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Sample records for 177lu-bombesin analog developed

  1. In vitro and in vivo studies in Balb-c and nude mice of a new {sup 177}Lu-Bombesin analog developed for prostate tumor diagnosis and treatment

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, Priscilla B.; Santos, Josefina S.; Couto, Renata M.; Araujo, Elaine B. de; Mengatti, Jair [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Diretoria de Radiofarmacia], e-mail: priscillapujatti@yahoo.com.br; Suzuki, Miriam F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia

    2009-07-01

    In this work we describe the radiolabeling with {sup 177}Lu and some properties of the novel bombesin analog BBNp6 - DOTA-X-BBN(6-14), where X is a spacer of six aminoacids. Bombesin (BBN) is an analog of human gastrin releasing peptide (GRP) isolated from the skin of the frog Bombina bombina in 1970. Development of radiolabeled BBN derivatives as agents for diagnostic imaging and systemic radiotherapy has increased considerable because of the observation that GRP receptors (GRPr) are over-expressed in a variety of human tumor cells, such as prostate tumor cells. {sup 177}Lu-labeled peptides are attractive due to the excellent radiophysical properties and commercial availability of the radiometal. BBNp6 was labeled with high yield after reacting with 92.5 MBq of {sup 177}LuCl3 at 90 deg C for 30 minutes and this mixture kept stable for more than 96 hours at 4 deg C and 1 hour in human plasma. In vivo studies showed a multicompartimental distribution model with fast blood clearance, mainly performed by renal pathway. In addition, {sup 177}Lu-BBNp6 showed high affinity for PC-3 tumor xenografts, but not for pancreas and intestine (GRP positive tissues), suggesting its specificity and usefulness for prostate tumor treatment. Moreover, scintigraphic images showed that this derivative can also be a tool in this tumor diagnosis. So, BBNp6 is a promising radiopharmaceutical for prostate tumor imaging and treatment. (author)

  2. Analogy Mapping Development for Learning Programming

    Science.gov (United States)

    Sukamto, R. A.; Prabawa, H. W.; Kurniawati, S.

    2017-02-01

    Programming skill is an important skill for computer science students, whereas nowadays, there many computer science students are lack of skills and information technology knowledges in Indonesia. This is contrary with the implementation of the ASEAN Economic Community (AEC) since the end of 2015 which is the qualified worker needed. This study provided an effort for nailing programming skills by mapping program code to visual analogies as learning media. The developed media was based on state machine and compiler principle and was implemented in C programming language. The state of every basic condition in programming were successful determined as analogy visualization.

  3. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    Directory of Open Access Journals (Sweden)

    Shi Ke

    2012-02-01

    Full Text Available Two kinds of fluorescent hyaluronan (HA analogs, one serving as normal imaging agent and the other used as a biosensitive contrast agent, were developed for the investigation of HA uptake and degradation. Our approach of developing HA imaging agents depends on labeling HA with varying molar percentages of a near-infrared (NIR dye. At low labeling ratios, the hyaluronan uptake can be directly imaged while at high labeling ratios, the fluorescent signal is quenched and signal generation occurs only after degradation. It is found that the conjugate containing 1%–2% NIR dye can be used as a normal optical imaging agent, while bioactivable imaging agents are formed at 6% to 17% dye loading. It was determined that the conjugation of dye to HA with different loading percentages does not impact HA biodegradation by hyaluronidase (Hyal. The feasibility of using these two NIR fluorescent hyaluronan analogs for HA investigation was evaluated in vivo with optical imaging. The data demonstrates that the 1% dye loaded fluorescent HA can be used to monitor the behavior of HA and its fragments, whereas bioactivatable HA imaging agent (17% dye in HA is more suitable for detecting HA fragments.

  4. Development of analogical problem-solving skill.

    Science.gov (United States)

    Holyoak, K J; Junn, E N; Billman, D O

    1984-12-01

    3 experiments were performed to assess children's ability to solve a problem by analogy to a superficially dissimilar situation. Preschoolers and fifth and sixth graders were asked to solve a problem that allowed multiple solutions. Some subjects were first read a story that included an analogous problem and its solution. When the mapping between the relations involved in the corresponding solutions was relatively simple, and the corresponding instruments were perceptually and functionally similar, even preschoolers were able to use the analogy to derive a solution to the transfer problem (Experiment 1). Furthermore, salient similarity of the instruments was neither sufficient (Experiment 2) nor necessary (Experiment 3) for success by preschool subjects. When the story analog mapped well onto the transfer problem, 4-year-olds were often able to generate a solution that required transformation of an object with little perceptual or semantic similarity to the instrument used in the base analog (Experiment 3). The older children used analogies in a manner qualitatively similar to that observed in comparable studies with adults (Experiment 1), whereas the younger children exhibited different limitations.

  5. Developing a 300C Analog Tool for EGS

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy

    2015-03-23

    This paper covers the development of a 300°C geothermal well monitoring tool for supporting future EGS (enhanced geothermal systems) power production. This is the first of 3 tools planed. This is an analog tool designed for monitoring well pressure and temperature. There is discussion on 3 different circuit topologies and the development of the supporting surface electronics and software. There is information on testing electronic circuits and component. One of the major components is the cable used to connect the analog tool to the surface.

  6. Analog Video Authentication and Seal Verification Equipment Development

    Energy Technology Data Exchange (ETDEWEB)

    Gregory Lancaster

    2012-09-01

    Under contract to the US Department of Energy in support of arms control treaty verification activities, the Savannah River National Laboratory in conjunction with the Pacific Northwest National Laboratory, the Idaho National Laboratory and Milagro Consulting, LLC developed equipment for use within a chain of custody regime. This paper discussed two specific devices, the Authentication Through the Lens (ATL) analog video authentication system and a photographic multi-seal reader. Both of these devices have been demonstrated in a field trial, and the experience gained throughout will also be discussed. Typically, cryptographic methods are used to prove the authenticity of digital images and video used in arms control chain of custody applications. However, in some applications analog cameras are used. Since cryptographic authentication methods will not work on analog video streams, a simple method of authenticating analog video was developed and tested. A photographic multi-seal reader was developed to image different types of visual unique identifiers for use in chain of custody and authentication activities. This seal reader is unique in its ability to image various types of seals including the Cobra Seal, Reflective Particle Tags, and adhesive seals. Flicker comparison is used to compare before and after images collected with the seal reader in order to detect tampering and verify the integrity of the seal.

  7. Social Analogical Reasoning in School-Aged Children with Autism Spectrum Disorder and Typically Developing Peers

    Science.gov (United States)

    Green, Adam E.; Kenworthy, Lauren; Gallagher, Natalie M.; Antezana, Ligia; Mosner, Maya G.; Krieg, Samantha; Dudley, Katherina; Ratto, Allison; Yerys, Benjamin E.

    2017-01-01

    Analogical reasoning is an important mechanism for social cognition in typically developing children, and recent evidence suggests that some forms of analogical reasoning may be preserved in autism spectrum disorder. An unanswered question is whether children with autism spectrum disorder can apply analogical reasoning to social information. In…

  8. Lunar Analog

    Science.gov (United States)

    Cromwell, Ronita L.

    2009-01-01

    In this viewgraph presentation, a ground-based lunar analog is developed for the return of manned space flight to the Moon. The contents include: 1) Digital Astronaut; 2) Bed Design; 3) Lunar Analog Feasibility Study; 4) Preliminary Data; 5) Pre-pilot Study; 6) Selection of Stockings; 7) Lunar Analog Pilot Study; 8) Bed Design for Lunar Analog Pilot.

  9. Social analogical reasoning in school-aged children with autism spectrum disorder and typically developing peers.

    Science.gov (United States)

    Green, Adam E; Kenworthy, Lauren; Gallagher, Natalie M; Antezana, Ligia; Mosner, Maya G; Krieg, Samantha; Dudley, Katherina; Ratto, Allison; Yerys, Benjamin E

    2017-05-01

    Analogical reasoning is an important mechanism for social cognition in typically developing children, and recent evidence suggests that some forms of analogical reasoning may be preserved in autism spectrum disorder. An unanswered question is whether children with autism spectrum disorder can apply analogical reasoning to social information. In all, 92 children with autism spectrum disorder completed a social content analogical reasoning task presented via photographs of real-world social interactions. Autism spectrum disorder participants exhibited performance that was well above chance and was not significantly worse than age- and intelligence quotient-matched typically developing children. Investigating the relationship of social content analogical reasoning performance to age in this cross-sectional dataset indicated similar developmental trajectories in the autism spectrum disorder and typically developing children groups. These findings provide new support for intact analogical reasoning in autism spectrum disorder and have theoretical implications for analogy as a metacognitive skill that may be at least partially dissociable from general deficits in processing social content. As an initial study of social analogical reasoning in children with autism spectrum disorder, this study focused on a basic research question with limited ecological validity. Evidence that children with autism spectrum disorder can apply analogical reasoning ability to social content may have long-range applied implications for exploring how this capacity might be channeled to improve social cognition in daily life.

  10. Development of a stable phosphoarginine analog for producing phosphoarginine antibodies.

    Science.gov (United States)

    Ouyang, Han; Fu, Chuan; Fu, Songsen; Ji, Zhe; Sun, Ying; Deng, Peiran; Zhao, Yufen

    2016-02-14

    Protein phosphorylation is one of the most common and extensively studied post-translational modifications (PTMs). Compared to the O-phosphorylation on Ser, Thr and Tyr residues, our understanding of arginine phosphorylation is relatively limited, both in prokaryotes and eukaryotes, due to the intrinsic instability of phosphoarginine (pArg) and the lack of a feasible method to produce anti-pArg antibodies. We report the design and synthesis of a stable pArg analog, in which the labile N-P bond is replaced with a non-hydrolyzable C-P bond. Significantly, this analog was successfully used as a hapten to raise an immune response and the first mouse polyclonal antibody that specifically recognizes pArg-containing peptides and proteins was produced using analog-KLH conjugated as the immunogen. The generated antibody shows excellent specificity towards pArg-containing peptides and proteins, and could be used for a variety of biological detection methods. This provides us an invaluable tool to unravel the mystery of the biological function of pArg.

  11. Development of neuropeptide analogs capable of traversing the integument: A case study using diapause hormone analogs in Helicoverpa zea.

    Science.gov (United States)

    Zhang, Qirui; Nachman, Ronald J; Kaczmarek, Krzysztof; Kierus, Krzysztof; Zabrocki, Janusz; Denlinger, David L

    2015-12-01

    Diapause hormone and its analogs terminate pupal diapause in Helicoverpa zea when injected, but if such agents are to be used as effective diapause disruptors it will be essential to develop simple techniques for administering active compounds that can exert their effect by penetrating the insect epidermis. In the current study, we used two molecules previously shown to have high diapause-terminating activity as lead molecules to rationally design and synthesize new amphiphilic compounds with modified hydrophobic components. An assay for diapause termination identified 13 active compounds with EC50's ranging from 0.9 to 46.0 pmol per pupa. Three compounds, Decyl-1963, Dodecyl-1967, and Heptyl-1965, selected from the 13 compounds most active in breaking diapause following injection, also successfully prevented newly-formed pupae from entering diapause when applied topically. These compounds feature straight-chain, aliphatic hydrocarbons from 7 to 12 carbons in length; DH analogs with either a short-chain length of 4 or an aromatic phenethyl group failed to act topically. Compared to a high diapause incidence of 80-90% in controls, diapause incidence in pupae receiving a 10 nmole topical application of Decyl-1963, Dodecyl-1967, or Heptyl-1965 dropped to 30-45%. Decyl-1963 and Dodecyl-1967 also remained effective when topically applied at the 1 nmole level. These results suggest the feasibility of developing DH agonists that can be applied topically and suggest the identity of new lead molecules for development of additional topically-active DH analogs. The ability to penetrate the insect epidermis and/or midgut lining is critical if such agents are to be considered for future use as pest management tools.

  12. Cognitive Science Questions for Cognitive Development: The Concepts of Learning, Analogy, and Capacity.

    Science.gov (United States)

    Halford, Graeme S.; McCredden, J. E.

    1998-01-01

    The implications of three concepts from cognitive science for understanding of cognitive development are reviewed. These are (1) learning (and induction), (2) analogy, and (3) capacity. A model of analogical reasoning is discussed that specifies changes in representations over age that explain phenomena previously thought to be stage-related. (SLD)

  13. High school biology students' participation in a year-long sequence of analogical activities: The relationship of development of analogical thought to student learning and classroom interactions

    Science.gov (United States)

    Hackney, Marcella Wichser

    1999-10-01

    This research explored development of analogical thought through high school biology students' participation in a year-long sequence of analogical activities. Analogizing involves: selecting a familiar analog; mapping similarities and differences between the analog and less familiar target; making inferences from the analogy; evaluating validity of the inferences; and ultimately, understanding the biological target (Holyoak & Thagard, 1995). This investigation considered: student development of independence in learning through analogical thought, student learning of biology, the relationship between development of students' analogical thinking and students' learning of biology, and the quality of student interactions in the classroom This researcher, as teacher participant, used three approaches for teaching by analogy: traditional didactic, teacher-guided, and analogy-generated-by-the-student (Zeitoun, 1983). Within cooperative groups, students in one honors biology class actively engaged in research-based analogical activities that targeted specific biological topics. Two honors biology classes participated in similar, but nonanalogical activities that targeted the same biological topics. This two-class comparison group permitted analytical separation of effects of the analogical emphasis from the effects of biology content and activity-based learning. Data collected included: fieldnotes of researcher observations, student responses to guidesheets, tapes of group interactions, student products, student perceptions survey evaluations, ratings of students' expressed analogical development, pre- and posttest scores on a biology achievement test, essay responses, and selected student interviews. These data formed the basis for researcher qualitative analysis, augmented by quantitative techniques. Through participation in the sequence of analogical activities, students developed their abilities to engage in the processes of analogical thinking, but attained different

  14. [Development of the modern biological analogy concept in the 19th century].

    Science.gov (United States)

    Bäumer, A

    1989-01-01

    At the beginning of the 19th century the term analogy was still synonymous with similarity, as for example in the case of Georges Cuvier. Exact criteria for determining analogy are first found in the work of Etienne Geoffroy Saint-Hilaire. Thereupon the English scientists Sharp MacLeay, William Swainson, John Obadiah Westwood and Edwin Strickland distinguished between analogy as correspondence between certain parts of the organism, i. e. only superficial resemblance, and affinity as an essential similarity in some remarkable aspects of form. Relying on these theories Richard Owen developed his theory of analogy ("a part which has the same function as another") and homology ("the same organ in different animals under every variety of form and function"). The criteria to distinguish between these two terms had to be modified and specified when the theory of evolution was developed by Charles Darwin. In the work of Thomas Henry Huxley, Ernst Haeckel and Carl Gegenbaur the modern biological term of analogy was developed, but at the same time it lost much of its importance and homology as a criterion for natural affinity became the central objective of further biological research.

  15. Instructional Development as a Social Movement: An Illustration of Analogical Theorizing.

    Science.gov (United States)

    Mellon, Constance A.

    1983-01-01

    Examines the application of naturalistic inquiry to the field of instructional development and suggests that such inquiry needs to be informed by research traditions in sociology. Drawing on social movement theory, an example of analogical theorizing is presented illustrating how this theory can be applied to exploration of instructional…

  16. Design, development, and fabrication of a electronic analog microminiaturized electronic analog signal to discrete time interval converter

    Science.gov (United States)

    Schoenfeld, A. D.; Schuegraf, K. K.

    1973-01-01

    The microminiaturization of an electronic analog signal to discrete time interval converter is presented. Discrete components and integrated circuits comprising the converter were assembled on a thin-film ceramic substrate containing nichrome resistors with gold interconnections. The finished assembly is enclosed in a flat package measuring 3.30 by 4.57 centimeters. The module can be used whenever conversion of analog to digital signals is required, in particular for the purpose of regulation by means of pulse modulation. In conjunction with a precision voltage reference, the module was applied to control the duty cycle of a switching regulator within a temperature range of -55 C to +125 C, and an input voltage range of 10V to 35V. The output-voltage variation was less than + or - 300 parts per million, i.e., less than + or - 3mV for a 10V output.

  17. Development of photodetectors for recording lidar signals in the photon counting and analog modes

    Science.gov (United States)

    Slesar, A. S.; Chaikovskii, A. P.; Denisov, S. V.; Korol, M. M.; Osipenko, F. P.; Balin, Yu. S.; Kokhanenko, G. P.; Penner, I. E.; Novoselov, M. M.

    2015-11-01

    A number of unified photodetector modules providing for recording lidar signals in the wavelength range from 0.26 to 1.6 μm in the modes of analog signals and photon counting are developed on the basis of photomultiplier tubes and avalanche photodiodes. The software is created for control of the photodetector modules, as well as the test bench for measuring their characteristics is designed.

  18. Which Way Is Up? Thomas S. Kuhn's Analogy to Conceptual Development in Childhood

    Science.gov (United States)

    Levine, Alexander T.

    In the Preface to his Structure Of Scientific Revolutions, Thomas S. Kuhn let it be known that his view of scientific development was indebted to the work of pioneering developmental psychologist Jean Piaget. Piaget's model of conceptual development in childhood, on which the child passes through several discontinuous stages, served as the template for Kuhn's reading of the history of a scientific discipline, on which mutually incommensurable periods of normal science are separated by scientific revolutions. The analogy to conceptual change in childhood pervades Kuhn's corpus, serving as the central motif in his well-known essays, A Function for Thought Experiments and Second Thoughts on Paradigms. But it is deeply problematic. For as a careful student of Piaget might note, Piaget, and the developmental psychologists he inspired, relied on the same analogy, but with the order of epistemic dependencies reversed. One begins to worry that Kuhn's use of the analogy, and its subsequent re-use by developmental psychologists, sneaks a vicious circularity into our understanding of important processes. This circularity is grounds for some concern on the part of science educators accustomed to employing such Kuhnian notions as incommensurability and paradigm.

  19. A Development of the Calibration Tool Applied on Analog I/O Modules for Safety-related Controller

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Kyun; Yun, Dong-Hwa; Lee, Myeong-Kyun; Yoo, Kwan-Woo [SOOSAN ENS Co., Seoul (Korea, Republic of)

    2016-10-15

    The purpose of this paper is to develop the calibration tool for analog input/output(I/O) modules. Those modules are components in POSAFE-Q which is a programmable logic controller(PLC) that has been developed for the evaluation of safety-related. In this paper, performance improvement of analog I/O modules is presented by developing and applying the calibration tool for each channel in analog I/O modules. With this tool, the input signal to an analog input module and the output signal from an analog output module are able to be satisfied with a reference value of sensor type and an accuracy of all modules. With RS-232 communication, the manual calibration tool is developed for analog I/O modules of an existing and up-to-date version in POSAFE-Q PLC. As a result of applying this tool, the converted value is performant for a type of input sensor and an accuracy of analog I/O modules.

  20. The SIRIUS Mixed analog-digital ASIC developed for the LOFT LAD and WFM instruments

    CERN Document Server

    Cros, A; Moutaye, E; Ravera, L; Barret, D; Caïs, P; Clédassou, R; Bodin, P; Seyler, JY; Bonzo, A; Feroci, M; Labanti, C; Evangelista, Y; Favre, Y

    2014-01-01

    We report on the development and characterization of the low-noise, low power, mixed analog-digital SIRIUS ASICs for both the LAD and WFM X-ray instruments of LOFT. The ASICs we developed are reading out large area silicon drift detectors (SDD). Stringent requirements in terms of noise (ENC of 17 e- to achieve an energy resolution on the LAD of 200 eV FWHM at 6 keV) and power consumption (650 {\\mu}W per channel) were basis for the ASICs design. These SIRIUS ASICs are developed to match SDD detectors characteristics: 16 channels ASICs adapted for the LAD (970 microns pitch) and 64 channels for the WFM (145 microns pitch) will be fabricated. The ASICs were developed with the 180nm mixed technology of TSMC.

  1. Developmental Patterns in the Solution of Verbal Analogies. Technical Report No. 3. Cognitive Development Series.

    Science.gov (United States)

    Sternberg, Robert J.; Nigro, Georgia

    Developmental patterns in the solution of verbal analogies, especially the recognition of higher-order analogical relations, were traced. The investigation sought to: (1) provide new developmental tests of a componential theory of analogical reasoning; (2) identify strategy changes during the transition from midchildhood (grade 3) to adulthood…

  2. Development of the analog ASIC for multi-channel readout X-ray CCD camera

    CERN Document Server

    Nakajima, Hiroshi; Idehara, Toshihiro; Anabuki, Naohisa; Tsunemi, Hiroshi; Doty, John P; Ikeda, Hirokazu; Katayama, Haruyoshi; Kitamura, Hisashi; Uchihori, Yukio; 10.1016/j.nima.2010.12.174

    2011-01-01

    We report on the performance of an analog application-specific integrated circuit (ASIC) developed aiming for the front-end electronics of the X-ray CCDcamera system onboard the next X-ray astronomical satellite, ASTRO-H. It has four identical channels that simultaneously process the CCD signals. Distinctive capability of analog-to-digital conversion enables us to construct a CCD camera body that outputs only digital signals. As the result of the front-end electronics test, it works properly with low input noise of =<30 uV at the pixel rate below 100 kHz. The power consumption is sufficiently low of about 150 mW/chip. The input signal range of 720 mV covers the effective energy range of the typical X-ray photon counting CCD (up to 20 keV). The integrated non-linearity is 0.2% that is similar as those of the conventional CCDs in orbit. We also performed a radiation tolerance test against the total ionizing dose (TID) effect and the single event effect. The irradiation test using 60Co and proton beam showed ...

  3. Estrogenic effects of several BPA analogs in the developing zebrafish brain

    Directory of Open Access Journals (Sweden)

    Joel eCano-Nicolau

    2016-03-01

    Full Text Available Important set of studies have demonstrated the endocrine disrupting activity of Bisphenol A (BPA. The present work aimed at defining estrogenic-like activity of several BPA structural analogs, including BPS, BPF, BPAF, and BPAP, on 4-day or 7-day post-fertilization (dpf zebrafish larva as an in vivo model. We measured the induction level of the estrogen-sensitive marker cyp19a1b gene (Aromatase B, expressed in the brain, using three different in situ/in vivo strategies: 1 Quantification of cyp19a1b transcripts using RT-qPCR in wild type 7-dpf larva brains exposed to bisphenols ; 2 Detection and distribution of cyp19a1b transcripts using in situ hybridization on 7-dpf brain sections (hypothalamus; and 3 Quantification of the cyp19a1b promoter activity in live cyp19a1b-GFP transgenic zebrafish (EASZY assay at 4-dpf larval stage. These three different experimental approaches demonstrated that BPS, BPF or BPAF exposure, similarly to BPA, significantly activates the expression of the estrogenic marker in the brain of developing zebrafish. In vitro experiments using both reporter gene assay in a glial cell context and competitive ligand binding assays strongly suggested that up-regulation of cyp19a1b is largely mediated by the zebrafish estrogen nuclear receptor alpha (zfERα. Importantly, and in contrast to other tested bisphenol A analogs, the bisphenol AP (BPAP did not show estrogenic activity in our model.

  4. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  5. Development of analog-digital readout integrated circuits for infrared focal plane arrays

    Science.gov (United States)

    Dem'yanenko, M. A.; Kozlov, A. I.; Marchishin, I. V.; Ovsyuk, V. N.

    2016-11-01

    This paper describes the design of readout integrated circuits (ROICs) for hybrid infrared focal plane arrays (IR FPAs). This work contains the estimation of the noise equivalent temperature difference (NETD) of IR FPAs based on frame and row integration of pixel signals in the spectral ranges of 8 to 14 and 3 to 5 μm. This paper also describes the development of ROICs for IR FPAs created with the use of mercury—cadmium—telluride (MCT) photodiodes and quantum well infrared photodetectors (QWIPs). The designed ROICs ensure the use of matrix and linear photodetector chips, including those with increased dark currents, in order to produce IR FPAs with temperature resolution corresponding to the world level of array analogs.

  6. Development of analog solid-state photo-detectors for Positron Emission Tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bisogni, Maria Giuseppina, E-mail: giuseppina.bisogni@pi.infn.it; Morrocchi, Matteo

    2016-02-11

    Solid-state photo-detectors are one of the main innovations of past century in the field of sensors. First produced in the early forties with the invention of the p–n junction in silicon and the study of its optical properties, photo-detectors received a major boost in the sixties when the p-i-n (PIN) photodiode was developed and successfully used in several applications. The development of devices with internal gain, avalanche photodiodes (APD) first and then Geiger-mode avalanche photodiodes, named single photon avalanche diode (SPAD), leads to a substantial improvement in sensitivity and allowed single photon detection. Later on, thousands of SPADs have been assembled in arrays of few millimeters squared (named SiPM, silicon photo-multiplier) with single photon resolution. The high internal gain of SiPMs, together with other features peculiar of the silicon technology like compactness, speed and compatibility with magnetic fields, promoted SiPMs as the principal photo-detector competitor of photomultipliers in many applications from radiation detection to medical imaging. This paper provides a review of the properties of analog solid-state photo-detectors. Particular emphasis is given to latest advances on Positron Emission Tomography instrumentation boosted by the adoption of the silicon photo-detectors as an alternative to photomultiplier tubes (PMTs). Special attention is dedicated to the SiPMs, which are playing a key role in the development of innovative scanners.

  7. Development of analog solid-state photo-detectors for Positron Emission Tomography

    Science.gov (United States)

    Bisogni, Maria Giuseppina; Morrocchi, Matteo

    2016-02-01

    Solid-state photo-detectors are one of the main innovations of past century in the field of sensors. First produced in the early forties with the invention of the p-n junction in silicon and the study of its optical properties, photo-detectors received a major boost in the sixties when the p-i-n (PIN) photodiode was developed and successfully used in several applications. The development of devices with internal gain, avalanche photodiodes (APD) first and then Geiger-mode avalanche photodiodes, named single photon avalanche diode (SPAD), leads to a substantial improvement in sensitivity and allowed single photon detection. Later on, thousands of SPADs have been assembled in arrays of few millimeters squared (named SiPM, silicon photo-multiplier) with single photon resolution. The high internal gain of SiPMs, together with other features peculiar of the silicon technology like compactness, speed and compatibility with magnetic fields, promoted SiPMs as the principal photo-detector competitor of photomultipliers in many applications from radiation detection to medical imaging. This paper provides a review of the properties of analog solid-state photo-detectors. Particular emphasis is given to latest advances on Positron Emission Tomography instrumentation boosted by the adoption of the silicon photo-detectors as an alternative to photomultiplier tubes (PMTs). Special attention is dedicated to the SiPMs, which are playing a key role in the development of innovative scanners.

  8. Structured Analog CMOS Design

    CERN Document Server

    Stefanovic, Danica

    2008-01-01

    Structured Analog CMOS Design describes a structured analog design approach that makes it possible to simplify complex analog design problems and develop a design strategy that can be used for the design of large number of analog cells. It intentionally avoids treating the analog design as a mathematical problem, developing a design procedure based on the understanding of device physics and approximations that give insight into parameter interdependences. The proposed transistor-level design procedure is based on the EKV modeling approach and relies on the device inversion level as a fundament

  9. TOWARDS A MATHEMATICAL THEORY OF ANALOGY

    OpenAIRE

    Haraguchi, Makoto

    1985-01-01

    This paper presents a mathematical theory of analogy, which should be a basis in developing analogical reasoning by a computer. The analogy is a partial identity between two sets of facts. In order to compare several analogies, we introduce an ordering of analogies, and we define two types of optimal analogies, maximal analogies and greatest ones. We show a condition under which the greatest analogy exists, and also present a top-down procedure to find the maximal analogies.

  10. Radiation Evaluation and Concept Development for Analog Probability Processing Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We will perform lab bench evaluations using Analog Devices Lyric Labs evaluation hardware as well as the NASA/GSFC Radiation Effects and Analysis Group...

  11. Development of superconducting bandpass delta-sigma analog-to-digital converter

    Science.gov (United States)

    Bulzacchelli, John F.; Lee, Hae-Seung; Misewich, James A.; Ketchen, Mark B.

    2004-10-01

    This paper recounts the development of a superconducting bandpass delta-sigma (ΔΣ) modulator for direct analog-to-digital conversion of radio frequency signals in the GHz range. The modulator design benefits from several advantages of superconducting electronics: high-Q resonators, fast Josephson comparators, naturally quantized single flux quantum pulses, and high circuit sensitivity. The measured center frequency (2.23 GHz), sampling rate (up to 45 GHz), dynamic range (greater than 57 dB over a 19.6 MHz bandwidth), and input sensitivity (-17.4 dBm full-scale) of the bandpass modulator are the highest reported to date in any technology. The SNR (49 dB over a 20.8 MHz bandwidth) is limited by the frequency resolution of the measurement but still exceeds the SNRs of semiconductor modulators with comparable center frequencies. The design of the modulator test chip and the high speed testing methodology are reviewed. Finally, the paper examines the prospects for improved performance with more advanced modulator architectures.

  12. Development of superconducting bandpass delta-sigma analog-to-digital converter

    Energy Technology Data Exchange (ETDEWEB)

    Bulzacchelli, John F.; Lee, Hae-Seung; Misewich, James A.; Ketchen, Mark

    2004-10-01

    This paper recounts the development of a superconducting bandpass delta-sigma ({delta}{sigma}) modulator for direct analog-to-digital conversion of radio frequency signals in the GHz range. The modulator design benefits from several advantages of superconducting electronics: high-Q resonators, fast Josephson comparators, naturally quantized single flux quantum pulses, and high circuit sensitivity. The measured center frequency (2.23 GHz), sampling rate (up to 45 GHz), dynamic range (greater than 57 dB over a 19.6 MHz bandwidth), and input sensitivity (-17.4 dBm full-scale) of the bandpass modulator are the highest reported to date in any technology. The SNR (49 dB over a 20.8 MHz bandwidth) is limited by the frequency resolution of the measurement but still exceeds the SNRs of semiconductor modulators with comparable center frequencies. The design of the modulator test chip and the high speed testing methodology are reviewed. Finally, the paper examines the prospects for improved performance with more advanced modulator architectures.

  13. Development of an Analog System to Simulate Interface Formation During Fusion™ Casting

    Science.gov (United States)

    Di Ciano, Massimo; Weckman, D. C.; Wells, M. A.

    2016-04-01

    To improve casting and product yields of Fusion™ cast AA3003-core/AA4045-clad laminate ingots, a fundamental understanding of the wetting and interface formation process between the oxidized AA3003 cast surface and the AA4045 melt is required. In this study, a laboratory scale analog/immersion test was developed which mimics the wetting and interface formation process that occurs during Fusion™ casting. The effects of reheating and remelting of the AA3003 cast surface, the degree of surface oxidation present during initial contact of the two alloys, and the atmospheric conditions (air or argon) on interface formation when dipped into an AA4045 melt were examined. Results indicated that in an argon atmosphere, wetting and dissolution of the solid, oxidized AA3003 samples by liquid AA4045 occurred at temperatures both above and below the measured onset of AA3003 remelting. AA3003/AA4045 interfaces were similar to those produced during Fusion™ casting, with a thin layer of AA4045 forming an oxide-free, metallurgical interface to the AA3003 after immersion. The AA3003 surface oxides were not an impediment to wetting and bond formation. Mg surface segregation was observed on the oxidized AA3003 surfaces and may play a role to help penetrate the oxide layer. For tests conducted in air, wetting of the sample by AA4045 liquid was generally poor regardless of temperature.

  14. Development and psychometric testing of a visual analog scale for dental fluorosis

    Directory of Open Access Journals (Sweden)

    R Ramya

    2014-01-01

    Full Text Available Objectives: The aim was to develop and psychometrically test a visual analog scale (VAS for dental fluorosis. Materials and Methods: In a cross-sectional study, esthetic perceptions of varying severities of fluorosis in permanent maxillary incisor teeth presented in 36 photographs were graded on a 10 cm VAS by two groups - an expert panel of dental specialists and lay group comprising 1 st year dental students. The photographs were also graded using Thylstrup-Fejerskov index (TFI. Inter and intra-examiner reliability testing and comparison of specialists′ and 1 st year students′ perceptions were made using intra-class correlation coefficient (ICC. Mean VAS values were validated against TFI scores using Spearman correlation coefficient. Results: A VAS for dental fluorosis was constructed with the help of mean values of subjective ratings for each of the photographs. Inter-rater reliability was found to be moderate (ICC = 0.59. The intra-rater reliability for both the lay group (ICC range: 0.91-0.98 and dental specialists′ group (ICC range: 0.87-0.98 was found to be excellent. High correlation was obtained between lay group′s and dental specialists′ perception of fluorosis on VAS (r = 0.93. VAS scores correlated moderately with TFI scores for the photographs (Spearman′s ρ = 0.725. All the findings were found to be statistically significant (P < 0.05. Conclusion: The developed VAS was found to be a valid and reliable tool to assess dental fluorosis. Validation of the scale on a larger sample from the general population is recommended before it is applied in clinical and epidemiological settings.

  15. Analogy in CLAM

    OpenAIRE

    Melis, Erica

    1999-01-01

    CL A M is a proof planner, developed by the Dream group in Edinburgh,that mainly operates for inductive proofs. This paper addresses the questionhow an analogy model that I developed independently of CL A M can beapplied to CL A M and it presents analogy-driven proof plan construction as acontrol strategy of CL A M . This strategy is realized as a derivational analogythat includes the reformulation of proof plans. The analogical replay checkswhether the reformulated justifications of the sour...

  16. Development of mimetic analogs of pyrokinin-like neuropeptides to disrupt pest insect physiology/behavior

    Science.gov (United States)

    Pyrokinin (FXPRLamide) neuropeptides regulate a variety of critical processes and behaviors in insects, though they are unsuitable as tools to arthropod endocrinologists and/or as pest management agents due to sub-optimal biostability and/or bioavailability characteristics. Peptidomimetic analogs c...

  17. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  18. A field-programmable analog array development platform for vestibular prosthesis signal processing.

    Science.gov (United States)

    Töreyin, Hakan; Bhatti, Pamela

    2013-06-01

    We report on a vestibular prosthesis signal processor realized using an experimental field programmable analog array (FPAA). Completing signal processing functions in the analog domain, the processor is designed to help replace a malfunctioning inner ear sensory organ, a semicircular canal. Relying on angular head motion detected by an inertial sensor, the signal processor maps angular velocity into meaningful control signals to drive a current stimulator. To demonstrate biphasic pulse control a 1 k Ω resistive load was placed across an H-bridge circuit. When connected to a 2.4 V supply, a biphasic current of 100 μA was maintained at stimulation frequencies from 50-350 Hz, pulsewidths from 25-400 μ sec, and interphase gaps ranging from 25-250 μsec.

  19. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  20. Development of an analytical methodology using Fourier transform mass spectrometry to discover new structural analogs of wine natural sweeteners.

    Science.gov (United States)

    Marchal, Axel; Génin, Eric; Waffo-Téguo, Pierre; Bibès, Alice; Da Costa, Grégory; Mérillon, Jean-Michel; Dubourdieu, Denis

    2015-01-01

    Volatile and non-volatile molecules are directly responsible for the thrill and excitement provided by wine-tasting. Their elucidation requires powerful analytical techniques and innovative methodologies. In a recent work, two novel sweet compounds called quercotriterpenosides (QTT) were identified in oak wood used for wine-ageing. The aim of the present study is to discover structural analogs of such natural sweeteners in oak wood. For this purpose, an analytical approach was developed as an alternative to chemical synthesis. Orbitrap mass spectrometry proved to be a crucial technique both to demonstrate the presence of QTT analogs in oak wood by targeted screening and to guide the purification pathway of these molecules using complementary chromatographic tools. Four compounds were isolated and identified for the first time: two isomers, one glucosyl derivative and one galloyl derivative of QTT. Their tasting showed that only the two new isomers were sweet, thus demonstrating both the pertinence of the strategy and the influence of functional groups on gustatory properties. Finally, this paper presents some developments involving multistage Fourier transform mass spectrometry (FTMS) to provide solid structural information on these functional groups prior to any purification of compounds. Such analytical developments could be particularly useful for research on taste-active or bio-active products.

  1. Identification of expressed resistance gene analogs (RGA and development of RGA-SSR markers in tobacco

    Directory of Open Access Journals (Sweden)

    Yuan Qinghua

    2015-01-01

    Full Text Available Tobacco is an important cash crop and an ideal experimental system for studies of plant-pathogen interactions. Identification of tobacco resistance (R genes and resistance gene analogs (RGAs is propitious to elucidate the underlying resistant mechanisms. In recent years, the public tobacco EST (expressed sequence tags data set, which provides a rich source for identifying expressed RGAs, has enlarged substantially. In this study, 149606 Uni-ESTs were assembled from 412325 tobacco ESTs available in GenBank, scanned with 112 published plant R-genes protein sequences, and 1113 Nicotiana (tobacco RGAs (NtRGAs were identified. The majority of them comprised the common R-genes domains, such as NBS-LRR, LRR-PK, LRR, PK and Mlo, while we were unable to identify 109 RGAs using published domains of R-genes. Upon sequence alignment, 1079 NtRGAs were allocated on 712 loci within the Nicotiana benthamiana genome. A total of 78 simple sequence repeats (SSRs were identified from 72 NtRGAs, and out of 64 newly designed primer pairs, 54 primer pairs generated clear bands upon PCR amplification using tobacco genomic DNA. Only nine primer pairs displayed polymorphism in 24 varieties of tobacco, with 2-4 alleles per locus (2.56 alleles on average, while 41 primer pairs were able to detect polymorphisms in six wild species of genus Nicotiana, with 2-4 alleles per locus (2.61 alleles on average.

  2. A prospective examination of risk factors in the development of intrusions following a trauma analog.

    Science.gov (United States)

    Ripley, Adam J; Clapp, Joshua D; Beck, J Gayle

    2017-07-01

    Several factors have been linked to the severity of posttraumatic distress, although retrospective designs in much of the literature limit conclusions regarding the temporal relation between risk factors and corresponding symptoms. To address these concerns, the current project employed an analog trauma paradigm to assess the impact of background characteristics, stress response, and post-stressor affect regulation on subjective distress and intrusive memories experienced during the subsequent processing of emotional stimuli. University students (N = 184; 56% female, 42% White/Non-Hispanic) were shown graphic scenes of a televised suicide. Physiological activation was recorded during exposure with emotion ratings collected following the film. Participants then viewed a sadness- or humor-eliciting prime under instructions to inhibit or naturally express emotion. Intrusions experienced during the priming film and residual distress at study's conclusion were rated prior to debriefing. Hierarchical regression identified reductions in emotional valence as a robust predictor of intrusions and distress. Sympathetic activation and exposure to the sadness prime were associated with intrusion frequency, whereas attenuated parasympathetic response predicted intrusion intensity. Expressive inhibition demonstrated a unique association with residual distress. Results suggest peritraumatic processes and post-exposure factors may hold more prominent relations with immediate trauma-related distress as compared to pre-existing survivor characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The effects of tact training on the development of analogical reasoning.

    Science.gov (United States)

    Miguel, Caio F; Frampton, Sarah E; Lantaya, Charisse A; LaFrance, Danielle L; Quah, Kelly; Meyer, Careen S; Elias, Nassim C; Fernand, Jonathan K

    2015-09-01

    This study assessed whether tact training would establish analogies as measured by equivalence-equivalence relations. In Experiment 1, six college students were trained to tact "same" or "different" in the presence of AB and BC compounds based on component class membership (e.g., A1B1 as "same", and A1B2 as "different"), and then tested on emergent tacts (BA, CB, AC, CA) and equivalence-equivalence relations. Only one of six participants passed all tests without remedial training. In Experiment 2, six college students were trained to tact only compounds belonging to the same class as "same". Three of six participants passed all tests without remedial training. In Experiment 3, six college students were trained to tact stimuli belonging to the same class with a common name prior to exposure to relational tact training. All participants passed tests without remedial training. In Experiment 4, eight college students were trained to tact stimuli belonging to the same class with a common name. Six participants passed without remedial training, while two, who did not tact the relation of the compounds, did not. Results from these studies suggest that simple discrimination of individual components and their relation in the form of tacts is related with equivalence performance. © Society for the Experimental Analysis of Behavior.

  4. Α-amino-β-fluorocyclopropanecarboxylic acids as a new tool for drug development: synthesis of glutamic acid analogs and agonist activity towards metabotropic glutamate receptor 4.

    Science.gov (United States)

    Lemonnier, Gérald; Lion, Cédric; Quirion, Jean-Charles; Pin, Jean-Philippe; Goudet, Cyril; Jubault, Philippe

    2012-08-01

    Herein we describe the diastereoselective synthesis of glutamic acid analogs and the evaluation of their agonist activity towards metabotropic glutamate receptor subtype 4 (mGluR4). These analogs are based on a monofluorinated cyclopropane core substituted with an α-aminoacid function. The potential of this new building block as a tool for the development of a novel class of drugs is demonstrated with racemic analog 11a that displayed the best agonist activity with an EC50 of 340 nM.

  5. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  6. Development of molecular docking-based binding energy to predict the joint effect of BPA and its analogs.

    Science.gov (United States)

    Zhang, Hong-Chang; Hu, Xia-Lin; Yin, Da-Qiang; Lin, Zhi-Fen

    2011-04-01

    A general proposal for predicting the joint effect of endocrine disrupting chemicals by examining binding energy models was developed in this study. 2,2-bis(4-hydroxyphenyl)propane (BPA) and 11 of its analogs were chosen, and the estrogenic activity of each compound was measured by determining its EC50 value using a recombinant gene yeast assay. Binding energies (BEs) were calculated using Surflex-Docking software. The analysis of the relationship between EC50 values and BEs showed that there is a linear correlation between the BEs and EC50 values. Furthermore, the analysis of the given binary and quaternary mixtures of BPA and three of its analogs showed that the joint effects of the mixtures were affected by the proportions of the chemicals in each mixture and their relative binding energy. The correlation between the joint effects of mixtures and the binding energy of the individual compounds has been described using one formula, which can be used to predict the joint effects of other mixtures.

  7. Synthesis of Paclitaxel Analogs

    OpenAIRE

    Xu, Zhibing

    2010-01-01

    Paclitaxel is one of the most successful anti-cancer drugs, particularly in the treatment of breast cancer and ovarian cancer. For the investigation of the interaction between paclitaxel and MD-2 protein, and development of new antagonists for lipopolysaccharide, several C10 A-nor-paclitaxel analogs have been synthesized and their biological activities have been evaluated. In order to reduce the myelosuppression effect of the paclitaxel, several C3â ² and C4 paclitaxel analogs have been synth...

  8. A synthetic combinatorial strategy for developing a-conotoxin analogs as potent a7 nicotinic acetylcholine receptor antagonists

    DEFF Research Database (Denmark)

    Armishaw, Christopher J; Singh, Narender; Medina-Franco, Jose L;

    2010-01-01

    ) nAChR Fluo-4/Ca2+ assay, allowing amino acids that confer antagonistic activity for this receptor to be identified. A second series of individual alpha-conotoxin analogs based on the combinations of defined active amino acid residues from positional scan synthetic combinatorial library screening...... data were synthesized. Several analogs exhibited significantly improved antagonist activity for the alpha(7) nAChR compared with WT-ImI. Binding interactions between the analogs and the alpha(7) nAChR were explored using a homology model of the amino-terminal domain based on a crystal structure...... of an acetylcholine-binding protein. Finally, a third series of refined analogs was synthesized based on modeling studies, which led to several analogs with refined pharmacological properties. Of the 96 individual alpha-conotoxin analogs synthesized, three displayed > or =10-fold increases in antagonist potency...

  9. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  10. Analogical scaffolding: Making meaning in physics through representation and analogy

    Science.gov (United States)

    Podolefsky, Noah Solomon

    This work reviews the literature on analogy, introduces a new model of analogy, and presents a series of experiments that test and confirm the utility of this model to describe and predict student learning in physics with analogy. Pilot studies demonstrate that representations (e.g., diagrams) can play a key role in students' use of analogy. A new model of analogy, Analogical Scaffolding, is developed to explain these initial empirical results. This model will be described in detail, and then applied to describe and predict the outcomes of further experiments. Two large-scale (N>100) studies will demonstrate that: (1) students taught with analogies, according to the Analogical Scaffolding model, outperform students taught without analogies on pre-post assessments focused on electromagnetic waves; (2) the representational forms used to teach with analogy can play a significant role in student learning, with students in one treatment group outperforming students in other treatment groups by factors of two or three. It will be demonstrated that Analogical Scaffolding can be used to predict these results, as well as finer-grained results such as the types of distracters students choose in different treatment groups, and to describe and analyze student reasoning in interviews. Abstraction in physics is reconsidered using Analogical Scaffolding. An operational definition of abstraction is developed within the Analogical Scaffolding framework and employed to explain (a) why physicists consider some ideas more abstract than others in physics, and (b) how students conceptions of these ideas can be modeled. This new approach to abstraction suggests novel approaches to curriculum design in physics using Analogical Scaffolding.

  11. Analogies in optics and micro electronics selected contributions on recent developments

    CERN Document Server

    Lenstra, Daan

    1990-01-01

    This book gives an account of a number of recent developments in two different subfields of research, optics and micro--electronics. The leading principle in presenting them together in one book is the striking similarity between a variety of notions in these two research areas. We mention in this respect tunneling, quantum interference and localization, which are important concepts in quantummechanics and more specifically in condensed matter physics. Miniaturization in solid state engineering has led to new phenomena in which these concepts play their significant roles. As it is the wave character of electrons which is strongly emphasized in these phenomena one's attention is quite naturally directed to the field of optics in which the above quantum-mechanical notions all seem to have their direct classical wavemechanical counterparts. Both micro--electronics and optics have been and still are in a mode of intensifying activity. The possibilities to technically "translate" devices developed within one resea...

  12. Recent developments in studies of l-stepholidine and its analogs: chemistry, pharmacology and clinical implications.

    Science.gov (United States)

    Mo, Jiao; Guo, Yang; Yang, Yu-She; Shen, Jing-Shan; Jin, Guo-Zhang; Zhen, Xuechu

    2007-01-01

    Tetrahydroprotoberberines (THPBs) represent a series of compounds extracted from the Chinese herb Corydalis ambigua and various species of Stephania. THPBs, dependent on the presence of hydroxyl groups in its structure, are divided into three types: nonhydroxyl-THPBs, monohydroxyl-THPBs and dihydroxyl-THPBs. THPBs are identified as a new category of dopamine receptor ligands. Among all THPBs, dihydroxyl-THPBs attracted particular attention because of their dual actions on dopamine (DA) receptors. They exhibit D(1) receptor agonistic activity while acting as D(2) receptor antagonists. This unique pharmacological profile made dihydroxyl-THPBs such as l-stepholidine (l-SPD) potential agents in the treatment of drug addiction, Parkinson's disease, and especially, schizophrenia. Clinical studies have shown that co-administration of l-SPD with a typical antipsychotic drug significantly enhances the therapeutic effects and remarkably reduces the tardive dyskinesia induced by the typical antipsychotic drug used with schizophrenic patients. Moreover, l-SPD alone was shown to have therapeutic value without inducing significant extrapyramidal side effects and also seemed to reduce the negative symptoms of schizophrenia. This is confirmed in experimental studies using animal models of schizophrenia, in which l-SPD improved social interaction and cognitive function, inhibited hyperactivity in schizophrenic animals. This review discusses the chemistry, pharmacology and clinical implications of l-THPBs in the drug development for psychosis and neurobiological diseases.

  13. The role of nucleotides in augmentation of lymphocyte locomotion: Adaptional countermeasure development in microgravity analog environments

    Science.gov (United States)

    Sundaresan, Alamelu; Kulkarni, Anil D.; Yamauchi, Keiko; Pellis, Neal R.

    2006-09-01

    Space travel and long-term space residence such as envisaged in the exploration era implicates burdens on the immune system. An optimal immune response is required to countered and with-stand exposure to pathogens. Countermeasure development is an important avenue in space research especially for long-term space exploration. Microgravity exposure causes detrimental effects in lymphocyte functions which may impair immune response. Impaired lymphocyte function can be remedied by bypassing cell membrane events. This is done by using compounds such as Phorbol Myristate Acetate (PMA). Since activation in mouse splenocytes was augmented using nucleotides, it was essential to observe their effects on human lymphocyte locomotion. A nucleotide/nucleoside (NT/NT) mixture from Otsuka Pharmaceuticals (Naruto, Japan) was used at recommended doses. In lymphocytes cultured in modeled microgravity, the NT/NT mixture used orchestrated locomotion recovery by more than 87%, similar to the response documented with PMA in lymphocytes. Both 12µM and 120µM doses worked similarly. These are preliminary results leading to the possible use of the NT/NT mixture to mitigate immune suppression in micro-gravity. More studies in this direction are required to delineate the role of NT/NT on the immune response in microgravity.

  14. [Distribution of emm genotypes and antibiotic susceptibility of Streptococcus pyogenes strains: analogy with the vaccine in development].

    Science.gov (United States)

    Arslan, Uğur; Oryaşın, Erman; Eskin, Zeynep; Türk Dağı, Hatice; Fındık, Duygu; Tuncer, Inci; Bozdoğan, Bülent

    2013-04-01

    Streptococcus pyogenes is the most common bacterial pathogen causing pharyngotonsillitis, and also can lead to diseases such as otitis media, impetigo, necrotizing fasciitis, bacteremia, sepsis and toxic shock-like syndrome. M protein encoded by emm gene is an important virulence factor of S.pyogenes and it is used for genotyping in epidemiological studies. The aims of this study were to determine the M protein types of group A streptococci (GAS) by using emm gene sequence analysis method, to compare the M types in terms of analogy with the vaccine in development and to determine the antibiotic susceptibilities of the isolates. A total of 35 GAS strains isolated from various clinical specimens in our laboratory were included in the study. Strains growing in blood culture were considered as invasive, strains growing in throat and abscess cultures were considered as non-invasive. The isolates have been identified by conventional methods and 16S rRNA sequence analysis at species level. emm genotyping of strains identified as S.pyogenes, was performed by PCR method as proposed by the CDC. Amplicons were obtained and sequenced in 23 out of 35 isolates. The results were compared with CDC emm sequence database. Antibiotic susceptibility of the isolates was performed by agar dilution method and evaluated as recommended by CLSI. Twenty-three out of 35 isolates could be typed and 15 different emm genotypes were detected. The most common emm types were emm1 (22%), emm89 (13%), emm18 (9%) and emm19 (9%). The detection rate of other emm types (emm5, 12, 14, 17, 26, 29, 37, 74, 78, 92, 99) was 47%. Types emm1, 12, 19, 74, 89 and 99 were observed in strains isolated from blood cultures. It was detected that nine of the 15 (60%) emm types are within the contents of 26 valent vaccine (emm 1, 5, 12, 14, 18, 19, 29, 89, 92). It was also observed that 17 (74%) of the 23 cases were infected by vaccine types and the four emm types (emm1, 12, 19, 89) identified in blood samples were

  15. Developing the enzyme-machine analogy: a non-mathematical approach to teaching Michaelis-Menten kinetics

    Directory of Open Access Journals (Sweden)

    Simon Brown

    2010-06-01

    Full Text Available The behavior of enzyme-catalyzed reactions is not made clear to many students by the standard mathematical description of enzyme kinetics. An enzyme-machine analogy is described that has made the details of the Michaelis-Menten mechanism and the associated kinetics more accessible with minimal use of mathematics. Students taught using the analogy appear to have fewer of the misconceptions than those taught using a more mathematical approach.

  16. Developing the enzyme-machine analogy: a non-mathematical approach to teaching Michaelis-Menten kinetics

    OpenAIRE

    Simon Brown

    2010-01-01

    The behavior of enzyme-catalyzed reactions is not made clear to many students by the standard mathematical description of enzyme kinetics. An enzyme-machine analogy is described that has made the details of the Michaelis-Menten mechanism and the associated kinetics more accessible with minimal use of mathematics. Students taught using the analogy appear to have fewer of the misconceptions than those taught using a more mathematical approach.

  17. Structure and pharmaceutical formulation development of a new long-acting recombinant human insulin analog studied by NMR and MS.

    Science.gov (United States)

    Bednarek, Elżbieta; Sitkowski, Jerzy; Bocian, Wojciech; Borowicz, Piotr; Płucienniczak, Grażyna; Stadnik, Dorota; Surmacz-Chwedoruk, Weronika; Jaworska, Beata; Kozerski, Lech

    2017-02-20

    A monomer structure of a novel human insulin analog A22(S)-B3(K)-B31(R) (SK3R) has been characterized by NMR in water/acetonitrile solution and compared with the structure of human insulin (HIS) established in the same medium. The composition of the oligomer ensemble for neat insulins in water was qualitatively assessed by monitoring, derived from NMR experiment, translational diffusion coefficient Dix10(-10)m(2)s(-1), whose value is a population averaged of individual coefficients for species in oligomeric ensemble. Nanospray ESI/MS experiment was used to establish the masses of oligomers in pharmaceutical formulation of the SK3R insulin. The pharmacodynamic data were established and compared to insulin glargine characterized by the same profile of action in diabetics. The oligomerization process of insulin during development of pharmaceutical formulation with routinely used excipients has been studied using translation diffusion coefficient Dix10(-10)m(2)s(-1) established in water solution. These properties were compared with those of human insulin (HIS) which is a standard reference for novel recombinant insulins. Copyright © 2016. Published by Elsevier B.V.

  18. Origin and development of theater-headed valleys in the Atacama Desert, northern Chile: Morphological analogs to martian valley networks

    Science.gov (United States)

    Irwin, Rossman P.; Tooth, Stephen; Craddock, Robert A.; Howard, Alan D.; de Latour, Ana Baptista

    2014-11-01

    Understanding planetary landforms, including the theater-headed valleys (box canyons) of Mars, usually depends on interpreting geological processes from remote-sensing data without ground-based corroboration. Here we investigate the origin and development of two Mars-analog theater-headed valleys in the hyperarid Atacama Desert of northern Chile. Previous workers attributed these valleys to groundwater sapping based on remote imaging, topography, and publications on the local geology. We evaluate groundwater sapping and alternative hypotheses using field observations of characteristic features, strength measurements of strata exposed in headscarps, and estimates of ephemeral flood discharges within the valleys. The headscarps lack evidence of recent or active seepage weathering, such as spring discharge, salt weathering, alcoves, or vegetation. Their welded tuff caprocks have compressive strengths multiple times those of the underlying epiclastic strata. Flood discharge estimates of cubic meters to tens of cubic meters per second, derived using the Manning equation, are consistent with the size of transported clasts and show that the ephemeral streams are geomorphically effective, even in the modern hyperarid climate. We interpret that headscarp retreat in the Quebrada de Quisma is due to ephemeral flood erosion of weak Miocene epiclastic strata beneath a strong welded tuff, with erosion of the tuff facilitated by vertical jointing. The Quebrada de Humayani headscarp is interpreted as the scar of a giant landslide, maintained against substantial later degradation by similar strong-over-weak stratigraphy. This work suggests that theater-headed valleys on Earth and Mars should not be attributed by default to groundwater sapping, as other processes with lithologic and structural influences can form theater headscarps.

  19. Modelling and quantification of the thermoregulatory responses of the developing avian embryo: electrical analogies of a physiological system.

    Science.gov (United States)

    Youssef, Ali; Exadaktylos, Vasileios; Berckmans, Daniel

    2014-08-01

    Homeothermic animals, including birds, try to keep their body temperature at a constant level within certain boundaries by using thermoregulatory mechanisms. However, during incubation, the thermoregulatory system of the chicken embryo evolves through different stages from a poikilothermic to a homeothermic system. Hence, the thermal response of the fertile egg to changes in ambient temperature is different from one day to another during the embryonic development. The incubated egg can be considered as a physical (thermal) system, which transfers energy (heat) down a potential gradient (temperature difference). The heat flow between the micro-environment and the eggshell under a thermal driving force (temperature difference) has been studied in the past by using the analogy to the flow of electric charge under an electromotive-force. In this work, the thermal-response of incubated eggs to a step-increase in ambient-air temperature is studied and modelled. It is shown that the incubated egg is reacting as a first-order system between embryonic days ED01 and ED13, while, starting from ED14, the egg is reacting as a second-order system. This extends the existing RC (resistor-capacitor) circuit analogue to an RLC (resistor-inductor-capacitor) circuit analogue at the later stage of incubation. The concept of considering the fertile egg and its surrounding environment as an energy-handling device is introduced in this paper. It is suggested that the thermoregulation of the embryo has a thermal induction-like effect starting from ED14 and increasing gradually till hatching.

  20. Curriculum for development of school-business-shared analog electronics%共享型校企合作模拟电子技术课程开发

    Institute of Scientific and Technical Information of China (English)

    张卫丰

    2012-01-01

    The purpose and significance to develop school-business partnership sharing analog electronics are described, and the design concept provided. According to the innovative concept, project-based teaching of the school-business partnership with analog electronics shared is selected. The principle of the development for school- business sharing curriculum is described. The teaching shows that the development of school-business sharing analog electronics is effective. And the new curriculum development methods prove to be appropriate for vocational higher education.%阐述了共享型校企合作模拟电子技术课程开发的目的与意义,提出了共享型校企合作课程开发的依据,给出了共享型校企合作模拟电子技术课程教学项目,并提出了共享型校企合作课程开发的原则,实践证明,共享型校企合作课程开发效果良好,为高职教育的课程改革提供了有益借鉴。

  1. Six-Degree Head-Down Tilt Bed Rest: Forty Years of Development as a Physiological Analog for Weightlessness

    Science.gov (United States)

    Smith, Jeffrey D.; Cromwell, Ronita L.; Kundrot, Craig E.; Charles, John B.

    2011-01-01

    Early on, bed rest was recognized as a method for inducing many of the physiological changes experienced by spaceflight. Head-down tilt (HDT) bed rest was first introduced as an analog for spaceflight by a Soviet team led by Genin and Kakurin. Their study was performed in 1970 (at -4 degrees) and lasted for 30 days; results were reported in the Russian Journal of Space Biology (Kosmicheskaya Biol. 1972; 6(4): 26-28 & 45-109). The goal was to test physiological countermeasures for cosmonauts who would soon begin month-long missions to the Salyut space station. HDT was chosen to produce a similar sensation of blood flow to the head reported by Soyuz cosmonauts. Over the next decade, other tilt angles were studied and comparisons with spaceflight were made, showing that HDT greater than 4 degrees was superior to horizontal bed rest for modeling acute physiological changes observed in space; but, at higher angles, subjects experienced greater discomfort without clearly improving the physiological comparison to spaceflight. A joint study performed by US and Soviet investigators, in 1979, set the goal of standardization of baseline conditions and chose 6-degrees HDT. This effectively established 6-degree HDT bed rest as the internationally-preferred analog for weightlessness and, since 1990, nearly all further studies have been conducted at 6-degrees HDT. A thorough literature review (1970-2010) revealed 534 primary scientific journal articles which reported results from using HDT as a physiological analog for spaceflight. These studies have ranged from as little as 10 minutes to the longest duration of 370 days. Long-term studies lasting four weeks or more have resulted in over 170 primary research articles. Today, the 6-degree HDT model provides a consistent, thoroughly-tested, ground-based analog for spaceflight and allows the proper scientific controls for rigorous testing of physiological countermeasures; however, all models have their strengths and limits. The 6

  2. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community.

    Science.gov (United States)

    Armstrong, Jenna L; Yost, Michael G; Fenske, Richard A

    2014-09-01

    Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Passive sampling rates (m(3)d(-1)) were determined using calculations using chemical properties, loss of depuration compounds, and calibration with side-by-side active air sampling in a dynamic laboratory exposure chamber and in the field. The effects of temperature, relative humidity, and wind velocity on outdoor sampling rates were examined at 23 sites in Yakima Valley, Washington. Indoor sampling rates were significantly lower than outdoors. Outdoor rates significantly increased with average wind velocity, with high rates (>4m(3)d(-1)) observed above 8ms(-1). In exposure chamber studies, very little oxygen analog was observed on the PUF-PAS, yet substantial amounts chlorpyrifos-oxon and azinphos methyl oxon were measured in outdoor samples. PUF-PAS is a practical and useful alternative to AAS because it results in little artificial transformation to the oxygen analog during sampling, it provides cumulative exposure estimates, and the measured sampling rates were comparable to rates for other SVOCs. It is ideal for community based participatory research due to low subject burden and simple deployment in remote areas.

  3. 一种类C语言编程环境的设计与实现%The Design and Implementation of Development Environment of Analogous-C Language

    Institute of Scientific and Technical Information of China (English)

    曹源

    2011-01-01

    In this paper,analogous-C language development environment is designed for the general educational robot.A set of complete analogous-C language and its grammar specifications are defined and the programming environment is designed.The auxiliary functions,%针对通用型教育机器人,设计了一套类C语言编程环境。定义了一套完整的类C语言及其语法规范,设计了类C语言编程界面,同时,实现了编辑器的语法高亮、自动对齐等辅助功能,具有良好的使用效果。

  4. An Assessment of the Contribution of an Analog Forest as a Sustainable Land-use Ecosystem for the Development of Rural Green Economy in Sri Lanka

    Directory of Open Access Journals (Sweden)

    W.K.D.D. Liyanage

    2013-04-01

    Full Text Available Large scale clearing of natural forests for human settlements as well as in the form of tea, rubberand cinnamon plantations resulted forest fragmentation in most natural ecosystems in the wet zone of SriLanka which posed massive threats to both nature and the humans including the loss of biodiversity,environmental hazards and increasing poverty. This paper discusses about the potential to develop ruralgreen economy as a result of consolidating these agricultural lands into analog forests as a sustainableland use practice. Bangamukande Estate, a man-made analog forest in Galle District was selected for thisassessment. Participatory rural appraisal methods were used to obtain information on resource utilizationby the local community in nearby villages. Secondary data of the long term analog forestry establishmentprogramme were also used for analysis the livelihood changes of the people due to the impacts thissystem. Various interventions had been made to address the issues such as encouraging local farmers tocultivate timber, fruits, spices and medicinal plants, paying them for the environmental services theyrender and enhancing their income through green employment. The introduction of new sustainableagricultural activities such as bee keeping and planting fruits resulted in the production of value addedfarm products and organic fruits to be sold in the market. Through environmental based tourism activitiessuch as providing food and accommodation, eco-guidance, and assisting environmental research, thestakeholders are earning a better income supporting the development of a green economy in the country.

  5. Rubrolides as model for the development of new lactones and their aza analogs as potential photosynthesis inhibitors.

    Science.gov (United States)

    Pereira, Ulisses A; Barbosa, Luiz C A; Demuner, Antônio J; Silva, Antônio A; Bertazzini, Michele; Forlani, Giuseppe

    2015-07-01

    Natural phytotoxins and their synthetic analogs are a potential source of new bioactive compounds for agriculture. Analogs of rubrolides, a class of γ-alkylidene-γ-lactones isolated from different ascidians, have been shown to interfere with the photosynthetic electron-transport chain, yet their activity needs to be improved. With this aim, ten 5-aryl-6-benzyl-4-bromopyridazin-3(2H)-ones were prepared in yields ranging from 44 to 88% by reaction of their correspondent γ-alkylidene-γ-lactones with NH2 NH2 . The structures of these rubrolide analogs were determined by (1) H- and (13) C-NMR, 2D-NMR (COSY and HETCOR), NOE difference, and MS techniques. These compounds were evaluated for their abilities of interfering with the light-driven reduction of ferricyanide by isolated spinach chloroplasts. Lactones with electron-withdrawing substituents in the para-position of the benzylidene ring were the most effective inhibitors. Characterization of the activity of 11b/11b' suggested a mechanism based on the interaction with the plastoquinone binding site of photosystem II. Addition of several compounds to the culture medium of a cyanobacterial model strain was found to inhibit algal growth. However, the relative effectiveness was not consistent with their activity in vitro, suggesting the occurrence of multiple targets and/or detoxyfication mechanisms. Indeed, the compounds showed differential effects on the heterotrophic growth of some crop species, Cucumis sativus and Sorghum bicolor. Pyridazin-3(2H)-ones 12e, 12i, and 12j, which have been found poorly active against the photosynthetic electron transport, were the most effective in inhibiting the growth of some weeds, Ipomoea grandifolia and Brachiaria decumbens, under greenhouse conditions.

  6. Analog and VLSI circuits

    CERN Document Server

    Chen, Wai-Kai

    2009-01-01

    Featuring hundreds of illustrations and references, this book provides the information on analog and VLSI circuits. It focuses on analog integrated circuits, presenting the knowledge on monolithic device models, analog circuit cells, high performance analog circuits, RF communication circuits, and PLL circuits.

  7. The development and demonstration of hybrid programmable attitude control electronics. [with adaptable analog/digital design approach

    Science.gov (United States)

    Smith, L. S.; Kopf, E. H., Jr.

    1974-01-01

    HYPACE provides an adaptable, analog/digital design approach that permits preflight and in-flight accommodation of mission changes, component performance variations, spacecraft changes, etc., through programing. This enabled broad multimission flexibility of application in a cost-effective manner. The HYPACE design, which was demonstrated in breadboard form on a single-axis gas-bearing spacecraft simulation, uses a single control channel to perform the attitude control functions sequentially, thus significantly reducing the number of component parts over hard-wired designs. The success of this effort resulted in the concept being selected for the Mariner/Jupiter/Saturn 1977 spacecraft application.

  8. The development and demonstration of hybrid programmable attitude control electronics. [with adaptable analog/digital design approach

    Science.gov (United States)

    Smith, L. S.; Kopf, E. H., Jr.

    1974-01-01

    HYPACE provides an adaptable, analog/digital design approach that permits preflight and in-flight accommodation of mission changes, component performance variations, spacecraft changes, etc., through programing. This enabled broad multimission flexibility of application in a cost-effective manner. The HYPACE design, which was demonstrated in breadboard form on a single-axis gas-bearing spacecraft simulation, uses a single control channel to perform the attitude control functions sequentially, thus significantly reducing the number of component parts over hard-wired designs. The success of this effort resulted in the concept being selected for the Mariner/Jupiter/Saturn 1977 spacecraft application.

  9. When Gesture Becomes Analogy.

    Science.gov (United States)

    Cooperrider, Kensy; Goldin-Meadow, Susan

    2017-07-01

    Analogy researchers do not often examine gesture, and gesture researchers do not often borrow ideas from the study of analogy. One borrowable idea from the world of analogy is the importance of distinguishing between attributes and relations. Gentner (, ) observed that some metaphors highlight attributes and others highlight relations, and called the latter analogies. Mirroring this logic, we observe that some metaphoric gestures represent attributes and others represent relations, and propose to call the latter analogical gestures. We provide examples of such analogical gestures and show how they relate to the categories of iconic and metaphoric gestures described previously. Analogical gestures represent different types of relations and different degrees of relational complexity, and sometimes cohere into larger analogical models. Treating analogical gestures as a distinct phenomenon prompts new questions and predictions, and illustrates one way that the study of gesture and the study of analogy can be mutually informative. Copyright © 2017 Cognitive Science Society, Inc.

  10. 光学Sigma-Delta模数转换器的研究进展%Research and development of optical sigma-delta analog to digital converter

    Institute of Scientific and Technical Information of China (English)

    周雯; 王目光; 李博

    2012-01-01

    Optical analog to digital conversion techniques have been the developing trend of analog to digital converter(ADC) with high conversion rate and high bit accuracy in recent years. As a kind of optical ADC, optical Sigma-Delta ADC has distinguished advantages such as high conversion accuracy and simple analog circuitry. Basic principle of optical Sigma-Delta ADC is introduced. The structures of several typical optical Sigma-Delta ADCs are described detailedly.Finally the merits and demerits of optical Sigma-Delta ADCs with different structures are summed up.%采用光学模数转换技术已经成为高转换速率、高比特精度模数转换器(ADC)的发展趋势.光学Sigma-Delta ADC作为一种光学ADC,具有转换精度高和模拟电路简单等显著优点.介绍了光学Sigma-Delta ADC的基本原理,详细阐述了几种典型的光学Sigma-Delta ADC的系统结构,对不同结构的光学Sigma-Delta ADC的优缺点进行了归纳总结.

  11. Progress on the development of a detector mounted analog and digital readout system for the ATLAS TRT

    CERN Document Server

    Baxter, C; Dressnandt, N; Gay, C; Lundberg, B; Munar, A; Mayers, G; Newcomer, M; Van Berg, R; Williams, H H

    2004-01-01

    The 430,000 element ATLAS Transition Radiation straw tube Tracker (TRT) is divided into a central barrel tracker consisting of 104,000 axially mounted straws and two radially arranged end caps on either side of the barrel with 160,000 straws each. To achieve a track position resolution of 140 mu m, the front end electronics must operate at a low (2fC) threshold with a time marking capability of ~1ns. Two ASICs, the ASDBLR and DTMROC provide the complete pipelined readout chain. Custom designed FBGA packages for the ASICs provide a small enough outline to be detector mounted and the extensive use of low level differential signals make mounting the analog packages on printed circuit boards directly opposite the 40 MHz digital chips feasible. The readout electronics for the barrel occupies a potentially important part of the active tracker volume and an aggressive effort has been made to make it as compact as possible. Utilizing a single board for both analog and digital ASICS a 0.1 cm /sup 3/ per channel volume...

  12. Learning by Analogy: Discriminating between Potential Analogs

    Science.gov (United States)

    Richland, Lindsey E.; McDonough, Ian M.

    2010-01-01

    The ability to successfully discriminate between multiple potentially relevant source analogs when solving new problems is crucial to proficiency in a mathematics domain. Experimental findings in two different mathematical contexts demonstrate that providing cues to support comparative reasoning during an initial instructional analogy, relative to…

  13. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  14. Application of adaptive design methodology in development of a long-acting glucagon-like peptide-1 analog (dulaglutide): statistical design and simulations.

    Science.gov (United States)

    Skrivanek, Zachary; Berry, Scott; Berry, Don; Chien, Jenny; Geiger, Mary Jane; Anderson, James H; Gaydos, Brenda

    2012-11-01

    Dulaglutide (dula, LY2189265), a long-acting glucagon-like peptide-1 analog, is being developed to treat type 2 diabetes mellitus. To foster the development of dula, we designed a two-stage adaptive, dose-finding, inferentially seamless phase 2/3 study. The Bayesian theoretical framework is used to adaptively randomize patients in stage 1 to 7 dula doses and, at the decision point, to either stop for futility or to select up to 2 dula doses for stage 2. After dose selection, patients continue to be randomized to the selected dula doses or comparator arms. Data from patients assigned the selected doses will be pooled across both stages and analyzed with an analysis of covariance model, using baseline hemoglobin A1c and country as covariates. The operating characteristics of the trial were assessed by extensive simulation studies. Simulations demonstrated that the adaptive design would identify the correct doses 88% of the time, compared to as low as 6% for a fixed-dose design (the latter value based on frequentist decision rules analogous to the Bayesian decision rules for adaptive design). This article discusses the decision rules used to select the dula dose(s); the mathematical details of the adaptive algorithm-including a description of the clinical utility index used to mathematically quantify the desirability of a dose based on safety and efficacy measurements; and a description of the simulation process and results that quantify the operating characteristics of the design. © 2012 Diabetes Technology Society.

  15. Structure-based virtual screening, molecular docking, ADMET and molecular simulations to develop benzoxaborole analogs as potential inhibitor against Leishmania donovani trypanothione reductase.

    Science.gov (United States)

    Pandey, Rajan Kumar; Kumbhar, Bajarang Vasant; Sundar, Shyam; Kunwar, Ambarish; Prajapati, Vijay Kumar

    2017-02-01

    Visceral leishmaniasis (VL) is the most fatal form of leishmaniasis and it affects 70 countries worldwide. Increasing drug resistant for antileishmanial drugs such as miltefosine, sodium stibogluconate and pentamidine has been reported in the VL endemic region. Amphotericin B has shown potential antileishmanial activity in different formulations but its cost of treatment and associated nephrotoxicity have limited its use by affected people living in the endemic zone. To control the VL infection in the affected countries, it is necessary to develop new antileishmanial compounds with high efficacy and negligible toxicity. Computer aided programs such as binding free energy estimation; ADMET prediction and molecular dynamics simulation can be used to investigate novel antileishmanial molecules in shorter duration. To develop antileishmanial lead molecule, we performed standard precision (SP) docking for 1160 benzoxaborole analogs along with reference inhibitors against trypanothione reductase of Leishmania parasite. Furthermore, extra precision (XP) docking, ADMET prediction, prime MM-GBSA was conducted over 115 ligands, showing better docking score than reference inhibitors to get potential antileishmanial compounds. Simultaneously, area under the curve (AUC) was estimated using ROC plot to validate the SP and XP docking protocol. Later on, two benzoxaborole analogs with best MM-GBSA ΔG-bind were subjected to molecular simulation and docking confirmation to ensure the ligand interaction with TR. The presented drug discovery based on computational study confirms that BOB27 can be used as a potential drug candidate and warrants further experimental investigation to fight against VL in endemic areas.

  16. A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

    Directory of Open Access Journals (Sweden)

    Pierre Tchakoua

    2015-09-01

    Full Text Available Models are crucial in the engineering design process because they can be used for both the optimization of design parameters and the prediction of performance. Thus, models can significantly reduce design, development and optimization costs. This paper proposes a novel equivalent electrical model for Darrieus-type vertical axis wind turbines (DTVAWTs. The proposed model was built from the mechanical description given by the Paraschivoiu double-multiple streamtube model and is based on the analogy between mechanical and electrical circuits. This work addresses the physical concepts and theoretical formulations underpinning the development of the model. After highlighting the working principle of the DTVAWT, the step-by-step development of the model is presented. For assessment purposes, simulations of aerodynamic characteristics and those of corresponding electrical components are performed and compared.

  17. Analog and hybrid computing

    CERN Document Server

    Hyndman, D E

    2013-01-01

    Analog and Hybrid Computing focuses on the operations of analog and hybrid computers. The book first outlines the history of computing devices that influenced the creation of analog and digital computers. The types of problems to be solved on computers, computing systems, and digital computers are discussed. The text looks at the theory and operation of electronic analog computers, including linear and non-linear computing units and use of analog computers as operational amplifiers. The monograph examines the preparation of problems to be deciphered on computers. Flow diagrams, methods of ampl

  18. Development of high performance Avalanche Photodiodes and dedicated analog systems for HXI/SGD detectors onboard the Astro-H mission

    Science.gov (United States)

    Saito, T.; Nakamori, T.; Yoshino, M.; Mizoma, H.; Kataoka, J.; Kawakami, K.; Yatsu, Y.; Ohno, M.; Goto, K.; Hanabata, Y.; Takahashi, H.; Fukazawa, Y.; Sasano, M.; Torii, S.; Uchiyama, H.; Nakazawa, K.; Makishima, K.; Watanabe, S.; Kokubun, M.; Takahashi, T.; Mori, K.; Tajima, H.; Astro-H HXI/SGD Team

    2013-01-01

    Hard X-ray Imager and Soft Gamma-ray Detector are being developed as onboard instruments for the Astro-H mission, which is scheduled for launch in 2014. In both detectors, BGO scintillators play key roles in achieving high sensitivity in low Earth orbit (LEO), by generating active veto signals to reject cosmic-ray events and gamma-ray backgrounds from radio-activated detector materials. In order to maximize background rejection power, it is also important to minimize the energy threshold of this shield. As a readout sensor of weak scintillation light from a number of BGO crystals in a complicated detector system, high performance, reverse-type Avalanche Photodiodes (APDs), with an effective area of 10×10 mm2 are being employed, instead of bulky photomultiplier tubes (PMTs).Another advantage of using APDs is their low power consumption, although the relatively low gain of APDs (compared to conventional PMTs) requires dedicated analog circuits for noise suppression. In this paper, we report on the development and performance of APD detectors specifically designed for the Astro-H mission. In addition to APD performance, various environmental tests, including radiation hardness and qualification thermal cycling, will be described in detail. Moreover, a dedicated charge sensitive amplifier and analog filters are newly developed and tested here to optimize the performance of APDs to activate fast veto signals within a few μs from the BGO trigger. We will also report on overall performance testing of a prototype BGO detector system that mimics the data acquisition system onboard Astro-H.

  19. All-optical analog comparator

    Science.gov (United States)

    Li, Pu; Yi, Xiaogang; Liu, Xianglian; Zhao, Dongliang; Zhao, Yongpeng; Wang, Yuncai

    2016-08-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function.

  20. All-optical analog comparator

    OpenAIRE

    Pu Li; Xiaogang Yi; Xianglian Liu; Dongliang Zhao; Yongpeng Zhao; Yuncai Wang

    2016-01-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical device...

  1. Analogies of Information Security

    OpenAIRE

    Sole, Amund Bauck

    2016-01-01

    In this thesis it will be tested wither analogies and metaphors would make it easier to teach the fundamental subjects of information security and hacking to people with no previous background in computer science and only basic computer skills. This will be done by conducting interview on people with no background in computer science to see what analogies work the best for different topics in information security. From the analogy getting the best response, a small game will be designed with ...

  2. Potential development and recharge of ground water in Mill Creek Valley, Butler and Hamilton Counties, Ohio, based on analog model analysis

    Science.gov (United States)

    Fidler, Richard E.

    1971-01-01

    Mill Creek valley is part of the greater Cincinnati industrial area in southwestern Ohio. In 1964, nearly 30 percent of the water supply in the study area of about 27 square miles was obtained from wells in the glacial-outwash aquifer underlying the valley. Ground-water demand has increased steadily since the late 1800's, and excessive pumpage during the years of World War II caused water levels to decline to critical levels. Natural recharge to the aquifer, from precipitation, is about 8.5 mgd (million gallons per day). In 1964, the total water use was about 30 mgd, of which 8.1 mgd was obtained from wells in Mill Creek valley, and the remainder was imported from outside the basin. With rapid industrial expansion and population growth, demand for ground water is continuing to increase. By the year 2000 ground-water pumpage is expected to exceed 25 mgd. At a public hearing before the Ohio Water Commission in 1961, artificial recharge of the aquifer through injection wells was proposed as a possible solution to the Mill Creek valley water-supply problem. The present study attempts to determine the feasibility of injection-well recharge systems in the Mill Creek valley. Although basically simple, the hydrologic system in Mill Creek valley is complex in detail and is difficult to evaluate using conventional quantitative methods. Because of this complexity, an electric analog model was used to test specific development plans. Three hypothetical pumping plans were developed by projecting past pumpage data to the years 1980 and 2000. Various combinations of injection wells were tested on the model under different hypothetical conditions of pumpage. Based on analog model analysis, from three to eight inject-ion wells, with an approximate input of 2 mgd each, would reverse the trend in declining groundwater levels and provide adequate water to meet anticipated future demands.

  3. Analog electronics for radiation detection

    CERN Document Server

    2016-01-01

    Analog Electronics for Radiation Detection showcases the latest advances in readout electronics for particle, or radiation, detectors. Featuring chapters written by international experts in their respective fields, this authoritative text: Defines the main design parameters of front-end circuitry developed in microelectronics technologies Explains the basis for the use of complementary metal oxide semiconductor (CMOS) image sensors for the detection of charged particles and other non-consumer applications Delivers an in-depth review of analog-to-digital converters (ADCs), evaluating the pros and cons of ADCs integrated at the pixel, column, and per-chip levels Describes incremental sigma delta ADCs, time-to-digital converter (TDC) architectures, and digital pulse-processing techniques complementary to analog processing Examines the fundamental parameters and front-end types associated with silicon photomultipliers used for single visible-light photon detection Discusses pixel sensors ...

  4. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  5. Geometrical Analogies in Mathematics Lessons

    Science.gov (United States)

    Eid, Wolfram

    2007-01-01

    A typical form of thinking to approach problem solutions humanly is thinking in analogous structures. Therefore school, especially mathematical lessons should help to form and to develop corresponding heuristic abilities of the pupils. In the contribution, a summary of possibilities of mathematics lessons regarding this shall particularly be…

  6. Paper Analogies Enhance Biology Teaching.

    Science.gov (United States)

    Stencel, John E.

    1997-01-01

    Describes how to use paper analogies as models to illustrate various concepts in biology, human anatomy, and physiology classes. Models include biochemical paper models, protein papergrams, a paper model of early brain development, and a 3-D paper model of a eukaryotic cell. (AIM)

  7. Project of the planetary terrain analogs research for technology development and education in geodesy and image processing.

    Science.gov (United States)

    Semenov, Mikhail; Gavrushin, Nikolay; Bataev, Mikhail; Kruzhkov, Maxim; Oberst, Juergen

    2013-04-01

    The MIIGAiK Extraterrestrial Laboratory (MExLab) is currently finalizing the development the robotic mobile science platform MExRover, designed for simulating rover activities on the surface of earth-type planets and satellites. In the project, we develop a hardware and software platform for full rover operation and telemetry processing from onboard instruments, as a means of training undergraduate and postgraduate students and young scientists working in the field of planetary exploration. 1. Introduction The main aim of the project is to provide the research base for image processing development and geodesy survey. Other focus is the development of research programs with participation of students and young scientists of the University, for digital terrain model creation for macro- and microrelief surveying. MExRover would be a bridge from the old soviet Lunokhod experience to the new research base for the future rover technology development support. 2. Rover design The design of the rover and its instrument suite allows acquiring images and navigation data satisfying the requirements for photogrammetric processing. The high-quality color panoramas as well as DTMs (Digital Terrain Models) will be produced aboard and could be used for the real-time track correction and environment analysis. A local operator may control the rover remotely from a distance up to 3 km and continuously monitor all systems. The MExRover has a modular design, which provides maximum flexibility for accomplishing different tasks with different sets of additional equipment weighing up to 15 kg. The framework can be easily disassembled and fit into 3 transport boxes, which allows transporting them on foot, by car, train or plane as a the ordinary luggage. The imaging system included in the present design comprises low resolution video cameras, high resolution stereo camera, microphone and IR camera. More instruments are planned to be installed later as auxiliary equipment, such as

  8. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  9. Challenges in Using Analogies

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same…

  10. An Analog Computer for Electronic Engineering Education

    Science.gov (United States)

    Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

    2011-01-01

    This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

  11. An Analog Computer for Electronic Engineering Education

    Science.gov (United States)

    Fitch, A. L.; Iu, H. H. C.; Lu, D. D. C.

    2011-01-01

    This paper describes a compact analog computer and proposes its use in electronic engineering teaching laboratories to develop student understanding of applications in analog electronics, electronic components, engineering mathematics, control engineering, safe laboratory and workshop practices, circuit construction, testing, and maintenance. The…

  12. Verbal Analogical Reasoning in Children and Adolescents.

    Science.gov (United States)

    Nippold, Marilyn A.

    1986-01-01

    Verbal analogical reasoning tasks are described as potentially valuable in the assessment and management of subtle linguistic defects less easily detected by standardized language tests. Semantic and structural factors that should be considered in the development of verbal analogies as test items are cited, as well as adaptations for nonreaders.…

  13. International Alligator Rivers Analog Project

    Energy Technology Data Exchange (ETDEWEB)

    Bichard, G.F.

    1988-01-01

    The Australian Nuclear Science and Technology Organization (ANSTO), the Japan Atomic Energy Research Institute, the Swedish Nuclear Power Inspectorate, the U.K. Department of the Environment, the US Nuclear Regulatory Commission (NRC), and the Power Reactor and Nuclear Fuel Development Corporation of Japan are participating under the aegis of the Nuclear Energy Agency in the International Alligator Rivers Analog Project. The project has a duration of 3 yr, starting in 1988. The project has grown out of a research program on uranium ore bodies as analogs of high-level waste (HLW) repositories undertaken by ANSTO supported by the NRC. A primary objective of the project is to develop an approach to radionuclide transport model validation that may be used by the participants to support assessments of the safety of radioactive waste repositories. The approach involves integrating mathematical and physical modeling with hydrological and geochemical field and laboratory investigations of the analog site. The Koongarra uranium ore body has been chosen as the analog site because it has a secondary ore body that has formed over the past million years as a result of leaching by groundwater flowing through fractures in the primary ore body.

  14. 3-lead acquisition using single channel ECG device developed on AD8232 analog front end for wireless ECG application

    Science.gov (United States)

    Agung, Mochammad Anugrah; Basari

    2017-02-01

    Electrocardiogram (ECG) devices measure electrical activity of the heart muscle to determine heart conditions. ECG signal quality is the key factor in determining the diseases of the heart. This paper presents the design of 3-lead acquistion on single channel wireless ECG device developed on AD8232 chip platform using microcontroller. To make the system different from others, monopole antenna 2.4 GHz is used in order to send and receive ECG signal. The results show that the system still can receive ECG signal up to 15 meters by line of sight (LOS) condition. The shape of ECG signals is precisely similar with the expected signal, although some delays occur between two consecutive pulses. For further step, the system will be applied with on-body antenna in order to investigate body to body communication that will give variation in connectivity from the others.

  15. Development of a New Radiofluorinated Quinoline Analog for PET Imaging of Phosphodiesterase 5 (PDE5 in Brain

    Directory of Open Access Journals (Sweden)

    Jianrong Liu

    2016-04-01

    Full Text Available Phosphodiesterases (PDEs are enzymes that play a major role in cell signalling by hydrolysing the secondary messengers cyclic adenosine monophosphate (cAMP and/or cyclic guanosine monophosphate (cGMP throughout the body and brain. Altered cyclic nucleotide-mediated signalling has been associated with a wide array of disorders, including neurodegenerative disorders. Recently, PDE5 has been shown to be involved in neurodegenerative disorders such as Alzheimer’s disease, but its precise role has not been elucidated yet. To visualize and quantify the expression of this enzyme in brain, we developed a radiotracer for specific PET imaging of PDE5. A quinoline-based lead compound has been structurally modified resulting in the fluoroethoxymethyl derivative ICF24027 with high inhibitory activity towards PDE5 (IC50 = 1.86 nM. Radiolabelling with fluorine-18 was performed by a one-step nucleophilic substitution reaction using a tosylate precursor (RCY(EOB = 12.9% ± 1.8%; RCP > 99%; SA(EOS = 70–126 GBq/μmol. In vitro autoradiographic studies of [18F]ICF24027 on different mouse tissue as well as on porcine brain slices demonstrated a moderate specific binding to PDE5. In vivo studies in mice revealed that [18F]ICF24027 was metabolized under formation of brain penetrable radiometabolites making the radiotracer unsuitable for PET imaging of PDE5 in brain.

  16. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  17. Challenges in Analogical Reasoning

    CERN Document Server

    Lin, Shih-Yin

    2016-01-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features. One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.

  18. TV Analog Station Transmitters

    Data.gov (United States)

    Department of Homeland Security — This file is an extract from the Consolidated Database System (CDBS) licensed by the Media Bureau. It consists of Analog Television Stations (see Rule Part47 CFR...

  19. Analog multivariate counting analyzers

    CERN Document Server

    Nikitin, A V; Armstrong, T P

    2003-01-01

    Characterizing rates of occurrence of various features of a signal is of great importance in numerous types of physical measurements. Such signal features can be defined as certain discrete coincidence events, e.g. crossings of a signal with a given threshold, or occurrence of extrema of a certain amplitude. We describe measuring rates of such events by means of analog multivariate counting analyzers. Given a continuous scalar or multicomponent (vector) input signal, an analog counting analyzer outputs a continuous signal with the instantaneous magnitude equal to the rate of occurrence of certain coincidence events. The analog nature of the proposed analyzers allows us to reformulate many problems of the traditional counting measurements, and cast them in a form which is readily addressed by methods of differential calculus rather than by algebraic or logical means of digital signal processing. Analog counting analyzers can be easily implemented in discrete or integrated electronic circuits, do not suffer fro...

  20. FGF growth factor analogs

    Science.gov (United States)

    Zamora, Paul O [Gaithersburg, MD; Pena, Louis A [Poquott, NY; Lin, Xinhua [Plainview, NY; Takahashi, Kazuyuki [Germantown, MD

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  1. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  2. Development of low-noise high-speed analog ASIC for X-ray CCD cameras and wide-band X-ray imaging sensors

    Science.gov (United States)

    Nakajima, Hiroshi; Hirose, Shin-nosuke; Imatani, Ritsuko; Nagino, Ryo; Anabuki, Naohisa; Hayashida, Kiyoshi; Tsunemi, Hiroshi; Doty, John P.; Ikeda, Hirokazu; Kitamura, Hisashi; Uchihori, Yukio

    2016-09-01

    We report on the development and performance evaluation of the mixed-signal Application Specific Integrated Circuit (ASIC) developed for the signal processing of onboard X-ray CCD cameras and various types of X-ray imaging sensors in astrophysics. The quick and low-noise readout is essential for the pile-up free imaging spectroscopy with a future X-ray telescope. Our goal is the readout noise of 5e- r . m . s . at the pixel rate of 1 Mpix/s that is about 10 times faster than those of the currently working detectors. We successfully developed a low-noise ASIC as the front-end electronics of the Soft X-ray Imager onboard Hitomi that was launched on February 17, 2016. However, it has two analog-to-digital converters per chain due to the limited processing speed and hence we need to correct the difference of gain to obtain the X-ray spectra. Furthermore, its input equivalent noise performance is not satisfactory (> 100 μV) at the pixel rate higher than 500 kpix/s. Then we upgrade the design of the ASIC with the fourth-order ΔΣ modulators to enhance its inherent noise-shaping performance. Its performance is measured using pseudo CCD signals with variable processing speed. Although its input equivalent noise is comparable with the conventional one, the integrated non-linearity (0.1%) improves to about the half of that of the conventional one. The radiation tolerance is also measured with regard to the total ionizing dose effect and the single event latch-up using protons and Xenon, respectively. The former experiment shows that all of the performances does not change after imposing the dose corresponding to 590 years in a low earth orbit. We also put the upper limit on the frequency of the latch-up to be once per 48 years.

  3. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  4. Analogies in biology textbooks in zoology teaching

    Directory of Open Access Journals (Sweden)

    Saulo Cézar Seiffert Santos

    2011-05-01

    Full Text Available The biologic structures of living creatures are of difficult understanding for students, because they are usually unknown by those, in needs of strategic didactics in order to facilitate the student understanding. There are several strategies and methods for teaching, such as, analogies, metaphors, descriptions, among others. In this article we aim to identify, assess and classify the analogies used in the Higher School Biology textbooks, commonly used in Public State Schools of Manaus – AM, related to the zoology theme. The methodological procedure includes: a analysis of the whole zoological content of the most used textbooks in the public state network of Amazonas throughout the year; b three didactic textbooks have been specifically analyzed in order to specify the class taxon of “Fish” for the comparison of possible variations of types and quantities of analogies. The adopted classification of analogies was of Curtis & Reigeluth (1984 and the model of enriching analysis was according to the TWA Glynn model (Harrison & Treagust, 1993. It has been concluded that the use of analogies is greater in the content of invertebrates than that of vertebrates. Most Analogies are presented in a simple and direct manner, comparing structures, concrete to concrete, and of verbal mediation, almost nothing is presented in a diverse and heuristic manner of Zoology content on the LD. The development of limits of comparison and reflexion about the analogies was rare, only the presentation of the analogue and the target of analogy occurred.

  5. Analog modeling and kinematic restoration of inverted hangingwall synclinal basins developed above syn-kinematic salt: Application to the Lusitanian and Parentis basins

    Science.gov (United States)

    Roma, Maria; Vidal-Royo, Oskar; McClay, Ken; Ferrer, Oriol; Muñoz, Josep Anton

    2017-04-01

    The formation of hagingwall syncline basins is basically constrained by the geometry of the basement-involved fault, but also by salt distribution . The formation of such basins is common around the Iberian Peninsula (e.g. Lusitanian, Parentis, Basque-Cantabian, Cameros and Organyà basins) where Upper Triassic (Keuper) salt governed their polyphasic Mesozoic extension and their subsequent Alpine inversion. In this scenario, a precise interpretation of the sub-salt faults geometry and a reconstruction of the initial salt thickness are key to understand the kinematic evolution of such basins. Using an experimental approach (sandbox models) and these Mesozoic basins as natural analogues, the aim of this work is to: 1) investigate the main parameters that controlled the formation and evolution of hagingwall syncline basins analyzing the role of syn-kinematic salt during extension and subsequent inversion; and 2) quantify the deformation and salt mobilization based on restoration of analog model cross sections. The experimental results demonstrate that premature welds are developed by salt deflation with consequent upward propagation of the basal fault in salt-bearing rift systems with a large amount of extension,. In contrast, thicker salt inhibits the upward fault propagation, which results into a further salt migration and development of a hagingwall syncline basins flanked by salt walls. The inherited extensional architecture as well as salt continuity dramatically controlled subsequent inversion. Shortening initially produced the folding and the uplift of the synclinal basins. Minor reverse faults form as a consequence of overtightening of welded diapir stems. However, no trace of reverse faulting is found around diapirs stems, as ductile unit is still available for extrusion, squeezing and accommodation of shortening. Restoration of the sandbox models has demonstrated that this is a powerful tool to unravel the complex structures in the models and this may

  6. Digital and analog communication systems

    Science.gov (United States)

    Shanmugam, K. S.

    1979-01-01

    The book presents an introductory treatment of digital and analog communication systems with emphasis on digital systems. Attention is given to the following topics: systems and signal analysis, random signal theory, information and channel capacity, baseband data transmission, analog signal transmission, noise in analog communication systems, digital carrier modulation schemes, error control coding, and the digital transmission of analog signals.

  7. Analogical Reasoning in Geometry Education

    Science.gov (United States)

    Magdas, Ioana

    2015-01-01

    The analogical reasoning isn't used only in mathematics but also in everyday life. In this article we approach the analogical reasoning in Geometry Education. The novelty of this article is a classification of geometrical analogies by reasoning type and their exemplification. Our classification includes: analogies for understanding and setting a…

  8. Analysis of non-TIR NBS-LRR resistance gene analogs in Musa acuminata Colla: Isolation, RFLP marker development, and physical mapping

    Directory of Open Access Journals (Sweden)

    Souza Manoel T

    2008-01-01

    Full Text Available Abstract Background Many commercial banana varieties lack sources of resistance to pests and diseases, as a consequence of sterility and narrow genetic background. Fertile wild relatives, by contrast, possess greater variability and represent potential sources of disease resistance genes (R-genes. The largest known family of plant R-genes encode proteins with nucleotide-binding site (NBS and C-terminal leucine-rich repeat (LRR domains. Conserved motifs in such genes in diverse plant species offer a means for isolation of candidate genes in banana which may be involved in plant defence. Results A computational strategy was developed for unbiased conserved motif discovery in NBS and LRR domains in R-genes and homologues in monocotyledonous plant species. Degenerate PCR primers targeting conserved motifs were tested on the wild cultivar Musa acuminata subsp. burmannicoides, var. Calcutta 4, which is resistant to a number of fungal pathogens and nematodes. One hundred and seventy four resistance gene analogs (RGAs were amplified and assembled into 52 contiguous sequences. Motifs present were typical of the non-TIR NBS-LRR RGA subfamily. A phylogenetic analysis of deduced amino-acid sequences for 33 RGAs with contiguous open reading frames (ORFs, together with RGAs from Arabidopsis thaliana and Oryza sativa, grouped most Musa RGAs within monocotyledon-specific clades. RFLP-RGA markers were developed, with 12 displaying distinct polymorphisms in parentals and F1 progeny of a diploid M. acuminata mapping population. Eighty eight BAC clones were identified in M. acuminata Calcutta 4, M. acuminata Grande Naine, and M. balbisiana Pisang Klutuk Wulung BAC libraries when hybridized to two RGA probes. Multiple copy RGAs were common within BAC clones, potentially representing variation reservoirs for evolution of new R-gene specificities. Conclusion This is the first large scale analysis of NBS-LRR RGAs in M. acuminata Calcutta 4. Contig sequences were

  9. Performance of an analog ASIC developed for the front-end electronics of the soft x-ray imager onboard ASTRO-H

    Science.gov (United States)

    Nakajima, H.; Idehara, T.; Matsuura, D.; Anabuki, N.; Tsunemi, H.; Doty, J. P.; Ikeda, H.

    2009-08-01

    We report on the performance of an analog application-specified integrated circuit (ASIC) developed for the front-end electronics of the X-ray CCD camera system (SXI: Soft X-ray Imager) onboard the ASTRO-H satellite. The ASIC consists of four identical channels and they simultaneously process the CCD signals at the pixel rate of 68kHz. Delta-Sigma modulator is adopted to achieve effective noise shaping and obtain a high resolution decimal values with relatively simple circuits. We will implement 16 ASIC chips in total in the focal plane assembly. The results of the unit test shows that it works properly with moderately low input noise of <30μV at the pixel rate of 80kHz. Power consumption is sufficiently low of 150mW. Dynamic range of input signals is +-20mV that covers effective energy range of the CCD chips of SXI (0.2-20keV). The integrated non-linearity of 0.2% satisfies the same performance as the conventional CCD detectors in orbit. The radiation tolerance against total ionizing dose (TID) effect and single event latch-up (SEL) has also been investigated. The irradiation test using 60Co gamma-rays and proton beam showed that the ASIC has sufficient tolerance against TID up to 200 and 167krad respectively, which thoroughly exceeds the expected operating duration in the planned low-inclination low-earth orbit. The irradiation of the Fe ion beam also showed no latch-up nor malfunctions up to the fluence of 4.7x10^7ions. The threshold against SEL is larger than 1.68MeVcm^2/mg, which is sufficiently high enough that SEL events should not be a major cause of instrument downtime.

  10. Diapause hormone in the Helicoverpa/Heliothis complex: A review of gene expression, peptide structure and activity, analog and antagonist development, and the receptor.

    Science.gov (United States)

    Zhang, Qirui; Nachman, Ronald J; Denlinger, David L

    2015-10-01

    This review summarizes recent studies focusing on diapause hormone (DH) in the Helicoverpa/Heliothis complex of agricultural pests. Moths in this complex overwinter in pupal diapause, a form of developmental arrest used to circumvent unfavorable seasons. DH was originally reported in the silkmoth Bombyx mori, a species that relies on DH to induce an embryonic diapause. But, in the case of Helicoverpa/Heliothis, levels of dh transcripts and DH peptides are more abundant in nondiapausing pupae than in diapausing individuals, and DH effectively terminates diapause within a specific temperature range. A structure activity relationship study indicated that the active core of DH is the C-terminal hepta-peptide, LWFGPRLa. We designed and synthesized a first generation of DH agonists and identified two agonists (PK-2Abf and PK-Etz) that were nearly 50- and 13-fold more potent than the native hormone. These studies revealed two structural characteristics of DH and its agonists that are essential for interaction with the receptor: a trans-Pro configuration to form a type I β-turn and a hydrophobic moiety involved in ligand binding. Modification of DH at the active core yielded a potent DH antagonist (DH-Jo, acetyl-GLWA[Jo]RLa) as well as an agonist (DH-2Abf-K). Three compounds (Decyl-1963, Dodecyl-1967, Heptyl-1965) were identified as agents capable of penetrating the cuticle of young pupae and thereby preventing the entry into diapause. DH receptor cDNA was cloned and an effective in vitro high throughput screen system was established for future use. This work sets the stage for further development of DH analogs and antagonists that have the potential to disrupt insect diapause as a tool for pest management.

  11. Advances in Analog Circuit Design 2015

    CERN Document Server

    Baschirotto, Andrea; Harpe, Pieter

    2016-01-01

    This book is based on the 18 tutorials presented during the 24th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of efficient sensor interfaces and low-power RF systems. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development. ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing.

  12. Investigating Quantum Mechanical Tunneling at the Nanoscale via Analogy: Development and Assessment of a Teaching Tool for Upper-Division Chemistry

    Science.gov (United States)

    Muniz, Marc N.; Oliver-Hoyo, Maria T.

    2014-01-01

    We report a novel educational activity designed to teach quantum mechanical tunneling to upper-division undergraduate students in the context of nanochemistry. The activity is based on a theoretical framework for analogy and is split into three parts that are linked pedagogically through the framework: classical ball-and-ramp system, tunneling…

  13. Analogical Learning and Automated Rule Constructions

    Institute of Scientific and Technical Information of China (English)

    周哈阳

    1991-01-01

    This paper describes some experiments of analogical learning and automated rule construction.The present investigation focuses on knowledge acquisition,learning by analyogy,and knowledge retention.The developed system initially learns from scratch,gradually acquires knowledge from its environment through trial-and-error interaction,incrementally augments its knowledge base,and analogically solves new tasks in a more efficient and direct manner.

  14. Are Scientific Analogies Metaphors?

    Science.gov (United States)

    1981-02-01

    psychospiritual processes. A more modern example of unclarified analogy is Freud’s (1973; reprinted from 1955) discussion of anal- eroticism , in which...299-304. Freud, S. On transformations of instinct as exemplified in anal eroticism . In J. Strachey (Ed.), The standard 37 edition of the complete

  15. Analogy, explanation, and proof.

    Science.gov (United States)

    Hummel, John E; Licato, John; Bringsjord, Selmer

    2014-01-01

    People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  16. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  17. Experience in the Development of the CMS Inner Tracker Analog Optohybrid Circuits: Project, Qualification, Volume Production, Quality Assurance and Final Performance

    CERN Document Server

    Ricci, Daniel; Bilei, Gian Mario; Casinini, F; Postolache, Vasile

    2005-01-01

    The Tracker system of the Compact Muon Solenoid (CMS) Experiment, will employ approximately 40,000 analog fibre-optic data and control links. The optical readout system is responsible for converting and transmitting the electrical signals coming out from the front-end to the outside counting room. Concerning the inner part of the Tracker, about 3,600 Analog Optohybrid circuits are involved in this tasks. These circuits have been designed and successfully produced in Italy under the responsibility of INFN Perugia CMS group completing the volume production phase by February 2005. Environmental features, reliability and performances of these circuits have been extensively tested and qualified. This paper reviews the most relevant steps of the manufacturing and quality assurance process: from prototypes to mass-production for the final CMS use.

  18. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  19. Analogy Construction versus Analogy Solution, and Their Influence on Transfer

    Science.gov (United States)

    Harpaz-Itay, Yifat; Kaniel, Shlomo; Ben-Amram, Einat

    2006-01-01

    This study compares transfer performed by subjects trained to solve verbal analogies, with transfer by subjects trained to construct them. The first group (n = 57) received instruction in a strategy to solve verbal analogies and the second group (n = 66) was trained in strategies for constructing such analogies. Before and after intervention, all…

  20. Analogy, Explanation, and Proof

    Directory of Open Access Journals (Sweden)

    John eHummel

    2014-11-01

    Full Text Available People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic whose truth was not even known prior to the existence of the explanation (proof. What do the cognitive operations underlying the (inductive inference that the milk is sour have in common with the (deductive proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This small-seeming difference poses a challenge to the task of marshaling our understanding of analogical reasoning in the service of understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence.

  1. A Transiting Jupiter Analog

    CERN Document Server

    Kipping, David M; Henze, Chris; Teachey, Alex; Isaacson, Howard T; Petigura, Erik A; Marcy, Geoffrey W; Buchhave, Lars A; Chen, Jingjing; Bryson, Steve T; Sandford, Emily

    2016-01-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of $(0.91\\pm0.02)$ $R_{\\mathrm{Jup}}$, a low orbital eccentricity ($0.06_{-0.04}^{+0.10}$) and an equilibrium temperature of $(131\\pm3)$ K, Kepler-167e bears many of the basic hallmarks of Jupiter. Kepler-167e is accompanied by three Super-Earths on compact orbits, which we also validate, leaving a large cavity of transiting worlds around the habitable-zone. With two transits and continuous photometric ...

  2. Inductive, Analogical, and Communicative Generalization

    Directory of Open Access Journals (Sweden)

    Adri Smaling

    2003-03-01

    Full Text Available Three forms of inductive generalization - statistical generalization, variation-based generalization and theory-carried generalization - are insufficient concerning case-to-case generalization, which is a form of analogical generalization. The quality of case-to-case generalization needs to be reinforced by setting up explicit analogical argumentation. To evaluate analogical argumentation six criteria are discussed. Good analogical reasoning is an indispensable support to forms of communicative generalization - receptive and responsive (participative generalization — as well as exemplary generalization.

  3. Unconscious violinists and the use of analogies in moral argument.

    Science.gov (United States)

    Wiland, E

    2000-12-01

    Analogies are the stuff out of which normative moral philosophy is made. Certainly one of the most famous analogies constructed by a philosopher in order to argue for a specific controversial moral conclusion is the one involving Judith Thomson's unconscious violinist. Reflection upon this analogy is meant to show us that abortion is generally not immoral even if the prenatal have the same moral status as the postnatal. This was and still is a controversial conclusion, and yet the analogy does seem to reveal in a very vivid way what makes abortion a reasonable response to a terrible situation. But Thomson's example has frequently been attacked on all sides for not being truly analogous to abortion. Here I develop a brand new analogy that sheds light on the issue with which Thomson was concerned, while at the same time avoiding most of the more serious objections made to her analogy.

  4. El desarrollo de la inferencia analógica en niños que viven en sectores urbanos pobres The development of analogical inference in children living in slums

    Directory of Open Access Journals (Sweden)

    Mariela Orozco-Hormaza

    2012-01-01

    Full Text Available Se describe el desarrollo de la inferencia analógica en 405 niños de 3, 4 y 5 años, que viven en sectores urbanos pobres de las ciudades Colombianas de Cali y Santa Marta. Con este fin, se les propuso individualmente un problema de inferencia analógica. Los resultados muestran que niños de todas las edades son capaces de solucionar el problema utilizando la estrategia que requiere establecer inferencia y relaciones de analogía, aunque el porcentaje de niños de 5 años que la usa es significativamente mayor que el de los otros dos grupos. Los resultados obtenidos permiten discutir dos tendencias en el desarrollo cognitivo: una centrada en la edad y la otra en el variabilidad intra e inter-individual.The development of analogical inference is described through the study of 405 children aged 3, 4 and 5 years old, living in poor urban neighborhoods in two Colombian cities - Cali (204 and Santa Marta (201. In order to accomplish the objective, children were asked to individually solve an inference problem based on analogical relations. Independently of their age, children were able to solve the problem using a strategy that requires establishing inference and analogical relations. Nevertheless, a higher percentage of the 5-year-old children tend to use that strategy more often. The results obtained allow the discussion of two conceptions of development: one focused on the age and the other on intra- and inter-individual variability.

  5. Using Analogies in Teaching Physics: A Study on Latvian Teachers' Views and Experience

    Science.gov (United States)

    Jonane, Lolita

    2015-01-01

    The role of analogies as tools for teaching difficult science concepts has been widely discussed in science education. The application of analogies in the context of sustainable education involves richer potential. The purposeful use of appropriate analogies can facilitate analogical thinking and transfer skills, as well as develop abilities which…

  6. Albert Einstein, Analogizer Extraordinaire

    CERN Document Server

    CERN. Geneva

    2007-01-01

    Where does deep insight in physics come from? It is tempting to think that it comes from the purest and most precise of reasoning, following ironclad laws of thought that compel the clear mind completely rigidly. And yet the truth is quite otherwise. One finds, when one looks closely at any major discovery, that the greatest of physicists are, in some sense, the most crazily daring and irrational of all physicists. Albert Einstein exemplifies this thesis in spades. In this talk I will describe the key role, throughout Albert Einstein's fabulously creative life, played by wild guesses made by analogy lacking any basis whatsoever in pure reasoning. In particular, in this year of 2007, the centenary of 1907, I will describe how over the course of two years (1905 through 1907) of pondering, Einstein slowly came, via analogy, to understand the full, radical consequences of the equation that he had first discovered and published in 1905, arguably the most famous equation of all time: E = mc2.

  7. Analogy, higher order thinking, and education.

    Science.gov (United States)

    Richland, Lindsey Engle; Simms, Nina

    2015-01-01

    Analogical reasoning, the ability to understand phenomena as systems of structured relationships that can be aligned, compared, and mapped together, plays a fundamental role in the technology rich, increasingly globalized educational climate of the 21st century. Flexible, conceptual thinking is prioritized in this view of education, and schools are emphasizing 'higher order thinking', rather than memorization of a cannon of key topics. The lack of a cognitively grounded definition for higher order thinking, however, has led to a field of research and practice with little coherence across domains or connection to the large body of cognitive science research on thinking. We review literature on analogy and disciplinary higher order thinking to propose that relational reasoning can be productively considered the cognitive underpinning of higher order thinking. We highlight the utility of this framework for developing insights into practice through a review of mathematics, science, and history educational contexts. In these disciplines, analogy is essential to developing expert-like disciplinary knowledge in which concepts are understood to be systems of relationships that can be connected and flexibly manipulated. At the same time, analogies in education require explicit support to ensure that learners notice the relevance of relational thinking, have adequate processing resources available to mentally hold and manipulate relations, and are able to recognize both the similarities and differences when drawing analogies between systems of relationships.

  8. Anti-Plasmodium activity of ceramide analogs

    Directory of Open Access Journals (Sweden)

    Gatt Shimon

    2004-12-01

    Full Text Available Abstract Background Sphingolipids are key molecules regulating many essential functions in eukaryotic cells and ceramide plays a central role in sphingolipid metabolism. A sphingolipid metabolism occurs in the intraerythrocytic stages of Plasmodium falciparum and is associated with essential biological processes. It constitutes an attractive and potential target for the development of new antimalarial drugs. Methods The anti-Plasmodium activity of a series of ceramide analogs containing different linkages (amide, methylene or thiourea linkages between the fatty acid part of ceramide and the sphingoid core was investigated in culture and compared to the sphingolipid analog PPMP (d,1-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol. This analog is known to inhibit the parasite sphingomyelin synthase activity and block parasite development by preventing the formation of the tubovesicular network that extends from the parasitophorous vacuole to the red cell membrane and delivers essential extracellular nutrients to the parasite. Results Analogs containing methylene linkage showed a considerably higher anti-Plasmodium activity (IC50 in the low nanomolar range than PPMP and their counterparts with a natural amide linkage (IC50 in the micromolar range. The methylene analogs blocked irreversibly P. falciparum development leading to parasite eradication in contrast to PPMP whose effect is cytostatic. A high sensitivity of action towards the parasite was observed when compared to their effect on the human MRC-5 cell growth. The toxicity towards parasites did not correlate with the inhibition by methylene analogs of the parasite sphingomyelin synthase activity and the tubovesicular network formation, indicating that this enzyme is not their primary target. Conclusions It has been shown that ceramide analogs were potent inhibitors of P. falciparum growth in culture. Interestingly, the nature of the linkage between the fatty acid part and the

  9. Analogical Reasoning in Children with Specific Language Impairment

    Science.gov (United States)

    Leroy, Sandrine; Parisse, Christophe; Maillart, Christelle

    2012-01-01

    Usage-based theory considers analogical reasoning as a cognitive process required in language development. We hypothesized that difficulties with analogical reasoning could hinder the abstraction of construction schemas, thus slowing down morphosyntactic development for children with specific language impairment (SLI). We also hypothesized, in…

  10. Use of an analog site near Raymond, California, to develop equipment and methods for characterizing a potential high-level, nuclear waste repository site at Yucca Mountain, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Umari, A.M.J.; Geldon, A.; Patterson, G.; Gemmell, J.; Earle, J.; Darnell, J. [Geological Survey, Denver, CO (United States)

    1994-12-31

    Yucca Mountain, Nevada, currently is being investigated by the U.S. Geological Survey as a potential site for a high-level nuclear waste repository. Planned hydraulic-stress and tracer tests in fractured, tuffaceous rocks below the water table at Yucca Mountain will require work at depths in excess of 1,300 feet. To facilitate prototype testing of equipment and methods to be used in aquifer tests at Yucca Mountain, an analog site was selected in the foothills of the Sierra Nevada near Raymond, California. Two of nine 250- to 300-feet deep wells drilled into fractured, granitic rocks at the Raymond site have been instrumented with packers, pressure transducers, and other equipment that will be used at Yucca Mountain. Aquifer tests conducted at the Raymond site to date have demonstrated a need to modify some of the equipment and methods conceived for use at Yucca Mountain.

  11. Successfully Engaging Scientists in NASA Education and Public Outreach: Examples from a Teacher Professional Development Workshop Series and a Planetary Analog Festival

    Science.gov (United States)

    Jones, A. P.; Hsu, B. C.; Bleacher, L.; Shaner, A. J.

    2014-12-01

    The Lunar Workshops for Educators are a series of weeklong workshops for grade 6-9 science teachers focused on lunar science and exploration, sponsored by the Lunar Reconnaissance Orbiter (LRO). These workshops have been held across the country for the past five years, in places underserved with respect to NASA workshops and at LRO team member institutions. MarsFest is a planetary analog festival that has been held annually in Death Valley National Park since 2012, made possible with support from the Curiosity (primarily the Sample Analysis at Mars) Education and Public Outreach team, NASA's Ames Research Center, NASA's Goddard Space Flight Center, the SETI Institute, and Death Valley National Park. Both the Lunar Workshops for Educators and MarsFest rely strongly on scientist engagement for their success. In the Lunar Workshops, scientists and engineers give talks for workshop participants, support facility tours and field trips, and, where possible, have lunch with the teachers to interact with them in a less formal setting. Teachers have enthusiastically appreciated and benefited from all of these interactions, and the scientists and engineers also provide positive feedback about their involvement. In MarsFest, scientists and engineers give public presentations and take park visitors on field trips to planetary analog sites. The trips are led by scientists who do research at the field trip sites whenever possible. Surveys of festival participants indicate an appreciation for learning about scientific research being conducted in the park from the people involved in that research, and scientists and engineers report enjoying sharing their work with the public through this program. The key to effective scientist engagement in all of the workshops and festivals has been a close relationship and open communication between the scientists and engineers and the activity facilitators. I will provide more details about both of these programs, how scientists and engineers

  12. Vorticity in analog gravity

    Science.gov (United States)

    Cropp, Bethan; Liberati, Stefano; Turcati, Rodrigo

    2016-06-01

    In the analog gravity framework, the acoustic disturbances in a moving fluid can be described by an equation of motion identical to a relativistic scalar massless field propagating in curved space-time. This description is possible only when the fluid under consideration is barotropic, inviscid, and irrotational. In this case, the propagation of the perturbations is governed by an acoustic metric that depends algebrically on the local speed of sound, density, and the background flow velocity, the latter assumed to be vorticity-free. In this work we provide a straightforward extension in order to go beyond the irrotational constraint. Using a charged—relativistic and nonrelativistic—Bose-Einstein condensate as a physical system, we show that in the low-momentum limit and performing the eikonal approximation we can derive a d’Alembertian equation of motion for the charged phonons where the emergent acoustic metric depends on flow velocity in the presence of vorticity.

  13. NaturAnalogs for the Unsaturated Zone

    Energy Technology Data Exchange (ETDEWEB)

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

    The purpose of this Analysis/Model Report (AMR) is to document natural and anthropogenic (human-induced) analog sites and processes that are applicable to flow and transport processes expected to occur at the potential Yucca Mountain repository in order to build increased confidence in modeling processes of Unsaturated Zone (UZ) flow and transport. This AMR was prepared in accordance with ''AMR Development Plan for U0135, Natural Analogs for the UZ'' (CRWMS 1999a). Knowledge from analog sites and processes is used as corroborating information to test and build confidence in flow and transport models of Yucca Mountain, Nevada. This AMR supports the Unsaturated Zone (UZ) Flow and Transport Process Model Report (PMR) and the Yucca Mountain Site Description. The objectives of this AMR are to test and build confidence in the representation of UZ processes in numerical models utilized in the UZ Flow and Transport Model. This is accomplished by: (1) applying data from Boxy Canyon, Idaho in simulations of UZ flow using the same methodologies incorporated in the Yucca Mountain UZ Flow and Transport Model to assess the fracture-matrix interaction conceptual model; (2) Providing a preliminary basis for analysis of radionuclide transport at Pena Blanca, Mexico as an analog of radionuclide transport at Yucca Mountain; and (3) Synthesizing existing information from natural analog studies to provide corroborating evidence for representation of ambient and thermally coupled UZ flow and transport processes in the UZ Model.

  14. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Directory of Open Access Journals (Sweden)

    Troco K. Mihali

    2010-07-01

    Full Text Available Saxitoxin (STX and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs. PSTs are the causative agents of paralytic shellfish poisoning (PSP and are mostly associated with marine dinoflagellates (eukaryotes and freshwater cyanobacteria (prokaryotes, which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs—each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.

  15. Analog forecasting with dynamics-adapted kernels

    Science.gov (United States)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

    Analog forecasting is a nonparametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from kernel methods developed in harmonic analysis and machine learning and state-space reconstruction for dynamical systems. A key ingredient of our approach is to replace single-analog forecasting with weighted ensembles of analogs constructed using local similarity kernels. The kernels used here employ a number of dynamics-dependent features designed to improve forecast skill, including Takens’ delay-coordinate maps (to recover information in the initial data lost through partial observations) and a directional dependence on the dynamical vector field generating the data. Mathematically, our approach is closely related to kernel methods for out-of-sample extension of functions, and we discuss alternative strategies based on the Nyström method and the multiscale Laplacian pyramids technique. We illustrate these techniques in applications to forecasting in a low-order deterministic model for atmospheric dynamics with chaotic metastability, and interannual-scale forecasting in the North Pacific sector of a comprehensive climate model. We find that forecasts based on kernel-weighted ensembles have significantly higher skill than the conventional approach following a single analog.

  16. Analysis of Recurrent Analog Neural Networks

    Directory of Open Access Journals (Sweden)

    Z. Raida

    1998-06-01

    Full Text Available In this paper, an original rigorous analysis of recurrent analog neural networks, which are built from opamp neurons, is presented. The analysis, which comes from the approximate model of the operational amplifier, reveals causes of possible non-stable states and enables to determine convergence properties of the network. Results of the analysis are discussed in order to enable development of original robust and fast analog networks. In the analysis, the special attention is turned to the examination of the influence of real circuit elements and of the statistical parameters of processed signals to the parameters of the network.

  17. Implementing neural architectures using analog VLSI circuits

    Science.gov (United States)

    Maher, Mary Ann C.; Deweerth, Stephen P.; Mahowald, Misha A.; Mead, Carver A.

    1989-05-01

    Analog very large-scale integrated (VLSI) technology can be used not only to study and simulate biological systems, but also to emulate them in designing artificial sensory systems. A methodology for building these systems in CMOS VLSI technology has been developed using analog micropower circuit elements that can be hierarchically combined. Using this methodology, experimental VLSI chips of visual and motor subsystems have been designed and fabricated. These chips exhibit behavior similar to that of biological systems, and perform computations useful for artificial sensory systems.

  18. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  19. Formal analogies in physics teacher education

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio

    2012-01-01

    the relevance of the subject, formal analogies are rarely systematically approached in physics education. In order to discuss this issue with pre-service physics teachers, we planned a lecture and designed a questionnaire with the goal of encouraging them to think about some “coincidences” in well known......Reasoning by similarities, especially the ones associated with formal aspects, is one of the most valuable sources for the development of physical theories. The essential role of formal analogies in science can be highlighted by the fact that several equations for different physical situations have...... the exact same appearance. Coulomb’s law’s similarity with Newton’s, Maxwell’s application of fluid theory to electromagnetism and Hamilton’s optical mechanical analogy are some among many other examples. These cases illustrate the power of mathematics in providing unifying structures for physics. Despite...

  20. Analog Forecasting with Dynamics-Adapted Kernels

    CERN Document Server

    Zhao, Zhizhen

    2014-01-01

    Analog forecasting is a non-parametric technique introduced by Lorenz in 1969 which predicts the evolution of states of a dynamical system (or observables defined on the states) by following the evolution of the sample in a historical record of observations which most closely resembles the current initial data. Here, we introduce a suite of forecasting methods which improve traditional analog forecasting by combining ideas from state-space reconstruction for dynamical systems and kernel methods developed in harmonic analysis and machine learning. The first improvement is to augment the dimension of the initial data using Takens' delay-coordinate maps to recover information in the initial data lost through partial observations. Then, instead of using Euclidean distances between the states, weighted ensembles of analogs are constructed according to similarity kernels in delay-coordinate space, featuring an explicit dependence on the dynamical vector field generating the data. The eigenvalues and eigenfunctions ...

  1. Formal analogies in physics teacher education

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio

    2012-01-01

    the relevance of the subject, formal analogies are rarely systematically approached in physics education. In order to discuss this issue with pre-service physics teachers, we planned a lecture and designed a questionnaire with the goal of encouraging them to think about some “coincidences” in well known......Reasoning by similarities, especially the ones associated with formal aspects, is one of the most valuable sources for the development of physical theories. The essential role of formal analogies in science can be highlighted by the fact that several equations for different physical situations have...... the exact same appearance. Coulomb’s law’s similarity with Newton’s, Maxwell’s application of fluid theory to electromagnetism and Hamilton’s optical mechanical analogy are some among many other examples. These cases illustrate the power of mathematics in providing unifying structures for physics. Despite...

  2. Changes in analogical reasoning in adulthood.

    Science.gov (United States)

    Clark, E; Gardner, M K; Brown, G; Howell, R J

    1990-01-01

    This study sought to investigate adult intellectual development through an analysis of a particular type of cognitive ability, verbal analogical reasoning. The performance of 60 individuals between the ages of 20 and 79 was compared on 100 verbal analogies. The subjects consisted of six groups of ten individuals each (five males and five females), matched as a group for education and gender. Solution times and error rates served as the dependent measures. Results showed that there was a significant trend for the older subjects (60- and 70-year-olds) to be slower than the young subjects (20-, 30-, 40-, and 50-year-olds), but not necessarily more error prone. These data suggest that verbal analogical reasoning changes with age. Supplemental data demonstrated a change in other abilities as well (i.e., decline in perceptual-motor speed and spatial skill).

  3. Mathematical problem solving by analogy.

    Science.gov (United States)

    Novick, L R; Holyoak, K J

    1991-05-01

    We report the results of 2 experiments and a verbal protocol study examining the component processes of solving mathematical word problems by analogy. College students first studied a problem and its solution, which provided a potential source for analogical transfer. Then they attempted to solve several analogous problems. For some problems, subjects received one of a variety of hints designed to reduce or eliminate the difficulty of some of the major processes hypothesized to be involved in analogical transfer. Our studies yielded 4 major findings. First, the process of mapping the features of the source and target problems and the process of adapting the source solution procedure for use in solving the target problem were clearly distinguished: (a) Successful mapping was found to be insufficient for successful transfer and (b) adaptation was found to be a major source of transfer difficulty. Second, we obtained direct evidence that schema induction is a natural consequence of analogical transfer. The schema was found to co-exist with the problems from which it was induced, and both the schema and the individual problems facilitated later transfer. Third, for our multiple-solution problems, the relation between analogical transfer and solution accuracy was mediated by the degree of time pressure exerted for the test problems. Finally, mathematical expertise was a significant predictor of analogical transfer, but general analogical reasoning ability was not. The implications of the results for models of analogical transfer and for instruction were considered.

  4. 23rd workshop on Advances in Analog Circuit Design

    CERN Document Server

    Baschirotto, Andrea; Makinwa, Kofi

    2015-01-01

    This book is based on the 18 tutorials presented during the 23rd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, serving as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    • Includes coverage of high-performance analog-to-digital and digital to analog converters, integrated circuit design in scaled technologies, and time-domain signal processing; • Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; • Presents material in a tutorial-based format.

  5. The production of body analogs for use in radiation physics.

    Science.gov (United States)

    Metcalfe, P E; Hoban, P W; Harper, N R; Murray, D C; Round, W H

    1990-09-01

    Bone, muscle and lung analog materials have been produced in-house, and dosimetry phantoms have been produced. A method using computed tomography (CT) has been developed to check that the analogs produced match the radiation properties of body tissues. The relative electron densities and ratio of electron cross sections are calculated from elemental compositions of the analogs. Using these data the theoretical CT numbers are calculated and these numbers are compared with experimental CT numbers for the analogs produced. The experimental CT numbers are found by scanning the samples on a Siemens DRH CT scanner. Results show the maximum difference between theoretical and experimental CT numbers for the analogs is 18 Hounsfield units, which relates to a delta NCT of less than 1%. Comparison of analog CT numbers with CT numbers for the related patient tissues also shows a close match.

  6. 25th workshop on Advances in Analog Circuit Design

    CERN Document Server

    Harpe, Pieter; Makinwa, Kofi

    2017-01-01

    This book is based on the 18 tutorials presented during the 25th workshop on Advances in Analog Circuit Design. Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including low-power and energy-efficient analog electronics, with specific contributions focusing on the design of continuous-time sigma-delta modulators, automotive electronics, and power management. This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.

  7. Physical analogy between continuum thermodynamics and classical mechanics.

    Science.gov (United States)

    Umantsev, Alex

    2004-01-01

    The main focus of this paper is the profound physical analogy between a continuum thermodynamical system, which evolves with relaxation under (possibly) nonisothermal conditions, and a classical mechanical system of a few interacting particles moving with dissipation in (possibly), time-dependent nonconservative fields. This analogy is applied to the problem of phase transitions in a one-dimensional thermodynamic system. The thermomechanical analogy stems from the validity of variational methods in mechanics and thermodynamics and allows for a different interpretation of the dynamical selection principle in the theory of pattern formation. This physical analogy is very helpful for understanding different nonlinear thermodynamic phenomena and for developing intuition in numerical simulations.

  8. [Analogies and analogy research in technical biology and bionics].

    Science.gov (United States)

    Nachtigall, Werner

    2010-01-01

    The procedural approaches of Technical Biology and Bionics are characterized, and analogy research is identified as their common basis. The actual creative aspect in bionical research lies in recognizing and exploiting technically oriented analogies underlying a specific biological prototype to indicate a specific technical application.

  9. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  10. Conjecturing via Reconceived Classical Analogy

    Science.gov (United States)

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

    Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

  11. Musik som analogi og metafor

    DEFF Research Database (Denmark)

    2014-01-01

    Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

  12. Musik som analogi og metafor

    DEFF Research Database (Denmark)

    2014-01-01

    Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser......Indeholder underkapitlerne: 2.5.1 Musik som analogi 2.5.2 Musik som metafor 2.5.3 Musikkens psykologiske funktioner - en taxonomi og metaforisk lytning til fire baroksatser...

  13. Using Analogies to Prevent Misconceptions about Chemical Equilibrium

    Science.gov (United States)

    Sahin Pekmez, Esin

    2010-01-01

    The main purpose of this study was to find the effectiveness of using analogies to prevent misconceptions about chemical equilibrium. Nineteen analogies, which were based on dynamic aspects of chemical equilibrium and application of Le Chatelier's principle, were developed. The participations of this study consisted of 11th grade students (n: 151)…

  14. Using Gravitational Analogies to Introduce Elementary Electrical Field Theory Concepts

    Science.gov (United States)

    Saeli, Susan; MacIsaac, Dan

    2007-01-01

    Since electrical field concepts are usually unfamiliar, abstract, and difficult to visualize, conceptual analogies from familiar gravitational phenomena are valuable for teaching. Such analogies emphasize the underlying continuity of field concepts in physics and support the spiral development of student understanding. We find the following four…

  15. Analog modeling of transient moisture flow in unsaturated soil

    NARCIS (Netherlands)

    Wind, G.P.

    1979-01-01

    Hydraulic and electronic analog models are developed for the simulation of moisture flow and accumulation in unsaturated soil. The analog models are compared with numerical models and checked with field observations. Application of soil physical knowledge on a soil technological problem by means of

  16. Neotectonic development of the El Salvador Fault Zone and implications for deformation in the Central America Volcanic Arc: Insights from 4-D analog modeling experiments

    Science.gov (United States)

    Alonso-Henar, Jorge; Schreurs, Guido; Martinez-Díaz, José Jesús; Álvarez-Gómez, José Antonio; Villamor, Pilar

    2015-01-01

    The El Salvador Fault Zone (ESFZ) is an active, approximately 150 km long and 20 km wide, segmented, dextral strike-slip fault zone within the Central American Volcanic Arc striking N100°E. Although several studies have investigated the surface expression of the ESFZ, little is known about its structure at depth and its kinematic evolution. Structural field data and mapping suggest a phase of extension, at some stage during the evolution of the ESFZ. This phase would explain dip-slip movements on structures that are currently associated with the active, dominantly strike slip and that do not fit with the current tectonic regime. Field observations suggest trenchward migration of the arc. Such an extension and trenchward migration of the volcanic arc could be related to slab rollback of the Cocos plate beneath the Chortis Block during the Miocene/Pliocene. We carried out 4-D analog model experiments to test whether an early phase of extension is required to form the present-day fault pattern in the ESFZ. Our experiments suggest that a two-phase tectonic evolution best explains the ESFZ: an early pure extensional phase linked to a segmented volcanic arc is necessary to form the main structures. This extensional phase is followed by a strike-slip dominated regime, which results in intersegment areas with local transtension and segments with almost pure strike-slip motion. The results of our experiments combined with field data along the Central American Volcanic Arc indicate that the slab rollback intensity beneath the Chortis Block is greater in Nicaragua and decreases westward to Guatemala.

  17. How to use analogies for breakthrough innovations

    OpenAIRE

    Schild, Katharina; Herstatt, Cornelius; Lüthje, Christian

    2004-01-01

    Analogies can trigger breakthrough ideas in new product development. Numerous examples demonstrate that substantial innovations often result from transferring problem solutions from one industry or domain to another. For instance, the designers of the new running shoe generation of Nike, “Nike SHOX”, use the same suspension concept like the technologies applied for Formula 1 racing cars, or the biological Lotus-effect led to the development of various self-cleaning surfaces. Academic resea...

  18. Nonpeptide somatostatin analogs: recent advances in its application and research

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Along with its wide anatomical distribution, somatostatin (SST) acts on multiple targets via a family of 5 receptors to produce a broad spectrum of biological effects. Therefore, a variety of peptide analogs have been produced and are widely used in clinical treatment. However, because of their flaws in the structure of peptide, the clinical efficacy is limited. In this review, we summarize the structure, pharmacological effects and the potential clinical value of non-peptide SST analogs. We focus on the research and development of non-peptide SST analogs since 1998, and discuss the problems and potential prospects for non-peptide SST analogs. We believe that as more non-peptide somatostatin analogs are successfully developed, the extensive clinical application of SSTs will contribute a great deal to medical science.

  19. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  20. Distributed Episodic and Analogical Reasoning (DEAR)

    Science.gov (United States)

    2010-04-01

    ends analysis Carbonell 1983 Modeling of Analogy Making Structure Mapping Theory (SMT) Gentner 1984 Agent based approach to analogy making...Mapping Engine (SME) Forbus 1990 Learning by analogy with larger domains Prodigy/Analogy Veloso and Carbonell 1991 Analogical Retrieval Engine MAC/FAC

  1. Molecular modeling of fentanyl analogs

    Directory of Open Access Journals (Sweden)

    LJILJANA DOSEN-MICOVIC

    2004-11-01

    Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

  2. Sulfonimidamide analogs of oncolytic sulfonylureas.

    Science.gov (United States)

    Toth, J E; Grindey, G B; Ehlhardt, W J; Ray, J E; Boder, G B; Bewley, J R; Klingerman, K K; Gates, S B; Rinzel, S M; Schultz, R M; Weir, L C; Worzalla, J F

    1997-03-14

    A series of sulfonimidamide analogs of the oncolytic diarylsulfonylureas was synthesized and evaluated for (1) in vitro cytotoxicity against CEM cells, (2) in vivo antitumor activity against subaxillary implanted 6C3HED lymphosarcoma, and (3) metabolic breakdown to the o-sulfate of p-chloroaniline. The separated enantiomers of one sulfonimidamide analog displayed very different activities in the in vivo screening model. In general, several analogs demonstrated excellent growth inhibitory activity in the 6C3HED model when dosed orally or intraperitoneally. A correlative structure-activity relationship to the oncolytic sulfonylureas was not apparent.

  3. Factors Affecting the Difficulty of Verbal Analogies.

    Science.gov (United States)

    Roccas, Sonia; Moshinsky, Avital

    2003-01-01

    Examined factors affecting the difficulty of verbal analogies in a psychometric examination by characterizing 104 analogies using 5 defined attributes. Both knowledge and process attributes were found to contribute to the difficulty of verbal analogies assessed by 10 judges. (SLD)

  4. Solving a problem by analogy

    Science.gov (United States)

    Easton, Don

    1999-03-01

    This note is a description of a student solution to a problem. I found the solution exciting because it exemplifies the kind of solution by analogy that Feynman describes in The Feynman Lectures on Physics.

  5. Analog CMOS contrastive Hebbian networks

    Science.gov (United States)

    Schneider, Christian; Card, Howard

    1992-09-01

    CMOS VLSI circuits implementing an analog neural network with on-chip contrastive Hebbian learning and capacitive synaptic weight storage have been designed and fabricated. Weights are refreshed by periodic repetition of the training data. To evaluate circuit performance in a medium-sized system, these circuits were used to build a 132 synapse neural network. An adaptive neural system, such as the one described in this paper, can compensate for imperfections in the components from which it is constructed, and thus it is possible to build this type of system using simple, silicon area-efficient analog circuits. Because these analog VLSI circuits are far more compact than their digital counterparts, analog VLSI neural network implementations are potentially more efficient than digital ones.

  6. Verbal Analogies in the ITPA

    Science.gov (United States)

    Levinson, Philip J.; Kunze, Luvern H.

    1973-01-01

    This study examined the extent to which the Auditory Association subtest of the revised Illinois Test of Psycholinguistic Abilities (ITPA) measures the ability of children to complete verbal analogies. (Author)

  7. A New Approach for Modeling Darrieus-Type Vertical Axis Wind Turbine Rotors Using Electrical Equivalent Circuit Analogy: Basis of Theoretical Formulations and Model Development

    National Research Council Canada - National Science Library

    Pierre Tchakoua; Rene Wamkeue; Mohand Ouhrouche; Tommy Andy Tameghe; Gabriel Ekemb

    2015-01-01

    .... Thus, models can significantly reduce design, development and optimization costs. This paper proposes a novel equivalent electrical model for Darrieus-type vertical axis wind turbines (DTVAWTs...

  8. Analog electronic neural network circuits

    Energy Technology Data Exchange (ETDEWEB)

    Graf, H.P.; Jackel, L.D. (AT and T Bell Labs., Holmdel, NJ (USA))

    1989-07-01

    The large interconnectivity and moderate precision required in neural network models present new opportunities for analog computing. This paper discusses analog circuits for a variety of problems such as pattern matching, optimization, and learning. Most of the circuits build so far are relatively small, exploratory designs. The most mature circuits are those for template matching. Chips performing this function are now being applied to pattern recognition problems.

  9. Novel Analog For Muscle Deconditioning

    Science.gov (United States)

    Ploutz-Snyder, Lori; Ryder, Jeff; Buxton, Roxanne; Redd. Elizabeth; Scott-Pandorf, Melissa; Hackney, Kyle; Fiedler, James; Ploutz-Snyder, Robert; Bloomberg, Jacob

    2011-01-01

    Existing models (such as bed rest) of muscle deconditioning are cumbersome and expensive. We propose a new model utilizing a weighted suit to manipulate strength, power, or endurance (function) relative to body weight (BW). Methods: 20 subjects performed 7 occupational astronaut tasks while wearing a suit weighted with 0-120% of BW. Models of the full relationship between muscle function/BW and task completion time were developed using fractional polynomial regression and verified by the addition of pre-and postflightastronaut performance data for the same tasks. Splineregression was used to identify muscle function thresholds below which task performance was impaired. Results: Thresholds of performance decline were identified for each task. Seated egress & walk (most difficult task) showed thresholds of leg press (LP) isometric peak force/BW of 18 N/kg, LP power/BW of 18 W/kg, LP work/BW of 79 J/kg, isokineticknee extension (KE)/BW of 6 Nm/kg, and KE torque/BW of 1.9 Nm/kg.Conclusions: Laboratory manipulation of relative strength has promise as an appropriate analog for spaceflight-induced loss of muscle function, for predicting occupational task performance and establishing operationally relevant strength thresholds.

  10. Uncertainty Relations for Analog Signals

    CERN Document Server

    Eldar, Yonina C

    2008-01-01

    In the past several years there has been a surge of research investigating various aspects of sparse representations and compressed sensing. Most of this work has focused on the finite-dimensional setting in which the goal is to decompose a finite-length vector into a given finite dictionary. Underlying many of these results is the conceptual notion of an uncertainty principle: a signal cannot be sparsely represented in two different bases. Here, we extend these ideas and results to the analog, infinite-dimensional setting by considering signals that lie in a finitely-generated shift-invariant (SI) space. This class of signals is rich enough to include many interesting special cases such as multiband signals and splines. By adapting the notion of coherence defined for finite dictionaries to infinite SI representations, we develop an uncertainty principle similar in spirit to its finite counterpart. We demonstrate tightness of our bound by considering a bandlimited low-pass comb that achieves the uncertainty p...

  11. HOW TO USE ANALOGIES FOR BREAKTHROUGH INNOVATIONS

    OpenAIRE

    CORNELIUS HERSTATT; KATHARINA KALOGERAKIS

    2005-01-01

    Analogies can trigger breakthrough ideas in new product development. Numerous examples demonstrate that substantial innovations often result from transferring problem solutions from one industry or domain to another. For instance, the designers of the new running show generation of Nike, "Nike SHOX", use the same suspension concept like the technologies applied for formula 1 racing cars, or the biological Lotus-effect leading to the evelopment of various self-cleaning surfaces. Academic resea...

  12. Analog of landau Levels to Electric Dipole

    CERN Document Server

    Ribeiro, L R; Nascimento, J R; Furtado, Claudio

    2006-01-01

    In this article we discuss the analogy between the dynamics of a neutral particle with an electric dipole, in the presence of configuration of magnetic field, with Landau level quantization for charged particle. We analyze this quantization based on the He-Mckelar-Wilkens interaction developed of similar way that Ericsson and Sj\\"oqvist[Phys Rev. A {\\bf 65} 013607 (2001)] was analyzed the Landau-Aharonov-Casher effect. The energy level and eingenfuctions and eigenvalues are obtained.

  13. Learning Plate Tectonics Using a Pre-Analogy Step

    Science.gov (United States)

    Glesener, G. B.; Sandoval, W. A.

    2011-12-01

    Previous research has shown that children tend to demonstrate lower performance on analogical reasoning tasks at a causal relations level compared to most adults (Gentner & Toupin, 1986). This tendency is an obstacle that geoscience educators must overcome because of the high frequency of analogies used in geoscience pedagogy. In particular, analog models are used to convey complex systems of non-everyday/non-observable events found in nature, such as plate tectonics. Key factors in successful analogical reasoning that have been suggested by researchers include knowledge of the causal relations in the base analog (Brown & Kane, 1988; Gentner, 1988; Gentner & Toupin, 1986), and development of learning strategies and metaconceptual competence(Brown & Kane, 1988). External factors, such as guiding cues and hints have been useful cognitive supports that help students reason through analogical problems (Gick & Holyoak, 1980). Cognitive supports have been seen by researchers to decrease processing demands on retrieval and working memory (Richland, Zur, & Holyoak, 2007). We observed third and fourth graders learning about plate tectonics beginning with a pre-analogy step-a cognitive support activity a student can do before working with an analogy to understand the target. This activity was designed to aid students in developing their understanding of object attributes and relations within an analog model so that more focus can be placed on mapping the corresponding higher-order relations between the base and target. Students learned targeted concepts of plate tectonics, as measured by pre to post gains on items adapted from the Geosciences Concept Inventory. Analyses of classroom interaction showed that students used the object attributes and higher-order relations highlighted in the pre-analogy activity as resources to reason about plate boundaries and plate movement during earthquakes.

  14. Multilateral Research Opportunities in Ground Analogs

    Science.gov (United States)

    Corbin, Barbara J.

    2015-01-01

    The global economy forces many nations to consider their national investments and make difficult decisions regarding their investment in future exploration. International collaboration provides an opportunity to leverage other nations' investments to meet common goals. The Humans In Space Community shares a common goal to enable safe, reliable, and productive human space exploration within and beyond Low Earth Orbit. Meeting this goal requires efficient use of limited resources and International capabilities. The International Space Station (ISS) is our primary platform to conduct microgravity research targeted at reducing human health and performance risks for exploration missions. Access to ISS resources, however, is becoming more and more constrained and will only be available through 2020 or 2024. NASA's Human Research Program (HRP) is actively pursuing methods to effectively utilize the ISS and appropriate ground analogs to understand and mitigate human health and performance risks prior to embarking on human exploration of deep space destinations. HRP developed a plan to use ground analogs of increasing fidelity to address questions related to exploration missions and is inviting International participation in these planned campaigns. Using established working groups and multilateral panels, the HRP is working with multiple Space Agencies to invite International participation in a series of 30- day missions that HRP will conduct in the US owned and operated Human Exploration Research Analog (HERA) during 2016. In addition, the HRP is negotiating access to Antarctic stations (both US and non-US), the German :envihab and Russian NEK facilities. These facilities provide unique capabilities to address critical research questions requiring longer duration simulation or isolation. We are negotiating release of international research opportunities to ensure a multilateral approach to future analog research campaigns, hoping to begin multilateral campaigns in the

  15. Analog approach to mixed analog-digital circuit simulation

    Science.gov (United States)

    Ogrodzki, Jan

    2013-10-01

    Logic simulation of digital circuits is a well explored research area. Most up-to-date CAD tools for digital circuits simulation use an event driven, selective trace algorithm and Hardware Description Languages (HDL), e.g. the VHDL. This techniques enable simulation of mixed circuits, as well, where an analog part is connected to the digital one through D/A and A/D converters. The event-driven mixed simulation applies a unified, digital-circuits dedicated method to both digital and analog subsystems. In recent years HDL techniques have been also applied to mixed domains, as e.g. in the VHDL-AMS. This paper presents an approach dual to the event-driven one, where an analog part together with a digital one and with converters is treated as the analog subsystem and is simulated by means of circuit simulation techniques. In our problem an analog solver used yields some numerical problems caused by nonlinearities of digital elements. Efficient methods for overriding these difficulties have been proposed.

  16. Progress on development situation, mechanism and biosynthesis of rapamycin and its analogs%雷帕霉素及其衍生物开发现状、作用机制及生物合成研究进展

    Institute of Scientific and Technical Information of China (English)

    李进; 邹祥

    2011-01-01

    目的 介绍了近年来雷帕霉素及其衍生物的开发现状、作用机制与生物合成途径,探讨了通过前体定向生物合成与诱变生物合成的方式,获得雷帕霉素衍生物的研究进展,展望了雷帕霉素及衍生物的研究前景.方法 分析、归纳、总结近年来发表的相关文献.结果与结论 雷帕霉素及其衍生物是新型强效的免疫抑制剂与抗肿瘤药物,具有抗真菌、抗增殖及潜在延长哺乳动物寿命周期等作用.采用前体定向生物合成、诱变生物合成与组合生物合成的方式,可快速获得其具药理活性的衍生物.基于生物合成途径,采用系统生物学相关手段可获高产工程化菌种应用于工业化生产.%Objective The recent development situation, mechanism and biosynthesis of rapamycin and its derivatives were reviewed, and the research prospect of rapamycin and its analogs were further forecasted. Methods The literatures published in recent years were analyzed and summarized. Results and Conclusion Rapamycin and some its analogs are new potent immunosuppressive and anticancer drugs, which have obvious effects on anti-fungal, anti-proliferation, and the potential to extend the lifespan of mammalian and so on. By the ways of precursor-directed biosynthesis,mutational biosynthesis and combinatorial biosynthesis, some novel analogs of rapamycin can be obtained,and the high-yield strains tend to be reconstructed for industrial production by the means of system biology.

  17. Analog readout modules for the ZEUS microvertex detector

    CERN Document Server

    Fusayasu, T

    1999-01-01

    Analog readout modules have been developed for a silicon microvertex detector of the electron-proton collision experiment ZEUS. Analog signals kept in the front end are read out and digitized by ADCs and processed afterwards to reduce the data volume while keeping the signal information. We have developed prototype modules with 10-bit 10 MHz ADCs and digital processors built in Field Programmable Gate Arrays. Their performance was investigated.

  18. Polyunsaturated fatty acid analogs act antiarrhythmically on the cardiac IKs channel

    DEFF Research Database (Denmark)

    Liin, Sara I.; Silverå Ejneby, Malin; Barro-Soria, Rene;

    2015-01-01

    charge at neutral pH, restore the sensitivity to open IKs channels. PUFA analogs with a positively charged head group inhibit IKs channels. These different PUFA analogs could be developed into drugs to treat cardiac arrhythmias. In support of this possibility, we show that PUFA analogs act...

  19. Activity of pentamidine and pentamidine analogs against Toxoplasma gondii in cell cultures.

    OpenAIRE

    Lindsay, D S; Blagburn, B L; Hall, J. E.; Tidwell, R R

    1991-01-01

    The capabilities of pentamidine and nine pentamidine analogs to inhibit the development of Toxoplasma gondii were examined in vitro. Treatment of infected cultures with pentamidine and five of its analogs caused a significant (P less than 0.05) reduction in the numbers of tachyzoites produced. Analogs of pentamidine may be useful agents in the treatment of toxoplasmosis.

  20. IIP framework: A tool for reuse-centric analog circuit design

    OpenAIRE

    2016-01-01

    Current design of analog integrated circuits is still a time-consuming manual process resulting in static analog blocks which can hardly be reused. In order to address this problem, a new framework to ease reuse-centric bottom-up design of analog integrated circuits is introduced. Our IIP Framework (IIP: Intelligent Intellectual Property) enables the development of highly technology-independent analog circuit generators applicable in multiple design environments. IIP Generators are parameteri...

  1. Insulin Analogs: Impact on Treatment Success, Satisfaction, Quality of Life, and Adherence

    OpenAIRE

    Hartman, Israel

    2008-01-01

    A growing body of medical research has demonstrated that intensive control of serum glucose levels can minimize the development of diabetes-related complications. Success with insulin management ultimately depends on how closely a given regimen can mimic normal physiologic insulin release patterns. The new insulin analogs, including the rapid-acting analogs (aspart, lispro, glulisine), the long-acting basal analogs (glargine, detemir), and the premixed insulin analog formulations (75% neutral...

  2. A new program on digitizing analog seismograms

    Science.gov (United States)

    Wang, Maofa; Jiang, Qigang; Liu, Qingjie; Huang, Meng

    2016-08-01

    Historical seismograms contain a great variety of useful information which can be used in the study of earthquakes. It is necessary for researchers to digitize analog records and extract the information just as modern computing analysis requires. Firstly, an algorithm based on color scene filed method is presented in order to digitize analog seismograms. Secondly, an interactive software program using C# has been developed to digitize seismogram traces from raster files quickly and accurately. The program can deal with gray-scale images stored in a suitable file format and it offers two different methods: manual digitization and automatic digitization. The test result of the program shows that the methods presented in this paper can lead to good performance.

  3. Analog Computation by DNA Strand Displacement Circuits.

    Science.gov (United States)

    Song, Tianqi; Garg, Sudhanshu; Mokhtar, Reem; Bui, Hieu; Reif, John

    2016-08-19

    DNA circuits have been widely used to develop biological computing devices because of their high programmability and versatility. Here, we propose an architecture for the systematic construction of DNA circuits for analog computation based on DNA strand displacement. The elementary gates in our architecture include addition, subtraction, and multiplication gates. The input and output of these gates are analog, which means that they are directly represented by the concentrations of the input and output DNA strands, respectively, without requiring a threshold for converting to Boolean signals. We provide detailed domain designs and kinetic simulations of the gates to demonstrate their expected performance. On the basis of these gates, we describe how DNA circuits to compute polynomial functions of inputs can be built. Using Taylor Series and Newton Iteration methods, functions beyond the scope of polynomials can also be computed by DNA circuits built upon our architecture.

  4. Targeting thyroid diseases with TSH receptor analogs.

    Science.gov (United States)

    Galofré, Juan C; Chacón, Ana M; Latif, Rauf

    2013-12-01

    The thyroid-stimulating hormone (TSH) receptor (TSHR) is a major regulator of thyroid function and growth, and is the key antigen in several pathological conditions including hyperthyroidism, hypothyroidism, and thyroid tumors. Various effective treatment strategies are currently available for many of these clinical conditions such as antithyroid drugs or radioiodine therapy, but they are not devoid of side effects. In addition, treatment of complications of Graves' disease such as Graves' ophthalmopathy is often difficult and unsatisfactory using current methods. Recent advances in basic research on both in vitro and in vivo models have suggested that TSH analogs could be used for diagnosis and treatment of some of the thyroid diseases. The advent of high-throughput screening methods has resulted in a group of TSH analogs called small molecules, which have the potential to be developed as promising drugs. Small molecules are low molecular weight compounds with agonist, antagonist and, in some cases, inverse agonist activity on TSHR. This short review will focus on current advances in development of TSH analogs and their potential clinical applications. Rapid advances in this field may lead to the conduct of clinical trials of small molecules related to TSHR for the management of Graves' disease, thyroid cancer, and thyroid-related osteoporosis in the coming years. Copyright © 2012 SEEN. Published by Elsevier Espana. All rights reserved.

  5. Insights into contaminant transport from unconventional oil and gas developments from analog system analysis of methane-bearing thermal springs in the northern Canadian Rocky Mountains

    Science.gov (United States)

    Ferguson, Grant; Grasby, Stephen E.

    2017-09-01

    Natural gas is currently being produced from shales of the Montney and Liard basins in western Canada. Production requires hydraulic fracturing due to the low permeability of the shales in the basins. Stratigraphically equivalent shales are present in the northern Canadian Rocky Mountains. Thermal springs with notable hydrocarbon concentrations occur where large-scale faults intersect the same shale units that are the focus of gas development, indicating that under certain circumstances, connection of deep fractured shales to the land surface is possible. To constrain these conditions, simulations were conducted for the spring with the highest hydrocarbon flux (Toad River Spring), results of which indicate that in order to supply sufficient water to a fault to support measurable advection, the effective permeability of the shales in these structurally deformed areas must be one to four orders of magnitude higher than in areas of active gas production to the east. The spatial scale of enhanced permeability is much greater than that which is achieved by hydraulic fracturing and the mechanism of maintaining high pressures at depth is more persistent in time. Examination of groundwater velocities suggests that upward migration of solutes from hydraulic fracturing may take decades to centuries. Results also indicate that any temperature anomaly will be associated with transport along a fault at such velocities. No such temperature anomaly has been documented in regions with unconventional oil and gas development to date. Such an anomaly would be diagnostic of a deep solute source.

  6. Analog-Digital Interfaces

    Science.gov (United States)

    Keller, Matthias; Murmann, Boris; Manoli, Yiannos

    This chapter discusses trends in the area of low-power, high-performance A/D conversion. Survey data collected over the past thirteen years are examined to show that the conversion energy of ADCs has halved every two years while the speed-resolution product has doubled approximately only every four years. A closer inspection on the impact of technology scaling and developments in ADC design are then presented to explain the observed trends. Next, opportunities in minimalistic and digitally assisted design are reviewed for the most popular converter architectures. Finally, trends in Delta-Sigma ADCs are analyzed in detail.

  7. Development of high-specific-activity (68)Ga-labeled DOTA-rhenium-cyclized alpha-MSH peptide analog to target MC1 receptors overexpressed by melanoma tumors.

    Science.gov (United States)

    Cantorias, Melchor V; Figueroa, Said D; Quinn, Thomas P; Lever, John R; Hoffman, Timothy J; Watkinson, Lisa D; Carmack, Terry L; Cutler, Cathy S

    2009-07-01

    A previous report on (68)Ga-1,4,7,10-tetraazacyclodedecane-N,N',N'',N'''-tetraacetic acid (DOTA)-Re(Arg(11))CCMSH was shown to indicate the imaging agent's potency for early detection of metastatic melanoma. However, the main limiting factor to developing high-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH is the short half-life of (68)Ga, which precludes further purification of the agent. To circumvent this problem, we incorporated the microwave technique to rapidly radiolabel the peptide with (68)Ga, thereby allowing enough time to include high-performance liquid chromatography (HPLC) purification in the overall procedure. DOTA-Re(Arg(11))CCMSH was radiolabeled with (68)Ga in 68)Ga-DOTA-Re(Arg(11))CCMSH was then administered on B16/F1 murine melanoma-bearing C57 mice to study its biodistribution and positron emission tomography (PET) imaging capability. The production of high-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH resulted in an improved tumor uptake [6.93+/-1.11%ID/g at 30 min postinjection (p.i.) and 6.27+/-1.60%ID/g at 1 h p.i.] and tumor retention (5.85+/-1.32%ID/g at 4 h p.i.). Receptor-mediated tumor uptake was verified by blocking studies. Furthermore, high-resolution PET images of the tumor were obtained, owing to high tumor-to-nontarget organ ratios at an early time point (i.e., at 1 h biodistribution: tumor/blood, 14.3; tumor/muscle, 89.6; tumor/skin, 12.3) and fast clearance of the labeled peptide from kidney and other healthy tissues. High-specific-activity (68)Ga-DOTA-Re(Arg(11))CCMSH may have a potential role in the early diagnosis of metastasized melanoma.

  8. Current-mode analog nonlinear function synthesizer structures

    CERN Document Server

    Popa, Cosmin Radu

    2013-01-01

    This book is dedicated to the analysis and design of analog CMOS nonlinear function synthesizer structures, based on original superior-order approximation functions. A variety of analog function synthesizer structures are discussed, based on accurate approximation functions.  Readers will be enabled to implement numerous circuit functions with applications in analog signal processing, including exponential, Gaussian or hyperbolic functions. Generalizing the methods for obtaining these particular functions, the author analyzes superior-order approximation functions, which represent the core for developing CMOS analog nonlinear function synthesizers.   ·         Describes novel methods for generating a multitude of circuit functions, based on superior-order improved accuracy approximation functions; ·         Presents techniques for analog function synthesizers that can be applied easily to a wide variety of analog signal processing circuits; ·         Enables the design of analog s...

  9. 49205 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1997-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course 49205 Analog and Digital Filters...

  10. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  11. Mathematical Analogy and Metaphorical Insight

    Science.gov (United States)

    Zwicky, Jan

    2010-01-01

    How are we to understand the power of certain literary metaphors? The author argues that the apprehension of good metaphors is importantly similar to the apprehension of fruitful mathematical analogies: both involve a structural realignment of vision. The author then explores consequences of this claim, drawing conceptually significant parallels…

  12. Schema Training in Analogical Reasoning.

    Science.gov (United States)

    Robins, Shani; Mayer, Richard E.

    1993-01-01

    In 3 experiments, 93, 97, and 86 college students, respectively, learned how to solve 20 verbal analogy problems and took transfer and memory tests. Results are inconsistent with active responding theory and further indicate that schema induction is maximized when the schemas are made salient and the cognitive system is not overloaded. (SLD)

  13. 49205 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1997-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course 49205 Analog and Digital Filters...

  14. Understanding & Teaching Genetics Using Analogies

    Science.gov (United States)

    Woody, Scott; Himelblau, Ed

    2013-01-01

    We present a collection of analogies that are intended to help students better understand the foreign and often nuanced vocabulary of the genetics curriculum. Why is it called the "wild type"? What is the difference between a locus, a gene, and an allele? What is the functional (versus a rule-based) distinction between dominant and…

  15. Processes in Verbal Analogy Solution.

    Science.gov (United States)

    Grudin, Jonathan

    1980-01-01

    Verbal analogy solution is more flexible than is suggested by either the standard process theory or Sternberg's theory. It was determined that subjects initially examine terms A and B; if this strategy is not successful, they examine the relationship between A and C. (Author/CP)

  16. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Differential effects of prenatal chronic high-decibel noise and music exposure on the excitatory and inhibitory synaptic components of the auditory cortex analog in developing chicks (Gallus gallus domesticus).

    Science.gov (United States)

    Kumar, V; Nag, T C; Sharma, U; Jagannathan, N R; Wadhwa, S

    2014-06-06

    Proper development of the auditory cortex depends on early acoustic experience that modulates the balance between excitatory and inhibitory (E/I) circuits. In the present social and occupational environment exposure to chronic loud sound in the form of occupational or recreational noise, is becoming inevitable. This could especially disrupt the functional auditory cortex development leading to altered processing of complex sound and hearing impairment. Here we report the effects of prenatal chronic loud sound (110-dB sound pressure level (SPL)) exposure (rhythmic [music] and arrhythmic [noise] forms) on the molecular components involved in regulation of the E/I balance in the developing auditory cortex analog/Field L (AuL) in domestic chicks. Noise exposure at 110-dB SPL significantly enhanced the E/I ratio (increased expression of AMPA receptor GluR2 subunit and glutamate with decreased expression of GABA(A) receptor gamma 2 subunit and GABA), whereas loud music exposure maintained the E/I ratio. Expressions of markers of synaptogenesis, synaptic stability and plasticity i.e., synaptophysin, PSD-95 and gephyrin were reduced with noise but increased with music exposure. Thus our results showed differential effects of prenatal chronic loud noise and music exposures on the E/I balance and synaptic function and stability in the developing auditory cortex. Loud music exposure showed an overall enrichment effect whereas loud noise-induced significant alterations in E/I balance could later impact the auditory function and associated cognitive behavior. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  18. Development of Anthropometric Analogous Headforms. Phase 1.

    Science.gov (United States)

    1994-10-31

    to treat the key dimensions as random variables. Recall the definition of a continuous random variable X over the sample space 0• x < 1: the... recall that for joint distributions of several random variables, single integrals become multiple integrals of corresponding dimensions. To fix...Warrendale, Pa. 1606 p. 1985-1991. Pp. 4.34.218-4.34.223. 1993. Guidelines for Evaluating Child Restraint System Interactions with Deploying Airbags

  19. A Novel cooked extruded lentils analog: physical and chemical properties.

    Science.gov (United States)

    Abu-Ghoush, Mahmoud; Alavi, Sajid; Al-Shathri, Abdulaziz

    2015-07-01

    Developing an extruded lentil analog is our aim. Lentil analog with six formulations were produced using a pilot-scale single (SS) and twin screw (TS) extruders. Texture analysis of lentil analogs prepared for consumption revealed that the products formulated with 60:40 and 70:30 soy: wheat ratios exhibited a significantly higher hardness, adhesiveness and lower springiness as compared to all other treatments. Differential Scanning Calorimeter (DSC) results indicated that all starches in dry blend are completely 100 % gelatinized by extrusion for all treatments at 100 °C. The maximum peak of viscosity for TS was formed after 5.58 min. from the run at 89.9 °C for the best treatment. However, this lentil analog product can provide a high quality lentil which can be used as a substitute for regular lentils.

  20. Digitoxin and its analogs as novel cancer therapeutics

    Directory of Open Access Journals (Sweden)

    Elbaz Hosam A

    2012-04-01

    Full Text Available Abstract A growing body of evidence indicates that digitoxin cardiac glycoside is a promising anticancer agent when used at therapeutic concentrations. Digitoxin has a prolonged half-life and a well-established clinical profile. New scientific avenues have shown that manipulating the chemical structure of the saccharide moiety of digitoxin leads to synthetic analogs with increased cytotoxic activity. However, the anticancer mechanism of digitoxin or synthetic analogs is still subject to study while concerns about digitoxin's cardiotoxicity preclude its clinical application in cancer therapeutics. This review focuses on digitoxin and its analogs, and their cytotoxicity against cancer cells. Moreover, a new perspective on the pharmacological aspects of digitoxin and its analogs is provided to emphasize new research directions for developing potent chemotherapeutic drugs.

  1. 22nd Workshop on Advances in Analog Circuit Design

    CERN Document Server

    Makinwa, Kofi; Harpe, Pieter

    2014-01-01

    This book is based on the 18 tutorials presented during the 22nd workshop on Advances in Analog Circuit Design.  Expert designers present readers with information about a variety of topics at the frontier of analog circuit design, including frequency reference, power management for systems-on-chip, and smart wireless interfaces.  This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.    ·         Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; ·         Presents material in a tutorial-based format; ·         Includes coverage of frequency reference, power management for systems-on-chip, and smart wireless interfaces.

  2. Analog circuit design art, science and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    This book is far more than just another tutorial or reference guide - it's a tour through the world of analog design, combining theory and applications with the philosophies behind the design process. Readers will learn how leading analog circuit designers approach problems and how they think about solutions to those problems. They'll also learn about the `analog way' - a broad, flexible method of thinking about analog design tasks.A comprehensive and useful guide to analog theory and applications. Covers visualizing the operation of analog circuits. Looks at how to rap

  3. Analog-digital converters for industrial applications including an introduction to digital-analog converters

    CERN Document Server

    Ohnhäuser, Frank

    2015-01-01

    This book offers students and those new to the topic of analog-to-digital converters (ADCs) a broad introduction, before going into details of the state-of-the-art design techniques for SAR and DS converters, including the latest research topics, which are valuable for IC design engineers as well as users of ADCs in applications. The book then addresses important topics, such as correct connectivity of ADCs in an application, the verification, characterization and testing of ADCs that ensure high-quality end products. Analog-to-digital converters are the central element in any data processing system and regulation loops such as modems or electrical motor drives. They significantly affect the performance and resolution of a system or end product. System development engineers need to be familiar with the performance parameters of the converters and understand the advantages and disadvantages of the various architectures. Integrated circuit development engineers have to overcome the problem of achieving high per...

  4. Novel Gemini vitamin D3 analogs

    DEFF Research Database (Denmark)

    Okamoto, Ryoko; Gery, Sigal; Kuwayama, Yoshio

    2014-01-01

    anticancer potency, but similar toxicity causing hypercalcemia. We focused on the effect of these compounds on the stimulation of expression of human cathelicidin antimicrobial peptide (CAMP) whose gene has a vitamin D response element in its promoter. Expression of CAMP mRNA and protein increased in a dose......-response fashion after exposure of acute myeloid leukemia (AML) cells to the Gemini analog, BXL-01-126, in vitro. A xenograft model of AML was developed using U937 AML cells injected into NSG-immunodeficient mice. Administration of vitamin D3 compounds to these mice resulted in substantial levels of CAMP...

  5. Microstore: the Stanford analog memory unit

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.T.; Chae, S.I.; Shapiro, S.; Larsen, R.S.

    1984-11-01

    An NMOS device has been developed which provides high speed analog signal storage and readout for time expansion of transient signals. This device takes advantage of HMOS-1 VLSI technology to implement an array of 256 storage cells. Sequential samples of an input waveform can be taken every 5 ns while providing an effective sampling aperture time of less than 1 ns. The design signal-to-noise ratio is 1 part in 2000. Digital control circuitry is provided on the chip for controlling the read-in and read-out processes. A reference circuit is incorporated in the chip for first order compensation of leakage drifts, sampling pedestals, and temperature effects.

  6. Synaptic dynamics in analog VLSI.

    Science.gov (United States)

    Bartolozzi, Chiara; Indiveri, Giacomo

    2007-10-01

    Synapses are crucial elements for computation and information transfer in both real and artificial neural systems. Recent experimental findings and theoretical models of pulse-based neural networks suggest that synaptic dynamics can play a crucial role for learning neural codes and encoding spatiotemporal spike patterns. Within the context of hardware implementations of pulse-based neural networks, several analog VLSI circuits modeling synaptic functionality have been proposed. We present an overview of previously proposed circuits and describe a novel analog VLSI synaptic circuit suitable for integration in large VLSI spike-based neural systems. The circuit proposed is based on a computational model that fits the real postsynaptic currents with exponentials. We present experimental data showing how the circuit exhibits realistic dynamics and show how it can be connected to additional modules for implementing a wide range of synaptic properties.

  7. Holism and nonseparability by analogy

    Science.gov (United States)

    Arageorgis, Aristidis

    2013-08-01

    This paper explores the issues of holism and nonseparability in relativistic quantum field theory (QFT) by focusing on an analog of the typical model featuring in many discussions of holism and nonseparability in nonrelativistic quantum mechanics. It is argued that the quantum field theoretic model does exhibit holism in a metaphysical sense and that there are plausible grounds to view QFT holistic in an epistemological sense. However, the complexities arising from the fact that quantum fields have infinite degrees of freedom prohibit the exploitation of the elaborated analogy toward demonstrating that the QFT model exhibits the kind of state nonseparability familiar from ordinary quantum mechanics. Still, it is argued that the QFT model does satisfy a rather weak epistemological criterion for state nonseparability.

  8. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel

    2017-01-01

    This textbook is appropriate for use in graduate-level curricula in analog-to-digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters. It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation. This book presents an overview of the state of the art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, third edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 22-nm technology and the need for a more statistical approach to accuracy. Pedagogical enhancements to this edition include additional, new exercises, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate. Considerable background information and practical tips, from designing a PCB, to lay-o...

  9. Mechanical Analogies of Fractional Elements

    Institute of Scientific and Technical Information of China (English)

    HU Kai-Xin; ZHU Ke-Qin

    2009-01-01

    A Fractional element model describes a special kind of viscoelastic material.Its stress is proportional to the fractional-order derivative of strain. Physically the mechanical analogies of fractional elements can be represented by spring-dashpot fractal networks. We introduce a constitutive operator in the constitutive equations of viscoelastic materials.To derive constitutive operators for spring-dashpot fractal networks, we use Heaviside operational calculus, which provides explicit answers not otherwise obtainable simply.Then the series-parallel formulas for the constitutive operator are derived. Using these formulas, a constitutive equation of fractional element with 1/2-order derivative is obtained.Finally we find the way to derive the constitutive equations with other fractional-order derivatives and their mechanical analogies.

  10. Low Power CMOS Analog Multiplier

    Directory of Open Access Journals (Sweden)

    Shipra Sachan

    2015-12-01

    Full Text Available In this paper Low power low voltage CMOS analog multiplier circuit is proposed. It is based on flipped voltage follower. It consists of four voltage adders and a multiplier core. The circuit is analyzed and designed in 0.18um CMOS process model and simulation results have shown that, under single 0.9V supply voltage, and it consumes only 31.8µW quiescent power and 110MHZ bandwidth.

  11. A global analog of Cheshire charge

    CERN Document Server

    McGraw, P

    1994-01-01

    It is shown that a model with a spontaneously broken global symmetry can support defects analogous to Alice strings, and a process analogous to Cheshire charge exchange can take place. A possible realization in superfluid He-3 is pointed out.

  12. Investigating visual analogies for visual insight problems

    OpenAIRE

    Corina Sas; Eric Luchian; Linden Ball

    2010-01-01

    Much research has focused on the impact of analogies in insight problem solving, but less work has investigated how the visual analogies for insight are actually constructed. Thus, it appears that in the search for their facilitative impact on the incubation effect, the understanding of what makes good visual analogies has somehow been lost. This paper presents preliminary work of constructing a set of 6 visual analogies and evaluating their impact on solving the visual problem of eight coins...

  13. Hegel, Analogy, and Extraterrestrial Life

    Science.gov (United States)

    Ross, Joseph T.

    Georg Wilhelm Friedrich Hegel rejected the possibility of life outside of the Earth, according to several scholars of extraterrestrial life. Their position is that the solar system and specifically the planet Earth is the unique place in the cosmos where life, intelligence, and rationality can be. The present study offers a very different interpretation of Hegel's statements about the place of life on Earth by suggesting that, although Hegel did not believe that there were other solar systems where rationality is present, he did in fact suggest that planets in general, not the Earth exclusively, have life and possibly also intelligent inhabitants. Analogical syllogisms are superficial, according to Hegel, insofar as they try to conclude that there is life on the Moon even though there is no evidence of water or air on that body. Similar analogical arguments for life on the Sun made by Johann Elert Bode and William Herschel were considered by Hegel to be equally superficial. Analogical arguments were also used by astronomers and philosophers to suggest that life could be found on other planets in our solar system. Hegel offers no critique of analogical arguments for life on other planets, and in fact Hegel believed that life would be found on other planets. Planets, after all, have meteorological processes and therefore are "living" according to his philosophical account, unlike the Moon, Sun, and comets. Whereas William Herschel was already finding great similarities between the Sun and the stars and had extended these similarities to the property of having planets or being themselves inhabitable worlds, Hegel rejected this analogy. The Sun and stars have some properties in common, but for Hegel one cannot conclude from these similarities to the necessity that stars have planets. Hegel's arguments against the presence of life in the solar system were not directed against other planets, but rather against the Sun and Moon, both of which he said have a different

  14. Analogical Reasoning: A Review of the Literature.

    Science.gov (United States)

    Dawis, Rene V.; Siojo, Luis T.

    The mathematical and philosophical origins of "analogy" are described and their influence on the thinking of intelligence theorists is traced. Theories of intelligence and cognition bearing on analogical reasoning are examined, specifically those of Spearman, Thorndike, Guilford and Piaget. The analogy test item is shown to be a paradigm…

  15. Reasoning by Analogy in Constructing Mathematical Ideas.

    Science.gov (United States)

    English, Lyn D.

    A powerful way of understanding something new is by analogy with something already known. An analogy is defined as a mapping from one structure, which is already known (the base or source), to another structure that is to be inferred or discovered (the target). The research community has given considerable attention to analogical reasoning in the…

  16. SSERVI Analog Regolith Simulant Testbed Facility

    Science.gov (United States)

    Minafra, Joseph; Schmidt, Gregory; Bailey, Brad; Gibbs, Kristina

    2016-10-01

    The Solar System Exploration Research Virtual Institute (SSERVI) at NASA's Ames Research Center in California's Silicon Valley was founded in 2013 to act as a virtual institute that provides interdisciplinary research centered on the goals of its supporting directorates: NASA Science Mission Directorate (SMD) and the Human Exploration & Operations Mission Directorate (HEOMD).Primary research goals of the Institute revolve around the integration of science and exploration to gain knowledge required for the future of human space exploration beyond low Earth orbit. SSERVI intends to leverage existing JSC1A regolith simulant resources into the creation of a regolith simulant testbed facility. The purpose of this testbed concept is to provide the planetary exploration community with a readily available capability to test hardware and conduct research in a large simulant environment.SSERVI's goals include supporting planetary researchers within NASA, other government agencies; private sector and hardware developers; competitors in focused prize design competitions; and academic sector researchers.SSERVI provides opportunities for research scientists and engineers to study the effects of regolith analog testbed research in the planetary exploration field. This capability is essential to help to understand the basic effects of continued long-term exposure to a simulated analog test environment.The current facility houses approximately eight tons of JSC-1A lunar regolith simulant in a test bin consisting of a 4 meter by 4 meter area, including dust mitigation and safety oversight.Facility hardware and environment testing scenarios could include, Lunar surface mobility, Dust exposure and mitigation, Regolith handling and excavation, Solar-like illumination, Lunar surface compaction profile, Lofted dust, Mechanical properties of lunar regolith, Surface features (i.e. grades and rocks)Numerous benefits vary from easy access to a controlled analog regolith simulant testbed, and

  17. Abstract analogical reasoning in high-functioning children with autism spectrum disorders.

    Science.gov (United States)

    Green, Adam E; Kenworthy, Lauren; Mosner, Maya G; Gallagher, Natalie M; Fearon, Edward W; Balhana, Carlos D; Yerys, Benjamin E

    2014-12-01

    Children with autism spectrum disorders (ASD) exhibit a deficit in spontaneously recognizing abstract similarities that are crucial for generalizing learning to new situations. This may contribute to deficits in the development of appropriate schemas for navigating novel situations, including social interactions. Analogical reasoning is the central cognitive mechanism that enables typically developing children to understand abstract similarities between different situations. Intriguingly, studies of high-functioning children with ASD point to a relative cognitive strength in basic, nonabstract forms of analogical reasoning. If this analogical reasoning ability extends to abstract analogical reasoning (i.e., between superficially dissimilar situations), it may provide a bridge between a cognitive capability and core ASD deficits in areas such as generalization and categorization. This study tested whether preserved analogical reasoning abilities in ASD can be extended to abstract analogical reasoning, using photographs of real-world items and situations. Abstractness of the analogies was determined via a quantitative measure of semantic distance derived from latent semantic analysis. Children with ASD performed as well as typically developing children at identifying abstract analogical similarities when explicitly instructed to apply analogical reasoning. Individual differences in abstract analogical reasoning ability predicted individual differences in a measure of social function in the ASD group. Preliminary analyses indicated that children with ASD, but not typically developing children, showed an effect of age on abstract analogical reasoning. These results provide new evidence that children with ASD are capable of identifying abstract similarities through analogical reasoning, pointing to abstract analogical reasoning as a potential lever for improving generalization skills and social function in ASD.

  18. Are all analogies created equal? Prefrontal cortical functioning may predict types of analogical reasoning.

    Science.gov (United States)

    Chrysikou, Evangelia G; Thompson-Schill, Sharon L

    2010-06-01

    Abstract The proposed theory can account for analogies based on learned relationships between elements in the source and target domains. However, its explanatory power regarding the discovery of new relationships during analogical reasoning is limited. We offer an alternative perspective for the role of PFC in analogical thought that may better address different types of analogical mappings.

  19. Sedimentological and geophysical studies of clastic reservoir analogs: Methods, applications and developments of ground-penetrating radar for determination of reservoir geometries in near-surface settings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, G.A.; Soegaard, K.

    1998-05-25

    An integrated sedimentologic and GPR investigation has been carried out on a fluvial channel sandstone in the mid-Cretaceous Ferron Sandstone at Coyote Basin along the southwestern flank of the San Rafael Uplift in east-central Utah. This near-surface study, which covers a area of 40 {times} 16.5 meters to a depth of 15 meters, integrates detailed stratigraphic data from outcrop sections and facies maps with multi-frequency 3-D GPR surveys. The objectives of this investigation are two-fold: (1) to develop new ground-penetrating radar (GPR) technology for imaging shallow subsurface sandstone bodies, and (2) to construct an empirical three-dimensional sandstone reservoir model suitable for hydrocarbon flow-simulation by imaging near-surface sandstone reservoir analogs with the use of GPR. The sedimentological data base consists of a geologic map of the survey area and a detailed facies map of the cliff face immediately adjacent to the survey area. Five vertical sections were measured along the cliff face adjacent to the survey area. In addition, four wells were cored within the survey area from which logs were recorded. In the sections and well logs primary sedimentary structures were documented along with textural information and permeability data. Gamma-ray profiles were also obtained for all sections and core logs. The sedimentologic and stratigraphic information serves as the basis from which much of the processing and interpretation of the GPR data was made. Three 3-D GPR data sets were collected over the survey area at frequencies of 50 MHZ, 100 MHZ, and 200 MHZ.

  20. Analog and mixed-signal electronics

    CERN Document Server

    Stephan, Karl

    2015-01-01

    A practical guide to analog and mixed-signal electronics, with an emphasis on design problems and applications This book provides an in-depth coverage of essential analog and mixed-signal topics such as power amplifiers, active filters, noise and dynamic range, analog-to-digital and digital-to-analog conversion techniques, phase-locked loops, and switching power supplies. Readers will learn the basics of linear systems, types of nonlinearities and their effects, op-amp circuits, the high-gain analog filter-amplifier, and signal generation. The author uses system design examples to motivate

  1. Analog circuit design art, science, and personalities

    CERN Document Server

    Williams, Jim

    1991-01-01

    Analog Circuit Design: Art, Science, and Personalities discusses the many approaches and styles in the practice of analog circuit design. The book is written in an informal yet informative manner, making it easily understandable to those new in the field. The selection covers the definition, history, current practice, and future direction of analog design; the practice proper; and the styles in analog circuit design. The book also includes the problems usually encountered in analog circuit design; approach to feedback loop design; and other different techniques and applications. The text is

  2. Analog modelling of obduction processes

    Science.gov (United States)

    Agard, P.; Zuo, X.; Funiciello, F.; Bellahsen, N.; Faccenna, C.; Savva, D.

    2012-04-01

    Obduction corresponds to one of plate tectonics oddities, whereby dense, oceanic rocks (ophiolites) are presumably 'thrust' on top of light, continental ones, as for the short-lived, almost synchronous Peri-Arabic obduction (which took place along thousands of km from Turkey to Oman in c. 5-10 Ma). Analog modelling experiments were performed to study the mechanisms of obduction initiation and test various triggering hypotheses (i.e., plate acceleration, slab hitting the 660 km discontinuity, ridge subduction; Agard et al., 2007). The experimental setup comprises (1) an upper mantle, modelled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and (2) high-viscosity silicone plates (Rhodrosil Gomme with PDMS iron fillers to reproduce densities of continental or oceanic plates), located at the centre of the tank above the syrup to simulate the subducting and the overriding plates - and avoid friction on the sides of the tank. Convergence is simulated by pushing on a piston at one end of the model with velocities comparable to those of plate tectonics (i.e., in the range 1-10 cm/yr). The reference set-up includes, from one end to the other (~60 cm): (i) the piston, (ii) a continental margin containing a transition zone to the adjacent oceanic plate, (iii) a weakness zone with variable resistance and dip (W), (iv) an oceanic plate - with or without a spreading ridge, (v) a subduction zone (S) dipping away from the piston and (vi) an upper, active continental margin, below which the oceanic plate is being subducted at the start of the experiment (as is known to have been the case in Oman). Several configurations were tested and over thirty different parametric tests were performed. Special emphasis was placed on comparing different types of weakness zone (W) and the extent of mechanical coupling across them, particularly when plates were accelerated. Displacements, together with along-strike and across-strike internal deformation in all

  3. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  4. Transfer Between Analogies: How Solving One Analogy Problem Helps to Solve Another

    OpenAIRE

    Keane, Mark T.

    1995-01-01

    This paper deals with transfer between analogies; with what people acquire from one analogy problem-solving episode that can be re-applied to a subsequent analogy, problem-solving episode. This issue must be resolved if we are to understand the nature of expertise and the appropriate use of analogy in education. There are two main explanations of what subjects acquire from an analogy problem-solving episode. The schema-induction hypothesis maintains that subjects acquire an abs...

  5. Silicon analog components device design, process integration, characterization, and reliability

    CERN Document Server

    El-Kareh, Badih

    2015-01-01

    This book covers modern analog components, their characteristics, and interactions with process parameters. It serves as a comprehensive guide, addressing both the theoretical and practical aspects of modern silicon devices and the relationship between their electrical properties and processing conditions. Based on the authors’ extensive experience in the development of analog devices, this book is intended for engineers and scientists in semiconductor research, development and manufacturing. The problems at the end of each chapter and the numerous charts, figures and tables also make it appropriate for use as a text in graduate and advanced undergraduate courses in electrical engineering and materials science.

  6. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J. M

    2013-01-01

    This textbook is appropriate for use in graduate-level curricula in analog to digital conversion, as well as for practicing engineers in need of a state-of-the-art reference on data converters.  It discusses various analog-to-digital conversion principles, including sampling, quantization, reference generation, nyquist architectures and sigma-delta modulation.  This book presents an overview of the state-of-the-art in this field and focuses on issues of optimizing accuracy and speed, while reducing the power level. This new, second edition emphasizes novel calibration concepts, the specific requirements of new systems, the consequences of 45-nm technology and the need for a more statistical approach to accuracy.  Pedagogical enhancements to this edition include more than twice the exercises available in the first edition, solved examples to introduce all key, new concepts and warnings, remarks and hints, from a practitioner’s perspective, wherever appropriate.  Considerable background information and pr...

  7. Reliability of analog quantum simulation

    Energy Technology Data Exchange (ETDEWEB)

    Sarovar, Mohan [Sandia National Laboratories, Digital and Quantum Information Systems, Livermore, CA (United States); Zhang, Jun; Zeng, Lishan [Shanghai Jiao Tong University, Joint Institute of UMich-SJTU, Key Laboratory of System Control and Information Processing (MOE), Shanghai (China)

    2017-12-15

    Analog quantum simulators (AQS) will likely be the first nontrivial application of quantum technology for predictive simulation. However, there remain questions regarding the degree of confidence that can be placed in the results of AQS since they do not naturally incorporate error correction. Specifically, how do we know whether an analog simulation of a quantum model will produce predictions that agree with the ideal model in the presence of inevitable imperfections? At the same time there is a widely held expectation that certain quantum simulation questions will be robust to errors and perturbations in the underlying hardware. Resolving these two points of view is a critical step in making the most of this promising technology. In this work we formalize the notion of AQS reliability by determining sensitivity of AQS outputs to underlying parameters, and formulate conditions for robust simulation. Our approach naturally reveals the importance of model symmetries in dictating the robust properties. To demonstrate the approach, we characterize the robust features of a variety of quantum many-body models. (orig.)

  8. Comparison between analog and digital filters

    Directory of Open Access Journals (Sweden)

    Zoltan Erdei

    2010-12-01

    Full Text Available Digital signal processing(DSP is one of the most powerful technologies and will model science and engineering in the 21st century. Revolutionary changes have already been made in different areas of research such as communications, medical imaging, radar and sonar technology, high fidelity audio signal reproducing etc. Each of these fields developed a different signal processing technology with its own algorithms, mathematics and technology, Digital filters are used in two general directions: to separate mixed signals and to restore signals that were compromised in different modes. The objective of this paper is to compare some basic digital filters versus analog filters such as low-pass, high-pass, band-pass filters. Scientists and engineers comprehend that, in comparison with analog filters, digital filters can process the same signal in real-time with broader flexibility. This understanding is considered important to instill incentive for engineers to become interested in the field of DSP. The analysis of the results will be made using dedicated libraries in MATLAB and Simulink software, such as the Signal Processing Toolbox.

  9. Therapeutic outlook of pyrazole analogs: A mini review.

    Science.gov (United States)

    Ganguly, Swastika; Sony Jacob, K

    2015-11-19

    Pyrazole is one of the excellent structural motifs in medicinal chemistry. Various physiological and therapeutic possibilities have been exploited by incorporating different pharmacophoric groups in the pyrazole moiety. This has opened a new arena of pyrazole analogs that can be developed into medicinal agents such as anti-inflammatory, analgesic, antipyretic, antiviral, antibacterial, anticancer, anticonvulsant, hypoglycemic, carbonic anhydrase inhibitors, mono amino oxidase (MAO) inhibitors, etc. Though, pyrazole analogs have proven their clinical efficacy as different pharmacological agents, a few of them have been withdrawn from the market due to their side effects. Thus, research on potential new drug candidates bearing the pyrazole moiety with lesser side effects has fairly increased over the last few years. This review explores diverse pharmacological activities exhibited by pyrazole analogs reported recently, which may be of great help for researchers in the area of drug discovery to understand the current scenario of pyrazole based compounds and to design and develop newer drug candidates with improved efficacy.

  10. Water Power Calculator Temperature and Analog Input/Output Module Ambient Temperature Testing

    Energy Technology Data Exchange (ETDEWEB)

    Mark D. McKay

    2011-02-01

    Water Power Calculator Temperature and Analog input/output Module Ambient Temperature Testing A series of three ambient temperature tests were conducted for the Water Power Calculator development using the INL Calibration Laboratory’s Tenney Environmental Chamber. The ambient temperature test results demonstrate that the Moore Industries Temperature Input Modules, Analog Input Module and Analog Output Module, ambient temperature response meet or exceed the manufactures specifications

  11. The analog front-end section of the BaBar silicon vertex tracker readout IC

    Energy Technology Data Exchange (ETDEWEB)

    Manfredi, P.F.; Leona, A.; Mandelli, E.; Re, V.; Svelto, F. [Pavia Univ. (Italy). Dipartimento di Elettronica]|[INFN, Sezione di Pavia, Via Bassi 6, 27100 Pavia (Italy); Kipnis, I.; Luo, L.; Momayezi, M.; Nyman, M.; Pedrali-Noy, M.; Roe, N. [E.O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    1998-02-01

    This paper describes the evolution in the analog section of the vertex detector readout chip for the BaBar experiment. In order to optimize its behaviour, an intermediate chip reproducing the analog part alone was developed and tested. It provided some useful design hints that provided the basis for the final conception of the analog front-end as it is now operational in the complete BaBar chip. (orig.). 6 refs.

  12. Pipeline analog-to-digital converters for wide-band wireless communications

    OpenAIRE

    Sumanen, Lauri

    2002-01-01

    During the last decade, the development of the analog electronics has been dictated by the enormous growth of the wireless communications. Typical for the new communication standards has been an evolution towards higher data rates, which allows more services to be provided. Simultaneously, the boundary between analog and digital signal processing is moving closer to the antenna, thus aiming for a software defined radio. For analog-to-digital converters (ADCs) of radio receivers this indicates...

  13. Pipeline analog-to-digital converters for wide-band wireless communications

    OpenAIRE

    Sumanen, Lauri

    2002-01-01

    During the last decade, the development of the analog electronics has been dictated by the enormous growth of the wireless communications. Typical for the new communication standards has been an evolution towards higher data rates, which allows more services to be provided. Simultaneously, the boundary between analog and digital signal processing is moving closer to the antenna, thus aiming for a software defined radio. For analog-to-digital converters (ADCs) of radio receivers this indicates...

  14. Analog computing by Brewster effect.

    Science.gov (United States)

    Youssefi, Amir; Zangeneh-Nejad, Farzad; Abdollahramezani, Sajjad; Khavasi, Amin

    2016-08-01

    Optical computing has emerged as a promising candidate for real-time and parallel continuous data processing. Motivated by recent progresses in metamaterial-based analog computing [Science343, 160 (2014)SCIEAS0036-807510.1126/science.1242818], we theoretically investigate the realization of two-dimensional complex mathematical operations using rotated configurations, recently reported in [Opt. Lett.39, 1278 (2014)OPLEDP0146-959210.1364/OL.39.001278]. Breaking the reflection symmetry, such configurations could realize both even and odd Green's functions associated with spatial operators. Based on such an appealing theory and by using the Brewster effect, we demonstrate realization of a first-order differentiator. Such an efficient wave-based computation method not only circumvents the major potential drawbacks of metamaterials, but also offers the most compact possible device compared to conventional bulky lens-based optical signal and data processors.

  15. Priming analogical reasoning with false memories.

    Science.gov (United States)

    Howe, Mark L; Garner, Sarah R; Threadgold, Emma; Ball, Linden J

    2015-08-01

    Like true memories, false memories are capable of priming answers to insight-based problems. Recent research has attempted to extend this paradigm to more advanced problem-solving tasks, including those involving verbal analogical reasoning. However, these experiments are constrained inasmuch as problem solutions could be generated via spreading activation mechanisms (much like false memories themselves) rather than using complex reasoning processes. In three experiments we examined false memory priming of complex analogical reasoning tasks in the absence of simple semantic associations. In Experiment 1, we demonstrated the robustness of false memory priming in analogical reasoning when backward associative strength among the problem terms was eliminated. In Experiments 2a and 2b, we extended these findings by demonstrating priming on newly created homonym analogies that can only be solved by inhibiting semantic associations within the analogy. Overall, the findings of the present experiments provide evidence that the efficacy of false memory priming extends to complex analogical reasoning problems.

  16. Long-duration bed rest as an analog to microgravity.

    Science.gov (United States)

    Hargens, Alan R; Vico, Laurence

    2016-04-15

    Long-duration bed rest is widely employed to simulate the effects of microgravity on various physiological systems, especially for studies of bone, muscle, and the cardiovascular system. This microgravity analog is also extensively used to develop and test countermeasures to microgravity-altered adaptations to Earth gravity. Initial investigations of bone loss used horizontal bed rest with the view that this model represented the closest approximation to inactivity and minimization of hydrostatic effects, but all Earth-based analogs must contend with the constant force of gravity by adjustment of the G vector. Later concerns about the lack of similarity between headward fluid shifts in space and those with horizontal bed rest encouraged the use of 6 degree head-down tilt (HDT) bed rest as pioneered by Russian investigators. Headward fluid shifts in space may redistribute bone from the legs to the head. At present, HDT bed rest with normal volunteers is the most common analog for microgravity simulation and to test countermeasures for bone loss, muscle and cardiac atrophy, orthostatic intolerance, and reduced muscle strength/exercise capacity. Also, current physiologic countermeasures are focused on long-duration missions such as Mars, so in this review we emphasize HDT bed rest studies with durations of 30 days and longer. However, recent results suggest that the HDT bed rest analog is less representative as an analog for other important physiological problems of long-duration space flight such as fluid shifts, spinal dysfunction and radiation hazards.

  17. Novel trypanocidal analogs of 5'-(methylthio)-adenosine.

    Science.gov (United States)

    Sufrin, Janice R; Spiess, Arthur J; Marasco, Canio J; Rattendi, Donna; Bacchi, Cyrus J

    2008-01-01

    The purine nucleoside 5'-deoxy-5'-(hydroxyethylthio)-adenosine (HETA) is an analog of the polyamine pathway metabolite 5'-deoxy-5'-(methylthio)-adenosine (MTA). HETA is a lead structure for the ongoing development of selectively targeted trypanocidal agents. Thirteen novel HETA analogs were synthesized and examined for their in vitro trypanocidal activities against bloodstream forms of Trypanosoma brucei brucei LAB 110 EATRO and at least one drug-resistant Trypanosoma brucei rhodesiense clinical isolate. New compounds were also assessed in a cell-free assay for their activities as substrates of trypanosome MTA phosphorylase. The most potent analog in this group was 5'-deoxy-5'-(hydroxyethylthio)-tubercidin, whose in vitro cytotoxicity (50% inhibitory concentration [IC50], 10 nM) is 45 times greater than that of HETA (IC50, 450 nM) against pentamidine-resistant clinical isolate KETRI 269. Structure-activity analyses indicate that the enzymatic cleavage of HETA analogs by trypanosome MTA phosphorylase is not an absolute requirement for trypanocidal activity. This suggests that additional biochemical mechanisms are associated with the trypanocidal effects of HETA and its analogs.

  18. Operational Lessons Learned from NASA Analog Missions

    Science.gov (United States)

    Arnold, Larissa S.

    2010-01-01

    National Aeronautics and Space Administration s (NASA) efforts in human space flight are currently focused on the Space Shuttle and International Space Station (ISS) programs, with efforts beginning on the future exploration opportunities. Both the Space Shuttle and ISS programs are important to the development of a capability for human exploration beyond Low Earth Orbit (LEO). The ISS provides extensive research capabilities to determine how the human body reacts to long duration stays in space. Also, the ISS and Shuttle can serve as a limited testbed for equipment or entire systems that may be used on missions to the Moon, Mars, or to a near-Earth asteroid. It has been nearly 35 years since the Apollo astronauts visited the Moon. Future space explorers will have to re-learn how to work and live on planetary surfaces, and how to do that for extended periods of time. Exploration crews will perform a wide assortment of scientific tasks, including material sampling and emplacement of automated instruments. Surface mission operations include the activities of the crew living and working, mission support from the Earth, and the operation of robotic and other remotely commanded equipment on the surface and in planetary orbit. Other surface activities will include the following: exploring areas surrounding a habitat; using rovers to collect rock and soil samples; setting up experiments on the surface to monitor the radiation environment and any seismic or thermal activity; and conducting scientific analyses and experiments inside a habitat laboratory. Of course, the astronauts will also have to spend some of their surface time "doing chores" and maintaining their habitat and other systems. In preparation for future planetary exploration, NASA must design the answers to many operational questions. What will the astronauts do on the surface? How will they accomplish this? What tools will they require for their tasks? How will robots and astronauts work together? What

  19. The Resilience of Analog Tools in Creative Work Practices

    DEFF Research Database (Denmark)

    Borum, Nanna; Petersson, Eva; Frimodt-Møller, Søren

    2014-01-01

    This paper discusses the use of digital and analog tools, respectively, in a creative industry. The research was done within the EU-funded research project IdeaGarden, which explores digital platforms for creative collaboration. The findings in a case study of LEGO® Future Lab, one of LEGO Group......’s largest innovation departments, show a preference for analog tools over digital in the creative process. This points towards a general need for tangible tools in the creative work process, a need that has consequences for the development of new digital tools for creative collaboration....

  20. RADIATION HARDENED ANALOG IC FOR SENSOR

    Directory of Open Access Journals (Sweden)

    O. V. Dvornikov

    2011-01-01

    Full Text Available Problems of specialized analog integrated circuit design for sensor equipments are considered. It is offered to produce of radiation hardened analog IC on structured chips for economic efficiency at small production volume. The approach to analog IC design is described, including recommendations for choice of: types and quantities of structured chip analogue components; active and passive components; schematic decisions of analogue components with programmed parameters and small sensitivity to radiation. 

  1. Design and Analysis of Reconfigurable Analog System

    Science.gov (United States)

    2011-02-01

    34010010" �" �" �" �" �" �" �±" N3 N2 N± P1 P2 P3 * Current sources $RR = 1; *Ramp Rate (slope of the...2008/12/12/31e83bac-500f-4182- acca -4d360295fd9c.pdf, Analog Devices, Analog Dialogue 39-06, June 2005. [15] D. A. Johns, K. Martin "Analog Integrated

  2. Synthesis and biological activity of Wuweizisu C and analogs.

    Science.gov (United States)

    Chang, J B; Wang, Q; Li, Y F

    2009-01-01

    Lignans are widely distributed in nature. The earliest recorded medicinal use of lignans dated back to over 1000 years ago. Lignan-rich plant products were also active ingredients in Chinese and Japanese folk medicines for the treatment of various diseases. The dried root and stem of this plant are listed in the Chinese pharmacopoeia for the treatment of rheumatoid arthritis, gastric, duodenal ulcers and many other diseases. This review highlights synthetic strategies for the Wuweizisu C analogs and the important pharmacological activities as well as therapeutic findings related to the treatment of HBV and other diseases. Notably a significant and ongoing project on Wuweizisu C and its analogs has led to the discovery and development of two potent derivatives alpha-DDB and BICYCLOL which are currently in clinical trials against HBV, especially in lowering elevated SGPT levels. Further design, synthesis, and evaluation of Wuweizisu C analogs are discussed.

  3. Integrating Problem Solvers from Analogous Markets in New Product Ideation

    DEFF Research Database (Denmark)

    Franke, Nikolaus; Poetz, Marion; Schreier, Martin

    2014-01-01

    Who provides better inputs to new product ideation tasks, problem solvers with expertise in the area for which new products are to be developed or problem solvers from “analogous” markets that are distant but share an analogous problem or need? Conventional wisdom appears to suggest that target...... that including problem solvers from analogous markets versus the target market accounts for almost two-thirds of the well-known effect of involving lead users instead of average problem solvers. This effect is further amplified when the analogous distance between the markets increases, i.e., when searching...... market expertise is indispensable, which is why most managers searching for new ideas tend to stay within their own market context even when they do search outside their firms' boundaries. However, in a unique symmetric experiment that isolates the effect of market origin, we find evidence...

  4. Ethnographic analogy, the comparative method, and archaeological special pleading.

    Science.gov (United States)

    Currie, Adrian

    2016-02-01

    Ethnographic analogy, the use of comparative data from anthropology to inform reconstructions of past human societies, has a troubled history. Archaeologists often express concern about, or outright reject, the practice--and sometimes do so in problematically general terms. This is odd, as (or so I argue) the use of comparative data in archaeology is the same pattern of reasoning as the 'comparative method' in biology, which is a well-developed and robust set of inferences which play a central role in discovering the biological past. In pointing out this continuity, I argue that there is no 'special pleading' on the part of archaeologists in this regard: biologists must overcome analogous epistemic difficulties in their use of comparative data. I then go on to emphasize the local, empirically tractable ways in which particular ethnographic analogies may be licensed.

  5. Practice Utilization of Algorithms for Analog Filter Group Delay Optimization

    Directory of Open Access Journals (Sweden)

    K. Hajek

    2007-04-01

    Full Text Available This contribution deals with an application of three different algorithms which optimize a group delay of analog filters. One of them is a part of the professional circuit simulator Micro Cap 7 and the others two original algorithms are developed in the MATLAB environment. An all-pass network is used to optimize the group delay of an arbitrary analog filter. Introduced algorithms look for an optimal order and optimal coefficients of an all-pass network transfer function. Theoretical foundations are introduced and all algorithms are tested using the optimization of testing analog filter. The optimization is always run three times because the second, third and fourth-order all-pass network is used. An equalization of the original group delay is a main objective of these optimizations. All outputs of all algorithms are critically evaluated and also described.

  6. A hybrid digital-analog long pulse integrator

    Science.gov (United States)

    Strait, E. J.; Broesch, J. D.; Snider, R. T.; Walker, M. L.

    1997-01-01

    A digital-analog integrator has been developed for use with inductive magnetic sensors in long-pulse tokamaks. Continuous compensation of input offsets is accomplished by alternating analog-to-digital convertor samples from the sensor and a dummy load, while a RC network provides passive integration between samples. Typically a sampling rate of 10 kHz is used. In operational tests on the DIII-D tokamak, digital and analog integration of tokamak data show good agreement. The output drift error during a 1200 s integration interval corresponds to a few percent of the anticipated signal for poloidal field probes in International Thermonuclear Experimental Reactor, and bench tests suggest that the error can be reduced further.

  7. Analog VLSI neural network integrated circuits

    Science.gov (United States)

    Kub, F. J.; Moon, K. K.; Just, E. A.

    1991-01-01

    Two analog very large scale integration (VLSI) vector matrix multiplier integrated circuit chips were designed, fabricated, and partially tested. They can perform both vector-matrix and matrix-matrix multiplication operations at high speeds. The 32 by 32 vector-matrix multiplier chip and the 128 by 64 vector-matrix multiplier chip were designed to perform 300 million and 3 billion multiplications per second, respectively. An additional circuit that has been developed is a continuous-time adaptive learning circuit. The performance achieved thus far for this circuit is an adaptivity of 28 dB at 300 KHz and 11 dB at 15 MHz. This circuit has demonstrated greater than two orders of magnitude higher frequency of operation than any previous adaptive learning circuit.

  8. Disease Resistance Gene Analogs (RGAs in Plants

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Sekhwal

    2015-08-01

    Full Text Available Plants have developed effective mechanisms to recognize and respond to infections caused by pathogens. Plant resistance gene analogs (RGAs, as resistance (R gene candidates, have conserved domains and motifs that play specific roles in pathogens’ resistance. Well-known RGAs are nucleotide binding site leucine rich repeats, receptor like kinases, and receptor like proteins. Others include pentatricopeptide repeats and apoplastic peroxidases. RGAs can be detected using bioinformatics tools based on their conserved structural features. Thousands of RGAs have been identified from sequenced plant genomes. High-density genome-wide RGA genetic maps are useful for designing diagnostic markers and identifying quantitative trait loci (QTL or markers associated with plant disease resistance. This review focuses on recent advances in structures and mechanisms of RGAs, and their identification from sequenced genomes using bioinformatics tools. Applications in enhancing fine mapping and cloning of plant disease resistance genes are also discussed.

  9. Disease Resistance Gene Analogs (RGAs) in Plants.

    Science.gov (United States)

    Sekhwal, Manoj Kumar; Li, Pingchuan; Lam, Irene; Wang, Xiue; Cloutier, Sylvie; You, Frank M

    2015-08-14

    Plants have developed effective mechanisms to recognize and respond to infections caused by pathogens. Plant resistance gene analogs (RGAs), as resistance (R) gene candidates, have conserved domains and motifs that play specific roles in pathogens' resistance. Well-known RGAs are nucleotide binding site leucine rich repeats, receptor like kinases, and receptor like proteins. Others include pentatricopeptide repeats and apoplastic peroxidases. RGAs can be detected using bioinformatics tools based on their conserved structural features. Thousands of RGAs have been identified from sequenced plant genomes. High-density genome-wide RGA genetic maps are useful for designing diagnostic markers and identifying quantitative trait loci (QTL) or markers associated with plant disease resistance. This review focuses on recent advances in structures and mechanisms of RGAs, and their identification from sequenced genomes using bioinformatics tools. Applications in enhancing fine mapping and cloning of plant disease resistance genes are also discussed.

  10. Analogy between fluid cavitation and fracture mechanics

    Science.gov (United States)

    Hendricks, R. C.; Mullen, R. L.; Braun, M. J.

    1983-01-01

    When the stresses imposed on a fluid are sufficiently large, rupture or cavitation can occur. Such conditions can exist in many two-phase flow applications, such as the choked flows, which can occur in seals and bearings. Nonspherical bubbles with large aspect ratios have been observed in fluids under rapid acceleration and high shear fields. These bubbles are geometrically similar to fracture surface patterns (Griffith crack model) existing in solids. Analogies between crack growth in solid and fluid cavitation are proposed and supported by analysis and observation (photographs). Healing phenomena (void condensation), well accepted in fluid mechanics, have been observed in some polymers and hypothesized in solid mechanics. By drawing on the strengths of the theories of solid mechanics and cavitation, a more complete unified theory can be developed.

  11. Fermilab accelerator control system: Analog monitoring facilities

    Energy Technology Data Exchange (ETDEWEB)

    Seino, K.; Anderson, L.; Smedinghoff, J.

    1987-10-01

    Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system.

  12. Robust hyperchaotic synchronization via analog transmission line

    Science.gov (United States)

    Sadoudi, S.; Tanougast, C.

    2016-02-01

    In this paper, a novel experimental chaotic synchronization technique via analog transmission is discussed. We demonstrate through Field-Programmable Gate Array (FPGA) implementation design the robust synchronization of two embedded hyperchaotic Lorenz generators interconnected with an analog transmission line. The basic idea of this work consists in combining a numerical generation of chaos and transmitting it with an analog signal. The numerical chaos allows to overcome the callback parameter mismatch problem and the analog transmission offers robust data security. As application, this technique can be applied to all families of chaotic systems including time-delayed chaotic systems.

  13. Application of natural analog studies to exploration for ore deposits

    Energy Technology Data Exchange (ETDEWEB)

    Gustafson, D.L. [Consulting Economic Geologist, Reno, NV (United States)

    1995-09-01

    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure.

  14. The Nitty Gritty: How We Make Analogs Work

    Science.gov (United States)

    Self, A. L.; Huppman, S. R.; Spence, L. A.

    2017-01-01

    NASA's Human Research Program (HRP) is becoming increasingly reliant on Isolated, Confined and Controlled (ICC) analogs to accomplish many of its research objectives. Compared to other research platforms, ICC analogs present a unique set of operational challenges that must be addressed in order to ensure a high fidelity research environment. In particular, the Human Exploration Research Analog (HERA) habitat, which is classified as an ICC environment, has been developed over the past three years to accommodate the operational needs of research investigations from each of the HRP Elements. During the development period, various types of requirements have contributed to the current operational model, which strives to achieve the highest possible level of mission fidelity with limited resources. This presentation will focus on the operational aspects of the HERA habitat, with emphasis on how we develop the analog research environment to meet researchers' needs. Specific discussion topics include mission scenario development, operational tasks, mission timeline integration, stressor implementation, console support, and improvements based on lessons learned. The information is intended to help investigators better understand the details behind HERA operations and the benefits to their research goals.

  15. Synthesis, bioanalysis and pharmacology of nucleoside and nucleotide analogs

    NARCIS (Netherlands)

    Jansen, R.S.

    2009-01-01

    Nucleoside analogs are an important class of drugs in anticancer and antiviral therapy. The compounds are, however, only active after intracellular conversion to their mono-, di- and triphosphate nucleotide form. In this thesis the development of sensitive liquid chromatography coupled to tandem mas

  16. Precision-analog fiber-optic transmission system

    Energy Technology Data Exchange (ETDEWEB)

    Stover, G.

    1981-06-01

    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters.

  17. Dutch Plural Inflection: The Exception that Proves the Analogy

    Science.gov (United States)

    Keuleers, Emmanuel; Sandra, Dominiek; Daelemans, Walter; Gillis, Steven; Durieux, Gert; Martens, Evelyn

    2007-01-01

    We develop the view that inflection is driven partly by non-phonological analogy and that non-phonological information is of particular importance to the inflection of non-canonical roots, which in the view of [Marcus, G. F., Brinkmann, U., Clahsen, H., Wiese, R., & Pinker, S. (1995). "German inflection: the exception that proves the rule."…

  18. From specification to measurement: the bottleneck in analog industrial testing

    NARCIS (Netherlands)

    Rijsinge, van R.J.; Haggenburg, A.A.R.M.; Vries, de C.; Wallinga, H.

    1990-01-01

    The translation of the specification of an analog device into the necessary set of measurements to be carried out by an industrial test facility is discussed. Algorithms are developed to compute the number of test vectors needed to guarantee a certain parameter and to compare several possible test m

  19. The sugar ring of the nucleoside is required for productive substrate positioning in the active site of human deoxycytidine kinase (dCK): implications for the development of dCK-activated acyclic guanine analogs

    Science.gov (United States)

    Hazra, Saugata; Konrad, Manfred; Lavie, Arnon

    2010-01-01

    The low toxicity of acyclovir (ACV) is mainly due to the fact that human nucleoside kinases have undetectable phosphorylation rates with this acyclic guanine analog. In contrast, herpes virus thymidine kinase (HSV1-TK) readily activates ACV. We wanted to understand why human deoxycytidine kinase (dCK), which is related to HSV1-TK and phosphorylates deoxyguanosine, does not accept acyclic guanine analogs as substrates. Therefore, we crystallized dCK in complex with ACV at the nucleoside phosphoryl acceptor site, and UDP at the phosphoryl donor site. The structure reveals that while ACV does bind at the dCK active site, it does so adopting a non-productive conformation. Despite binding ACV, the enzyme remains in the open, inactive state. In comparison to ACV binding to HSV1-TK, in dCK the nucleoside base adopts a different orientation related by about a 60 degree rotation. Our analysis suggests that dCK would phosphorylate acyclic guanine analogs if they can induce a similar rotation. PMID:20684612

  20. Expert analogy use in a naturalistic setting

    Science.gov (United States)

    Kretz, Donald R.; Krawczyk, Daniel C.

    2014-01-01

    The use of analogy is an important component of human cognition. The type of analogy we produce and communicate depends heavily on a number of factors, such as the setting, the level of domain expertise present, and the speaker's goal or intent. In this observational study, we recorded economics experts during scientific discussion and examined the categorical distance and structural depth of the analogies they produced. We also sought to characterize the purpose of the analogies that were generated. Our results supported previous conclusions about the infrequency of superficial similarity in subject-generated analogs, but also showed that distance and depth characteristics were more evenly balanced than in previous observational studies. This finding was likely due to the nature of the goals of the participants, as well as the broader nature of their expertise. An analysis of analogical purpose indicated that the generation of concrete source examples of more general target concepts was most prevalent. We also noted frequent instances of analogies intended to form visual images of source concepts. Other common purposes for analogies were the addition of colorful speech, inclusion (i.e., subsumption) of a target into a source concept, or differentiation between source and target concepts. We found no association between depth and either of the other two characteristics, but our findings suggest a relationship between purpose and distance; i.e., that visual imagery typically entailed an outside-domain source whereas exemplification was most frequently accomplished using within-domain analogies. Overall, we observed a rich and diverse set of spontaneously produced analogical comparisons. The high degree of expertise within the observed group along with the richly comparative nature of the economics discipline likely contributed to this analogical abundance. PMID:25505437

  1. Automatic Synthesis of CMOS Algorithmic Analog To-Digital Converter.

    Science.gov (United States)

    Jusuf, Gani

    The steady decrease in technological feature size is allowing increasing levels of integration in analog/digital interface functions. These functions consist of analog as well as digital circuits. While the turn around time for an all digital IC chip is very short due to the maturity of digital IC computer-aided design (CAD) tools over the last ten years, most analog circuits have to be designed manually due to the lack of analog IC CAD tools. As a result, analog circuit design becomes the bottleneck in the design of mixed signal processing chips. One common analog function in a mixed signal processing chip is an analog-to-digital conversion (ADC) function. This function recurs frequently but with varying performance requirements. The objective of this research is to study the design methodology of a compilation program capable of synthesizing ADC's with a broad range of sampling rates and resolution, and silicon area and performance comparable with the manual approach. The automatic compilation of the ADC function is a difficult problem mainly because ADC techniques span such a wide spectrum of performance, with radically different implementations being optimum for different ranges of conversion range, resolution, and power dissipation. We will show that a proper choice of the ADC architectures and the incorporation of many analog circuit design techniques will simplify the synthesis procedure tremendously. Moreover, in order to speed up the device sizing, hierarchical optimization procedure and behavioral simulation are implemented into the ADC module generation steps. As a result of this study, a new improved algorithmic ADC without the need of high precision comparators has been developed. This type of ADC lends itself to automatic generation due to its modularity, simplicity, small area consumption, moderate speed, low power dissipation, and single parameter trim capability that can be added at high resolution. Furthermore, a performance-driven CMOS ADC module

  2. A Mechanical Analogy for the Photoelectric Effect

    Science.gov (United States)

    Kovacevic, Milan S.; Djordjevich, Alexandar

    2006-01-01

    Analogy is a potent tool in the teacher's repertoire. It has been particularly well recognized in the teaching of science. However, careful planning is required for its effective application to prevent documented drawbacks when analogies are stretched too far. Befitting the occasion of the World Year of Physics commemorating Albert Einstein's 1905…

  3. Analogies in high school Brazilian chemistry textbooks

    Directory of Open Access Journals (Sweden)

    Rosária Justi

    2000-05-01

    Full Text Available This paper presents and discusses an analysis of the analogies presented by Brazilian chemistry textbooks for the medium level. The main aim of the analysis is to discuss whether such analogies can be said good teaching models. From the results, some aspects concerning with teachers' role are discussed. Finally, some new research questions are emphasised.

  4. PEMETAAN ANALOGI PADA KONSEP ABSTRAK FISIKA

    Directory of Open Access Journals (Sweden)

    Nyoto Suseno

    2014-11-01

    Full Text Available The research of any where founded majority students have common difficulties in abstract physics concept. The result of observation, lecturers have problem  in teaching implementation of abstract concepts on physics learning. The objective of this research is to find out the ways how to overcome this problem. The research place of  physics education programs and senior high school. The data are colected by quetionere, observation and interview. The lecturer behavior to making out this case is use of analogy to make concrete a abstract concept. This action is true, because the analogies are dynamic tools that facilitate understanding, rather than representations of the correct and static explanations. Using analogies not only promoted profound understanding of abstract concept, but also helped students overcome their misconceptions. However used analogy in teaching not yet planed with seriousness, analogy used spontanously with the result that less optimal. By planing and selecting right analogy, the role of analogy can be achieved the optimal result. Therefore, it is important to maping analogies of abstract consepts on physics learning.

  5. Response Generation Norms for Verbal Analogies.

    Science.gov (United States)

    Ingram, Albert; Pellegrino, James W.

    Normative data were collected for the generation of responses to 150 incomplete verbal analogies. Two types of normative data are provided: (a) the probabilities associated with each response produced for each analogy base and (b) the probabilities that initial responses represented the appropriate semantic relationship, with a division of…

  6. The Multidimensionality of Verbal Analogy Items

    Science.gov (United States)

    Ullstadius, Eva; Carlstedt, Berit; Gustafsson, Jan-Eric

    2008-01-01

    The influence of general and verbal ability on each of 72 verbal analogy test items were investigated with new factor analytical techniques. The analogy items together with the Computerized Swedish Enlistment Battery (CAT-SEB) were given randomly to two samples of 18-year-old male conscripts (n = 8566 and n = 5289). Thirty-two of the 72 items had…

  7. Antibacterial and Antibiofilm Activities of Makaluvamine Analogs

    Directory of Open Access Journals (Sweden)

    Bhavitavya Nijampatnam

    2014-09-01

    Full Text Available Streptococcus mutans is a key etiological agent in the formation of dental caries. The major virulence factor is its ability to form biofilms. Inhibition of S. mutans biofilms offers therapeutic prospects for the treatment and the prevention of dental caries. In this study, 14 analogs of makaluvamine, a marine alkaloid, were evaluated for their antibacterial activity against S. mutans and for their ability to inhibit S. mutans biofilm formation. All analogs contained the tricyclic pyrroloiminoquinone core of makaluvamines. The structural variations of the analogs are on the amino substituents at the 7-position of the ring and the inclusion of a tosyl group on the pyrrole ring N of the makaluvamine core. The makaluvamine analogs displayed biofilm inhibition with IC50 values ranging from 0.4 μM to 88 μM. Further, the observed bactericidal activity of the majority of the analogs was found to be consistent with the anti-biofilm activity, leading to the conclusion that the anti-biofilm activity of these analogs stems from their ability to kill S. mutans. However, three of the most potent N-tosyl analogs showed biofilm IC50 values at least an order of magnitude lower than that of bactericidal activity, indicating that the biofilm activity of these analogs is more selective and perhaps independent of bactericidal activity.

  8. Compressed Sensing of Analog Signals

    CERN Document Server

    Eldar, Yonina C

    2008-01-01

    A traditional assumption underlying most data converters is that the signal should be sampled at a rate which exceeds twice the highest frequency. This statement is based on a worst-case scenario in which the signal occupies the entire available bandwidth. In practice, many signals posses a sparse structure so that a large part of the bandwidth is not exploited. In this paper, we consider a framework for utilizing this sparsity in order to sample such analog signals at a low rate. More specifically, we consider continuous-time signals that lie in a shift-invariant (SI) space generated by m kernels, so that any signal in the space can be expressed as an infinite linear combination of the shifted kernels. If the period of the underlying SI space is equal to T, then such signals can be perfectly reconstructed from samples at a rate of m/T. Here we treat the case in which only k out of the m generators are active, meaning that the signal actually lies in a lower dimensional space spanned by k generators. However,...

  9. An optical analog signal transmitter

    Energy Technology Data Exchange (ETDEWEB)

    Fudzita, K.; Itida, T.; Tanaka, Kh.

    1984-01-11

    An optical laser analog signal transmitter employing an amplitude modulated subcarrier is patented; this transmitter performs stable and high quality transmission of information signals over great distances. A feature of the proposed transmitter is a special transmitter operational mode in which the light emission reflected off the connection point to the fiber optic conduit is sent back to the laser diode in a transient period. As a result, the critical mode of the generated emission is not influenced by the reflected signal. The transmitter consists of a laser diode with biasing near the cutoff point, an amplitude modulator with a subcarrier frequency oscillator, a section of flexible fiber-optic cable of length L, which connects the laser diode to the primary optical fiber conduit, and the connector itself. The subcarrier frequency may vary over wide ranges to establish the necessary correlation between the length of the light conduit section L and the return propagation time of the reflected light signal from the connection point to the laser diode. The difference between the lasing time of the light signal and the return time to the laser diode of the signal reflected off the connector is determined by the relation tau equals 2nL/c - mtauc, where L is the length of the connecting section; n is the refractivity of the optical fiber; c is the velocity of light; tauc is the period of the high frequency subcarrier signal; and m is an integer.

  10. Pterostilbene, a Potent Analog of Resveratrol, a Therapeutic Agent in Prostate Cancer: Epigenetic Mechanisms of Action

    Science.gov (United States)

    2015-10-01

    efficacy in prostate cancer. Resveratrol analogs with better bioavailability, conferring superior pharmacological potencies and greater anticancer ...metabolism, natural resveratrol analogs with improved pharma- cokinetic properties and pharmacological potency hold greater promise as natural product drugs ...models have greatly contributed to the basic understanding of cancer mechanisms and anticancer drug discovery.47–49 We have developed several prostate

  11. Analogy-Integrated e-Learning Module: Facilitating Students' Conceptual Understanding

    Science.gov (United States)

    Florida, Jennifer

    2012-01-01

    The study deals with the development of an analogy-integrated e-learning module on Cellular Respiration, which is intended to facilitate conceptual understanding of students with different brain hemisphere dominance and learning styles. The module includes eight analogies originally conceptualized following the specific steps used to prepare…

  12. Embedding Analogical Reasoning into 5E Learning Model: A Study of the Solar System

    Science.gov (United States)

    Devecioglu-Kaymakci, Yasemin

    2016-01-01

    The purpose of this study was to investigate how the 5E learning model affects learning about the Solar System when an analogical model is utilized in teaching. The data were gathered in an urban middle school 7th grade science course while teaching relevant astronomy topics. The analogical model developed by the researchers was administered to 20…

  13. Analogy-Integrated e-Learning Module: Facilitating Students' Conceptual Understanding

    Science.gov (United States)

    Florida, Jennifer

    2012-01-01

    The study deals with the development of an analogy-integrated e-learning module on Cellular Respiration, which is intended to facilitate conceptual understanding of students with different brain hemisphere dominance and learning styles. The module includes eight analogies originally conceptualized following the specific steps used to prepare…

  14. Embedding Analogical Reasoning into 5E Learning Model: A Study of the Solar System

    Science.gov (United States)

    Devecioglu-Kaymakci, Yasemin

    2016-01-01

    The purpose of this study was to investigate how the 5E learning model affects learning about the Solar System when an analogical model is utilized in teaching. The data were gathered in an urban middle school 7th grade science course while teaching relevant astronomy topics. The analogical model developed by the researchers was administered to 20…

  15. Demonstrative and non-demonstrative reasoning by analogy

    OpenAIRE

    Ippoliti, Emiliano

    2008-01-01

    The paper analizes a set of issues related to analogy and analogical reasoning, namely: 1) The problem of analogy and its duplicity; 2) The role of analogy in demonstrative reasoning; 3) The role of analogy in non-demonstrative reasoning; 4) The limits of analogy; 5) The convergence, particularly in multiple analogical reasoning, of these two apparently distinct aspects and its methodological and philosophical consequences. The paper, using example from number theory, argues for an heuristc c...

  16. Computational approaches to analogical reasoning current trends

    CERN Document Server

    Richard, Gilles

    2014-01-01

    Analogical reasoning is known as a powerful mode for drawing plausible conclusions and solving problems. It has been the topic of a huge number of works by philosophers, anthropologists, linguists, psychologists, and computer scientists. As such, it has been early studied in artificial intelligence, with a particular renewal of interest in the last decade. The present volume provides a structured view of current research trends on computational approaches to analogical reasoning. It starts with an overview of the field, with an extensive bibliography. The 14 collected contributions cover a large scope of issues. First, the use of analogical proportions and analogies is explained and discussed in various natural language processing problems, as well as in automated deduction. Then, different formal frameworks for handling analogies are presented, dealing with case-based reasoning, heuristic-driven theory projection, commonsense reasoning about incomplete rule bases, logical proportions induced by similarity an...

  17. A dark business, full of shadows: analogy and theology in William Harvey.

    Science.gov (United States)

    Goldberg, Benjamin

    2013-09-01

    In a short work called De conceptione appended to the end of his Exercitationes de generatione animalium (1651), William Harvey developed a rather strange analogy. To explain how such marvelous productions as living beings were generated from the rather inauspicious ingredients of animal reproduction, Harvey argued that conception in the womb was like conception in the brain. It was mostly rejected at the time; it now seems a ludicrous theory based upon homonymy. However, this analogy offers insight into the structure and function of analogies in early modern natural philosophy. In this essay I hope to not only describe the complex nature of Harvey's analogy, but also offer a novel interpretation of his use of analogical reasoning, substantially revising the account offered by Guido Giglioni (1993). I discuss two points of conceptual change and negotiation in connection with Harvey's analogy, understanding it as both a confrontation between the border of the natural and the supernatural, as well as a moment in the history of psychology. My interpretation touches upon a number of important aspects, including why the analogy was rejected, how Harvey systematically deployed analogies according to his notions of natural philosophical method, how the analogy fits into contemporary discussions of analogies in science, and finally, how the analogy must be seen in the context of changing Renaissance notions of the science of the soul, ultimately confronting the problem of how to understand final causality in Aristotelian science. In connection with the last, I conclude the essay by turning to how Harvey embeds the analogy within a natural theological cosmology.

  18. An Analog Earth Climate Model

    Science.gov (United States)

    Varekamp, J. C.

    2010-12-01

    The earth climate is broadly governed by the radiative power of the sun as well as the heat retention and convective cooling of the atmosphere. I have constructed an analog earth model for an undergraduate climate class that simulates mean climate using these three parameters. The ‘earth’ is a hollow, black, bronze sphere (4 cm diameter) mounted on a thin insulated rod, and illuminated by two opposite optic fibers, with light focused on the sphere by a set of lenses. The sphere is encased in a large double-walled aluminum cylinder (34 cm diameter by 26 cm high) with separate water cooling jackets at the top, bottom, and sides. The cylinder can be filled with a gas of choice at a variety of pressures or can be run in vacuum. The exterior is cladded with insulation, and the temperature of the sphere, atmosphere and walls is monitored with thermocouples. The temperature and waterflow of the three cooling jackets can be monitored to establish the energy output of the whole system; the energy input is the energy yield of the two optic fibers. A small IR transmissive lens at the top provides the opportunity to hook up the fiber of a hyper spectrometer to monitor the emission spectrum of the black ‘earth’ sphere. A pressure gauge and gas inlet-outlet system for flushing of the cell completes it. The heat yield of the cooling water at the top is the sum of the radiative and convective components, whereas the bottom jacket only carries off the radiative heat of the sphere. Undergraduate E&ES students at Wesleyan University have run experiments with dry air, pure CO2, N2 and Ar at 1 atmosphere, and a low vacuum run was accomplished to calibrate the energy input. For each experiment, the lights are flipped on, the temperature acquisition routine is activated, and the sphere starts to warm up until an equilibrium temperature has been reached. The lights are then flipped off and the cooling sequence towards ambient is registered. The energy input is constant for a given

  19. Natural CO2 Analogs for Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Scott H. Stevens; B. Scott Tye

    2005-07-31

    The report summarizes research conducted at three naturally occurring geologic CO{sub 2} fields in the US. The fields are natural analogs useful for the design of engineered long-term storage of anthropogenic CO{sub 2} in geologic formations. Geologic, engineering, and operational databases were developed for McElmo Dome in Colorado; St. Johns Dome in Arizona and New Mexico; and Jackson Dome in Mississippi. The three study sites stored a total of 2.4 billion t (46 Tcf) of CO{sub 2} equivalent to 1.5 years of power plant emissions in the US and comparable in size with the largest proposed sequestration projects. The three CO{sub 2} fields offer a scientifically useful range of contrasting geologic settings (carbonate vs. sandstone reservoir; supercritical vs. free gas state; normally pressured vs. overpressured), as well as different stages of commercial development (mostly undeveloped to mature). The current study relied mainly on existing data provided by the CO{sub 2} field operator partners, augmented with new geochemical data. Additional study at these unique natural CO{sub 2} accumulations could further help guide the development of safe and cost-effective design and operation methods for engineered CO{sub 2} storage sites.

  20. Analog regulation of metabolic demand

    Directory of Open Access Journals (Sweden)

    Muskhelishvili Georgi

    2011-03-01

    Full Text Available Abstract Background The 3D structure of the chromosome of the model organism Escherichia coli is one key component of its gene regulatory machinery. This type of regulation mediated by topological transitions of the chromosomal DNA can be thought of as an analog control, complementing the digital control, i.e. the network of regulation mediated by dedicated transcription factors. It is known that alterations in the superhelical density of chromosomal DNA lead to a rich pattern of differential expressed genes. Using a network approach, we analyze these expression changes for wild type E. coli and mutants lacking nucleoid associated proteins (NAPs from a metabolic and transcriptional regulatory network perspective. Results We find a significantly higher correspondence between gene expression and metabolism for the wild type expression changes compared to mutants in NAPs, indicating that supercoiling induces meaningful metabolic adjustments. As soon as the underlying regulatory machinery is impeded (as for the NAP mutants, this coherence between expression changes and the metabolic network is substantially reduced. This effect is even more pronounced, when we compute a wild type metabolic flux distribution using flux balance analysis and restrict our analysis to active reactions. Furthermore, we are able to show that the regulatory control exhibited by DNA supercoiling is not mediated by the transcriptional regulatory network (TRN, as the consistency of the expression changes with the TRN logic of activation and suppression is strongly reduced in the wild type in comparison to the mutants. Conclusions So far, the rich patterns of gene expression changes induced by alterations of the superhelical density of chromosomal DNA have been difficult to interpret. Here we characterize the effective networks formed by supercoiling-induced gene expression changes mapped onto reconstructions of E. coli's metabolic and transcriptional regulatory network. Our

  1. Namibian Analogs To Titan Dunes

    Science.gov (United States)

    Wall, Stephen D.; Lopes, R.; Kirk, R.; Stofan, E.; Farr, T.; Van der Ploeg, P.; Lorenz, R.; Radebaugh, J.

    2009-09-01

    Titan's equatorial dunes, observed in Cassini SAR, have been described as longitudinal, similar to longitudinal dunes in the Namib sand sea in southern Africa. Their "Y” junctions and the way they divert around topography are used as evidence of equatorial wind flow direction. In two instances of such diversion they exhibit overlying or crosshatched patterns in two distinct directions that have been interpreted as a transition to transverse dunes. Here we describe field observations of the Namibian dunes and these comparisons, we present images of the dunes from terrestrial SAR missions, and we discuss implications to both the Titan dunes and the wind regime that created them. Selected portions of the Namibian dunes resemble Titan's dunes in peak-to-peak distance and length. They are morphologically similar to Titan, and specific superficial analogs are common, but they also differ. For example, when Titan dunes encounter topography they either terminate abruptly, "climb” the upslope, or divert around; only the latter behavior is seen in remote sensing images of Namibia. Namib linear dunes do transition to transverse as they divert, but at considerably smaller wavelength, while at Titan the wavelengths are of the same scale. Crosshatching of similar-wavelength dunes does occur in Namibia, but not near obstacles. Many additional aeolian features that are seen at Namibia such as star dunes, serpentine ridges and scours have not been detected on Titan, although they might be below the Cassini SAR's 300-m resolution. These similarities and differences allow us to explore mechanisms of Titan dune formation, in some cases giving us clues as to what larger scale evidence to look for in SAR images. Viewed at similar resolution, they provide interesting comparisons with the Titan dunes, both in likeness and differences. A part of this work was carried out at JPL under contract with NASA.

  2. Structure problems in the analog computation; Problemes de structure dans le calcul analogique

    Energy Technology Data Exchange (ETDEWEB)

    Braffort, P.L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The recent mathematical development showed the importance of elementary structures (algebraic, topological, etc.) in abeyance under the great domains of classical analysis. Such structures in analog computation are put in evidence and possible development of applied mathematics are discussed. It also studied the topological structures of the standard representation of analog schemes such as additional triangles, integrators, phase inverters and functions generators. The analog method gives only the function of the variable: time, as results of its computations. But the course of computation, for systems including reactive circuits, introduces order structures which are called 'chronological'. Finally, it showed that the approximation methods of ordinary numerical and digital computation present the same structure as these analog computation. The structure analysis permits fruitful comparisons between the several domains of applied mathematics and suggests new important domains of application for analog method. (M.P.)

  3. Analogies: Explanatory Tools in Web-Based Science Instruction

    Science.gov (United States)

    Glynn, Shawn M.; Taasoobshirazi, Gita; Fowler, Shawn

    2007-01-01

    This article helps designers of Web-based science instruction construct analogies that are as effective as those used in classrooms by exemplary science teachers. First, the authors explain what analogies are, how analogies foster learning, and what form analogies should take. Second, they discuss science teachers' use of analogies. Third, they…

  4. Analog to Digital Conversion in Physical Measurements

    CERN Document Server

    Kapitaniak, T; Feudel, U; Grebogi, C

    1999-01-01

    There exist measuring devices where an analog input is converted into a digital output. Such converters can have a nonlinear internal dynamics. We show how measurements with such converting devices can be understood using concepts from symbolic dynamics. Our approach is based on a nonlinear one-to-one mapping between the analog input and the digital output of the device. We analyze the Bernoulli shift and the tent map which are realized in specific analog/digital converters. Furthermore, we discuss the sources of errors that are inevitable in physical realizations of such systems and suggest methods for error reduction.

  5. A computational model of analogical reasoning

    Institute of Scientific and Technical Information of China (English)

    李波; 赵沁平

    1997-01-01

    A computational model of analogical reasoning is presented, which divides analogical reasoning process into four subprocesses, i.e. reminding, elaboration, matching and transfer. For each subprocess, its role and the principles it follows are given. The model is discussed in detail, including salient feature-based reminding, relevance-directed elaboration, an improved matching model and a transfer model. And the advantages of this model are summarized based on the results of BHARS, which is an analogical reasoning system implemented by this model.

  6. Analogies in science education: contributions and challenges

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Duarte

    2005-03-01

    Full Text Available An analogy is a comparison between domains of knowledge that have similarities at the levels of characteristics and relationships. Several authors highlight the importance of this tool in the teaching and learning of difficult scientific concepts. Nevertheless, some problems associated to the use of analogies have been found. This paper aims at contributing to a better understanding of the use of analogies in science education, by means of a review of the state of art regarding this matter. It will take into account its contribution to science education as well as the challenges to further research

  7. Comparison of various spring analogy related mesh deformation techniques in two-dimensional airfoil design optimization

    Science.gov (United States)

    Yang, Y.; Özgen, S.

    2017-06-01

    During the last few decades, CFD (Computational Fluid Dynamics) has developed greatly and has become a more reliable tool for the conceptual phase of aircraft design. This tool is generally combined with an optimization algorithm. In the optimization phase, the need for regenerating the computational mesh might become cumbersome, especially when the number of design parameters is high. For this reason, several mesh generation and deformation techniques have been developed in the past decades. One of the most widely used techniques is the Spring Analogy. There are numerous spring analogy related techniques reported in the literature: linear spring analogy, torsional spring analogy, semitorsional spring analogy, and ball vertex spring analogy. This paper gives the explanation of linear spring analogy method and angle inclusion in the spring analogy method. In the latter case, two di¨erent solution methods are proposed. The best feasible method will later be used for two-dimensional (2D) Airfoil Design Optimization with objective function being to minimize sectional drag for a required lift coe©cient at di¨erent speeds. Design variables used in the optimization include camber and thickness distribution of the airfoil. SU2 CFD is chosen as the §ow solver during the optimization procedure. The optimization is done by using Phoenix ModelCenter Optimization Tool.

  8. High quality digital holographic reconstruction on analog film

    Science.gov (United States)

    Nelsen, B.; Hartmann, P.

    2017-05-01

    High quality real-time digital holographic reconstruction, i.e. at 30 Hz frame rates, has been at the forefront of research and has been hailed as the holy grail of display systems. While these efforts have produced a fascinating array of computer algorithms and technology, many applications of reconstructing high quality digital holograms do not require such high frame rates. In fact, applications such as 3D holographic lithography even require a stationary mask. Typical devices used for digital hologram reconstruction are based on spatial-light-modulator technology and this technology is great for reconstructing arbitrary holograms on the fly; however, it lacks the high spatial resolution achievable by its analog counterpart, holographic film. Analog holographic film is therefore the method of choice for reconstructing highquality static holograms. The challenge lies in taking a static, high-quality digitally calculated hologram and effectively writing it to holographic film. We have developed a theoretical system based on a tunable phase plate, an intensity adjustable high-coherence laser and a slip-stick based piezo rotation stage to effectively produce a digitally calculated hologram on analog film. The configuration reproduces the individual components, both the amplitude and phase, of the hologram in the Fourier domain. These Fourier components are then individually written on the holographic film after interfering with a reference beam. The system is analogous to writing angularly multiplexed plane waves with individual component phase control.

  9. CMOS analog integrated circuit design technology; CMOS anarogu IC sekkei gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, H.; Fujisawa, A. [Fuji Electric Co. Ltd., Tokyo (Japan)

    2000-08-10

    In the field of the LSI (large scale integrated circuit) in rapid progress toward high integration and advanced functions, CAD (computer-aided design) technology has become indispensable to LSI development within a short period. Fuji Electric has developed design technologies and automatic design system to develop high-quality analog ICs (integrated circuits), including power supply ICs. within a short period. This paper describes CMOS (complementary metal-oxide semiconductor) analog macro cell, circuit simulation, automatic routing, and backannotation technologies. (author)

  10. Identifying Solar Analogs in the Kepler Field

    Science.gov (United States)

    Buzasi, Derek L.; Lezcano, Andrew; Preston, Heather L.

    2014-06-01

    Since human beings live on a planet orbiting a G2 V star, to us perhaps the most intrinsically interesting category of stars about which planets have been discovered is solar analogs. While Kepler has observed more than 26000 targets which have effective temperatures within 100K of the Sun, many of these are not true solar analogs due to activity, surface gravity, metallicity, or other considerations. Here we combine ground-based measurements of effective temperature and metallicity with data on rotational periods and surface gravities derived from 16 quarters of Kepler observations to produce a near-complete sample of solar analogs in the Kepler field. We then compare the statistical distribution of stellar physical parameters, including activity level, for subsets of solar analogs consisting of KOIs and those with no detected exoplanets. Finally, we produce a list of potential solar twins in the Kepler field.

  11. Use of analogy in learning scientific concepts.

    Science.gov (United States)

    Donnelly, C M; McDaniel, M A

    1993-07-01

    Four experiments compared learning of scientific concepts as expressed in either traditional literal form or through an analogy. Comprehension of basic-level details and inferential implications was measured through multiple-choice testing. In Experiment 1, literal or analogical renditions were presented in textual form only. In Experiment 2, text was accompanied by a dynamic video. In Experiment 3, the video and text literal rendition was compared with a text-only analogical rendition. In Experiment 4, subjects read only about a familiar domain. Subjects consistently answered basic-level questions most accurately when concepts were expressed literally, but answered inferential questions most accurately when concepts were expressed analogically. Analysis of individual differences (Experiment 2) indicated that this interaction strongly characterized the conceptual learning of science novices. The results are discussed within the framework of schema induction.

  12. Efficient Image Transmission Through Analog Error Correction

    CERN Document Server

    Liu, Yang; Li,; Xie, Kai

    2011-01-01

    This paper presents a new paradigm for image transmission through analog error correction codes. Conventional schemes rely on digitizing images through quantization (which inevitably causes significant bandwidth expansion) and transmitting binary bit-streams through digital error correction codes (which do not automatically differentiate the different levels of significance among the bits). To strike a better overall performance in terms of transmission efficiency and quality, we propose to use a single analog error correction code in lieu of digital quantization, digital code and digital modulation. The key is to get analog coding right. We show that this can be achieved by cleverly exploiting an elegant "butterfly" property of chaotic systems. Specifically, we demonstrate a tail-biting triple-branch baker's map code and its maximum-likelihood decoding algorithm. Simulations show that the proposed analog code can actually outperform digital turbo code, one of the best codes known to date. The results and fin...

  13. Synthesis and Biological Activity of Philanthotoxin Analogs

    Institute of Scientific and Technical Information of China (English)

    Yong An ZHANG; Ke Zhong LIU; Deng Yuan WANG; Yu Zhu WANG; Liang Jian QU; Chang Jin ZHU

    2006-01-01

    The synthesis of four analogs of philanthotoxin is described. The preliminary bioassay showed that these compounds all had good insecticidal activities, and the compound 6a had the best killing effect.

  14. The Structure of Analogical Models in Science.

    Science.gov (United States)

    1980-07-01

    analogies cannot. 8. A Freudian defense might claim that the theory merely reflects the illogic of the unconscious. But a theory about an unclarified...an initial comparison. To illustrate the points, analogies of historical importance are analyzed. Although the focus is on theory , some empirical...feature-list theory , the structure-mapping approach makes a strong distinction between objects and their attributes, on the one hand, and relationships, on

  15. Learning Domain Theories via Analogical Transfer

    Science.gov (United States)

    2007-01-01

    Shive & Weber 1982). In the linear kinematics section of the textbook used for this study ( Giancoli 1991), there are eight worked out examples...is analogous to the dynamics of linear motion” (p. 197, Giancoli 1991). This is common practice in textbooks, and analogies between domains form the...and Worked Solution All problems and worked solutions used in this work were taken from the same physics textbook ( Giancoli 1991). Problems are

  16. Synthetic heparin-binding growth factor analogs

    Science.gov (United States)

    Pena, Louis A.; Zamora, Paul; Lin, Xinhua; Glass, John D.

    2007-01-23

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain that binds a heparin-binding growth factor receptor, covalently bound to a hydrophobic linker, which is in turn covalently bound to a non-signaling peptide that includes a heparin-binding domain. The synthetic heparin-binding growth factor analogs are useful as soluble biologics or as surface coatings for medical devices.

  17. Analogy betwen dislocation creep and relativistic cosmology

    OpenAIRE

    J.A. Montemayor-Aldrete; J.D. Muñoz-Andrade; Mendoza-Allende, A.; Montemayor-Varela, A.

    2005-01-01

    A formal, physical analogy between plastic deformation, mainly dislocation creep, and Relativistic Cosmology is presented. The physical analogy between eight expressions for dislocation creep and Relativistic Cosmology have been obtained. By comparing the mathematical expressions and by using a physical analysis, two new equations have been obtained for dislocation creep. Also, four new expressions have been obtained for Relativistic Cosmology. From these four new equations, one may determine...

  18. Analog baseband circuits for sensor systems

    OpenAIRE

    2008-01-01

    This thesis is composed of six publications and an overview of the research topic, which also summarizes the work. The research presented in this thesis focuses on research into analog baseband circuits for sensor systems. The research is divided into three different topics: the integration of analog baseband circuits into a radio receiver for sensor applications; the integration of an ΔΣ modulator A/D converter into a GSM/WCDMA radio receiver for mobile phones, and the integration of algorit...

  19. Automated Integrated Analog Filter Design Issues

    OpenAIRE

    2015-01-01

    An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is t...

  20. The analogy between stereo depth and brightness.

    Science.gov (United States)

    Brookes, A; Stevens, K A

    1989-01-01

    Apparent depth in stereograms exhibits various simultaneous-contrast and induction effects analogous to those reported in the luminance domain. This behavior suggests that stereo depth, like brightness, is reconstructed, ie recovered from higher-order spatial derivatives or differences of the original signal. The extent to which depth is analogous to brightness is examined. There are similarities in terms of contrast effects but dissimilarities in terms of the lateral inhibition effects traditionally attributed to underlying spatial-differentiation operators.

  1. Protein Structure Prediction with Visuospatial Analogy

    Science.gov (United States)

    Davies, Jim; Glasgow, Janice; Kuo, Tony

    We show that visuospatial representations and reasoning techniques can be used as a similarity metric for analogical protein structure prediction. Our system retrieves pairs of α-helices based on contact map similarity, then transfers and adapts the structure information to an unknown helix pair, showing that similar protein contact maps predict similar 3D protein structure. The success of this method provides support for the notion that changing representations can enable similarity metrics in analogy.

  2. AMiBA Wideband Analog Correlator

    CERN Document Server

    Li, Chao-Te; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; Ho, P T P; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar; Lien, Chun-Hsien; Wang, Huei; Wei, Ray-Ming; Yang, Chia-Hsiang; Peterson, Jeffrey B; Chang, Su-Wei; Huang, Yau-De; Hwang, Yuh-Jing; Kesteven, Michael; Koch, Patrick; Liu, Guo-Chin; Nishioka, Hiroaki; Umetsu, Keiichi; Wei, Tashun; Wu, Jiun-Huei Proty

    2010-01-01

    A wideband analog correlator has been constructed for the Yuan-Tseh Lee Array for Microwave Background Anisotropy. Lag correlators using analog multipliers provide large bandwidth and moderate frequency resolution. Broadband IF distribution, backend signal processing and control are described. Operating conditions for optimum sensitivity and linearity are discussed. From observations, a large effective bandwidth of around 10 GHz has been shown to provide sufficient sensitivity for detecting cosmic microwave background variations.

  3. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum...... and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing....

  4. Nyquist AD Converters, Sensor Interfaces, and Robustness Advances in Analog Circuit Design, 2012

    CERN Document Server

    Baschirotto, Andrea; Steyaert, Michiel

    2013-01-01

    This book is based on the presentations during the 21st workshop on Advances in Analog Circuit Design.  Expert designers provide readers with information about a variety of topics at the frontier of analog circuit design, including Nyquist analog-to-digital converters, capacitive sensor interfaces, reliability, variability, and connectivity.  This book serves as a valuable reference to the state-of-the-art, for anyone involved in analog circuit research and development.  Provides a state-of-the-art reference in analog circuit design, written by experts from industry and academia; Presents material in a tutorial-based format; Includes coverage of Nyquist A/D converters, capacitive sensor interfaces, reliability, variability, and connectivity.

  5. Regulation of polyamine biosynthetic activity by spermidine and spermine analogs--a novel antiproliferative strategy.

    Science.gov (United States)

    Porter, C W; Bergeron, R J

    1988-01-01

    Interference with polyamine biosynthesis by analog-mediated regulatory mechanisms represents a viable alternative to the use of specific enzyme inhibitors as an antiproliferative strategy. The approach is unique among antimetabolite approaches and is made possible by unusual characteristics inherent to the polyamines and their biosynthetic pathway. Current antitumor data obtained with these analogs provides indication of their potential usefulness as antitumor agents but, at the same time, demonstrates the need for improvement. This latter might be attained by the rational design of analogs which (a) bind more tightly at enzyme regulatory sites, (b) which are less able to substitute for natural polyamines in growth related functions and (c) which are eliminated less rapidly from tumor-bearing animals. At the same time, the continued preclinical development of available analogs might proceed most productively by targeting large cell lung carcinoma and melanoma and by examining the generality of the relationship between oncogene expression and the accompanying sensitivity to regulatory analogs.

  6. Design of an Active Ultrastable Single-chain Insulin Analog

    Science.gov (United States)

    Hua, Qing-xin; Nakagawa, Satoe H.; Jia, Wenhua; Huang, Kun; Phillips, Nelson B.; Hu, Shi-quan; Weiss, Michael A.

    2008-01-01

    Single-chain insulin (SCI) analogs provide insight into the inter-relation of hormone structure, function, and dynamics. Although compatible with wild-type structure, short connecting segments (design, structure, and function of a single-chain insulin analog (SCI-57) containing a 6-residue linker (GGGPRR). Native receptor-binding affinity (130 ± 8% relative to the wild type) is achieved as hindrance by the linker is offset by favorable substitutions in the insulin moiety. The thermodynamic stability of SCI-57 is markedly increased (ΔΔGu = 0.7 ± 0.1 kcal/mol relative to the corresponding two-chain analog and 1.9 ± 0.1 kcal/mol relative to wild-type insulin). Analysis of inter-residue nuclear Overhauser effects demonstrates that a native-like fold is maintained in solution. Surprisingly, the glycine-rich connecting segment folds against the insulin moiety: its central Pro contacts ValA3 at the edge of the hydrophobic core, whereas the final Arg extends the A1-A8 α-helix. Comparison between SCI-57 and its parent two-chain analog reveals striking enhancement of multiple native-like nuclear Overhauser effects within the tethered protein. These contacts are consistent with wild-type crystal structures but are ordinarily attenuated in NMR spectra of two-chain analogs, presumably due to conformational fluctuations. Linker-specific damping of fluctuations provides evidence for the intrinsic flexibility of an insulin monomer. In addition to their biophysical interest, ultrastable SCIs may enhance the safety and efficacy of insulin replacement therapy in the developing world. PMID:18332129

  7. HERE, THERE, AND EVERYWHEREPublic Science Through Analogy

    Science.gov (United States)

    Arcand, Kimberly K.

    2014-06-01

    Here, There, and Everywhere (HTE) is a program that consists of a series of exhibitions, posters, and supporting hands-on activities that utilize analogies in the teaching of science, engineering, and technology to provide multi-generational and family-friendly content in English and Spanish to small community centers, libraries, under-resourced small science centers. The purpose of the program is to connect crosscutting science content (in Earth, atmospheric and planetary sciences and astrophysics) with everyday phenomena. By using different modes of content delivery, from physical exhibits and handouts,to interpretive stations, facilitated activities for educators, and online resources, HTE helps to demonstrate the universality of physical laws and the connection between our everyday world and the universe as a whole to members of the public who may not identify strongly with science. HTE is part of a series of public science projects created and developed by the Education and Public Outreach group at the Chandra X-ray Center. The authors discuss how HTE fits into the lineage of public science outreach that aims to engage the greater public in non-traditional venues for science learning and appreciation, as well as what might be learned about the participants of such projects.

  8. Cisplatin Analogs Confer Protection against Cyanide Poisoning.

    Science.gov (United States)

    Nath, Anjali K; Shi, Xu; Harrison, Devin L; Morningstar, Jordan E; Mahon, Sari; Chan, Adriano; Sips, Patrick; Lee, Jangwoen; MacRae, Calum A; Boss, Gerry R; Brenner, Matthew; Gerszten, Robert E; Peterson, Randall T

    2017-05-18

    Cisplatin holds an illustrious position in the history of chemistry most notably for its role in the virtual cure of testicular cancer. Here we describe a role for this small molecule in cyanide detoxification in vivo. Cyanide kills organisms as diverse as insects, fish, and humans within seconds to hours. Current antidotes exhibit limited efficacy and are not amenable to mass distribution requiring the development of new classes of antidotes. The binding affinity of the cyanide anion for the positively charged metal platinum is known to create an extremely stable complex in vitro. We therefore screened a panel of diverse cisplatin analogs and identified compounds that conferred protection from cyanide poisoning in zebrafish, mice, and rabbits. Cumulatively, this discovery pipeline begins to establish the characteristics of platinum ligands that influence their solubility, toxicity, and efficacy, and provides proof of concept that platinum-based complexes are effective antidotes for cyanide poisoning. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Numerical Simulation and Water Analog of Mold Filling Processes

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper demonstrates the potential of a computer code, developed by the authors, in shaping gating systems by modeling the fluid flow phenomena through a complex gating system during mold filling. A plate casting with dimension 200 mm×200 mm×50 mm was chosen as the verifying problem. Water analog studies were carried out on this casting. The comparison indicates that computer simulation could be a powerful tool in shaping gating systems.

  10. Analog IC Design at the University of Twente

    OpenAIRE

    2007-01-01

    This article describes some recent research results from the IC Design group of the University of Twente, located in Enschede, The Netherlands. Our research focuses on analog CMOS circuit design with emphasis on high frequency and broadband circuits. With the trend of system integration in mind, we try to develop new circuit techniques that enable the next steps in system integration in nanometer CMOS technology. Our research funding comes from industry, as well as from governmental organizat...

  11. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  12. Photoaffinity Labeling of Developing Jojoba Seed Microsomal Membranes with a Photoreactive Analog of Acyl-Coenzyme A (Acyl-CoA) (Identification of a Putative Acyl-CoA:Fatty Alcohol Acyltransferase.

    Science.gov (United States)

    Shockey, J. M.; Rajasekharan, R.; Kemp, J. D.

    1995-01-01

    Jojoba (Simmondsia chinensis, Link) is the only plant known that synthesizes liquid wax. The final step in liquid wax biosynthesis is catalyzed by an integral membrane enzyme, fatty acyl-coenzyme A (CoA):fatty alcohol acyltransferase, which transfers an acyl chain from acyl-CoA to a fatty alcohol to form the wax ester. To purify the acyltransferase, we have labeled the enzyme with a radioiodinated, photoreactive analog of acyl-CoA, 12-[N-(4-azidosalicyl)amino] dodecanoyl-CoA (ASD-CoA). This molecule acts as an inhibitor of acyltransferase activity in the dark and as an irreversible inhibitor upon exposure to ultraviolet light. Oleoyl-CoA protects enzymatic activity in a concentration-dependent manner. Photolysis of microsomal membranes with labeled ASD-CoA resulted in strong labeling of two polypeptides of 57 and 52 kD. Increasing concentrations of oleoyl-CoA reduced the labeling of the 57-kD polypeptide dramatically, whereas the labeling of the 52-kD polypeptide was much less responsive to oleoyl-CoA. Also, unlike the other polypeptide, the labeling of the 57-kD polypeptide was enhanced considerably when photolyzed in the presence of dodecanol. These results suggest that a 57-kD polypeptide from jojoba microsomes may be the acyl-CoA:fatty alcohol acyltransferase.

  13. The future of vitamin D analogs

    Directory of Open Access Journals (Sweden)

    Carlien eLeyssens

    2014-04-01

    Full Text Available The active form of vitamin D3, 1,25-dihydroxyvitamin D3, is a major regulator of bone and calcium homeostasis. In addition, this hormone also inhibits the proliferation and stimulates the differentiation of normal as well as malignant cells. Supraphysiological doses of 1,25-dihydroxyvitamin D3 are required to reduce cancer cell proliferation. However, these doses will lead in vivo to calcemic side effects such as hypercalcemia and hypercalciuria. During the last 25 years, many structural analogs of 1,25-dihydroxyvitamin D3 have been synthesized by the introduction of chemical modifications in the A-ring, central CD-ring region or side chain of 1,25-dihydroxyvitamin D3 in the hope to find molecules with a clear dissociation between the beneficial antiproliferative effects and adverse calcemic side effects. One example of such an analog with a good dissociation ratio is calcipotriol (DaivonexR, which is clinically used to treat the hyperproliferative skin disease psoriasis. Other vitamin D analogs were clinically approved for the treatment of osteoporosis or secondary hyperparathyroidism. No vitamin D analog is currently used in the clinic for the treatment of cancer although several analogs have been shown to be potent drugs in animal models of cancer. Omics studies as well as in vitro cell biological experiments unraveled basic mechanisms involved in the antineoplastic effects of vitamin D and its analogs. 1,25-dihydroxyvitamin D3 and analogs act in a cell type- and tissue-specific manner. Moreover, a blockade in the transition of the G0/1 towards S phase of the cell cycle, induction of apoptosis, inhibition of migration and invasion of tumor cells together with effects on angiogenesis and inflammation have been implicated in the pleiotropic effects of 1,25-dihydroxyvitamin D3 and its analogs. In this review we will give an overview of the action of vitamin D analogs in tumor cells and look forward how these compounds could be introduced in the

  14. Structure-activity relationship studies on natural and synthetic bile acid analogs.

    Science.gov (United States)

    Roda, A; Grigolo, B; Pellicciari, R; Natalini, B

    1989-12-01

    The objective of our research was to develop ursodiol analogs that are structurally modified to modulate hepatic side-chain amidation and prevent 7-dehydroxylation by intestinal bacteria while at the same time maintaining the critical micellar concentration (CMC) and hydrophilicity of ursodiol. More than 20 naturally occurring bile acids were screened for physicochemical properties. Then, two generations of analogs were studied, and those with physicochemical properties similar to ursodiol's were analyzed for physiologic properties. The first generation of analogs included molecules with steric and/or electronic hindrance on the side chain; the second group consisted of the same molecules conjugated with glycine or taurine and also "pseudoconjugated" analogs (23-hydroxylated, esterified, and amidated with other amino acids). Of the first-generation analogs, only cyclopropane D derivative and trans-olefin were useful to our purposes, being conjugated by the liver and almost completely recovered in bile. These two analogs were deconjugated and 7-dehydroxylated but with slower kinetics. The hydrophilicity of the molecules could be augmented by increasing the polarity of the steroid ring. Among the pseudoconjugated analogs, the CMC values were similar to those of the natural analogs, although hydrophobicity differed among the group. The analogs that were not deconjugated were not 7-dehydroxylated either. All of the pseudoconjugated bile acids were efficiently taken up by the liver, and their recovery in bile was similar to that of glycine and taurine ursodiol. From these studies we now know that side chain configuration and conformation are important in the conjugation and deconjugation processes. Mild modification of the side chain can prevent 7-dehydroxylation and thus yield a bile acid more resistant to intestinal bacteria and more bioavailable. Prevention of hepatic conjugation improves biliary secretion and recovery of many analogs.

  15. Magnetic activity of seismic solar analogs

    CERN Document Server

    Salabert, D

    2016-01-01

    We present our latest results on the solar-stellar connection by studying 18 solar analogs that we identified among the Kepler seismic sample (Salabert et al., 2016a). We measured their magnetic activity properties using observations collected by the Kepler satellite and the ground-based, high-resolution Hermes spectrograph. The photospheric (Sph) and chromospheric (S) magnetic activity proxies of these seismic solar analogs are compared in relation to solar activity. We show that the activity of the Sun is actually comparable to the activity of the seismic solar analogs. Furthermore, we report on the discovery of temporal variability in the acoustic frequencies of the young (1 Gyr-old) solar analog KIC10644253 with a modulation of about 1.5 years, which agrees with the derived photospheric activity (Salabert et al., 2016b). It could actually be the signature of the short-period modulation, or quasi-biennal oscillation, of its magnetic activity as observed in the Sun and the 1-Gyr-old solar analog HD30495. In...

  16. A Multi-Gigahertz Analog Transient Recorder Integrated Circuit

    CERN Document Server

    Kleinfelder, Stuart A

    2015-01-01

    A monolithic multi-channel analog transient recorder, implemented using switched capacitor sample-and-hold circuits and a high-speed analogically-adjustable delay-line-based write clock, has been designed, fabricated and tested. The 2.1 by 6.9 mm layout, in 1.2 micron CMOS, includes over 31,000 transistors and 2048 double polysilicon capacitors. The circuit contains four parallel channels, each with a 512 deep switched-capacitor sample-and-hold system. A 512 deep edge sensitive tapped active delay line uses look-ahead and 16 way interleaving to develop the 512 sample and hold clocks, each as little as 3.2 ns wide and 200 ps apart. Measurements of the device have demonstrated 5 GHz maximum sample rate, at least 350 MHz bandwidth, an extrapolated rms aperture uncertainty per sample of 0.7 ps, and a signal to rms noise ratio of 2000:1.

  17. Memristor-MOS analog correlator for pattern recognition system.

    Science.gov (United States)

    Han, Ca-Ram; Lee, Sang-Jin; Oh, Kwang-Seok; Cho, Kyoungrok

    2013-05-01

    Emergence of new materials having significant improved properties continues to influence the formulation of novel architectures and as such new developments pave the way for innovative circuits and systems such as those required in visual imaging and recognition systems. In this paper we introduce a novel approach for the design of an analog comparator suitable for pattern matching using two Memristors as part of both the stored image data as well as that of the input signal. Our proposed comparator based on Memristor-CMOS fabrication process generates a signal indicating similarity/dissimilarity between two pattern data derived from image sensor and the corresponding Memristor-based template memory. For convenience, we also present an overview of a simplified Memristor model and hence provide simulation results for comparison with that of a conventional analog CMOS comparator.

  18. A 12-channel analog optical-receiver module

    CERN Document Server

    Vasey, F; Sugiyama, M; Troska, J

    2005-01-01

    A 12-channel analog optical-receiver module has been developed for the compact muon solenoid (CMS) experiment to be installed at the European Organization for Nuclear Research (CERN) large hadron collider (LHC). It is based on a modified commercial 12-channel module, where the digital amplifier application-specified integrated circuit (ASIC) has been replaced by a custom-designed analog variant. The module features an 8-bit dynamic range with 1% integral-linearity deviation in a 100-MHz bandwidth. A user-configurable input capacitor-matching network allows for the control of the overshoot of the received pulse-amplitude-modulated signal. The ASIC-receiver- circuit implementation as well as the module design and manufacture are reviewed. Results of the successful functional performance evaluation of the module are shown.

  19. Synthesis and evaluation of indazole based analog sensitive Akt inhibitors.

    Science.gov (United States)

    Okuzumi, Tatsuya; Ducker, Gregory S; Zhang, Chao; Aizenstein, Brian; Hoffman, Randy; Shokat, Kevan M

    2010-08-01

    The kinase Akt is a key signaling node in regulating cellular growth and survival. It is implicated in cancer by mutation and its role in the downstream transmission of aberrant PI3K signaling. For these reasons, Akt has become an increasingly important target of drug development efforts and several inhibitors are now reaching clinical trials. Paradoxically it has been observed that active site kinase inhibitors of Akt lead to hyperphosphorylation of Akt itself. To investigate this phenomenon we here describe the application of a chemical genetics strategy that replaces native Akt with a mutant version containing an active site substitution that allows for the binding of an engineered inhibitor. This analog sensitive strategy allows for the selective inhibition of a single kinase. In order to create the inhibitor selective for the analog sensitive kinase, a diversity of synthetic approaches was required, finally resulting in the compound PrINZ, a 7-substituted version of the Abbott Labs Akt inhibitor A-443654.

  20. Moon and Mars Analog Mission Activities for Mauna Kea 2012

    Science.gov (United States)

    Graham, Lee D.; Morris, Richard V.; Graff, Trevor G.; Yingst, R. Aileen; tenKate, I. L.; Glavin, Daniel P.; Hedlund, Magnus; Malespin, Charles A.; Mumm, Erik

    2012-01-01

    Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were recently completed at Mauna Kea, Hawaii. Scientific investigations, scientific input, and science operations constraints were tested in the context of an existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration. Initial science operations were planned based on a model similar to the operations control of the Mars Exploration Rovers (MER). However, evolution of the operations process occurred as the analog mission progressed. We report here on the preliminary sensor data results, an applicable methodology for developing an optimum science input based on productive engineering and science trades discussions and the science operations approach for an investigation into the valley on the upper slopes of Mauna Kea identified as "Apollo Valley".

  1. Analog Front-End Electronics in Beam Instrumentation

    CERN Document Server

    Boscolo, A

    2005-01-01

    The work gives an overview of present and near future technological opportunities for the first analog conditioning and subsequent signal processing of sensor signal. The interactions between beam sensor capability, their signals characteristics and the system requirements are analyzed from different approaches as: full analog continuous, sampled time discrete, full digital time and amplitude discrete. Special attention will be given to the impact of measurement methods and new devices in circuits and instrumentation architecture design, especially from the metrological point of view. A lot of measurement methods and related systems have been developed in order to overcome technological drawbacks and to reach the best cost-performances ratio. By a system revamping, some of these still now show the capability of reaching the actual technological limits in a simpler way in many applications as: ADC, linear and non linear signal processing, ultra high speed logic, etc. These methods could be carried out by the n...

  2. Analog Ensemble Methodology: Expansion and Optimization for Renewable Energy Applications

    Science.gov (United States)

    Harding, L.; Cervone, G.; Delle Monache, L.

    2015-12-01

    Renewable energy is fundamental for sustaining and developing society. Solar and wind energy are promising sources because of their decreased environmental impact relative to conventional energy sources, improved efficiency, and increased use. A key challenge with renewable energy production is the generation of accurate renewable energy forecasts at varying spatial and temporal scales to assist utility companies in effective energy management. Specifically, this research applies the Analog Ensemble (AnEn) methodology to short-term (0-48 hour) wind speed forecasting for power generation and short-term (0-72) hour solar power measured (PM) output predictions. AnEn uses a set of past observations corresponding to the best analogs of a deterministic numerical weather prediction model to generate a probability distribution of future atmospheric states: an ensemble of analogs. Currently the AnEn methodology equally weights predictors and only handles 1D(time). We determine an optimal distribution of predictor weights based upon parameter characteristics, investigate spatial variations in the application of the methodology and develop a theory expanding the methodology into 2D. The AnEn methodology improves short-term prediction accuracy, decreases computational costs and provides uncertainty quantification allowing utility companies to manage over- or under power generation for renewable energy sources.

  3. Analog Design for Digital Deployment of a Serious Leadership Game

    Science.gov (United States)

    Maxwell, Nicholas; Lang, Tristan; Herman, Jeffrey L.; Phares, Richard

    2012-01-01

    This paper presents the design, development, and user testing of a leadership development simulation. The authors share lessons learned from using a design process for a board game to allow for quick and inexpensive revision cycles during the development of a serious leadership development game. The goal of this leadership simulation is to accelerate the development of leadership capacity in high-potential mid-level managers (GS-15 level) in a federal government agency. Simulation design included a mixed-method needs analysis, using both quantitative and qualitative approaches to determine organizational leadership needs. Eight design iterations were conducted, including three user testing phases. Three re-design iterations followed initial development, enabling game testing as part of comprehensive instructional events. Subsequent design, development and testing processes targeted digital application to a computer- and tablet-based environment. Recommendations include pros and cons of development and learner testing of an initial analog simulation prior to full digital simulation development.

  4. Not All Analogies Are Created Equal: Associative and Categorical Analogy Processing following Brain Damage

    Science.gov (United States)

    Schmidt, Gwenda L.; Cardillo, Eileen R.; Kranjec, Alexander; Lehet, Matthew; Widick, Page; Chatterjee, Anjan

    2012-01-01

    Current research on analogy processing assumes that different conceptual relations are treated similarly. However, just as words and concepts are related in distinct ways, different kinds of analogies may employ distinct types of relationships. An important distinction in how words are related is the difference between associative (dog-bone) and…

  5. Not All Analogies Are Created Equal: Associative and Categorical Analogy Processing following Brain Damage

    Science.gov (United States)

    Schmidt, Gwenda L.; Cardillo, Eileen R.; Kranjec, Alexander; Lehet, Matthew; Widick, Page; Chatterjee, Anjan

    2012-01-01

    Current research on analogy processing assumes that different conceptual relations are treated similarly. However, just as words and concepts are related in distinct ways, different kinds of analogies may employ distinct types of relationships. An important distinction in how words are related is the difference between associative (dog-bone) and…

  6. Discursive interactions and the use of analogies in physics teaching

    Directory of Open Access Journals (Sweden)

    Fernanda Cátia Bozelli

    2012-03-01

    Full Text Available In the last few years, Science Education researchers have shown new ways do conceive the processes of teaching and learning, demanding the displacement from the individual understanding of specific phenomena to a new context, which means, to a bias of meanings construction in a social context. However, still there are few researches concerned with how teachers give support to the process throughout the students build meanings in science classrooms, about how these interactions are produced, developed and, in what level they indeed interfere in students’ learning. This research tries to move forward in this line of research, investigating the interactive discursive processes related to the figures of speech (in this case, analogies, particularly about the context of its creation, working out and exploration in physics classrooms. One of the questions which allowed that reflection was that to explain scientific concepts in classroom involves, even to understand contents, as to be able to communicate this content in a more effective way. Does the posture assumed by teachers in the conversational aspect, during the discursive interaction, has contributed or influenced the rise and exploration of analogies in classrooms? To answer these questions we adopted a qualitative and interpretative approach, trough which we analyzed a sample of 23 futures high school physics teachers, during a semester, when the development of supervised practicum activities, carried out in the two last semesters of their undergraduate program, done in a public state university in São Paulo, Brazil. Data collected show that it is necessary more discussion about the use of analogies in teachers initial training programs; taking account its function, benefit or disadvantage, how to explore analogies in a more effective way. Besides that, how the discursive interactive context among teacher and students can interfere in the teaching and learning processes in classroom. We

  7. Analogy-Enhanced Instruction: Effects on Reasoning Skills in Science

    Science.gov (United States)

    Remigio, Krisette B.; Yangco, Rosanelia T.; Espinosa, Allen A.

    2014-01-01

    The study examined the reasoning skills of first year high school students after learning general science concepts through analogies. Two intact heterogeneous sections were randomly assigned to Analogy-Enhanced Instruction (AEI) group and Non Analogy-Enhanced (NAEI) group. Various analogies were incorporated in the lessons of the AEI group for…

  8. Value and Limitations of Analogs in Teaching Mathematics.

    Science.gov (United States)

    Halford, Graeme S.; Boulton-Lewis, Gillian M.

    Analogical reasoning is frequently used in acquisition of mathematical concepts. Concrete representations used to teach mathematics are essentially analogs of mathematical concepts, and it is argued that analogies enter into mathematical concept acquisition in numerous other ways as well. According to Gentner's theory, analogies entail a…

  9. Analog Module Placement Design Using Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper presents a novel genetic algorithm for analog module placement based on ageneralization of the two-dimensional bin packing problem. The genetic encoding and operators assure that allproblem constraints are always satisfied. Thus the potential problems of adding penalty terms to the costfunction are eliminated so that the search configuration space is drastically decreased. The dedicated costfunction is based on the special requirements of analog integrated circuits. A fractional factorial experimentwas conducted using an orthogonal array to study the algorithm parameters. A meta GA was applied todetermine the optimal parameter values. The algorithm was tested with several local benchmark circuits. Theexperimental results show that the algorithm has better performance than the simulated annealing approachwith satisfactory results comparable to manual placement. This study demonstrates the effectiveness of thegenetic algorithm in the analog module placement problem. The algorithm has been successfully used in alayout synthesis tool.

  10. Chemical synthesis of dinucleotide cap analogs.

    Science.gov (United States)

    Kore, Anilkumar R; Shanmugasundaram, Muthian

    2014-12-19

    This unit describes a reliable, efficient and general method for the synthesis of standard cap analog (mCAP), m(7)G[5']ppp[5']G, and anti-reverse cap analog (ARCA), m(7,3')(O)G[5']ppp[5']G. The synthesis of required intermediate m(7)GDP or m(2)(7,3'O)GDP has been achieved through regioselective methylation of the corresponding diphosphate using dimethyl sulfate under aqueous conditions. Then, the coupling reaction of m(7)GDP or m(2)(7,3'O)GDP with ImGMP using ZnCl(2)/DMF system affords the corresponding cap analog in good yields. Copyright © 2014 John Wiley & Sons, Inc.

  11. On Lovelock analogs of the Riemann tensor

    Energy Technology Data Exchange (ETDEWEB)

    Camanho, Xian O. [Albert-Einstein-Institut, Max-Planck-Institut fuer Gravitationsphysik, Golm (Germany); Dadhich, Naresh [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); Inter-University Centre for Astronomy and Astrophysics, Pune (India)

    2016-03-15

    It is possible to define an analog of the Riemann tensor for Nth order Lovelock gravity, its characterizing property being that the trace of its Bianchi derivative yields the corresponding analog of the Einstein tensor. Interestingly there exist two parallel but distinct such analogs and the main purpose of this note is to reconcile both formulations. In addition we will introduce a simple tensor identity and use it to show that any pure Lovelock vacuum in odd d = 2N + 1 dimensions is Lovelock flat, i.e. any vacuum solution of the theory has vanishing Lovelock-Riemann tensor. Further, in the presence of cosmological constant it is the Lovelock-Weyl tensor that vanishes. (orig.)

  12. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  13. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters

    DEFF Research Database (Denmark)

    Sezgin, Erdinc; Betul Can, Fatma; Schneider, Falk

    2016-01-01

    Cholesterol is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of cholesterol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently......-labeled cholesterol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction and trafficking in cells, hence it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs...

  14. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters

    DEFF Research Database (Denmark)

    Sezgin, Erdinc; Betul Can, Fatma; Schneider, Falk

    2016-01-01

    cholesterol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction and trafficking in cells, hence it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs......Cholesterol is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of cholesterol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently-labeled...

  15. Associative Pattern Recognition In Analog VLSI Circuits

    Science.gov (United States)

    Tawel, Raoul

    1995-01-01

    Winner-take-all circuit selects best-match stored pattern. Prototype cascadable very-large-scale integrated (VLSI) circuit chips built and tested to demonstrate concept of electronic associative pattern recognition. Based on low-power, sub-threshold analog complementary oxide/semiconductor (CMOS) VLSI circuitry, each chip can store 128 sets (vectors) of 16 analog values (vector components), vectors representing known patterns as diverse as spectra, histograms, graphs, or brightnesses of pixels in images. Chips exploit parallel nature of vector quantization architecture to implement highly parallel processing in relatively simple computational cells. Through collective action, cells classify input pattern in fraction of microsecond while consuming power of few microwatts.

  16. Analogies between a Meniscus and a Cantilever

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Lin

    2009-01-01

    Systematic and quantitative analyses of exact analogies between a meniscus and an elastica are performed. It is shown that the two governing equations take the same style after coordinate translation and scale transformation. The morphologies of the liquid bridge and the cantilever are calculated in terms of elliptic integrations, which can be reduced to the same shape,after converting the boundary conditions. The present analyses can make us grasp the nature of this physical phenomenon deeply and show some inspiration for designing the analogy experiments. Moreover, the calculated results are helpful to engineering applications, such as design and fabrication of MEMS, and micro-manipulations in micro/nano- technology.

  17. Discrete analog computing with rotor-routers.

    Science.gov (United States)

    Propp, James

    2010-09-01

    Rotor-routing is a procedure for routing tokens through a network that can implement certain kinds of computation. These computations are inherently asynchronous (the order in which tokens are routed makes no difference) and distributed (information is spread throughout the system). It is also possible to efficiently check that a computation has been carried out correctly in less time than the computation itself required, provided one has a certificate that can itself be computed by the rotor-router network. Rotor-router networks can be viewed as both discrete analogs of continuous linear systems and deterministic analogs of stochastic processes.

  18. Synthetic heparin-binding factor analogs

    Science.gov (United States)

    Pena, Louis A.; Zamora, Paul O.; Lin, Xinhua; Glass, John D.

    2010-04-20

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain, and preferably two peptide chains branched from a dipeptide branch moiety composed of two trifunctional amino acid residues, which peptide chain or chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a linker, which may be a hydrophobic linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  19. Landauer Bound for Analog Computing Systems

    CERN Document Server

    Diamantini, M Cristina; Trugenberger, Carlo A

    2016-01-01

    By establishing a relation between information erasure and continuous phase transitions we generalise the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  20. Transparent Analogs for Alloy Phase Studies

    Science.gov (United States)

    Frazier, D. O.; Smith, James E., Jr.

    1987-01-01

    Report describes experiments to add information to data base supporting use of transparent, partially miscible liquids and solids as analogs in studies of alloy solidification. Behavior of these materials observed directly while they undergo liquid/liquid and liquid/solid phase transformations. Light-scattering techniques used to determine phase boundaries. Transparent analogs allow observation of both solidification patterns and processes leading to those patterns, whereas metal alloys require tedious post-solidification metallographic analyses because processes not generally observed. Experiments with transparent substances safer and cheaper since conducted at much lower temperatures.

  1. Automated Integrated Analog Filter Design Issues

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2015-07-01

    Full Text Available An analysis of modern automated integrated analog circuits design methods and their use in integrated filter design is done. Current modern analog circuits automated tools are based on optimization algorithms and/or new circuit generation methods. Most automated integrated filter design methods are only suited to gmC and switched current filter topologies. Here, an algorithm for an active RC integrated filter design is proposed, that can be used in automated filter designs. The algorithm is tested by designing an integrated active RC filter in a 65 nm CMOS technology.

  2. An Optical Analog of a Black Holes

    CERN Document Server

    Royston, A; Royston, Andrew; Gass, Richard

    2002-01-01

    Using media with extremely low group velocities one can create an optical analog of a curved space-time. Leonhardt and Piwnicki have proposed that a vortex flow will act as an optical black hole. We show that although the Leonhardt - Piwnicki flow has an orbit of no return and an infinite red-shift surface, it is not a true black hole since it lacks a null hypersurface. However a radial flow will produce a true optical black hole that has a Hawking temperature and obeys the first law of black hole mechanics. By combining the Leonhardt - Piwnicki flow with a radial flow we obtain the analog of the Kerr black hole.

  3. Fungitoxicity of chemical analogs with heartwood toxins.

    Science.gov (United States)

    Grohs, B M; Kunz, B

    1998-07-01

    Trans-stilbene and tropolone as chemical analogs with naturally occurring fungitoxic heartwood compounds were studied with respect to their fungitoxic potency. While stilbene showed no fungitoxic activity towards the fungi Aureobasidium pullulans var. melanogenum, Penicillium glabrum, and Trichoderma harzianum in the concentrations tested, the minimal inhibiting concentration of tropolone was 10(-3) M for Penicillium glabrum and Trichoderma harzianum, and 10(-5) M for Aureobasidium pullulans var. melanogenum. In all cases, the effect of tropolone was a fungistatic one. Using chemical analogs for assessing the chemical basis of the fungitoxicity of tropolone, this substance proved to be the only compound tested which possesses fungitoxic properties.

  4. Words, Concepts, and the Geometry of Analogy

    Directory of Open Access Journals (Sweden)

    Stephen McGregor

    2016-08-01

    Full Text Available This paper presents a geometric approach to the problem of modelling the relationship between words and concepts, focusing in particular on analogical phenomena in language and cognition. Grounded in recent theories regarding geometric conceptual spaces, we begin with an analysis of existing static distributional semantic models and move on to an exploration of a dynamic approach to using high dimensional spaces of word meaning to project subspaces where analogies can potentially be solved in an online, contextualised way. The crucial element of this analysis is the positioning of statistics in a geometric environment replete with opportunities for interpretation.

  5. ENHANCING THE SYMBOLIC ANALYSIS OF ANALOG CIRCUITS

    Directory of Open Access Journals (Sweden)

    E. Tlelo-Cuautle

    2005-08-01

    Full Text Available A new symbollc-method is introduced to enhance the calculation of symbolic expressions of analog circults. First, the analog circuit is transformed to a nullor equivalent circuit. Second, a new method is introduced to the formulation of a compact system of equations (CSES. Third, a new method is introduced to the solution of theCSES, by avoiding multiplications by zero to Improve the evaluation of determlnants. Flnally, two eXamples are given to show the usefulness of the proposed methods to calculate fully symbolic transfer functions.

  6. Analog circuit design for communication SOC

    CERN Document Server

    Tu, Steve Hung-Lung

    2012-01-01

    This e-book provides several state-of-the-art analog circuit design techniques. It presents both empirical and theoretical materials for system-on-a-chip (SOC) circuit design. Fundamental communication concepts are used to explain a variety of topics including data conversion (ADC, DAC, S-? oversampling data converters), clock data recovery, phase-locked loops for system timing synthesis, supply voltage regulation, power amplifier design, and mixer design. This is an excellent reference book for both circuit designers and researchers who are interested in the field of design of analog communic

  7. Landauer bound for analog computing systems

    Science.gov (United States)

    Diamantini, M. Cristina; Gammaitoni, Luca; Trugenberger, Carlo A.

    2016-07-01

    By establishing a relation between information erasure and continuous phase transitions we generalize the Landauer bound to analog computing systems. The entropy production per degree of freedom during erasure of an analog variable (reset to standard value) is given by the logarithm of the configurational volume measured in units of its minimal quantum. As a consequence, every computation has to be carried on with a finite number of bits and infinite precision is forbidden by the fundamental laws of physics, since it would require an infinite amount of energy.

  8. 电流模式可重构模拟信号处理电路%Current-Mode Reconfigurable Analog Circuit for Analog Signal Processing

    Institute of Scientific and Technical Information of China (English)

    王友仁; 祝鸣涛; 崔江; 林华; 姜媛媛

    2011-01-01

    There are problems of limited function, low operational speed and insufficient flexibility in the conventional reconfigurable analog circuits. A new current-mode reconfigurable analog circuit is proposed to solve them. The configurable analog block (CAB) based on second-generation current controlled conveyor (CCCII) is designed, which has the advantages of smaller nonlinear distortion, higher operational speed and better anti-interference ability. A new crossbar switch inter-connection network is developed, which can reduce the number of switches, and improve the flexibility and high frequency response of the reconfigurable analog circuit. The forth-order butterworth low-pass filter (LPF) and the analog multiplier are reconfigured with 2X4 reconfigurable analog circuit array. The experimental results show that the proposed reconfigurable analog circuit can effectively realize analog signal processing circuits of different functions through reconfiguration.%针对现有的可重构模拟电路存在功能有限、带宽小、灵活性不足等同题,设计了一种新的电流模式可重构模拟电路.设计了基于二代电流传输控制器的可重构模拟单元,能减小电路非线性失真,提高电路工作速度与抗干扰能力.设计了一种可编程开关数量较少的纵横交叉开关网络结构,提高了电路灵活性和高频性能.在2×4一阵列结构上分别重构实现了四阶低通滤波器和模拟乘法器,实验结果表明所设计可重构模拟电路是有效的.

  9. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog filte

  10. High-speed and high-resolution analog-to-digital and digital-to-analog converters

    NARCIS (Netherlands)

    van de Plassche, R.J.

    1989-01-01

    Analog-to-digital and digital-to-analog converters are important building blocks connecting the analog world of transducers with the digital world of computing, signal processing and data acquisition systems. In chapter two the converter as part of a system is described. Requirements of analog

  11. Prediction of in vitro metabolic stability of calcitriol analogs by QSAR

    Science.gov (United States)

    Jensen, Berith F.; Sørensen, Morten D.; Kissmeyer, Anne-Marie; Björkling, Fredrik; Sonne, Kim; Engelsen, Søren B.; Nørgaard, Lars

    2003-12-01

    The metabolic stability of a drug is an important property for potential drug candidates. Measuring this property, however, can be costly and time-consuming. The use of quantitative structure-activity relationships (QSAR) to estimate the in vitro stability is an attractive alternative to experimental measurements. A data set of 130 calcitriol analogs with known values of in vitro metabolic stability was used to develop QSAR models. The analogs were encoded with molecular structure descriptors computed mainly with the commercial software QikProp and DiverseSolutions. Variable selection was carried out by five different variable selection techniques and Partial Least Squares Regression (PLS) models were generated from the 130 analogs. The models were used for prediction of the metabolic stability of 244 virtual calcitriol analogs. Twenty of the 244 analogs were selected and the in vitro metabolic stability was determined experimentally. The PLS models were able to predict the correct metabolic stability for 17 of the 20 selected analogs, corresponding to a prediction performance of 85%. The results clearly demonstrate the utility of QSAR models in predicting the in vitro metabolic stability of calcitriol analogs.

  12. The molecular mechanism of thalidomide analogs in hematologic malignancies.

    Science.gov (United States)

    Lindner, Stefanie; Krönke, Jan

    2016-12-01

    Thalidomide was sold in the 1950s as a sedative and was also used by pregnant women to treat morning sickness. It became notorious for causing severe birth defects and was removed from the market. More than four decades later, thalidomide had a renaissance in the treatment of cancer. Thalidomide and its more potent analogs, lenalidomide and pomalidomide, are nowadays approved treatments for multiple myeloma and myelodysplastic syndrome with deletion of chromosome 5q. In addition, thalidomide and its analogs inhibit release of tumor necrosis factor-α and increase interleukin-2 (IL-2) and interferon-γ release from T cells. The underlying molecular mechanisms for these pleiotropic effects remained obscure until the identification of the cereblon (CRBN) E3 ubiquitin ligase as the primary target of thalidomide and its analogs in 2010. Binding of thalidomide or lenalidomide increases the affinity of CRBN to the transcription factors IKZF1 and IKZF3 and casein kinase 1α (CK1α). Ubiquitination and degradation of these neo-substrates results in IL-2 release and growth arrest of multiple myeloma and MDS cells. The discovery of this previously undescribed mechanism for an approved drug provides a proof-of-concept for the development of new therapeutics that exploit ubiquitin ligases for specific degradation of disease-associated proteins.

  13. Mathematical analogies in physics. Thin-layer wave theory

    Directory of Open Access Journals (Sweden)

    José M. Carcione

    2014-03-01

    Full Text Available Field theory applies to elastodynamics, electromagnetism, quantum mechanics, gravitation and other similar fields of physics, where the basic equations describing the phenomenon are based on constitutive relations and balance equations. For instance, in elastodynamics, these are the stress-strain relations and the equations of momentum conservation (Euler-Newton law. In these cases, the same mathematical theory can be used, by establishing appropriate mathematical equivalences (or analogies between material properties and field variables. For instance, the wave equation and the related mathematical developments can be used to describe anelastic and electromagnetic wave propagation, and are extensively used in quantum mechanics. In this work, we obtain the mathematical analogy for the reflection/refraction (transmission problem of a thin layer embedded between dissimilar media, considering the presence of anisotropy and attenuation/viscosity in the viscoelastic case, conductivity in the electromagnetic case and a potential barrier in quantum physics (the tunnel effect. The analogy is mainly illustrated with geophysical examples of propagation of S (shear, P (compressional, TM (transverse-magnetic and TE (transverse-electric waves. The tunnel effect is obtained as a special case of viscoelastic waves at normal incidence.

  14. Analog Signal Processing Approach for Coarse and Fine Depth Estimation

    Directory of Open Access Journals (Sweden)

    Nihar Athreyas

    2014-12-01

    Full Text Available Imaging and Image sensors is a field that is continuously evolving. There are new products coming into the market every day. Some of these have very severe Size, Weight and Power constraints whereas other devices have to handle very high computational loads. Some require both these conditions to be met simultaneously. Current imaging architectures and digital image processing solutions will not be able to meet these ever increasing demands. There is a need to develop novel imaging architectures and image processing solutions to address these requirements. In this work we propose analog signal processing as a solution to this problem. The analog processor is not suggested as a replacement to a digital processor but it will be used as an augmentation device which works in parallel with the digital processor, making the system faster and more efficient. In order to show the merits of analog processing two stereo correspondence algorithms are implemented. We propose novel modifications to the algorithms and new imaging architectures which, significantly reduces the computation time

  15. On an Analog Controlled Precision Heat Power Source

    Science.gov (United States)

    Seilmayer, M.; Katepally, V. K.

    2017-07-01

    The analog controlled precision heat power source is the main part of a sensor development to estimate real time properties of the primary coolant in a 300 kW process cooling system. The measurement of physical properties like thermal conductivity or thermal diffusion requires a precise and accurate heater. The constant heat flux is then applied to the liquid under test to acquire its different properties. Here, commonly established control methods of heating with constant current or constant voltage may fail because the heating resistor changes its resistance with temperature. The idea is to utilize a power monitor circuit like the LT2940, which contains an analog multiplier with a control loop around it. The initial design and its assumed uncertainties will be discussed. The first version of the power controller shows an outstanding performance in terms of precision in a steady state. Compared to conventional switching mode power sources the approach with an analog controlled heater avoids EMI issues as well. The main goal of the present design is a precise source of heat power with less than 0.5% of error.

  16. Wavelength-agile integrated optical transmitters for analog applications

    Science.gov (United States)

    Johansson, Leif A.; Chen, Chin-Hui; Akulova, Yuliya A.; Fish, Gregory A.; Coldren, Larry A.

    2003-12-01

    A summary of current work involving the development of high performance, wavelength-tunable integrated optical transmitters for analog applications is given. The performance of sampled-grating DBR lasers integrated with an SOA and an electroabsorption or Mach-Zehnder modulator is evaluated in terms of E/O conversion efficiency, noise performance and dynamic range. Optimization options to maximize either gain, noise figure or spurious-free dynamic range in analog link applications are discussed. It is shown how the combination of chip-scale integration and the use of bulk waveguide Franz-Keldysh absorption allows coupling of a large optical power level into the electroabsorption modulator, and its effects on the modulation response and analog link performance. Link results on an integrated SGDBR-SOA-EAM device includes a sub-octave SFDR in the 125 to 127 dB/Hz4/5 range and a broadband SFDR of 103-107 dB/Hz2/3 limited by third order intermodulation products or 95-98 dB/Hz1/2, limited by second order intermodulation products, over a 1528 to 1573 nm wavelength range.

  17. Analog CMOS circuit design and characterization for optical coherence tomography signal processing.

    Science.gov (United States)

    Kariya, Rajesh; Mathine, David L; Barton, Jennifer K

    2004-12-01

    We have developed a custom analog CMOS circuit to perform the signal processing for an optical coherence tomography imaging system. The circuit is realized in a 1.5 microm low-noise analog CMOS technology. The circuitry extracts the Doppler frequency from the signal and electrically mixes this with the original signal to provide a filtered A-scan. The circuitry was used to produce a two-dimensional image of an onion.

  18. Absolute calibration of photon-number-resolving detectors with an analog output using twin beams

    Science.gov (United States)

    Peřina, Jan; Haderka, Ondřej; Allevi, Alessia; Bondani, Maria

    2014-01-01

    A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

  19. Refinement of Research Surveying in Software Methodologies by Analogy: finding your patch

    Directory of Open Access Journals (Sweden)

    Eugene Doroshenko

    1999-05-01

    Full Text Available To enhance research surveying in software methodologies, a model is introduced that can indicate field maturity based on vocabulary and relevant literature. This model is developed by drawing analogies with software methodologies. Two analogies are used: software models and software life cycles or processes. How this model can reduce research surveying problems for researchers is described using extracts from application results as examples. Although the model does support research surveying activities, it cannot choose the subject for the researcher.

  20. Absolute calibration of photon-number-resolving detectors with an analog output using twin beams

    Energy Technology Data Exchange (ETDEWEB)

    Peřina, Jan, E-mail: jan.perina.jr@upol.cz [RCPTM, Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 77146 Olomouc (Czech Republic); Haderka, Ondřej [Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 771 46 Olomouc (Czech Republic); Allevi, Alessia [Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell' Insubria, I-22100 Como (Italy); Bondani, Maria [Istituto di Fotonica e Nanotecnologie, CNR-IFN, I-22100 Como (Italy)

    2014-01-27

    A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

  1. Invention through Form and Function Analogy

    Science.gov (United States)

    Rule, Audrey C.

    2015-01-01

    "Invention through Form and Function Analogy" is an invention book for teachers and other leaders working with youth who are involving students in the invention process. The book consists of an introduction and set of nine learning cycle formatted lessons for teaching the principles of invention through the science and engineering design…

  2. Classical Analog of Electromagnetically Induced Transparency

    CERN Document Server

    Alzar, C L G; Nussenzveig, P

    2002-01-01

    We present a classical analog for Electromagnetically Induced Transparency (EIT). In a system of just two coupled harmonic oscillators subject to a harmonic driving force we can reproduce the phenomenology observed in EIT. We describe a simple experiment performed with two linearly coupled RLC circuits which can be taught in an undergraduate laboratory class.

  3. Analog of Superradiance effect in BEC

    CERN Document Server

    Basak, S

    2005-01-01

    We investigate the scattering of phase oscillation of Bose-Einstein Condensate by a 'draining of bathtub' type fluid motion. We derive a relation between the reflection and transmission coefficients which exhibits existence of analog of 'Superradiance effect' in BEC vortex with sink.

  4. C4913 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1996-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course C4913 Analog and Digital Filters...

  5. Analog Acoustic Expression in Speech Communication

    Science.gov (United States)

    Shintel, Hadas; Nusbaum, Howard C.; Okrent, Arika

    2006-01-01

    We present the first experimental evidence of a phenomenon in speech communication we call "analog acoustic expression." Speech is generally thought of as conveying information in two distinct ways: discrete linguistic-symbolic units such as words and sentences represent linguistic meaning, and continuous prosodic forms convey information about…

  6. A Mechanical Analogy for Ohm's Law.

    Science.gov (United States)

    do Couto Tavares, Milton; And Others

    1991-01-01

    A mechanical analogy between the microscopic motion of a charged carrier in an ordinary resistor and the macroscopic motion of a ball falling along a slanted board covered with a lattice of nails is introduced. The Drude model is also introduced to include the case of inelastic collisions. Computer simulation of the motion is described. (KR)

  7. CMOS circuits for analog signal processing

    NARCIS (Netherlands)

    Wallinga, Hans

    1988-01-01

    Design choices in CMOS analog signal processing circuits are presented. Special attention is focussed on continuous-time filter technologies. The basics of MOSFET-C continuous-time filters and CMOS Square Law Circuits are explained at the hand of a graphical MOST characteristics representation.

  8. A physical analogy to fuzzy clustering

    DEFF Research Database (Denmark)

    Jantzen, Jan

    2004-01-01

    This tutorial paper provides an interpretation of the membership assignment in the fuzzy clustering algorithm fuzzy c-means. The membership of a data point to several clusters is shown to be analogous to the gravitational forces between bodies of mass. This provides an alternative way to explain...

  9. Analogies and Reconstruction of Mathematical Knowledge.

    Science.gov (United States)

    Fast, Gerald R.

    An investigation was conducted to determine the effectiveness of utilizing analogies to effect conceptual change in mathematics. Forty-one high school seniors participated in a knowledge reconstruction process regarding their beliefs about everyday probability situations such as sports events or lotteries. These mathematics students were given…

  10. Analogy and mathematical reasoning : a survey

    OpenAIRE

    Miller, C. D. F.

    1983-01-01

    We survey the literature of Artificial Intelligence, and other related work, pertaining to the modelling of mathematical reasoning and its relationship with the use of analogy. In particular, we discuss the contribution of Lenat's program AM to models of mathematical discovery and concept-formation. We consider the use of similarity measures to structure a knowledge space and their role in concept acquisition.

  11. An iconic, analogical approach to grammaticalization

    NARCIS (Netherlands)

    Fischer, O.; Conradie, C.J.; Johl, R.; Beukes, M.; Fischer, O.; Ljungberg, C.

    2010-01-01

    This paper addresses a number of problems connected with the ‘apparatus’ used in grammaticalization theory. It will be argued that we get a better grip on what happens in processes of grammaticalization (and its ‘opposite’, lexicalization) if the process is viewed in terms of analogical processes, w

  12. Bootstrapped Low-Voltage Analog Switches

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    1999-01-01

    Novel low-voltage constant-impedance analog switch circuits are proposed. The switch element is a single MOSFET, and constant-impedance operation is obtained using simple circuits to adjust the gate and bulk voltages relative to the switched signal. Low-voltage (1-volt) operation is made feasible...

  13. A physical analogy to fuzzy clustering

    DEFF Research Database (Denmark)

    Jantzen, Jan

    2004-01-01

    This tutorial paper provides an interpretation of the membership assignment in the fuzzy clustering algorithm fuzzy c-means. The membership of a data point to several clusters is shown to be analogous to the gravitational forces between bodies of mass. This provides an alternative way to explain ...

  14. An iconic, analogical approach to grammaticalization

    NARCIS (Netherlands)

    Fischer, O.; Conradie, C.J.; Johl, R.; Beukes, M.; Fischer, O.; Ljungberg, C.

    2010-01-01

    This paper addresses a number of problems connected with the ‘apparatus’ used in grammaticalization theory. It will be argued that we get a better grip on what happens in processes of grammaticalization (and its ‘opposite’, lexicalization) if the process is viewed in terms of analogical processes, w

  15. Compact Structural Test Generation for Analog Macros

    NARCIS (Netherlands)

    Kaal, V.; Kerkhoff, Hans G.

    1997-01-01

    A structural, fault-model based methodology for the generation of compact high-quality test sets for analog macros is presented. Results are shown for an IV-converter macro design. Parameters of so-called test configurations are optimized for detection of faults in a fault-list and an optimal

  16. The GMO-Nanotech (Dis)Analogy?

    Science.gov (United States)

    Sandler, Ronald; Kay, W. D.

    2006-01-01

    The genetically-modified-organism (GMO) experience has been prominent in motivating science, industry, and regulatory communities to address the social and ethical dimensions of nanotechnology. However, there are some significant problems with the GMO-nanotech analogy. First, it overstates the likelihood of a GMO-like backlash against…

  17. C4913 ANALOGE OG DIGITALE FILTRE

    DEFF Research Database (Denmark)

    Gaunholt, Hans

    1996-01-01

    Theese lecture notes treats the fundamental theory and the most commonly used design methods for passive- active and digital filters with special emphasis on microelectronic realizations. The lecture notes covers 75% of the material taught in the course C4913 Analog and Digital Filters...

  18. Generating Analog IC Layouts with LAYGEN II

    CERN Document Server

    Martins, Ricardo M F; Horta, Nuno C G

    2013-01-01

    This book presents an innovative methodology for the automatic generation of analog integrated circuits (ICs) layout, based on template descriptions and on evolutionary computational techniques. A design automation tool, LAYGEN II, was implemented to validate the proposed approach giving special emphasis to reusability of expert design knowledge and to efficiency on retargeting operations.

  19. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  20. Performance of the Analog Moving Window Detector

    DEFF Research Database (Denmark)

    Hansen, V. Gregers

    1970-01-01

    A type of analog integrating moving window detector for use with a scanning pulse radar is examined. A performance analysis is carried out, which takes into account both the radiation pattern of the antenna and the dynamic character of the detection process due to the angular scanning...

  1. The GMO-Nanotech (Dis)Analogy?

    Science.gov (United States)

    Sandler, Ronald; Kay, W. D.

    2006-01-01

    The genetically-modified-organism (GMO) experience has been prominent in motivating science, industry, and regulatory communities to address the social and ethical dimensions of nanotechnology. However, there are some significant problems with the GMO-nanotech analogy. First, it overstates the likelihood of a GMO-like backlash against…

  2. Analogy between thermal convective and magnetohydrodynamic instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Valdmanis, Ya.Ya.; Kukainis, O.A.

    1977-01-01

    An examination is made of the analogy between thermo-convective instability and instability produced by various electromagnetic forces both in steady and alternating thermal and electromagnetic fields. An example is given for calculating an assumed bubble instability which could occur in an alternating magnetic field. 17 references.

  3. Identification of Protein Substrates of Specific PARP Enzymes Using Analog-Sensitive PARP Mutants and a "Clickable" NAD(+) Analog.

    Science.gov (United States)

    Gibson, Bryan A; Kraus, W Lee

    2017-01-01

    The PARP family of ADP-ribosyl transferases contains 17 members in human cells, most of which catalyze the transfer of the ADP-ribose moiety of NAD(+) onto their target proteins. This posttranslational modification plays important roles in cellular signaling, especially during cellular stresses, such as heat shock, inflammation, unfolded protein responses, and DNA damage. Knowing the specific proteins that are substrates for individual PARPs, as well as the specific amino acid residues in a given target protein that are ADP-ribosylated, is a key step in understanding the biology of individual PARPs. Recently, we developed a robust NAD(+) analog-sensitive approach for PARPs, which allows PARP-specific ADP-ribosylation of substrates that is suitable for subsequent copper-catalyzed azide-alkyne cycloaddition ("click chemistry") reactions. When coupled with proteomics and mass spectrometry, the analog-sensitive PARP approach can be used to identify the specific amino acids that are ADP-ribosylated by individual PARP proteins. In this chapter, we describe the key facets of the experimental design and application of the analog-sensitive PARP methodology to identify site-specific modification of PARP target proteins.

  4. De Analogía a Digitalia

    Directory of Open Access Journals (Sweden)

    Dr. Xaime Fandiño Alonso

    2001-01-01

    ía, creatividad y contenidos.ABSTRACTThe transition towards binary-based technology has unleashed dramatic changes that in the last decade have affected the different stages involved in an audiovisual production: from scripting and creating a project, through the various technological procedures of the actual production process to its final distribution.The remains of the analogical era are finally sinking under a seemingly unstoppable wave of constantly evolving new digital environments.The new hardware devices used in this field are mainly prototypes. An ever evolving market, the constant arising of new competitors, newborn joint-ventures and a myriad of related facts force technology providers to keep a pace of constant updating in a mad race of fierce competition.The old system which implied one machine for each process is increasingly becoming a memory of the past. Today new devices are being launched at such a speed that the old technological approach which dealt with mechanical appliances like magnetoscopes, closed platforms and linear recording are already bound for extinction.It’s only natural then that the sacred cows of the industry fear for their position. Big and small are elusive concepts in this new audiovisual frenzy. Its almost daily routine to read about big audiovisual corporations announcing mergers, buy-outs or the acquisition of a stake in new and small creativity and development firms built from scratch by young entrepreneurs out of the blue.The digital era is drawing a heavy curtain that luckily leaves behind an analogical era in which the ownership of the costly means of production was the most important card in the game. The artist could only exercise its art if access to the professional team and technical equipment required for an audiovisual work was granted by its proprietors.Today, digital means new systems with far more productive environments which besides are user-friendly and cost only a small fraction of the old hardware.Right now, with

  5. The role of analogies in learning to read.

    Science.gov (United States)

    Kamhi, A G; Laing, S P

    2000-01-01

    A number of factors contribute to proficient word recognition, including phonological awareness and the ability to make orthographic analogies. The present study considered the relative contribution analogy abilities make toward early reading ability. Two analogy tasks and measures of phonological awareness, orthographic knowledge, visual memory, general language ability, and non-verbal intelligence were administered to 20 second grade good readers and 20 third and fourth grade poor readers. The analogy tasks did make a significant contribution to early reading ability; however, the analogy tasks were not very different from the measures of reading they predicted. In other words, it seems difficult to isolate the use of analogies from basic phonological decoding abilities.

  6. delta C-13 Analysis of Mars Analog Carbonates Using Evolved Gas Cavity - Ringdown Spectrometry on the 2010 Arctic Mars Analog Svalbard Expedition (AMASE)

    Science.gov (United States)

    Stern, J. C.; McAdam, A. C.; ten Kate, I. L.; Mahaffy, P. R.; Steele, A.; Amundson, H. E. F.

    2011-01-01

    The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two distinct geologic settings on Svalbard, using instrumentation and techniques in development for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return (MSR). The Sample Analysis at Mars (SAM) instrument suite, which will fly on MSL, was developed at Goddard Space Flight Center (GSFC), together with several partners. SAM consists of a quadrupole mass spectrometer (QMS), a gas chromatograph CGC), and a tunable laser spectrometer (TLS), which all analyze gases created by evolved gas analysis (EGA). The two sites studied represent "biotic" and "abiotic" analogs; the "biotic" site being the Knorringfjell fossil methane seep, and the "abiotic" site being the basaltic Sigurdfjell vent complex. The data presented here represent experiments to measure the carbon isotopic composition of carbonates from these two analogs using evolved gas analysis coupled with a commercial cavity ringdown CO2 isotopic analyzer (Picarro) as a proxy for the TLS on SAM.

  7. Mechatronics by Analogy and Application to Legged Locomotion

    Science.gov (United States)

    Ragusila, Victor

    A new design methodology for mechatronic systems, dubbed as Mechatronics by Analogy (MbA), is introduced and applied to designing a leg mechanism. The new methodology argues that by establishing a similarity relation between a complex system and a number of simpler models it is possible to design the former using the analysis and synthesis means developed for the latter. The methodology provides a framework for concurrent engineering of complex systems while maintaining the transparency of the system behaviour through making formal analogies between the system and those with more tractable dynamics. The application of the MbA methodology to the design of a monopod robot leg, called the Linkage Leg, is also studied. A series of simulations show that the dynamic behaviour of the Linkage Leg is similar to that of a combination of a double pendulum and a spring-loaded inverted pendulum, based on which the system kinematic, dynamic, and control parameters can be designed concurrently. The first stage of Mechatronics by Analogy is a method of extracting significant features of system dynamics through simpler models. The goal is to determine a set of simpler mechanisms with similar dynamic behaviour to that of the original system in various phases of its motion. A modular bond-graph representation of the system is determined, and subsequently simplified using two simplification algorithms. The first algorithm determines the relevant dynamic elements of the system for each phase of motion, and the second algorithm finds the simple mechanism described by the remaining dynamic elements. In addition to greatly simplifying the controller for the system, using simpler mechanisms with similar behaviour provides a greater insight into the dynamics of the system. This is seen in the second stage of the new methodology, which concurrently optimizes the simpler mechanisms together with a control system based on their dynamics. Once the optimal configuration of the simpler system is

  8. Airframe Noise Prediction by Acoustic Analogy: Revisited

    Science.gov (United States)

    Farassat, F.; Casper, Jay H.; Tinetti, A.; Dunn, M. H.

    2006-01-01

    The present work follows a recent survey of airframe noise prediction methodologies. In that survey, Lighthill s acoustic analogy was identified as the most prominent analytical basis for current approaches to airframe noise research. Within this approach, a problem is typically modeled with the Ffowcs Williams and Hawkings (FW-H) equation, for which a geometry-independent solution is obtained by means of the use of the free-space Green function (FSGF). Nonetheless, the aeroacoustic literature would suggest some interest in the use of tailored or exact Green s function (EGF) for aerodynamic noise problems involving solid boundaries, in particular, for trailing edge (TE) noise. A study of possible applications of EGF for prediction of broadband noise from turbulent flow over an airfoil surface and the TE is, therefore, the primary topic of the present work. Typically, the applications of EGF in the literature have been limited to TE noise prediction at low Mach numbers assuming that the normal derivative of the pressure vanishes on the airfoil surface. To extend the application of EGF to higher Mach numbers, the uniqueness of the solution of the wave equation when either the Dirichlet or the Neumann boundary condition (BC) is specified on a deformable surface in motion. The solution of Lighthill s equation with either the Dirichlet or the Neumann BC is given for such a surface using EGFs. These solutions involve both surface and volume integrals just like the solution of FW-H equation using FSGF. Insight drawn from this analysis is evoked to discuss the potential application of EGF to broadband noise prediction. It appears that the use of a EGF offers distinct advantages for predicting TE noise of an airfoil when the normal pressure gradient vanishes on the airfoil surface. It is argued that such an approach may also apply to an airfoil in motion. However, for the prediction of broadband noise not directly associated with a trailing edge, the use of EGF does not

  9. Upgrading microwave telemetry data communications with an analog lightwave system

    Science.gov (United States)

    Reynolds, Harrell D., Jr.

    The work performed in replacing four microwave telemetry data communications systems with one single analog fiber-optics system at Edwards Air Force Base is described. The fiber-optic system used was initially designed for use in a television video system, and thus a method of aligning the fiber-optic system to meet the needs of the transmission system was required. The objectives were met by utilizing several well-known methods of AM and FM measurement techniques not yet described in the implementation of fiber-optic communications systems. After alignment, the system transmitted the already developed basebands as well as the original microwave equipment.

  10. The Problem of Analogical Inference in Inductive Logic

    Directory of Open Access Journals (Sweden)

    Simon M. Huttegger

    2016-06-01

    Full Text Available We consider one problem that was largely left open by Rudolf Carnap in his work on inductive logic, the problem of analogical inference. After discussing some previous attempts to solve this problem, we propose a new solution that is based on the ideas of Bruno de Finetti on probabilistic symmetries. We explain how our new inductive logic can be developed within the Carnapian paradigm of inductive logic-deriving an inductive rule from a set of simple postulates about the observational process-and discuss some of its properties.

  11. Drilling Automation Tests At A Lunar/Mars Analog Site

    Science.gov (United States)

    Glass, B.; Cannon, H.; Hanagud, S.; Lee, P.; Paulsen, G.

    2006-01-01

    Future in-situ lunar/martian resource utilization and characterization, as well as the scientific search for life on Mars, will require access to the subsurface and hence drilling. Drilling on Earth is hard - an art form more than an engineering discipline. The limited mass, energy and manpower in planetary drilling situations makes application of terrestrial drilling techniques problematic. The Drilling Automation for Mars Exploration (DAME) project is developing drilling automation and robotics for projected use in missions to the Moon and Mars in the 2011-15 period. This has been tested recently, drilling in permafrost at a lunar/martian analog site (Haughton Crater, Devon Island, Canada).

  12. A Novel Green Synthesis of Thalidomide and Analogs

    Directory of Open Access Journals (Sweden)

    Ellis Benjamin

    2017-01-01

    Full Text Available Thalidomide and its derivatives are currently under investigation for their antiangiogenic, immunomodulative, and anticancer properties. Current methods used to synthesize these compounds involve multiple steps and extensive workup procedures. Described herein is an efficient microwave irradiation green synthesis method that allows preparation of thalidomide and its analogs in a one-pot multicomponent synthesis system. The multicomponent synthesis system developed involves an array of cyclic anhydrides, glutamic acid, and ammonium chloride in the presence of catalytic amounts of 4-N,N-dimethylaminopyridine (DMAP to produce thalidomide and structurally related compounds within minutes in good isolated yields.

  13. Playing with a double-edged sword: Analogies in biochemistry

    Science.gov (United States)

    Orgill, Marykay

    Analogy pervades our everyday reasoning. No situation we encounter is exactly like a situation we have encountered previously, and our ability to learn and survive in the world is based on our ability to find similarities between past and present situations and use the knowledge we have gained from past situations to manage current situations. Analogies can be powerful teaching tools because they can make new material intelligible to students by comparing it to material that is already familiar. It is clear, though, that not all analogies are good and that not all good analogies are useful to all students. In this study, I have used textbook analysis, classroom observations, student interviews and instructor interviews to determine the role that analogies play in biochemistry learning. Analogies are an important teaching technique in biochemistry classes, being used more often in both biochemistry classes and textbooks than they are in high school chemistry classes and textbooks. Most biochemistry students like, pay particular attention to, and remember the analogies their instructors provide; and they use these analogies to understand, visualize, and recall information from class. Even though students like and use analogies, they do not understand what analogies are or the mechanism by which they improve learning. For the students, analogies are simply any teaching technique that eases understanding, visualization, or recall. Instructors, on the other hand, have a good understanding of what analogies are and of how they should be presented in class; but they do not use analogies as effectively as they should. They do not plan, explain or identify the limitations of the analogies they use in class. However, regardless of how effectively instructors present analogies in class, this study indicates that, in general, analogies are useful in promoting understanding, visualization, recall, and motivation in biochemistry students at all levels. They would be even more

  14. Synthesis and Evaluation of Desmethyl Azumamide Analogs

    DEFF Research Database (Denmark)

    Maolanon, Alex

    the azumamide analogs; however, removal of the methyl group had a significant impact relative to the natural products. To understand this effect, the NMR structure was solved with the assistance from Casper Hoeck and Charlotte H. Gotfredsen and docked conformations were obtained from Niels J. Christensen...... and Peter Fristrup. Compared to the natural compounds, the 3Dstructure of the scaffold in the azumamide analogs were similar. Although a conclusion was not found, the preliminary docking results indicated favorable lipophilic interaction with the methyl group in the azumamides. Largazole is another...... macrocylic natural product with HDAC inhibitory activity. The compound has a thioester functionality in the side chain, which is hydrolyzed before interaction with the enzymes. In the attempt to mimic the prodrug nature of largazole, compounds containing a thiol group were designed, as it was hypothesized...

  15. Analog fault diagnosis by inverse problem technique

    KAUST Repository

    Ahmed, Rania F.

    2011-12-01

    A novel algorithm for detecting soft faults in linear analog circuits based on the inverse problem concept is proposed. The proposed approach utilizes optimization techniques with the aid of sensitivity analysis. The main contribution of this work is to apply the inverse problem technique to estimate the actual parameter values of the tested circuit and so, to detect and diagnose single fault in analog circuits. The validation of the algorithm is illustrated through applying it to Sallen-Key second order band pass filter and the results show that the detecting percentage efficiency was 100% and also, the maximum error percentage of estimating the parameter values is 0.7%. This technique can be applied to any other linear circuit and it also can be extended to be applied to non-linear circuits. © 2011 IEEE.

  16. Optimal neural computations require analog processors

    Energy Technology Data Exchange (ETDEWEB)

    Beiu, V.

    1998-12-31

    This paper discusses some of the limitations of hardware implementations of neural networks. The authors start by presenting neural structures and their biological inspirations, while mentioning the simplifications leading to artificial neural networks. Further, the focus will be on hardware imposed constraints. They will present recent results for three different alternatives of parallel implementations of neural networks: digital circuits, threshold gate circuits, and analog circuits. The area and the delay will be related to the neurons` fan-in and to the precision of their synaptic weights. The main conclusion is that hardware-efficient solutions require analog computations, and suggests the following two alternatives: (i) cope with the limitations imposed by silicon, by speeding up the computation of the elementary silicon neurons; (2) investigate solutions which would allow the use of the third dimension (e.g. using optical interconnections).

  17. Parabolic flight as a spaceflight analog.

    Science.gov (United States)

    Shelhamer, Mark

    2016-06-15

    Ground-based analog facilities have had wide use in mimicking some of the features of spaceflight in a more-controlled and less-expensive manner. One such analog is parabolic flight, in which an aircraft flies repeated parabolic trajectories that provide short-duration periods of free fall (0 g) alternating with high-g pullout or recovery phases. Parabolic flight is unique in being able to provide true 0 g in a ground-based facility. Accordingly, it lends itself well to the investigation of specific areas of human spaceflight that can benefit from this capability, which predominantly includes neurovestibular effects, but also others such as human factors, locomotion, and medical procedures. Applications to research in artificial gravity and to effects likely to occur in upcoming commercial suborbital flights are also possible. Copyright © 2016 the American Physiological Society.

  18. Interference Alignment with Analog Channel State Feedback

    CERN Document Server

    Ayach, Omar El

    2010-01-01

    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel with an arbitrary number of users. While the achieved sum rate with IA is much higher than previously thought possible, the improvement comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet costly approach that incurs large overhead and limits throughput. We propose using analog feedback as an alternative to limited feedback or reciprocity based alignment. We show that the full multiplexing gain observed with perfect channel knowledge is preserved by analog feedback and the mean loss in sum rate is bounded by a constant when signal-to-noise ratio is comparable in both forward and feedback channels. When such feedback quality is not quite possible, a fraction of the degrees of freedom is achieved. We consider the overhead of training and feedback and use this framework to optimize the system's effective throughput...

  19. Atomtronics: Ultracold Atom Analogs of Electronic Devices

    Science.gov (United States)

    2006-06-23

    dIc/dIB. ( PNP ). For our discussion, we consider an NPN tran- These key features of an electronic transistor can be sistor. A detailed discussion of...voltage curve exploits the existence of superfluid and insulating regimes in the phase diagram. "lie atomt.roinc analog of a bipolar junction transistor ...of a bipolar junction transistor exhibits large negative gain. Our results provide the building blocks for more advanced atomtronic devices and

  20. Transition State Analog Inhibitors for Esterases.

    Science.gov (United States)

    1983-06-02

    Propanones." SCIENTIFIC PERSONNEL SUPPORTED BY THIS PROJECT AND DEGREES AWARDED DURING THIS REPORTING PERIOD Dr. Alan Dafforn Dr. Antoon Brouwer Dr. John P...294, Raven Press, New York. 11. Hansch, C. and Leo , A., (1979) "Substituent Constants for Correlation Analysis in Chemistry and Biology," pp. 69-70...BORONIC ACIDS AS 1INSITION STATE ANALOG INHIBITORS OF ACTYLCHOLINESTERASE by Alan Dafforn and Antoon C. Brouwer Department of Chemistry Bowling Green

  1. Analog-digital codesign using coarse quantization

    Science.gov (United States)

    Kokkeler, Andre Bernardus Joseph

    With regards to electronic systems, two important trends can be observed. The first trend is generally known as Moore's law: the digital processing capacity per chip is increasing a factor two every 18 months. Another part of the first trend is that the performance increase of integrated linear or analog processing is slow, a factor two every 4.7 years. The second trend is that the rate of data exchange between electronic systems is increasing rapidly. Because of these high data rates especially the design of data converters from analog to digital (ADCs) is demanding. For a specific set of applications, the requirements for the ADC can be relaxed by reducing the resolution of the conversion from analog to digital. Within these specific applications, signal characteristics rather than instantaneous values of the signal are determined. Reducing the resolution to an extreme extend is called 'coarse quantization'. The design of mixed signal systems is guided by a Y-chart design methodology. Analog-Digital Codesign, guided by the Y-chart approach, leads to mixed-signal systems with reduced costs compared to systems designed with the traditional methodology. The Y-chart approach also enables the use of coarse quantization as an additional design parameter to further reduce costs. This is illustrated by two case studies. The first case study concentrates on the design of a digital predistorter for Power Amplifiers (PAs) in telecommunication transmitters. In the second case study, we reconsider the design of a part of a Radio Telescope, used for Radio Astronomy. This part is called the Tied Array Adder and it sums signals from different telescopes. Both case studies show that coarse quantization can lead to mixed-signal systems with lower costs but system parameters will change. The explicit reconsideration of functional specifications, facilitated by the Y-chart approach, is therefore essential for the introduction of coarse quantization.

  2. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    OpenAIRE

    Mihali, Troco K; Moffitt, Michelle C.; Neilan, Brett A.; Maria Wiese; D’Agostino, Paul M.

    2010-01-01

    Saxitoxin (STX) and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs). PSTs are the causative agents of paralytic shellfish poisoning (PSP) and are mostly associated with marine dinoflagellates (eukaryotes) and freshwater cyanobacteria (prokaryotes), which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified...

  3. Quantum Electric Circuits Analogous to Ballistic Conductors

    OpenAIRE

    2007-01-01

    The conductance steps in a constricted two-dimensional electron gas and the minimum conductivity in graphene are related to a new uncertainty relation between electric charge and conductance in a quantized electric circuit that mimics the electric transport in mesoscopic systems. This uncertainty relation makes specific use of the discreteness of electric charge. Quantum electric circuits analogous to both constricted two-dimensional electron gas and graphene are introduced. In the latter cas...

  4. Survey of Evaluated Isobaric Analog States

    Energy Technology Data Exchange (ETDEWEB)

    MacCormick, M., E-mail: maccorm@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS/IN2P3, Université Paris-Sud, 91406 Orsay CEDEX (France); Audi, G. [Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, CNRS/IN2P3, Université Paris-Sud, Bât. 108, F-91405 Orsay Campus (France)

    2014-06-15

    Isobaric analog states (IAS) can be used to estimate the masses of members belonging to the same isospin multiplet. Experimental and estimated IAS have been used frequently within the Atomic Mass Evaluation (AME) in the past, but the associated set of evaluated masses have been published for the first time in AME2012 and NUBASE2012. In this paper the current trends of the isobaric multiplet mass equation (IMME) coefficients are shown. The T = 2 multiplet is used as a detailed illustration.

  5. An introduction to analog and digital communications

    CERN Document Server

    Haykin, Simon

    2012-01-01

    The second edition of this accessible book provides readers with an introductory treatment of communication theory as applied to the transmission of information-bearing signals. While it covers analog communications, the emphasis is placed on digital technology. It begins by presenting the functional blocks that constitute the transmitter and receiver of a communication system. Readers will next learn about electrical noise and then progress to multiplexing and multiple access techniques.

  6. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  7. Clinical utility of insulin and insulin analogs

    Science.gov (United States)

    Sanlioglu, Ahter D.; Altunbas, Hasan Ali; Balci, Mustafa Kemal; Griffith, Thomas S.; Sanlioglu, Salih

    2013-01-01

    Diabetes is a pandemic disease characterized by autoimmune, genetic and metabolic abnormalities. While insulin deficiency manifested as hyperglycemia is a common sequel of both Type-1 and Type-2 diabetes (T1DM and T2DM), it does not result from a single genetic defect—rather insulin deficiency results from the functional loss of pancreatic β cells due to multifactorial mechanisms. Since pancreatic β cells of patients with T1DM are destroyed by autoimmune reaction, these patients require daily insulin injections. Insulin resistance followed by β cell dysfunction and β cell loss is the characteristics of T2DM. Therefore, most patients with T2DM will require insulin treatment due to eventual loss of insulin secretion. Despite the evidence of early insulin treatment lowering macrovascular (coronary artery disease, peripheral arterial disease and stroke) and microvascular (diabetic nephropathy, neuropathy and retinopathy) complications of T2DM, controversy exists among physicians on how to initiate and intensify insulin therapy. The slow acting nature of regular human insulin makes its use ineffective in counteracting postprandial hyperglycemia. Instead, recombinant insulin analogs have been generated with a variable degree of specificity and action. Due to the metabolic variability among individuals, optimum blood glucose management is a formidable task to accomplish despite the presence of novel insulin analogs. In this article, we present a recent update on insulin analog structure and function with an overview of the evidence on the various insulin regimens clinically used to treat diabetes. PMID:23584214

  8. Theory of analogous force on number sets

    Science.gov (United States)

    Canessa, Enrique

    2003-10-01

    A general statistical thermodynamic theory that considers given sequences of x-integers to play the role of particles of known type in an isolated elastic system is proposed. By also considering some explicit discrete probability distributions px for natural numbers, we claim that they lead to a better understanding of probabilistic laws associated with number theory. Sequences of numbers are treated as the size measure of finite sets. By considering px to describe complex phenomena, the theory leads to derive a distinct analogous force fx on number sets proportional to (∂ px/∂ x) T at an analogous system temperature T. In particular, this leads to an understanding of the uneven distribution of integers of random sets in terms of analogous scale invariance and a screened inverse square force acting on the significant digits. The theory also allows to establish recursion relations to predict sequences of Fibonacci numbers and to give an answer to the interesting theoretical question of the appearance of the Benford's law in Fibonacci numbers. A possible relevance to prime numbers is also analyzed.

  9. Quantifying Uncertainty of Wind Power Production Through an Analog Ensemble

    Science.gov (United States)

    Shahriari, M.; Cervone, G.

    2016-12-01

    The Analog Ensemble (AnEn) method is used to generate probabilistic weather forecasts that quantify the uncertainty in power estimates at hypothetical wind farm locations. The data are from the NREL Eastern Wind Dataset that includes more than 1,300 modeled wind farms. The AnEn model uses a two-dimensional grid to estimate the probability distribution of wind speed (the predictand) given the values of predictor variables such as temperature, pressure, geopotential height, U-component and V-component of wind. The meteorological data is taken from the NCEP GFS which is available on a 0.25 degree grid resolution. The methodology first divides the data into two classes: training period and verification period. The AnEn selects a point in the verification period and searches for the best matching estimates (analogs) in the training period. The predictand value at those analogs are the ensemble prediction for the point in the verification period. The model provides a grid of wind speed values and the uncertainty (probability index) associated with each estimate. Each wind farm is associated with a probability index which quantifies the degree of difficulty to estimate wind power. Further, the uncertainty in estimation is related to other factors such as topography, land cover and wind resources. This is achieved by using a GIS system to compute the correlation between the probability index and geographical characteristics. This study has significant applications for investors in renewable energy sector especially wind farm developers. Lower level of uncertainty facilitates the process of submitting bids into day ahead and real time electricity markets. Thus, building wind farms in regions with lower levels of uncertainty will reduce the real-time operational risks and create a hedge against volatile real-time prices. Further, the links between wind estimate uncertainty and factors such as topography and wind resources, provide wind farm developers with valuable

  10. In Pursuit of Analogs for Europa's Dynamics & Potential Habitats

    Science.gov (United States)

    Schmidt, Britney E.; Blankenship, D. D.; Greenbaum, J. S.; Young, D. A.

    2010-10-01

    Future Europa exploration will seek to characterize the distribution of shallow subsurface water as well as to understand the formation of surface features through dynamic ice-shell processes. Radar sounding will be a critical tool for imaging these features, and should be of primary interest to the astrobiology community for understanding how and where life might arise on Europa. To develop successful instrumentation and data interpretation techniques for exploring Europa, we must leverage analogous terrestrial environments and processes. Airborne ice penetrating radar is now a mature tool in terrestrial studies of Earth's ice sheets, and orbital examples have been successfully deployed at Earth's Moon and Mars. It is a distinct possibility that water within or just below the ice on Europa has played a role in forming some of its dynamic terrain. Observations of rotated blocks and dark floor materials may suggest that brines existed in the near subsurface and enabled the formation of such features. The University of Texas High Capability Airborne Radar Sounder (HiCARS) developed to study Antarctic ice sheet dynamics has been configured to test observation scenarios for Europa. We discuss recent results from the 60 MHz HiCARS system over brine infiltrated Antarctic marine ice as an analog for processes affecting the formation of pits and chaos. Basal melt occurring below terrestrial marine ice is directly analogous to processes that may operate on Europa if the shell is "thin,” and will be similar to processes occurring instead within the ice sheet in the case of a thicker, multi-layer ice sheet where enriched brines may remain liquid within the shell. A key site for further investigation of conductive and "convective” ices is found in the polythermal glaciers in the Arctic, and the case for this exploration will be illuminated.

  11. Scientific Analogies and Their Use in Teaching Science

    Science.gov (United States)

    Kipnis, Nahum

    Analogy in science knew its successes and failures, as illustrated by examples from the eighteenth-century physics. At times, some scientists abstained from using a certain analogy on the ground that it had not yet been demonstrated. Several false discoveries in the 18th and early 19th centuries appeared to support their caution. It is now clear that such a position reflected a methodological confusion that resulted from a failure to distinguish between particular and general analogies. Considering analogy as a hierarchical structure provides a new insight into "testing an analogy". While warning science teachers of dangers associated with use of analogy, historical cases and their analysis provided here may encourage them to use analogy more extensively while avoiding misconceptions. An argument is made that the history of science may be a better guide than philosophy of science and cognitive psychology when it concerns the role of analogy in science and in teaching science for understanding.

  12. Using Analogs for Chemistry Problem Solving: Does It Increase Understanding?

    Science.gov (United States)

    Friedel, Arthur W.; And Others

    1990-01-01

    Discussed is the effectiveness of using analogies in chemistry instruction. Students' mathematics anxiety, spatial visualization skill, and proportional reasoning ability were found to be important aptitudes for determining chemistry achievement. The relationship between analogs and algorithms is described. (KR)

  13. Creative Analogy Use in a Heterogeneous Design Team

    DEFF Research Database (Denmark)

    Christensen, Bo; Ball, Linden J.

    2016-01-01

    the design dialogue derived from team members with highly disparate educational backgrounds. Our analyses revealed that analogies that matched (versus mismatched) educational backgrounds were generated and revisited more frequently, presumably because they were more accessible. Matching analogies were also...

  14. Developmental Patterns in the Solution of Verbal Analogies.

    Science.gov (United States)

    Sternberg, Robert J.; Nigro, Georgia

    1980-01-01

    Examines developmental patterns in the solution of verbal analogies. Twenty subjects in each of grades 3, 6, 9, and in college were tested on their relative abilities to solve 180 verbal analogies based on five different verbal relations. (CM)

  15. Solving Verbal Analogies: Some Cognitive Components of Intelligence Test Items

    Science.gov (United States)

    Whitely, Susan E.

    1976-01-01

    The results indicate that although relational concepts influence the cognitive aptitudes which are reflected in analogy item performance, success in solving analogies does not depend on individual differences in some major aspects of processing relationships. (Author/DEP)

  16. Accurate and Precise Computation Using Analog VLSI, with Applications to Computer Graphics and Neural Networks.

    Science.gov (United States)

    Kirk, David Blair

    This thesis develops an engineering practice and design methodology to enable us to use CMOS analog VLSI chips to perform more accurate and precise computation. These techniques form the basis of an approach that permits us to build computer graphics and neural network applications using analog VLSI. The nature of the design methodology focuses on defining goals for circuit behavior to be met as part of the design process. To increase the accuracy of analog computation, we develop techniques for creating compensated circuit building blocks, where compensation implies the cancellation of device variations, offsets, and nonlinearities. These compensated building blocks can be used as components in larger and more complex circuits, which can then also be compensated. To this end, we develop techniques for automatically determining appropriate parameters for circuits, using constrained optimization. We also fabricate circuits that implement multi-dimensional gradient estimation for a gradient descent optimization technique. The parameter-setting and optimization tools allow us to automatically choose values for compensating our circuit building blocks, based on our goals for the circuit performance. We can also use the techniques to optimize parameters for larger systems, applying the goal-based techniques hierarchically. We also describe a set of thought experiments involving circuit techniques for increasing the precision of analog computation. Our engineering design methodology is a step toward easier use of analog VLSI to solve problems in computer graphics and neural networks. We provide data measured from compensated multipliers built using these design techniques. To demonstrate the feasibility of using analog VLSI for more quantitative computation, we develop small applications using the goal-based design approach and compensated components. Finally, we conclude by discussing the expected significance of this work for the wider use of analog VLSI for

  17. A Reasoning System using Inductive Inference of Analogical Union

    OpenAIRE

    Miyahara, Tetsuhiro

    1988-01-01

    Analogical reasoning derives a new fact based on the analogous facts previously known. Inductive inference is a process of gaining a general rule from examples. We propose a new reasoning system using inductive inference and analogical reasoning. which is applicable to intellectual information processing and we characterize its power. Given an enumeration of paired examples. this system inductively infers a program representing the paring and constructs an analogical union. It reasons by anal...

  18. Prostaglandin-induced radioprotection of murine intestinal crypts and villi by a PGE diene analog (SC-44932) and a PGI analog (Iloprost)

    Science.gov (United States)

    Hanson, Wayne R.; Collins, Paul W.

    The aminothiols exemplified by WR-2721 are effective radioprotectors; however, their toxicity associated with hypotension, nausea, and emesis has limited their development for applications in medicine or in hazardous radiation environments. There is a need for new radioprotectors that have fewer toxic side effects when given alone or combined with reduced amounts of thiols. A variety of prostaglandins (PGs) have been shown to be radioprotective agents and some appear to have fewer toxic side effects than the aminothiols. Iloprost, a stable PGI, analog protects the clonogenic epithelial cells of intestinal crypts but does not protect epithelial cells of the villi. In contrast, an E-series omega chain diene analog designated SC-44932 protects epithelial cells of both crypts and villi. When the two are combined, protection of the crypts is additive and the villi are protected to the same degree as when SC-44932 is given alone. Since radioprotection for some PGs has been shown to be dependent upon receptors, we suggest that the pattern of radioprotection seen with these two analogs depend on the location of the respective receptors or on the ability of differentiated villus cells to respond to PGs. By studying different analogs, we hope to identify mechanisms associated with PG-induced radioprotection and to identify the most protective PG analogs for applications of radioprotection.

  19. A Kolmogorov Complexity View of Analogy: From Logical Modeling to Experimentations

    Science.gov (United States)

    Bayoudh, Meriam; Prade, Henri; Richard, Gilles

    Analogical reasoning is considered as one of the main mechanisms underlying human intelligence and creativity, allowing the paradigm shift essential to a creative process. More specific is the notion of analogical proportion like "2 is to 4 as 5 is to 10" or "read is to reader as lecture is to lecturer": such statements can be precisely described within an algebraic framework. When the proportion holds between concepts as in "engine is to car as heart is to human" or "wine is to France as beer is to England", applying an algebraic framework is less straightforward and a new way to understand analogical proportions on the basis of Kolmogorov complexity theory may seem more appropriate. This viewpoint has been used to develop a classifier detecting analogies in natural language. Despite their apparent difference, it is quite clear that the two viewpoints should be strongly related. In this paper, we investigate the link between a purely abstract view of analogical proportions and a definition based on Kolmogorov complexity theory. This theory is used as a backbone to experiment a classifier of natural language analogies whose results are consistent with the abstract setting.

  20. The Higgs mechanism and superconductivity: A case study of formal analogies

    Science.gov (United States)

    Fraser, Doreen; Koberinski, Adam

    2016-08-01

    Following the experimental discovery of the Higgs boson, physicists explained the discovery to the public by appealing to analogies with condensed matter physics. The historical root of these analogies is the analogies to models of superconductivity that inspired the introduction of spontaneous symmetry breaking (SSB) into particle physics in the early 1960s. We offer a historical and philosophical analysis of the analogies between the Higgs model of the electroweak (EW) interaction and the Ginsburg-Landau (GL) and Bardeen-Cooper-Schrieffer (BCS) models of superconductivity, respectively. The conclusion of our analysis is that both sets of analogies are purely formal in virtue of the fact that they are accompanied by substantial physical disanalogies. In particular, the formal analogies do not map the temporal, causal, or modal structures of SSB in superconductivity to temporal, causal, or modal structures in the Higgs model. These substantial physical disanalogies mean that analogies to models of superconductivity cannot supply the basis for the physical interpretation of EW SSB; however, an appreciation of the contrast between the physical interpretations of SSB in superconductivity and the Higgs model does help to clarify some foundational issues. Unlike SSB in superconductivity, SSB in the Higgs sector of the Standard Model (without the addition of new physics) is neither a temporal nor a causal process. We discuss the implications for the 'eating' metaphor for mass gain in the Higgs model. Furthermore, the distinction between the phenomenological GL model and the dynamical BCS model does not carry over to EW models, which clarifies the desiderata for the so-called 'dynamical' models of EW SSB (e.g., minimal technicolor). Finally, the development of the Higgs model is an illuminating case study for philosophers of science because it illustrates how purely formal analogies can play a fruitful heuristic role in physics.

  1. Investigating and Theorizing Discourse during Analogy Writing in Chemistry

    Science.gov (United States)

    Bellocchi, Alberto; Ritchie, Stephen M.

    2011-01-01

    Explanations of the role of analogies in learning science at a cognitive level are made in terms of creating bridges between new information and students' prior knowledge. In this empirical study of learning with analogies in an 11th grade chemistry class, we explore an alternative explanation at the "social" level where analogy shapes…

  2. Analogies in Medicine: Valuable for Learning, Reasoning, Remembering and Naming

    Science.gov (United States)

    Pena, Gil Patrus; Andrade-Filho, Jose de Souza

    2010-01-01

    Analogies are important tools in human reasoning and learning, for resolving problems and providing arguments, and are extensively used in medicine. Analogy and similarity involve a structural alignment or mapping between domains. This cognitive mechanism can be used to make inferences and learn new abstractions. Through analogies, we try to…

  3. Functional DNA: Teaching Infinite Series through Genetic Analogy

    Science.gov (United States)

    Kowalski, R. Travis

    2011-01-01

    This article presents an extended analogy that connects infinite sequences and series to the science of genetics, by identifying power series as "DNA for a function." This analogy allows standard topics such as convergence tests or Taylor approximations to be recast in a "forensic" light as mathematical analogs of genetic concepts such as DNA…

  4. The Role of Causal Models in Analogical Inference

    Science.gov (United States)

    Lee, Hee Seung; Holyoak, Keith J.

    2008-01-01

    Computational models of analogy have assumed that the strength of an inductive inference about the target is based directly on similarity of the analogs and in particular on shared higher order relations. In contrast, work in philosophy of science suggests that analogical inference is also guided by causal models of the source and target. In 3…

  5. Anti-inflammatory effect of thalidomide dithiocarbamate and dithioate analogs.

    Science.gov (United States)

    Talaat, Roba; El-Sayed, Waheba; Agwa, Hussein S; Gamal-Eldeen, Amira M; Moawia, Shaden; Zahran, Magdy A H

    2015-08-05

    Thalidomide has anti-inflammatory, immunomodulatory, and anti-angiogenic properties. It has been used to treat a variety of cancers and autoimmune diseases. This study aimed to characterize anti-inflammatory activities of novel thalidomide analogs by exploring their effects on splenocytes proliferation and macrophage functions and their antioxidant activity. MTT assay was used to assess the cytotoxic effect of thalidomide analogs against splenocytes. Tumor necrosis factor (TNF-α) and nuclear factor kappa B (NF-κB-P65) were determined by enzyme-linked immunosorbent assay (ELISA). Nitric oxide (NO) was estimated by colorimetric assay. Antioxidant activity was examined by ORAC assay. Our results demonstrated that thalidomide dithioate analog 2 and thalidomide dithiocarbamate analog 4 produced a slight increase in splenocyte proliferation compared with thalidomide. Thalidomide dithiocarbamate analog 1 is a potent inhibitor of TNF-α production, whereas thalidomide dithiocarbamate analog 5 is a potent inhibitor of both TNF-α and NO. Analog 2 has a pronounced inhibitory effect on NF-κB-P65 production level. All thalidomide analogs showed prooxidant activity against hydroxyl (OH) radical. Analog 1 and thalidomide dithioate analog 3 have prooxidant activity against peroxyl (ROO) radical in relation to thalidomide. On the other hand, analog 4 has a potent scavenging capacity against peroxyl (ROO) radical compared with thalidomide. Taken together, the results of this study suggest that thalidomide analogs might have valuable anti-inflammatory activities with more pronounced effect than thalidomide itself.

  6. Analogy Use in Eighth-Grade Mathematics Classrooms

    Science.gov (United States)

    Richland, Lindsey E.; Holyoak, Keith J.; Stigler, James W.

    2004-01-01

    Analogical reasoning has long been believed to play a central role in mathematics learning and problem solving (see Genter, Holyoak, & Kokinov, 2001); however, little is known about how analogy is used in everyday instructional contexts. This article examines analogies produced in naturally occurring U.S. mathematics lessons to explore…

  7. Analogical Instruction in Statistics: Implications for Social Work Educators

    Science.gov (United States)

    Thomas, Leela

    2008-01-01

    This paper examines the use of analogies in statistics instruction. Much has been written about the difficulty social work students have with statistics. To address this concern, Glisson and Fischer (1987) called for the use of analogies. Understanding of analogical problem solving has surged in the last few decades with the integration of…

  8. Using Analogies as an Experiential Learning Technique in Multicultural Education

    Science.gov (United States)

    Suthakaran, V.; Filsinger, Keri; White, Brittany

    2013-01-01

    In this article the authors specifically address the use of narratives in the form of analogies as an experiential learning activity. The use of analogies as an experiential learning tool in multicultural education can be helpful in a number of ways. Analogies provide an alternative tool for processing multicultural topics with students who have…

  9. Josephson junction analog and quasiparticle-pair current

    DEFF Research Database (Denmark)

    Bak, Christen Kjeldahl; Pedersen, Niels Falsig

    1973-01-01

    A close analogy exists between a Josephson junction and a phase-locked loop. A new type of electrical analog based on this principle is presented. It is shown that the inclusion in this analog of a low-pass filter gives rise to a current of the same form as the Josephson quasiparticle-pair current...

  10. Analogical Instruction in Statistics: Implications for Social Work Educators

    Science.gov (United States)

    Thomas, Leela

    2008-01-01

    This paper examines the use of analogies in statistics instruction. Much has been written about the difficulty social work students have with statistics. To address this concern, Glisson and Fischer (1987) called for the use of analogies. Understanding of analogical problem solving has surged in the last few decades with the integration of…

  11. High-Speed, High-Resolution Analog Waveform Sampling in VLSI Technology

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Gunther

    1998-10-13

    Switched-capacitor analog memories are well-suited to a number of applications where a continuous digitization of analog signals is not needed. In data acquisition systems based on the use of an analog memory, the input waveforms are sampled and stored at a high rate for a limited period of time, and the analog samples are then retrieved at a lower rate and digitized with a slow ADC before new waveforms are acquired. The advantages of using an analog memory are lower overall power dissipation and cost, higher density and reliability, and potentially superior performance. The analog memory essentially exploits the fact that the sampling and storage of samples in a bank of analog memory cells can be accomplished at a higher rate and with a greater precision than direct digital conversion. This dissertation examines the important components of an analog memory in detail and investigates their use in a number of architectures. The research has led to the design of an analog memory that can acquire analog waveforms at sampling rates of several hundred MHz with a dynamic range and linearity of more than 12 bits, without the need for elaborate calibration and correction procedures. This is accomplished by means of a new memory architecture that results in memory cell pedestals and sampling times that are independent of the signal level, as well as cell gains that are insensitive to component sizes. The write address control for this memory has been realized with an inverter delay chain that provides substantially higher performance with respect to sampling rate and timing accuracy than other published approaches. Based upon the concepts developed in this work, an experimental analog memory was designed and integrated in a 2-{mu}m CMOS process. Extensive measurements of this prototype at sampling rates up to 700MHz are presented and demonstrate a dynamic range, linearity, offset, and gain accuracy corresponding to a precision of more than 12bits after a simple dc baseline

  12. Glycolaldehyde in Perseus young solar analogs

    Science.gov (United States)

    De Simone, M.; Codella, C.; Testi, L.; Belloche, A.; Maury, A. J.; Anderl, S.; André, Ph.; Maret, S.; Podio, L.

    2017-03-01

    Context. The earliest evolutionary stages of low-mass protostars are characterised by the so-called hot-corino stage, when the newly born star heats the surrounding material and enrich the gas chemically. Studying this evolutionary phase of solar protostars may help understand the evolution of prebiotic complex molecules in the development of planetary systems. Aims: In this paper we focus on the occurrence of glycolaldehyde (HCOCH2OH) in young solar analogs by performing the first homogeneous and unbiased study of this molecule in the Class 0 protostars of the nearby Perseus star forming region. Methods: We obtained sub-arcsec angular resolution maps at 1.3 mm and 1.4 mm of glycolaldehyde emission lines using the IRAM Plateau de Bure (PdB) interferometer in the framework of the CALYPSO IRAM large program. Results: Glycolaldehyde has been detected towards 3 Class 0 and 1 Class I protostars out of the 13 continuum sources targeted in Perseus: NGC 1333-IRAS2A1, NGC 1333-IRAS4A2, NGC 1333-IRAS4B1, and SVS13-A. The NGC 1333 star forming region looks particularly glycolaldehyde rich, with a rate of occurrence up to 60%. The glycolaldehyde spatial distribution overlaps with the continuum one, tracing the inner 100 au around the protostar. A large number of lines (up to 18), with upper-level energies Eu from 37 K up to 375 K has been detected. We derived column densities ≥1015 cm-2 and rotational temperatures Trot between 115 K and 236 K, imaging for the first time hot-corinos around NGC 1333-IRAS4B1 and SVS13-A. Conclusions: In multiple systems glycolaldehyde emission is detected only in one component. The case of the SVS13-A+B and IRAS4-A1+A2 systems support that the detection of glycolaldehyde (at least in the present Perseus sample) indicates older protostars (i.e. SVS13-A and IRAS4-A2), evolved enough to develop the hot-corino region (i.e. 100 K in the inner 100 au). However, only two systems do not allow us to firmly conclude whether the primary factor leading to

  13. Categories children find easy and difficult to process in figural analogies

    Directory of Open Access Journals (Sweden)

    Claire E Stevenson

    2014-08-01

    Full Text Available Analogical reasoning, the ability to learn about novel phenomena by relating it to structurally similar knowledge, develops with great variability in children. Furthermore, the development of analogical reasoning coincides with greater working memory efficiency and increasing knowledge of the objects and rules present in analogy problems. In figural matrices, a classical form of analogical reasoning assessment, some categories, such as color, appear easier for children to encode and infer than others, such as orientation. Yet, few studies have structurally examined differences in the difficulty of rule-types across different age-groups. This cross-sectional study of figural analogical reasoning examined which underlying rules in figural analogies were easier or more difficult for children to correctly process. School children (N=1422, M=7.0 years, SD=21 months, range 4.5-12.5 years were assessed in analogical reasoning using classical figural matrices and memory measures. The transformations the children had to induce and apply concerned the categories: animal, color, orientation, position, quantity and size. The role of age and memory span on the children’s ability to correctly process each type of transformation was examined using explanatory item response theory models. The results showed that with increasing age and/or greater memory span all transformations were processed more accurately. The what transformations animal, color, quantity and size were easiest, whereas the where transformations orientation and position were most difficult. However, animal, orientation and position became relatively easier with age and increased memory efficiency. The implications are discussed in terms of the development of visual processing in object recognition versus position and motion encoding, the ventral (what and dorsal (where pathways respectively.

  14. Visual relations children find easy and difficult to process in figural analogies

    Science.gov (United States)

    Stevenson, Claire E.; Alberto, Rosa A.; van den Boom, Max A.; de Boeck, Paul A. L.

    2014-01-01

    Analogical reasoning, the ability to learn about novel phenomena by relating it to structurally similar knowledge, develops with great variability in children. Furthermore, the development of analogical reasoning coincides with greater working memory efficiency and increasing knowledge of the entities and relations present in analogy problems. In figural matrices, a classical form of analogical reasoning assessment, some features, such as color, appear easier for children to encode and infer than others, such as orientation. Yet, few studies have structurally examined differences in the difficulty of visual relations across different age-groups. This cross-sectional study of figural analogical reasoning examined which underlying rules in figural analogies were easier or more difficult for children to correctly process. School children (N = 1422, M = 7.0 years, SD = 21 months, range 4.5–12.5 years) were assessed in analogical reasoning using classical figural matrices and memory measures. The visual relations the children had to induce and apply concerned the features: animal, color, orientation, position, quantity and size. The role of age and memory span on the children's ability to correctly process each type of relation was examined using explanatory item response theory models. The results showed that with increasing age and/or greater memory span all visual relations were processed more accurately. The “what” visual relations animal, color, quantity and size were easiest, whereas the “where” relations orientation and position were most difficult. However, the “where” visual relations became relatively easier with age and increased memory efficiency. The implications are discussed in terms of the development of visual processing in object recognition vs. position and motion encoding in the ventral (“what”) and dorsal (“where”) pathways respectively. PMID:25140160

  15. Multimode lasers as analogs of complex biological systems (a survey)

    Science.gov (United States)

    Danilov, O. B.; Rosanov, N. N.; Solov'ev, N. A.; Soms, L. N.

    2016-04-01

    Simulating the activity of complex biological systems, in particular, the human brain, is a topical problem the solution of which is necessary both for understanding their functioning and for developing new classes of computational system based on operating principles of the brain. Some features and analogies that can be found in the operation of laser systems and brain and used for developing new generation computational systems are discussed. The appropriateness of such analogies is justified by the fact that both laser systems and the brain are open (interacting with the environment) dissipative spatially distributed nonlinear systems. Therefore, laser optical systems and, in particular, systems with dissipative optical solitons offer an opportunity to experimentally and theoretically model some important cognitive brain functions. One of particularities of the brain operation is the ability to manipulate images. Proceeding from this, in this work, problems related to generation and amplification with laser of spatial structures (images), as well as to amplification of signals coming to it from outside are discussed.

  16. Military Importance of Natural Toxins and Their Analogs.

    Science.gov (United States)

    Pitschmann, Vladimír; Hon, Zdeněk

    2016-04-28

    Toxin weapon research, development, production and the ban on its uses is an integral part of international law, with particular attention paid to the protection against these weapons. In spite of this, hazards associated with toxins cannot be completely excluded. Some of these hazards are also pointed out in the present review. The article deals with the characteristics and properties of natural toxins and synthetic analogs potentially constituting the basis of toxin weapons. It briefly describes the history of military research and the use of toxins from distant history up to the present age. With respect to effective disarmament conventions, it mentions certain contemporary concepts of possible toxin applications for military purposes and the protection of public order (suppression of riots); it also briefly refers to the question of terrorism. In addition, it deals with certain traditional as well as modern technologies of the research, synthesis, and use of toxins, which can affect the continuing development of toxin weapons. These are, for example, cases of new toxins from natural sources, their chemical synthesis, production of synthetic analogs, the possibility of using methods of genetic engineering and modern biotechnologies or the possible applications of nanotechnology and certain pharmaceutical methods for the effective transfer of toxins into the organism. The authors evaluate the military importance of toxins based on their comparison with traditional chemical warfare agents. They appeal to the ethics of the scientific work as a principal condition for the prevention of toxin abuse in wars, military conflicts, as well as in non-military attacks.

  17. Principles for Integrating Mars Analog Science, Operations, and Technology Research

    Science.gov (United States)

    Clancey, William J.

    2003-01-01

    During the Apollo program, the scientific community and NASA used terrestrial analog sites for understanding planetary features and for training astronauts to be scientists. Human factors studies (Harrison, Clearwater, & McKay 1991; Stuster 1996) have focused on the effects of isolation in extreme environments. More recently, with the advent of wireless computing, we have prototyped advanced EVA technologies for navigation, scheduling, and science data logging (Clancey 2002b; Clancey et al., in press). Combining these interests in a single expedition enables tremendous synergy and authenticity, as pioneered by Pascal Lee's Haughton-Mars Project (Lee 2001; Clancey 2000a) and the Mars Society s research stations on a crater rim on Devon Island in the High Canadian Arctic (Clancey 2000b; 2001b) and the Morrison Formation of southeast Utah (Clancey 2002a). Based on this experience, the following principles are proposed for conducting an integrated science, operations, and technology research program at analog sites: 1) Authentic work; 2) PI-based projects; 3) Unencumbered baseline studies; 4) Closed simulations; and 5) Observation and documentation. Following these principles, we have been integrating field science, operations research, and technology development at analog sites on Devon Island and in Utah over the past five years. Analytic methods include work practice simulation (Clancey 2002c; Sierhuis et a]., 2000a;b), by which the interaction of human behavior, facilities, geography, tools, and procedures are formalized in computer models. These models are then converted into the runtime EVA system we call mobile agents (Clancey 2002b; Clancey et al., in press). Furthermore, we have found that the Apollo Lunar Surface Journal (Jones, 1999) provides a vast repository or understanding astronaut and CapCom interactions, serving as a baseline for Mars operations and quickly highlighting opportunities for computer automation (Clancey, in press).

  18. Light scattering by planetary-regolith analog samples: computational results

    Science.gov (United States)

    Väisänen, Timo; Markkanen, Johannes; Hadamcik, Edith; Levasseur-Regourd, Anny-Chantal; Lasue, Jeremie; Blum, Jürgen; Penttilä, Antti; Muinonen, Karri

    2017-04-01

    We compute light scattering by a planetary-regolith analog surface. The corresponding experimental work is from Hadamcik et al. [1] with the PROGRA2-surf [2] device measuring the polarization of dust particles. The analog samples are low density (volume fraction 0.15 ± 0.03) agglomerates produced by random ballistic deposition of almost equisized silica spheres (refractive index n=1.5 and diameter 1.45 ± 0.06 µm). Computations are carried out with the recently developed codes entitled Radiative Transfer with Reciprocal Transactions (R2T2) and Radiative Transfer Coherent Backscattering with incoherent interactions (RT-CB-ic). Both codes incorporate the so-called incoherent treatment which enhances the applicability of the radiative transfer as shown by Muinonen et al. [3]. As a preliminary result, we have computed scattering from a large spherical medium with the RT-CB-ic using equal-sized particles with diameters of 1.45 microns. The preliminary results have shown that the qualitative characteristics are similar for the computed and measured intensity and polarization curves but that there are still deviations between the characteristics. We plan to remove the deviations by incorporating a size distribution of particles (1.45 ± 0.02 microns) and detailed information about the volume density profile within the analog surface. Acknowledgments: We acknowledge the ERC Advanced Grant no. 320773 entitled Scattering and Absorption of Electromagnetic Waves in Particulate Media (SAEMPL). Computational resources were provided by CSC - IT Centre for Science Ltd, Finland. References: [1] Hadamcik E. et al. (2007), JQSRT, 106, 74-89 [2] Levasseur-Regourd A.C. et al. (2015), Polarimetry of stars and planetary systems, CUP, 61-80 [3] Muinonen K. et al. (2016), extended abstract for EMTS.

  19. Influences of Stocking Salmon Carcass Analogs on Salmonids in Klickitat River Tributaries, 2001-2005 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Zendt, Joe; Sharp, Bill (Yakama Nation Fisheries, Toppenish, WA)

    2006-09-01

    This report describes the work completed by the Yakama Nation Fisheries Program (YNFP) in the Klickitat subbasin in south-central Washington under BPA innovative project No.200105500--Influences of stocking salmon carcass analogs on salmonids in Columbia River Tributaries. Salmon carcasses historically provided a significant source of marine-derived nutrients to many stream systems in the Columbia basin, and decreased run sizes have led to a loss of this nutrient source in many streams. Partners in this project developed a pathogen-free carcass analog and stocked the analogs in streams with the following objectives: restoring food availability to streams with reduced anadromous salmon returns; mimicking the natural pathways and timing of food acquisition by salmonids; minimizing unintended negative ecological effects; and increasing the growth and survival of salmonids. In the Klickitat subbasin, carcass analogs were stocked in two streams in 2002 and 2003; a third stream was used as a control. Salmonid fish abundance, growth, and stomach contents were monitored in all three streams before and after carcass analog placement. Fish, invertebrate, and periphyton samples were also collected for stable isotope analysis (to determine if nutrients from carcass analogs were incorporated into the stream food web). Water quality samples were also collected to determine if nutrient overloading occurred in streams. Significant differences in growth were found between fish in treated and untreated stream reaches. Fish in treatment reaches exhibited higher instantaneous growth rates approximately one month after the first carcass analog stocking. Stomach contents sampling indicated that salmonid fish routinely consumed the carcass analog material directly, and that stomach fullness of fish in treatment reaches was higher than in untreated reaches in the first few weeks following carcass analog stockings. No significant differences were detected in fish abundance between

  20. Influences of Stocking Salmon Carcass Analogs on Salmonids in Klickitat River Tributaries, 2001-2005 Completion Report.

    Energy Technology Data Exchange (ETDEWEB)

    Zendt, Joe; Sharp, Bill (Yakama Nation Fisheries, Toppenish, WA)

    2006-09-01

    This report describes the work completed by the Yakama Nation Fisheries Program (YNFP) in the Klickitat subbasin in south-central Washington under BPA innovative project No.200105500--Influences of stocking salmon carcass analogs on salmonids in Columbia River Tributaries. Salmon carcasses historically provided a significant source of marine-derived nutrients to many stream systems in the Columbia basin, and decreased run sizes have led to a loss of this nutrient source in many streams. Partners in this project developed a pathogen-free carcass analog and stocked the analogs in streams with the following objectives: restoring food availability to streams with reduced anadromous salmon returns; mimicking the natural pathways and timing of food acquisition by salmonids; minimizing unintended negative ecological effects; and increasing the growth and survival of salmonids. In the Klickitat subbasin, carcass analogs were stocked in two streams in 2002 and 2003; a third stream was used as a control. Salmonid fish abundance, growth, and stomach contents were monitored in all three streams before and after carcass analog placement. Fish, invertebrate, and periphyton samples were also collected for stable isotope analysis (to determine if nutrients from carcass analogs were incorporated into the stream food web). Water quality samples were also collected to determine if nutrient overloading occurred in streams. Significant differences in growth were found between fish in treated and untreated stream reaches. Fish in treatment reaches exhibited higher instantaneous growth rates approximately one month after the first carcass analog stocking. Stomach contents sampling indicated that salmonid fish routinely consumed the carcass analog material directly, and that stomach fullness of fish in treatment reaches was higher than in untreated reaches in the first few weeks following carcass analog stockings. No significant differences were detected in fish abundance between

  1. Inviting Argument by Analogy: Analogical-Mapping-Based Comparison Activities as a Scaffold for Small-Group Argumentation

    Science.gov (United States)

    Emig, Brandon R.; McDonald, Scott; Zembal-Saul, Carla; Strauss, Susan G.

    2014-01-01

    This study invited small groups to make several arguments by analogy about simple machines. Groups were first provided training on analogical (structure) mapping and were then invited to use analogical mapping as a scaffold to make arguments. In making these arguments, groups were asked to consider three simple machines: two machines that they had…

  2. A possible analogy between contours in mathematics--as exemplified by Cauchy's integral formula--and contours in the arts.

    Science.gov (United States)

    Gerr, S

    1982-01-01

    An attempt is made to draw an analogy between contour drawing and a particular mathematical theorem. The analogy is seen to depend on the fact that both methods use definite values along a contour to imply a totality of values within the contour; thus, the use of a part to suggest the whole, by way of a hypothetical 'gestalt-like integration' in the case of the art contour, and the usual process of mathematical integration in the case of Cauchy's formula. Examples illustrating the analogy are drawn from a wide range of artistic work: a modern American drawing, a Cro-Magnon cave painting, and two Chinese works. The traditional Chinese philosophy of painting is invoked in support of the analogy because of its explicit emphasis on the primacy of outline drawing in Chinese painting. Some speculations are offered on further development and application of the analogy.

  3. Analog Modeling of Continental Lithosphere Subduction

    Science.gov (United States)

    Willingshofer, E.; Sokoutis, D.; Luth, S.; Beekman, F.; Cloetingh, S.

    2012-12-01

    Lithospheric-scale analog modeling sheds light on the consequences of decoupling within the continental lithosphere and along plate interfaces during continental collision. The model results provide valuable information in terms of strain localization, deformation of the subducting slab and the evolution and architecture of the overlying mountain belt and its topography. A weak layer has been implemented in three-layer models to simulate decoupling along the plate interface and at different levels of the lithosphere (brittle-ductile transition, entire lower crust, crust-mantle boundary). Additionally, varying the strength of the mantle lithosphere of both the upper as well as the lower plate regulated the degree of plate coupling. Plate boundaries were orthogonal to the convergence direction. All models emphasize that strong decoupling at the plate interface is a pre-requisite for the subduction of continental lithosphere. In addition, deformation of the subducting slab was found to be sensitive to the strength contrast between the subduction zone and the mantle lithosphere of the downgoing as well as the upper plate. As such, a low strength contrast between the plate interface and the lower plate leads to deformation of the subducting slab by thickening and the development of a shallow slab. Conversely, when the strength contrast is high, deep slabs evolve which undergo relatively less deformation. Furthermore, the level of decoupling in the downgoing plate governs how much continental crust is subducted together with the mantle lithosphere. Shallow decoupling, at the brittle-ductile transition, results in subduction of the lower crust whereas small amounts of lower crust are subducted when decoupling occurs at the level of the Moho. Weak plate coupling and a weak lower crust of the lower plate steer the evolution of mountain belts such that deformation propagates outward, in the direction of the incoming plate, by successive imbrication of upper crustal thrust

  4. Enzymatically stable 5' mRNA cap analogs: synthesis and binding studies with human DcpS decapping enzyme.

    Science.gov (United States)

    Kalek, Marcin; Jemielity, Jacek; Darzynkiewicz, Zbigniew M; Bojarska, Elzbieta; Stepinski, Janusz; Stolarski, Ryszard; Davis, Richard E; Darzynkiewicz, Edward

    2006-05-01

    Four novel 5' mRNA cap analogs have been synthesized with one of the pyrophosphate bridge oxygen atoms of the triphosphate linkage replaced with a methylene group. The analogs were prepared via reaction of nucleoside phosphor/phosphon-1-imidazolidates with nucleoside phosphate/phosphonate in the presence of ZnCl2. Three of the new cap analogs are completely resistant to degradation by human DcpS, the enzyme responsible for hydrolysis of free cap resulting from 3' to 5' cellular mRNA decay. One of the new analogs has very high affinity for binding to human DcpS. Two of these analogs are Anti Reverse Cap Analogs which ensures that they are incorporated into mRNA chains exclusively in the correct orientation. These new cap analogs should be useful in a variety of biochemical studies, in the analysis of the cellular function of decapping enzymes, and as a basis for further development of modified cap analogs as potential anti-cancer and anti-parasite drugs.

  5. Three optimized and validated (using accuracy profiles) LC methods for the determination of pentamidine and new analogs in rat plasma.

    Science.gov (United States)

    Hambÿe, S; Stanicki, D; Colet, J-M; Aliouat, E M; Vanden Eynde, J J; Blankert, B

    2011-01-15

    Three novel LC-UV methods for the determination of pentamidine (PTMD) and two of its new analogs in rat plasma are described. The chromatographic conditions (wavelength, acetonitrile percentage in the mobile phase, internal standard) were optimized to have an efficient selectivity. A pre-step of extraction was simultaneously developed for each compound. For PTMD, a solid phase extraction (SPE) with Oasis(®) HLB cartridges was selected, while for the analogs we used protein precipitation with acetonitrile. SPE for PTMD gave excellent results in terms of extraction yield (99.7 ± 2.8) whereas the recoveries for the analogs were not so high but were reproducible as well (64.6 ± 2.6 and 36.8 ± 1.6 for analog 1 and 2, respectively). By means of a recent strategy based on accuracy profiles (β-expectation tolerance interval), the methods were successfully validated. β was fixed at 95% and the acceptability limits at ± 15% as recommended by the FDA. The method was successfully validated for PTMD (29.6-586.54 ng/mL), analog 1 (74.23-742.3 ng/mL) and analog 2 (178.12-890.6 ng/mL). The first concentration level tested was considered as the LLOQ (lower limit of quantification) for PTMD and analog 1 whereas for analog 2, the LLOQ was not the first level tested and was raised to 178.12 ng/mL.

  6. Strategy for identifying natural analogs of the long-term performance of low-level waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Chatters, J.C.; Waugh, W.J.; Foley, M.G.; Kincaid, C.T.

    1990-07-01

    The US Department of Energy's Low-Level Waste (LLW) Management Program has asked Pacific Northwest Laboratory (PNL) to explore the feasibility of using natural analogs of anticipated waste site and conditions to help validate predictions of the performance of LLW disposal sites. Current regulations require LLW facilities to control the spread of hazardous substances into the environment for at least the next 500 years. Natural analog studies can provide information about processes affecting waste containment that cannot be fully explored through laboratory experimentation and modeling because of the extended period of required performance. For LLW applications, natural analogs include geochemical systems, pedogenic (soil formation) indicators, proxy climate data, and ecological and archaeological settings that portray long-term changes in disposal site environments and the survivability of proposed waste containment materials and structures. Analog data consist of estimates of performance assessment (PA) model input parameters that define possible future environmental states of waste sites, validation parameters that can be predicted by PA models, and descriptive information that can build public confidence in waste disposal practices. This document describes PNL's overall stategy for identifying analogs for LLW disposal systems, reviews lessons learned from past analogs work, outlines the findings of the workshop, and presents examples of analog studies that workshop participants found to be applicable to LLW performance assessment. The lessons from the high-level waste analogs experience and workshop discussions will be used to develop detailed study plans during FY 1990. 39 refs.

  7. Analogic China map constructed by DNA

    Institute of Scientific and Technical Information of China (English)

    QIAN Lulu; HE Lin; WANG Ying; ZHANG Zhao; ZHAO Jian; PAN Dun; ZHANG Yi; LIU Qiang; FAN Chunhai; HU Jun

    2006-01-01

    In this research, a nanoscale DNA structure of analogic China map is created. The nanostructure of roughly 150 nm in diameter with a spatial resolution of 6 nm is purely constructed by folding DNA. The picture observed by atomic force microscopy (AFM) is almost identical with the designed shape. The DNA origami technology invented by Rothemund in 2006 is employed in the construction of this shape, which has proved the capability of constructing almost any complicated shape enabled by DNA origami, and provides new bottom-up method for constructing nanostructures.

  8. Analogy among microfluidics, micromechanics, and microelectronics.

    Science.gov (United States)

    Li, Sheng-Shian; Cheng, Chao-Min

    2013-10-07

    We wish to illuminate the analogous link between microfluidic-based devices, and the already established pairing of micromechanics and microelectronics to create a triangular/three-way scientific relationship as a means of interlinking familial disciplines and accomplishing two primary goals: (1) to facilitate the modeling of multidisciplinary domains; and, (2) to enable us to co-simulate the entire system within a compact circuit simulator (e.g., Cadence or SPICE). A microfluidic channel-like structure embedded in a micro-electro-mechanical resonator via our proposed CMOS-MEMS technology is used to illustrate the connections among microfluidics, micromechanics, and microelectronics.

  9. Reconfiguration of Analog Electronics for Extreme Environments

    Science.gov (United States)

    Stoica, Adrian; Zebulum, Ricardo; Keymeulen, Didier; Guo, Xin

    2005-01-01

    This paper argues in favor of adaptive reconfiguration as a technique to expand the operational envelope of analog electronics for extreme environments (EE). On a reconfigurable device, although component parameters change in EE, as long as devices still operate, albeit degraded, a new circuit design, suitable for new parameter values, may be mapped into the reconfigurable structure to recover the initial circuit function. Laboratory demonstrations of this technique were performed by JPL in several independent experiments in which bulk CMOS reconfgurable devices were exposed to, and degraded by, high temperatures (approx.300 C) or radiation (300kRad TID), and then recovered by adaptive reconfiguration using evolutionary search algorithms.

  10. An Analog VLSI Saccadic Eye Movement System

    OpenAIRE

    1994-01-01

    In an effort to understand saccadic eye movements and their relation to visual attention and other forms of eye movements, we - in collaboration with a number of other laboratories - are carrying out a large-scale effort to design and build a complete primate oculomotor system using analog CMOS VLSI technology. Using this technology, a low power, compact, multi-chip system has been built which works in real-time using real-world visual inputs. We describe in this paper the performance of a...

  11. Integrated Analogic Filter Tuning System Design

    Directory of Open Access Journals (Sweden)

    Karolis Kiela

    2016-06-01

    Full Text Available Parameters of integrated analog filters can vary due to temperatu-re change, IC process variation and therefore they should have dedicated tuning circuits that compensate these imperfections. A method is proposed that speeds up switched resistor bank design while taking into account the required tuning range and step size. A novel counter structure is used in the tuning circuit that is ba-sed on successive approximation approach. The proposed swit-ched resistor design method and tuning circuit are designed in 0.18 μm CMOS technology and verified. Results are compared to existing tuning circuit designs.

  12. Design of analog circuits through symbolic analysis

    CERN Document Server

    Fakhfakh, Mourad; V Fernández, Francisco

    2012-01-01

    Symbolic analyzers have the potential to offer knowledge to sophomores as well as practitioners of analog circuit design. Actually, they are an essential complement to numerical simulators, since they provide insight into circuit behavior which numerical analyzers do not provide. Symbolic analysis of electronic circuits addresses the generation of symbolic expressions for the parameters that describe the performance of linear and nonlinear circuits in three domains: DC, AC and time; some or all the circuit parameters can be kept as symbols. Due to the fact that these expressions remain va

  13. An optical analog of quantum optomechanics

    CERN Document Server

    Rodríguez-Lara, B M

    2014-01-01

    We present a two-dimensional array of nearest-neighbor coupled waveguides that is the optical analog of a quantum optomechanical system. We show that the quantum model predicts the appearance of effective column isolation, diagonal-coupling and other non-trivial couplings in the two-dimensional photonic lattice under a standard approximation from ion-trap cavity electrodynamics. We provide an approximate impulse function for the case of effective column isolation and compare it with exact numerical propagation in the photonic lattice.

  14. Analogies as categorization phenomena: Studies from scientific discourse

    Science.gov (United States)

    Atkins, Leslie Jill

    Studies on the role of analogies in science classrooms have tended to focus on analogies that come from the teacher or curriculum, and not the analogies that students generate. Such studies are derivative of an educational system that values content knowledge over scientific creativity, and derivative of a model of teaching in which the teacher's role is to convey content knowledge. This dissertation begins with the contention that science classrooms should encourage scientific thinking and one role of the teacher is to model that behavior and identify and encourage it in her students. One element of scientific thinking is analogy. This dissertation focuses on student-generated analogies in science, and offers a model for understanding these. I provide evidence that generated analogies are assertions of categorization, and the base of an analogy is the constructed prototype of an ad hoc category. Drawing from research on categorization, I argue that generated analogies are based in schemas and cognitive models. This model allows for a clear distinction between analogy and literal similarity; prior to this research analogy has been considered to exist on a spectrum of similarity, differing from literal similarity to the degree that structural relations hold but features do not. I argue for a definition in which generated analogies are an assertion of an unexpected categorization: that is, they are asserted as contradictions to an expected schema.

  15. Analogy perception applied to seven tests of word comprehension

    CERN Document Server

    Turney, Peter D

    2011-01-01

    It has been argued that analogy is the core of cognition. In AI research, algorithms for analogy are often limited by the need for hand-coded high-level representations as input. An alternative approach is to use high-level perception, in which high-level representations are automatically generated from raw data. Analogy perception is the process of recognizing analogies using high-level perception. We present PairClass, an algorithm for analogy perception that recognizes lexical proportional analogies using representations that are automatically generated from a large corpus of raw textual data. A proportional analogy is an analogy of the form A:B::C:D, meaning "A is to B as C is to D". A lexical proportional analogy is a proportional analogy with words, such as carpenter:wood::mason:stone. PairClass represents the semantic relations between two words using a high-dimensional feature vector, in which the elements are based on frequencies of patterns in the corpus. PairClass recognizes analogies by applying s...

  16. Analogies in medicine: valuable for learning, reasoning, remembering and naming.

    Science.gov (United States)

    Pena, Gil Patrus; Andrade-Filho, José de Souza

    2010-10-01

    Analogies are important tools in human reasoning and learning, for resolving problems and providing arguments, and are extensively used in medicine. Analogy and similarity involve a structural alignment or mapping between domains. This cognitive mechanism can be used to make inferences and learn new abstractions. Through analogies, we try to explain a knowledge to be achieved (the target), with pieces of information already familiar to the learner (the source), keeping in mind the constraints of similarity, structure and purpose. The purpose of this essay is to examine the use of analogies in medicine. We provide a brief review of the theoretical basis of analogical reasoning. This theoretical background is discussed in the light of actual examples of analogies retrieved from medical literature. In medicine, analogies have long been used to explain several physiologic and pathologic processes. Besides deeper structural relations, superficial attribute similarity is extensively used in many medical specialties. These attribute similarities are important in naming, categorizing and classifying, and play a role as learning and memorizing tools. Analogies also serve as basis for medical nomenclature. The choice of the source of analogies is highly dependent on cultural background, and may derive from ancient or diverse cultures. Learning by analogies may thus require research on culture diversity in order to establish an adequate justification and to comprehend the purpose of an analogy.

  17. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Science.gov (United States)

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Influences of Stocking Salmon Carcass Analogs on Salmonids in Yakima River Tributaries, 2001-2002 Technical Report.

    Energy Technology Data Exchange (ETDEWEB)

    Pearsons, Todd N.; Johnson, Christopher L. (Washington Department of Fish and Wildlife, Olympia, WA)

    2003-04-01

    The benefits that marine derived nutrients from adult salmon carcasses provide to juvenile salmonids are increasingly being recognized. Current estimates suggest that only 6-7% of marine-derived nitrogen and phosphorus that were historically available to salmonids in the Pacific Northwest are currently available. Food limitation may be a major constraint limiting the restoration of salmonids. A variety of methods have been proposed to offset this nutrient deficit including: allowing greater salmon spawning escapement, stocking hatchery salmon carcasses, and stocking inorganic nutrients. Unfortunately, each of these methods has some ecological or socio-economic shortcoming. We intend to overcome many of these shortcomings by making and evaluating a pathogen free product that simulates a salmon carcass (analog). Abundant sources of marine derived nutrients are available such as fish offal from commercial fishing and salmon carcasses from hatcheries. However, a method for recycling these nutrients into a pathogen free analog that degrades at a similar rate as a natural salmon carcass has never been developed. We endeavored to (1) develop a salmon carcass analog that will increase the food available to salmonids, (2) determine the pathways that salmonids use to acquire food from analogs, and (3) determine the benefits to salmonids and the potential for application to salmonid restoration. We used a before-after-control-impact-paired design in six tributaries of the upper Yakima basin to determine the utility of stocking carcass analogs. Our preliminary results suggest that the introduction of carcass analogs into food-limited streams can be used to restore food pathways previously provided by anadromous salmon. The analogs probably reproduced both of the major food pathways that salmon carcasses produce: direct consumption and food chain enhancement. Trout and salmon fed directly on the carcass analogs during the late summer and presumably benefited from the increased

  19. Use of analogy in learning physics: The role of representations

    Directory of Open Access Journals (Sweden)

    Noah D. Finkelstein

    2006-07-01

    Full Text Available Previous studies have demonstrated that analogies can promote student learning in physics and can be productively taught to students to support their learning, under certain conditions. We build on these studies to explore the use of analogy by students in a large introductory college physics course. In the first large-scale study of its kind, we demonstrate that different analogies can lead to varied student reasoning. When different analogies were used to teach electromagnetic (EM waves, we found that students explicitly mapped characteristics either of waves on strings or sound waves to EM waves, depending upon which analogy students were taught. We extend these results by investigating how students use analogies. Our findings suggest that representational format plays a key role in the use of analogy.

  20. Continuous-time analog filter in CMOS nanoscale era

    Science.gov (United States)

    Baschirotto, A.; De Matteis, M.; Pezzotta, A.; D'Amico, S.

    2014-04-01

    Analog filters are key blocks in analog signal processing. They are widely employed in many systems, like wireless transceivers, detectors read-out, sensors interfaces, etc. The IC technology choice for such systems is mainly dictated by the requirements of high speed and low power consumption of digital circuits. This pushed an impressive movement towards scaled technology and this has important consequences on the analog circuits design. The impact of technology scaling down to nanometre scale on analog filters design is here investigated. For instance, supply voltage reduction in analog filters limits circuits design solutions and could result in higher power consumption. Moreover, at the same time, innovative systems push analog filters to get higher and higher operation frequencies, due to the increasing bandwidth/speed requirements. Recent solutions for efficient low-voltage and high frequency analog filters in nanometre technology are described.

  1. Antarctic Analog for Dilational Bands on Europa

    Science.gov (United States)

    Hurford, T. A.; Brunt, K. M.

    2014-01-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  2. AFEII Analog Front End Board Design Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Rubinov, Paul; /Fermilab

    2005-04-01

    This document describes the design of the 2nd iteration of the Analog Front End Board (AFEII), which has the function of receiving charge signals from the Central Fiber Tracker (CFT) and providing digital hit pattern and charge amplitude information from those charge signals. This second iteration is intended to address limitations of the current AFE (referred to as AFEI in this document). These limitations become increasingly deleterious to the performance of the Central Fiber Tracker as instantaneous luminosity increases. The limitations are inherent in the design of the key front end chips on the AFEI board (the SVXIIe and the SIFT) and the architecture of the board itself. The key limitations of the AFEI are: (1) SVX saturation; (2) Discriminator to analog readout cross talk; (3) Tick to tick pedestal variation; and (4) Channel to channel pedestal variation. The new version of the AFE board, AFEII, addresses these limitations by use of a new chip, the TriP-t and by architectural changes, while retaining the well understood and desirable features of the AFEI board.

  3. Isolation and characterization of soybean NBS analogs

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Isolation of plant resistance genes is greatly helpful to crop resistance breeding and the insight of resistance mechanism. The cloned plant resistance genes are classified into four classes according to their putative structural domain, of which the majority possesses nucleotide-binding site (NBS) domain that consists of P-loop, kinase2a and kinase3a. The conservation of this domain affords the potential possibility of cloning the plant resistance genes, which is homology-based cloning technique. In the present study, the degenerate oligonucleotide primers were designed according to the tobacco N and Arabidopsis RPS2, and 358 clones were isolated from the genomic DNA of resistance soybean cultivar Kefeng1, resistant to soybean mosaic virus, and 4 open-reading NBS analogs were finally characterized and designated as KNBS1, KNBS2, KNBS3 and KNBS4. Southern hybridization suggested that they were present with multicopy in the soybean genome; KNBS4 was mapped to F linkage group and KNBS2 co-located J linkage group with the SCAR marker of Rsa resistant to soybean mosaic virus by RFLP analysis. Northern analysis suggested that KNBS2- related sequence was low and constitutively expressed in the root, stem and leaves of soybean. The detailed characterization of NBS analogs is very helpful to ultimately cloning the soybean resistance gene.

  4. The exoplanets analogy to the Multiverse

    CERN Document Server

    Kinouchi, Osame

    2015-01-01

    The idea of a Mutiverse is controversial, although it is a natural possible solution to particle physics and cosmological fine-tuning problems (FTPs). Here I explore the analogy between the Multiverse proposal and the proposal that there exist an infinite number of stellar systems with planets in a flat Universe, the Multiplanetverse. Although the measure problem is present in this scenario, the idea of a Multiplanetverse has predictive power, even in the absence of direct evidence for exoplanets that appeared since the 90s. We argue that the fine-tuning of Earth to life (and not only the fine-tuning of life to Earth) could predict with certainty the existence of exoplanets decades or even centuries before that direct evidence. Several other predictions can be made by studying only the Earth and the Sun, without any information about stars. The analogy also shows that theories that defend that the Earth is the unique existing planet and that, at the same time, is fine-tuned to life by pure chance (or pure phy...

  5. The gravitational analog of Faraday's induction law

    Science.gov (United States)

    Zile, Daniel; Overduin, James

    2015-04-01

    Michael Faraday, the discoverer of electromagnetic induction, was convinced that there must also be a gravitational analog of this law, and he carried out drop-tower experiments in 1849 to look for the electric current induced in a coil by changes in gravitational flux through the coil. This work, now little remembered, was in some ways the first investigation of what we would now call a unified-field theory. We revisit Faraday's experiments in the light of current knowledge and ask what might be learned if they were to be performed today. We then review the gravitational analog for Faraday's law that arises within the vector (or gravito-electromagnetic) approximation to Einstein's theory of general relativity in the weak-field, low-velocity limit. This law relates spinning masses and induced ``mass currents'' rather than spinning charges and electric currents, but is otherwise remarkably similar to its electromagnetic counterpart. The predicted effects are completely unobservable in everyday settings like those envisioned by Faraday, but are thought to be relevant in astrophysical contexts like the accretion disks around collapsed stars, thus bearing out Faraday's remarkable intuition. Undergraduate student.

  6. Analog IC reliability in nanometer CMOS

    CERN Document Server

    Maricau, Elie

    2013-01-01

    This book focuses on modeling, simulation and analysis of analog circuit aging. First, all important nanometer CMOS physical effects resulting in circuit unreliability are reviewed. Then, transistor aging compact models for circuit simulation are discussed and several methods for efficient circuit reliability simulation are explained and compared. Ultimately, the impact of transistor aging on analog circuits is studied. Aging-resilient and aging-immune circuits are identified and the impact of technology scaling is discussed.   The models and simulation techniques described in the book are intended as an aid for device engineers, circuit designers and the EDA community to understand and to mitigate the impact of aging effects on nanometer CMOS ICs.   ·         Enables readers to understand long-term reliability of an integrated circuit; ·         Reviews CMOS unreliability effects, with focus on those that will emerge in future CMOS nodes; ·         Provides overview of models for...

  7. Antarctic analog for dilational bands on Europa

    Science.gov (United States)

    Hurford, T. A.; Brunt, K. M.

    2014-09-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  8. C-Glycosyl Analogs of Oligosaccharides

    Science.gov (United States)

    Vauzeilles, Boris; Urban, Dominique; Doisneau, Gilles; Beau, Jean-Marie

    This chapter covers the synthesis of a large collection of "C-oligosaccharides ", synthetic analogs of naturally occurring oligosaccharides in which a carbon atom replaces the anomeric, interglycosidic oxygen atom. These non-natural constructs are stable to chemical and enzymatic degradation, and are primarily devised to probe carbohydrate-based biological processes. These mainly target carbohydrate-protein interactions such as the modulation of glycoenzyme (glycosylhydrolases and transferases) activities or the design of ligands for lectin Carbohydrate Recognition Domains. The discussion is based on the key carbon-carbon bond assembling steps on carbohydrate templates: ionic (anionic and cationic chemistries, sigmatropic rearrangements) or radical assemblage, and olefin metathesis. Synthetic schemes in which at least one of the monosaccharide units is constructed by total synthesis or by cyclization of acyclic chiral chains are presented separately in a "partial de novo synthesis" section. The review also provides comments, when they are known, on the conformational and binding properties of these synthetic analogs, as well as their biological behavior when tested.

  9. Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

    Science.gov (United States)

    Costa, Ricardo; Bacchi, Carlos E.; Almeida Filho, Paulo

    2013-01-01

    Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET)/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU). PMID:24455330

  10. Efficient Analog Circuits for Boolean Satisfiability

    CERN Document Server

    Yin, Xunzhao; Varga, Melinda; Ercsey-Ravasz, Maria; Toroczkai, Zoltan; Hu, Xiaobo Sharon

    2016-01-01

    Efficient solutions to NP-complete problems would significantly benefit both science and industry. However, such problems are intractable on digital computers based on the von Neumann architecture, thus creating the need for alternative solutions to tackle such problems. Recently, a deterministic, continuous-time dynamical system (CTDS) was proposed (Nature Physics, 7(12), 966 (2011)) to solve a representative NP-complete problem, Boolean Satisfiability (SAT). This solver shows polynomial analog time-complexity on even the hardest benchmark $k$-SAT ($k \\geq 3$) formulas, but at an energy cost through exponentially driven auxiliary variables. With some modifications to the CTDS equations, here we present a novel analog hardware SAT solver, AC-SAT, implementing the CTDS. AC-SAT is intended to be used as a co-processor, and with its modular design can be readily extended to different problem sizes. The circuit is designed and simulated based on a 32nm CMOS technology. SPICE simulation results show speedup factor...

  11. Digital and analog gene circuits for biotechnology.

    Science.gov (United States)

    Roquet, Nathaniel; Lu, Timothy K

    2014-05-01

    Biotechnology offers the promise of valuable chemical production via microbial processing of renewable and inexpensive substrates. Thus far, static metabolic engineering strategies have enabled this field to advance industrial applications. However, the industrial scaling of statically engineered microbes inevitably creates inefficiencies due to variable conditions present in large-scale microbial cultures. Synthetic gene circuits that dynamically sense and regulate different molecules can resolve this issue by enabling cells to continuously adapt to variable conditions. These circuits also have the potential to enable next-generation production programs capable of autonomous transitioning between steps in a bioprocess. Here, we review the design and application of two main classes of dynamic gene circuits, digital and analog, for biotechnology. Within the context of these classes, we also discuss the potential benefits of digital-analog interconversion, memory, and multi-signal integration. Though synthetic gene circuits have largely been applied for cellular computation to date, we envision that utilizing them in biotechnology will enhance the efficiency and scope of biochemical production with living cells.

  12. Photonic analog-to-digital converters

    Science.gov (United States)

    Valley, George C.

    2007-03-01

    This paper reviews over 30 years of work on photonic analog-to-digital converters. The review is limited to systems in which the input is a radio-frequency (RF) signal in the electronic domain and the output is a digital version of that signal also in the electronic domain, and thus the review excludes photonic systems directed towards digitizing images or optical communication signals. The state of the art in electronic ADCs, basic properties of ADCs and properties of analog optical links, which are found in many photonic ADCs, are reviewed as background information for understanding photonic ADCs. Then four classes of photonic ADCs are reviewed: 1) photonic assisted ADC in which a photonic device is added to an electronic ADC to improve performance, 2) photonic sampling and electronic quantizing ADC, 3) electronic sampling and photonic quantizing ADC, and 4) photonic sampling and quantizing ADC. It is noted, however, that all 4 classes of “photonic ADC” require some electronic sampling and quantization. After reviewing all known photonic ADCs in the four classes, the review concludes with a discussion of the potential for photonic ADCs in the future.

  13. Metaphor and analogy in everyday problem solving.

    Science.gov (United States)

    Keefer, Lucas A; Landau, Mark J

    2016-11-01

    Early accounts of problem solving focused on the ways people represent information directly related to target problems and possible solutions. Subsequent theory and research point to the role of peripheral influences such as heuristics and bodily states. We discuss how metaphor and analogy similarly influence stages of everyday problem solving: Both processes mentally map features of a target problem onto the structure of a relatively more familiar concept. When individuals apply this structure, they use a well-known concept as a framework for reasoning about real world problems and candidate solutions. Early studies found that analogy use helped people gain insight into novel problems. More recent research on metaphor goes further to show that activating mappings has subtle, sometimes surprising effects on judgment and reasoning in everyday problem solving. These findings highlight situations in which mappings can help or hinder efforts to solve problems. WIREs Cogn Sci 2016, 7:394-405. doi: 10.1002/wcs.1407 For further resources related to this article, please visit the WIREs website.

  14. Martian hillside gullies and icelandic analogs

    Science.gov (United States)

    Hartmann, William K.; Thorsteinsson, Thorsteinn; Sigurdsson, Freysteinn

    2003-04-01

    We report observations of Icelandic hillside gully systems that are near duplicates of gullies observed on high-latitude martian hillsides. The best Icelandic analogs involve basaltic talus slopes at the angle of repose, with gully formation by debris flows initiated by ground water saturation, and/or by drainage of water from upslope cliffs. We report not only the existence of Mars analog gullies, but also an erosional sequence of morphologic forms, found both on Mars and in Iceland. The observations support hypotheses calling for creation of martian gullies by aqueous processes. Issues remain whether the water in each case comes only from surficial sources, such as melting of ground ice or snow, or from underground sources such as aquifers that gain surface access in hillsides. Iceland has many examples of the former, but the latter mechanism is not ruled out. Our observations are consistent with the martian debris flow mechanism of F. Costard et al. (2001c, Science295, 110-113), except that classic debris flows begin at midslope more frequently than on Mars. From morphologic observations, we suggest that some martian hillside gully systems not only involve significant evolution by extended erosive activity, but gully formation may occur in episodes, and the time interval since the last episode is considerably less than the time interval needed to erase the gully through normal martian obliteration processes.

  15. Palytoxin and Analogs: Biological and Ecological Effects

    Directory of Open Access Journals (Sweden)

    Vítor Ramos

    2010-06-01

    Full Text Available Palytoxin (PTX is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems.

  16. Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

    Directory of Open Access Journals (Sweden)

    Ricardo Costa

    2013-01-01

    Full Text Available Insulinoma is a rare pancreatic neuroendocrine tumor. Overproduction of insulin and associated hypoglycemia are hallmark features of this disease. Diagnosis can be made through demonstration of hypoglycemia and elevated plasma levels of insulin or C-Peptide. Metastatic disease can be detected through computerized tomography (CT scans, magnetic resonance imaging (MRI, and positron emission tomography (PET/CT. Somatostatin receptor scintigraphy can be used not only to document metastatic disease but also as a predictive marker of the benefit from therapy with radiolabeled somatostatin analog. Unresectable metastatic insulinomas may present as a major therapeutic challenge for the treating physician. When feasible, resection is the mainstay of treatment. Prevention of hypoglycemia is a crucial goal of therapy for unresectable/metastatic tumors. Diazoxide, hydrochlorothiazide, glucagon, and intravenous glucose infusions have been used for glycemic control yielding temporary and inconsistent results. Sandostatin and its long-acting depot forms have occasionally been used in the treatment of Octreoscan-positive insulinomas. Herein, we report a case of metastatic insulinoma with very difficult glycemic control successfully treated with the radiolabeled somatostatin analog lutetium (177LU.

  17. Amygdalin analogs for the treatment of psoriasis.

    Science.gov (United States)

    Perez, Juan J

    2013-05-01

    Psoriasis is one of the most prevalent immune-mediated illness worldwide. The disease can still only be managed rather than cured, so treatments are aimed at clearing skin lesions and preventing their recurrence. Several treatments are available depending on the extent of the psoriatic lesion. Among the topical treatments corticostereoids, vitamin D3 analogs and retinoids are commonly used. However, these treatments may have adverse effects in the long term. Conversely, systemic conventional treatments include immunosuppresors such as cyclosporin or methotrexate associated with high toxicity levels. Biologicals are alternative therapeutical agents introduced in the last 10 years. These include fusion proteins or monoclonal antibodies designed to inhibit the action of specific cytokines or to prevent T-lymphocyte activation. However, due to recent knowledge on the etiology of the disease, diverse new small molecules have appeared as promising alternatives for the treatment of psoriasis. Among them, inhibitors of JAK3, inhibitors of PDE 4 and amygdalin analogs. The latter are promising small molecules presently in preclinical studies which are the object of the present report.

  18. Design and Implementation of Analog Multiplier with Improved Linearity

    Directory of Open Access Journals (Sweden)

    Nandini A.S

    2012-11-01

    Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signalprocessing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.

  19. Design and Implementation of Analog Multiplier with Improved Linearity

    Directory of Open Access Journals (Sweden)

    Nandini A.S

    2012-10-01

    Full Text Available Analog multipliers are used for frequency conversion and are critical components in modern radio frequency (RF systems. RF systems must process analog signals with a wide dynamic range at high frequencies. A mixer converts RF power at one frequency into power at another frequency to make signal processing easier and also inexpensive. A fundamental reason for frequency conversion is to allow amplification of the received signal at a frequency other than the RF, or the audio, frequency. This paper deals with two such multipliers using MOSFETs which can be used in communication systems. They were designed and implemented using 0.5 micron CMOS process. The two multipliers were characterized for power consumption, linearity, noise and harmonic distortion. The initial circuit simulated is a basic Gilbert cell whose gain is fairly high but shows more power consumption and high total harmonic distortion. Our paper aims in reducing both power consumption and total harmonic distortion. The second multiplier is a new architecture that consumes 43.07 percent less power and shows 22.69 percent less total harmonic distortion when compared to the basic Gilbert cell. The common centroid layouts of both the circuits have also been developed.

  20. Planar CMOS analog SiPMs: design, modeling, and characterization

    Science.gov (United States)

    Zou, Yu; Villa, Federica; Bronzi, Danilo; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2015-11-01

    Silicon photomultipliers (SiPMs) are large area detectors consisting of an array of single-photon-sensitive microcells, which make SiPMs extremely attractive to substitute the photomultiplier tubes in many applications. We present the design, fabrication, and characterization of analog SiPMs in standard planar 0.35 μm CMOS technology, with about 1 mm × 1 mm total area and different kinds of microcells, based on single-photon avalanche diodes with 30 μm diameter reaching 21.0% fill-factor (FF), 50 μm diameter (FF = 58.3%) or 50 μm square active area with rounded corner of 5 μm radius (FF = 73.7%). We also developed the electrical SPICE model for CMOS SiPMs. Our CMOS SiPMs have 25 V breakdown voltage, in line with most commercial SiPMs and higher gain (8.8 × 106, 13.2 × 106, and 15.0 × 106, respectively). Although dark count rate density is slightly higher than state-of-the-art analog SiPMs, the proposed standard CMOS processing opens the feasibility of integration with active electronics, for switching hot pixels off, drastically reducing the overall dark count rate, or for further on-chip processing.

  1. The analog signal processing board for the HEAT telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, M.; Aramo, C.; Boiano, A. [Sezione INFN, Napoli (Italy); Cilmo, M., E-mail: cilmo@na.infn.it [Sezione INFN, Napoli (Italy); D' Urso, D.; Guarino, F.; Mangone, C.; Valore, L. [Sezione INFN, Napoli (Italy); Universita di Napoli ' Federico II' (Italy); Yushkov, A. [Sezione INFN, Napoli (Italy)

    2011-12-21

    The aim of the Pierre Auger Observatory is to measure with high statistics the flux, the arrival directions and the mass composition of cosmic rays at the highest energies. Since 2009, the Auger Collaboration has added three new High Elevation Auger Telescopes (HEAT) along with a new 25 km{sup 2} infill array in the field of view of the new telescopes. These enhancements have lowered the energy threshold of the Observatory by about an order of magnitude. In combination with the existing telescopes in Coihueco the vertical field of view is extended to about 60 Degree-Sign , allowing the measurement of nearby air showers arising from primaries with energies as low as 2 Multiplication-Sign 10{sup 17} eV. In this paper we describe the new front-end analog board developed to process the signals generated by the photomultipliers of the HEAT telescopes. Eighty analog boards have been produced, fully characterized and tested. The main characteristics of the electronic circuits and the circuit parameters are illustrated.

  2. Insulin Analogs Applied with Continuous Subcutaneous Insulin Infusion (Pump in the Treatment of Diabetes

    Directory of Open Access Journals (Sweden)

    Ercan Tuncel

    2015-03-01

    Full Text Available Diabetes mellitus (DM is an important health problem that should be treated efficiently because of its high prevalence and high morbidity and mortality due to its complications. In patients with DM, the application of a treatment which provides physiologic insulin secretion as such in healthy individuals is directly related with the prevention of diabetes complications. Insulin analogs, which were developed in recent years and shown to have pharmacokinetic and pharmacodynamic superiority to human insulin, have made it possible to obtain natural insulin pattern in the body. In addition to development of insulin analogs, introduction of insulin application method of “continuous subcutaneous insulin infusion” (insulin pump has led a new era in the treatment of DM. In this review, treatment of type 1 and 2 DM patients with insulin analogs, particularly insulin aspart, applied with insulin pump was discussed in the light of the current literature.

  3. Low-power analog integrated circuits for wireless ECG acquisition systems.

    Science.gov (United States)

    Tsai, Tsung-Heng; Hong, Jia-Hua; Wang, Liang-Hung; Lee, Shuenn-Yuh

    2012-09-01

    This paper presents low-power analog ICs for wireless ECG acquisition systems. Considering the power-efficient communication in the body sensor network, the required low-power analog ICs are developed for a healthcare system through miniaturization and system integration. To acquire the ECG signal, a low-power analog front-end system, including an ECG signal acquisition board, an on-chip low-pass filter, and an on-chip successive-approximation analog-to-digital converter for portable ECG detection devices is presented. A quadrature CMOS voltage-controlled oscillator and a 2.4 GHz direct-conversion transmitter with a power amplifier and upconversion mixer are also developed to transmit the ECG signal through wireless communication. In the receiver, a 2.4 GHz fully integrated CMOS RF front end with a low-noise amplifier, differential power splitter, and quadrature mixer based on current-reused folded architecture is proposed. The circuits have been implemented to meet the specifications of the IEEE 802.15.4 2.4 GHz standard. The low-power ICs of the wireless ECG acquisition systems have been fabricated using a 0.18 μm Taiwan Semiconductor Manufacturing Company (TSMC) CMOS standard process. The measured results on the human body reveal that ECG signals can be acquired effectively by the proposed low-power analog front-end ICs.

  4. Treatment of obesity and diabetes using oxytocin or analogs in patients and mouse models.

    Directory of Open Access Journals (Sweden)

    Hai Zhang

    Full Text Available Obesity is important for the development of type-2 diabetes as a result of obesity-induced insulin resistance accompanied by impaired compensation of insulin secretion from pancreatic beta cells. Here, based on a randomized pilot clinical trial, we report that intranasal oxytocin administration over an 8-week period led to effective reduction of obesity and reversal of related prediabetic changes in patients. Using mouse models, we further systematically evaluated whether oxytocin and its analogs yield therapeutic effects against prediabetic or diabetic disorders regardless of obesity. Our results showed that oxytocin and two analogs including [Ser4, Ile8]-oxytocin or [Asu1,6]-oxytocin worked in mice to reverse insulin resistance and glucose intolerance prior to reduction of obesity. In parallel, using streptozotocin-induced diabetic mouse model, we found that treatment with oxytocin or its analogs reduced the magnitude of glucose intolerance through improving insulin secretion. The anti-diabetic effects of oxytocin and its analogs in these animal models can be produced similarly whether central or peripheral administration was used. In conclusion, oxytocin and its analogs have multi-level effects in improving weight control, insulin sensitivity and insulin secretion, and bear potentials for being developed as therapeutic peptides for obesity and diabetes.

  5. Status of the CALICE analog calorimeter technological prototypes

    CERN Document Server

    Terwort, Mark

    2012-01-01

    The CALICE collaboration is currently developing engineering prototypes of electromagnetic and hadronic calorimeters for a future linear collider detector. This detector is designed to be used in particle-flow based event reconstruction. In particular, the calorimeters are optimized for the individual reconstruction and separation of electromagnetic and hadronic showers. They are conceived as sampling calorimeters with tungsten and steel absorbers, respectively. Two electromagnetic calorimeters are being developed, one with silicon-based active layers and one based on scintillator strips that are read out by MPPCs, allowing highly granular readout. The analog hadron calorimeter is based on scintillating tiles that are also read out individually by silicon photomultipliers. The multi-channel, auto-triggered front-end chips are integrated into the active layers of the calorimeters and are designed for minimal power consumption (power pulsing). The goal of the construction of these prototypes is to demonstrate t...

  6. Analog models of computations \\& Effective Church Turing Thesis: Efficient simulation of Turing machines by the General Purpose Analog Computer

    CERN Document Server

    Pouly, Amaury; Graça, Daniel S

    2012-01-01

    \\emph{Are analog models of computations more powerful than classical models of computations?} From a series of recent papers, it is now clear that many realistic analog models of computations are provably equivalent to classical digital models of computations from a \\emph{computability} point of view. Take, for example, the probably most realistic model of analog computation, the General Purpose Analog Computer (GPAC) model from Claude Shannon, a model for Differential Analyzers, which are analog machines used from 1930s to early 1960s to solve various problems. It is now known that functions computable by Turing machines are provably exactly those that are computable by GPAC. This paper is about next step: understanding if this equivalence also holds at the \\emph{complexity} level. In this paper we show that the realistic models of analog computation -- namely the General Purpose Analog Computer (GPAC) -- can simulate Turing machines in a computationally efficient manner. More concretely we show that, modulo...

  7. Synthetic Biology: A Unifying View and Review Using Analog Circuits.

    Science.gov (United States)

    Teo, Jonathan J Y; Woo, Sung Sik; Sarpeshkar, Rahul

    2015-08-01

    We review the field of synthetic biology from an analog circuits and analog computation perspective, focusing on circuits that have been built in living cells. This perspective is well suited to pictorially, symbolically, and quantitatively representing the nonlinear, dynamic, and stochastic (noisy) ordinary and partial differential equations that rigorously describe the molecular circuits of synthetic biology. This perspective enables us to construct a canonical analog circuit schematic that helps unify and review the operation of many fundamental circuits that have been built in synthetic biology at the DNA, RNA, protein, and small-molecule levels over nearly two decades. We review 17 circuits in the literature as particular examples of feedforward and feedback analog circuits that arise from special topological cases of the canonical analog circuit schematic. Digital circuit operation of these circuits represents a special case of saturated analog circuit behavior and is automatically incorporated as well. Many issues that have prevented synthetic biology from scaling are naturally represented in analog circuit schematics. Furthermore, the deep similarity between the Boltzmann thermodynamic equations that describe noisy electronic current flow in subthreshold transistors and noisy molecular flux in biochemical reactions has helped map analog circuit motifs in electronics to analog circuit motifs in cells and vice versa via a `cytomorphic' approach. Thus, a body of knowledge in analog electronic circuit design, analysis, simulation, and implementation may also be useful in the robust and efficient design of molecular circuits in synthetic biology, helping it to scale to more complex circuits in the future.

  8. Human performance profiles for planetary analog extra-vehicular activities: 120 day and 30 day analog missions

    Science.gov (United States)

    Swarmer, Tiffany M.

    Understanding performance factors for future planetary missions is critical for ensuring safe and successful planetary extra-vehicular activities (EVAs). The goal of this study was to gain operational knowledge of analog EVAs and develop biometric profiles for specific EVA types. Data was collected for a 120 and 30 day analog planetary exploration simulation focusing on EVA type, pre and post EVA conditions, and performance ratings. From this five main types of EVAs were performed: maintenance, science, survey/exploratory, public relations, and emergency. Each EVA type has unique characteristics and performance ratings showing specific factors in chronological components, environmental conditions, and EVA systems that have an impact on performance. Pre and post biometrics were collected to heart rate, blood pressure, and SpO2. Additional data about issues and specific EVA difficulties provide some EVA trends illustrating how tasks and suit comfort can negatively affect performance ratings. Performance decreases were noted for 1st quarter and 3rd quarter EVAs, survey/exploratory type EVAs, and EVAs requiring increased fine and gross motor function. Stress during the simulation is typically higher before the EVA and decreases once the crew has returned to the habitat. Stress also decreases as the simulation nears the end with the 3rd and 4th quarters showing a decrease in stress levels. Operational components and studies have numerous variable and components that effect overall performance, by increasing the knowledge available we may be able to better prepare future crews for the extreme environments and exploration of another planet.

  9. The development of analogical inference in children living in slums

    National Research Council Canada - National Science Library

    Mariela Orozco-Hormaza; Elda Cerchiaro-Ceballos

    2012-01-01

    ... son capaces de solucionar el problema utilizando la estrategia que requiere establecer inferencia y relaciones de analoga, aunque el porcentaje de nios de 5 aos que la usa es significativamente mayor que el de los otros dos grupos. Los resultados obtenidos permiten discutir dos tendencias en el desarrollo cognitivo: una centrada en la edad y la otra en el ...

  10. Synthesis and biodistribution of radioiodinated nicotine analogs

    Energy Technology Data Exchange (ETDEWEB)

    Chan, S.M.; Basmadjian, G.P.; Marten, D.F.; Sadek, S.; Magarian, R.A.; Grunder, J.R.; Ice, R.D.

    1984-01-01

    The authors reported previously on the synthesis and biodistribution of radioiodinated 5-iodonicotine. In their continuous effort to search for a potential brain as well as adrenal medulla imaging agent, the authors synthesized four radioiodinated nicotine analogs. The labeled compounds were prepared by brominating nicotinic acid, and reacting the acylated product with the appropriate amines to give the respective amides which were then reduced with diborane to the amines. I-125 labeling was done by halogen exchange. Biodistribution studies performed in female Sprague-Dawley rats showed that all these compounds were taken up rapidly by the brain and the adrenal. The highest uptake of all these compounds in both organs occurred at 2 minutes after tail vein injections. The organ:blood ratios at 2 minutes and the T/sub 1/3/ (min.) of radioactivity in these organs were compared.

  11. Analog model for an expanding universe

    CERN Document Server

    Weinfurtner, S E C

    2004-01-01

    Over the last few years numerous papers concerning analog models for gravity have been published. It was shown that the dynamical equation of several systems (e.g. Bose-Einstein condensates with a sink or a vortex) have the same wave equation as light in a curved-space (e.g. black holes). In the last few months several papers were released which deal with simulations of the universe. In this article the de-Sitter universe will be compared with a freely expanding three-dimensional spherical Bose-Einstein condensate. Initially the condensate is in a harmonic trap, which suddenly will be switched off. At the same time a small perturbation will be injected in the center of the condensate cloud. The motion of the perturbation in the expanding condensate will be discussed, and after some transformations the similarity to an expanding universe will be shown.

  12. Synthetic analogs of bacterial quorum sensors

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Rashi (Los Alamos, NM); Ganguly, Kumkum (Los Alamos, NM); Silks, Louis A. (Los Alamos, NM)

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  13. Z~+(4430) and Analogous Heavy Flavor States

    Institute of Scientific and Technical Information of China (English)

    DING Gui-jun

    2009-01-01

    We have studied Z~+ (4430)as a D~* D_1 molecule from the quark model,state mixing effect is considered by solving the coupled channel Schr(o)dinger equation numerically.More precise measurements of Z~+ (4430)mass and width,partial wave analysis are helpful to understand its structure.If it lies below the D~* D_1 threshold,molecule interpretation with J~P=1~- is favored,and JP =0~- can not be ruled out.Otherwise Z~+ (4430)may be a virtual state with J~P=2~-.The analogous heavy flavor mesons Z~+_(bb) and Z~(++)_(bc) are considered as well,and the masses predicted in our model are in agreement with the predictions from the potential model and QCD sum rule.

  14. Analog computing using reflective plasmonic metasurfaces

    CERN Document Server

    Pors, Anders; Bozhevolnyi, Sergey I

    2016-01-01

    Motivated by the recent renewed interest in compact analog computing using light and metasurfaces (Silva, A. et al., Science 2014, 343, 160-163), we suggest a practical approach to its realization that involves reflective metasurfaces consisting of arrayed gold nanobricks atop a subwavelength-thin dielectric spacer and optically-thick gold film, a configuration that supports gap-surface plasmon resonances. Using well established numerical routines, we demonstrate that these metasurfaces enable independent control of the light phase and amplitude, and design differentiator and integrator metasurfaces featuring realistic system parameters. Proof-of-principle experiments are reported along with the successful realization of a high-quality poor-man's integrator metasurface operating at the wavelength of 800 nm.

  15. Analogies and metaphors in clinical medicine.

    Science.gov (United States)

    Masukume, Gwinyai; Zumla, Alimuddin

    2012-02-01

    Medicine is traditionally known as an 'art', and not an exact 'science'. Medical images of clinical signs and pathology were communicated through 'metaphors' in the 19th and early 20th centuries to make recognition easier in anticipation of the clinical counterpart when encountered in medical practice. They have served as teaching aids, enhancing memory retention for medical students, nurses and doctors and have withstood the test of time. Standard medical textbooks contain metaphors that have become entrenched in teaching, learning and examining in medical schools and hospitals worldwide. The continued use of metaphors has given rise to an ongoing debate, particularly in Africa, due to the usage of inappropriate or unfamiliar metaphors which are not locally or culturally relevant. Despite this, medical analogies will no doubt continue to be useful for medical education, clinical practice and 'aide memoirs' for examinations, and bring light humour, for a long time to come.

  16. Ultra Low-Power Analog Median Filters

    Directory of Open Access Journals (Sweden)

    A. Diaz-Sanchez

    2013-09-01

    Full Text Available The design and implementation of three analog median filter topologies, whose transistors operate in the deep weak-inversion region, is described. The first topology is a differential pairs array, in which drain currents are driven into two nodes in a differential fashion, while the second topology is based on a wide range OTA, which is used to maximize the dynamic range. Finally, the third topology uses three range-extended OTAs. The proposed weak-inversion filters were designed and fabricated in ON Semiconductor 0.5 micrometer technology through MOSIS. Experimental results of three-input fabricated prototypes for all three topologies are show, where power consumptions of 90nW in the first case, and 270nW in the other two cases can be noticed. A dual power supply +/-1.5 Volts were used.

  17. Analog circuit for controlling acoustic transducer arrays

    Energy Technology Data Exchange (ETDEWEB)

    Drumheller, Douglas S. (Cedar Crest, NM)

    1991-01-01

    A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.

  18. Atwood and Poggendorff: an insightful analogy

    DEFF Research Database (Denmark)

    Coelho, Ricardo; Borges, Paulo; Avelar Sotomaior Karam, Ricardo

    2016-01-01

    - librium provide us with the solution for a compound Atwood machine with the same bodies. This analogy is pedagogically useful because it illustrates a common strategy to transform a dynamic in a static situation improving stu- dents’ comprehension of Newton’s laws and equilibrium.......Atwood’s treatise, in which the Atwood machine appears, was published in 1784. About 70 years later, Poggendorff showed experimentally that the weight of an Atwood machine is reduced when it is brought to motion. In the present paper, a twofold connection between this experiment and the Atwood...... machine is established. Firstly, if the Poggendorff apparatus is taken as an ideal one, the equations of motion of the apparatus coincide with the equations of motion of the compound Atwood machine. Secondly, if the Poggendorff apparatus, which works as a lever, is rebalanced, the equations of this equi...

  19. A Probabilistic Approach to Pronunciation by Analogy

    CERN Document Server

    Kujala, Janne V

    2011-01-01

    The relationship between written and spoken words is convoluted in languages with a deep orthography such as English and therefore it is difficult to devise explicit rules for generating the pronunciations for unseen words. Pronunciation by analogy (PbA) is a data-driven method of constructing pronunciations for novel words from concatenated segments of known words and their pronunciations. PbA performs relatively well with English and outperforms several other proposed methods. However, the best published word accuracy of 65.5% (for the 20,000 word NETtalk corpus) suggests there is much room for improvement in it. Previous PbA algorithms have used several different scoring strategies such as the product of the frequencies of the component pronunciations of the segments, or the number of different segmentations that yield the same pronunciation, and different combinations of these methods, to evaluate the candidate pronunciations. In this article, we instead propose to use a probabilistically justified scorin...

  20. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.