Sample records for analog efecto citotoxico

  1. Cytotoxic and genotoxic effects caused by {sup 153} Sm-EDTMP, combined with BrdU a thymidine analog; Efecto citotoxico y genotoxico causado por {sup 153} Sm-EDTMP, combinado con BrdU un analogo de timidina

    Morales A, E.; Ferro F, G.; Morales R, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)


    The ablation of the bone marrow previous to the transplant by means of radiation and chemical antineoplastics its affect indiscriminately to the healthy tissues and in particular those that are in proliferation. The objective of this work is to determine the effect of the incorporation from the BrdU to the DNA on the genotoxicity and cytotoxicity of the cells of the bone marrow caused by the radiopharmaceutical {sup 153}Sm-EDTMP. The genotoxicity was determined by the rate of erythrocytes polychromatic micro nucleates (EPC-MN) and the cytotoxicity by the frequency of EPC. Both parameters determined in peripheral blood after the BrdU administration and {sup 153}Sm-EDTMP. The combination of the BrdU and r1 radiopharmaceutical produced a bigger cytotoxicity that the radiation and the BrdU alone; on the other hand it produced a reduction of the EPC-MN produced by the radiation, suggesting that the cytotoxicity didn't allow the expression of the genotoxicity. (Author)

  2. Interferon Analogs

    Poelstra, Klaas; Prakash, Jai; Beljaars, Eleonora; Bansal, Ruchi


    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  3. Interferon Analogs

    Poelstra, Klaas; Prakash, Jai; Beljaars, Leonie; Bansal, Ruchi


    The invention relates to the field of medicine. Among others, it relates to biologically active analogs of interferons (IFNs) which show less unwanted side-effects and to the therapeutic uses thereof. Provided is an IFN analog, wherein the moiety mediating binding to its natural receptor is at least

  4. Analog earthquakes

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


    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.

  5. Efectos colaterales del voto preferente

    Luis Diego Brenes Villalobos


    Full Text Available El artículo describe la multiplicidad de potenciales efectos que la implementación del voto preferente podría acarrear en el ordenamiento jurídico y el sistema de partidos. La primera parte del análisis se dirige a caracterizar y definir el voto preferencial. En segunda instancia, el estudio comprenderá la revista de los efectos colaterales del voto preferente como modalidad de votación.

  6. Analog model

    The invention relates to devices for modelling the space-dependent kinetics of a nuclear reactor. It can be advantageously used in studying the dynamics of the neutron field in the core to determine the effect of the control rods on the power distribution in the core, for training purposes. The proposed analog model of a nuclear reactor comprises operational amplifiers and a grid of resistors simulating neutron diffusion. Connected to the grid nodes are supply resistors modelling absorption and multiplication of neutrons. This is achieved by that, in the proposed model, all resistors through which power is supplied to the grid nodes are interconnected by their other leads and coupled to the output of the amplifier unit common for all nodes. Therewith, the amlifier unit models the transfer function of a ''point'' reactor. Connected to the input of this unit which includes two to four amplifiers are resistors for addition of signals with a grid node. Coupled to the grid nodes via additional resistors are voltage sources simulating reactivity

  7. Efecto Fotoeléctrico

    González Marhuenda, Pedro


    Este vídeo tiene como objetivo el análisis del efecto fotoeléctrico, es decir de la emisión de electrones por un metal cuando sobre él incide luz (radiación electromagnética) de frecuencia superior a la denominada frecuencia umbral de ese metal. El efecto se presenta primero mediante un electroscopio casero, que permite observar la descarga de una placa de zinc, previamente cargada, con una lámpara de luz ultravioleta. Después, mediante un montaje experimental más elaborado, se analiza la cor...

  8. Analog and VLSI circuits

    Chen, Wai-Kai


    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.

  9. Science Teachers' Analogical Reasoning

    Mozzer, Nilmara Braga; Justi, Rosária


    Analogies can play a relevant role in students' learning. However, for the effective use of analogies, teachers should not only have a well-prepared repertoire of validated analogies, which could serve as bridges between the students' prior knowledge and the scientific knowledge they desire them to understand, but also know how to introduce analogies in their lessons. Both aspects have been discussed in the literature in the last few decades. However, almost nothing is known about how teachers draw their own analogies for instructional purposes or, in other words, about how they reason analogically when planning and conducting teaching. This is the focus of this paper. Six secondary teachers were individually interviewed; the aim was to characterize how they perform each of the analogical reasoning subprocesses, as well as to identify their views on analogies and their use in science teaching. The results were analyzed by considering elements of both theories about analogical reasoning: the structural mapping proposed by Gentner and the analogical mechanism described by Vosniadou. A comprehensive discussion of our results makes it evident that teachers' content knowledge on scientific topics and on analogies as well as their pedagogical content knowledge on the use of analogies influence all their analogical reasoning subprocesses. Our results also point to the need for improving teachers' knowledge about analogies and their ability to perform analogical reasoning.

  10. Intuitive analog circuit design

    Thompson, Marc


    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

  11. Analog and hybrid computing

    Hyndman, D E


    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

  12. sujetos a Efectos de Red

    José Luis Arroyo Barrigüete


    Full Text Available El objetivo del presente artículo es analizar una de las principales características de la Economía Digital: las Externalidades de Red. Dichas Externalidades inducen en los mercados una realimentación positiva que lleva en muchos casos a situaciones prácticamente monopolísticas. Se identificarán aquellas capacidades internas de las empresas que resultan críticas para lograr el éxito en presencia de Efectos de Red así como las principales estrategias que es posible desarrollar en este contexto.

  13. Insulin analogs and cancer

    Laura eSciacca


    Full Text Available Today, insulin analogs are used in millions of diabetic patients. Insulin analogs have been developed to achieve more physiological insulin replacement in terms of time course of the effect. Modifications in the amino acid sequence of the insulin molecule change the pharmacokinetics and pharmacodynamics of the analogs in respect to human insulin. However, these changes can also modify the molecular and biological effects of the analogs. The rapid-acting insulin analogs, lispro, aspart and glulisine, have a rapid onset and shorter duration of action. The long-acting insulin analogs glargine and detemir have a protracted duration of action and a relatively smooth serum concentration profile. Insulin and its analogs may function as growth factors and therefore have a theoretical potential to promote tumor proliferation. A major question is whether analogs have an increased mitogenic activity in respect to insulin. These ligands can promote cell proliferation through many mechanisms like the prolonged stimulation of the insulin receptor, stimulation of the IGF-1 receptor (IGF-1R, prevalent activation of the ERK rather than the AKT intracellular post-receptor pathways. Studies on in vitro models indicate that short-acting analogs elicit molecular and biological effects that are similar to those of insulin. In contrast, long-acting analogs behave differently. Although not all data are homogeneous, both glargine and detemir have been found to have a decreased binding to IR but an increased binding to IGF-1R, a prevalent activation of the ERK pathway, and an increased mitogenic effect in respect to insulin. Recent retrospective epidemiological clinical studies have suggested that treatment with long-acting analogs (specifically glargine may increase the relative risk for cancer. Results are controversial and methodologically weak. Therefore prospective clinical studies are needed to evaluate the possible tumor growth-promoting effects of these insulin

  14. The Analogical Mind

    Holyoak, Keith J.; Thagard, P.


    We examine the use of analogy in human thinking from the perspective of a multiconstraint theory, which postulates three basic types of constraints: similarity, structure and purpose. The operation of these constraints is apparent in both laboratory experiments on analogy and in naturalistic settings, including politics, psychotherapy, and scientific research. We sketch how the multiconstraint theory can be implemented in detailed computational simulations of the analogical human mind.

  15. Analog circuit design

    Dobkin, Bob


    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. <

  16. Analog synthetic biology.

    Sarpeshkar, R


    We analyse the pros and cons of analog versus digital computation in living cells. Our analysis is based on fundamental laws of noise in gene and protein expression, which set limits on the energy, time, space, molecular count and part-count resources needed to compute at a given level of precision. We conclude that analog computation is significantly more efficient in its use of resources than deterministic digital computation even at relatively high levels of precision in the cell. Based on this analysis, we conclude that synthetic biology must use analog, collective analog, probabilistic and hybrid analog-digital computational approaches; otherwise, even relatively simple synthetic computations in cells such as addition will exceed energy and molecular-count budgets. We present schematics for efficiently representing analog DNA-protein computation in cells. Analog electronic flow in subthreshold transistors and analog molecular flux in chemical reactions obey Boltzmann exponential laws of thermodynamics and are described by astoundingly similar logarithmic electrochemical potentials. Therefore, cytomorphic circuits can help to map circuit designs between electronic and biochemical domains. We review recent work that uses positive-feedback linearization circuits to architect wide-dynamic-range logarithmic analog computation in Escherichia coli using three transcription factors, nearly two orders of magnitude more efficient in parts than prior digital implementations. PMID:24567476

  17. Hydraulic Capacitor Analogy

    Baser, Mustafa


    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…

  18. Analog pulse processor

    Wessendorf, Kurt O.; Kemper, Dale A.


    A very low power analog pulse processing system implemented as an ASIC useful for processing signals from radiation detectors, among other things. The system incorporates the functions of a charge sensitive amplifier, a shaping amplifier, a peak sample and hold circuit, and, optionally, an analog to digital converter and associated drivers.

  19. Efectos citotoxicos in vitro de extractos y fracciones de Espeletia killipii Cuatr. frente a lineas celulares tumorales humanos Efeitos citotóxicos in vitro de extratos e frações de Espeletia killipii Cuatr. frente a linhas celulares tumorais humanas In vitro cytotoxic effects of extract and fractions of Espeletia killipii Cuatr. against human tumor cell lines

    Alba N. Téllez Alfonso


    Full Text Available O extrato etanólico e as frações de Espeletia killipii (espécie endêmica da vegetação dos páramos do altiplano Cundiboyacense; mostraram atividade citotóxica significativa in vitro nas linhagens celulares tumorais humanas de câncer de mama MCF-7, CSC-1170, CSC-1595, CSC-3322, CSC-3325 e na linhagem Hep-2 de laringe. A fração CH2Cl2 e suas sub-frações foram ativas contra as linhagens celulares cancerígenas de mama na concentração de 50 µg/mL, obtendo-se percentagens de viabilidade entre 13 e 20%. O principio ativo ainda não identificado foi obtido por ensaios bioguiados sucessivos e apresentou valores de Concentração Citotóxica media (CC50 menores que 1 µg/mL para as linhagens celulares colombianas CSC-1170, CSC-1595, CSC-3322 e CSC-3325; CC50 = 1 µg/mL contra MDA MB 435 e NCl-H23; contra MCF-7 uma CC50 = 2 µg/mL e uma CC50 superior a 16 µg/mL contra PC-3 e U-251.It was found that the ethanol extracts and fractions of Espeletia killipii (an endemic species of the páramo vegetation of the Cundiboyacense plateau exhibited cytotoxic activity against several human tumor cell lines. Thus, the extracts and fractions exhibited significant cytotoxic activity against both the human tumor cell lines of breast cancer MCF-7, CSC-1170, CSC-1595, CSC-3322, CSC-3325 and the Hep-2 cell lines of laryns. The CH2Cl2 fraction and its sub-fractions were active against the breast lines at concentration of 50 µg/mL, with a viability percentage between 13 and 20%. The active principle, not identified yet, was obtained by successive bio-directed assays. It showed activity against the Colombian cell lines CSC-1170, CSC-1595, CSC-3322 and CSC-3325 at a half Cytotoxic Concentration (CC50 less than 1 µg/mL, against MDA MB-435 and NCI-H23 at CC50= 1 µg/mL against MCF-7 at CC50= 2 µg/mL, and against PC-3 and U-251 at CC50 greater than 16 µg/mL.

  20. Meat analog: a review.

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S


    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320

  1. Troubleshooting analog circuits

    Pease, Robert A


    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

  2. Challenges in Analogical Reasoning

    Lin, Shih-Yin


    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.

  3. TV Analog Station Transmitters

    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...

  4. Analog circuits cookbook

    Hickman, Ian


    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.

  5. Synthesis of Paclitaxel Analogs

    Xu, Zhibing


    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...

  6. Electrical Circuits and Water Analogies

    Smith, Frederick A.; Wilson, Jerry D.


    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)

  7. Digital and analog communication systems

    Shanmugam, K. S.


    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.

  8. Analogical Reasoning in Geometry Education

    Magdas, Ioana


    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…

  9. Electrical analogous in viscoelasticity

    Ala, Guido; Di Paola, Mario; Francomano, Elisa; Li, Yan; Pinnola, Francesco P.


    In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical experiments based on finite difference time domain method shows that, for long time simulations, the correct time behavior can be obtained only with modal analysis. The use of electrical analogous in viscoelasticity can better reveal the real behavior of fractional hereditary materials.

  10. Quantum Analog Computing

    Zak, M.


    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.

  11. Towards analogy in toponyms

    Štěpán, Pavel

    Cluj : Mega, 2013 - (Felecan, O.), s. 379-383 ISBN 978-606-543-343-4. [Name and Naming /2./ Onomastics in Contemporary Public Space. Baia Mare (RO), 09.05.2013-11.05.2013] R&D Projects: GA ČR GPP406/12/P600 Institutional support: RVO:68378092 Keywords : onomastics * toponyms * analogy Subject RIV: AI - Linguistics

  12. El efecto fotoeléctrico

    M. A. Rodríguez-Meza


    Full Text Available Se presenta una revisión del trabajo de Albert Einstein de 1905 que popularmente se conoce como del efecto fotoeléctrico, y por el cual se le otorgó el premio Nobel en 1921. Mostramos que para Einstein el efecto en sí no era importante, sino que estaba interesado en entender los procesos de emisión y absorción de radiación por la materia. Veremos también que al entender la termodinámica de la radiación electromagnética en una cavidad en equilibrio térmico a una temperatura dada, Einstein pudo plantear su hipótesis de los quanta que aplicó a tres fenómenos de interés en esos años, entre ellos el efecto fotoeléctrico.

  13. Efectos digitales de audio con Web Audio API



    El presente trabajo consiste en un estudio de la capacidad de Web Audio API para el procesado de efectos de audio en tiempo real. De todos los efectos de audio posibles se han elegido el wah-wah, el flanger y el choris, efectos ampliamente empleados con guitarra eléctrica. Se crean funciones de lenguaje JavaScript que modelan el comportamiento de los efectos de audio elegidos, haciéndolas funcionar sobre una plataforma web HTML5. García Chaparro, S. (2015). Efectos digitales de audio con W...

  14. Terrestrial Spaceflight Analogs: Antarctica

    Crucian, Brian


    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.

  15. USW area analogs

    Everett, Keith R.


    The purpose of this project is to investigate the feasibility of and methodology for the development of a set of environmental analogs of operational Undersea Warfare (USW) areas within fleet training areas. It is primarily a discussion of the identification of parameters that characterize the tactical USW environment, prioritization of these parameters, identification of existing databases that contain these parameters and an outline of the processes required to extract the desired data fro...

  16. Analogy, Explanation, and Proof

    John eHummel


    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.

  17. ADSL Analog Front End

    Stojković, Nino


    In this paper the Asymmetric Digital Subscriber Line (ADSL) analog front end (AFE) designs are described and compared. AFE is the part of ADSL modems most responsible for quality signal transmission over phone wires. It can be divided into the transmitting path (TX) circuitry, the receiving path (RX) circuitry and the hybrid network and transformer. The operations and realizations of each functional block are presented. There are the D/A converter, the filter and the line driver in the TX pat...

  18. Analog Signal Processing

    Caloz, Christophe; Gupta, Shulabh; Zhang, Qingfeng; Nikfal, Babak


    Analog signal processing (ASP) is presented as a systematic approach to address future challenges in high speed and high frequency microwave applications. The general concept of ASP is explained with the help of examples emphasizing basic ASP effects, such as time spreading and compression, chirping and frequency discrimination. Phasers, which represent the core of ASP systems, are explained to be elements exhibiting a frequency-dependent group delay response, and hence a nonlinear phase resp...

  19. A Transiting Jupiter Analog

    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


    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 ...

  20. Los primeros minutos del efecto invernadero

    Corominas, Josep


    Esta actividad práctica muestra cómo determinados gases absorben la radiación infrarroja (de longitud de onda larga), lo cual permite explicar lo que ocurre a gran escala en la atmósfera de la Tierra en el llamado «efecto invernadero».

  1. Spiral structure in galaxies: analogies

    Kirkpatrick, R.C.


    The vortex analogy to galactic spiral structures is considered. Caution against carrying the analogy past its region of applicability is noted; and some experiments with vorticities are mentioned. (JFP)

  2. The Age of Analog Networks

    Mattiussi, Claudio; Swiss Federal Institute of Technology in Lausanne (EPFL); Marbach, Daniel; Swiss Federal Institute of Technology in Lausanne (EPFL); Dürr, Peter; Swiss Federal Institute of Technology in Lausanne (EPFL); Floreano, Dario; Swiss Federal Institute of Technology in Lausanne (EPFL)


    A large class of systems of biological and technological relevance can be described as analog networks, that is, collections of dynamical devices interconnected by links of varying strength. Some examples of analog networks are genetic regulatory networks, metabolic networks, neural networks, analog electronic circuits, and control systems. Analog networks are typically complex systems which include nonlinear feedback loops and possess temporal dynamics at different timescales. When tackled b...

  3. ESD analog circuits and design

    Voldman, Steven H


    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

  4. Discrete Calculus by Analogy

    Izadi, F A; Bagirov, G


    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  5. An analog electronic cochlea

    Lyon, Richard F.; Mead, Carver


    An engineered system that hears, such as a speech recognizer, can be designed by modeling the cochlea, or inner ear, and higher levels of the auditory nervous system. To be useful in such a system, a model of the cochlea should incorporate a variety of known effects, such as an asymmetric low-pass/bandpass response at each output channel, a short ringing time, and active adaptation to a wide range of input signal levels. An analog electronic cochlea has been built in CMOS VLSI technolog...

  6. Vorticity in analog gravity

    Cropp, Bethan; Liberati, Stefano; Turcati, Rodrigo


    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.

  7. Feedback in analog circuits

    Ochoa, Agustin


    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...

  8. Analogy-Based Expectation Equilibrium

    Jehiel, P


    It is assumed that players bundle nodes in which other players must move into analogy classes, and players only have expectations about the average behavior in every class. A solution concept is proposed for multi-stage games with perfect information: at every node players choose best-responses to their analogy-based expectations, and expectations are correct on average over those various nodes pooled together into the same analogy classes. The approach is applied to a variety of games. It is...

  9. Beginning analog electronics through projects

    Singmin, Andrew


    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

  10. Analog and digital signal processing

    Baher, H.

    The techniques of signal processing in both the analog and digital domains are addressed in a fashion suitable for undergraduate courses in modern electrical engineering. The topics considered include: spectral analysis of continuous and discrete signals, analysis of continuous and discrete systems and networks using transform methods, design of analog and digital filters, digitization of analog signals, power spectrum estimation of stochastic signals, FFT algorithms, finite word-length effects in digital signal processes, linear estimation, and adaptive filtering.

  11. Isolated transfer of analog signals

    Bezdek, T.


    Technique transfers analog signal levels across high isolation boundary without circuit performance being affected by magnetizing reactance or leakage inductance. Transfers of analog information across isolated boundary are made by interrupting signal flow, with switch, in such a manner as to produce alternating signal which is applied to transformer.

  12. Drawing Analogies in Environmental Education

    Affifi, Ramsey


    Reconsidering the origin, process, and outcomes of analogy-making suggests practices for environmental educators who strive to disengage humans from the isolating illusions of dichotomizing frameworks. We can view analogies as outcomes of developmental processes within which human subjectivity is but an element, threading our sense of self back…

  13. Analog elements for transuranic chemistries

    A chemical extraction technique for estimating the biologically available fraction of nonessential trace elements in soils has been developed. This procedure has been used in evaluating the uptake of naturally occurring transuranic analog elements from soils into several foodstuffs. The availability of the natural elements has been compared with the availability of their analog transuranics which have been derived from global fallout

  14. Natural analog studies: Licensing perspective

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


    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.

  15. Efectos garrapaticidas de algunos aceites esenciales

    Juan F. Gil; Burillo Alquézar, Jesús; Pastor, Ana; Ringuelet, Jorge; Elder, Heriberto; Echeverri, Fernando


    Soluciones acuo-etanólicas de aceites esenciales de Lippia (3 quimiotipos), Schinus molle, Tagetes, Lavandina (dos quimiotipos), Hisopo, Romero y Ciprés, fueron sometidas a ensayos in Vitro para evaluar sus efectos sobre le supervivencia y reproducción de las garrapata Rhipicephalus (Boophilus) microplus. Los aceites de Lippia, Tagetes e Hisopo mostraron buenos niveles de inhibición de la oviposición y de mortalidad superiores al 50%, a una concentración del 1%; no obstante, a concentracio...

  16. Efecto de masticar chicle sobre la halitosis

    De Luca Monasterios, Fiorella; Chimenos Küstner, Eduardo; López López, José


    Fundamento y objetivo: Este estudio pretende estimar la prevalencia de halitosis oral en una población joven y mostrar el efecto del chicle sobre el aliento. Pacientes y método: Estudio prospectivo de campo descriptivo correlacional, de corte transversal. Se seleccionaron a conveniencia 121 jóvenes, de los que 98 concluyeron el estudio, el cual se realizó en el Hospital Odontológico Universitario-Universidad de Barcelona. El protocolo consistió en: cuestionario, evaluación clínica oral, prueb...

  17. Analog-to-digital conversion

    Pelgrom, Marcel J M


    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...

  18. Molecular modeling of fentanyl analogs



    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.

  19. Analog Systems for Gravity Duals

    Hossenfelder, S.


    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore ...

  20. Analog filters in nanometer CMOS

    Uhrmann, Heimo; Zimmermann, Horst


    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 ...

  1. Towards power centric analog design

    Svensson, Christer


    Power consumption of analog systems is poorly understoodtoday, in contrast to the very well developed analysis of digitalpower consumption. We show that there is good opportunity todevelop also the analog power understanding to a similar levelas the digital. Such an understanding will have a large impact inthe design of future electronic systems, where low power consumptionwill be crucial. Eventually we may reach a power centricanalog design methodology.

  2. El efecto abanico y la paradoja del experto

    Gómez-Ariza, Carlos J.


    La investigación sobre la memoria ha demostrado que conocer más hechos sobre algo conlleva un incremento en el tiempo de reconocimiento de información al respecto (el efecto abanico). Aunque explicable por teorías de amplio espectro sobre la cognición humana, este efecto de interferencia plantea una paradoja: ¿cómo es posible entonces que un experto en un tema no sucumba ante los efectos de la interferencia durante la recuperación? La respuesta parece estar relacionada con la capacidad para i...

  3. Efectos citotoxicos in vitro de extractos y fracciones de Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, frente a lineas celulares tumorales humanos Efeitos citotóxicos in vitro de extratos e frações de Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, frente a linhagens celulares tumorais humanos In vitro cytotoxicity of extracts and fractions of Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, against human tumor cell

    Jorge E. Robles Camargo


    Full Text Available A los extractos, fracciones y subfracciones obtenidos de hojas, flores y corteza de Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, se les evalúo su actividad citotóxica preliminar frente a las líneas celulares CSC-1595 y Colo 205, siguiendo el método de fraccionamiento guiado por bioensayo de citotoxicidad MTT. Los resultados obtenidos de esta prueba muestran a la subfracción en diclorometano-metanol (9.5:0.5 obtenida de la fracción acetato de etilo del extracto en éter de petróleo de hojas, como la que presentó las sustancias bioactivas con una marcada actividad citotóxica, con porcentajes de viabilidad del 3% y 15.3% a la concentración 30 µg/mL en las líneas tumorales humanas Colo 205 y CSC-1595 respectivamente.A atividade citotóxica de extratos frações e subfrações obtidas das folhas e cascas de Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, foram preliminarmente avaliados pelo método MTT frente a linhagens celulares tumorais CSC-1595 e Colo 205. Os resultados mostraram que a subfração diclorometano-metanol (9.5:0.5, obtidos a partir da fração acetato de etila do extrato em éter de petróleo das folhas, como sendo a que apresenta substâncias bioativas com forte atividade citotóxica, taxa de viabilidade de 3% e de 15,3% na concentração de 30 µg/mL em linhagens de células tumorais humanas Colo 205 e CSC-1595, respectivamente.To the extracts, fractions and subfractions obtained from leaves, flowers and bark of Bursera tomentosa (Jacq. Triana & Planch., Burseraceae, its preliminary cytotoxic activity against to the cellular lines CSC-1595 and Colo 205 were evaluated, following the MTT method. The results showed that dichloromethane-methanol (9.5:0.5 subfraction obtained of ethyl acetate part from petroleum extract of leaves, like to display the bioactives substances with a strong cytotoxic activity, showing viability percentage of 3% and 15,3% to the concentration 30 µg/mL in human tumor cellular lines Colo 205 and CSC-1595 respectively.

  4. El efecto coagulante de la digital

    Naranjo Villegas, Alfredo


    Se lleva a cabo un trabajo para determinar el efecto coagulante de las dosis terapéuticas de digital, empleando las técnicas de Howell, de Lee y White, y de Quick. No se encontró modificación de la protrombina en los casos observados con el método de Howell. Se encontró aceleración del tiempo de protrombina -método de Quick - en 5 de 6 casos. Hubo aceleración de la coagulabilidad sanguínea - técnica de Lee y White - en 13 de 24 cardíacos digitalizados. Las dosis que más favorecieron el ...

  5. Crows spontaneously exhibit analogical reasoning.

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


    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. PMID:25532894

  6. Analog electronics for radiation detection


    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 ...

  7. Multilateral Collaborations in Analog Research

    Cromwell, R. l.


    International collaborations in studies utilizing ground-based space flight analogs are an effective means for answering research questions common to participating agencies. These collaborations bring together worldwide experts to solve important space research questions. By collaborating unnecessary duplication of science is reduced, and the efficiency of analog use is improved. These studies also share resources among agencies for cost effective solutions to study implementation. Recently, NASA has engaged in collaborations with international partners at a variety of analog sites. The NASA Human Exploration Research Analog (HERA) is currently hosting investigator studies from NASA and from the German Space Agency (DLR). These isolation studies will answer questions in the areas of team cohesion, sleep and circadian rhythms, and neurobehavioral correlates to function. Planning for the next HERA campaign is underway as proposal selections are being made from the International Life Sciences Research Announcement (ILSRA). Studies selected from the ILSRA will be conducted across 4 HERA missions in 2017. NASA is planning collaborative studies with DLR at the :envihab facility in Cologne, Germany. Investigations were recently selected to study the effects of 0.5% CO2 exposure over 30 days of bed rest. These studies will help to determine the fidelity of this ground-based analog for studying the visual impairment intracranial pressure syndrome. NASA is also planning a multilateral collaboration at :envihab with DLR and the European Space Agency (ESA) to examine artificial gravity as a countermeasure to mitigate the effects of 60 days of bed rest. NASA is also considering collaborations with the Russian Institute for Biomedical Problems (IBMP) in studies that will utilize their Ground-based Experimental Facility (NEK). The NEK is comprised of 4 interconnected modules and a Martian surface simulator. This isolation analog can support 3 -10 crew members for long duration

  8. Application handbook for analog IC

    This book consists of ten chapters, which are prolog on analog IC and digital, basic function of OP amp for operation, characteristic on direct current and interchange, Op amp and linear circuit, nonlinear arithmetic circuit, filter circuit, oscillation circuit and V-F converter, D-A converter, A-D converter on introduction eight bit and 12 bit, I C for power supply and switching regulator. Each chapter has the explanations of specific function of the programs, filter circuit, converters. So, this book is a application handbook for analog IC.

  9. International Alligator Rivers Analog Project

    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

  10. Multichannel analog temperature sensing system

    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer

  11. Analog Input Data Acquisition Software

    Arens, Ellen


    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.

  12. Multichannel analog temperature sensing system

    Gribble, R.


    A multichannel system that protects the numerous and costly water-cooled magnet coils on the translation section of the FRX-C/T magnetic fusion experiment is described. The system comprises a thermistor for each coil, a constant current circuit for each thermistor, and a multichannel analog-to-digital converter interfaced to the computer.

  13. Efectos de la “mentalidad” conquistadora

    Edison Viveros


    Full Text Available El autor hace un análisis del proceso de conquista y colonia de América. Utiliza una técnica de rastreo documental para examinar lo que denomina “mentalidad conquistadora” a través de sus expresiones históricas. Evalúa las particularidades políticas y económicas tanto de Europa como de América en esa época, con el fin de demostrar que el choque de dos cosmovisiones, una de corte bélico y conquistador, otra con una ética de hermandad y cuidado por la tierra y los ancestros, impidió un proceso que podría haber sido sincrético. Finalmente, concluye que, pese a los efectos de esta mentalidad, y de su permanencia en los rasgos culturales americanos, este continente es un espacio de mixturas y un mundo plural, con toda la potencialidad para ser auténtico.

  14. Analog circuit design art, science and personalities

    Williams, Jim


    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

  15. Synaptic dynamics in analog VLSI.

    Bartolozzi, Chiara; Indiveri, Giacomo


    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. PMID:17716003

  16. Mechanical Analogies of Fractional Elements

    HU Kai-Xin; ZHU Ke-Qin


    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.

  17. Bottomed analog of Z+(4433)

    The newly observed Z+(4433) resonance by BELLE is believed to be a tetraquark bound state made up of (cu)(cd). We propose the bottomed analog of this bound state, namely, by replacing one of the charm quarks by a bottom quark, thus forming Zbc0,±,±±. One of the Zbc is doubly charged. The predicted mass of Zbc is around 7.6 GeV. This doubly charged bound state can be detected by its decay into Bc±π±. Similarly, we can also replace both charm quark and antiquark of the Z+(4433) by bottom quark and antiquark, respectively, thus forming Zbb the bottomonium analog of Z+(4433). The predicted mass of Zbb is about 10.7 GeV

  18. Analog Nonvolatile Computer Memory Circuits

    MacLeod, Todd


    In nonvolatile random-access memory (RAM) circuits of a proposed type, digital data would be stored in analog form in ferroelectric field-effect transistors (FFETs). This type of memory circuit would offer advantages over prior volatile and nonvolatile types: In a conventional complementary metal oxide/semiconductor static RAM, six transistors must be used to store one bit, and storage is volatile in that data are lost when power is turned off. In a conventional dynamic RAM, three transistors must be used to store one bit, and the stored bit must be refreshed every few milliseconds. In contrast, in a RAM according to the proposal, data would be retained when power was turned off, each memory cell would contain only two FFETs, and the cell could store multiple bits (the exact number of bits depending on the specific design). Conventional flash memory circuits afford nonvolatile storage, but they operate at reading and writing times of the order of thousands of conventional computer memory reading and writing times and, hence, are suitable for use only as off-line storage devices. In addition, flash memories cease to function after limited numbers of writing cycles. The proposed memory circuits would not be subject to either of these limitations. Prior developmental nonvolatile ferroelectric memories are limited to one bit per cell, whereas, as stated above, the proposed memories would not be so limited. The design of a memory circuit according to the proposal must reflect the fact that FFET storage is only partly nonvolatile, in that the signal stored in an FFET decays gradually over time. (Retention times of some advanced FFETs exceed ten years.) Instead of storing a single bit of data as either a positively or negatively saturated state in a ferroelectric device, each memory cell according to the proposal would store two values. The two FFETs in each cell would be denoted the storage FFET and the control FFET. The storage FFET would store an analog signal value

  19. A Global Analog of Cheshire Charge

    McGraw, Patrick


    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.

  20. Atheism and Analogy: Aquinas Against the Atheists

    Linford, Daniel J.


    In the 13th century, Thomas Aquinas developed two models for how humans may speak of God - either by the analogy of proportion or by the analogy of proportionality. Aquinas's doctrines initiated a theological debate concerning analogy that spanned several centuries. In the 18th century, there appeared two closely related arguments for atheism which both utilized analogy for their own purposes. In this thesis, I show that one argument, articulated by the French materialist Paul-Henri Thiry Bar...

  1. El efecto abanico y la paradoja del experto

    Carlos J. Gómez-Ariza


    Full Text Available La investigación sobre la memoria ha demostrado que conocer más hechos sobre algo conlleva un incremento en el tiempo de reconocimiento de información al respecto (el efecto abanico. Aunque explicable por teorías de amplio espectro sobre la cognición humana, este efecto de interferencia plantea una paradoja: ¿cómo es posible entonces que un experto en un tema no sucumba ante los efectos de la interferencia durante la recuperación? La respuesta parece estar relacionada con la capacidad para integrar la información en estructuras complejas de información.

  2. Efecto neuroprotector de los cannabinoides en las enfermedades neurodegenerativas

    Carlos Suero-García; Lucia Martín-Banderas; Mª Ángeles Holgado


    Objetivos: Se analiza la situación actual de las investigaciones relacionadas con las sustancias cannabinoides, así como su interacción con el organismo, clasificación, efectos terapéuticos y su uso en las enfermedades neurodegenerativas. Métodos: Se realiza una exhaustiva revisión bibliográfica relacionada con las sustancias cannabinoides y sus derivados sintéticos, haciendo especial hincapié en la forma de interactuar con el organismo y los efectos que provocan dichas interacciones. Concret...

  3. Analog circuit design art, science, and personalities

    Williams, Jim


    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

  4. Analog and mixed-signal electronics

    Stephan, Karl


    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

  5. Practical analog electronics for technicians

    Kimber, W A


    '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

  6. Classical analogy of Fano resonances

    We present an analogy of Fano resonances in quantum interference to classical resonances in the harmonic oscillator system. It has a manifestation as a coupled behaviour of two effective oscillators associated with propagating and evanescent waves. We illustrate this point by considering a classical system of two coupled oscillators and interfering electron waves in a quasi-one-dimensional narrow constriction with a quantum dot. Our approach provides a novel insight into Fano resonance physics and provides a helpful view in teaching Fano resonances

  7. Approaches to synthetic platelet analogs.

    Modery-Pawlowski, Christa L; Tian, Lewis L; Pan, Victor; McCrae, Keith R; Mitragotri, Samir; Sen Gupta, Anirban


    Platelet transfusion is routinely used for treating bleeding complications in patients with hematologic or oncologic clotting disorders, chemo/radiotherapy-induced myelosuppression, trauma and surgery. Currently, these transfusions mostly use allogeneic platelet concentrates, while products like lyophilized platelets, cold-stored platelets and infusible platelet membranes are under investigation. These natural platelet-based products pose considerable risks of contamination, resulting in short shelf-life (3-5 days). Recent advances in pathogen reduction technologies have increased shelf-life to ~7 days. Furthermore, natural platelets are short in supply and also cause several biological side effects. Hence, there is significant clinical interest in platelet-mimetic synthetic analogs that can allow long storage-life and minimum side effects. Accordingly, several designs have been studied which decorate synthetic particles with motifs that promote platelet-mimetic adhesion or aggregation. Recent refinement in this design involves combining the adhesion and aggregation functionalities on a single particle platform. Further refinement is being focused on constructing particles that also mimic natural platelet's shape, size and elasticity, to influence margination and wall-interaction. The optimum design of a synthetic platelet analog would require efficient integration of platelet's physico-mechanical properties and biological functionalities. We present a comprehensive review of these approaches and provide our opinion regarding the future directions of this research. PMID:23092864

  8. Analog computation with dynamical systems

    Siegelmann, Hava T.; Fishman, Shmuel


    Physical systems exhibit various levels of complexity: their long term dynamics may converge to fixed points or exhibit complex chaotic behavior. This paper presents a theory that enables to interpret natural processes as special purpose analog computers. Since physical systems are naturally described in continuous time, a definition of computational complexity for continuous time systems is required. In analogy with the classical discrete theory we develop fundamentals of computational complexity for dynamical systems, discrete or continuous in time, on the basis of an intrinsic time scale of the system. Dissipative dynamical systems are classified into the computational complexity classes P d, Co-RP d, NP d and EXP d, corresponding to their standard counterparts, according to the complexity of their long term behavior. The complexity of chaotic attractors relative to regular ones leads to the conjecture P d ≠ NP d. Continuous time flows have been proven useful in solving various practical problems. Our theory provides the tools for an algorithmic analysis of such flows. As an example we analyze the continuous Hopfield network.

  9. Analog-to-digital conversion

    Pelgrom, Marcel J. M


    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...

  10. Efectos del D-003 sobre patrones conductuales de roedores

    Lilia Fernández Dorta


    Full Text Available El D-003 es una mezcla de ácidos alifáticos de muy alto peso molecular purificada de la cera de la caña de azúcar con efectos hipocolesterolemizante y antiagregante plaquetario demostrados experimentalmente y en estudios clínicos Fase I y II. Los estudios experimentales y clínicos culminados han mostrado que el D-003 es seguro y bien tolerado. Sin embargo, la farmacología de la seguridad de nuevos medicamentos investiga sus efectos sobre diversos sistemas que pudieran ser blancos potenciales de toxicidad. Teniendo en cuenta que los efectos adversos relacionados con el Sistema Nervioso (SN están entre los más frecuentes para diversas áreas terapéuticas, estos estudios suelen investigar los efectos de las sustancias sobre la función y estructura del SN. La investigación de los efectos sobre patrones conductuales de roedores comúnmente representa la primera etapa de estos estudios. De acuerdo con ello, el presente estudio tuvo como objetivo investigar los efectos del tratamiento oral con D-003 (dosis únicas y repetidas sobre la actividad exploratoria, la respuesta al plato caliente, la sujeción y ejecución en varilla rotatoria y la evitación pasiva de una sola prueba de aprendizaje en ratones. Los animales se distribuyeron aleatoriamente en cinco grupos experimentales (10 animales/grupo: uno control que recibió el vehículo goma acacia-H20 y cuatro tratados con D-003 (5, 25, 100 y 400 mg/kg, respectivamente. El tratamiento oral con dosis únicas y repetidas de D-003 (400 mg/kg aumentó de forma modesta, pero significativa, la actividad exploratoria con respecto al grupo control. Sin embargo, el D-003 no modificó la respuesta en el ensayo de plato caliente, la capacidad de sujeción y ejecución motora en varilla rotatoria ni la retención del aprendizaje en el ensayo de evitación pasiva. Se necesitan estudios ulteriores que diluciden las causas por las cuales el D-003 aumenta la actividad exploratoria en ratones y que

  11. Efecto del D-004 sobre patrones conductuales en roedores

    Daisy Carbajal Quintana


    Full Text Available El D-004 es un extracto lipídico de los frutos de la palma real cubana (Roystonea regia que ha mostrado efectos protectores sobre la hyperplasia prostática (HP inducida en roedores con testosterona, pero no con dihidrotestosterona y que además, antagoniza respuestas mediadas por los ¿1-adrenoreceptores prostáticos. El D-004 mostró una modesta acción antiinflamatoria en el modelo de granuloma por algodón, modelo que se acerca más a la condición de inflamación crónica aparejada a la hiperplasia prostatica benigna (HPB en el hombre, lo que podría contribuir, en alguna medida, a su efecto en los modelos de HP. Teniendo en cuenta que los efectos adversos relacionados con el sistema nervioso (SN están entre los más frecuentes para diversas áreas terapéuticas, es obligado investigar los efectos de las sustancias sobre la función y estructura del SN. La investigación de los efectos sobre patrones conductuales de roedores comúnmente representa la primera etapa de estos estudios. El presente estudio investigó los efectos del tratamiento oral con D-004 (dosis únicas y repetidas sobre la actividad exploratoria, la respuesta al plato caliente y a las contracciones inducidas con ácido acético (200, 400 y 800 mg/kg, así como sobre la sujeción en varilla rotatoria y la fuerza de agarre en ratones (250, 500 y 1 000 mg/kg. El tratamiento oral con D-004 no modificó la actividad exploratoria, la respuesta al plato caliente y a las contracciones inducidas con ácido acético, así como la sujeción en varilla y la fuerza de agarre . El tratamiento oral con D-004 en el intervalo de dosis indicado no indujo efectos neurotóxicos, ya que no modificó ninguna de las conductas estudiadas.

  12. Automatic activation of categorical and abstract analogical relations in analogical reasoning.

    Green, Adam E; Fugelsang, Jonathan A; Dunbar, Kevin N


    We examined activation of concepts during analogical reasoning. Subjects made either analogical judgments or categorical judgments about four-word sets. After each four-word set, they named the ink color of a single word in a modified Stroop task. Words that referred to category relations were primed (as indicated by longer response times on Stroop color naming) subsequent to analogical judgments and categorical judgments. This finding suggests that activation of category concepts plays a fundamental role in analogical thinking. When colored words referred to analogical relations, priming occurred subsequent to analogical judgments, but not to categorical judgments, even though identical four-word stimuli were used for both types of judgments. This finding lends empirical support to the hypothesis that, when people comprehend the analogy between two items, they activate an abstract analogical relation that is distinct from the specific content items that compose the analogy. PMID:17263066

  13. QCD analogy for quantum gravity

    Holdom, Bob; Ren, Jing


    Quadratic gravity presents us with a renormalizable, asymptotically free theory of quantum gravity. When its couplings grow strong at some scale, as in QCD, then this strong scale sets the Planck mass. QCD has a gluon that does not appear in the physical spectrum. Quadratic gravity has a spin-2 ghost that we conjecture does not appear in the physical spectrum. We discuss how the QCD analogy leads to this conjecture and to the possible emergence of general relativity. Certain aspects of the QCD path integral and its measure are also similar for quadratic gravity. With the addition of the Einstein-Hilbert term, quadratic gravity has a dimensionful parameter that seems to control a quantum phase transition and the size of a mass gap in the strong phase.

  14. Analysis of analogies used by science teachers

    Dagher, Zoubeida R.

    Science teachers use analogies that display a rich variety of form and content. An account of science teacher analogies that relies solely on systems of analysis imported from other fields of inquiry tends to obscure the unique features of these analogies as they operate within classroom discourse. This study examines teachers' analogies in context and highlights some of their special characteristics. The purpose of this analysis is to increase our understanding of how analogies operate in naturalistic instructional settings and to generate new research questions about science teaching and learning in view of the broader dimensions of the curriculum.Science isa very human activity. It involves human actors and judgements, rivalries and antagonisms, mysteries and surprises, the creative use of metaphor and analogy. It is fallible, often uncertain, and sometimes creatively ambiguous [Lemke, 1990, p. 134].Received: 1 June 1993; Revised: 29 November 1993;

  15. Priming analogical reasoning with false memories.

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


    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. PMID:25784574

  16. Analog circuit design scalable analog circuit design, high speed D/A converters, RF power amplifiers

    Huijsing, Johan


    Preface. Part I: Scalable Analog Circuit Design. Introduction. Scalable High-Speed Analog Circuit Design; M. Vertregt, P. Scholtens. Scalable High Resolution Mixed Mode Circuit Design; R.J. Brewer. Scalable 'High Voltages' Integrated Circuit Design for XDSL Type of Applications; D. Rossi. Scalability of Wire-Line Analog Front-Ends; K. Bult. Reusable IP Analog Circuit Design; J. Hauptmann, A. Wiesbauer, H. Weinberger. Process Migration Tools for Analog and Digital Circuits; K. Francken, G. Gielen. Part II: High-Speed D/A Converters. Introduction. Introduction to High-Speed Digital-to-Analog Con

  17. Xampling: Compressed Sensing of Analog Signals

    Mishali, Moshe; Eldar, Yonina C.


    Xampling generalizes compressed sensing (CS) to reduced-rate sampling of analog signals. A unified framework is introduced for low rate sampling and processing of signals lying in a union of subspaces. Xampling consists of two main blocks: Analog compression that narrows down the input bandwidth prior to sampling with commercial devices followed by a nonlinear algorithm that detects the input subspace prior to conventional signal processing. A variety of analog CS applications are reviewed wi...

  18. Analog to Digital Conversion in Physical Measurements

    Kapitaniak, T.; Zyczkowski, K.; Feudel, U.; Grebogi, C.


    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 d...

  19. Robust hyperchaotic synchronization via analog transmission line

    Sadoudi, S.; Tanougast, C.


    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.

  20. Novel Analog For Muscle Deconditioning

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


    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.

  1. An Analog Computer for Electronic Engineering Education

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


    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…

  2. Analogical Processes and College Developmental Reading

    Paulson, Eric J.


    Although a solid body of research concerning the role of analogies in reading processes has emerged at a variety of age groups and reading proficiencies, few of those studies have focused on analogy use by readers enrolled in college developmental reading courses. The current study explores whether 232 students enrolled in mandatory (by placement…

  3. Several Forms of Fuzzy Analogical Reasoning

    Bouchon-Meunier, B; Delechamp, J.; Marsala, C.; Rifqi, M.


    We present a general framework representing analogy, on the basis of a link between variables and measures of comparison between values of variables. This analogical scheme is proven to represent a common description of several forms of reasoning used in fuzzy control or in the management of knowledge-based systems, such as deductive reasoning, inductive reasoning or prototypical reasoning, gradual reasoning.

  4. A physical analogy to fuzzy clustering

    Jantzen, Jan


    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...... the algorithm to students. The analogy suggests a possible extension of the fuzzy membership assignment equation....

  5. Novel Gemini vitamin D3 analogs

    Okamoto, Ryoko; Gery, Sigal; Kuwayama, Yoshio;


    We have synthesized 39 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] analogs having two side chains attached to carbon-20 (Gemini) with various modifications and compared their anticancer activities. Five structure-function rules emerged to identify analogs with enhanced anticancer activity. One of thes...

  6. Analog simulation of the Josephson effects

    Analog circuit techniques can be used to advantage to simulate the Josephson effects in a superconductor-insulator-superconductor tunnel junction. Details of an electronic Josephson simulator are presented, and the advantages of analog techniques over their digital counterparts for this application are discussed. The simulation of a Josephson microwave mixer is used as an example

  7. Young Children's Analogical Reasoning in Science Domains

    Haglund, Jesper; Jeppsson, Fredrik; Andersson, Johanna


    This exploratory study in a classroom setting investigates first graders' (age 7-8 years, N = 25) ability to perform analogical reasoning and create their own analogies for two irreversible natural phenomena: mixing and heat transfer. We found that the children who contributed actively to a full-class discussion were consistently successful at…

  8. Analogies in high school Brazilian chemistry textbooks

    Rosária Justi


    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.

  9. Play with Language: Overextensions as Analogies.

    Hudson, Judith; Nelson, Katherine


    Defines criteria to identify children's language overextensions and investigates how young children in the early stages of language acquisition rename objects analogically during a standardized play situation. Results indicate that analogic extensions are well within the capabilities of children from one year, eight months to two years, four…

  10. Computational approaches to analogical reasoning current trends

    Richard, Gilles


    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...

  11. Efecto de la Escolaridad sobre la Fecundidad en Nicaragua

    Bonilla, Roger


    Full Text Available Son muchos los estudios que han mostrado la asociación inversa existente entre la escolaridad y la fecundidad. El objetivo de este estudio fue cuantificar el efecto de la escolaridad sobre la fecundidad, en una muestra de 11246 mujeres de Nicaragua. Se ajustaron modelos de regresión de Poisson en donde la variable respuesta Y fue el número de hijos nacidos vivos de la mujer y la variable independiente fue la escolaridad, controlando por otros efectos como zona de residencia, tenencia de empleo, uso actual de métodos anticonceptivos, edad y una medida del nivel informativo de la mujer. Los modelos propuestos son significativos (p < 0.05 el hecho de tener escolaridad primaria hace que el riesgo de tener hijos adicionales sea 13% menor con respecto a las mujeres que no tienen escolaridad alguna. El riesgo para las mujeres con escolaridad secundaria es 40% menor (Modelo 1. El efecto interactivo de la escolaridad secundaria y más y la edad es significativo ( <0.05 (Modelo 2. El estudio suministra información útil para el apropiado diseño de políticas públicas y programas educativos.

  12. El lado oscuro de las organizaciones: efectos negativos en el factor humano

    Juana Patlán Pérez; Dolores Margarita Navarrete Zorrilla; María del Rosario García Velázquez


    El presente trabajo tiene como propósito determinar qué es el lado oscuro de las organizaciones y analizar cuáles son los efectos negativos que producen las organizaciones en el factor humano. Para tal propósito se efectuó una revisión a la literatura. El análisis de los efectos negativos que producen las organizaciones se realiza desde una perspectiva sistémica que sustenta que dichos efectos van desde provocar efectos derivados del trabajo tales como accidentes, enfermedades del trabajo, ha...

  13. Analog regulation of metabolic demand

    Muskhelishvili Georgi


    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

  14. Efecto neuroprotector de los cannabinoides en las enfermedades neurodegenerativas

    Carlos Suero-García


    Full Text Available Objetivos: Se analiza la situación actual de las investigaciones relacionadas con las sustancias cannabinoides, así como su interacción con el organismo, clasificación, efectos terapéuticos y su uso en las enfermedades neurodegenerativas. Métodos: Se realiza una exhaustiva revisión bibliográfica relacionada con las sustancias cannabinoides y sus derivados sintéticos, haciendo especial hincapié en la forma de interactuar con el organismo y los efectos que provocan dichas interacciones. Concretamente, se estudiarán sus efectos neuroantiinflamatorio y analgésico lo que conlleva al efecto neuroprotector en enfermedades neurodegenerativas tales como Alzheimer, Parkinson, Huntington, esclerosis múltiple y esclerosis lateral amiotrófica. Resultados: Desde hace miles de años la planta Cannabis Sativa ha sido utilizada por muchas culturas con distintos fines, de ocio, textiles, analgésicos, pero no es hasta finales del siglo XX cuando se empieza a incentivar los estudios científicos relacionados con ésta. La planta posee una mezcla de unos 400 componentes, de los cuales 60 pertenecen al grupo de los cannabinoides siendo los principales el cannabinol, cannabidiol y tetrahidrocannabinol. Con el descubrimiento de las sustancias cannabinoides, sus derivados, y los receptores que interactúan, se amplían las posibilidades terapéuticas teniendo un especial interés el efecto neuroprotector que estas sustancias contienen. Conclusiones. Se ha demostrado el gran potencial de los cannabinoides como sustancias terapéuticas más allá de su uso analgésico o antiemético, esto es, en enfermedades neurodegenerativas en las que pueden no solo disminuir los síntomas, sino frenar el proceso de la enfermedad. Otra posible aplicación puede ser en el campo oncológico, siendo particularmente intensa la actividad investigadora realizada en los últimos 15 años.

  15. Advances in Analog Circuit Design 2015

    Baschirotto, Andrea; Harpe, Pieter


    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.

  16. Fostering Multilateral Involvement in Analog Research

    Cromwell, Ronita L.


    International collaboration in space flight research is an effective means for conducting investigations and utilizing limited resources to the fullest extent. Through these multilateral collaborations mutual research questions can be investigated and resources contributed by each international partner to maximize the scientific benefits to all parties. Recently the international partners embraced this approach to initiate collaborations in ground-based space flight analog environments. In 2011, the International Analog Research Working Group was established, and later named the International Human Space Flight Analog Research Coordination Group (HANA). Among the goals of this working group are to 1) establish a framework to coordinate research campaigns, as appropriate, to minimize duplication of effort and enhance synergy; 2) define what analogs are best to use for collaborative interests; and 3) facilitate interaction between discipline experts in order to have the full benefit of international expertise. To accomplish these goals, HANA is currently engaged in developing international research campaigns in ground-based analogs. Plans are being made for an international solicitation for proposals to address research of common interest to all international partners. This solicitation with identify an analog environment that will best accommodate the types of investigations requested. Once selected, studies will be integrated into a campaign and implemented at the analog site. Through these combined efforts, research beneficial to all partners will be conducted efficiently to further address human risks of space exploration.

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

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


    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…

  18. Photonic analog computing with integrated silicon waveguides

    Dong, Jianji; Zheng, Aoleng; Zhang, Xinliang


    The spectra of silicon integrated waveguides are tailored to process analog computing (i.e.,differential and integral) in optical domain with huge bandwidth.With the theory of signal and system, we design some silicon integrated devices to implement photonic differentiator and optical differential equation solver. The basic principle is to tailor the spectra of silicon integrated waveguides to meet the requirements of analog computing circuits. These analog photonic integrated circuits are very promising in future computing systems with high speed, low cost, and compact size. We also plan to employ these basic computing units in more complex computing modules.

  19. Photoresistance analog multiplier has wide range

    Hartenstein, R. G.


    Photoactivated bridge facilitates equal performance of analog multipliers over a wide frequency range. The multiplier operates from direct current to an upper frequency limited by either the light source or the closed-loop amplifier.

  20. The Analog (Computer) As a Physiology Adjunct.

    Stewart, Peter A.


    Defines and discusses the analog computer and its use in a physiology laboratory. Includes two examples: (1) The Respiratory Control Function and (2) CO-Two Control in the Respiratory System. Presents diagrams and mathematical models. (MA)

  1. An Electrical Analog Computer for Poets

    Bruels, Mark C.


    Nonphysics majors are presented with a direct current experiment beyond Ohms law and series and parallel laws. This involves construction of an analog computer from common rheostats and student-assembled voltmeters. (Author/TS)

  2. Optical analog-to-digital converter

    Vawter, G. Allen; Raring, James; Skogen, Erik J.


    An optical analog-to-digital converter (ADC) is disclosed which converts an input optical analog signal to an output optical digital signal at a sampling rate defined by a sampling optical signal. Each bit of the digital representation is separately determined using an optical waveguide interferometer and an optical thresholding element. The interferometer uses the optical analog signal and the sampling optical signal to generate a sinusoidally-varying output signal using cross-phase-modulation (XPM) or a photocurrent generated from the optical analog signal. The sinusoidally-varying output signal is then digitized by the thresholding element, which includes a saturable absorber or at least one semiconductor optical amplifier, to form the optical digital signal which can be output either in parallel or serially.

  3. Implementing neural architectures using analog VLSI circuits

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


    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...

  4. Pigeons, Rats, and Humans Show Analogous Misinformation

    Garry, Maryanne; Harper, David N


    In three experiments, we show that pigeons, rats and humans can be influenced by misleading postevent information in ways analogous to findings in the human memory distortion literature. We used a delayed matching to sample analog of the eyewitness testimony procedure from Loftus et al.(1978), and varied the length of the delay between event and exposure to post event information(PEI). We also varied the nature of PEI so that it was consistent with the event information, inconsistent, or neut...

  5. Analog VLSI model of binaural hearing

    Mead, Carver A.; Arreguit, Xavier; Lazzaro, John


    The stereausis model of biological auditory processing was proposed as a representation that encodes both binaural and spectral information in a unified framework. We describe a working analog VLSI chip that implements this model of early auditory processing in the brain. The chip is a 100 000-transistor integrated circuit that computes the stereausis representation in real time, using continuous-time analog processing. The chip receives two audio inputs, representing sou...

  6. Analogical Learning and Automated Rule Constructions



    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.

  7. AMiBA Wideband Analog Correlator

    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


    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.

  8. AMiBA Wideband Analog Correlator

    Li, Chao-Te; Kubo, Derek Y.; Wilson, Warwick; Lin, Kai-Yang; Chen, Ming-Tang; P. T. P. Ho; Chen, Chung-Cheng; Han, Chih-Chiang; Oshiro, Peter; Martin-Cocher, Pierre; Chang, Chia-Hao; Chang, Shu-Hao; Altamirano, Pablo; Jiang, Homin; Chiueh, Tzi-Dar


    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 c...

  9. AMiBA Wideband Analog Correlator

    Li, Chao-Te; Kubo, Derek Y.; 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; Proty Wu, Jiun-Huei


    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 intermediate frequency distribution, back-end 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.

  10. Low Power Analog Design in Scaled Technologies

    Baschirotto, A; Cocciolo, G; D’Amico, S; De Matteis, M; Delizia, P


    In this paper an overview on the main issues in analog IC design in scaled CMOS technology is presented. Decreasing the length of MOS channel and the gate oxide has led to undoubted advantages in terms of chip area, speed and power consumption (mainly exploited in the digital parts). Besides, some drawbacks are introduced in term of power leakage and reliability. Moreover, the scaled technology lower supply voltage requirement has led analog designers to find new circuital solution to guarantee the required performance.

  11. A review of EBMT using proportional analogies

    Somers, Harold; Dandapat, Sandipan; Naskar, Sudip Kumar


    Some years ago a number of papers reported an experimental implementation of Example Based Machine Translation (EBMT) using Proportional Analogy. This approach, a type of analogical learning, was attractive because of its simplicity; and the papers reported considerable success with the method. This paper reviews what we believe to be the totality of research reported using this method, as an introduction to our own experiments in this framework, reported in a companion paper. We report first...

  12. Automated Integrated Analog Filter Design Issues

    Karolis Kiela; Romualdas Navickas


    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...

  13. On the gravitational analog of electromagnetic induction

    Discussed are some aspects of the analogy between stationary gravitational and electromagnetic fields, in particular, the gravitational analog of the electromagnetic induction phenomenon. The point is that the field of forces influencing the test particle in the strict system of reference is similar to the field of forces influencing a charged particle in the stationary electromagnetic field. The effect proceeds from the equation of motion of a spinning extended body

  14. Analog modelling of obduction processes

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


    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

  15. Optical domain analog to digital conversion methods and apparatus

    Vawter, Gregory A


    Methods and apparatus for optical analog to digital conversion are disclosed. An optical signal is converted by mapping the optical analog signal onto a wavelength modulated optical beam, passing the mapped beam through interferometers to generate analog bit representation signals, and converting the analog bit representation signals into an optical digital signal. A photodiode receives an optical analog signal, a wavelength modulated laser coupled to the photodiode maps the optical analog signal to a wavelength modulated optical beam, interferometers produce an analog bit representation signal from the mapped wavelength modulated optical beam, and sample and threshold circuits corresponding to the interferometers produce a digital bit signal from the analog bit representation signal.

  16. Analog Signal Correlating Using an Analog-Based Signal Conditioning Front End

    Prokop, Norman; Krasowski, Michael


    This innovation is capable of correlating two analog signals by using an analog-based signal conditioning front end to hard-limit the analog signals through adaptive thresholding into a binary bit stream, then performing the correlation using a Hamming "similarity" calculator function embedded in a one-bit digital correlator (OBDC). By converting the analog signal into a bit stream, the calculation of the correlation function is simplified, and less hardware resources are needed. This binary representation allows the hardware to move from a DSP where instructions are performed serially, into digital logic where calculations can be performed in parallel, greatly speeding up calculations.

  17. Efecto de la quercetina sobre la nefrotoxicidad producida por cadmio

    A. I. Morales Martín; Vicente Sánchez; C. Santiago Sandoval; J Mª Fernández Tagarro; J.M. López Novoa; F. Pérez Barriocanal


    El incremento en la producción anual de cadmio ha favorecido que la incidencia de la intoxicación crónica por este elemento haya aumentado en los últimos años. El estrés oxidativo es uno de los mecanismos implicados en la generación del efecto tóxico, manifestándose, entre otras patologías, por una disfunción y lesión renal. La quercetina, un flavonoide muy abundante en la dieta mediterránea, es un potente antioxidante y un buen quelante de metales. Nuestro objetivo fue estudia...

  18. Efectos beneficiosos del chocolate en la salud cardiovascular

    Gómez Juaristi, Miren; L. González-Torres; Bravo, Laura; Bastida, Sara; F. J. Sánchez-Muniz


    Desde la antigüedad se ha atribuido al chocolate propiedades saludables que lo han aproximado más hacia un uso terapéutico que alimentario. El presente trabajo revisa algunos estudios relevantes de los efectos del chocolate (y sus componentes activos) sobre diferentes factores de riesgo cardiovascular y señala la necesidad de futuros estudios. El consumo de cacao/chocolate (i) incrementa la actividad antioxidante, (ii) modula la función plaquetaria e inflamación y (iii...

  19. Efecto protector de oleuropeina en inflamación intestinal

    Giner Ventura, Elisa


    La colitis ulcerosa (CU) es un desorden inflamatorio intestinal crónico que se caracteriza por la inflamación recurrente del colon. Debido a su desconocida etiología, la búsqueda de nuevos tratamientos farmacológicos está enfocada a mejorar la calidad de vida de los pacientes y reducir la inflamación. Sin embargo, aún con un amplio espectro de medicamentos, un cierto porcentaje de pacientes son resistentes a estas terapias, y además, los efectos secundarios asociados son elevados y, algunos d...

  20. El efecto spillover de la M-30 de Madrid

    López García de Leániz, Cristina; Pérez Prada, Fiamma


    Este artículo propone una metodología para medir el efecto desbordamiento o spillover que produce una infraestructura de transporte, en este caso viaria de carácter urbano (M-30), sobre los municipios limítrofes, y su impacto en la movilidad urbana y metropolitana de Madrid. Se utiliza un modelo de demanda de vehículo privado de la región de Madrid para cuantificar el número de viajes de la M-30 con origen o destino en estos municipios.

  1. Los efectos contraproducentes de los Planes de Mano Dura

    Aguilar Villamariona, Jeannette


    El presente artículo se ocupa de analizar y mostrar a la luz de las propias estadísticas oficiales el fracaso de las políticas de Mano Dura y Super Mano Dura implementadas en El Salvador en los últimos tres años, en su tarea de combatir la criminalidad y controlar el fenómeno de las pandillas. A su vez, se centra en analizar dos de los principales efectos adversos que la implementación de políticas represivas ha tenido en la inseguridad y en la violencia experimentada en ...

  2. Efectos del entrenamiento en memoria en personas mayores

    Sánchez Caro, Yolanda


    El proceso de envejecimiento lleva consigo diferentes cambios a nivel físico y cognitivo. Durante este proceso tienen lugar ciertos déficits de memoria asociados a la edad, pudiéndose mejorar el rendimiento en tareas de memoria, así como la autopercepción de la misma gracias a entrenamientos centrados en este proceso cognitivo. El objetivo de este trabajo es estudiar el efecto de un entrenamiento en memoria sobre el rendimiento objetivo de la misma y quejas subjetivas de los participantes;...




    Las hormonas adrenales, administradas inmediatamente antes o después de una tarea de aprendizaje, modulan la memoria. Este efecto varía de acuerdo al tiempo y a la intensidad con que se incrementan las hormonas. La liberación o administración de glucocorticoides inmediatamente antes o después de una tarea, facilitan la memoria. Por el contrario, la elevación o administración de glucocorticoides antes de una prueba de aprendizaje, deteriora la evocación de la información previamente adquirida....


    Paula Carrillo; María Victoria Gilli


    Se ha propuesto realizar una investigación sobre los efectos de la suplementación con creatina como ayuda ergogénica para mejorar la performance deportiva. La investigación consistió en una evaluación del consumo de creatina, en una muestra representativa de deportistas recreacionales y amateurs que concurren a gimnasios habilitados de la ciudad de Pergamino, provincia de Buenos Aires. Las investigaciones disponibles indican que la creatina puede incrementar el contenido muscular de fosfocrea...

  5. The future of vitamin D analogs

    Carlien eLeyssens


    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

  6. Natural Analogs for the Unsaturated Zone

    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

  7. Neurotoxic Alkaloids: Saxitoxin and Its Analogs

    Troco K. Mihali


    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.

  8. NaturAnalogs for the Unsaturated Zone

    A. Simmons; A. Unger; M. Murrell


    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.

  9. Analog forecasting with dynamics-adapted kernels

    Zhao, Zhizhen; Giannakis, Dimitrios


    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.

  10. Efecto de la edad y el entrenamiento sobre la memoria

    Angel M. Elgier


    Full Text Available Numerosos antecedentes muestran que el envejecimiento está asociado con el deterioro de algunas capacidades cognitivas, entre ellas la memoria. Hay evidencias que indican que las deficiencias de memoria asociadas con la edad pueden mejorarse con entrenamiento, tanto en adultos jóvenes como maduros. El objetivo de la investigación fue evaluar el efecto de la edad y el entrenamiento sobre una tarea de recuerdo de palabras, comparando un grupo de adultos jóvenes con un grupo de adultos mayores, que recibían o no entrenamiento. Los adultos jóvenes recordaron más palabras que los maduros. Asimismo, el entrenamiento produjo un incremento en la cantidad de palabras recordadas en ambos grupos etareos. Los grupos Jóvenes sin entrenamiento y Maduros con entrenamiento obtuvieron un rendimiento similar. Se discuten las implicancias clínicas del efecto del entrenamiento en adultos jóvenes y maduros.

  11. Efecto acaricida de una mezcla química

    E. Egea


    Full Text Available

    Introducción: Se investiga el efecto de una nueva mezcla química (ATLASAC para el control de ácaros del polvo doméstico, microorganismos cosmopolitas que conviven con el hombre, reconocidos como importante fuente de alergenos y la principal causa de exacerbación de las enfermedades alérgicas. En el medio ambiente de los hogares colombianos se conoce por reportes científicos la prevalencia de varias especies comunes en otros países: Dermatophagoides pteronyssinus, D. Farinae, Blomia tropicales, etc, asociados con asma y/o rinitis. Por todo ello, en el medio ambiente residencial del paciente es importante establecer medidas locativas tendientes a evitar la exposición y el control químico para reducir o eliminar la fuente de alergenos, en especial, los ácaros. Un recurso fácil de aplicar son los acaricidas, los cuales varían en el grado de efectividad y tiempo de protección. En nuestro medio no se tienen productos aprobados como acaricidas. Por tal motivo, esta investigación pretende llenar un vacío en el medio colombiano con una mezcla química con efecto acaricida, en especial sobre aquellos implicados con las enfermedades alérgicas.

    Metodología: Se seleccionaron 25 pacientes definidos por historia clínica como alérgicos y 50 voluntarios que por pruebas cutáneas se descartó sensibilización a ácaros. Inmediatamente después del ingreso se hicieron muestreos para determinar la presencia de ácaros del polvo doméstico y fundamentalmente para obtener cultivos puros.

    Resultados preliminares: 100 ácaros de

  12. Analogical reasoning for reliability analysis based on generic data

    Kozin, Igor O


    The paper suggests using the systemic concept 'analogy' for the foundation of an approach to analyze system reliability on the basis of generic data, describing the method of structuring the set that defines analogical models, an approach of transition from the analogical model to a reliability model and a way of obtaining reliability intervals of analogous objects.

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

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


    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…

  14. Analog Forecasting with Dynamics-Adapted Kernels

    Zhao, Zhizhen


    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 ...

  15. Electronic devices for analog signal processing

    Rybin, Yu K


    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...

  16. Analog pipeline readout for ATLAS calorimetry

    This paper presents the design and prototype testing of an analog pipeline readout module suitable for readout of the LAr calorimetry at the large hadron collider. The design has been driven by the readout requirements of the ATLAS electromagnetic liquid argon calorimeter and the ATLAS trigger design parameters. The results indicate that an analog pipeline readout system meeting the ATLAS requirements can be built using our modules. The SCA-chip employed has resolution approaching 13-bits (using the full range of the SCA) and can achieve a 16-bit dynamic range using a dual-range scheme. The module is based on switched capacitor array chips. A brief description of the design of the pipeline controller development, that will enable the SCA readout system to run as a deadtimeless analog RAM, is also given. (orig.)

  17. On Lovelock analogs of the Riemann tensor

    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)


    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.)

  18. Biosynthesis of amphetamine analogs in plants.

    Hagel, Jillian M; Krizevski, Raz; Marsolais, Frédéric; Lewinsohn, Efraim; Facchini, Peter J


    Amphetamine analogs are produced by plants in the genus Ephedra and by Catha edulis, and include the widely used decongestants and appetite suppressants pseudoephedrine and ephedrine. A combination of yeast (Candida utilis or Saccharomyces cerevisiae) fermentation and subsequent chemical modification is used for the commercial production of these compounds. The availability of certain plant biosynthetic genes would facilitate the engineering of yeast strains capable of de novo pseudoephedrine and ephedrine biosynthesis. Chemical synthesis has yielded amphetamine analogs with myriad functional group substitutions and diverse pharmacological properties. The isolation of enzymes with the serendipitous capacity to accept novel substrates could allow the production of substituted amphetamines in synthetic biosystems. Here, we review the biology, biochemistry and biotechnological potential of amphetamine analogs in plants. PMID:22502775

  19. Landauer Bound for Analog Computing Systems

    Diamantini, M Cristina; Trugenberger, Carlo A


    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. Doing mathematics convention, subject, calculation, analogy

    Krieger, Martin H


    This book discusses some ways of doing mathematical work and the subject matter that is being worked upon and created. It argues that the conventions we adopt, the subject areas we delimit, what we can prove and calculate about the physical world, and the analogies that work for mathematicians - all depend on mathematics, what will work out and what won't. And the mathematics, as it is done, is shaped and supported, or not, by convention, subject matter, calculation, and analogy. The cases studied include the central limit theorem of statistics, the sound of the shape of a drum, the connection

  1. Space flight nutrition research: platforms and analogs

    Smith, Scott M.; Uchakin, Peter N.; Tobin, Brian W.


    Conducting research during actual or simulated weightlessness is a challenging endeavor, where even the simplest activities may present significant challenges. This article reviews some of the potential obstacles associated with performing research during space flight and offers brief descriptions of current and previous space research platforms and ground-based analogs, including those for human, animal, and cell-based research. This review is intended to highlight the main issues of space flight research analogs and leave the specifics for each physiologic system for the other papers in this section.

  2. Associative Pattern Recognition In Analog VLSI Circuits

    Tawel, Raoul


    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.

  3. One higher dimensional analog of jet schemes

    Yuen, Cornelia


    We develop the theory of truncated wedge schemes, a higher dimensional analog of jet schemes. We prove some basic properties and give an irreducibility criterion for truncated wedge schemes of a locally complete intersection variety analogous to Musta\\c{t}\\v{a}'s for jet schemes. We show that the reduced subscheme structure of a truncated wedge scheme of any monomial scheme is itself a monomial scheme in a natural way by explicitly describing generators of each of the minimal primes of any tr...

  4. Discrete analog computing with rotor-routers.

    Propp, James


    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. PMID:20887076

  5. Analog circuit design for communication SOC

    Tu, Steve Hung-Lung


    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

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

    van de Plassche, R.J.


    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

  7. El efecto de la estancia postdoctoral en la productividad científica

    García-Romero, Antonio


    En este trabajo se estudia el efecto que tiene sobre la productividad científica, la realización de una estancia postdoctoral. En primer lugar, se presenta una revisión de la literatura sobre formación de investigadores. En segundo lugar, se estima un modelo basado en la Teoría de Capital Humano para explicar dicho efecto. Los resultados muestran que la productividad es debida tanto a la habilidad de los doctores como a la estancia realizada, si bien el primer efecto es del orden de siete vec...

  8. Efectos reales de la política fiscal en Colombia: 1990-2007

    Henry Laverde


    Full Text Available La evidencia internacional muestra que la actividad económica se veafectada por los choques de la política fiscal. En este trabajo se caracterizan los efectos dinámicos del gasto y los ingresos del Gobierno nacional colombiano sobre el producto interno bruto (PIB y la demanda agregada para el periodo 1990-2007. Para ello se utiliza un modelo estructural de vectores autorregresivos (SVAR con información trimestral. Los resultados evidencian los efectos keynesianos tanto de la tributación como del gasto gubernamental y de sus componentes (consumo e inversión, aunque sus efectos son de bajapersistencia.

  9. The GMO-Nanotech (Dis)Analogy?

    Sandler, Ronald; Kay, W. D.


    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…

  10. Analog circuit design designing waveform processing circuits

    Feucht, Dennis


    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.

  11. A high-speed analog neural processor

    Masa, Peter; Hoen, Klaas; Wallinga, Hans


    Targeted at high-energy physics research applications, our special-purpose analog neural processor can classify up to 70 dimensional vectors within 50 nanoseconds. The decision-making process of the implemented feedforward neural network enables this type of computation to tolerate weight discretiza

  12. Analog Optical Computing Primitives in Silicon Photonics

    Jiang, Yunshan; Jalali, Bahram


    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  13. Analog optical computing primitives in silicon photonics

    Jiang, Yunshan; DeVore, Peter T. S.; Jalali, Bahram


    Optical computing accelerators may help alleviate bandwidth and power consumption bottlenecks in electronics. We show an approach to implementing logarithmic-type analog co-processors in silicon photonics and use it to perform the exponentiation operation. The function is realized by exploiting nonlinear-absorption-enhanced Raman amplification saturation in a silicon waveguide.

  14. Biological Analogs for Language Contact Situations

    Seliger, Herbert W.


    This article proposes that language contact can be best understood if the entire range of such situations from second language learning to evolution of dialects and creoles is studied within a framework analogical to the symbiosis of living organisms. Language contact is viewed in terms of dynamic evolutionary stages. (CHK)

  15. A Mechanical Analogy for Ohm's Law.

    do Couto Tavares, Milton; And Others


    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)

  16. Formal analogies in physics teacher education

    Avelar Sotomaior Karam, Ricardo; Ricardo, Elio


    . Despite 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...

  17. Plasma analog of particle-pair production

    It is shown that the plasma axial shear flow instability satisfies the Klein-Gordon equation. The plasma instability is then shown to be analogous to spontaneous particle-pair production when a potential energy is present that is greater than twice the particle rest mass energy. Stability criteria can be inferred based on field theoretical conservation laws. (UK)

  18. Radiation Behavior of Analog Neural Network Chip

    Langenbacher, H.; Zee, F.; Daud, T.; Thakoor, A.


    A neural network experiment conducted for the Space Technology Research Vehicle (STRV-1) 1-b launched in June 1994. Identical sets of analog feed-forward neural network chips was used to study and compare the effects of space and ground radiation on the chips. Three failure mechanisms are noted.

  19. Bootstrapped Low-Voltage Analog Switches

    Steensgaard-Madsen, Jesper


    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...

  20. Efecto invernadero o el acto de poseer un cuerpo

    Daniela Renjel Encinas


    Full Text Available Este trabajo aborda la construcción discursiva de la enfermedad terminal como antesala de la muerte y momento culminante de creación y belleza siniestra. El mal es el camino hacia la posesión del cuerpo; el deterioro, la vía de conocimiento y revelación que se opone a la nada, la antagonista de la belleza. Con Efecto invernadero, Bellatin abre la posibilidad de concebir la enfermedad como un imperativo de creación de la obra más importante, el momento final de la propia vida, mediante una escritura que se pule con los años, a manera de un juego cuyas reglas incluyen lo intocable de la vida.

  1. Efectos derrame interestatales y transfronterizos de la red de carreteras: Un estudio para México

    Inmaculada C. Álvarez Ayuso


    Full Text Available El objetivo de esta investigación es identificar la existencia de efectos derrame de la infraestructura carretera nacional y transfronteriza de Estados Unidos sobre la producción en México, a través de la implementación de un modelo de fronteras estocásticas. Para ello, se han elaborado indicadores espaciales que capturan estos efectos y que recogen la influencia de las entidades federativas contiguas a cada una de ellas. Los resultados muestran que tanto las carreteras nacionales como las transfronterizas generan un efecto favorable para la producción, reduciendo la ineficiencia técnica estatal, generando efectos derrame entre las entidades federativas contiguas.

  2. Efectos del entrenamiento de carrera en el rendimiento en ciclismo. Un modelo de entrenamiento del duathlon

    Chavarren Cabrero, Javier


    [ES] El duathlon es una disciplina deportiva que combina carrera y ciclismo. Se analiza aquí una de las posibles alternativas de entrenamiento, describiendo sus efectos sobre el rendimiento en competición.

  3. Efecto de los antipsicóticos sobre la homeostasis intracelular del colesterol

    Canfrán Duque, Alberto


    Los antipsicóticos son aminas anfipáticas que se utilizan ampliamente para el tratamiento de ciertos trastornos psiquiátricos por su capacidad de inhibir los receptores D2. Desafortunadamente, algunos de los más utilizados, particularmente los de segunda generación (SGA), producen efectos metabólicos indeseados como ganancia de peso, hipertrigliceridemia e hiperglucemia, con incremento del riesgo cardiovascular. Para explorar los mecanismos potencialmente implicados en estos efectos secundari...

  4. ??Qu?? experimentamos al tomar t??? Estudio cualitativo y efecto farmacol??gico de sus componentes

    Ramos Mart??nez, T.; Campo y Matilla, M.M. del; Slowing Barillas, K.


    RESUMEN: Al igual que otras plantas, la Camellia sinensis posee efectos sobre nuestro organismo. La costumbre actual del ???afternoon tea??? en Inglaterra, y el consumo de t?? como bebida placentera (Nestea, Trina t?????) ha hecho que sus efectos farmacol??gicos pasen a un segundo plano sin percatarnos del beneficio que nos aporta. Este estudio pretende mostrar lo que ???desconocemos??? sobre ??l. OBJETIVO: Conocer los principales componentes del t??, su control de calidad y su...

  5. Efectos visuales: desarrollo y evolución a lo largo de la historia del cine



    A lo largo de la historia del cine se han utilizado multitud de efectos visuales con el objetivo de asombrar, reducir la peligrosidad o disminuir los costes de representación de algunas escenas. Ante el crecimiento exponencial de los efectos visuales digitales (VFX), este trabajo pretende indagar respecto a las transformaciones tecnológicas que han ido convirtiendo estas formas de trabajo puramente analógicas, al entorno computarizado. De igual forma, comprender la fase prim...

  6. Analog Computation by DNA Strand Displacement Circuits.

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


    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. PMID:27363950

  7. Optimal neural computations require analog processors

    Beiu, V.


    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).


    The Anglo-Australian Planet Search has now accumulated 12 years of radial-velocity data with long-term instrumental precision better than 3 m s-1. In this paper, we expand on earlier simulation work, to probe the frequency of near-circular, long-period gas-giant planets residing at orbital distances of 3-6 AU-the so-called Jupiter analogs. We present the first comprehensive analysis of the frequency of these objects based on radial-velocity data. We find that 3.3% of stars in our sample host Jupiter analogs; detailed, star-by-star simulations show that no more than 37% of stars host a giant planet between 3 and 6 AU.

  9. Observing spin optodynamical analog of cavity optomechanics

    Gerber, Justin; Kohler, Jonathan; Spethmann, Nicolas; Schreppler, Sydney; Stamper-Kurn, Dan


    Cavity Optomechanics has been realized in many diverse systems and led to many interesting results such as ponderomotive squeezing of light, beyond-SQL measurement sensitivity, and squeezing of mechanical oscillators. Optical cavities also allow sensitive measurements of the spin of an atomic ensemble. It has been proposed to utilize this sensitivity to realize an analog of optomechanics by measuring the precession of small excitations of a spin-oscillator around a transverse magnetic field. I will present our recent work in which we realize optomechanical analogs in our system such as cavity-assisted cooling and amplification and optical spring shifts. In addition, the presence of a high-energy `ground state' of the spin oscillator allows the realization of an effective negative mass oscillator which is demonstrated by an inverted sideband asymmetry. In our ongoing work we attempt to realize coherent quantum noise cancelation by coupling spin oscillation with mechanical oscillation.

  10. High resolution tomography using analog coding

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  11. An analogy strategy for transformation optics

    We introduce an analogy strategy to design transformation optical devices. Based on the similarities between field lines in different physical systems, the trajectories of light can be intuitively determined to curve in a gentle manner, and the resulting materials are isotropic and nonmagnetic. Furthermore, the physical meaning of the analogue problems plays a key role in the removal of dielectric singularities. We illustrate this approach by creating two designs of carpet cloak and a collimating lens as representative examples in two- and three-dimensional spaces, respectively. The analogy strategy not only reveals the intimate connections between different physical disciplines, such as optics, fluid mechanics and electrostatics, but also provides a heuristic pathway to designing advanced photonic systems

  12. Analog data transmission via fiber optics

    In the SLAC Linear Collider Detector (SLD), as in most high-energy particle detectors, the electromagnetic noise environment is the limiting factor in electronic readout performance. Front-end electronics are particulary susceptible to electromagnetic interference (EMI), and great care has been taken to minimize its effects. The transfer of preprocessed analog signals from the detector environs, to the remote digital processing electronics, by conventional means (via metal conductors), may ultimately limit the performance of the system. Because it is highly impervious to EMI and ground loops, a fiber-optic medium has been chosen for the transmission of these signals. This paper describes several fiber-optic transmission schemes which satisfy the requirements of the SLD analog data transmission

  13. HAPS, a Handy Analog Programming System

    Højberg, Kristian Søe


    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 minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS. The article describes the principles of HAPS...... and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing....

  14. Analog fault diagnosis by inverse problem technique

    Ahmed, Rania F.


    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.

  15. Causas, efectos y políticas para prevenir el efecto rebote de la modernización de regadíos

    Gutiérrez-Martín, Carlos; Berbel, Julio


    La existencia de un posible efecto rebote de las medidas de ahorro de agua que lleve a un mayor consumo tiene un cierto carácter novedoso en la política de aguas, y la Unión Europea quiere apostar por la herramienta del precio del agua como solución al posible problema. En nuestra opinión, el conocimiento sobre el efecto rebote no es suficiente en este momento para apostar por un único instrumento hasta que no se conozca con la debida profundidad el fenómeno. Este documento trata de revisar l...

  16. Electromagnetotoroid Structures and their Hydrodynamic Analogs

    Pinheiro, Mario J


    We introduce the concept of an electromagnetotoroid in astrophysics, and explore its role in polar jets. This model represents the onset of Abraham's force driven by some external source, for example, the infall of gas towards a star. The Abraham's force term is analogous to the Magnus force, and thus represents the formation of electromagnetic vortex structures in the fabric of space-time. In principle, the proposed toroidal field structure can also provide force spaceship propulsion.

  17. Interference Alignment with Analog Channel State Feedback

    Ayach, Omar El; Heath Jr, Robert W.


    Interference alignment (IA) is a multiplexing gain optimal transmission strategy for the interference channel. While the achieved sum rate with IA is much higher than previously thought possible, the improvement often comes at the cost of requiring network channel state information at the transmitters. This can be achieved by explicit feedback, a flexible yet potentially costly approach that incurs large overhead. In this paper we propose analog feedback as an alternative to limited feedback ...

  18. Pyrrolidine nucleotide analogs with a tunable conformation

    Poštová Slavětínská, Lenka; Rejman, Dominik; Pohl, Radek


    Roč. 10, Aug 22 (2014), s. 1967-1980. ISSN 1860-5397 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : conformation * NMR * nucleic acids * nucleotide analog * phosphonic acid * pseudorotation * pyrrolidine Subject RIV: CC - Organic Chemistry Impact factor: 2.762, year: 2014

  19. Quantum Electric Circuits Analogous to Ballistic Conductors

    Dragoman, Daniela


    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...

  20. The 2012 Moon and Mars Analog Mission

    Graham, Lee


    The 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were completed on Mauna Kea volcano in Hawaii in July 2012. The investigations were conducted on the southeast flank of the Mauna Kea volcano at an elevation of approximately 11,500 ft. This area is known as "Apollo Valley" and is in an adjacent valley to the Very Large Baseline Array dish antenna.

  1. SOI design analog, memory and digital techniques

    Marshall, Andrew


    Preface. Acknowledgements. 1. Overview. 2. SOI Materials. 3. Components. 4. SOI Modeling. 5. Layout for SOI. 6. Static SOI Design. 7. Dynamic SOI Design. 8. SOI SRAMs. 9. SOI DRAMs. 10. SOI Analog Design. 11. Global Design Issues. 12. Low Power Design. 13. SOI in Development. Appendix 1: Internet Sites (issue 1.0). Appendix 2: Trade Mark / Technology Information (issue 1.0). Index. About the Authors.

  2. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    Shi Ke; Arlin G. Cameron; Wei Wang


    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 occur...

  3. Survey of Evaluated Isobaric Analog States

    MacCormick, M., E-mail: [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)


    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.

  4. OpenModelica for Analog IC Design

    Malo Cid, David


    Modelica is a language supported by Modelica Association. It is a non-proprietary, object-oriented, equation based language to conveniently model complex physical. OpenModelica is an open source environment for the Modelica language supported by Open Source Modelica Consortium (OSMC). The aim of this thesis is the development of a library of models and components for design and simulation of analog integrated circuits and an OMNotebook-based tutorial for an academic purpose as a design tool f...

  5. The exoplanets analogy to the Multiverse

    Kinouchi, Osame


    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 exopla...

  6. Biomedical sensor design using analog compressed sensing

    Balouchestani, Mohammadreza; Krishnan, Sridhar


    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. Synthesis and Biological Evaluation of Paclitaxel Analogs

    Baloglu, Erkan


    The complex natural product paclitaxel (Taxol®), first isolated from Taxus brevifolia, is a member of a large family of taxane diterpenoids. Paclitaxel is extensively used for the treatment of solid tumors, particularly those of the breasts and ovaries. In order to obtain additional information about the mechanism of action of paclitaxel and the environment of the paclitaxel-binding site, several fluorescent analogs of paclitaxel were synthesized, and thei...

  8. An introduction to analog and digital communications

    Haykin, Simon


    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.

  9. Controller implementation using analog reconfigurable hardware (FPAA)

    Fonseca, Paulo Jorge Rodrigues da


    This Thesis has the main target to make a research about FPAA/dpASPs devices and technologies applied to control systems. These devices provide easy way to emulate analog circuits that can be reconfigurable by programming tools from manufactures and in case of dpASPs are able to be dynamically reconfigurable on the fly. It is described different kinds of technologies commercially available and also academic projects from researcher groups. These technologies are very recent and...

  10. Difficulties in constructing Bose analogs to supergravity

    An alternative to the usual fermionic supersymmetry transformations is discussed, namely bosonic ones in which the particle helicities are changed by an integral multiple of h/2π. No matter how such transformations are carried out, it appears that the road to a local supersymmtric analog to supergravity is closed, either because no gauge field of the required rank to couple with the supercurrent exists, or because the non-interacting action is already locally invariant, and hence the supercurrent vanishes identically. (Auth.)

  11. Priming Analogical Reasoning with False Memories

    Howe, M. L.; Garner, S. R.; Threadgold, E.; Ball, L. J.


    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 mem...

  12. Analog "neuronal" networks in early vision

    Koch, C; Marroquin, J; Yuille, A.


    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be "solved" by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the...

  13. Analog controllers using digital stochastic logic

    Quero Reboul, José Manuel; S. L. Toral; García Ortega, Juan de la Cruz; García Franquelo, Leopoldo


    Stochastic logic is based on digital processing of a random pulse stream, where the information is codified as the probability of a high level in a finite sequence. The probability of the pulse stream codifies a continuous time variable. Subsequently, this pulse stream can be digitally processed to perform analog operations. In this paper we propose a stochastic approach to the digital implementation of complex controllers. This is approach allows for the realization of the controllers, and A...

  14. Analog gravity from field theory normal modes?

    Barcelo, Carlos; Liberati, Stefano; Visser, Matt


    We demonstrate that the emergence of a curved spacetime ``effective Lorentzian geometry'' is a common and generic result of linearizing a field theory around some non-trivial background. This investigation is motivated by considering the large number of ``analog models'' of general relativity that have recently been developed based on condensed matter physics, and asking whether there is something more fundamental going on. Indeed, linearization of a classical field theory (a field theoretic ...

  15. Backtracking quantum trajectories with analog feedback

    de Lange*, G.; Ristè*, D.; Tiggelman, M. J.; Eichler, C.; Tornberg, L.; Johansson, G.; Wallraff, A.; Schouten, R. N.; Dicarlo, L.


    Circuit quantum electrodynamics offers a nearly ideal platform for the fundamental study of continuous quantum measurement. A nondemolition measurement of a superconducting qubit can be performed via homodyne detection of microwave transmission through a dispersively coupled cavity. By boosting the homodyne signal with a nearly noiseless phase-sensitive parametric amplifier, we experimentally show that a form of measurement backaction, consisting of stochastic quantum phase kicks on the measured qubit, is highly correlated with the fluctuations in the continuous homodyne record. We demonstrate a real-time analog feedback scheme that counteracts these phase kicks and thereby reduces measurement-induced dephasing. We develop a numerical optimization technique to overcome the bandwidth limitations of the amplification chain and provide a theoretical model for the optimization result. A quantum efficiency of 50% is extracted for the complete analog feedback loop. Finally, we discuss the integration of this analog feedback technique to improve performance in our recent demonstration of entanglement by dispersive parity measurement. *equal contribution. Research funded by NWO and the EU projects SOLID and SCALEQIT.


    Nihar Athreyas


    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 the highly computational Normalized Cross Correlation algorithm is implemented. We propose two novel modifications to the algorithm and a new imaging architecture which, significantly reduces the computation time.

  17. Theory of analogous force on number sets

    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 yields 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. (author)

  18. Analog "neuronal" networks in early vision.

    Koch, C; Marroquin, J; Yuille, A


    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be "solved" by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the cost function is nonquadratic, raising the question of designing efficient algorithms for computing the optimal solution. Recently, Hopfield and Tank [Hopfield, J. J. & Tank, D. W. (1985) Biol. Cybern. 52, 141-152] have shown that networks of nonlinear analog "neurons" can be effective in computing the solution of optimization problems. We show how these networks can be generalized to solve the nonconvex energy functionals of early vision. We illustrate this approach by implementing a specific analog network, solving the problem of reconstructing a smooth surface from sparse data while preserving its discontinuities. These results suggest a novel computational strategy for solving early vision problems in both biological and real-time artificial vision systems. PMID:3459172

  19. Analog ``Neuronal'' Networks in Early Vision

    Koch, Christof; Marroquin, Jose; Yuille, Alan


    Many problems in early vision can be formulated in terms of minimizing a cost function. Examples are shape from shading, edge detection, motion analysis, structure from motion, and surface interpolation. As shown by Poggio and Koch [Poggio, T. & Koch, C. (1985) Proc. R. Soc. London, Ser. B 226, 303-323], quadratic variational problems, an important subset of early vision tasks, can be ``solved'' by linear, analog electrical, or chemical networks. However, in the presence of discontinuities, the cost function is nonquadratic, raising the question of designing efficient algorithms for computing the optimal solution. Recently, Hopfield and Tank [Hopfield, J. J. & Tank, D. W. (1985) Biol. Cybern. 52, 141-152] have shown that networks of nonlinear analog ``neurons'' can be effective in computing the solution of optimization problems. We show how these networks can be generalized to solve the nonconvex energy functionals of early vision. We illustrate this approach by implementing a specific analog network, solving the problem of reconstructing a smooth surface from sparse data while preserving its discontinuities. These results suggest a novel computational strategy for solving early vision problems in both biological and real-time artificial vision systems.

  20. Radiolabeled somatostatin analogs: Biodistribution and pharmacokinetics

    Different somatostatin analogs labeled with iodine-123 or indium-111 are currently used for the scintigraphic in vivo detection of somatostatin receptor expression by neuroendocrine tumors. The general features of the biodistribution of iodine-123-Tyr3-octreotide are the rapid clearance from the circulation and the predominantly hepatobiliary excretion. This pathway of excretion leads to a considerable amount of activity in the bowels and thus may compromise the diagnostic reliability of somatostatin receptor scintigraphy in gastroentereopancreatic tumors. In contrast, up to 85% of the applied dose of indium-111 labeled pentreotide is cleared from the circulation via the kidneys. High receptor density and affinity as well as the small molecular size of the labeled somatostatin analogs are most likely responsible for the observed rapid tumor visualization within a few hours after intravenous application of the radiopharmaceuticals. Continuous treatment with somatostatin analogs changes the biodistribution of indium-111 pentetreotide, but the diagnostic reliability of somatostatin receptor scintigraphy is not necessarily compromised under these therapeutic conditions. (orig./MG)

  1. Automated Generation of Cross-Domain Analogies via Evolutionary Computation

    Baydin, Atilim Gunes; Ontanon, Santiago


    Analogy plays an important role in creativity, and is extensively used in science as well as art. In this paper we introduce a technique for the automated generation of cross-domain analogies based on a novel evolutionary algorithm (EA). Unlike existing work in computational analogy-making restricted to creating analogies between two given cases, our approach, for a given case, is capable of creating an analogy along with the novel analogous case itself. Our algorithm is based on the concept of "memes", which are units of culture, or knowledge, undergoing variation and selection under a fitness measure, and represents evolving pieces of knowledge as semantic networks. Using a fitness function based on Gentner's structure mapping theory of analogies, we demonstrate the feasibility of spontaneously generating semantic networks that are analogous to a given base network.

  2. Functional DNA: Teaching Infinite Series through Genetic Analogy

    Kowalski, R. Travis


    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…


    Fernando Ubiratan Da Silveira


    Full Text Available El aumento de la temperatura corporal y la aparición de la sudoración son dos respuestas normales a la actividad física. Sin embargo, la deshidratación y la hipertermia que frecuentemente acompañan el entrenamiento deportivo y a la competición, son las causas más comunes y al mismo tiempo evitables de la fatiga prematura entre los atletas (Murray, 1996. La deshidratación contribuye a la hipertermia reduciendo la capacidad del organismo de perder calor, y aún bajos niveles de deshidratación de tan sólo un 2% del peso corporal perdido, pueden perjudicar el rendimiento físico (Maughan, 2003; Murray, 1996. Los efectos de la deshidratación sobre variables anaeróbicas no son muy claros, debido a los diferentes porcentuales y métodos de deshidratación utilizados en las investigaciones. Por eso, la presente revisión de literatura propone un análisis de los efectos de la deshidratación sobre el rendimiento y metabolismo anaeróbico bajo la organización según tres distintos modelos experimentales: 1. métodos de deshidratación pasiva; 2. métodos de deshidratación activa; 3. método de deshidratación mixto. Así como ocurre en el rendimiento aeróbico, las diferencias en los resultados del rendimiento anaeróbico parecen estar relacionados con algunos factores como: la magnitud de cambio en el peso corporal, el tiempo en que los sujetos estuvieran bajo proceso de deshidratación, las pruebas utilizadas para medir las variables anaeróbicas, los métodos de deshidratación y principalmente si hubo combinación de estos métodos.




    Full Text Available En gran parte de la comunidad científica, así como del ámbito jurídico, al tratar del embrión no nacido, está vigente el criterio según el cual hay que definir el embarazo como el período que comprende sólo desde la implantación hasta el nacimiento natural. Esto lleva consigo otras novedades; por ejemplo, la redefinición de aborto como la eliminación del embrión sólo en ese período, o la extensión de la anticoncepción a cualquier medio que impida la unión entre los gametos como consecuencia de una relación íntima, o también que elimine el producto de la concepción antes de su implantación. De modo que la industria farmacéutica está lanzando al mercado, bajo el nombre de anticonceptivos, productos que actúan también mediante un mecanismo antiimplantatorio. Este hecho tiene grandes repercusiones éticas con relación al respeto del embrión, que obligan a reflexionar acerca de la valoración moral de la prescripción, dispensación y uso de estos medios. Ahora bien, ¿cuáles de los medios contraceptivos actualmente presentes en el mercado incluyen un efecto antiimplantatorio?, ¿qué mecanismos contribuyen a su acción farmacológica y en qué medida lo hacen? Esto es lo que hemos estudiado en este artículo, basándonos en la bibliografía científica disponible. Aunque no ha sido una tarea sencilla, puesto que los resultados aportados por la literatura varían mucho, se ha tratado de ofrecer una conclusión bastante precisa. Básicamente hemos cumplido un doble objetivo: actualizar y completar los estudios —pocos, parciales o lejanos en el tiempo— que tenían este mismo objeto; y ofrecer una valoración ética respecto al respeto de la vida naciente del uso de los anticonceptivos hormonales que pueden tener efecto antiimplantatorio.

  5. An optimized analog to digital converter for WLAN analog front end

    A 10 bit 80 MSPS analog to digital converter optimized for WLAN analog front end is presented. In contrast to conventional 1.5 bit pipeline architecture, four optimized multi-bit multiply digital to analog converter stages are implemented. An on-chip low-noise reference buffer is proposed for SoC integration purposes, and a wide-bandwidth wide swing sample and hold amplifier is also presented for achieving a good dynamic range. The converter was fabricated in 0.18 μm 1P6M CMOS technology, and the core area occupies approximately 0.85 mm2. Measured results show that with an 11 MHz input signal, it provides a 9.4 bit effective number of bits and a 72 dBc spurious frequency dynamic range when sampled at 80 MHz. (semiconductor integrated circuits)

  6. Neurociencia y bilingüismo: efecto del primer idioma

    Germary Díaz-Sánchez


    Full Text Available Desde la perspectiva neurobiológica, en este trabajo abordamos los efectos del idioma materno sobre el aprendizaje de una segunda lengua. Aunque existen investigaciones en diferentes países sobre este problema, pocas tratan el enfoque de la neurobiología y, menos aún, cuando se trata del español como idioma materno. Para la investigación se recopiló literatura descriptiva y experimental, con el fin de obtener los datos necesarios para alcanzar los objetivos; se realizó un metaanálisis cualitativo de los datos obtenidos, utilizando tablas de correlación. Los datos reflejaron que la adquisición de un segundo idioma siempre va a estar mediatizada por los esquemas ya establecidos del primer idioma y que existen aspectos neurobiológicos que subyacen a algunos mecanismos de interferencia y a la adquisición de un segundo lenguaje. Además, encontramos que, mientras más similares sean los idiomas, los mecanismos neurales subyacentes facilitan la transferencia del uno al otro.

  7. Efecto del bioestimulante fitomas E en cultivos seleccionados

    José Villar


    Full Text Available FitoMas E es un bioestimulante derivado de la industria azucarera obtenido y desarrollado en el ICIDCA, que ejerce una gran influencia en el desarrollo de las plantas de cultivo. El efecto antiestrés de este producto se manifiesta en una mejora fisiológica global del estado de la planta. En este trabajo se presentan los resultados sobre la floración y el rendimiento en los cultivos de tomate (Licopersicum sculentus variedad Amalia y pepino (Cucumis sativus variedad SS-5 bajo manejo agroecológico. El pepino se plantó en un suelo con indicadores de fertilidad aceptables, pero saturado con valores cercanos a la salinidad. Por su parte, el tomate fue plantado en un suelo con contenido satisfactorio de fósforo y potasio para este cultivo pero bajo en materia orgánica (2.09 %. Se reportan incrementos de 118 % en el número de flores en tomate con 0.7 l/ha de FitoMas E y en el pepino de 147 % y 156 %, respectivamente, para las flores masculinas y femeninas con dosis de 0.2 l/ha del producto. Por otra parte, los incrementos de rendimientos fueron de 333 % en tomate y de 145 % en pepino.

  8. Historical financial analogies of the current crisis

    Andrada-Félix, Julián; Fernández Rodríguez, Fernando; Sosvilla Rivero, Simón Javier


    Este trabajo intenta arrojar luz sobre las analogías históricas de la crisis actual. Para ello se compara la distribución de los rendimientos del Índice Dow Jones Industrial Average durante un período de 769 días (del 15 de septiembre de 2008, la quiebra de Lehman Brothers, hasta septiembre de 2011), con todas las distribuciones históricas posibles de rendimientos calculados con una ventana móvil de 769 días desde el 2 de enero de 1900 al 12 de septiembre de 2008. Mediante el uso de un contra...

  9. Design of analog circuits through symbolic analysis

    Fakhfakh, Mourad; V Fernández, Francisco


    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

  10. High fluid intelligence and analogical reasoning

    Preusse, Franziska


    Hitherto, previous studies on the cerebral correlates of fluid intelligence (fluIQ) used tasks that did not exclusively demand fluIQ, or were restricted to participants of average fluIQ (ave-fluIQ) solving intelligence test items of varying difficulty, thus not allowing assumptions on interindividual differences in fluIQ. Geometric analogical reasoning (GAR) demands fluIQ very purely and thus is an eligible approach for research on interindividual differences in fluIQ. In a first study, we ...

  11. An optical analog of quantum optomechanics

    Rodríguez-Lara, B M


    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.

  12. Performance of the Analog Moving Window Detector

    Hansen, V. Gregers


    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 of the...... antenna. An expression for the false alarm rate of the detector is first derived and evaluated numerically. The detection performance and angular accuracy are next determined in a direct Monte Carlo simulation of the detector on a digital computer for both no fading and pulse-to-pulse Rayleigh fading...

  13. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    Watson, Christine E; Chatterjee, Anjan


    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. PMID:21982934

  14. Analogy perception applied to seven tests of word comprehension

    Turney, Peter D


    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...

  15. Comparison between analog and digital filters

    Zoltan Erdei


    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.

  16. Beryllium Abundances of Solar-Analog Stars

    Takeda, Yoichi; Honda, Satoshi; Kawanomoto, Satoshi; Ando, Hiroyasu; Sakurai, Takashi


    An extensive beryllium abundance analysis was conducted for 118 solar analogs (along with 87 FGK standard stars) by applying the spectrum synthesis technique to the near-UV region comprising the Be II line at 3131.066 A, in an attempt to investigate whether Be suffers any depletion such as the case of Li showing a large diversity. We found that, while most of these Sun-like stars are superficially similar in terms of their A(Be) (Be abundances) around the solar value within ~ +/- 0.2dex, 4 out of 118 samples turned out strikingly Be-deficient (by more than ~2 dex) and these 4 stars belong to the group of lowest v_e sin i (projected rotation velocity). Moreover, even for the other majority showing an apparent similarity in Be, we can recognize a tendency that A(Be) gradually increases with an increase in v_e sin i. These observational facts suggest that any solar analog star (including the Sun) generally suffers some kind of Be depletion during their lives, where the rotational velocity (or the angular momentu...

  17. Isolation and characterization of soybean NBS analogs


    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.

  18. Efficient Analog Circuits for Boolean Satisfiability

    Yin, Xunzhao; Varga, Melinda; Ercsey-Ravasz, Maria; Toroczkai, Zoltan; Hu, Xiaobo Sharon


    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...

  19. AFEII Analog Front End Board Design Specifications

    Rubinov, Paul; /Fermilab


    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.

  20. The exoplanets analogy to the Multiverse

    Kinouchi, Osame


    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...

  1. Developing Fluorescent Hyaluronan Analogs for Hyaluronan Studies

    Shi Ke


    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.

  2. Analog to digital control system replacement projects

    Problem Statement: Numerous Control Systems within Operating Nuclear Units are nearing or at the end of their useful life. These systems are typically Analog in design, installed and commissioned during original construction dates. Problems associated with these aging system which are plaging Nuclear Operators are Obsolescence, Inadequate Spares, Complexity in Troubleshooting large hardwired systems, Eroding Experience and Device Failures leading to safety and economic impacts. There are a number of factors to consider when attempting to justify a complete system replacement versus a component by component replacement. This presentation will look at some of these systems which have been chosen for replacement and discuss the rationale used to drive this digital upgrade decision. Specific project related concerns due to the digital technology such as Software Qualification shall be addressed. Also specific to hybrid main control rooms is the Human Factors requirements when replacing analog controllers and meters with Touch Screen based HMI. One aspect of the Nuclear Power Plants which traditionally differs from other industry is the requirement for Full Scope Simulator for training purposes. This presention will identify the importance of the full scope simulator and the role it plays in digital system replacements. Other topics to be discussed in proposed presentation include: - Probablistic Risk Assessment; - Stakeholder Involvement; - New Technology Benefits; - New Technology 'Traps'; - Security; - Phased Acceptance Testing. The proposed presentation shall be in a PowerPoint format

  3. Analog IC reliability in nanometer CMOS

    Maricau, Elie


    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...

  4. Palytoxin and Analogs: Biological and Ecological Effects

    Vítor Ramos


    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.

  5. Four channel analog router for spectroscopy applications

    A four input analog multiplexer/router has been developed in order to acquire spectral data from four different detector systems on first-come-first-sort basis. The circuit is incorporated in a single width NIM module and is fully compatible with the HPD 4K MCA developed in the Health Physics Division. The analog router accepts output from upto 4 detectors after these are passed through individual preamplifiers and linear amplifiers. The router generates signal for the channel whose input crosses set LLD limits first and simultaneously disables other inputs. The selected input is then passed to the ADC for further processing. The processed signal generates a channel dependent two bit address along with normal digital outputs of the ADC. The channel dependent two bit address is directly used to store the event in one of the four 1k segment of the HPD 4K MCA. The multiplexer is re-enabled to accept next input on priority basis. One such unit has already been commissioned to acquire data from four solid state detectors used for spectrometry. The paper discusses hardware of the router, its linearity resolution cross-talk between the channels and other performance characteristics. (author). 3 figs

  6. Metastatic Insulinoma Managed with Radiolabeled Somatostatin Analog

    Ricardo Costa


    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.

  7. Operational Lessons Learned from NASA Analog Missions

    Arnold, Larissa S.


    vehicle and system capabilities are required to support the activities? How will the crew and the Earth-based mission control team interact? During the initial phases of manned planetary exploration, one challenge in particular is virtually the same as during the Apollo program: How can scientific return be maximized during a relatively short surface mission? Today, NASA is investigating solutions to these challenges by conducting analog missions. These Earth-based missions possess characteristics that are analogous to missions on the Moon or Mars. These missions are excellent for testing operational concepts, and the design, configuration, and functionality of spacesuits, robots, rovers, and habitats. Analog mission crews test specific techniques and procedures for surface field geology, biological sample collection, and planetary protection. The process of actually working an analog mission reveals a myriad of small details, which either contribute to or impede efficient operations, many of which would never have been thought about otherwise. It also helps to define the suite of tools, containers, and other small equipment that surface explorers will use. This paper focuses on how analog missions have addressed selected operational considerations for future planetary missions.

  8. Efecto de la quercetina sobre la nefrotoxicidad producida por cadmio

    A. I. Morales Martín


    Full Text Available El incremento en la producción anual de cadmio ha favorecido que la incidencia de la intoxicación crónica por este elemento haya aumentado en los últimos años. El estrés oxidativo es uno de los mecanismos implicados en la generación del efecto tóxico, manifestándose, entre otras patologías, por una disfunción y lesión renal. La quercetina, un flavonoide muy abundante en la dieta mediterránea, es un potente antioxidante y un buen quelante de metales. Nuestro objetivo fue estudiar si la administración de quercetina pudiera prevenir la aparición de los procesos nefrotóxicos asociados a la exposición crónica al cadmio. Los experimentos se realizaron con ratas Wistar (200g, incluidas en tres grupos experimentales: 1 ratas a las que se administró cadmio (1,2 mg/kg/día, s.c. cinco veces por semana, durante nueve semanas, 2 ratas a las cuales se les administró quercetina (50 mg/kg/día, i.p. cinco veces por semana, empezando en la cuarta semana y 3 ratas a las que se administró cadmio y quercetina. La lesión renal se evaluó midiendo proteinuria, microalbuminuria y glucosuria, así como la excreción de enzimas urinarias N-acetil-beta-D-glucosaminidasa, fosfatasa alcalina y gamma-glutamil-transpeptidasa. Las muestras de plasma se utilizaron para la determinación de creatinina y nitrógeno ureico plasmático, así como dialdehido malónico, como índice de peroxidación lipídica y antioxidantes totales en plasma. En riñón se midió la actividad enzimática de la superóxido dismutasa y de la glutation reductasa. Nuestros resultados mostraron que la administración de cadmio durante 9 semanas produjo un incremento en los valores de flujo urinario, proteinuria, microalbuminuria y glucosuria. El tratamiento con cadmio incluso incrementó la creatinina sérica y el nitrógeno uréico plasmático y elevó drásticamente la actividad de enzimas urinarias. Finalmente el aclaramiento de creatinina disminuyó como consecuencia de la

  9. Experiments on Evolving Software Models of Analog Circuits

    Lohn, Jason D.


    Analog circuits are of great importance in electronic system design since the world is fundamentally analog in nature. While the amount of digital design activity far outpaces that of analog design, most digital systems require analog modules for interfacing with the external world. It was recently estimated that approximately 60% of digital application- specific integrated circuit designs incorporated analog circuits. With challenging analog circuit design problems and few analog design engineers, there are economic reasons for automating the analog design process, especially time-to-market considerations. Techniques for analog circuit design automation began appearing about two decades ago. These methods incorporated heuristics [6], knowledge bases [1], simulated annealing [5], and other algorithms. Efforts using techniques from evolutionary computation began appearing over the last few years. These include the use of genetic algorithms to select electronic component values (for example, the resistance value of a resistor), to select circuit topologies, and to design amplifiers using a limited set of canned topologies [4]. A genetic programming-based analog circuit design system has been demonstrated in which the circuit sizes, component values, and the circuit topologies are determined automatically [3]. The genetic-algorithm systems typically represent circuit structures as vectors of parameters encoded in binary strings, while the genetic programming system manipulates tree data structures.

  10. Insulator contamination effects; Efectos de la contaminacion en aislamientos

    Gonzalez, Lucia [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)


    centros de produccion (contaminacion industrial); asimismo, en algunos casos para transportar energia, es necesario atravesar grandes extensiones de territorio en las que no existe vegetacion alguna (contaminacion desertica). Es por ello que el efecto de la contaminacion sobre las instalaciones electricas debe considerarse para lograr un suministro de energia confiable y economico.