonuclease-τc complex. The structures show how the polymerase is tethered to the DNA through multiple contacts with the clamp and exonuclease. A novel contact between the polymerase and clamp is made in the DNA bound state, facilitated by a large movement of the polymerase tail domain and τc. These structures provide crucial insights into the organization of the catalytic core of the replisome and form an important step towards determining the structure of the complete holoenzyme. DOI: http://dx.doi.org/10.7554/eLife.11134.001 PMID:26499492

  15. [Time of cord clamping and neonatal complications, a prospective study].

    Science.gov (United States)

    Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

    2014-09-01

    To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (<60 seconds), group 2 (1 to<2 minutes), and group 3 (2 to 3 minutes). Laboratory tests were performed at birth and at 48 hours of life, assessing the levels of hemoglobin, hematocrit, ferritin, and bilirubin. The risk of polycythemia, respiratory distress syndrome, neonatal phototherapy or admission to the Intensive Care Unit and the hospital stay, were evaluated. A total of 242 patients were included: group 1 (g1=80), group 2 (g2=31) y group 3 (g3=131). The background maternal and neonatal characteristics were similar in all sets. The first test showed significant differences in ferritin levels in those infants with delayed clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; p<0.01). In the second analysis the values of hemoglobin (g1: 17.3 g/dl, g2: 18.9 g/dl, g3: 19.2 g/dl; p<0.01), hematocrit (g1: 53.4%, g2: 58%, g3: 59%; p<0.01) and ferritin (g1: 254 mg/dl, g2: 254.7 mg/dl, g3: 313 mg/dl; p = 0.008) were statistically higher in this group. As regards complications, a significant increase was observed in the number of cases of polycythemia symptoms in group 3. The late cord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  16. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    Science.gov (United States)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  17. PWM Regulation of Grid-Tied PV System on the Base of Photovoltaic-Fed Diode-Clamped Inverters

    Directory of Open Access Journals (Sweden)

    Oleschuk V.I.

    2015-12-01

    Full Text Available Investigation of grid-tied photovoltaic system on the base of two diode-clamped inverters, controlled by specific algorithms of pulse-width modulation (PWM, has been done. This system includes two strings of photovoltaic panels feeding two diode-clamped inverters. The outputs of inverters are connected with the corresponding windings on the primary side of three-phase transformer, connected with a grid. In order to reduce phase voltage distortion and to increase efficiency of operation of the system, special scheme of control and modulation of inverters has been used, providing minimization of common-mode voltages and voltage waveforms symmetries under different operating conditions. Detailed simulation of processes in this photovoltaic-fed power conversion system has been executed. The results of simulations verify good performance of photovoltaic system regulated in accordance with specific strategy of control and modulation.

  18. How linguistic descriptions of data can help to the teaching-learning process in higher education, case of study: artificial intelligence

    OpenAIRE

    Rubio-Manzano, Clemente; Senoceain, Tomas Lermanda

    2017-01-01

    Artificial Intelligence is a central topic in the computer science curriculum. From the year 2011 a project-based learning methodology based on computer games has been designed and implemented into the intelligence artificial course at the University of the Bio-Bio. The project aims to develop software-controlled agents (bots) which are programmed by using heuristic algorithms seen during the course. This methodology allows us to obtain good learning results, however several challenges have b...

  19. Load-deflection characteristics of small-bore insulated-pipe clamps

    International Nuclear Information System (INIS)

    Severud, L.K.; Clark, G.L.

    1981-12-01

    The special insulated clamps used on both FFTF and CRBR piping utilize a Belleville spring arrangement to compensate for pipe thermal expansion. Analysis indicates that this produces a non-linear, directionally sensitive clamp spring rate. Since these spring rates influence the seismic response of a supported piping system, it was deemed necessary to evaluate them further by test. This has been accomplished for the FFTF clamps. A more standard insulated pipe clamp, which does not incorporate Belleville springs to accommodate thermal expansion, was also tested. This type clamp is simple in design, and economically attractive. It may have wide application prospects for use in LMFBR small bore auxiliary piping operating at temperatures below 427 0 C. Load deflection tests were conducted on 2.54 CM and 7.62 CM diameter samples of these commercial clamps

  20. Renal function is the same 6 months after robot-assisted partial nephrectomy regardless of clamp technique: analysis of outcomes for off-clamp, selective arterial clamp and main artery clamp techniques, with a minimum follow-up of 1 year.

    Science.gov (United States)

    Komninos, Christos; Shin, Tae Young; Tuliao, Patrick; Han, Woong Kyu; Chung, Byung Ha; Choi, Young Deuk; Rha, Koon Ho

    2015-06-01

    To compare the renal functional outcomes, with >1 year of follow-up, of patients who underwent robot-assisted partial nephrectomy (RAPN) performed with different clamping techniques. The peri-operative data of patients undergoing RAPN performed with different clamping techniques were retrospectively analysed (group 1: off-clamp, n = 23; group 2: selective clamp, n = 25; group 3: main artery clamp, n = 114). The main outcome measures were postoperative serum creatinine level, estimated glomerular filtration rate (eGFR) and percentage change in eGFR, the data for which were collected at periodic intervals during the first 12 months and annually thereafter, in addition to late eGFR value. Only patients with >1 year of follow-up were included in the analysis. The baseline characteristics of groups 2 and 3 were similar, while patients in group 1 had smaller sized tumours and lower tumour complexity. The median follow-up periods were 45 (group 1), 20 (group 2) and 47 (group 3) months. The median clamping times were 24.8 min in the main artery clamp and 18 min in the selective artery clamp groups. Group 2 had greater median blood loss volume (100 vs 500 vs 200 mL for groups 1, 2 and 3, respectively; P clamp procedure and tumour complexity score were predictive of normal renal function 7 days after surgery, while only baseline eGFR and age could predict it 1 year postoperatively. Off-clamp and selective artery clamp techniques result in superior short-term renal functional outcomes compared with the main artery clamp approach; however, after the 6th postoperative month, there were no significant differences regarding the functional outcome among the above surgical techniques, as long as the warm ischaemia time was 20-30 min. © 2014 The Authors BJU International © 2014 BJU International.

  1. Mechanism of loading the Escherichia coli DNA polymerase III beta sliding clamp on DNA. Bona fide primer/templates preferentially trigger the gamma complex to hydrolyze ATP and load the clamp.

    Science.gov (United States)

    Ason, Brandon; Handayani, Renita; Williams, Christopher R; Bertram, Jeffrey G; Hingorani, Manju M; O'Donnell, Mike; Goodman, Myron F; Bloom, Linda B

    2003-03-21

    The Escherichia coli DNA polymerase III gamma complex clamp loader assembles the ring-shaped beta sliding clamp onto DNA. The core polymerase is tethered to the template by beta, enabling processive replication of the genome. Here we investigate the DNA substrate specificity of the clamp-loading reaction by measuring the pre-steady-state kinetics of DNA binding and ATP hydrolysis using elongation-proficient and deficient primer/template DNA. The ATP-bound clamp loader binds both elongation-proficient and deficient DNA substrates either in the presence or absence of beta. However, elongation-proficient DNA preferentially triggers gamma complex to release beta onto DNA with concomitant hydrolysis of ATP. Binding to elongation-proficient DNA converts the gamma complex from a high affinity ATP-bound state to an ADP-bound state having a 10(5)-fold lower affinity for DNA. Steady-state binding assays are misleading, suggesting that gamma complex binds much more avidly to non-extendable primer/template DNA because recycling to the high affinity binding state is rate-limiting. Pre-steady-state rotational anisotropy data reveal a dynamic association-dissociation of gamma complex with extendable primer/templates leading to the diametrically opposite conclusion. The strongly favored dynamic recognition of extendable DNA does not require the presence of beta. Thus, the gamma complex uses ATP binding and hydrolysis as a mechanism for modulating its interaction with DNA in which the ATP-bound form binds with high affinity to DNA but elongation-proficient DNA substrates preferentially trigger hydrolysis of ATP and conversion to a low affinity state.

  2. Reconhecimento de variedades de soja por meio do processamento de imagens digitais usando redes neurais artificiais Soybean varieties recognition through the digital image processing using artificial neural network

    Directory of Open Access Journals (Sweden)

    Oleg Khatchatourian

    2008-12-01

    Full Text Available Neste trabalho, foi aplicado o processamento de imagens digitais auxiliado pelas Redes Neurais Artificiais (RNA com a finalidade de identificar algumas variedades de soja por meio da forma e do tamanho das sementes. Foram analisadas as seguintes variedades: EMBRAPA 133, EMBRAPA 184, COODETEC 205, COODETEC 206, EMBRAPA 48, SYNGENTA 8350, FEPAGRO 10 e MONSOY 8000 RR, safra 2005/2006. O processamento das imagens foi constituído pelas seguintes etapas: 1 Aquisição da imagem: as amostras de cada variedade foram fotografadas por máquina fotográfica Coolpix995, Nikon, com resolução de 3.34 megapixels; 2 Pré-processamento: um filtro de anti-aliasing foi aplicado para obter tons acinzentados da imagem; 3 Segmentação: foi realizada a detecção das bordas das sementes (Método de Prewitt, dilatação dessas bordas e remoção de segmentos não-necessários para a análise. 4 Representação: cada semente foi representada na forma de matriz binária 130x130, e 5 Reconhecimento e interpretação: foi utilizada uma rede neural feedforward multicamadas, com três camadas ocultas. O treinamento da rede foi realizado pelo método backpropagation. A validação da RNA treinada mostrou que o processamento aplicado pode ser usado para a identificação das variedades consideradas.Digital image processing with Artificial Neural Network (ANN was used to identify some soybean varieties through the form and size of the seeds. The following varieties were analyzed: EMBRAPA 133, EMBRAPA 184, COODETEC 205, COODETEC 206, EMBRAPA 48, SYNGENTA 8350, FEPAGRO 10 and MONSOY 8000 RR, 2005/2006 harvest. The image processing was constituted by the following stages: 1 Image acquisition: the samples of each variety were photographed by photographic camera Coolpix995, Nikon, with resolution of 3.34 megapixels; 2 Pre-processing: an anti-aliasing filter was applied to convert the true-color image to the grayscale intensity image; 3 Segmentation: it was made the seeds edges

  3. Modeling of SVM Diode Clamping Three-Level Inverter Connected to Grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    PLECS is used to model the diode clamping three-level inverter connected to grid and good results are obtained. First the output voltage SVM is described for diode clamping three-level inverter with loads connected to Y. Then the output voltage SVM of diode clamping three-level inverter is simply...... analyzed with loads connected to △. But it will be further researched in the future. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping three-level inverter is briefly presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS...

  4. Cryogenic Clamp-on Ultrasonic Flowmeters using Single Crystal Piezoelectric Transducers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Clamp-on ultrasound cryogenic flowmeters using single crystal piezoelectric transducers are proposed to enable reliable, accurate cryogenic instrumentation needs in...

  5. Three-dimensional renal CT angiography for guiding segmental renal artery clamping during laparoscopic partial nephrectomy

    International Nuclear Information System (INIS)

    Xu, Yi; Shao, Pengfei; Zhu, Xiaomei; Lv, Qiang; Liu, Wangyan; Xu, Hai; Zhu, Yinsu; Yang, Guangyu; Tang, Lijun; Yin, Changjun

    2013-01-01

    Aim: To evaluate the effectiveness of three-dimensional (3D) renal computed tomography angiography (CTA) in guiding segmental renal artery clamping during laparoscopic partial nephrectomy (LPN). Materials and methods: Forty-three patients with renal tumours undergoing renal CTA before LPN were retrospectively enrolled in this study. 3D arteriogram reconstructed images were created to identify the renal tumour-supplying arteries. The number and location of these targeted vessels were annotated on 3D images preoperatively and compared with the clamped vessels during LPN. The consistency between target vessels annotated at CTA and clamped arteries at LPN was compared both using a patient-based analysis and vessel-based analysis. The χ 2 test was applied to analyse the influence of tumour size, location, and growth pattern on the number of clamped segmental renal branches. Results: On patient-based analysis, the number of targeted vessels was consistent with the clamped vessels during LPN in 33 of 43 patients. On vessel-based analysis, 56 of 65 target vessels annotated at CTA were clamped during LPN. More segmental renal branches (p = 0.04) were clamped in patients with tumours of larger size. Tumour location and growth pattern had no association with the number of clamped segmental branches during LPN. Conclusion: High-quality CTA images and 3D reconstruction images can detect detailed information of tumour-supplying arteries to renal tumours. 3D renal CTA is an effective way to guide segmental renal artery clamping during LPN

  6. From understanding cellular function to novel drug discovery: the role of planar patch-clamp array chip technology

    Directory of Open Access Journals (Sweden)

    Christophe ePy

    2011-10-01

    Full Text Available All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor-intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, resulting in questionable models of true physiological function, and are unsuitable for studies involving neuronal communication. Multi-electrode arrays (MEA, in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, the approach to the chemical patterning for cell placement, and present physiological data from cultured neuronal cells.

  7. Adsorptive removal of arsenic by novel iron/olivine composite: Insights into preparation and adsorption process by response surface methodology and artificial neural network.

    Science.gov (United States)

    Ghosal, Partha S; Kattil, Krishna V; Yadav, Manoj K; Gupta, Ashok K

    2018-03-01

    Olivine, a low-cost natural material, impregnated with iron is introduced in the adsorptive removal of arsenic. A wet impregnation method and subsequent calcination were employed for the preparation of iron/olivine composite. The major preparation process parameter, viz., iron loading and calcination temperature were optimized through the response surface methodology coupled with a factorial design. A significant variation of adsorption capacity of arsenic (measured as total arsenic), i.e., 63.15 to 310.85 mg/kg for arsenite [As(III) T ] and 76.46 to 329.72 mg/kg for arsenate [As(V) T ] was observed, which exhibited the significant effect of the preparation process parameters on the adsorption potential. The iron loading delineated the optima at central points, whereas a monotonous decreasing trend of adsorption capacity for both the As(III) T and As(V) T was observed with the increasing calcination temperature. The variation of adsorption capacity with the increased iron loading is more at lower calcination temperature showing the interactive effect between the factors. The adsorbent prepared at the optimized condition of iron loading and calcination temperature, i.e., 10% and 200 °C, effectively removed the As(III) T and As(V) T by more than 96 and 99%, respectively. The material characterization of the adsorbent showed the formation of the iron compound in the olivine and increase in specific surface area to the tune of 10 multifold compared to the base material, which is conducive to the enhancement of the adsorption capacity. An artificial neural network was applied for the multivariate optimization of the adsorption process from the experimental data of the univariate optimization study and the optimized model showed low values of error functions and high R 2 values of more than 0.99 for As(III) T and As(V) T . The adsorption isotherm and kinetics followed Langmuir model and pseudo second order model, respectively demonstrating the chemisorption in this

  8. Artificial mismatch hybridization

    Science.gov (United States)

    Guo, Zhen; Smith, Lloyd M.

    1998-01-01

    An improved nucleic acid hybridization process is provided which employs a modified oligonucleotide and improves the ability to discriminate a control nucleic acid target from a variant nucleic acid target containing a sequence variation. The modified probe contains at least one artificial mismatch relative to the control nucleic acid target in addition to any mismatch(es) arising from the sequence variation. The invention has direct and advantageous application to numerous existing hybridization methods, including, applications that employ, for example, the Polymerase Chain Reaction, allele-specific nucleic acid sequencing methods, and diagnostic hybridization methods.

  9. An analytical model of a clamped sandwich beam under low-impulse mass impact

    Directory of Open Access Journals (Sweden)

    Wen-zheng Jiang

    Full Text Available An analytical model is developed to examine a low impulsive projectile impact on a fully clamped sandwich beams by considering the coupled responses of the core and the face sheets. Firstly, based on the dynamic properties of foam cores, the sandwich beam is modeled as two rigid perfectly-plastic beams connected by rigid perfectly-plastic springs. Different from the previous sandwich beam model, the transverse compression and bending effects of the foam core are considered in the whole deformation process. Based on this model, different coupling mechanism of sandwich beams are constructed so that an analytical solution considering small deformation is derived. The coupled dynamic responses of sandwich beams with different core strengths are investigated. The results indicate that this model improves the prediction accuracy of the responses of the sandwich beams, and is available for the situation when the sandwich beam undergoes moderate global deformation.

  10. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...... modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts...

  11. Comparative Evaluation of Pulsewidth Modulation Strategies for Z-Source Neutral-Point-Clamped Inverter

    DEFF Research Database (Denmark)

    Loh, P.C.; Blaabjerg, Frede; Wong, C.P.

    2007-01-01

    modulation (PWM) strategies for controlling the Z-source NPC inverter. While developing the PWM techniques, attention has been devoted to carefully derive them from a common generic basis for improved portability, easier implementation, and most importantly, assisting readers in understanding all concepts......Z-source neutral-point-clamped (NPC) inverter has recently been proposed as an alternative three-level buck-boost power conversion solution with an improved output waveform quality. In principle, the designed Z-source inverter functions by selectively "shooting through" its power sources, coupled...... to the inverter using two unique Z-source impedance networks, to boost the inverter three-level output waveform. Proper modulation of the new inverter would therefore require careful integration of the selective shoot-through process to the basic switching concepts to achieve maximal voltage-boost, minimal...

  12. Clamped end conditions and cross section deformation in the finite element absolute nodal coordinate formulation

    International Nuclear Information System (INIS)

    Hussein, Bassam A.; Weed, David; Shabana, Ahmed A.

    2009-01-01

    In the finite element absolute nodal coordinate formulation (ANCF), the elimination of the relative translations and rotations at a point does not necessarily define a fully clamped joint, particularly in the case of fully parameterized ANCF finite elements that allow for the deformation of the cross section. In this investigation, the formulations and results of two different sets of clamped end conditions that define two different joints are compared. The first joint, called the partially clamped joint, eliminates only the translations and rotations at a point on the cross section. The second joint, called the fully clamped joint, eliminates all the translation, rotation and deformation degrees of freedom at a point on the cross section. The kinematic equations that define the partially and fully clamped joints are developed, and the dynamic equations used in the comparative numerical study presented in this paper are shown. As discussed in this investigation, the fully clamped joint does not allow for the deformation of the cross section at the joint node since the gradient vectors remain orthogonal unit vectors. The partially clamped joint, on the other hand, allows for the deformation of the cross section. Nanson's formula is used as a measure of the deformation of the cross section in the case of the partially clamped joint. A very flexible pendulum that has a rigid body attached to its free end is used to compare the results of the partially and fully clamped joints. The numerical results obtained using this very flexible pendulum example show that, while the type of joint (partially or fully clamped) does not significantly affect the gross reference motion of the system, there are fundamental differences between the two joints since the partially clamped joint allows for the cross section deformations at the joint node

  13. Renal Vascular Clamp Placement: A Potential Cause of Incomplete Hilar Control during Partial Nephrectomy.

    Science.gov (United States)

    Tryon, David; Myklak, Kristene; Alsyouf, Muhannad; Conceicao, Carol; Peplinski, Brandon; Arenas, Javier L; Faaborg, Daniel; Ruckle, Herbert C; Baldwin, D Duane

    2016-03-01

    Previous benchtop studies have shown that robotic bulldog clamps provide incomplete vascular control of a Penrose drain. We determined the efficacy of robotic and laparoscopic bulldog clamps to ensure hemostasis on the human renal artery. The effect of clamp position on vascular control was also examined. Fresh human cadaveric renal arteries were used to determine the leak point pressure of 7 bulldog clamps from a total of 3 manufacturers. Five trials were performed per clamp at 4 locations, including the fulcrum, proximal, middle and distal positions. Comparison was done using the Kruskal-Wallis test with p clamps leaked at a pressure less than 215 mm Hg when applied at the proximal, middle or distal position. In general leak point pressure decreased as the artery was positioned more distal along the clamp. The exception was when the vessel was placed at the fulcrum position. At that position 80% to 100% of trials with the Klein laparoscopic, 100% with the Klein robotic (Klein Robotic, San Antonio, Texas) and 60% to 80% with the Scanlan robotic (Scanlan International, Saint Paul, Minnesota) clamp leaked at pressure below 215 mm Hg. Each vascular clamp adequately occluded flow at physiological pressure when placed at the proximal, middle or distal position. Furthermore, these results demonstrate that there is leakage at physiological pressure when the artery is placed at the fulcrum of certain clamp types. These results suggest that applying a bulldog clamp at the fulcrum could potentially lead to inadequate vessel occlusion and intraoperative bleeding. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  14. Electrothermally actuated tunable clamped-guided resonant microbeams

    KAUST Repository

    Alcheikh, Nouha

    2017-06-11

    We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide–range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

  15. Floating clamping mechanism of PT fuel injector and its dynamic characteristics analysis

    Science.gov (United States)

    Wang, Xinqing; Liang, Sheng; Xia, Tian; Wang, Dong; Qian, Shuhua

    2012-05-01

    PT fuel injector is one of the most important parts of modern diesel engine. To satisfy the requirements of the rapid and accurate test of PT fuel injector, the self-adaptive floating clamping mechanism was developed and used in the relevant bench. Its dynamic characteristics directly influence the test efficiency and accuracy. However, due to its special structure and complex oil pressure signal, related documents for evaluating dynamic characteristics of this mechanism are lack and some dynamic characteristics of this mechanism can't be extracted and recognized effectively by traditional methods. Aiming at the problem above-mentioned, a new method based on Hilbert-Huang transform (HHT) is presented. Firstly, combining with the actual working process, the dynamic liquid pressure signal of the mechanism is acquired. By analyzing the pressure fluctuation during the whole working process in time domain, oil leakage and hydraulic shock in the clamping chamber are discovered. Secondly, owing to the nonlinearity and nonstationarity of pressure signal, empirical mode decomposition is used, and the signal is decomposed and reconstructed into forced vibration, free vibration and noise. By analyzing forced vibration in the time domain, machining error and installation error of cam are revealed. Finally, free vibration component is analyzed in time-frequency domain with HHT, the traits of free vibration in the time-frequency domain are revealed. Compared with traditional methods, Hilbert spectrum has higher time-frequency resolutions and higher credibility. The improved mechanism based on the above analyses can guarantee the test accuracy of injector injection. This new method based on the analyses of the pressure signal and combined with HHT can provide scientific basis for evaluation, design improvement of the mechanism, and give references for dynamic characteristics analysis of the hydraulic system in the interrelated fields.

  16. Computational aerodynamics and artificial intelligence

    Science.gov (United States)

    Kutler, P.; Mehta, U. B.

    1984-01-01

    Some aspects of artificial intelligence are considered and questions are speculated on, including how knowledge-based systems can accelerate the process of acquiring new knowledge in aerodynamics, how computational fluid dynamics may use 'expert' systems and how expert systems may speed the design and development process. The anatomy of an idealized expert system called AERODYNAMICIST is discussed. Resource requirements are examined for using artificial intelligence in computational fluid dynamics and aerodynamics. Considering two of the essentials of computational aerodynamics - reasoniing and calculating - it is believed that a substantial part of the reasoning can be achieved with artificial intelligence, with computers being used as reasoning machines to set the stage for calculating. Expert systems will probably be new assets of institutions involved in aeronautics for various tasks of computational aerodynamics.

  17. Crystal structure of DNA polymerase III β sliding clamp from Mycobacterium tuberculosis.

    Science.gov (United States)

    Gui, Wen-Jun; Lin, Shi-Qiang; Chen, Yuan-Yuan; Zhang, Xian-En; Bi, Li-Jun; Jiang, Tao

    2011-02-11

    The sliding clamp is a key component of DNA polymerase III (Pol III) required for genome replication. It is known to function with diverse DNA repair proteins and cell cycle-control proteins, making it a potential drug target. To extend our understanding of the structure/function relationship of the sliding clamp, we solved the crystal structure of the sliding clamp from Mycobacterium tuberculosis (M. tuberculosis), a human pathogen that causes most cases of tuberculosis (TB). The sliding clamp from M. tuberculosis forms a ring-shaped head-to-tail dimer with three domains per subunit. Each domain contains two α helices in the inner ring that lie against two β sheets in the outer ring. Previous studies have indicated that many Escherichia coli clamp-binding proteins have a conserved LF sequence, which is critical for binding to the hydrophobic region of the sliding clamp. Here, we analyzed the binding affinities of the M. tuberculosis sliding clamp and peptides derived from the α and δ subunits of Pol III, which indicated that the LF motif also plays an important role in the binding of the α and δ subunits to the sliding clamp of M. tuberculosis. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Application of active electrode compensation to perform continuous voltage-clamp recordings with sharp microelectrodes.

    Science.gov (United States)

    Gómez-González, J F; Destexhe, A; Bal, T

    2014-10-01

    Electrophysiological recordings of single neurons in brain tissues are very common in neuroscience. Glass microelectrodes filled with an electrolyte are used to impale the cell membrane in order to record the membrane potential or to inject current. Their high resistance induces a high voltage drop when passing current and it is essential to correct the voltage measurements. In particular, for voltage clamping, the traditional alternatives are two-electrode voltage-clamp technique or discontinuous single electrode voltage-clamp (dSEVC). Nevertheless, it is generally difficult to impale two electrodes in a same neuron and the switching frequency is limited to low frequencies in the case of dSEVC. We present a novel fully computer-implemented alternative to perform continuous voltage-clamp recordings with a single sharp-electrode. To reach such voltage-clamp recordings, we combine an active electrode compensation algorithm (AEC) with a digital controller (AECVC). We applied two types of control-systems: a linear controller (proportional plus integrative controller) and a model-based controller (optimal control). We compared the performance of the two methods to dSEVC using a dynamic model cell and experiments in brain slices. The AECVC method provides an entirely digital method to perform continuous recording and smooth switching between voltage-clamp, current clamp or dynamic-clamp configurations without introducing artifacts.

  19. A structural and mechanistic study of π-clamp-mediated cysteine perfluoroarylation.

    Science.gov (United States)

    Dai, Peng; Williams, Jonathan K; Zhang, Chi; Welborn, Matthew; Shepherd, James J; Zhu, Tianyu; Van Voorhis, Troy; Hong, Mei; Pentelute, Bradley L

    2017-08-11

    Natural enzymes use local environments to tune the reactivity of amino acid side chains. In searching for small peptides with similar properties, we discovered a four-residue π-clamp motif (Phe-Cys-Pro-Phe) for regio- and chemoselective arylation of cysteine in ribosomally produced proteins. Here we report mutational, computational, and structural findings directed toward elucidating the molecular factors that drive π-clamp-mediated arylation. We show the significance of a trans conformation prolyl amide bond for the π-clamp reactivity. The π-clamp cysteine arylation reaction enthalpy of activation (ΔH ‡ ) is significantly lower than a non-π-clamp cysteine. Solid-state NMR chemical shifts indicate the prolyl amide bond in the π-clamp motif adopts a 1:1 ratio of the cis and trans conformation, while in the reaction product Pro3 was exclusively in trans. In two structural models of the perfluoroarylated product, distinct interactions at 4.7 Å between Phe1 side chain and perfluoroaryl electrophile moiety are observed. Further, solution 19 F NMR and isothermal titration calorimetry measurements suggest interactions between hydrophobic side chains in a π-clamp mutant and the perfluoroaryl probe. These studies led us to design a π-clamp mutant with an 85-fold rate enhancement. These findings will guide us toward the discovery of small reactive peptides to facilitate abiotic chemistry in water.

  20. Soil architecture relationships with dynamic soil physical processes: a conceptual study using natural, artificial, and 3D-printed soil cores

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per; Dal Ferro, Nicola

    (topsoil and subsoil), representing contrasting soil pore systems. Cylinders (100 cm3) were produced from plastic or from autoclaved aerated concrete. Holes of diameters 1.5 and 3 mm were drilled in the cylinder direction for the plastic cylinder and for one of the AAC cylinders. All natural and artificial...

  1. Analysis of failed and nickel-coated 3093 beam clamp components at the East Tennessee Technology Park (ETTP).

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D.; Pappacena, K.; Gaviria, J.; Burtsteva, T.; Nuclear Engineering Division

    2010-10-11

    The U.S. Department of Energy and its contractor, Bechtel Jacobs Company (BJC), are undertaking a major effort to clean up the former gaseous diffusion facility (K-25) located in Oak Ridge, TN. The decontamination and decommissioning activities require systematic removal of contaminated equipment and machinery followed by demolition of the buildings. As part of the cleanup activities, a beam clamp, used for horizontal life lines (HLLs) for fall protection, was discovered to be fractured during routine inspection. The beam clamp (yoke and D-ring) was a component in the HLL system purchased from Reliance Industries LLC. Specifically, the U-shaped stainless steel yoke of the beam clamp failed in a brittle mode at under less than 10% of the rated design capacity of 14,500 lb. The beam clamp had been in service for approximately 16 months. Bechtel Jacobs approached Argonne National Laboratory to assist in identifying the root cause of the failure of the beam clamp. The objectives of this study were to (1) review the prior reports and documents on the subject, (2) understand the possible failure mechanism(s) that resulted in the failed beam clamp components, (3) recommend approaches to mitigate the failure mechanism(s), and (4) evaluate the modified beam clamp assemblies. Energy dispersive x-ray analysis and chemical analysis of the corrosion products on the failed yoke and white residue on an in-service yoke indicated the presence of zinc, sulfur, and calcium. Analysis of rainwater in the complex, as conducted by BJC, indicated the presence of sulfur and calcium. It was concluded that, as a result of galvanic corrosion, zinc from the galvanized components of the beam clamp assembly (D-ring) migrated to the corroded region in the presence of the rainwater. Under mechanical stress, the corrosion process would have accelerated, resulting in the catastrophic failure of the yoke. As suggested by Bechtel Jacobs personnel, hydrogen embrittlement as a consequence of corrosion

  2. Diuretic response to acute hypertension is blunted during angiotensin II clamp

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Zhang, Yibin; Yang, Li E

    2002-01-01

    and endogenous lithium clearance increased two- and threefold, respectively. We conclude that HOE-140, an inhibitor of the B(2) receptor, potentiates the sensitivity of arterial pressure to ANG II and that clamping systemic ANG II levels during acute hypertension blunts the magnitude of the pressure diuretic...... whether the suppression of the renin-angiotensin system during acute hypertension affects the magnitude of the inhibition of PT fluid and sodium reabsorption, plasma ANG II levels were clamped by infusion of the angiotensin-converting enzyme (ACE) inhibitor captopril (12 microg/min) and ANG II after...... ("ANG II clamp"). When blood pressure was acutely increased 50-60 mmHg by arterial constriction without ANG II clamp, urine output and endogenous lithium clearance increased 4.0- and 6.7-fold, respectively. With ANG II clamp, the effects of acute hypertension were reduced 50%: urine output...

  3. A reduction clamp for an aiming component in associated acetabular fractures

    Directory of Open Access Journals (Sweden)

    Zhang-Fu Wang

    2015-01-01

    Full Text Available Background: The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. Materials and Methods: In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. Results: This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp′s aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. Conclusion: This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  4. Artificial Intelligence--Applications in Education.

    Science.gov (United States)

    Poirot, James L.; Norris, Cathleen A.

    1987-01-01

    This first in a projected series of five articles discusses artificial intelligence and its impact on education. Highlights include the history of artificial intelligence and the impact of microcomputers; learning processes; human factors and interfaces; computer assisted instruction and intelligent tutoring systems; logic programing; and expert…

  5. On the Design of Artificial Stock Markets

    NARCIS (Netherlands)

    K. Boer-Sorban (Katalin); A. de Bruin (Arie); U. Kaymak (Uzay)

    2005-01-01

    textabstractArtificial stock markets are designed with the aim to study and understand market dynamics by representing (part of) real stock markets. Since there is a large variety of real stock markets with several partially observable elements and hidden processes, artificial markets differ

  6. CO2 Clamping, Peripheral and Central Fatigue during Hypoxic Knee Extensions in Men.

    Science.gov (United States)

    Rupp, Thomas; Mallouf, Thibault Le Roux; Perrey, Stéphane; Wuyam, Bernard; Millet, Guillaume Y; Verges, Samuel

    2015-12-01

    The central nervous system can play a critical role in limiting exercise performance during hypoxic conditions. Hypocapnia, which is associated with hypoxia-induced hyperventilation, may affect cerebral perfusion. We hypothesized that CO2 clamping during hypoxic isometric knee extensions would improve cerebral oxygenation and reduce central fatigue. Fifteen healthy men (mean ± SD: age, 25 ± 8 yr; body mass, 72 ± 11 kg; height, 179 ± 7 cm) performed intermittent isometric knee extensions at ∼50% of maximal voluntary contraction to task failure in normoxia, hypoxia with CO2 clamping (arterial O2 saturation, 80% ± 2%; end-tidal CO2 partial pressure, 40 ± 2 mm Hg), and hypoxia without CO2 clamping (arterial O2 saturation, 80% ± 3%). Transcranial magnetic stimulation and femoral nerve electrical stimulation were used to assess central and peripheral determinants of fatigue. Prefrontal cortex and quadriceps femoris oxygenation were monitored by multichannel near-infrared spectroscopy. Exercise duration was reduced to a similar extent in hypoxia with CO2 clamping (997 ± 460 s) or hypoxia without CO2 clamping (929 ± 412 s) compared to normoxia (1473 ± 876 s; P stimulation maximal voluntary activation decreased to a greater extent at task failure in hypoxia without CO2 clamping (-18% ± 8%) compared to hypoxia with CO2 clamping (-9% ± 9%; P < 0.01) and normoxia (-10% ± 7%; P < 0.05). Conversely, exercise-induced peripheral fatigue was larger in hypoxia with CO2 clamping than in hypoxia without CO2 clamping (e.g., Db10-to-Db100 ratio of 0.54 ± 0.12 and 0.63 ± 0.11 at task failure, respectively; P < 0.05). The results demonstrate that CO2 clamping can alter central and peripheral mechanisms that contribute to neuromuscular fatigue during hypoxic isometric knee extensions in men. Hypocapnia impairs cerebral oxygenation and central drive but exerts a protective effect against fatigability in muscles.

  7. Artificial Disc Replacement

    Science.gov (United States)

    ... Spondylolisthesis BLOG FIND A SPECIALIST Treatments Artificial Disc Replacement (ADR) Patient Education Committee Jamie Baisden The disc ... Disc An artificial disc (also called a disc replacement, disc prosthesis or spine arthroplasty device) is a ...

  8. Trends in Artificial Intelligence.

    Science.gov (United States)

    Hayes, Patrick

    1978-01-01

    Discusses the foundations of artificial intelligence as a science and the types of answers that may be given to the question, "What is intelligence?" The paradigms of artificial intelligence and general systems theory are compared. (Author/VT)

  9. Artificial Hydration and Nutrition

    Science.gov (United States)

    ... Crisis Situations Pets and Animals myhealthfinder Food and Nutrition Healthy Food Choices Weight Loss and Diet Plans ... Your Health Resources Healthcare Management Artificial Hydration and Nutrition Artificial Hydration and Nutrition Share Print Patients who ...

  10. Artificial Intelligence and Expert Systems.

    Science.gov (United States)

    Lawlor, Joseph

    Artificial intelligence (AI) is the field of scientific inquiry concerned with designing machine systems that can simulate human mental processes. The field draws upon theoretical constructs from a wide variety of disciplines, including mathematics, psychology, linguistics, neurophysiology, computer science, and electronic engineering. Some of the…

  11. Hybrid Applications Of Artificial Intelligence

    Science.gov (United States)

    Borchardt, Gary C.

    1988-01-01

    STAR, Simple Tool for Automated Reasoning, is interactive, interpreted programming language for development and operation of artificial-intelligence application systems. Couples symbolic processing with compiled-language functions and data structures. Written in C language and currently available in UNIX version (NPO-16832), and VMS version (NPO-16965).

  12. Artificial intelligence in hematology.

    Science.gov (United States)

    Zini, Gina

    2005-10-01

    Artificial intelligence (AI) is a computer based science which aims to simulate human brain faculties using a computational system. A brief history of this new science goes from the creation of the first artificial neuron in 1943 to the first artificial neural network application to genetic algorithms. The potential for a similar technology in medicine has immediately been identified by scientists and researchers. The possibility to store and process all medical knowledge has made this technology very attractive to assist or even surpass clinicians in reaching a diagnosis. Applications of AI in medicine include devices applied to clinical diagnosis in neurology and cardiopulmonary diseases, as well as the use of expert or knowledge-based systems in routine clinical use for diagnosis, therapeutic management and for prognostic evaluation. Biological applications include genome sequencing or DNA gene expression microarrays, modeling gene networks, analysis and clustering of gene expression data, pattern recognition in DNA and proteins, protein structure prediction. In the field of hematology the first devices based on AI have been applied to the routine laboratory data management. New tools concern the differential diagnosis in specific diseases such as anemias, thalassemias and leukemias, based on neural networks trained with data from peripheral blood analysis. A revolution in cancer diagnosis, including the diagnosis of hematological malignancies, has been the introduction of the first microarray based and bioinformatic approach for molecular diagnosis: a systematic approach based on the monitoring of simultaneous expression of thousands of genes using DNA microarray, independently of previous biological knowledge, analysed using AI devices. Using gene profiling, the traditional diagnostic pathways move from clinical to molecular based diagnostic systems.

  13. Computer automation and artificial intelligence

    International Nuclear Information System (INIS)

    Hasnain, S.B.

    1992-01-01

    Rapid advances in computing, resulting from micro chip revolution has increased its application manifold particularly for computer automation. Yet the level of automation available, has limited its application to more complex and dynamic systems which require an intelligent computer control. In this paper a review of Artificial intelligence techniques used to augment automation is presented. The current sequential processing approach usually adopted in artificial intelligence has succeeded in emulating the symbolic processing part of intelligence, but the processing power required to get more elusive aspects of intelligence leads towards parallel processing. An overview of parallel processing with emphasis on transputer is also provided. A Fuzzy knowledge based controller for amination drug delivery in muscle relaxant anesthesia on transputer is described. 4 figs. (author)

  14. Effects of Delayed Umbilical Cord Clamping vs Early Clamping on Anemia in Infants at 8 and 12 Months: A Randomized Clinical Trial.

    Science.gov (United States)

    Kc, Ashish; Rana, Nisha; Målqvist, Mats; Jarawka Ranneberg, Linda; Subedi, Kalpana; Andersson, Ola

    2017-03-01

    Delayed umbilical cord clamping has been shown to improve iron stores in infants to 6 months of age. However, delayed cord clamping has not been shown to prevent iron deficiency or anemia after 6 months of age. To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on hemoglobin and ferritin levels at 8 and 12 months of age in infants at high risk for iron deficiency anemia. This randomized clinical trial included 540 late preterm and term infants born vaginally at a tertiary hospital in Kathmandu, Nepal, from October 2 to November 21, 2014. Follow-up included blood levels of hemoglobin and ferritin at 8 and 12 months of age. Follow-up was completed on December 11, 2015. Analysis was based on intention to treat. Infants were randomized to delayed umbilical cord clamping (≥180 seconds after delivery) or early clamping (≤60 seconds after delivery). Main outcomes included hemoglobin and anemia levels at 8 months of age with the power estimate based on the prevalence of anemia. Secondary outcomes included hemoglobin and anemia levels at 12 months of age and ferritin level, iron deficiency, and iron deficiency anemia at 8 and 12 months of age. In this study of 540 infants (281 boys [52.0%] and 259 girls [48.0%]; mean [SD] gestational age, 39.2 [1.1] weeks), 270 each were randomized to the delayed and early clamping groups. At 8 months of age, 212 infants (78.5%) from the delayed group and 188 (69.6%) from the early clamping group returned for blood sampling. After multiple imputation analysis, infants undergoing delayed clamping had higher levels of hemoglobin (10.4 vs 10.2 g/dL; difference, 0.2 g/dL; 95% CI, 0.1 to 0.4 g/dL). Delayed cord clamping also reduced the prevalence of anemia (hemoglobin level infants (relative risk, 0.89; 95% CI, 0.81-0.98; number needed to treat [NNT], 11; 95% CI, 6-54). At 8 months, the risk for iron deficiency was reduced in the delayed clamping group in 60 (22.2%) vs 103 (38.1%) patients

  15. Artificial life and Piaget.

    Science.gov (United States)

    Mueller, Ulrich; Grobman, K H.

    2003-04-01

    Artificial life provides important theoretical and methodological tools for the investigation of Piaget's developmental theory. This new method uses artificial neural networks to simulate living phenomena in a computer. A recent study by Parisi and Schlesinger suggests that artificial life might reinvigorate the Piagetian framework. We contrast artificial life with traditional cognitivist approaches, discuss the role of innateness in development, and examine the relation between physiological and psychological explanations of intelligent behaviour.

  16. A programmable artificial retina

    International Nuclear Information System (INIS)

    Bernard, T.M.; Zavidovique, B.Y.; Devos, F.J.

    1993-01-01

    An artificial retina is a device that intimately associates an imager with processing facilities on a monolithic circuit. Yet, except for simple environments and applications, analog hardware will not suffice to process and compact the raw image flow from the photosensitive array. To solve this output problem, an on-chip array of bare Boolean processors with halftoning facilities might be used, providing versatility from programmability. By setting the pixel memory size to 3 b, the authors have demonstrated both the technological practicality and the computational efficiency of this programmable Boolean retina concept. Using semi-static shifting structures together with some interaction circuitry, a minimal retina Boolean processor can be built with less than 30 transistors and controlled by as few as 6 global clock signals. The successful design, integration, and test of such a 65x76 Boolean retina on a 50-mm 2 CMOS 2-μm circuit are presented

  17. artificial neural network (ann)

    African Journals Online (AJOL)

    2004-08-18

    Aug 18, 2004 ... forecasting models and artificial intelligence techniques and have become one of the major research fields (Kher and Joshin, 2003). (a) Artificial Neural Network and Electrical Load. Prediction. Neural network analysis is an Artificial Intelligence. (AI) approach to mathematical modeling. Neural. Networks ...

  18. Status and headway of the clinical application of artificial ligaments

    Directory of Open Access Journals (Sweden)

    Tianwu Chen

    2015-01-01

    Full Text Available The authors first reviewed the history of clinical application of artificial ligaments. Then, the status of clinical application of artificial ligaments was detailed. Some artificial ligaments possessed comparable efficacy to, and fewer postoperative complications than, allografts and autografts in ligament reconstruction, especially for the anterior cruciate ligament. At the end, the authors focused on the development of two types of artificial ligaments: polyethylene glycol terephthalate artificial ligaments and tissue-engineered ligaments. In conclusion, owing to the advancements in surgical techniques, materials processing, and weaving methods, clinical application of some artificial ligaments so far has demonstrated good outcomes and will become a trend in the future.

  19. Status and headway of the clinical application of artificial ligaments.

    Science.gov (United States)

    Chen, Tianwu; Jiang, Jia; Chen, Shiyi

    2015-01-01

    The authors first reviewed the history of clinical application of artificial ligaments. Then, the status of clinical application of artificial ligaments was detailed. Some artificial ligaments possessed comparable efficacy to, and fewer postoperative complications than, allografts and autografts in ligament reconstruction, especially for the anterior cruciate ligament. At the end, the authors focused on the development of two types of artificial ligaments: polyethylene glycol terephthalate artificial ligaments and tissue-engineered ligaments. In conclusion, owing to the advancements in surgical techniques, materials processing, and weaving methods, clinical application of some artificial ligaments so far has demonstrated good outcomes and will become a trend in the future.

  20. Analysis and Experiments on Sea Load and Fastened Mechanics on Pipe Clamps

    Directory of Open Access Journals (Sweden)

    Wang Zhuo

    2017-08-01

    Full Text Available When an offshore oil field completed and put into production, new subsea pipelines and the new cable need to be established. Cable protection pipe clamp is used to fix cable protection pipe on the jacket. In order to avoid the problem of traditional steel structure clamp splice, counterpoint, fastening difficulty when installed cable protection pipe under water, reduce the risk and workload of under water, This paper develop a new type of portable connecting riser clamp -“backpack clamp” which solve the riser cable protection pipe difficult underwater installation problem. The main structure of backpack clamp used three valves type structure. The load characteristic of a clamping device was determined by the Morison equation which was a classical theory. Clamp device underwater mechanics analysis model was established. The minimum tension pre-tightening force was determined. The results show that the strength of the base meets the requirements after strength analysis with finite element analysis method, stability and strength experiments, which means the clamp based on resin matrix composite is feasible.

  1. Dynamic assembly of Hda and the sliding clamp in the regulation of replication licensing.

    Science.gov (United States)

    Kim, Jin S; Nanfara, Michael T; Chodavarapu, Sundari; Jin, Kyeong S; Babu, Vignesh M P; Ghazy, Mohamed A; Chung, Scisung; Kaguni, Jon M; Sutton, Mark D; Cho, Yunje

    2017-04-20

    Regulatory inactivation of DnaA (RIDA) is one of the major regulatory mechanisms of prokaryotic replication licensing. In RIDA, the Hda-sliding clamp complex loaded onto DNA directly interacts with adenosine triphosphate (ATP)-bound DnaA and stimulates the hydrolysis of ATP to inactivate DnaA. A prediction is that the activity of Hda is tightly controlled to ensure that replication initiation occurs only once per cell cycle. Here, we determined the crystal structure of the Hda-β clamp complex. This complex contains two pairs of Hda dimers sandwiched between two β clamp rings to form an octamer that is stabilized by three discrete interfaces. Two separate surfaces of Hda make contact with the β clamp, which is essential for Hda function in RIDA. The third interface between Hda monomers occludes the active site arginine finger, blocking its access to DnaA. Taken together, our structural and mutational analyses of the Hda-β clamp complex indicate that the interaction of the β clamp with Hda controls the ability of Hda to interact with DnaA. In the octameric Hda-β clamp complex, the inability of Hda to interact with DnaA is a novel mechanism that may regulate Hda function. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. Generalization of the dynamic clamp concept in neurophysiology and behavior.

    Directory of Open Access Journals (Sweden)

    Pablo Chamorro

    Full Text Available The idea of closed-loop interaction in in vitro and in vivo electrophysiology has been successfully implemented in the dynamic clamp concept strongly impacting the research of membrane and synaptic properties of neurons. In this paper we show that this concept can be easily generalized to build other kinds of closed-loop protocols beyond (or in addition to electrical stimulation and recording in neurophysiology and behavioral studies for neuroethology. In particular, we illustrate three different examples of goal-driven real-time closed-loop interactions with drug microinjectors, mechanical devices and video event driven stimulation. Modern activity-dependent stimulation protocols can be used to reveal dynamics (otherwise hidden under traditional stimulation techniques, achieve control of natural and pathological states, induce learning, bridge between disparate levels of analysis and for a further automation of experiments. We argue that closed-loop interaction calls for novel real time analysis, prediction and control tools and a new perspective for designing stimulus-response experiments, which can have a large impact in neuroscience research.

  3. Impedance spectra of patch clamp scenarios for single cells immobilized on a lab-on-a-chip

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

    2014-01-01

    A simple method based on impedance spectroscopy (IS) was developed to distinguish between different patch clamp modes for single cells trapped on microapertures in a patch clamp microchannel array designed for patch clamping on cultured cells. The method allows detecting via impedance analysis wh...

  4. A Central Swivel Point in the RFC Clamp Loader Controls PCNA Opening and Loading on DNA

    OpenAIRE

    Sakato, Miho; O’Donnell, Mike; Hingorani, Manju M.

    2011-01-01

    Replication Factor C (RFC) is a 5-subunit complex that loads PCNA clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA+ superfamily, and their ATPase activity drives interactions between the clamp loader, clamp, and ptDNA, leading to topologically linked PCNA•ptDNA. We report the kinetics of transient events in S. cerevisiae RFC catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing and PCNA...

  5. A Triboelectric-Based Artificial Basilar Membrane to Mimic Cochlear Tonotopy.

    Science.gov (United States)

    Jang, Jongmoon; Lee, JangWoo; Jang, Jeong Hun; Choi, Hongsoo

    2016-10-01

    A triboelectric-based artificial basilar membrane (TEABM) can mimic cochlear tonotopy by triboelectrification between Kapton film and aluminum foil. The two films are stacked and clamped to form a beam structure. The TEABM tonotopy is tested using an animal model to verify the feasibility of a self-powered acoustic sensor for a prototype cochlear implant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. What Artificial Intelligence Is Doing for Training.

    Science.gov (United States)

    Kirrane, Peter R.; Kirrane, Diane E.

    1989-01-01

    Discusses the three areas of research and application of artificial intelligence: (1) robotics, (2) natural language processing, and (3) knowledge-based or expert systems. Focuses on what expert systems can do, especially in the area of training. (JOW)

  7. Artificially Engineered Protein Polymers.

    Science.gov (United States)

    Yang, Yun Jung; Holmberg, Angela L; Olsen, Bradley D

    2017-06-07

    Modern polymer science increasingly requires precise control over macromolecular structure and properties for engineering advanced materials and biomedical systems. The application of biological processes to design and synthesize artificial protein polymers offers a means for furthering macromolecular tunability, enabling polymers with dispersities of ∼1.0 and monomer-level sequence control. Taking inspiration from materials evolved in nature, scientists have created modular building blocks with simplified monomer sequences that replicate the function of natural systems. The corresponding protein engineering toolbox has enabled the systematic development of complex functional polymeric materials across areas as diverse as adhesives, responsive polymers, and medical materials. This review discusses the natural proteins that have inspired the development of key building blocks for protein polymer engineering and the function of these elements in material design. The prospects and progress for scalable commercialization of protein polymers are reviewed, discussing both technology needs and opportunities.

  8. Modeling the euglycemic hyperinsulinemic clamp by stochastic differential equations.

    Science.gov (United States)

    Picchini, Umberto; Ditlevsen, Susanne; De Gaetano, Andrea

    2006-11-01

    The Euglycemic Hyperinsulinemic Clamp (EHC) is the most widely used experimental procedure for the determination of insulin sensitivity. In the present study, 16 subjects with BMI between 18.5 and 63.6 kg/m(2) have been studied with a long-duration (5 hours) EHC. In order to explain the oscillations of glycemia occurring in response to the hyperinsulinization and to the continuous glucose infusion at varying speeds, we first hypothesized a system of ordinary differential equations (ODEs), with limited success. We then extended the model and represented the experiment using a system of stochastic differential equations (SDEs). The latter allow for distinction between (i) random variation imputable to observation error and (ii) system noise (intrinsic variability of the metabolic system), due to a variety of influences which change over time. The stochastic model of the EHC was fitted to data and the system noise was estimated by means of a (simulated) maximum likelihood procedure, for a series of different hypothetical measurement error values. We showed that, for the whole range of reasonable measurement error values: (i) the system noise estimates are non-negligible; and (ii) these estimates are robust to changes in the likely value of the measurement error. Explicit expression of system noise is physiologically relevant in this case, since glucose uptake rate is known to be affected by a host of additive influences, usually neglected when modeling metabolism. While in some of the studied subjects system noise appeared to only marginally affect the dynamics, in others the system appeared to be driven more by the erratic oscillations in tissue glucose transport rather than by the overall glucose-insulin control system. It is possible that the quantitative relevance of the unexpressed effects (system noise) should be considered in other physiological situations, represented so far only with deterministic models.

  9. Reinforcement Learning Based Artificial Immune Classifier

    Directory of Open Access Journals (Sweden)

    Mehmet Karakose

    2013-01-01

    Full Text Available One of the widely used methods for classification that is a decision-making process is artificial immune systems. Artificial immune systems based on natural immunity system can be successfully applied for classification, optimization, recognition, and learning in real-world problems. In this study, a reinforcement learning based artificial immune classifier is proposed as a new approach. This approach uses reinforcement learning to find better antibody with immune operators. The proposed new approach has many contributions according to other methods in the literature such as effectiveness, less memory cell, high accuracy, speed, and data adaptability. The performance of the proposed approach is demonstrated by simulation and experimental results using real data in Matlab and FPGA. Some benchmark data and remote image data are used for experimental results. The comparative results with supervised/unsupervised based artificial immune system, negative selection classifier, and resource limited artificial immune classifier are given to demonstrate the effectiveness of the proposed new method.

  10. Reinforcement Learning Based Artificial Immune Classifier

    Science.gov (United States)

    Karakose, Mehmet

    2013-01-01

    One of the widely used methods for classification that is a decision-making process is artificial immune systems. Artificial immune systems based on natural immunity system can be successfully applied for classification, optimization, recognition, and learning in real-world problems. In this study, a reinforcement learning based artificial immune classifier is proposed as a new approach. This approach uses reinforcement learning to find better antibody with immune operators. The proposed new approach has many contributions according to other methods in the literature such as effectiveness, less memory cell, high accuracy, speed, and data adaptability. The performance of the proposed approach is demonstrated by simulation and experimental results using real data in Matlab and FPGA. Some benchmark data and remote image data are used for experimental results. The comparative results with supervised/unsupervised based artificial immune system, negative selection classifier, and resource limited artificial immune classifier are given to demonstrate the effectiveness of the proposed new method. PMID:23935424

  11. Prediction of clamp-derived insulin sensitivity from the oral glucose insulin sensitivity index

    DEFF Research Database (Denmark)

    Tura, Andrea; Chemello, Gaetano; Szendroedi, Julia

    2018-01-01

    that underwent both a clamp and an OGTT or meal test, thereby allowing calculation of both the M value and OGIS. The population was divided into a training and a validation cohort (n = 359 and n = 154, respectively). After a stepwise selection approach, the best model for M value prediction was applied......AIMS/HYPOTHESIS: The euglycaemic-hyperinsulinaemic clamp is the gold-standard method for measuring insulin sensitivity, but is less suitable for large clinical trials. Thus, several indices have been developed for evaluating insulin sensitivity from the oral glucose tolerance test (OGTT). However......, most of them yield values different from those obtained by the clamp method. The aim of this study was to develop a new index to predict clamp-derived insulin sensitivity (M value) from the OGTT-derived oral glucose insulin sensitivity index (OGIS). METHODS: We analysed datasets of people...

  12. Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, M H; Andersen, U B; Wachtell, K

    1999-01-01

    hyperinsulinemic clamp in 26 young, healthy subjects and 43 elderly patients with unmedicated essential hypertension and left ventricular hypertrophy. The 3-h Sip correlated strongly with the 2-h M/IG in the patients (r = 0.88, p

  13. Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.

    Science.gov (United States)

    Kullmann, Paul H M; Wheeler, Diek W; Beacom, Joshua; Horn, John P

    2004-01-01

    The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.

  14. Design and testing of CRBRP insulated horizontal and vertical pipe clamps

    International Nuclear Information System (INIS)

    Pollono, L.P.; Mello, R.M.

    1980-01-01

    The Clinch River Breeder Reactor Plant (CRBRP) Primary Heat Transport system piping may be characterized as large-diameter, thin-wall piping which transports liquid sodium at high temperatures. The piping is arranged in accord with the elevated loop concept, consisting of large horizontal inplane, expansion loops and long, vertical runs of piping. These characteristics and the postulated thermal transient and seismic loads, which are imposed on the piping, dictate pipe clamp designs that are substantially different from standard off the shelf pipe clamp designs. The design features of the CRBRP horizontal and vertical pipe clamps for the large sodium piping, the various test programs used to verify the clamp designs, and the results of this testing are presented

  15. Welding scheme optimization for the U-shaped flexible clamps of ITER poloidal field coil supports

    International Nuclear Information System (INIS)

    Zhang Teng; Li Pengyuan; Sun Zhenchao; Xu Dan; Han Shilei; Wang Yue

    2015-01-01

    The numerical simulation and welding experiment were adopted to investigate the welding deformation of ITER poloidal field coil supports, and the comparison of the simulation and the actual measurement was made to verify the validity of simulation. The basic law of welding seam deformation on the U-shaped flexible clamps was obtained and the existing clamps type was improved. Furthermore, based on the verified heat and mechanical boundary condition and the optimization clamp, the calculations of welding deformations of U-shaped flexible clamps in three different welding plans were carried out and an optimized plan for the poloidal field coil supports fabricating was proposed. The optimal welding deformation is controlled within 0.6 mm. (authors)

  16. Suppression of Spiral Waves by Voltage Clamp Techniques in a Conductance-Based Cardiac Tissue Model

    International Nuclear Information System (INIS)

    Lian-Chun, Yu; Guo-Yong, Zhang; Yong, Chen; Jun, Ma

    2008-01-01

    A new control method is proposed to control the spatio-temporal dynamics in excitable media, which is described by the Morris–Lecar cells model. It is confirmed that successful suppression of spiral waves can be obtained by spatially clamping the membrane voltage of the excitable cells. The low voltage clamping induces breakup of spiral waves and the fragments are soon absorbed by low voltage obstacles, whereas the high voltage clamping generates travel waves that annihilate spiral waves through collision with them. However, each method has its shortcomings. Furthermore, a two-step method that combines both low and high voltage clamp techniques is then presented as a possible way of out this predicament. (cross-disciplinary physics and related areas of science and technology)

  17. Model Clamp: A Computer Tool to Probe Action Potential Transfer Between Cardiac Cells

    National Research Council Canada - National Science Library

    Wilders, Ronald

    2001-01-01

    In the early nineties, Joyner and coworkers introduced the "coupling clamp" technique in which an isolated cardiac cell can be electrically coupled to either another isolated cardiac cell or to an analog model cell (RC circuit...

  18. Two unique ligand-binding clamps of Rhizopus oryzae starch binding domain for helical structure disruption of amylose.

    Directory of Open Access Journals (Sweden)

    Ting-Ying Jiang

    Full Text Available The N-terminal starch binding domain of Rhizopus oryzae glucoamylase (RoSBD has a high binding affinity for raw starch. RoSBD has two ligand-binding sites, each containing a ligand-binding clamp: a polyN clamp residing near binding site I is unique in that it is expressed in only three members of carbohydrate binding module family 21 (CBM21 members, and a Y32/F58 clamp located at binding site II is conserved in several CBMs. Here we characterized different roles of these sites in the binding of insoluble and soluble starches using an amylose-iodine complex assay, atomic force microscopy, isothermal titration calorimetry, site-directed mutagenesis, and structural bioinformatics. RoSBD induced the release of iodine from the amylose helical cavity and disrupted the helical structure of amylose type III, thereby significantly diminishing the thickness and length of the amylose type III fibrils. A point mutation in the critical ligand-binding residues of sites I and II, however, reduced both the binding affinity and amylose helix disruption. This is the first molecular model for structure disruption of the amylose helix by a non-hydrolytic CBM21 member. RoSBD apparently twists the helical amylose strands apart to expose more ligand surface for further SBD binding. Repeating the process triggers the relaxation and unwinding of amylose helices to generate thinner and shorter amylose fibrils, which are more susceptible to hydrolysis by glucoamylase. This model aids in understanding the natural roles of CBMs in protein-glycan interactions and contributes to potential molecular engineering of CBMs.

  19. Two Unique Ligand-Binding Clamps of Rhizopus oryzae Starch Binding Domain for Helical Structure Disruption of Amylose

    Science.gov (United States)

    Jiang, Ting-Ying; Ci, Yuan-Pei; Chou, Wei-I; Lee, Yuan-Chuan; Sun, Yuh-Ju; Chou, Wei-Yao; Li, Kun-Mou; Chang, Margaret Dah-Tsyr

    2012-01-01

    The N-terminal starch binding domain of Rhizopus oryzae glucoamylase (RoSBD) has a high binding affinity for raw starch. RoSBD has two ligand-binding sites, each containing a ligand-binding clamp: a polyN clamp residing near binding site I is unique in that it is expressed in only three members of carbohydrate binding module family 21 (CBM21) members, and a Y32/F58 clamp located at binding site II is conserved in several CBMs. Here we characterized different roles of these sites in the binding of insoluble and soluble starches using an amylose-iodine complex assay, atomic force microscopy, isothermal titration calorimetry, site-directed mutagenesis, and structural bioinformatics. RoSBD induced the release of iodine from the amylose helical cavity and disrupted the helical structure of amylose type III, thereby significantly diminishing the thickness and length of the amylose type III fibrils. A point mutation in the critical ligand-binding residues of sites I and II, however, reduced both the binding affinity and amylose helix disruption. This is the first molecular model for structure disruption of the amylose helix by a non-hydrolytic CBM21 member. RoSBD apparently twists the helical amylose strands apart to expose more ligand surface for further SBD binding. Repeating the process triggers the relaxation and unwinding of amylose helices to generate thinner and shorter amylose fibrils, which are more susceptible to hydrolysis by glucoamylase. This model aids in understanding the natural roles of CBMs in protein-glycan interactions and contributes to potential molecular engineering of CBMs. PMID:22815939

  20. Delayed umbilical cord clamping after childbirth: potential benefits to baby's health

    Directory of Open Access Journals (Sweden)

    Uwins C

    2014-11-01

    Full Text Available Christina Uwins,1 David JR Hutchon2 1Department of Obstetrics and Gynaecology, Croydon University Hospital, Croydon, 2Department of Obstetrics, Darlington Memorial Hospital, Darlington, UKAbstract: Early cord clamping was initially introduced as part of the package of care known as “active management of the third stage”, which was implemented to reduce postpartum hemorrhage. It has now been shown to provide no benefit to the mother and to result in harm to the neonate. The clinical trial evidence relating to delayed cord clamping compared to immediate cord clamping is presented and the physiological rationale for delayed cord clamping is discussed in this paper. Most organizations (eg World Health Organization (WHO, Royal College of Obstetricians and Gynaecologists (RCOG, Resuscitation Council (UK,The International Federation of Gynecology and Obstetrics (FIGO, International Confederation of Midwives, International Liaison Committee on Resuscitation (ILCOR and the European Resuscitation Council now advise a delay of 1–3 minutes before clamping the cord in term and preterm infants, and clinicians need to be aware of this change. Healthy neonates benefit from a more physiological and gentle transition from placental to pulmonary respiration, and we explain why this benefit should be provided to all neonates until there is any evidence to the contrary. The harm of early cord clamping is not limited to anemia and iron deficiency, and evidence for a wide range of possible harms of early cord clamping is presented. The need for resuscitation is one of the most common concerns, and ways of overcoming these concerns are described.Keywords: transition, cord clamping, hypovolemia, intraventricular hemorrhage

  1. Patch Clamp: A Powerful Technique for Studying the Mechanism of Acupuncture

    Directory of Open Access Journals (Sweden)

    D. Zhang

    2012-01-01

    Full Text Available Cellular and molecular events can be investigated using electrophysiological techniques. In particular, the patch-clamp method provides detailed information. In addition, the patch-clamp technique has become a powerful method for investigating the mechanisms underlying the effects of acupuncture. In this paper, recent researches on how acupuncture might modulate electrophysiological responses in the central nervous system (CNS and affect peripheral structures are reviewed.

  2. Computer Simulation Model to Train Medical Personnel on Glucose Clamp Procedures.

    Science.gov (United States)

    Maghoul, Pooya; Boulet, Benoit; Tardif, Annie; Haidar, Ahmad

    2017-10-01

    A glucose clamp procedure is the most reliable way to quantify insulin pharmacokinetics and pharmacodynamics, but skilled and trained research personnel are required to frequently adjust the glucose infusion rate. A computer environment that simulates glucose clamp experiments can be used for efficient personnel training and development and testing of algorithms for automated glucose clamps. We built 17 virtual healthy subjects (mean age, 25±6 years; mean body mass index, 22.2±3 kg/m 2 ), each comprising a mathematical model of glucose regulation and a unique set of parameters. Each virtual subject simulates plasma glucose and insulin concentrations in response to intravenous insulin and glucose infusions. Each virtual subject provides a unique response, and its parameters were estimated from combined intravenous glucose tolerance test-hyperinsulinemic-euglycemic clamp data using the Bayesian approach. The virtual subjects were validated by comparing their simulated predictions against data from 12 healthy individuals who underwent a hyperglycemic glucose clamp procedure. Plasma glucose and insulin concentrations were predicted by the virtual subjects in response to glucose infusions determined by a trained research staff performing a simulated hyperglycemic clamp experiment. The total amount of glucose infusion was indifferent between the simulated and the real subjects (85±18 g vs. 83±23 g; p=NS) as well as plasma insulin levels (63±20 mU/L vs. 58±16 mU/L; p=NS). The virtual subjects can reliably predict glucose needs and plasma insulin profiles during hyperglycemic glucose clamp conditions. These virtual subjects can be used to train personnel to make glucose infusion adjustments during clamp experiments. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

  3. Dual Roles of Ctf18-RFC: Loading the Clamp and Angling for the Polymerase.

    Science.gov (United States)

    Pellegrini, Luca

    2018-01-02

    Clamp loaders such as Ctf18-RFC assist DNA replication by loading the PCNA clamp onto DNA. In this issue of Structure, Grabarczyk et al. (2018) reveal that a hook-like structure formed by the unique Dcc1 and Ctf8 subunits mediates the interaction of Ctf18-RFC with the leading strand DNA polymerase ɛ. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. The TCF C-clamp DNA binding domain expands the Wnt transcriptome via alternative target recognition.

    Science.gov (United States)

    Hoverter, Nate P; Zeller, Michael D; McQuade, Miriam M; Garibaldi, Angela; Busch, Anke; Selwan, Elizabeth M; Hertel, Klemens J; Baldi, Pierre; Waterman, Marian L

    2014-12-16

    LEF/TCFs direct the final step in Wnt/β-catenin signalling by recruiting β-catenin to genes for activation of transcription. Ancient, non-vertebrate TCFs contain two DNA binding domains, a High Mobility Group box for recognition of the Wnt Response Element (WRE; 5'-CTTTGWWS-3') and the C-clamp domain for recognition of the GC-rich Helper motif (5'-RCCGCC-3'). Two vertebrate TCFs (TCF-1/TCF7 and TCF-4/TCF7L2) use the C-clamp as an alternatively spliced domain to regulate cell-cycle progression, but how the C-clamp influences TCF binding and activity genome-wide is not known. Here, we used a doxycycline inducible system with ChIP-seq to assess how the C-clamp influences human TCF1 binding genome-wide. Metabolic pulse-labeling of nascent RNA with 4'Thiouridine was used with RNA-seq to connect binding to the Wnt transcriptome. We find that the C-clamp enables targeting to a greater number of gene loci for stronger occupancy and transcription regulation. The C-clamp uses Helper sites concurrently with WREs for gene targeting, but it also targets TCF1 to sites that do not have readily identifiable canonical WREs. The coupled ChIP-seq/4'Thiouridine-seq analysis identified new Wnt target genes, including additional regulators of cell proliferation. Thus, C-clamp containing isoforms of TCFs are potent transcriptional regulators with an expanded transcriptome directed by C-clamp-Helper site interactions. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  5. An ANN Based Capicitor Voltage Balancing Method For Neutral Point Clamped Multi-Level Inverter

    OpenAIRE

    P.J.S. Praveen,; Narendra Bavisetti

    2015-01-01

    Multi-level inverters are became popular for usage in medium voltage, low voltage power applications due to flexibility in control and better performance characteristics in terms of harmonic regulation. Neutral point clamped are popular as they require less number of sources as their input when compared with their counter parts i.e. cascaded multi-level inverters and found to be reliable when compared with flying capacitor based multi-level inverters. But when neutral clamped tech...

  6. Artificial Astrocytes Improve Neural Network Performance

    Science.gov (United States)

    Porto-Pazos, Ana B.; Veiguela, Noha; Mesejo, Pablo; Navarrete, Marta; Alvarellos, Alberto; Ibáñez, Oscar; Pazos, Alejandro; Araque, Alfonso

    2011-01-01

    Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN) and artificial neuron-glia networks (NGN) to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function. PMID:21526157

  7. Artificial astrocytes improve neural network performance.

    Directory of Open Access Journals (Sweden)

    Ana B Porto-Pazos

    Full Text Available Compelling evidence indicates the existence of bidirectional communication between astrocytes and neurons. Astrocytes, a type of glial cells classically considered to be passive supportive cells, have been recently demonstrated to be actively involved in the processing and regulation of synaptic information, suggesting that brain function arises from the activity of neuron-glia networks. However, the actual impact of astrocytes in neural network function is largely unknown and its application in artificial intelligence remains untested. We have investigated the consequences of including artificial astrocytes, which present the biologically defined properties involved in astrocyte-neuron communication, on artificial neural network performance. Using connectionist systems and evolutionary algorithms, we have compared the performance of artificial neural networks (NN and artificial neuron-glia networks (NGN to solve classification problems. We show that the degree of success of NGN is superior to NN. Analysis of performances of NN with different number of neurons or different architectures indicate that the effects of NGN cannot be accounted for an increased number of network elements, but rather they are specifically due to astrocytes. Furthermore, the relative efficacy of NGN vs. NN increases as the complexity of the network increases. These results indicate that artificial astrocytes improve neural network performance, and established the concept of Artificial Neuron-Glia Networks, which represents a novel concept in Artificial Intelligence with implications in computational science as well as in the understanding of brain function.

  8. Artificial Intelligence in Astronomy

    Science.gov (United States)

    Devinney, E. J.; Prša, A.; Guinan, E. F.; Degeorge, M.

    2010-12-01

    From the perspective (and bias) as Eclipsing Binary researchers, we give a brief overview of the development of Artificial Intelligence (AI) applications, describe major application areas of AI in astronomy, and illustrate the power of an AI approach in an application developed under the EBAI (Eclipsing Binaries via Artificial Intelligence) project, which employs Artificial Neural Network technology for estimating light curve solution parameters of eclipsing binary systems.

  9. Quo Vadis, Artificial Intelligence?

    OpenAIRE

    Berrar, Daniel; Sato, Naoyuki; Schuster, Alfons

    2010-01-01

    Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervou...

  10. Artificial cognition architectures

    CERN Document Server

    Crowder, James A; Friess, Shelli A

    2013-01-01

    The goal of this book is to establish the foundation, principles, theory, and concepts that are the backbone of real, autonomous Artificial Intelligence. Presented here are some basic human intelligence concepts framed for Artificial Intelligence systems. These include concepts like Metacognition and Metamemory, along with architectural constructs for Artificial Intelligence versions of human brain functions like the prefrontal cortex. Also presented are possible hardware and software architectures that lend themselves to learning, reasoning, and self-evolution

  11. Locoregional Anesthesia for Carotid Endarterectomy: Identification of Patients with Intolerance to Cross-Clamping.

    Science.gov (United States)

    Dellaretti, Marcos; de Vasconcelos, Laura T; Dourado, Jules; de Souza, Renata F; Fontoura, Renato R; de Sousa, Atos A

    2016-03-01

    During carotid endarterectomy (CEA), carotid cross-clamping is performed to allow for artery incision and plaque removal. A small subgroup of patients can tolerate carotid occlusion for only a few seconds, if at all, without presenting neurologic deficit. These patients are described as having ''cross-clamp intolerance.'' The purpose of this study was to demonstrate the safety of locoregional anesthesia in identifying patients with cross-clamp intolerance and factors associated with this condition. From August 2008 to May 2010, 115 consecutive patients were submitted to CEA under locoregional anesthesia at the Santa Casa de Belo Horizonte; the procedure was performed by the main author. Patients who showed intolerance to internal carotid artery (ICA) occlusion for intolerance. Among the 115 participating patients, 9.6% (11 patients) showed intolerance to ICA occlusion and developed deficits in intolerance). The factor that was associated with cross-clamp intolerance was the mean degree of contralateral carotid stenosis, which was 57.5% for those who presented intolerance and 27.8% for those who tolerated ICA occlusion. Locoregional anesthesia is a safe method for identifying patients with cross-clamp intolerance. Patients with cross-clamp intolerance present contralateral stenosis that is greater on average than patients who readily tolerate carotid artery occlusion. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The effect of clamping a tensioned wire: implications for the Ilizarov external fixation system.

    Science.gov (United States)

    Watson, M A; Mathias, K J; Maffulli, N; Hukins, D W L

    2003-01-01

    This study demonstrates that clamping a tensioned wire can cause a reduction in wire tension. Tension (about 1275 N) was applied to a wire that was subsequently clamped, using cannulated bolts, to the steel half-ring of an Ilizarov external fixator. The tension in the wire was monitored before, during and after clamping. The apparatus was disassembled and the deformations in the wire caused by the clamps were measured. This experiment was repeated 15 times. When the wire was clamped to the frame, the wire tension was reduced by 22 +/- 7 per cent (mean +/- standard deviation, SD). The drop in wire tension was linearly correlated (r = 0.96; p toothpaste from a tube) and so reduce its tension during fixator assembly. To assess the magnitude of this effect in the clinical situation, the FE model analysis was repeated to replicate clamping a 1.8-mm-diameter wire to a 180-mm-diameter steel Ilizarov ring component. The analysis showed that for these conditions the tension reduced by 8-29 per cent. The results of this study highlight a general engineering problem: how can a tensioned wire be secured to a structure without an appreciable loss of tension? If the performance of the structure depends on the wire tension, this performance will change when the wire is secured.

  13. Patch-clamp technique to characterize ion channels in enlarged individual endolysosomes.

    Science.gov (United States)

    Chen, Cheng-Chang; Cang, Chunlei; Fenske, Stefanie; Butz, Elisabeth; Chao, Yu-Kai; Biel, Martin; Ren, Dejian; Wahl-Schott, Christian; Grimm, Christian

    2017-08-01

    According to proteomics analyses, more than 70 different ion channels and transporters are harbored in membranes of intracellular compartments such as endosomes and lysosomes. Malfunctioning of these channels has been implicated in human diseases such as lysosomal storage disorders, neurodegenerative diseases and metabolic pathologies, as well as in the progression of certain infectious diseases. As a consequence, these channels have engendered very high interest as future drug targets. Detailed electrophysiological characterization of intracellular ion channels is lacking, mainly because standard methods to analyze plasma membrane ion channels, such as the patch-clamp technique, are not readily applicable to intracellular organelles. Here we present a protocol detailing how to implement a manual patch-clamp technique for endolysosomal compartments. In contrast to the alternatively used planar endolysosomal patch-clamp technique, this method is a visually controlled, direct patch-clamp technique similar to conventional patch-clamping. The protocol assumes basic knowledge and experience with patch-clamp methods. Implementation of the method requires up to 1 week, and material preparation takes ∼2-4 d. An individual experiment (i.e., measurement of channel currents across the endolysosomal membrane), including control experiments, can be completed within 1 h. This excludes the time for endolysosome enlargement, which takes between 1 and 48 h, depending on the approach and cell type used. Data analysis requires an additional hour.

  14. Early identification of hERG liability in drug discovery programs by automated patch clamp.

    Science.gov (United States)

    Danker, Timm; Möller, Clemens

    2014-01-01

    Blockade of the cardiac ion channel coded by human ether-à-gogo-related gene (hERG) can lead to cardiac arrhythmia, which has become a major concern in drug discovery and development. Automated electrophysiological patch clamp allows assessment of hERG channel effects early in drug development to aid medicinal chemistry programs and has become routine in pharmaceutical companies. However, a number of potential sources of errors in setting up hERG channel assays by automated patch clamp can lead to misinterpretation of data or false effects being reported. This article describes protocols for automated electrophysiology screening of compound effects on the hERG channel current. Protocol details and the translation of criteria known from manual patch clamp experiments to automated patch clamp experiments to achieve good quality data are emphasized. Typical pitfalls and artifacts that may lead to misinterpretation of data are discussed. While this article focuses on hERG channel recordings using the QPatch (Sophion A/S, Copenhagen, Denmark) technology, many of the assay and protocol details given in this article can be transferred for setting up different ion channel assays by automated patch clamp and are similar on other planar patch clamp platforms.

  15. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  16. An artificial muscle computer

    Science.gov (United States)

    Marc O'Brien, Benjamin; Alexander Anderson, Iain

    2013-03-01

    We have built an artificial muscle computer based on Wolfram's "2, 3" Turing machine architecture, the simplest known universal Turing machine. Our computer uses artificial muscles for its instruction set, output buffers, and memory write and addressing mechanisms. The computer is very slow and large (0.15 Hz, ˜1 m3); however by using only 13 artificial muscle relays, it is capable of solving any computable problem given sufficient memory, time, and reliability. The development of this computer shows that artificial muscles can think—paving the way for soft robots with reflexes like those seen in nature.

  17. Quantification of atmospheric emissions and energy metrics from simulated clamp kiln technology in the clay brick industry.

    Science.gov (United States)

    Akinshipe, Oladapo; Kornelius, Gerrit

    2018-05-01

    The quantification of atmospheric emissions from clamp kilns in the clay brick industry has met with limited success globally. The complex configuration of clamp kilns using coal or other carbonaceous fuels and uncertainties regarding kiln combustion conditions, has proven to be a hurdle in measurement of emissions and standardization of process and energy metrics. To enable quantification of these metrics, a model kiln was designed to simulate operating conditions and configuration similar to transverse slice of a typical full-scale clamp kiln, but with lower capacity (20,000 to 35,000 bricks per cycle). Hourly measurements of flue gas at extraction duct were recorded for thirteen firing cycles obtained from various source factories, each lasting 8-14 days, for SO 2 , NO 2 , NO, PM, CO and CO 2 emissions in the extraction stack. A statistical mean efficiency for model kiln emissions capturing and channelling capacity was calculated from sulfur mass balance results of batches that lie within 95% confidence interval of assumed true mean (100%) to give 84.2%. Final emission factors (mean ± standard deviation) were quantified as 22.5 ± 18.8 g/brick for CO, 0.14 ± 0.1 g/brick for NO, 0.0 g/brick for NO 2 , 0.14 ± 0.1 g/brick for NO x , 1.07 ± 0.7 g/brick for SO 2 , 378 ± 223 g/brick for CO 2 ; 0.96 ± 0.5 g/brick for PM 10 ; as well as 1.53 g/brick for hydrocarbons. Energy analysis indicate that a significant reduction of 0.9 MJ/kg (36%) in energy use could be achieved by clamp kiln operators, thereby reducing input costs, and significantly reducing atmospheric emissions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Processing semblances induced through inter-postsynaptic functional LINKs, presumed biological parallels of K-lines proposed for building artificial intelligence

    Directory of Open Access Journals (Sweden)

    Kunjumon I Vadakkan

    2011-07-01

    Full Text Available The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of virtual internal sensation - namely, semblion. Neuronal networks that undergo continuous oscillatory activity at certain levels of their organization induce semblions enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI. Suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky’s K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system are explained.

  19. Degradação do pesticida Padron® por processos fotoquímicos utilizando luz artificial e solar Degradation of Padron® by photochemical processes using artificial and sunlight radiation

    Directory of Open Access Journals (Sweden)

    Silvio César Godinho Teixeira

    2007-01-01

    Full Text Available Destruction of Padron® (dye and picloram was evaluated using a photoreactor and a solar reactor. Photolysis was observed using only a germicide lamp (GL. Black light (BL and H2O2 (172 mmol L-1 promoted a conversion of 49% and 6% of dye and picloram, respectively. Photocatalytic processes were more efficient using TiO2/GL (96%-dye; 60%-picloram than TiO2/BL (44%-dye; 40%-picloram. Photolysis using sunlight was not observed during PadronÒ recirculation in the reactor constructed with four borosilicate tubes. Meanwhile, adding H2O2 resulted in 12% conversion of dissolved organic compounds. Finally, the most efficient mineralization (60% was obtained using the Fenton reaction ( H2O2-176 mmol L-1; FeSO4x6H2O-90 mmol L-1 and sunlight.

  20. Chitosan/Fe spheres on the blue QR-19 dye degradation by photo Fenton processes using artificial or solar light; Esferas de quitosana/Fe na degradacao do corante azul QR-19 por processos foto-Fenton utilizando luz artificial ou solar

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Kely V. de; Zamora, Patricio G.P.; Zawadzki, Sonia F. [Universidade Federal do Parana (DQ/UFPR), Curitiba, PR (Brazil). Dept. de Quimica], E-mail: zawadzki@quimica.ufpr.br

    2010-07-15

    The contamination of water resources is one of the greatest environmental problems today. Among the polluting sources are the textile industries due to the production of large volumes of effluent, often treated inefficiently. The main reason for the environmental impact of the rejected materials is the presence of dyes such as azo reactive compounds that can generate by-products with carcinogenic and mutagenic effects. They may also include anthraquinone type compounds, which are highly resistant to degradation and persist in the effluent for a long time. The purpose of this study is the use of photo-Fenton processes assisted by artificial or solar light, using immobilized iron on chitosan beads, crosslinked with glutaraldehyde, for the anthraquinone type compound Blue QR-19 standard dye degradation in aqueous solutions. The obtained spheres showed a regular size and 4.0 mm diameter. The results showed 90% discoloration of the system within 180 minutes and a 60% total organic carbon (TOC)reduction for the photo-Fenton system using artificial light. For the system using sunlight, the total discoloration was achieved in 120 minutes and the TOC value decreased 70%. Also observed was that iron remained in the polymeric matrix after the treatment, thus allowing reuse. (author)

  1. Artificial life and life artificialization in Tron

    Directory of Open Access Journals (Sweden)

    Carolina Dantas Figueiredo

    2012-12-01

    Full Text Available Cinema constantly shows the struggle between the men and artificial intelligences. Fiction, and more specifically fiction films, lends itself to explore possibilities asking “what if?”. “What if”, in this case, is related to the eventual rebellion of artificial intelligences, theme explored in the movies Tron (1982 and Tron Legacy (2010 trat portray the conflict between programs and users. The present paper examines these films, observing particularly the possibility programs empowering. Finally, is briefly mentioned the concept of cyborg as a possibility of response to human concerns.

  2. Gd3+ and calcium sensitive, sodium leak currents are features of weak membrane-glass seals in patch clamp recordings.

    Directory of Open Access Journals (Sweden)

    Adrienne N Boone

    Full Text Available The properties of leaky patch currents in whole cell recording of HEK-293T cells were examined as a means to separate these control currents from expressed sodium and calcium leak channel currents from snail NALCN leak channels possessing both sodium (EKEE and calcium (EEEE selectivity filters. Leak currents were generated by the weakening of gigaohm patch seals by artificial membrane rupture using the ZAP function on the patch clamp amplifier. Surprisingly, we found that leak currents generated from the weakened membrane/glass seal can be surprisingly stable and exhibit behavior that is consistent with a sodium leak current derived from an expressible channel. Leaky patch currents differing by 10 fold in size were similarly reduced in size when external sodium ions were replaced with the large monovalent ion NMDG+. Leaky patch currents increased when external Ca2+ (1.2 mM was lowered to 0.1 mM and were inhibited (>40% to >90% with 10 µM Gd3+, 100 µM La3+, 1 mM Co2+ or 1 mM Cd2+. Leaky patch currents were relatively insensitive (<30% to 1 mM Ni2+ and exhibited a variable amount of block with 1 mM verapamil and were insensitive to 100 µM mibefradil or 100 µM nifedipine. We hypothesize that the rapid changes in leak current size in response to changing external cations or drugs relates to their influences on the membrane seal adherence and the electro-osmotic flow of mobile cations channeling in crevices of a particular pore size in the interface between the negatively charged patch electrode and the lipid membrane. Observed sodium leak conductance currents in weak patch seals are reproducible between the electrode glass interface with cell membranes, artificial lipid or Sylgard rubber.

  3. Artificial insemination in poultry

    Science.gov (United States)

    Artificial insemination is a relative simple yet powerful tool geneticists can employ for the propagation of economically important traits in livestock and poultry. In this chapter, we address the fundamental methods of the artificial insemination of poultry, including semen collection, semen evalu...

  4. Nanostructured artificial nacre

    Science.gov (United States)

    Tang, Zhiyong; Kotov, Nicholas A.; Magonov, Sergei; Ozturk, Birol

    2003-06-01

    Finding a synthetic pathway to artificial analogs of nacre and bones represents a fundamental milestone in the development of composite materials. The ordered brick-and-mortar arrangement of organic and inorganic layers is believed to be the most essential strength- and toughness-determining structural feature of nacre. It has also been found that the ionic crosslinking of tightly folded macromolecules is equally important. Here, we demonstrate that both structural features can be reproduced by sequential deposition of polyelectrolytes and clays. This simple process results in a nanoscale version of nacre with alternating organic and inorganic layers. The macromolecular folding effect reveals itself in the unique saw-tooth pattern of differential stretching curves attributed to the gradual breakage of ionic crosslinks in polyelectrolyte chains. The tensile strength of the prepared multilayers approached that of nacre, whereas their ultimate Young modulus was similar to that of lamellar bones. Structural and functional resemblance makes clay- polyelectrolyte multilayers a close replica of natural biocomposites. Their nanoscale nature enables elucidation of molecular processes occurring under stress.

  5. A simplified design of clamping system and fixtures for friction stir welding of aluminium alloys

    Directory of Open Access Journals (Sweden)

    Mohammed. M. Hasan

    2015-12-01

    Full Text Available Sound friction stir welds could be attained by using an active design of backing/clamping system with a proper selection of the welding parameters. This work presented a simplified design of fixtures and backing plates to be used for friction stir welding of aluminum alloys. The test-rig was constructed to prevent dispersal or lifting of the specimens throughout the joining process and to ensure uniform distribution of temperature along the plates. The workpieces were subjected to uniform lateral and vertical pressures by means of bolts and nuts. Compound backing plates and pressure bars with additional side plates were included to increase the heat sink. Several coupons of dissimilar aluminum alloys AA7075 and AA6061 were joined to inspect the validity of this design. The tests showed promising results with defects-free welds, good strength and smooth surface finish without geometric imperfection and gap creation between the welded specimens. Efficiency of the joint reached its maximum value of about 82% with respect to the ultimate strength of the AA6061 alloy at 1100 rpm rotation speed and 300 mm/min feed. These results encourage using and improving the present design for future studies of friction stir welding.

  6. A patch-clamp ASIC for nanopore-based DNA analysis.

    Science.gov (United States)

    Kim, Jungsuk; Maitra, Raj; Pedrotti, Kenneth D; Dunbar, William B

    2013-06-01

    In this paper, a fully integrated high-sensitivity patch-clamp system is proposed for single-molecule deoxyribonucleic acid (DNA) analysis using a nanopore sensor. This system is composed of two main blocks for amplification and compensation. The amplification block is composed of three stages: 1) a headstage, 2) a voltage-gain difference amplifier, and 3) a track-and-hold circuit, that amplify a minute ionic current variation sensed by the nanopore while the compensation block avoids the headstage saturation caused by the input parasitic capacitances during sensing. By employing design techniques novel for this application, such as an instrumentation--amplifier topology and a compensation switch, we minimize the deleterious effects of the input-offset voltage and the input parasitic capacitances while attaining hardware simplicity. This system is fabricated in a 0.35 μm 4M2P CMOS process and is demonstrated using an α-hemolysin protein nanopore for detection of individual molecules of single-stranded DNA that pass through the 1.5 nm-diameter pore. In future work, the refined system will functionalize single and multiple solid-state nanopores formed in integrated microfluidic devices for advanced DNA analysis, in scientific and diagnostic applications.

  7. The Virtual Teacher (VT) Paradigm: Learning New Patterns of Interpersonal Coordination Using the Human Dynamic Clamp.

    Science.gov (United States)

    Kostrubiec, Viviane; Dumas, Guillaume; Zanone, Pier-Giorgio; Kelso, J A Scott

    2015-01-01

    The Virtual Teacher paradigm, a version of the Human Dynamic Clamp (HDC), is introduced into studies of learning patterns of inter-personal coordination. Combining mathematical modeling and experimentation, we investigate how the HDC may be used as a Virtual Teacher (VT) to help humans co-produce and internalize new inter-personal coordination pattern(s). Human learners produced rhythmic finger movements whilst observing a computer-driven avatar, animated by dynamic equations stemming from the well-established Haken-Kelso-Bunz (1985) and Schöner-Kelso (1988) models of coordination. We demonstrate that the VT is successful in shifting the pattern co-produced by the VT-human system toward any value (Experiment 1) and that the VT can help humans learn unstable relative phasing patterns (Experiment 2). Using transfer entropy, we find that information flow from one partner to the other increases when VT-human coordination loses stability. This suggests that variable joint performance may actually facilitate interaction, and in the long run learning. VT appears to be a promising tool for exploring basic learning processes involved in social interaction, unraveling the dynamics of information flow between interacting partners, and providing possible rehabilitation opportunities.

  8. Elg1, an alternative subunit of the RFC clamp loader, preferentially interacts with SUMOylated PCNA.

    Science.gov (United States)

    Parnas, Oren; Zipin-Roitman, Adi; Pfander, Boris; Liefshitz, Batia; Mazor, Yuval; Ben-Aroya, Shay; Jentsch, Stefan; Kupiec, Martin

    2010-08-04

    Replication-factor C (RFC) is a protein complex that loads the processivity clamp PCNA onto DNA. Elg1 is a conserved protein with homology to the largest subunit of RFC, but its function remained enigmatic. Here, we show that yeast Elg1 interacts physically and genetically with PCNA, in a manner that depends on PCNA modification, and exhibits preferential affinity for SUMOylated PCNA. This interaction is mediated by three small ubiquitin-like modifier (SUMO)-interacting motifs and a PCNA-interacting protein box close to the N-terminus of Elg1. These motifs are important for the ability of Elg1 to maintain genomic stability. SUMOylated PCNA is known to recruit the helicase Srs2, and in the absence of Elg1, Srs2 and SUMOylated PCNA accumulate on chromatin. Strains carrying mutations in both ELG1 and SRS2 exhibit a synthetic fitness defect that depends on PCNA modification. Our results underscore the importance of Elg1, Srs2 and SUMOylated PCNA in the maintenance of genomic stability.

  9. The ELG1 clamp loader plays a role in sister chromatid cohesion.

    Directory of Open Access Journals (Sweden)

    Oren Parnas

    Full Text Available Mutations in the ELG1 gene of yeast lead to genomic instability, manifested in high levels of genetic recombination, chromosome loss, and gross chromosomal rearrangements. Elg1 shows similarity to the large subunit of the Replication Factor C clamp loader, and forms a RFC-like (RLC complex in conjunction with the 4 small RFC subunits. Two additional RLCs exist in yeast: in one of them the large subunit is Ctf18, and in the other, Rad24. Ctf18 has been characterized as the RLC that functions in sister chromatid cohesion. Here we present evidence that the Elg1 RLC (but not Rad24 also plays an important role in this process. A genetic screen identified the cohesin subunit Mcd1/Scc1 and its loader Scc2 as suppressors of the synthetic lethality between elg1 and ctf4. We describe genetic interactions between ELG1 and genes encoding cohesin subunits and their accessory proteins. We also show that defects in Elg1 lead to higher precocious sister chromatid separation, and that Ctf18 and Elg1 affect cohesion via a joint pathway. Finally, we localize both Ctf18 and Elg1 to chromatin and show that Elg1 plays a role in the recruitment of Ctf18. Our results suggest that Elg1, Ctf4, and Ctf18 may coordinate the relative movement of the replication fork with respect to the cohesin ring.

  10. A central swivel point in the RFC clamp loader controls PCNA opening and loading on DNA.

    Science.gov (United States)

    Sakato, Miho; O'Donnell, Mike; Hingorani, Manju M

    2012-02-17

    Replication factor C (RFC) is a five-subunit complex that loads proliferating cell nuclear antigen (PCNA) clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA(+) superfamily, and their ATPase activity drives interactions between the clamp loader, the clamp, and the ptDNA, leading to topologically linked PCNA·ptDNA. We report the kinetics of transient events in Saccharomyces cerevisiae RFC-catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing, and PCNA·ptDNA release. This detailed perspective enables assessment of individual RFC-A, RFC-B, RFC-C, RFC-D, and RFC-E subunit functions in the reaction mechanism. Functions have been ascribed to RFC subunits previously based on a steady-state analysis of 'arginine-finger' ATPase mutants; however, pre-steady-state analysis provides a different view. The central subunit RFC-C serves as a critical swivel point in the clamp loader. ATP binding to this subunit initiates RFC activation, and the clamp loader adopts a spiral conformation that stabilizes PCNA in a corresponding open spiral. The importance of RFC subunit response to ATP binding decreases as RFC-C>RFC-D>RFC-B, with RFC-A being unnecessary. RFC-C-dependent activation of RFC also enables ptDNA binding, leading to the formation of the RFC·ATP·PCNA(open)·ptDNA complex. Subsequent ATP hydrolysis leads to complex dissociation, with RFC-D activity contributing the most to rapid ptDNA release. The pivotal role of the RFC-B/C/D subunit ATPase core in clamp loading is consistent with the similar central location of all three ATPase active subunits of the Escherichia coli clamp loader. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Pre-Descemets endothelial keratoplasty: the PDEK clamp for successful PDEK.

    Science.gov (United States)

    Dua, H S; Said, D G

    2017-07-01

    PurposeTo design and produce a clamp that enables good handling of donor sclera-corneal disks, allows air to be injected in the corneal stroma and consistently provides pre-Descemets endothelial keratoplasty (PDEK) tissue by creation of a type-1 big bubble (BB) avoiding a type-2BB by shutting the fenestrations in the periphery of the pre-Descemets layer and preventing escape of air.Patients and methodsA clamp with spring loaded handles attached to two rings of 9 mm diameter and 1 mm width with a side port for insertion of a needle for air injection was designed and produced. The clamp was tested in 20 human donor sclera-corneal disks and refined over three prototypes. The final design was used for PDEK in 8 patients.ResultsThe clamp was able to prevent any escape of air or the formation of a type-2BB. By preventing air leak, it provided better control over the volume of air injected allowing for consistent formation of a type-1BB, which could be expanded to its full diameter by advancing the tip of the needle into the bubble cavity. Centration of tissue in the clamp was important. The clamp was used successfully to obtain PDEK tissue from 8 donor sclara-corneal disks for transplant in three eyes with pseudophakic bullous keratopathy and five eyes with pseudophakia and Fuchs' endothelial dystrophy.ConclusionThe PDEK clamp is a simple and useful instrument that will give surgeons the confidence of consistently obtaining PDEK tissue with ease and without the risk of separating the Descemets membrane in a type-2BB.

  12. Conformational Changes of the Clamp of the Protein Translocation ATPase SecA.

    Science.gov (United States)

    Chen, Yu; Bauer, Benedikt W; Rapoport, Tom A; Gumbart, James C

    2015-07-17

    Post-translational protein translocation across the bacterial plasma membrane is mediated by the interplay of the SecA ATPase and the protein-conducting SecY channel. SecA consists of several domains, including two nucleotide-binding domains (NBD1 and NBD2), a polypeptide cross-linking domain (PPXD), a helical scaffold domain (HSD), and a helical wing domain (HWD). PPXD, HSD, and NBD2 form a clamp that positions the polypeptide substrate above the channel so that it can be pushed into the channel by a two-helix finger of the HSD. How the substrate is accommodated in the clamp during translocation is unclear. Here, we report a crystal structure of Thermotoga maritima SecA at 1.9 Å resolution. Structural analysis and free-energy calculations indicate that the new structure represents an intermediate state during the transition of the clamp from an open to a closed conformation. Molecular dynamics simulations show that closure of the clamp occurs in two phases, an initial movement of PPXD, HSD, and HWD as a unit, followed by a movement of PPXD alone toward NBD2. Simulations in the presence of a polypeptide chain show that the substrate associates with the back of the clamp by dynamic hydrogen bonding and that the clamp is laterally closed by a conserved loop of the PPXD. Mutational disruption of clamp opening or closure abolishes protein translocation. These results suggest how conformational changes of SecA allow substrate binding and movement during protein translocation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Safety evaluation of large external fixation clamps and frames in a magnetic resonance environment.

    Science.gov (United States)

    Luechinger, Roger; Boesiger, Peter; Disegi, John A

    2007-07-01

    Large orthopedic external fixation clamps and related components were evaluated for force, torque, and heating response when subjected to the strong electromagnetic fields of magnetic-resonance (MR) imaging devices. Forces induced by a 3-Tesla (T) MR scanner were compiled for newly designed nonmagnetic clamps and older clamps that contained ferromagnetic components. Heating trials were performed in a 1.5 and in a 3 T MR scanner with two assembled external fixation frames. Forces of the newly designed clamps were more than a factor 2 lower as the gravitational force on the device whereas, magnetic forces on the older devices showed over 10 times the force induced by earth acceleration of gravity. No torque effects could be found for the newly designed clamps. Temperature measurements at the tips of Schanz screws in the 1.5 T MR scanner showed a rise of 0.7 degrees C for a pelvic frame and of 2.1 degrees C for a diamond knee bridge frame when normalized to a specific absorption rate (SAR) of 2 W/kg. The normalized temperature increases in the 3 T MR scanner were 0.9 degrees C for the pelvic frame and 1.1 degrees C for the knee bridge frame. Large external fixation frames assembled with the newly designed clamps (390 Series Clamps), carbon fiber reinforced rods, and implant quality 316L stainless steel Schanz screws met prevailing force and torque limits when tested in a 3-T field, and demonstrated temperature increase that met IEC-60601 guidelines for extremities. The influence of frame-induced eddy currents on the risk of peripheral nerve stimulation was not investigated. Copyright 2006 Wiley Periodicals, Inc.

  14. Results from the carbon-land model intercomparison project (C-LAMP) and availability of the data on the earth system grid (ESG)

    Science.gov (United States)

    Hoffman, F. M.; Covey, C. C.; Fung, I. Y.; Randerson, J. T.; Thornton, P. E.; Lee, Y.-H.; Rosenbloom, N. A.; Stöckli, R. C.; Running, S. W.; Bernholdt, D. E.; Williams, D. N.

    2007-07-01

    This paper describes the Carbon-Land Model Intercomparison Project (C-LAMP) being carried out through a collaboration between the Community Climate System Model (CCSM) Biogeochemistry Working Group, a DOE SciDAC-2 project, and the DOE Program for Climate Model Diagnosis and Intercomparison (PCMDI). The goal of the project is to intercompare terrestrial biogeochemistry models running within the CCSM framework to determine the best set of processes to include in future versions of CCSM. As a part of the project, observational datasets are being collected and used to score the scientific performance of these models following a well-defined set of metrics. In addition, metadata standards for terrestrial biosphere models are being developed to support archival and distribution of the C-LAMP model output via the Earth System Grid (ESG). Progress toward completion of this project and preliminary results from the first set of experiments are reported.

  15. Mismatch repair protein hMSH2–hMSH6 recognizes mismatches and forms sliding clamps within a D-loop recombination intermediate

    Science.gov (United States)

    Honda, Masayoshi; Okuno, Yusuke; Hengel, Sarah R.; Martín-López, Juana V.; Cook, Christopher P.; Amunugama, Ravindra; Soukup, Randal J.; Subramanyam, Shyamal; Fishel, Richard; Spies, Maria

    2014-01-01

    High fidelity homologous DNA recombination depends on mismatch repair (MMR), which antagonizes recombination between divergent sequences by rejecting heteroduplex DNA containing excessive nucleotide mismatches. The hMSH2–hMSH6 heterodimer is the first responder in postreplicative MMR and also plays a prominent role in heteroduplex rejection. Whether a similar molecular mechanism underlies its function in these two processes remains enigmatic. We have determined that hMSH2–hMSH6 efficiently recognizes mismatches within a D-loop recombination initiation intermediate. Mismatch recognition by hMSH2–hMSH6 is not abrogated by human replication protein A (HsRPA) bound to the displaced single-stranded DNA (ssDNA) or by HsRAD51. In addition, ATP-bound hMSH2–hMSH6 sliding clamps that are essential for downstream MMR processes are formed and constrained within the heteroduplex region of the D-loop. Moreover, the hMSH2–hMSH6 sliding clamps are stabilized on the D-loop by HsRPA bound to the displaced ssDNA. Our findings reveal similarities and differences in hMSH2–hMSH6 mismatch recognition and sliding-clamp formation between a D-loop recombination intermediate and linear duplex DNA. PMID:24395779

  16. Processing Semblances Induced through Inter-Postsynaptic Functional LINKs, Presumed Biological Parallels of K-Lines Proposed for Building Artificial Intelligence.

    Science.gov (United States)

    Vadakkan, Kunjumon I

    2011-01-01

    The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of internal sensation - namely, the semblion. In neuronal networks that undergo continuous oscillatory activity at certain levels of their organization re-activation of functional LINKs is expected to induce semblions, enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI). This paper also explains suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky's K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system.

  17. Application of response surface methodology and artificial neural network: modeling and optimization of Cr(VI) adsorption process using Dowex 1X8 anion exchange resin.

    Science.gov (United States)

    Harbi, Soumaya; Guesmi, Fatma; Tabassi, Dorra; Hannachi, Chiraz; Hamrouni, Bechir

    2016-01-01

    We report the adsorption efficiency of Cr(VI) on a strong anionic resin Dowex 1X8. The Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis of this adsorbent were investigated. Response surface methodology was applied to evaluate the main effects and interactions among initial pH, initial Cr(VI) concentration, adsorbent dose and temperature. Analysis of variance depicted that resin dose and initial pH were the most significant factors. Desirability function (DF) showed that the maximum Cr(VI) removal of 95.96% was obtained at initial pH 5, initial Cr(VI) concentration of 100 mg/L, resin dose of 2 g and temperature of 283 K. Additionally, a simulated industrial wastewater containing 14.95 mg/L of Cr(VI) was treated successfully by Dowex 1X8 at optimum conditions. Same experimental design was employed to develop the artificial neural network. Both models gave a high correlation coefficient (RRSM(2) = 0.932, RANN(2) = 0.996).

  18. Processing Semblances Induced through Inter-Postsynaptic Functional LINKs, Presumed Biological Parallels of K-Lines Proposed for Building Artificial Intelligence

    Science.gov (United States)

    Vadakkan, Kunjumon I.

    2011-01-01

    The internal sensation of memory, which is available only to the owner of an individual nervous system, is difficult to analyze for its basic elements of operation. We hypothesize that associative learning induces the formation of functional LINK between the postsynapses. During memory retrieval, the activation of either postsynapse re-activates the functional LINK evoking a semblance of sensory activity arriving at its opposite postsynapse, nature of which defines the basic unit of internal sensation – namely, the semblion. In neuronal networks that undergo continuous oscillatory activity at certain levels of their organization re-activation of functional LINKs is expected to induce semblions, enabling the system to continuously learn, self-organize, and demonstrate instantiation, features that can be utilized for developing artificial intelligence (AI). This paper also explains suitability of the inter-postsynaptic functional LINKs to meet the expectations of Minsky’s K-lines, basic elements of a memory theory generated to develop AI and methods to replicate semblances outside the nervous system. PMID:21845180

  19. Modelling the clamping force distribution among chips in press-pack IGBTs using the finite element method

    DEFF Research Database (Denmark)

    Hasmasan, Adrian Augustin; Busca, Christian; Teodorescu, Remus

    2012-01-01

    for the chip, because it influences contact electrical resistance, contact thermal resistance and power cycling capability. Ideally, the clamping force should be equally distributed among chips, in order to maximize the reliability of the PP IGBT. The model is built around a hypothetical PP IGBT with 9 chips......In this paper, a FEM (finite element method) based mechanical model for PP (press-pack) IGBTs (insulated gate bipolar transistors) is presented, which can be used to calculate the clamping force distribution among chips under various clamping conditions. The clamping force is an important parameter......, and it has numerous simplifications in order to reduce the simulation time as much as possible. The developed model is used to analyze the clamping force distribution among chips, in various study cases, where uniform and non-uniform clamping pressures are applied on the studied PP IGBT....

  20. Artificial intelligence in medicine.

    Science.gov (United States)

    Ramesh, A N; Kambhampati, C; Monson, J R T; Drew, P J

    2004-09-01

    Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of different artificial intelligent techniques is presented in this paper along with the review of important clinical applications. The proficiency of artificial intelligent techniques has been explored in almost every field of medicine. Artificial neural network was the most commonly used analytical tool whilst other artificial intelligent techniques such as fuzzy expert systems, evolutionary computation and hybrid intelligent systems have all been used in different clinical settings. Artificial intelligence techniques have the potential to be applied in almost every field of medicine. There is need for further clinical trials which are appropriately designed before these emergent techniques find application in the real clinical setting.

  1. Artificial intelligence in medicine.

    Science.gov (United States)

    Ramesh, A. N.; Kambhampati, C.; Monson, J. R. T.; Drew, P. J.

    2004-01-01

    INTRODUCTION: Artificial intelligence is a branch of computer science capable of analysing complex medical data. Their potential to exploit meaningful relationship with in a data set can be used in the diagnosis, treatment and predicting outcome in many clinical scenarios. METHODS: Medline and internet searches were carried out using the keywords 'artificial intelligence' and 'neural networks (computer)'. Further references were obtained by cross-referencing from key articles. An overview of different artificial intelligent techniques is presented in this paper along with the review of important clinical applications. RESULTS: The proficiency of artificial intelligent techniques has been explored in almost every field of medicine. Artificial neural network was the most commonly used analytical tool whilst other artificial intelligent techniques such as fuzzy expert systems, evolutionary computation and hybrid intelligent systems have all been used in different clinical settings. DISCUSSION: Artificial intelligence techniques have the potential to be applied in almost every field of medicine. There is need for further clinical trials which are appropriately designed before these emergent techniques find application in the real clinical setting. PMID:15333167

  2. Quo Vadis, Artificial Intelligence?

    Directory of Open Access Journals (Sweden)

    Daniel Berrar

    2010-01-01

    Full Text Available Since its conception in the mid 1950s, artificial intelligence with its great ambition to understand and emulate intelligence in natural and artificial environments alike is now a truly multidisciplinary field that reaches out and is inspired by a great diversity of other fields. Rapid advances in research and technology in various fields have created environments into which artificial intelligence could embed itself naturally and comfortably. Neuroscience with its desire to understand nervous systems of biological organisms and systems biology with its longing to comprehend, holistically, the multitude of complex interactions in biological systems are two such fields. They target ideals artificial intelligence has dreamt about for a long time including the computer simulation of an entire biological brain or the creation of new life forms from manipulations of cellular and genetic information in the laboratory. The scope for artificial intelligence in neuroscience and systems biology is extremely wide. This article investigates the standing of artificial intelligence in relation to neuroscience and systems biology and provides an outlook at new and exciting challenges for artificial intelligence in these fields. These challenges include, but are not necessarily limited to, the ability to learn from other projects and to be inventive, to understand the potential and exploit novel computing paradigms and environments, to specify and adhere to stringent standards and robust statistical frameworks, to be integrative, and to embrace openness principles.

  3. A single electrode voltage, current- and patch-clamp amplifier with complete stable series resistance compensation.

    Science.gov (United States)

    Strickholm, A

    1995-01-01

    An input headstage for single electrode voltage and current clamping is described which permits selecting desired operational modes during an experiment. These include cell attached or whole cell patch clamping, single micro-electrode voltage or current clamping, potential recording, iontophoresis and voltammetry. Input electrode series resistance with the electrode inserted in a cell or during whole cell patch clamping can be measured at any time. The unique circuitry allows complete compensation of the series resistance with high frequency response. The input series electrode resistance can also vary considerably around an initially set 100% compensation with intrinsic stability. An accelerator 'supercharger' or 'booster circuit' is included which can shorten the rise time of membrane potential to the command potential by a hundredfold. This improves the recording of early ion channel currents. Feedback resistors are selected remotely for the specific experimental need. Signal resolution in patch clamping is that expected from the thermal noise of the feedback resistor and electrode to membrane seal resistance. This headstage circuitry design thus allows interchangeable modes of operation and parameters during an experiment to obtain optimal conditions for signal detection and frequency response.

  4. Functional dissection of synaptic circuits: in vivo patch-clamp recording in neuroscience.

    Science.gov (United States)

    Tao, Can; Zhang, Guangwei; Xiong, Ying; Zhou, Yi

    2015-01-01

    Neuronal activity is dominated by synaptic inputs from excitatory or inhibitory neural circuits. With the development of in vivo patch-clamp recording, especially in vivo voltage-clamp recording, researchers can not only directly measure neuronal activity, such as spiking responses or membrane potential dynamics, but also quantify synaptic inputs from excitatory and inhibitory circuits in living animals. This approach enables researchers to directly unravel different synaptic components and to understand their underlying roles in particular brain functions. Combining in vivo patch-clamp recording with other techniques, such as two-photon imaging or optogenetics, can provide even clearer functional dissection of the synaptic contributions of different neurons or nuclei. Here, we summarized current applications and recent research progress using the in vivo patch-clamp recording method and focused on its role in the functional dissection of different synaptic inputs. The key factors of a successful in vivo patch-clamp experiment and possible solutions based on references and our experiences were also discussed.

  5. Novel Low Loss Active Voltage Clamp Circuit for Series Connection of RCGCT thyristors

    Science.gov (United States)

    Ito, Hiroshi; Suzuki, Akihiro; Iwata, Akihiko

    This paper describes novel low loss active voltage clamp circuits for the series connection of RCGCT thyristors. For high voltage converters the series connection of power semiconductor devices is an essential technique for direct switching of high voltages. Several protection circuits have been applied to the series connection of RCGCT thyristors such as CRD snubber circuits which suppress over-voltages across RCGCT thyristors, and voltage balancing resistors to equalize voltage sharing in steady states. However, significant losses in these protection circuits lower the converter’s efficiency. We propose novel low-loss protection circuits, which have active voltage clamp snubber circuits and static voltage balancing circuits. The clamp capacitor voltage of the active voltage clamp snubber circuits are designed to be higher than the equally divided DC-Link voltage. This method can reduce the loss of the clamp circuit to no more than 1/10 of that of the conventional CRD snubber. Also the static voltage balancing circuits compensate for the voltage imbalance generated by the difference in the leakage current between the series connection RCGCT thyristors.

  6. The interplay of primer-template DNA phosphorylation status and single-stranded DNA binding proteins in directing clamp loaders to the appropriate polarity of DNA.

    Science.gov (United States)

    Hayner, Jaclyn N; Douma, Lauren G; Bloom, Linda B

    2014-01-01

    Sliding clamps are loaded onto DNA by clamp loaders to serve the critical role of coordinating various enzymes on DNA. Clamp loaders must quickly and efficiently load clamps at primer/template (p/t) junctions containing a duplex region with a free 3'OH (3'DNA), but it is unclear how clamp loaders target these sites. To measure the Escherichia coli and Saccharomyces cerevisiae clamp loader specificity toward 3'DNA, fluorescent β and PCNA clamps were used to measure clamp closing triggered by DNA substrates of differing polarity, testing the role of both the 5'phosphate (5'P) and the presence of single-stranded binding proteins (SSBs). SSBs inhibit clamp loading by both clamp loaders on the incorrect polarity of DNA (5'DNA). The 5'P groups contribute selectivity to differing degrees for the two clamp loaders, suggesting variations in the mechanism by which clamp loaders target 3'DNA. Interestingly, the χ subunit of the E. coli clamp loader is not required for SSB to inhibit clamp loading on phosphorylated 5'DNA, showing that χ·SSB interactions are dispensable. These studies highlight a common role for SSBs in directing clamp loaders to 3'DNA, as well as uncover nuances in the mechanisms by which SSBs perform this vital role. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  7. Improving designer productivity. [artificial intelligence

    Science.gov (United States)

    Hill, Gary C.

    1992-01-01

    Designer and design team productivity improves with skill, experience, and the tools available. The design process involves numerous trials and errors, analyses, refinements, and addition of details. Computerized tools have greatly speeded the analysis, and now new theories and methods, emerging under the label Artificial Intelligence (AI), are being used to automate skill and experience. These tools improve designer productivity by capturing experience, emulating recognized skillful designers, and making the essence of complex programs easier to grasp. This paper outlines the aircraft design process in today's technology and business climate, presenting some of the challenges ahead and some of the promising AI methods for meeting these challenges.

  8. The interpretation of glucose clamp studies of long-acting insulin analogues: from physiology to marketing and back.

    Science.gov (United States)

    Swinnen, S G H A; Holleman, F; DeVries, J H

    2008-10-01

    Glucose clamp studies assessing the time-action profile of long-acting insulin analogues have reported conflicting results. In an attempt to reconcile the data, we organised an expert meeting of four leading European clamp groups, during which consensus was reached on some but not all points discussed. In this paper, which reflects our personal views only, we aim to provide guidance for readers and reviewers on the interpretation of this type of clamp study and to clarify its inherent limitations.Glucose clamp studies are either performed manually or using an automated procedure, but differences in clamp methodology hardly seem a satisfactory explanation for the conflicting results. (Un)conscious investigator-related bias, especially during manual studies, cannot be ruled out, despite attempts at blinding the study insulin during the clamp.The duration of action of study insulins is influenced by many factors, such as glucose and insulin levels prior to injection, endogenous insulin secretion, insulin dose, definitions used for onset and end of action, and insulin sensitivity (which is influenced by the necessity of fasting during the clamp). These factors limit the translation of clamp study results into daily practice.Because of the inherent limitations of the glucose clamp technique and the lack of reproducibility of the outcomes, its results should be regarded as no more than an indication of the clinical action profile of long-acting insulin preparations.

  9. Design and fabrication of a planar patch-clamp substrate using a silicon-on-insulator wafer

    International Nuclear Information System (INIS)

    Zhang Zhenlong; Liu Xiangyang; Mao Yanli

    2009-01-01

    The planar patch-clamp technique has been applied to high throughput screening in drug discovery. The key feature of this technique is the fabrication of a planar patch-clamp substrate using appropriate materials. In this study, a planar patch-clamp substrate was designed and fabricated using a silicon-on-insulator (SOI) wafer. The access resistance and capacitance of SOI-based planar patch-clamp substrates are smaller than those of bulk silicon-based planar substrates, which will reduce the distributed RC noise.

  10. The essential Drosophila CLAMP protein differentially regulates non-coding roX RNAs in male and females.

    Science.gov (United States)

    Urban, Jennifer A; Doherty, Caroline A; Jordan, William T; Bliss, Jacob E; Feng, Jessica; Soruco, Marcela M; Rieder, Leila E; Tsiarli, Maria A; Larschan, Erica N

    2017-06-01

    Heterogametic species require chromosome-wide gene regulation to compensate for differences in sex chromosome gene dosage. In Drosophila melanogaster, transcriptional output from the single male X-chromosome is equalized to that of XX females by recruitment of the male-specific lethal (MSL) complex, which increases transcript levels of active genes 2-fold. The MSL complex contains several protein components and two non-coding RNA on the X ( roX) RNAs that are transcriptionally activated by the MSL complex. We previously discovered that targeting of the MSL complex to the X-chromosome is dependent on the chromatin-linked adapter for MSL proteins (CLAMP) zinc finger protein. To better understand CLAMP function, we used the CRISPR/Cas9 genome editing system to generate a frameshift mutation in the clamp gene that eliminates expression of the CLAMP protein. We found that clamp null females die at the third instar larval stage, while almost all clamp null males die at earlier developmental stages. Moreover, we found that in clamp null females roX gene expression is activated, whereas in clamp null males roX gene expression is reduced. Therefore, CLAMP regulates roX abundance in a sex-specific manner. Our results provide new insights into sex-specific gene regulation by an essential transcription factor.

  11. Natural and artificial atoms for quantum computation

    Energy Technology Data Exchange (ETDEWEB)

    Buluta, Iulia; Ashhab, Sahel; Nori, Franco, E-mail: fnori@riken.jp [Advanced Science Institute, RIKEN, Wako-shi, Saitama, 351-0198 (Japan)

    2011-10-15

    Remarkable progress towards realizing quantum computation has been achieved using natural and artificial atoms as qubits. This paper presents a brief overview of the current status of different types of qubits. On the one hand, natural atoms (such as neutral atoms and ions) have long coherence times, and could be stored in large arrays, providing ideal 'quantum memories'. On the other hand, artificial atoms (such as superconducting circuits or semiconductor quantum dots) have the advantage of custom-designed features and could be used as 'quantum processing units'. Natural and artificial atoms can be coupled with each other and can also be interfaced with photons for long-distance communications. Hybrid devices made of natural/artificial atoms and photons may provide the next-generation design for quantum computers.

  12. The Effect of an Added Mass on the Frequency Shifts of a Clamped-Clamped Microbeam for Bio-Mass Detection

    KAUST Repository

    Bouchaala, Adam M.

    2016-12-05

    We present analytical formulations to calculate the induced resonance frequency shifts of electrically actuated clamped-clamped microbeams due to an added mass. Based on the Euler-Bernoulli beam theory, we investigate the linear dynamic responses of the beams added masses, which are modeled as discrete point masses. Analytical expressions based on perturbation techniques and a one-mode Galerkin approximation are developed to calculate accurately the frequency shifts under a DC voltage as a function of the added mass and position. The analytical results are compared to numerical solution of the eigenvalue problem. Results are shown for the fundamental as well as the higher-order modes of the beams. The results indicate a significant increase in the frequency shift, and hence the sensitivity of detection, when scaling down to nano scale and using higher-order modes.

  13. Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-05

    A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprung dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.

  14. Artifactual voltage response recorded from hair cells with patch-clamp amplifiers.

    Science.gov (United States)

    Masetto, S; Weng, T; Valli, P; Correia, M J

    1999-06-23

    Patch-clamp amplifiers (PCAs) are commonly used to characterize voltage- and current-clamp responses in the same cell. However, the cell membrane voltage response can be severely distorted by PCAs working in the current-clamp mode. Here we compare the voltage response of pigeon semicircular canal hair cells in situ, recorded with two different PCAs, and with a classic microelectrode bridge amplifier (BA). We found that the voltage response of hair cells recorded with PCAs differed significantly from that recorded with the BA. The true hair cell membrane voltage response to positive current steps was characterized by a strongly damped oscillation, whose frequency and duration depended on hair cell location in the sensory crista ampullaris.

  15. A simple technique to measure regional cerebral blood flow during intravascular ballon clamping

    International Nuclear Information System (INIS)

    Furuhata, Shigeru; Kubo, Atsushi; Kawase, Takeshi; Ibata, Yukio; Toya, Shigeo

    1988-01-01

    A case of giant internal carotid ophthalmic aneurysm was presented. In order to clarify whether the patient could tolerate carotid occlusion, a ballon clamping test was performed before surgery. The cerebral blood flow was measured using early imaging by single photon emission computed tomography (SPECT) with N-isopropyl-(iodine-123)-p-iodoamphetamine ( 123 I-IMP). When the ballon clamping test was performed the tracer was injected, and scanning was performed 35 minutes after removing the catheter. This tracer enabled a 'memory of blood flow' during temporary ischemia to determine the character of quick diffusion and slow wash out, that could not be performed by other methods of cerebral blood flow measurement. SPECT with 123 I-IMP can simplify the measurement of cerebral blood flow during the balloon clamping test. (author)

  16. Promoting physiologic transition at birth: re-examining resuscitation and the timing of cord clamping.

    Science.gov (United States)

    Niermeyer, Susan; Velaphi, Sithembiso

    2013-12-01

    Delayed clamping of the umbilical cord is recommended for term and preterm infants who do not require resuscitation. However, the approach to the newly born infant with signs of fetal compromise, prematurity and extremely low birthweight, or prolonged apnea is less clear. Human and experimental animal data show that delaying the clamping of the umbilical cord until after the onset of respirations promotes cardiovascular stability in the minutes immediately after birth. Rather than regarding delayed cord clamping as a fixed time period before resuscitation begins, a more physiologic concept of transition at birth should encompass the relative timing of onset of respirations and cord occlusion. Further research to explore the potential benefits of resuscitation with the cord intact is needed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Significance of Shrinkage Induced Clamping Pressure in Fiber-Matrix Bonding in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Stang, Henrik

    1996-01-01

    used in high performance cementitious composite materials.Assuming a Coulomb type of friction on the fiber/matrix interface andusing typical values for the frictional coefficient it is shownthat the shrinkage induced clamping pressure could be one of the mostimportant factors determining the frictional......The present paper accesses the significance of shrinkage inducedclamping pressure in fiber/matrix bonding mechanisms incementitious composite materials. The paper contains a description of an experimental setup whichallows mbox{measurement} of the clamping pressure which develops on anelastic...... inhomogeneity embedded in a matrix consisting of acementitious material undergoing shrinkage during hydration(autogenous shrinkage). Furthermore, the paperpresents the analysis necessary to perform an interpretation of the experimental results and which allows for thedetermination of the clamping pressure...

  18. Influence of non-steady state during isoglycemic hyperinsulinemic clamp in hypertension. A LIFE substudy

    DEFF Research Database (Denmark)

    Olsen, M H; Andersen, U B; Wachtell, K

    1999-01-01

    We wanted to investigate whether time to steady state was reached within 2 h of insulin infusion during isoglycemic hyperinsulinemic clamp, comparing the glucose uptake index (M/IG) with Bergman's insulin sensitivity index (Sip). We performed a 2-h oral glucose tolerance test and a 3-h isoglycemic...... hyperinsulinemic clamp in 26 young, healthy subjects and 43 elderly patients with unmedicated essential hypertension and left ventricular hypertrophy. The 3-h Sip correlated strongly with the 2-h M/IG in the patients (r = 0.88, p .... Because the 2-h M/IG correlated strongly with the 3-h Sip with relatively narrow limits of agreement, it is a good measure of insulin sensitivity. However, a 2-h clamp results in lower insulin sensitivity values in elderly, hypertensive patients due to the fact that steady state is not reached...

  19. The evaluation on clamping force of high strength bolts by length parameter

    International Nuclear Information System (INIS)

    Kim, Kang-Seok; Nah, Hwan-Seon; Lee, Hyeon-Ju; Lee, Kang-Min

    2009-01-01

    It has been reported that the length parameter of high strength bolts results in the variance in tension loads. The required turn for each length is specified in AISC RCSC specification. This study was focused on evaluating any influence on the clamping torque subjected to length parameter of high strength bolts. The two kinds of high strength bolts of specimen are as follows; High Strength Hexagon bolt defined on ASTM A490 and Torque Shear Bolt on KS B 2819. The length parameter ranged from 60mm(3d) to 140mm(7d). The torque, turn of nut and the clamping force were analyzed to review whether length parameter can be affected on the required tension load. To test whether the length parameter has an impact on the torque and turn of nut for the required strength and clamping force, statistical analysis is carried out. (author)

  20. The artificial leaf.

    Science.gov (United States)

    Nocera, Daniel G

    2012-05-15

    To convert the energy of sunlight into chemical energy, the leaf splits water via the photosynthetic process to produce molecular oxygen and hydrogen, which is in a form of separated protons and electrons. The primary steps of natural photosynthesis involve the absorption of sunlight and its conversion into spatially separated electron-hole pairs. The holes of this wireless current are captured by the oxygen evolving complex (OEC) of photosystem II (PSII) to oxidize water to oxygen. The electrons and protons produced as a byproduct of the OEC reaction are captured by ferrodoxin of photosystem I. With the aid of ferrodoxin-NADP(+) reductase, they are used to produce hydrogen in the form of NADPH. For a synthetic material to realize the solar energy conversion function of the leaf, the light-absorbing material must capture a solar photon to generate a wireless current that is harnessed by catalysts, which drive the four electron/hole fuel-forming water-splitting reaction under benign conditions and under 1 sun (100 mW/cm(2)) illumination. This Account describes the construction of an artificial leaf comprising earth-abundant elements by interfacing a triple junction, amorphous silicon photovoltaic with hydrogen- and oxygen-evolving catalysts made from a ternary alloy (NiMoZn) and a cobalt-phosphate cluster (Co-OEC), respectively. The latter captures the structural and functional attributes of the PSII-OEC. Similar to the PSII-OEC, the Co-OEC self-assembles upon oxidation of an earth-abundant metal ion from 2+ to 3+, may operate in natural water at room temperature, and is self-healing. The Co-OEC also activates H(2)O by a proton-coupled electron transfer mechanism in which the Co-OEC is increased by four hole equivalents akin to the S-state pumping of the Kok cycle of PSII. X-ray absorption spectroscopy studies have established that the Co-OEC is a structural relative of Mn(3)CaO(4)-Mn cubane of the PSII-OEC, where Co replaces Mn and the cubane is extended in a