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Sample records for 10-cm visual analog

  1. Learning Visualizations by Analogy: Promoting Visual Literacy through Visualization Morphing.

    PubMed

    Ruchikachorn, Puripant; Mueller, Klaus

    2015-09-01

    We propose the concept of teaching (and learning) unfamiliar visualizations by analogy, that is, demonstrating an unfamiliar visualization method by linking it to another more familiar one, where the in-betweens are designed to bridge the gap of these two visualizations and explain the difference in a gradual manner. As opposed to a textual description, our morphing explains an unfamiliar visualization through purely visual means. We demonstrate our idea by ways of four visualization pair examples: data table and parallel coordinates, scatterplot matrix and hyperbox, linear chart and spiral chart, and hierarchical pie chart and treemap. The analogy is commutative i.e. any member of the pair can be the unfamiliar visualization. A series of studies showed that this new paradigm can be an effective teaching tool. The participants could understand the unfamiliar visualization methods in all of the four pairs either fully or at least significantly better after they observed or interacted with the transitions from the familiar counterpart. The four examples suggest how helpful visualization pairings be identified and they will hopefully inspire other visualization morphings and associated transition strategies to be identified.

  2. Semantics by analogy for illustrative volume visualization.

    PubMed

    Gerl, Moritz; Rautek, Peter; Isenberg, Tobias; Gröller, Eduard

    2012-05-01

    We present an interactive graphical approach for the explicit specification of semantics for volume visualization. This explicit and graphical specification of semantics for volumetric features allows us to visually assign meaning to both input and output parameters of the visualization mapping. This is in contrast to the implicit way of specifying semantics using transfer functions. In particular, we demonstrate how to realize a dynamic specification of semantics which allows to flexibly explore a wide range of mappings. Our approach is based on three concepts. First, we use semantic shader augmentation to automatically add rule-based rendering functionality to static visualization mappings in a shader program, while preserving the visual abstraction that the initial shader encodes. With this technique we extend recent developments that define a mapping between data attributes and visual attributes with rules, which are evaluated using fuzzy logic. Second, we let users define the semantics by analogy through brushing on renderings of the data attributes of interest. Third, the rules are specified graphically in an interface that provides visual clues for potential modifications. Together, the presented methods offer a high degree of freedom in the specification and exploration of rule-based mappings and avoid the limitations of a linguistic rule formulation.

  3. Measurements of Output Factors For Small Photon Fields Up to 10 cm x 10 cm

    NASA Astrophysics Data System (ADS)

    Bacala, Angelina

    Field output factors (OF) for photon beams from a 6 MV medical accelerator were measured using five different detectors in a scanning water phantom. The measurements were taken for square field sizes of integral widths ranging from 1 cm to 10 cm for two reference source-to-surface distances (SSD) and depths in water. For the diode detectors, square field widths as small as 2.5 mm were also studied. The photon beams were collimated by using either the jaws or the multileaf collimators. Measured OFs are found to depend upon the field size, SSD, depth and also upon the type of beam collimation, size and type of detector used. For field sizes larger than 3 cm x 3 cm, the OF measurements agree to within 1% or less. The largest variation in OF occurs for jawsshaped field of size 1 cm x 1cm, where a difference of more than 18% is observed.

  4. Sex pheromone receptor proteins. Visualization using a radiolabeled photoaffinity analog

    SciTech Connect

    Vogt, R.G.; Prestwich, G.D.; Riddiford, L.M.

    1988-03-15

    A tritium-labeled photoaffinity analog of a moth pheromone was used to covalently modify pheromone-selective binding proteins in the antennal sensillum lymph and sensory dendritic membranes of the male silk moth, Antheraea polyphemus. This analog, (E,Z)-6,11-(/sup 3/H)hexadecadienyl diazoacetate, allowed visualization of a 15-kilodalton soluble protein and a 69-kilodalton membrane protein in fluorescence autoradiograms of electrophoretically separated antennal proteins. Covalent modification of these proteins was specifically reduced when incubation and UV irradiation were conducted in the presence of excess unlabeled pheromone, (E,Z)-6,11-hexadecadienyl acetate. These experiments constitute the first direct evidence for a membrane protein of a chemosensory neuron interacting in a specific fashion with a biologically relevant odorant.

  5. 10 cm x 10 cm Single Gas Electron Multiplier (GEM) X-ray Fluorescence Detector for Dilute Elements

    NASA Astrophysics Data System (ADS)

    Shaban, E. H.; Siddons, D. P.; Seifu, D.

    2014-03-01

    We have built and tested a 10 cm × 10 cm single Gas Electron Multiplier (GEM) X-ray detector to probe dilute amounts of Fe in a prepared sample. The detector uses Argon/Carbon Dioxide (75/25) gas mixture flowing at a slow rate through a leak proof Plexi-glass enclosure held together by O-rings and screws. The Fluorescence X-ray emitted by the element under test is directed through a Mylar window into the drift region of the detector where abundant gas is flowing. The ionized electrons are separated, drifted into the high electric field of the GEM, and multiplied by impact ionization. The amplified negatively charged electrons are collected and further amplified by a Keithley amplifier to probe the absorption edge of the element under test using X-ray absorption spectroscopy technique. The results show that the GEM detector provided good results with less noise as compared with a Silicon drift detector (SDD).

  6. Altimeter error sources at the 10-cm performance level

    NASA Technical Reports Server (NTRS)

    Martin, C. F.

    1977-01-01

    Error sources affecting the calibration and operational use of a 10 cm altimeter are examined to determine the magnitudes of current errors and the investigations necessary to reduce them to acceptable bounds. Errors considered include those affecting operational data pre-processing, and those affecting altitude bias determination, with error budgets developed for both. The most significant error sources affecting pre-processing are bias calibration, propagation corrections for the ionosphere, and measurement noise. No ionospheric models are currently validated at the required 10-25% accuracy level. The optimum smoothing to reduce the effects of measurement noise is investigated and found to be on the order of one second, based on the TASC model of geoid undulations. The 10 cm calibrations are found to be feasible only through the use of altimeter passes that are very high elevation for a tracking station which tracks very close to the time of altimeter track, such as a high elevation pass across the island of Bermuda. By far the largest error source, based on the current state-of-the-art, is the location of the island tracking station relative to mean sea level in the surrounding ocean areas.

  7. Visualizing Uncertainty for Probabilistic Weather Forecasting based on Reforecast Analogs

    NASA Astrophysics Data System (ADS)

    Pelorosso, Leandro; Diehl, Alexandra; Matković, Krešimir; Delrieux, Claudio; Ruiz, Juan; Gröeller, M. Eduard; Bruckner, Stefan

    2016-04-01

    Numerical weather forecasts are prone to uncertainty coming from inaccuracies in the initial and boundary conditions and lack of precision in numerical models. Ensemble of forecasts partially addresses these problems by considering several runs of the numerical model. Each forecast is generated with different initial and boundary conditions and different model configurations [GR05]. The ensembles can be expressed as probabilistic forecasts, which have proven to be very effective in the decision-making processes [DE06]. The ensemble of forecasts represents only some of the possible future atmospheric states, usually underestimating the degree of uncertainty in the predictions [KAL03, PH06]. Hamill and Whitaker [HW06] introduced the "Reforecast Analog Regression" (RAR) technique to overcome the limitations of ensemble forecasting. This technique produces probabilistic predictions based on the analysis of historical forecasts and observations. Visual analytics provides tools for processing, visualizing, and exploring data to get new insights and discover hidden information patterns in an interactive exchange between the user and the application [KMS08]. In this work, we introduce Albero, a visual analytics solution for probabilistic weather forecasting based on the RAR technique. Albero targets at least two different type of users: "forecasters", who are meteorologists working in operational weather forecasting and "researchers", who work in the construction of numerical prediction models. Albero is an efficient tool for analyzing precipitation forecasts, allowing forecasters to make and communicate quick decisions. Our solution facilitates the analysis of a set of probabilistic forecasts, associated statistical data, observations and uncertainty. A dashboard with small-multiples of probabilistic forecasts allows the forecasters to analyze at a glance the distribution of probabilities as a function of time, space, and magnitude. It provides the user with a more

  8. Evaluation of inpatient clinical documentation readiness for ICD-10-CM.

    PubMed

    DeAlmeida, Dilhari R; Watzlaf, Valerie J; Anania-Firouzan, Patti; Salguero, Otto; Rubinstein, Elaine; Abdelhak, Mervat; Parmanto, Bambang

    2014-01-01

    This research study examined the gaps in documentation that occur when coding in ICD-10-CM. More than 4,000 diagnoses from all chapters were coded from 656 electronic documents obtained from a large integrated healthcare facility at the time the study was conducted (2012). After the documents were coded, areas for documentation improvement were identified for chapters that resulted in deficiencies in documentation, and a quick reference guide was developed. The overall absent documentation percentage was 15.4 percent. The 10 chapters with the highest percentage of absent documentation were chapter 7 (Diseases of Eye and Adnexa), with 67.65 percent (p < .001); chapter 8 (Diseases of Ear and Mastoid Process), with 63.64 percent (p < .001); chapter 13 (Diseases of the Musculoskeletal System and Connective Tissue), with 46.05 percent (p < .001); chapter 14 (Diseases of the Genitourinary System), with 40.29 percent (p < .001); chapter 10 (Diseases of Respiratory System), with 35.52 percent (p < .001); chapter 1 (Infectious and Parasitic Diseases), with 32.88 percent (p < .001); chapter 12 (Diseases of the Skin and Subcutaneous Tissue), with 32.35 percent (p < .001); chapter 2 (Neoplasms), with 25.45 percent (p < .001); chapter 4 (Endocrine, Nutritional and Metabolic Diseases), with 14.58 percent (p < .001); and chapter 17 (Congenital Malformations, Deformations, and Chromosomal Abnormalities), with 12.50 percent. We addressed the deficient areas in the quick reference guide developed for clinicians and technology vendors. Having complete and accurate documentation would benefit both the clinician and the patient in providing the highest quality of care.

  9. The Effects of Visual Display on Analogies Using Computer-Based Learning.

    ERIC Educational Resources Information Center

    Lai, Shu-Ling

    1998-01-01

    Describes a study that investigated the effects of visual display within a college computer-based learning program that taught computer programming language through analogies. Three types of visual displays (text, static graphics, and animation) are compared, and assessment measures that included posttests and attitude questionnaires are…

  10. Visualizing Cosmological Concepts Using the Analog of a Hot Liquid

    ERIC Educational Resources Information Center

    Yusofi, E.; Mohsenzadeh, M.

    2010-01-01

    We have used the expansion process of hot milk, which has similarities with the cosmic expansion, to facilitate easier and better visualization and teaching of cosmological concepts. Observations of milk are used to illustrate phenomena related to the Planck era, the standard hot big bang model, cosmic inflation, problems with the formation of…

  11. 77 FR 32975 - AHRQ Workgroups on ICD-10-CM/PCS Conversion of Quality Indicators (QIs)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-04

    ... HUMAN SERVICES Agency for Healthcare Research and Quality AHRQ Workgroups on ICD-10-CM/PCS Conversion of... nominations for members of approximately 10 multidisciplinary workgroups, to be convened by AHRQ's contractor, on ICD-10-CM/PCS conversion of the AHRQ Quality Indicators (QIs). DATES: Please submit nominations...

  12. Readers' Use of Analogic and Visual Aids for Understanding and Remembering Complex Prose.

    ERIC Educational Resources Information Center

    Hayes, David A.

    A study researched the differential uses readers make of analogic and visual prompts for understanding and remembering complex prose. Fifty-two eleventh grade students with average and above average reading ability enrolled in a comprehensive high school in central Georgia participated in the study. They were ranked according to their ability to…

  13. Relationship of stimulus and examinee variables to performance on analogous visual and tactile block construction tasks.

    PubMed

    Miller, Joseph C; Skillman, Gemma D

    2008-01-01

    Nonverbal/spatial tests are unavailable for persons with visual impairments, despite decades of documented need and developmental effort. Because past tactile analogs of block design (BD) tests have not been widely accepted, known BD test parameters were compared across visual and tactile designs to assess the applicability of the test across modalities. Contrary to expectations, edge-cueing of designs with no perceptual cohesiveness (PC) improved tactile and visual performance. The expected PC by cueing and field independence (FI) by PC interactions were found for visual, but not tactile, BD. Uncued tactile designs elicited more errors, tending to occur closer to the center of the designs. These data suggest that visual and tactile BD performance cannot be interpreted similarly. Differences may be due to to modality-specific demand for various encoding and recoding abilities. The standing model is expanded to account for cross-modality differences in BD performance by including both rotation and block segregation.

  14. Displays. [three dimensional analog visual system for aiding pilot space perception

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An experimental investigation made to determine the depth cue of a head movement perspective and image intensity as a function of depth is summarized. The experiment was based on the use of a hybrid computer generated contact analog visual display in which various perceptual depth cues are included on a two dimensional CRT screen. The system's purpose was to impart information, in an integrated and visually compelling fashion, about the vehicle's position and orientation in space. Results show head movement gives a 40% improvement in depth discrimination when the display is between 40 and 100 cm from the subject; intensity variation resulted in as much improvement as head movement.

  15. Measuring preoperative anxiety in patients with breast cancer using the visual analog scale.

    PubMed

    Aviado-Langer, Jennifer

    2014-10-01

    Preoperative anxiety is a prevalent concern with deleterious effects in patient recovery and is not routinely assessed in the preoperative screening process. When it is assessed, it may prompt an increase in the use of anesthetic agents, heightened postoperative pain, and prolonged hospitalization. Preoperative women with breast cancer face anxiety as it relates to anesthesia, surgery, and recovery. The preoperative anxiety visual analog scale may identify and quantify anxiety in this population, provide advocacy and support, and improve the preoperative screening process.

  16. Handling Age Specification in the SNOMED CT to ICD-10-CM Cross-map

    PubMed Central

    Xu, Junchuan; Fung, Kin Wah

    2012-01-01

    A SNOMED CT-encoded problem list will be required to satisfy the Certification Criteria for Stage 2 “Meaningful Use” of the EHR incentive program. ICD-10-CM will be replacing ICD-9-CM as the reimbursement code set in the near future. Having a cross-map from SNOMED CT to ICD-10-CM will promote the use of SNOMED CT as the primary problem list terminology, while easing the transition to ICD-10-CM. This rule-based map will support semi-automatic generation of ICD-10-CM codes from SNOMED CT-encoded data. Among the different types of rules, the age rule is used to handle age-specific code assignment in ICD-10-CM. To supplement the manual process of creation of age rules, a special QA process was implemented to flag maps that were potentially missing age rules. The QA flagged 342 concepts for review (out of 7,277), of which 172 concepts (50.3%) were true positives. Without the special QA, many of the age rules would have been missed. PMID:23304377

  17. Results from the Veterans Health Administration ICD-10-CM/PCS Coding Pilot Study.

    PubMed

    Weems, Shelley; Heller, Pamela; Fenton, Susan H

    2015-01-01

    The Veterans Health Administration (VHA) of the US Department of Veterans Affairs has been preparing for the October 1, 2015, conversion to the International Classification of Diseases, Tenth Revision, Clinical Modification and Procedural Coding System (ICD-10-CM/PCS) for more than four years. The VHA's Office of Informatics and Analytics ICD-10 Program Management Office established an ICD-10 Learning Lab to explore expected operational challenges. This study was conducted to determine the effects of the classification system conversion on coding productivity. ICD codes are integral to VHA business processes and are used for purposes such as clinical studies, performance measurement, workload capture, cost determination, Veterans Equitable Resource Allocation (VERA) determination, morbidity and mortality classification, indexing of hospital records by disease and operations, data storage and retrieval, research purposes, and reimbursement. The data collection for this study occurred in multiple VHA sites across several months using standardized methods. It is commonly accepted that coding productivity will decrease with the implementation of ICD-10-CM/PCS. The findings of this study suggest that the decrease will be more significant for inpatient coding productivity (64.5 percent productivity decrease) than for ambulatory care coding productivity (6.7 percent productivity decrease). This study reveals the following important points regarding ICD-10-CM/PCS coding productivity: 1. Ambulatory care ICD-10-CM coding productivity is not expected to decrease as significantly as inpatient ICD-10-CM/PCS coding productivity. 2. Coder training and type of record (inpatient versus outpatient) affect coding productivity. 3. Inpatient coding productivity is decreased when a procedure requiring ICD-10-PCS coding is present. It is highly recommended that organizations perform their own analyses to determine the effects of ICD-10-CM/PCS implementation on coding productivity.

  18. Conducting Retrospective Ontological Clinical Trials in ICD-9-CM in the Age of ICD-10-CM

    PubMed Central

    Venepalli, Neeta K; Shergill, Ardaman; Dorestani, Parvaneh; Boyd, Andrew D

    2014-01-01

    OBJECTIVE To quantify the impact of International Classification of Disease 10th Revision Clinical Modification (ICD-10-CM) transition in cancer clinical trials by comparing coding accuracy and data discontinuity in backward ICD-10-CM to ICD-9-CM mapping via two tools, and to develop a standard ICD-9-CM and ICD-10-CM bridging methodology for retrospective analyses. BACKGROUND While the transition to ICD-10-CM has been delayed until October 2015, its impact on cancer-related studies utilizing ICD-9-CM diagnoses has been inadequately explored. MATERIALS AND METHODS Three high impact journals with broad national and international readerships were reviewed for cancer-related studies utilizing ICD-9-CM diagnoses codes in study design, methods, or results. Forward ICD-9-CM to ICD-10-CM mapping was performing using a translational methodology with the Motif web portal ICD-9-CM conversion tool. Backward mapping from ICD-10-CM to ICD-9-CM was performed using both Centers for Medicare and Medicaid Services (CMS) general equivalence mappings (GEMs) files and the Motif web portal tool. Generated ICD-9-CM codes were compared with the original ICD-9-CM codes to assess data accuracy and discontinuity. RESULTS While both methods yielded additional ICD-9-CM codes, the CMS GEMs method provided incomplete coverage with 16 of the original ICD-9-CM codes missing, whereas the Motif web portal method provided complete coverage. Of these 16 codes, 12 ICD-9-CM codes were present in 2010 Illinois Medicaid data, and accounted for 0.52% of patient encounters and 0.35% of total Medicaid reimbursements. Extraneous ICD-9-CM codes from both methods (Centers for Medicare and Medicaid Services general equivalent mapping [CMS GEMs, n = 161; Motif web portal, n = 246]) in excess of original ICD-9-CM codes accounted for 2.1% and 2.3% of total patient encounters and 3.4% and 4.1% of total Medicaid reimbursements from the 2010 Illinois Medicare database. DISCUSSION Longitudinal data analyses post-ICD-10

  19. Synthesis of analogs of the radiation mitigator JP4-039 and visualization of BODIPY derivatives in mitochondria

    PubMed Central

    Frantz, Marie-Céline; Skoda, Erin M.; Sacher, Joshua R.; Epperly, Michael W.; Goff, Julie P.; Greenberger, Joel S.

    2013-01-01

    JP4-039 is a lead structure in a series of nitroxide conjugates that are capable of accumulating in mitochondria and scavenging reactive oxygen species (ROS). To explore structure-activity relationships (SAR), new analogs with variable nitroxide moieties were prepared. Furthermore, fluorophore-tagged analogs were synthesized and provided the opportunity for visualization in mitochondria. All analogs were tested for radioprotective and radiomitigative effects in 32Dcl3 cells. PMID:23715589

  20. Proposed ICD-10-CM Surveillance Case Definitions for Injury Hospitalizations and Emergency Department Visits.

    PubMed

    Hedegaard, Holly B; Johnson, Renee L; Ballesteros, Michael F

    2017-01-01

    This report describes a collaboration between the National Center for Health Statistics and the National Center for Injury Prevention and Control to develop proposed surveillance case definitions for injury hospitalizations and emergency department (ED) visits for use with administrative data sets coded using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM). The proposed ICD-10-CM surveillance case definitions were developed by applying General Equivalence Mappings to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) definitions. As with the ICD-9-CM definitions, there are slight differences between the proposed ICD-10-CM surveillance case definition for injury hospitalizations and the one for ED visits. The inclusion criteria for an injury hospitalization requires a case to have a principal diagnosis of one of the included nature-of-injury (injury diagnosis) codes. The inclusion criteria for an injury ED visit requires the case to have either a principal diagnosis of one of the included nature-of-injury codes or the presence of selected external-cause codes. The ICD-10-CM nature-of-injury and external-cause codes included in the proposed definitions are presented and caveats for use of the proposed definitions are described.

  1. Lessons Learned from an ICD-10-CM Clinical Documentation Pilot Study

    PubMed Central

    Moczygemba, Jackie; Fenton, Susan H

    2012-01-01

    On October 1, 2013, the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) will be mandated for use in the United States in place of the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). This new classification system will used throughout the nation's healthcare system for recording diagnoses or the reasons for treatment or care. A pilot study was conducted to determine whether current levels of inpatient clinical documentation provide the detail necessary to fully utilize the ICD-10-CM classification system for heart disease, pneumonia, and diabetes cases. The design of this pilot study was cross-sectional. Four hundred ninety-one de-identified records from two sources were coded using ICD-10-CM guidelines and codebooks. The findings of this study indicate that healthcare organizations need to assess clinical documentation and identify gaps. In addition, coder proficiency should be assessed prior to ICD-10-CM implementation to determine the need for further education and training in the biomedical sciences, along with training in the new classification system. PMID:22548021

  2. Physicians’ Outlook on ICD-10-CM/PCS and Its Effect on Their Practice

    PubMed Central

    Watzlaf, Valerie; Alkarwi, Zahraa; Meyers, Sandy; Sheridan, Patty

    2015-01-01

    Background The United States is one of the last countries to change from ICD-9-CM to ICD-10-CM/PCS. The compliance date for implementation of ICD-10-CM/PCS is expected to fall on October 1, 2015. Objectives Evaluate physicians’ perceptions on the change from ICD-9-CM to ICD-10-CM/PCS and its effect on their practice, determine how HIM professionals can assist in this transition, and assess what resources are needed to aid in the transition. Results Twenty physicians were asked to participate in one of three focus groups. Twelve physicians (60 percent) agreed to participate. Top concerns included electronic health record software readiness, increase in documentation specificity and time, ability of healthcare professionals to learn a new language, and inadequacy of current training methods and content. Conclusion Physicians expressed that advantages of ICD-10-CM/PCS were effective data analytics and complexity of patient cases with more specific codes. Health information management professionals were touted as needed during the transition to create simple, clear specialty guides and crosswalks as well as education and training tools specific for physicians. PMID:26807074

  3. Auxin transport sites are visualized in planta using fluorescent auxin analogs.

    PubMed

    Hayashi, Ken-ichiro; Nakamura, Shouichi; Fukunaga, Shiho; Nishimura, Takeshi; Jenness, Mark K; Murphy, Angus S; Motose, Hiroyasu; Nozaki, Hiroshi; Furutani, Masahiko; Aoyama, Takashi

    2014-08-05

    The plant hormone auxin is a key morphogenetic signal that controls many aspects of plant growth and development. Cellular auxin levels are coordinately regulated by multiple processes, including auxin biosynthesis and the polar transport and metabolic pathways. The auxin concentration gradient determines plant organ positioning and growth responses to environmental cues. Auxin transport systems play crucial roles in the spatiotemporal regulation of the auxin gradient. This auxin gradient has been analyzed using SCF-type E3 ubiquitin-ligase complex-based auxin biosensors in synthetic auxin-responsive reporter lines. However, the contributions of auxin biosynthesis and metabolism to the auxin gradient have been largely elusive. Additionally, the available information on subcellular auxin localization is still limited. Here we designed fluorescently labeled auxin analogs that remain active for auxin transport but are inactive for auxin signaling and metabolism. Fluorescent auxin analogs enable the selective visualization of the distribution of auxin by the auxin transport system. Together with auxin biosynthesis inhibitors and an auxin biosensor, these analogs indicated a substantial contribution of local auxin biosynthesis to the formation of auxin maxima at the root apex. Moreover, fluorescent auxin analogs mainly localized to the endoplasmic reticulum in cultured cells and roots, implying the presence of a subcellular auxin gradient in the cells. Our work not only provides a useful tool for the plant chemical biology field but also demonstrates a new strategy for imaging the distribution of small-molecule hormones.

  4. ICD-10-CM/PCS: Transferring Knowledge from ICD-9-CM

    PubMed Central

    Sand, Jaime N.; Elison-Bowers, Patt

    2013-01-01

    The transition to ICD-10-CM/PCS has expanded educational opportunities for educators and trainers who are taking on the responsibility of training coders on the new system. Coding education currently faces multiple challenges in the areas of how to train the new workforce, what might be the most efficient method of providing that training, how much retraining of the current workforce with ICD-9-CM training will be required, and how to meet the national implementation deadline of 2014 in the most efficacious manner. This research sought to identify if there was a difference between a group of participants with no knowledge of ICD-9-CM and those with some knowledge of ICD-9-CM in scores on an ICD-10-CM/PCS quiz. Results indicate a difference, supporting the idea of knowledge transfer between the systems and providing additional insight into coding education. PMID:23861677

  5. Digital to Analog Conversion and Visual Evaluation of Thematic Mapper Data

    USGS Publications Warehouse

    McCord, James R.; Binnie, Douglas R.; Seevers, Paul M.

    1985-01-01

    As a part of the National Aeronautics and Space Administration Landsat D Image Data Quality Analysis Program, the Earth Resources Observation Systems Data Center (EDC) developed procedures to optimize the visual information content of Thematic Mapper data and evaluate the resulting photographic products by visual interpretation. A digital-to-analog transfer function was developed which would properly place the digital values on the most useable portion of a film response curve. Individual black-and-white transparencies generated using the resulting look-up tables were utilized in the production of color-composite images with varying band combinations. Four experienced photointerpreters ranked 2-cm-diameter (0. 75 inch) chips of selected image features of each band combination for ease of interpretability. A nonparametric rank-order test determined the significance of interpreter preference for the band combinations.

  6. Digital to analog conversion and visual evaluation of Thematic Mapper data

    USGS Publications Warehouse

    McCord, James R.; Binnie, Douglas R.; Seevers, Paul M.

    1985-01-01

    As a part of the National Aeronautics and Space Administration Landsat D Image Data Quality Analysis Program, the Earth Resources Observation Systems Data Center (EDC) developed procedures to optimize the visual information content of Thematic Mapper data and evaluate the resulting photographic products by visual interpretation. A digital-to-analog transfer function was developed which would properly place the digital values on the most useable portion of a film response curve. Individual black-and-white transparencies generated using the resulting look-up tables were utilized in the production of color-composite images with varying band combinations. Four experienced photointerpreters ranked 2-cm-diameter (0. 75 inch) chips of selected image features of each band combination for ease of interpretability. A nonparametric rank-order test determined the significance of interpreter preference for the band combinations.

  7. 78 FR 70558 - Review of Proposed Changes with ICD-10-CM/PCS; Conversion of Quality IndicatorsTM

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Quality Review of Proposed Changes with ICD-10-CM/PCS; Conversion of Quality Indicators TM (QIs) AGENCY..., Clinical Modification/Procedure Coding System'' (ICD-10- CM and ICD-10-PCS) codes. These changes would be applicable to hospital discharges occurring on or after October 1, 2014. The proposed ICD-10- CM/PCS...

  8. Evaluation of Argonne 9-cm and 10-cm Annular Centrifugal Contactors for SHINE Solution Processing

    SciTech Connect

    Wardle, Kent E.; Pereira, Candido; Vandegrift, George

    2015-02-01

    Work is in progress to evaluate the SHINE Medical Technologies process for producing Mo-99 for medical use from the fission of dissolved low-enriched uranium (LEU). This report addresses the use of Argonne annular centrifugal contactors for periodic treatment of the process solution. In a letter report from FY 2013, Pereira and Vandegrift compared the throughput and physical footprint for the two contactor options available from CINC Industries: the V-02 and V-05, which have rotor diameters of 5 cm and 12.7 cm, respectively. They suggested that an intermediately sized “Goldilocks” contactor might provide a better balance between throughput and footprint to meet the processing needs for the uranium extraction (UREX) processing of the SHINE solution to remove undesired fission products. Included with the submission of this letter report are the assembly drawings for two Argonne-design contactors that are in this intermediate range—9-cm and 10-cm rotors, respectively. The 9-cm contactor (drawing number CE-D6973A, stamped February 15, 1978) was designed as a single-stage unit and built and tested in the late 1970s along with other size units, both smaller and larger. In subsequent years, a significant effort to developed annular centrifugal contactors was undertaken to support work at Hanford implementing the transuranic extraction (TRUEX) process. These contactors had a 10-cm rotor diameter and were fully designed as multistage units with four stages per assembly (drawing number CMT-E1104, stamped March 14, 1990). From a technology readiness perspective, these 10-cm units are much farther ahead in the design progression and, therefore, would require significantly less re-working to make them ready for UREX deployment. Additionally, the overall maximum throughput of ~12 L/min is similar to that of the 9-cm unit (10 L/min), and the former could be efficiently operated over much of the same range of throughput. As a result, only the 10-cm units are considered here

  9. The next big challenge for EPs: The transition to ICD-10-CM coding system.

    PubMed

    2015-08-01

    The long-delayed transition to the International Classification of Diseases, Clinical Modification administrative codes (lCD-10-CM) is set to take place in October, presenting a host of challenges for EPs. A new analysis suggests roughly a quarter of the clinical encounters that take place in the ED will involve complexity in the transition to the new system. Further, experts anticipate workflow challenges as well as new considerations when making planning decisions and reporting to public health departments. The number of codes available to providers will jump from 14,000 to 80,000 with the transition to the new coding system. Investigators found that that 23% of the visits, or 27% of the codes, emergency medicine physicians use are complex. The new coding system requires much more specificity, but there are also instances in which definitions have been altered or blended together, essentially changing the concepts described. While all EPs will face some challenges with the new coding system, analysts are particularly concerned about smaller EDs and physician groups because these practices typically don't have the ICD-10-CM implementation teams that larger systems have.

  10. Visualizing the Analogy between Competitive Adsorption and Colloid Stability to Restore Lung Surfactant Function

    PubMed Central

    Shieh, Ian C.; Waring, Alan J.; Zasadzinski, Joseph A.

    2012-01-01

    We investigated a model of acute respiratory distress syndrome in which the serum protein albumin adsorbs to an air-liquid interface and prevents the thermodynamically preferable adsorption of the clinical lung surfactant Survanta by inducing steric and electrostatic energy barriers analogous to those that prevent colloidal aggregation. Chitosan and polyethylene glycol (PEG), two polymers that traditionally have been used to aggregate colloids, both allow Survanta to quantitatively displace albumin from the interface, but through two distinct mechanisms. Direct visualization with confocal microscopy shows that the polycation chitosan coadsorbs to interfacial layers of both Survanta and albumin, and also colocalizes with the anionic domains of Survanta at the air-liquid interface, consistent with it eliminating the electrostatic repulsion by neutralizing the surface charges on albumin and Survanta. In contrast, the PEG distribution does not change during the displacement of albumin by Survanta, consistent with PEG inducing a depletion attraction sufficient to overcome the repulsive energy barrier toward adsorption. PMID:22385848

  11. A new visual analog scale to measure distinctive well-being effects of LED photobiomodulation

    NASA Astrophysics Data System (ADS)

    Michel, François; Barolet, Daniel

    2016-03-01

    LED photobiomodulation is known mostly for its restorative effects on skin and joints. While providing LED photobiomodulation aesthetic treatments of the face, not only the skin condition was improved, but a subjective well-being effect was observed, obvious both in photographs of the treated areas and in patient behaviour. This has been supported by studies showing the beneficial effects of transcranial lasers and LEDs on neurological and psychological conditions, providing great insight. LED therapy can now be used as a standalone procedure to regulate neuronal function. To measure such neurological outcomes in humans, we developed a visual analog scale questionnaire with the purpose of having a convenient tool for the assessment of quality of life following facial LED photobiomodulation.We also gauged patients' emotional state regarding overall aesthetic improvement.

  12. Organic blend semiconductors and transistors with hole mobility exceeding 10 cm2/Vs (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Paterson, Alexandra F.; Anthopoulos, Thomas D.

    2015-10-01

    Plastic electronics that can be manufactured using solution-based methods are the subject of great research interest due to their potential for low-cost, large-area electronic applications. The interest in this field has led to considerable research and subsequent advances in device performance. To this end solution-processed organic thin-film transistors (OTFTs) have shown impressive improvements in recent years through the increasing values of charge carrier mobility. Here we report the development of next generation organic blend materials for OTFTs with hole mobilities of 10 cm2/Vs. These high performance devices have been achieved using a novel semiconducting blend system comprising of an amorphous-like conjugated polymer and a high mobility small molecule. The combination of a highly crystalline small molecule with the polymer binder aids the formation of uniform films as well as enables an element of control over the nucleation and growth of the small molecule. The polymer binders investigated belongs to the family of indacenodithiophene-based copolymers which are renowned for their high carrier mobilities regardless of their apparent structural disorder. The addition of the polymer with carefully chosen small molecules is found to further increase the hole mobility of the resulting blend OTFT to over 10 cm2/Vs. These organic devices provide an interesting insight into this rather complex blend system, highlighting the correlation between the morphology developed following solution processing and device performance, as well as exploring the role of each of the two components in the blend in terms of their contribution to charge transport.

  13. Dizziness Handicap Inventory and Visual Vertigo Analog Scale in Vestibular Dysfunction

    PubMed Central

    Grigol, Thaís Alvares de Abreu e Silva; Silva, Adriana Marques; Ferreira, Maristela Mian; Manso, Andrea; Ganança, Maurício Malavasi; Caovilla, Heloisa Helena

    2015-01-01

    Introduction  Dizziness is one of the most common symptoms among the population, producing numerous consequences for individual's quality of life. There are some questionnaires that can trace the patient's profile and quality of life impairment from dizziness, including the Dizziness Handicap Inventory (DHI) and the Visual Vertigo Analogue Scale (VVAS). Objective  This study aims to correlate the results of the DHI and VVAS in patients with vestibular dysfunction. Methods  This is a retrospective study of medical records of patients treated in a medical school between 2006 and 2012. Results of the DHI and EVA were collected and subjected to statistical analysis using Pearson's correlation test with p < 0.001. The significance level adopted for the statistical tests was p ≤ 0.05. Results  A total of 91 records were included in this study, 72 (79.1%) from female and 19 (20.9%) from male patients, aged 23 to 86 years, with a mean age of 52.5 years. The mean score on the DHI total was 43.9 and 5.2 points for the EVA. The result of Pearson's correlation test was 0.54. Conclusion  Self-perceived dizziness measured with the Dizziness Handicap Inventory has a regular and positive correlation with the Visual Vertigo Analog Scale in patients with vestibular dysfunction. The clinical trial is registered under number UTN U1111–1170–5065. PMID:27413406

  14. Estimation of CO2 diffusion coefficient at 0-10 cm depth in undisturbed and tilled soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Diffusion coefficients (D) of CO2 at 0 – 10 cm layers in undisturbed and tilled soil conditions were estimated using Penman, Millington-Quirk, Ridgwell et al. (1999), Troeh et al., and Moldrup et al. models. Soil bulk density and volumetric soil water content ('v) at 0 – 10 cm were measured on April...

  15. 77 FR 40620 - AHRQ Workgroups on ICD-10-CM/PCS Conversion of Quality Indicators (QIs) - Extension Date for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-10

    ... HUMAN SERVICES Agency for Healthcare Research and Quality AHRQ Workgroups on ICD-10-CM/PCS Conversion of... Quality (AHRQ) is seeking nominations for members of approximately 10 multidisciplinary workgroups, to be convened by AHRQ's contractor, on ICD-10-CM/PCS conversion of the AHRQ Quality Indicators (QIs)....

  16. Assessing the planning and implementation strategies for the ICD-10-CM/PCS coding transition in Alabama hospitals.

    PubMed

    Houser, Shannon H; Morgan, Darius; Clements, Kay; Hart-Hester, Susan

    2013-01-01

    Health information management (HIM) professionals play a significant role in transitioning from ICD-9-CM to ICD-10-CM/PCS. ICD-10-CM/PCS coding will impact many operational aspects of healthcare facilities, such as physicians' documentation in health records, coders' process for review of clinical information, the billing process, and the payers' reimbursement to the healthcare facilities. This article examines the level of readiness and planning for ICD-10-CM/PCS implementation among hospitals in Alabama, identifies training methods/approaches to be used by the hospitals, and discusses the challenges to the ICD-10-CM/PCS coding transition. A 16-question survey was distributed to 116 Alabama hospital HIM directors in December 2011 with follow-up through February 2012. Fifty-three percent of respondent hospitals began the planning process in 2011, and most facilities were halfway or less than halfway to completion of specific implementation tasks. Hospital coders will be or are being trained using in-house training, through seminars/webinars, or by consultants. The impact of ICD-10-CM/PCS implementation can be minimized by training coders in advance, hiring new coders, and adjusting coders' productivity measures. Three major challenges to the transition were identified: the need to interact with physicians and other providers more often to obtain information needed to code in ICD-10-CM/PCS systems, education and training of coders and other ICD-10-CM/PCS users, and dependence on vendors for major technology upgrades for ICD-10-CM/PCS systems. Survey results provide beneficial information for HIM professionals and other users of coded data to assist in establishing sound practice standards for ICD-10-CM/PCS coding implementation. Adequate planning and preparation will be essential to the successful implementation of ICD-10-CM/PCS.

  17. Navigating Regulatory Change: Preliminary Lessons Learned During the Healthcare Provider Transition to ICD-10-CM/PCS

    PubMed Central

    Jackson, Veronica E; Muckerman, Alexander

    2012-01-01

    This article presents the findings of a collaborative effort between the Georgetown University Student Consulting Team and Booz Allen Hamilton to interview healthcare providers undergoing the transition to the International Classification of Diseases, Tenth Revision, Clinical Modification/Procedure Coding System (ICD-10-CM/PCS). The goals of this study were to extract a common set of trends, challenges, and lessons learned surrounding the implementation of the ICD-10-CM/PCS code set and to produce actionable information that might serve as a resource for organizations navigating the transition to ICD-10-CM/PCS. The selected survey sample focused on a subset of large hospitals, integrated health systems, and other national industry leaders who are likely to have initiated the implementation process far in advance of the October 2013 deadline. Guided by a uniform survey tool, the team conducted a series of one-on-one provider interviews with department heads, senior staff members, and project managers leading ICD-10-CM/PCS conversion efforts from six diverse health systems. As expected, the integrated health systems surveyed seem to be on or ahead of schedule for the ICD-10-CM/PCS coding transition. However, results show that as of April 2010 most providers were still in the planning stages of implementation and were working to raise awareness within their organizations. Although individual levels of preparation varied widely among respondents, the study identified several trends, challenges, and lessons learned that will enable healthcare providers to assess their own status with respect to the industry and will provide useful insight into best practices for the ICD-10-CM/PCS transition. PMID:22548022

  18. The Complexity and Challenges of the ICD-9-CM to ICD-10-CM Transition in Emergency Departments

    PubMed Central

    Krive, Jacob; Patel, Mahatkumar; Gehm, Lisa; Mackey, Mark; Kulstad, Erik; Li, Jianrong ‘John’; Lussier, Yves A.; Boyd, Andrew D.

    2015-01-01

    Beginning October 2015, the Center for Medicare and Medicaid Services (CMS) will require medical providers to utilize the vastly expanded ICD-10-CM system. Despite wide availability of information and mapping tools for the next generation of the ICD classification system, some of the challenges associated with transition from ICD-9-CM to ICD-10-CM are not well understood. To quantify the challenges faced by emergency physicians, we analyzed a subset of a 2010 Illinois Medicaid database of emergency department ICD-9-CM codes, seeking to determine the accuracy of existing mapping tools in order to better prepare emergency physicians for the change to the expanded ICD-10-CM system. We found that 27% of 1,830 codes represented convoluted multidirectional mappings. We then analyzed the convoluted transitions and found 8% of total visit encounters (23% of the convoluted transitions) were clinically incorrect. The ambiguity and inaccuracy of these mappings may impact the work flow associated with the translation process and affect the potential mapping between ICD codes and CPT (Current Procedural Codes) codes, which determine physician reimbursement. PMID:25863652

  19. Assessment of Dyspnea Early in Acute Heart Failure: Patient Characteristics and Response Differences Between Likert and Visual Analog Scales

    PubMed Central

    Pang, Peter S.; Collins, Sean P.; Sauser, Kori; Andrei, Adin-Cristian; Storrow, Alan B.; Hollander, Judd E.; Tavares, Miguel; Spinar, Jindrich; Macarie, Cezar; Raev, Dimitar; Nowak, Richard; Gheorghiade, Mihai; Mebazaa, Alexandre

    2014-01-01

    Background Dyspnea is the most common symptom in acute heart failure (AHF), yet how to best measure it has not been well defined. Prior studies demonstrate differences in dyspnea improvement across various measurement scales, yet these studies typically enroll patients well after the ED phase of management. Objectives The aim of this study was to determine predictors of early dyspnea improvement for three different, commonly used dyspnea scales (i.e. five point absolute Likert scale, 10 cm visual analogue scale [VAS], or seven point relative Likert scale). Methods This was a post-hoc analysis of URGENT Dyspnea, an observational study of 776 patients in 17 countries enrolled within one hour of first physician encounter. Inclusion criteria were broad to reflect real-world clinical practice. Prior literature informed the a priori definition of clinically significant dyspnea improvement. Resampling-based multivariable models were created to determine patient characteristics significantly associated with dyspnea improvement. Results Of the 524 AHF patients, approximately 40% of patients did not report substantial dyspnea improvement within the first 6 hours. Baseline characteristics were similar between those who did or did not improve, though there were differences in history of heart failure, coronary artery disease, and initial systolic blood pressure. For those who did improve, patient characteristics differed across all three scales, with the exception of baseline dyspnea severity for the VAS and five point Likert scale (c-index ranged from 0.708 to 0.831 for each scale). Conclusions Predictors of early dyspnea improvement differ from scale to scale, with the exception of baseline dyspnea. Attempts to use one scale to capture the entirety of the dyspnea symptom may be insufficient. PMID:25039550

  20. Projected Impact of the ICD-10-CM/PCS Conversion on Longitudinal Data and the Joint Commission Core Measures

    PubMed Central

    Fenton, Susan H.; Benigni, Mary Sue

    2014-01-01

    The transition from ICD-9-CM to ICD-10-CM/PCS is expected to result in longitudinal data discontinuities, as occurred with cause-of-death in 1999. The General Equivalence Maps (GEMs), while useful for suggesting potential maps do not provide guidance regarding the frequency of any matches. Longitudinal data comparisons can only be reliable if they use comparability ratios or factors which have been calculated using records coded in both classification systems. This study utilized 3,969 de-identified dually coded records to examine raw comparability ratios, as well as the comparability ratios between the Joint Commission Core Measures. The raw comparability factor results range from 16.216 for Nicotine dependence, unspecified, uncomplicated to 118.009 for Chronic obstructive pulmonary disease, unspecified. The Joint Commission Core Measure comparability factor results range from 27.15 for Acute Respiratory Failure to 130.16 for Acute Myocardial Infarction. These results indicate significant differences in comparability between ICD-9-CM and ICD-10-CM code assignment, including when the codes are used for external reporting such as the Joint Commission Core Measures. To prevent errors in decision-making and reporting, all stakeholders relying on longitudinal data for measure reporting and other purposes should investigate the impact of the conversion on their data. PMID:25214824

  1. A case study demonstration of the soil temperature extrema recovery rates after precipitation cooling at 10-cm soil depth

    NASA Technical Reports Server (NTRS)

    Welker, Jean Edward

    1991-01-01

    Since the invention of maximum and minimum thermometers in the 18th century, diurnal temperature extrema have been taken for air worldwide. At some stations, these extrema temperatures were collected at various soil depths also, and the behavior of these temperatures at a 10-cm depth at the Tifton Experimental Station in Georgia is presented. After a precipitation cooling event, the diurnal temperature maxima drop to a minimum value and then start a recovery to higher values (similar to thermal inertia). This recovery represents a measure of response to heating as a function of soil moisture and soil property. Eight different curves were fitted to a wide variety of data sets for different stations and years, and both power and exponential curves were fitted to a wide variety of data sets for different stations and years. Both power and exponential curve fits were consistently found to be statistically accurate least-square fit representations of the raw data recovery values. The predictive procedures used here were multivariate regression analyses, which are applicable to soils at a variety of depths besides the 10-cm depth presented.

  2. Projected impact of the ICD-10-CM/PCS conversion on longitudinal data and the Joint Commission Core Measures.

    PubMed

    Fenton, Susan H; Benigni, Mary Sue

    2014-01-01

    The transition from ICD-9-CM to ICD-10-CM/PCS is expected to result in longitudinal data discontinuities, as occurred with cause-of-death in 1999. The General Equivalence Maps (GEMs), while useful for suggesting potential maps do not provide guidance regarding the frequency of any matches. Longitudinal data comparisons can only be reliable if they use comparability ratios or factors which have been calculated using records coded in both classification systems. This study utilized 3,969 de-identified dually coded records to examine raw comparability ratios, as well as the comparability ratios between the Joint Commission Core Measures. The raw comparability factor results range from 16.216 for Nicotine dependence, unspecified, uncomplicated to 118.009 for Chronic obstructive pulmonary disease, unspecified. The Joint Commission Core Measure comparability factor results range from 27.15 for Acute Respiratory Failure to 130.16 for Acute Myocardial Infarction. These results indicate significant differences in comparability between ICD-9-CM and ICD-10-CM code assignment, including when the codes are used for external reporting such as the Joint Commission Core Measures. To prevent errors in decision-making and reporting, all stakeholders relying on longitudinal data for measure reporting and other purposes should investigate the impact of the conversion on their data.

  3. Illusory Tactile Motion Perception: An Analog of the Visual Filehne Illusion

    PubMed Central

    Moscatelli, Alessandro; Hayward, Vincent; Wexler, Mark; Ernst, Marc O.

    2015-01-01

    We continually move our body and our eyes when exploring the world, causing our sensory surfaces, the skin and the retina, to move relative to external objects. In order to estimate object motion consistently, an ideal observer would transform estimates of motion acquired from the sensory surface into fixed, world-centered estimates, by taking the motion of the sensor into account. This ability is referred to as spatial constancy. Human vision does not follow this rule strictly and is therefore subject to perceptual illusions during eye movements, where immobile objects can appear to move. Here, we investigated whether one of these, the Filehne illusion, had a counterpart in touch. To this end, observers estimated the movement of a surface from tactile slip, with a moving or with a stationary finger. We found the perceived movement of the surface to be biased if the surface was sensed while moving. This effect exemplifies a failure of spatial constancy that is similar to the Filehne illusion in vision. We quantified this illusion by using a Bayesian model with a prior for stationarity, applied previously in vision. The analogy between vision and touch points to a modality-independent solution to the spatial constancy problem. PMID:26412592

  4. Illusory Tactile Motion Perception: An Analog of the Visual Filehne Illusion.

    PubMed

    Moscatelli, Alessandro; Hayward, Vincent; Wexler, Mark; Ernst, Marc O

    2015-09-28

    We continually move our body and our eyes when exploring the world, causing our sensory surfaces, the skin and the retina, to move relative to external objects. In order to estimate object motion consistently, an ideal observer would transform estimates of motion acquired from the sensory surface into fixed, world-centered estimates, by taking the motion of the sensor into account. This ability is referred to as spatial constancy. Human vision does not follow this rule strictly and is therefore subject to perceptual illusions during eye movements, where immobile objects can appear to move. Here, we investigated whether one of these, the Filehne illusion, had a counterpart in touch. To this end, observers estimated the movement of a surface from tactile slip, with a moving or with a stationary finger. We found the perceived movement of the surface to be biased if the surface was sensed while moving. This effect exemplifies a failure of spatial constancy that is similar to the Filehne illusion in vision. We quantified this illusion by using a Bayesian model with a prior for stationarity, applied previously in vision. The analogy between vision and touch points to a modality-independent solution to the spatial constancy problem.

  5. Effect of Home Exercise Program Performance in Patients with Osteoarthritis of the Knee or the Spine on the Visual Analog Scale after Discharge from Physical Therapy

    ERIC Educational Resources Information Center

    Chen, Hamilton; Onishi, Kentaro

    2012-01-01

    The aim of our study was to assess the effect of the frequency of home exercise program (HEP) performance on pain [10-point visual analog scale (VAS)] in patients with osteoarthritis of the spine or knee after more than 6 months discharge from physical therapy (PT). We performed a retrospective chart review of 48 adult patients with a clinical…

  6. Evaluation of the effect of laser acupuncture and cupping with ryodoraku and visual analog scale on low back pain.

    PubMed

    Lin, Mu-Lien; Wu, Hung-Chien; Hsieh, Ya-Hui; Su, Chuan-Tsung; Shih, Yong-Sheng; Lin, Chii-Wann; Wu, Jih-Huah

    2012-01-01

    The purpose of this study was to evaluate the effect of laser acupuncture (LA) and soft cupping on low back pain. In this study, the subjects were randomly assigned to two groups: active group (real LA and soft cupping) and placebo group (sham laser and soft cupping). Visual analog scale (VAS) and Ryodoraku were used to evaluate the effect of treatment on low back pain in this trial. Laser, 40 mW, wavelength 808 nm, pulse rate 20 Hz, was used to irradiate Weizhong (BL40) and Ashi acupoints for 10 minutes. And the Ryodoraku values were measured 2 times, that is, before and 15 minutes after treatment. The results show that there were significant difference between the first day baseline and the fifth day treatment in VAS in the two groups. Therefore, LA combined with soft cupping or only soft cupping was effective on low back pain. However, the Ryodoraku values of Bladder Meridian of the placebo group have been decreased apparently, and didn't come back to their original values. It means that "cupping" plays the role of "leak or purge" in traditional Chinese medicine (TCM). On the other hand, the Ryodoraku values of Bladder Meridian of the active group have been turned back to almost their original values; "mend or reinforcing" effect is attributed to the laser radiation.

  7. Evaluation of the Effect of Laser Acupuncture and Cupping with Ryodoraku and Visual Analog Scale on Low Back Pain

    PubMed Central

    Lin, Mu-Lien; Wu, Hung-Chien; Hsieh, Ya-Hui; Su, Chuan-Tsung; Shih, Yong-Sheng; Lin, Chii-Wann; Wu, Jih-Huah

    2012-01-01

    The purpose of this study was to evaluate the effect of laser acupuncture (LA) and soft cupping on low back pain. In this study, the subjects were randomly assigned to two groups: active group (real LA and soft cupping) and placebo group (sham laser and soft cupping). Visual analog scale (VAS) and Ryodoraku were used to evaluate the effect of treatment on low back pain in this trial. Laser, 40 mW, wavelength 808 nm, pulse rate 20 Hz, was used to irradiate Weizhong (BL40) and Ashi acupoints for 10 minutes. And the Ryodoraku values were measured 2 times, that is, before and 15 minutes after treatment. The results show that there were significant difference between the first day baseline and the fifth day treatment in VAS in the two groups. Therefore, LA combined with soft cupping or only soft cupping was effective on low back pain. However, the Ryodoraku values of Bladder Meridian of the placebo group have been decreased apparently, and didn't come back to their original values. It means that “cupping” plays the role of “leak or purge” in traditional Chinese medicine (TCM). On the other hand, the Ryodoraku values of Bladder Meridian of the active group have been turned back to almost their original values; “mend or reinforcing” effect is attributed to the laser radiation. PMID:23118792

  8. In-situ determination of astro-comb calibrator lines to better than 10 cm s(-1).

    PubMed

    Li, Chih-Hao; Glenday, Alexander G; Benedick, Andrew J; Chang, Guoqing; Chen, Li-Jin; Cramer, Claire; Fendel, Peter; Furesz, Gabor; Kärtner, Franz X; Korzennik, Sylvain; Phillips, David F; Sasselov, Dimitar; Szentgyorgyi, Andrew; Walsworth, Ronald L

    2010-06-07

    Improved wavelength calibrators for high-resolution astrophysical spectrographs will be essential for precision radial velocity (RV) detection of Earth-like exoplanets and direct observation of cosmological deceleration. The astro-comb is a combination of an octave-spanning femtosecond laser frequency comb and a Fabry-Pérot cavity used to achieve calibrator line spacings that can be resolved by an astrophysical spectrograph. Systematic spectral shifts associated with the cavity can be 0.1-1 MHz, corresponding to RV errors of 10-100 cm/s, due to the dispersive properties of the cavity mirrors over broad spectral widths. Although these systematic shifts are very stable, their correction is crucial to high accuracy astrophysical spectroscopy. Here, we demonstrate an in-situ technique to determine the systematic shifts of astro-comb lines due to finite Fabry-Pérot cavity dispersion. The technique is practical for implementation at a telescope-based spectrograph to enable wavelength calibration accuracy better than 10 cm/s.

  9. Verbal numerical scales are as reliable and sensitive as visual analog scales for rating dyspnea in young and older subjects.

    PubMed

    Morris, N R; Sabapathy, S; Adams, L; Kingsley, R A; Schneider, D A; Stulbarg, M S

    2007-08-01

    This study compared the use of a simple verbal 0-10 numerical rating scale (verbal NRS) and a visual analog scale (VAS) for the rating of dyspnea during exercise in a group of young and older subjects. Twelve younger (32+/-9 yr) and 12 older (71+/-7 yr) subjects used either the verbal NRS or the VAS in a randomised fashion to rate dyspnea during 60 s of uphill treadmill walking (range 5.6-8.8 km h(-1)) performed at either a low (17% grade) or high workload (26% grade) and then during recovery. Rating scales were evaluated twice on separate days (day 1 and day 2) at each workload. While the verbal NRS scores proved to be reliable throughout exercise and recovery, VAS scores were significantly (p<0.05) lower on day 2 during the low workload test (younger group) and the high workload test (older group). Verbal NRS ratings were consistently greater than VAS ratings at both workloads (p<0.001) for both young and older groups. The intra-class correlation coefficients for rating peak dyspnea using either the VAS or verbal NRS were consistently lower for the older subjects (range: r=0.54-0.67) than the younger subjects (range: r=0.70-0.86). Overall, subjects preferred the verbal NRS to the VAS. These results suggest that the verbal NRS compares favourably with the VAS for rating dyspnea during exercise without mask or mouthpiece. However, when rating peak dyspnea both scales appear less reliable when used by the older compared to young subjects.

  10. A Phase II Multicenter Trial With Rivaroxaban in the Treatment of Livedoid Vasculopathy Assessing Pain on a Visual Analog Scale

    PubMed Central

    Drabik, Attyla; Hillgruber, Carina

    2014-01-01

    Background Livedoid vasculopathy is an orphan skin disease characterized by recurrent thrombosis of the cutaneous microcirculation. It manifests itself almost exclusively in the ankles, the back of the feet, and the distal part of the lower legs. Because of the vascular occlusion, patients suffer from intense local ischemic pain. Incidence of livedoid vasculopathy is estimated to be around 1:100,000. There are currently no approved treatments for livedoid vasculopathy, making off-label therapy the only option. In Europe, thromboprophylactic treatment with low-molecular-weight heparins has become widely accepted. Objective The aim of this trial is the statistical verification of the therapeutic effects of the anticoagulant rivaroxaban in patients suffering from livedoid vasculopathy. Methods We performed a therapeutic phase IIa trial designed as a prospective, one-armed, multicenter, interventional series of cases with a calculated sample size of 20 patients. The primary outcome is the assessment of local pain on the visual analog scale (VAS) as an intraindividual difference of 2 values between baseline and 12 weeks. Results Enrollment started in December 2012 and was still open at the date of submission. The study is expected to finish in November 2014. Conclusions Livedoid vasculopathy is associated with increased thrombophilia in the cutaneous microcirculation and the continuous use of anticoagulants helps improve the symptoms. The causes of cutaneous infarctions are heterogenous, but ultimately follow the known mechanisms of the coagulation cascade. Rivaroxaban affects the coagulation cascade and inhibits the factor Xa–dependent conversion of prothrombin to thrombin, thereby considerably reducing the risk of thrombosis. Trial Registration Trial Registration EudraCT Number: 2012-000108-13-DE; https://www.clinicaltrialsregister.eu/ctr-search/search?query=eudract_number:2012-000108-13 (Archived by WebCite at http://www.webcitation.org/6UCktWVCA); German Clinical

  11. ICD-9-CM and ICD-10-CM mapping of the AAST Emergency General Surgery disease severity grading systems: Conceptual approach, limitations, and recommendations for the future.

    PubMed

    Utter, Garth H; Miller, Preston R; Mowery, Nathan T; Tominaga, Gail T; Gunter, Oliver; Osler, Turner M; Ciesla, David J; Agarwal, Suresh K; Inaba, Kenji; Aboutanos, Michel B; Brown, Carlos V R; Ross, Steven E; Crandall, Marie L; Shafi, Shahid

    2015-05-01

    The American Association for the Surgery of Trauma (AAST) recently established a grading system for uniform reporting of anatomic severity of several emergency general surgery (EGS) diseases. There are five grades of severity for each disease, ranging from I (lowest severity) to V (highest severity). However, the grading process requires manual chart review. We sought to evaluate whether International Classification of Diseases, 9th and 10th Revisions, Clinical Modification (ICD-9-CM, ICD-10-CM) codes might allow estimation of AAST grades for EGS diseases. The Patient Assessment and Outcomes Committee of the AAST reviewed all available ICD-9-CM and ICD-10-CM diagnosis codes relevant to 16 EGS diseases with available AAST grades. We then matched grades for each EGS disease with one or more ICD codes. We used the Official Coding Guidelines for ICD-9-CM and ICD-10-CM and the American Hospital Association's "Coding Clinic for ICD-9-CM" for coding guidance. The ICD codes did not allow for matching all five AAST grades of severity for each of the 16 diseases. With ICD-9-CM, six diseases mapped into four categories of severity (instead of five), another six diseases into three categories of severity, and four diseases into only two categories of severity. With ICD-10-CM, five diseases mapped into four categories of severity, seven diseases into three categories, and four diseases into two categories. Two diseases mapped into discontinuous categories of grades (two in ICD-9-CM and one in ICD-10-CM). Although resolution is limited, ICD-9-CM and ICD-10-CM diagnosis codes might have some utility in roughly approximating the severity of the AAST grades in the absence of more precise information. These ICD mappings should be validated and refined before widespread use to characterize EGS disease severity. In the long-term, it may be desirable to develop alternatives to ICD-9-CM and ICD-10-CM codes for routine collection of disease severity characteristics.

  12. Hydraulic Capacitor Analogy

    ERIC Educational Resources Information Center

    Baser, Mustafa

    2007-01-01

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

  13. HIPAA administrative simplification: modifications to medical data code set standards to adopt ID-10-CM and ICD-10-PCS. Final rule.

    PubMed

    2009-01-16

    This final rule adopts modifications to two of the code set standards adopted in the Transactions and Code Sets final rule published in the Federal Register pursuant to certain provisions of the Administrative Simplification subtitle of the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Specifically, this final rule modifies the standard medical data code sets (hereinafter "code sets") for coding diagnoses and inpatient hospital procedures by concurrently adopting the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) for diagnosis coding, including the Official ICD-10-CM Guidelines for Coding and Reporting, as maintained and distributed by the U.S. Department of Health and Human Services (HHS), hereinafter referred to as ICD-10-CM, and the International Classification of Diseases, 10th Revision, Procedure Coding System (ICD-10-PCS) for inpatient hospital procedure coding, including the Official ICD-10-PCS Guidelines for Coding and Reporting, as maintained and distributed by the HHS, hereinafter referred to as ICD-10-PCS. These new codes replace the International Classification of Diseases, 9th Revision, Clinical Modification, Volumes 1 and 2, including the Official ICD-9-CM Guidelines for Coding and Reporting, hereinafter referred to as ICD-9-CM Volumes 1 and 2, and the International Classification of Diseases, 9th Revision, Clinical Modification, Volume 3, including the Official ICD-9-CM Guidelines for Coding and Reporting, hereinafter referred to as ICD-9-CM Volume 3, for diagnosis and procedure codes, respectively.

  14. Proposed Framework for Presenting Injury Data Using the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) Diagnosis Codes.

    PubMed

    Hedegaard, Holly; Johnson, Renee L; Warner, Margaret; Chen, Li-Hui; Annest, J Lee

    2016-01-22

    Frameworks based on the International Classification of Diseases (ICD) provide injury researchers and epidemiologists with standard approaches for presenting and analyzing injury-related mortality and morbidity data. Injury diagnosis frameworks, such as the Barell Matrix for the ICD Ninth Revision, Clinical Modification (ICD-9-CM) and the Injury Mortality Diagnosis Matrix for the ICD Tenth Revision (ICD-10), categorize ICD codes into major body region (e.g., head, chest, abdomen, or extremity) by nature-of-injury (e.g., fracture, laceration, organ injury, or vascular injury) categories. In the United States, morbidity coding transitioned from ICD-9- CM to ICD-10-CM on October 1, 2015. In preparation for the use of ICD-10-CMcoded morbidity data for injury surveillance and data analysis, the National Center for Health Statistics and the National Center for Injury Prevention and Control propose an ICD-10-CM Injury Diagnosis Matrix to provide a standard approach for categorizing injuries by body region and nature of injury. This report provides a brief description of the differences between ICD-9-CM and ICD-10-CM injury diagnosis codes, introduces the proposed framework and the methods used to create it, and provides a list of additional considerations for review and comment by researchers and subjectmatter experts in injury data and surveillance.

  15. Dynamics of cell and tissue growth acquired by means of 25 mm2 to 10 cm2 lens-free imaging

    NASA Astrophysics Data System (ADS)

    Momey, F.; Coutard, J.-G.; Bordy, T.; Navarro, F.; Menneteau, M.; Dinten, J.-M.; Allier, C.

    2015-03-01

    In this paper, we discuss a new methodology based on lens-free imaging to perform wound healing assay with unprecedented statistics. Our video lens-free microscopy setup is a simple optical system featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful means for the real-time monitoring of cultivated cells. It presents several key advantages, e.g., integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm2) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. But in the case of tissue growth experiments, the field of view of 25 mm2 remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assay, here we propose to enlarge the field of view up to 10 cm2 through two different approaches. The first method consists in performing a scan of the cell culture by moving the source/sensor couple and then stitch the stack of images. The second is to make an acquisition by scanning with a line scan camera. The two approaches are compared in term of resolution, complexity and acquisition time. Next we have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm2) and in final point (10 cm2) to assess the combination of these two complementary modalities. In the future, we aim at combining directly super wide field of view acquisitions (>10 cm2) with real time ability inside the incubator.

  16. Lunar Analog

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita L.

    2009-01-01

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

  17. Analysis of disease-dependent sedative profiles of H(1)-antihistamines by large-scale surveillance using the visual analog scale.

    PubMed

    Izumi, N; Mizuguchi, H; Umehara, H; Ogino, S; Fukui, H

    2008-04-01

    Sedation is the most frequent side effect of H(1)-antihistamines, and, sometimes, it may be life-threatening for patients. Evaluation of the sedative properties of H(1)-antihistamines is important to improve the patients' quality of life (QOL). Therefore, we carried out a large-scale surveillance quantified through a questionnaire using visual analog scale (VAS) from 1,742 patients. The results showed that the degree of sleepiness caused by some nonsedative second-generation antihistamines, including fexofenadine, olopatadine and cetirizine, was disease dependent. In atopic dermatitis, an unexpectedly low VAS score of sleepiness was obtained for the first-generation antihistamine d-chlorpheniramine, which is similar to those obtained for bepotastine and epinastine. d-Chlorpheniramine also showed a high VAS score in efficacy. Meanwhile, fexofenadine showed a higher VAS score of sleepiness in atopic dermatitis than those obtained in the other allergic diseases including allergic rhinitis, urticaria and asthma. In asthma, a higher VAS score of sleepiness was found for olopatadine, ebastine and cetirizine, when compared with d-chlorpheniramine. On the other hand, bepotastine showed the lowest VAS score for sleepiness. Our findings suggest the existence of unknown factors influencing the sedative properties of H(1)-antihistamines. Therefore, appropriate H(1)-antihistamines may need to be selected, depending on allergic diseases, to improve patients' QOL.

  18. Effect of a combined continuous and intermittent transcutaneous electrical nerve stimulation on pain perception of burn patients evaluated by visual analog scale: a pilot study

    PubMed Central

    Pérez-Ruvalcaba, Irma; Sánchez-Hernández, Viridiana; Mercado-Sesma, Arieh R

    2015-01-01

    Aim The aim of this study was to assess the effect of continuous and intermittent electrical transcutaneous nerve stimulation on the perception of pain in patients with burns of different types. Materials and methods A pilot study was conducted in 14 patients (age 30.9±7.5 years) with second- and third-degree burns of different types. The burn types included electrical, fire/flame, and chemical. All patients received continuous and intermittent electrical transcutaneous nerve stimulation sessions three times per week for 4 weeks. Each session had a duration of 30 minutes. A pair of electrodes were placed around the burn. The primary efficacy endpoint was the perception of pain assessed by a visual analog scale at baseline and at the 30th day. Results A significant reduction of pain perception was reported (8.0±1.7 vs 1.0±0.5; P=0.027) by all patients after electrical stimulation therapy. There were no reports of adverse events during the intervention period. Conclusion Electrical stimulation could be a potential nonpharmacological therapeutic option for pain management in burn patients. PMID:26719723

  19. Arterial Pressure Analog.

    ERIC Educational Resources Information Center

    Heusner, A. A.; Tracy, M. L.

    1980-01-01

    Describes a simple hydraulic analog which allows students to explore some physical aspects of the cardiovascular system and provides them with a means to visualize and conceptualize these basic principles. Simulates the behavior of arterial pressure in response to changes in heart rate, stroke volume, arterial compliance, and peripheral…

  20. Endovascular Treatment of Pelvic Congestion Syndrome: Visual Analog Scale (VAS) Long-Term Follow-up Clinical Evaluation in 202 Patients

    SciTech Connect

    Laborda, Alicia Medrano, Joaquin; Blas, Ignacio de; Urtiaga, Ignacio; Carnevale, Francisco Cesar; Gregorio, Miguel A. de

    2013-08-01

    PurposeThis study was designed to evaluate the clinical outcome and patients' satisfaction after a 5 year follow-up period for pelvic congestion syndrome (PCS) coil embolization in patients who suffered from chronic pelvic pain that initially consulted for lower limb venous insufficiency.MethodsA total of 202 patients suffering from chronic pelvic pain were recruited prospectively in a single center (mean age 43.5 years; range 27-57) where they were being treated for lower limb varices. Inclusion criteria were: lower limb varices and chronic pelvic pain (>6 months), >6 mm pelvic venous caliber in ultrasonography, and venous reflux or presence of communicating veins. Both ovarian and hypogastric veins were targeted for embolization. Pain level was assessed before and after embolotherapy and during follow-up using a visual analog scale (VAS). Technical and clinical success and recurrence of leg varices were studied. Patients completed a quality questionnaire. Clinical follow-up was performed at 1, 3, and 6 months and every year for 5 years.ResultsTechnical success was 100 %. Clinical success was achieved in 168 patients (93.85 %), with complete disappearance of symptoms in 60 patients (33.52 %). Pain score (VAS) was 7.34 {+-} 0.7 preprocedural versus 0.78 {+-} 1.2 at the end of follow-up (P < 0.0001). Complications were: groin hematoma (n = 6), coil migration (n = 4), and reaction to contrast media (n = 1). Twenty-three cases presented abdominal pain after procedure. In 24 patients (12.5 %), there was recurrence of their leg varices within the follow-up. The mean degree of patients' satisfaction was 7.4/9.ConclusionsCoil embolization of PCS is an effective and safe procedure, with high clinical success rate and degree of satisfaction.

  1. VIIP Bedrest Analog Roadmap

    NASA Technical Reports Server (NTRS)

    Villarreal, Jennifer D.

    2014-01-01

    The objective is to define successive bed rest campaigns leading to a potential VIIP (Vision Impairment and Intracranial Pressure) countermeasure. To determine if the analog is successful, changes need to occur in the following outcome measures (dependent variables): Intracranial pressure; Retinal nerve fiber layer; Choroidal engorgement; Globe flattening; Axial biometry; Optic nerve sheath diameter distention; Cycloplegic refraction; Visual acuity. Study parameters (independent variables) to include: CO2; Sodium; Exercise (resistive & aerobic); Strict tilt angle.

  2. Analog earthquakes

    SciTech Connect

    Hofmann, R.B.

    1995-09-01

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

  3. Triptycene analogs

    NASA Technical Reports Server (NTRS)

    Hua, Duy (Inventor); Perchellet, Jean-Pierre (Inventor)

    2004-01-01

    This invention provides analogs of triptycene which are useful as anticancer drugs, as well as for other uses. The potency of these compounds is in a similar magnitude as daunomycin, a currently used anticancer drug. Each compound of the invention produces one or more desired effects (blocking nucleoside transport, inhibiting nucleic acid or protein syntheses, decreasing the proliferation and viability of cancer cells, inducing DNA fragmentation or retaining their effectiveness against multidrug-resistant tumor cells).

  4. Cyber Analogies

    DTIC Science & Technology

    2014-02-28

    including the time for reviewing instructions , searching existing data sources, gathering and maintaining the data needed, and completing and reviewing... CONTENTS 1 Introduction Emily O. Goldman & John Arquilla 7 The Cyber Pearl Harbor James J. Wirtz 15 Applying the Historical Lessons of Surprise Attack...As H.G. Wells put it, “History is a race between education and catastrophe.” SURPRISE ATTACK The primarily history- based analogies contained herein

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

    ERIC Educational Resources Information Center

    Friedel, Arthur W.; And Others

    1990-01-01

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

  6. Genomics Analogy Model for Educators (GAME): Fuzzy DNA Model to Enable the Learning of Gene Sequencing by Visually-Impaired and Blind Students

    ERIC Educational Resources Information Center

    Butler, Charles; Bello, Julia; York, Alan; Orvis, Kathryn; Pittendrigh, Barry R.

    2008-01-01

    Much of the general population is aware of terms such as biotechnology, genetic engineering, and genomics. However, there is a lack of understanding concerning these fields among many secondary school students. Few teaching models exist to explain concepts behind genomics and even less are available for teaching the visually impaired and blind.…

  7. Administrative simplification: change to the compliance date for the International Classification of Diseases, 10th Revision (ICD-10-CM and ICD-10-PCS) medical data code sets. Final rule.

    PubMed

    2014-08-04

    This final rule implements section 212 of the Protecting Access to Medicare Act of 2014 by changing the compliance date for the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) for diagnosis coding, including the Official ICD-10-CM Guidelines for Coding and Reporting, and the International Classification of Diseases, 10th Revision, Procedure Coding System (ICD-10-PCS) for inpatient hospital procedure coding, including the Official ICD-10-PCS Guidelines for Coding and Reporting, from October 1, 2014 to October 1, 2015. It also requires the continued use of the International Classification of Diseases, 9th Revision, Clinical Modification, Volumes 1 and 2 (diagnoses), and 3 (procedures) (ICD-9-CM), including the Official ICD-9-CM Guidelines for Coding and Reporting, through September 30, 2015.

  8. Analog current mode analog/digital converter

    NASA Technical Reports Server (NTRS)

    Hadidi, Khayrollah (Inventor)

    1996-01-01

    An improved subranging or comparator circuit is provided for an analog-to-digital converter. As a subranging circuit, the circuit produces a residual signal representing the difference between an analog input signal and an analog of a digital representation. This is achieved by subdividing the digital representation into two or more parts and subtracting from the analog input signal analogs of each of the individual digital portions. In another aspect of the present invention, the subranging circuit comprises two sets of differential input pairs in which the transconductance of one differential input pair is scaled relative to the transconductance of the other differential input pair. As a consequence, the same resistor string may be used for two different digital-to-analog converters of the subranging circuit.

  9. Expert analogy use in a naturalistic setting

    PubMed Central

    Kretz, Donald R.; Krawczyk, Daniel C.

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Orgill, Marykay

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

  11. Learning by Analogy: Discriminating between Potential Analogs

    ERIC Educational Resources Information Center

    Richland, Lindsey E.; McDonough, Ian M.

    2010-01-01

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

  12. A Computer-Based Visual Analog Scale,

    DTIC Science & Technology

    1992-06-01

    Watkins, L.R., and Buckingham, B., "Psychophysical Analysis of Acupuncture Analgesia." Pain, Vol. 19, pp. 27-42, 1984. 9. Rafl, T.W., "Central Nervous...Restlessness Tremor (shaking) Headache ,,Diarrhea Constipation Abdominal cramps Dry mouth Unpleasant taste Urticaria ( itching ) Fatigue Depression

  13. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  14. The Analogical Mind.

    ERIC Educational Resources Information Center

    Holyoak, Keith J.; Thagard, Paul

    1997-01-01

    The use of analogy in human thinking is examined from the perspective of a multiconstraint theory that postulates similarity, structure, and purpose as three kinds of constraints. The theory has been implemented in computational simulations of the analogical human mind using the Analogical Mapping by Constraint Satisfaction (ACME) model. (SLD)

  15. Analog without fear

    NASA Technical Reports Server (NTRS)

    Delagrange, A. D.

    1977-01-01

    Analog circuitry, also referred to as Linear, has been nearly run over by the digital/computer bandwagon. This is unfortunate because tremendous advances are being made in the field of analog integrated circuitry. Each year's progress raises the state-of-the-art, bringing achievements not possible even the year before. Many of the traditional prejudices against analog circuitry are no longer valid. This report attempts to summarize what is available now and what can (and can't) be done with analog integrated circuitry.

  16. Analog synthetic biology.

    PubMed

    Sarpeshkar, R

    2014-03-28

    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.

  17. Nonvolatile Analog Memory

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd C. (Inventor)

    2007-01-01

    A nonvolatile analog memory uses pairs of ferroelectric field effect transistors (FFETs). Each pair is defined by a first FFET and a second FFET. When an analog value is to be stored in one of the pairs, the first FFET has a saturation voltage applied thereto, and the second FFET has a storage voltage applied thereto that is indicative of the analog value. The saturation and storage voltages decay over time in accordance with a known decay function that is used to recover the original analog value when the pair of FFETs is read.

  18. Challenges in Using Analogies

    ERIC Educational Resources Information Center

    Lin, Shih-Yin; Singh, Chandralekha

    2011-01-01

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

  19. Analogies for Avogadro's Number.

    ERIC Educational Resources Information Center

    Poskozim, Paul S.; And Others

    1986-01-01

    Reviews analogies used to try to capture the concept of the magnitude of Avogadro's number, including analogies related to small/tiny objects, counting, people, water, and money. Also presents several new ones which are based on modern computers and printers. (JN)

  20. Analog pulse processor

    DOEpatents

    Wessendorf, Kurt O.; Kemper, Dale A.

    2003-06-03

    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.

  1. Meat analog: a review.

    PubMed

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

    2015-01-01

    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.

  2. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  3. Challenges in Using Analogies

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-11-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features.1-7 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.

  4. FGF growth factor analogs

    DOEpatents

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

    2012-07-24

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

  5. Electrical Circuits and Water Analogies

    ERIC Educational Resources Information Center

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

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

  6. Is the link from working memory to analogy causal? No analogy improvements following working memory training gains.

    PubMed

    Richey, J Elizabeth; Phillips, Jeffrey S; Schunn, Christian D; Schneider, Walter

    2014-01-01

    Analogical reasoning has been hypothesized to critically depend upon working memory through correlational data, but less work has tested this relationship through experimental manipulation. An opportunity for examining the connection between working memory and analogical reasoning has emerged from the growing, although somewhat controversial, body of literature suggests complex working memory training can sometimes lead to working memory improvements that transfer to novel working memory tasks. This study investigated whether working memory improvements, if replicated, would increase analogical reasoning ability. We assessed participants' performance on verbal and visual analogy tasks after a complex working memory training program incorporating verbal and spatial tasks. Participants' improvements on the working memory training tasks transferred to other short-term and working memory tasks, supporting the possibility of broad effects of working memory training. However, we found no effects on analogical reasoning. We propose several possible explanations for the lack of an impact of working memory improvements on analogical reasoning.

  7. Digital and analog communication systems

    NASA Technical Reports Server (NTRS)

    Shanmugam, K. S.

    1979-01-01

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

  8. Analogical Reasoning in Geometry Education

    ERIC Educational Resources Information Center

    Magdas, Ioana

    2015-01-01

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

  9. Electrical analogous in viscoelasticity

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    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. Analog Optical Links

    NASA Astrophysics Data System (ADS)

    Cox, Charles H., III

    2004-05-01

    Unlike books that focus on the devices used in links, such as lasers and photodiodes, among others, this text focuses on the next level. It covers the collection of devices that form a link, how the individual device performance affects the link performance, or the reverse. Analog links are used for the distribution of cable TV signals, and in conveying the signals to and from antennas (so called antenna remoting). The design of analog links differs significantly from digital links which are primarily used in telecommunications.

  11. Semantics by analogy for illustrative volume visualization☆

    PubMed Central

    Gerl, Moritz; Rautek, Peter; Isenberg, Tobias; Gröller, Eduard

    2012-01-01

    We present an interactive graphical approach for the explicit specification of semantics for volume visualization. This explicit and graphical specification of semantics for volumetric features allows us to visually assign meaning to both input and output parameters of the visualization mapping. This is in contrast to the implicit way of specifying semantics using transfer functions. In particular, we demonstrate how to realize a dynamic specification of semantics which allows to flexibly explore a wide range of mappings. Our approach is based on three concepts. First, we use semantic shader augmentation to automatically add rule-based rendering functionality to static visualization mappings in a shader program, while preserving the visual abstraction that the initial shader encodes. With this technique we extend recent developments that define a mapping between data attributes and visual attributes with rules, which are evaluated using fuzzy logic. Second, we let users define the semantics by analogy through brushing on renderings of the data attributes of interest. Third, the rules are specified graphically in an interface that provides visual clues for potential modifications. Together, the presented methods offer a high degree of freedom in the specification and exploration of rule-based mappings and avoid the limitations of a linguistic rule formulation. PMID:23576827

  12. Reasoning through Instructional Analogies

    ERIC Educational Resources Information Center

    Kapon, Shulamit; diSessa, Andrea A.

    2012-01-01

    This article aims to account for students' assessments of the plausibility and applicability of analogical explanations, and individual differences in these assessments, by analyzing properties of students' underlying knowledge systems. We developed a model of explanation and change in explanation focusing on knowledge elements that provide a…

  13. An Interesting Analogy

    ERIC Educational Resources Information Center

    Pacheco, Jose M.; Fernandez, Isabel

    2002-01-01

    The aim of this note is to give some insight into the formal unity of a very applicable area of mathematics by showing an interesting analogy between the weak part of the Rouche-Frobenius theorem and the existence result for the initial value problem for the general first-order linear two-dimensional PDE.

  14. Analogy, explanation, and proof.

    PubMed

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

    2014-01-01

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

  15. Quantum Analog Computing

    NASA Technical Reports Server (NTRS)

    Zak, M.

    1998-01-01

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

  16. Are Scientific Analogies Metaphors?

    DTIC Science & Technology

    1981-02-01

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

  17. Analogy, explanation, and proof

    PubMed Central

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

    2014-01-01

    People are habitual explanation generators. At its most mundane, our propensity to explain allows us to infer that we should not drink milk that smells sour; at the other extreme, it allows us to establish facts (e.g., theorems in mathematical logic) whose truth was not even known prior to the existence of the explanation (proof). What do the cognitive operations underlying the inference that the milk is sour have in common with the proof that, say, the square root of two is irrational? Our ability to generate explanations bears striking similarities to our ability to make analogies. Both reflect a capacity to generate inferences and generalizations that go beyond the featural similarities between a novel problem and familiar problems in terms of which the novel problem may be understood. However, a notable difference between analogy-making and explanation-generation is that the former is a process in which a single source situation is used to reason about a single target, whereas the latter often requires the reasoner to integrate multiple sources of knowledge. This seemingly small difference poses a challenge to the task of marshaling our understanding of analogical reasoning to understanding explanation. We describe a model of explanation, derived from a model of analogy, adapted to permit systematic violations of this one-to-one mapping constraint. Simulation results demonstrate that the resulting model can generate explanations for novel explananda and that, like the explanations generated by human reasoners, these explanations vary in their coherence. PMID:25414655

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

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  19. Terrestrial Spaceflight Analogs: Antarctica

    NASA Technical Reports Server (NTRS)

    Crucian, Brian

    2013-01-01

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

  20. Analog storage integrated circuit

    DOEpatents

    Walker, J. T.; Larsen, R. S.; Shapiro, S. L.

    1989-01-01

    A high speed data storage array is defined utilizing a unique cell design for high speed sampling of a rapidly changing signal. Each cell of the array includes two input gates between the signal input and a storage capacitor. The gates are controlled by a high speed row clock and low speed column clock so that the instantaneous analog value of the signal is only sampled and stored by each cell on coincidence of the two clocks.

  1. Antarctic analogs for Enceladus

    NASA Astrophysics Data System (ADS)

    Murray, A. E.; Andersen, D. T.; McKay, C. P.

    2014-12-01

    Enceladus is a new world for Astrobiology. The Cassini discovery of the icy plume emanating from the South Polar region indicates an active world, where detection of water, organics, sodium, and nano-particle silica in the plume strongly suggests that the source is a subsurface salty ocean reservoir. Recent gravity data from Cassini confirms the presence of a regional sea extending north to 50°S. An ocean habitat under a thick ice cover is perhaps a recurring theme in the Outer Solar System, but what makes Enceladus unique is that the plume jetting out into space is carrying samples of this ocean. Therefore, through the study of Enceladus' plumes we can gain new insights not only of a possible habitable world in the Solar Systems, but also about the formation and evolution of other icy-satellites. Cassini has been able to fly through this plume - effectively sampling the ocean. It is time to plan for future missions that do more detailed analyses, possibly return samples back to Earth and search for evidence of life. To help prepare for such missions, the need for earth-based analog environments is essential for logistical, methodological (life detection) and theoretical development. We have undertaken studies of two terrestrial environments that are close analogs to Enceladus' ocean: Lake Vida and Lake Untersee - two ice-sealed Antarctic lakes that represent physical, chemical and possibly biological analogs for Enceladus. By studying the diverse biology and physical and chemical constraints to life in these two unique lakes we will begin to understand the potential habitability of Enceladus and other icy moons, including possible sources of nutrients and energy, which together with liquid water are the key ingredients for life. Analog research such as this will also enable us to develop and test new strategies to search for evidence of life on Enceladus.

  2. Analog storage integrated circuit

    DOEpatents

    Walker, J.T.; Larsen, R.S.; Shapiro, S.L.

    1989-03-07

    A high speed data storage array is defined utilizing a unique cell design for high speed sampling of a rapidly changing signal. Each cell of the array includes two input gates between the signal input and a storage capacitor. The gates are controlled by a high speed row clock and low speed column clock so that the instantaneous analog value of the signal is only sampled and stored by each cell on coincidence of the two clocks. 6 figs.

  3. A Transiting Jupiter Analog

    NASA Astrophysics Data System (ADS)

    Kipping, D. M.; Torres, G.; Henze, C.; Teachey, A.; Isaacson, H.; Petigura, E.; Marcy, G. W.; Buchhave, L. A.; Chen, J.; Bryson, S. T.; Sandford, E.

    2016-04-01

    Decadal-long radial velocity surveys have recently started to discover analogs to the most influential planet of our solar system, Jupiter. Detecting and characterizing these worlds is expected to shape our understanding of our uniqueness in the cosmos. Despite the great successes of recent transit surveys, Jupiter analogs represent a terra incognita, owing to the strong intrinsic bias of this method against long orbital periods. We here report on the first validated transiting Jupiter analog, Kepler-167e (KOI-490.02), discovered using Kepler archival photometry orbiting the K4-dwarf KIC-3239945. With a radius of (0.91+/- 0.02) {R}{{J}}, a low orbital eccentricity ({0.06}-0.04+0.10), and an equilibrium temperature of (131+/- 3) 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 coverage, we are able to uniquely and precisely measure the orbital period of this post snow-line planet (1071.2323 ± 0.0006d), paving the way for follow-up of this K = 11.8 mag target.

  4. Visual Effects in the High Performance Aircraft Cockpit

    DTIC Science & Technology

    1988-04-01

    Convergence: To be 10cm or less. Media and Fundi There should be no evidence of pathology which could impair visual performance either at the time of...that our prevention actions are not based only on a few spectacular, media interesting, accidents. 3. Visual related accidents/incidents As described...From Air Scoop DOCs TURN (Lt. Col. 3.D. Stevenson): There’s a trend developing which the flying safety folks and I have noted in recent mis- hap reports

  5. Neural Analog Information Processing

    NASA Astrophysics Data System (ADS)

    Hecht-Nielsen, Robert

    1982-07-01

    Neural Analog Information Processing (NAIP) is an effort to develop general purpose pattern classification architectures based upon biological information processing principles. This paper gives an overview of NAIP and its relationship to the previous work in neural modeling from which its fundamental principles are derived. It also presents a theorem concerning the stability of response of a slab (a two dimensional array of identical simple processing units) to time-invariant (spatial) patterns. An experiment (via computer emulation) demonstrating classification of a spatial pattern by a simple, but complete NAIP architecture is described. A concept for hardware implementation of NAIP architectures is briefly discussed.

  6. Analogical Processes in Learning

    DTIC Science & Technology

    1980-09-15

    CLASSICATMN OF ThIS PA5UrSfie Dule gIt.,.d ANALOGICAL PROCESSES IN LEARNING David E . Rumelhart & Donald A. Norman Program in Cognitive Science Center...for Human Information Processing University of California, San Diego La Jolla, California 92093 Copyright Q) 1980 David E . Rumelhart & Donald A. Norman...4) SEARS 7 E Ilamnp C5P Tota $.600 Aprovd.L. Figure 1. Stimuli for the two conditions of D’Andrade’s reasoning * experiment. The left panel shows the

  7. Antarctic Space Analog Program

    NASA Technical Reports Server (NTRS)

    Palinkas, Lawrence A; Gunderson, E. K. Eric; Johnson, Jeffrey C.; Holland, Albert W.

    1998-01-01

    The primary aim of this project was to examine group dynamics and individual performance in extreme, isolated environments and identify human factors requirements for long-duration space missions using data collected in an analog environment. Specifically, we wished to determine: 1) the characteristics of social relations in small groups of individuals living and working together in extreme, isolated environments, and 2) the environmental, social and psychological determinants of performance effectiveness in such groups. These two issues were examined in six interrelated studies using data collected in small, isolated research stations in Antarctica from 1963 to the present. Results from these six studies indicated that behavior and performance on long-duration space flights is likely to be seasonal or cyclical, situational, social, and salutogenic in nature. The project responded to two NASA program emphases for FY 1997 as described in the NRA: 1) the primary emphasis of the Behavior and Performance Program on determining long-term individual and group performance responses to space, identifying critical factors affecting those responses and understanding underlying mechanisms involved in behavior and performance, and developing and using ground-based models and analogs for studying space-related behavior and performance; and 2) the emphasis of the Data Analysis Program on extended data analysis. Results from the study were used to develop recommendations for the design and development of pre-flight crew training and in-flight psychological countermeasures for long-duration manned space missions.

  8. Toward "Constructing" the Concept of Statistical Power: An Optical Analogy.

    ERIC Educational Resources Information Center

    Rogers, Bruce G.

    This paper presents a visual analogy that may be used by instructors to teach the concept of statistical power in statistical courses. Statistical power is mathematically defined as the probability of rejecting a null hypothesis when that null is false, or, equivalently, the probability of detecting a relationship when it exists. The analogy…

  9. Of Water Troughs and the Sun: Developing Inquiry through Analogy

    ERIC Educational Resources Information Center

    Cowan, Kay W.; Cipriani, Sandra

    2009-01-01

    Visual intelligence is a key element in the thought processes of the most capable and creative among individuals, and this intelligence is closely related to analogical thinking, a learner's ability to make connections between prior knowledge and newly presented information. This article describes an approach to teaching scientific inquiry at…

  10. Mars inflatable greenhouse analog.

    PubMed

    Sadler, Philip D; Giacomelli, Gene A

    2002-01-01

    Light intensities on the Martian surface can possibly support a bioregenerative life support system (BLSS) utilizing natural sunlight for hydroponic crop production, if a suitable controlled environment can be provided. Inflatable clear membrane structures offer low mass, are more easily transported than a rigid structure, and are good candidates for providing a suitable controlled environment for crop production. Cable culture is one hydroponic growing system that can take advantage of the beneficial attributes of the inflatable structure. An analog of a Mars inflatable greenhouse can provide researchers data on issues such as crew time requirements for operation, productivity for BLSS, human factors, and much more at a reasonable cost. This is a description of one such design.

  11. Female analogies to perversion.

    PubMed

    Beier, K M

    2000-01-01

    Unlike the intrapsychic mechanism for self-esteem regulation in males as a basic component of perversion--extrapsychically (compensationally) culminating in an output of sexual impulses--a functional stabilization of the female self-concept seems more likely if conflict drives were to be focused on reproductional aspects and not on sexuality. It therefore seems more suitable to use a new expression in linguistic analogy to perversion: "reproversion." The case history gives an example of a clinical manifestation of "reproverse" symptom formation. The general survey describes the main points of view in regard to clinically oriented differentiation, i.e., intensity, ego-proximity in the personality structure, and one's own self-acceptance within "reproverse" symptom formation. Underlying personality disturbances are also discussed. The significance of reproversion is relevant to many different specialized medical fields. This is explained in conclusion, using the examples of denied pregnancy and infanticide at birth based on initial empirical results.

  12. Automated D/3 to Visio Analog Diagrams

    SciTech Connect

    Posey, Stephen B.

    2000-08-10

    ADVAD1 reads an ASCII file containing the D/3 DCS MDL input for analog points for a D/3 continuous database. It uses the information in the files to create a series of Visio files representing the structure of each analog chain, one drawing per Visio file. The actual drawing function is performed by Visio (requires Visio version 4.5+). The user can configure the program to select which fields in the database are shown on the diagram and how the information is to be presented. This gives a visual representation of the structure of the analog chains, showing selected fields in a consistent manner. Updating documentation can be done easily and the automated approach eliminates human error in the cadding process. The program can also create the drawings far faster than a human operator is capable, able to create approximately 270 typical diagrams in about 8 minutes on a Pentium II 400 MHz PC. The program allows for multiple option sets to be saved to provide different settings (i.e., different fields, different field presentations, and /or different diagram layouts) for various scenarios or facilities on one workstation. Option sets may be exported from the Windows registry to allow duplication of settings on another workstation.

  13. Mathematical problem solving by analogy.

    PubMed

    Novick, L R; Holyoak, K J

    1991-05-01

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

  14. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  15. Visual Impairment

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Visual Impairment KidsHealth > For Teens > Visual Impairment Print A ... with the brain, making vision impossible. What Is Visual Impairment? Many people have some type of visual ...

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

    PubMed

    Nachtigall, Werner

    2010-01-01

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

  17. Administrative simplification: adoption of a standard for a unique health plan identifier; addition to the National Provider Identifier requirements; and a change to the compliance date for the International Classification of Diseases, 10th Edition (ICD-10-CM and ICD-10-PCS) medical data code sets. Final rule.

    PubMed

    2012-09-05

    This final rule adopts the standard for a national unique health plan identifier (HPID) and establishes requirements for the implementation of the HPID. In addition, it adopts a data element that will serve as an other entity identifier (OEID), or an identifier for entities that are not health plans, health care providers, or individuals, but that need to be identified in standard transactions. This final rule also specifies the circumstances under which an organization covered health care provider must require certain noncovered individual health care providers who are prescribers to obtain and disclose a National Provider Identifier (NPI). Lastly, this final rule changes the compliance date for the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) for diagnosis coding, including the Official ICD-10-CM Guidelines for Coding and Reporting, and the International Classification of Diseases, 10th Revision, Procedure Coding System (ICD-10-PCS) for inpatient hospital procedure coding, including the Official ICD-10-PCS Guidelines for Coding and Reporting, from October 1, 2013 to October 1, 2014.

  18. Visual Perception versus Visual Function.

    ERIC Educational Resources Information Center

    Lieberman, Laurence M.

    1984-01-01

    Disfunctions are drawn between visual perception and visual function, and four optometrists respond with further analysis of the visual perception-visual function controversy and its implications for children with learning problems. (CL)

  19. Spaceflight Sensorimotor Analogs: Simulating Acute and Adaptive Effects

    NASA Technical Reports Server (NTRS)

    Taylor, Laura C.; Harm, Deborah L.; Kozlovskaya, Inessa; Reschke, Millard F.; Wood, Scott J.

    2009-01-01

    Adaptive changes in sensorimotor function during spaceflight are reflected by spatial disorientation, motion sickness, gaze destabilization and decrements in balance, locomotion and eye-hand coordination that occur during and following transitions between different gravitational states. The purpose of this study was to conduct a meta-synthesis of data from spaceflight analogs to evaluate their effectiveness in simulating adaptive changes in sensorimotor function. METHODS. The analogs under review were categorized as either acute analogs used to simulate performance decrements accompanied with transient changes, or adaptive analogs used to drive sensorimotor learning to altered sensory feedback. The effectiveness of each analog was evaluated in terms of mechanisms of action, magnitude and time course of observed deficits compared to spaceflight data, and the effects of amplitude and exposure duration. RESULTS. Parabolic flight has been used extensively to examine effects of acute variation in gravitational loads, ranging from hypergravity to microgravity. More recently, galvanic vestibular stimulation has been used to elicit acute postural, locomotor and gaze dysfunction by disrupting vestibular afferents. Patient populations, e.g., with bilateral vestibular loss or cerebellar dysfunction, have been proposed to model acute sensorimotor dysfunction. Early research sponsored by NASA involved living onboard rotating rooms, which appeared to approximate the time course of adaptation and post-exposure recovery observed in astronauts following spaceflight. Exposure to different bed-rest paradigms (6 deg head down, dry immersion) result in similar motor deficits to that observed following spaceflight. Shorter adaptive analogs have incorporated virtual reality environments, visual distortion paradigms, exposure to conflicting tilt-translation cues, and exposure to 3Gx centrifugation. As with spaceflight, there is considerable variability in responses to most of the analogs

  20. Natural analog studies: Licensing perspective

    SciTech Connect

    Bradbury, J.W.

    1995-09-01

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

  1. Conjecturing via Reconceived Classical Analogy

    ERIC Educational Resources Information Center

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

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

  2. Drawing Analogies in Environmental Education

    ERIC Educational Resources Information Center

    Affifi, Ramsey

    2014-01-01

    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…

  3. Cannabinoid properties of methylfluorophosphonate analogs.

    PubMed

    Martin, B R; Beletskaya, I; Patrick, G; Jefferson, R; Winckler, R; Deutsch, D G; Di Marzo, V; Dasse, O; Mahadevan, A; Razdan, R K

    2000-09-01

    Methylarachidonylfluorophosphonate (MAFP) and related analogs have been shown to inhibit fatty acid amidohydrolase activity (FAAH), the enzyme responsible for hydrolysis of the endogenous cannabinoid ligand anandamide. To fully characterize this class of compounds, methylfluorophosphonate compounds with saturated alkyl chains ranging from C8 to C20 along with C20 unsaturated derivatives were synthesized and evaluated for their ability to interact with the CB1 receptor, inhibit FAAH, and produce in vivo pharmacological effects. These analogs demonstrated widely varying affinities for the CB1 receptor. Of the saturated compounds, C8:0 was incapable of displacing [(3)H]CP 55,940 binding, whereas C12:0 exhibited high affinity (2.5 nM). The C20:0 saturated analog had low affinity (900 nM), but the introduction of unsaturation into the C20 analogs restored receptor affinity. However, none of the analogs were capable of fully displacing [(3)H]CP 55,940 binding. On the other hand, all compounds were able to completely inhibit FAAH enzyme activity, with the C20:0 analog being the least potent. The most potent FAAH inhibitor was the short-chained saturated C12:0, whereas the other analogs were 15- to 30-fold less potent. In vivo, the C8:0 and C12:0 analogs were highly potent and fully efficacious in producing tetrahydrocannabinol (THC)-like effects, whereas the other analogs were either inactive or acted as partial agonists. None was capable of attenuating the agonist effects of THC. Conversely, the C20:0 analog potentiated the effects of anandamide but not those of 2-arachidonoyl-glycerol and THC. The high in vivo potency of the novel short-chain saturated MAFP derivatives (C8:0 and C12:0) underscores the complexity of manipulating the endogenous cannabinoid system.

  4. Analogical reasoning in amazons.

    PubMed

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

    2015-11-01

    Two juvenile orange-winged amazons (Amazona amazonica) were initially trained to match visual stimuli by color, shape, and number of items, but not by size. After learning these three identity matching-to-sample tasks, the parrots transferred discriminative responding to new stimuli from the same categories that had been used in training (other colors, shapes, and numbers of items) as well as to stimuli from a different category (stimuli varying in size). In the critical testing phase, both parrots exhibited reliable relational matching-to-sample (RMTS) behavior, suggesting that they perceived and compared the relationship between objects in the sample stimulus pair to the relationship between objects in the comparison stimulus pairs, even though no physical matches were possible between items in the sample and comparison pairs. The parrots spontaneously exhibited this higher-order relational responding without having ever before been trained on RMTS tasks, therefore joining apes and crows in displaying this abstract cognitive behavior.

  5. Distributed Episodic and Analogical Reasoning (DEAR)

    DTIC Science & Technology

    2010-04-01

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

  6. Solving a problem by analogy

    NASA Astrophysics Data System (ADS)

    Easton, Don

    1999-03-01

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

  7. Flight Analogs (Bed Rest Research)

    NASA Video Gallery

    Flight Analogs / Bed Rest Research Projects provide NASA with a ground based research platform to complement space research. By mimicking the conditions of weightlessness in the human body here on ...

  8. Analog actuator-piston memory

    NASA Technical Reports Server (NTRS)

    Sable, B. A.

    1980-01-01

    Simple analog control system of digitally controlled acuator uses 'stopped' position of actuator as 'memory' and potentiometer as sensing element during power failure to reload drive circuit to value equal to its last position preceding power loss.

  9. Analog device simulates physiological waveforms

    NASA Technical Reports Server (NTRS)

    Hickman, D. M.

    1964-01-01

    An analog physiological simulator generates representative waveforms for a wide range of physiological conditions. Direct comparison of these waveforms with those from telemetric inputs permits quick detection of signal parameter degradation.

  10. Introduction to Analog Field Testing

    NASA Video Gallery

    NASA tests systems and operational concepts in analog environments, which include locations underwater, in the arctic, on terrestrial impact craters, in the desert, and on the International Space S...

  11. The Robustness of Acoustic Analogies

    NASA Technical Reports Server (NTRS)

    Freund, J. B.; Lele, S. K.; Wei, M.

    2004-01-01

    Acoustic analogies for the prediction of flow noise are exact rearrangements of the flow equations N(right arrow q) = 0 into a nominal sound source S(right arrow q) and sound propagation operator L such that L(right arrow q) = S(right arrow q). In practice, the sound source is typically modeled and the propagation operator inverted to make predictions. Since the rearrangement is exact, any sufficiently accurate model of the source will yield the correct sound, so other factors must determine the merits of any particular formulation. Using data from a two-dimensional mixing layer direct numerical simulation (DNS), we evaluate the robustness of two analogy formulations to different errors intentionally introduced into the source. The motivation is that since S can not be perfectly modeled, analogies that are less sensitive to errors in S are preferable. Our assessment is made within the framework of Goldstein's generalized acoustic analogy, in which different choices of a base flow used in constructing L give different sources S and thus different analogies. A uniform base flow yields a Lighthill-like analogy, which we evaluate against a formulation in which the base flow is the actual mean flow of the DNS. The more complex mean flow formulation is found to be significantly more robust to errors in the energetic turbulent fluctuations, but its advantage is less pronounced when errors are made in the smaller scales.

  12. Mapping health assessment questionnaire disability index (HAQ-DI) score, pain visual analog scale (VAS), and disease activity score in 28 joints (DAS28) onto the EuroQol-5D (EQ-5D) utility score with the KORean Observational study Network for Arthritis (KORONA) registry data.

    PubMed

    Kim, Hye-Lin; Kim, Dam; Jang, Eun Jin; Lee, Min-Young; Song, Hyun Jin; Park, Sun-Young; Cho, Soo-Kyung; Sung, Yoon-Kyoung; Choi, Chan-Bum; Won, Soyoung; Bang, So-Young; Cha, Hoon-Suk; Choe, Jung-Yoon; Chung, Won Tae; Hong, Seung-Jae; Jun, Jae-Bum; Kim, Jinseok; Kim, Seong-Kyu; Kim, Tae-Hwan; Kim, Tae-Jong; Koh, Eunmi; Lee, Hwajeong; Lee, Hye-Soon; Lee, Jisoo; Lee, Shin-Seok; Lee, Sung Won; Park, Sung-Hoon; Shim, Seung-Cheol; Yoo, Dae-Hyun; Yoon, Bo Young; Bae, Sang-Cheol; Lee, Eui-Kyung

    2016-04-01

    The aim of this study was to estimate the mapping model for EuroQol-5D (EQ-5D) utility values using the health assessment questionnaire disability index (HAQ-DI), pain visual analog scale (VAS), and disease activity score in 28 joints (DAS28) in a large, nationwide cohort of rheumatoid arthritis (RA) patients in Korea. The KORean Observational study Network for Arthritis (KORONA) registry data on 3557 patients with RA were used. Data were randomly divided into a modeling set (80 % of the data) and a validation set (20 % of the data). The ordinary least squares (OLS), Tobit, and two-part model methods were employed to construct a model to map to the EQ-5D index. Using a combination of HAQ-DI, pain VAS, and DAS28, four model versions were examined. To evaluate the predictive accuracy of the models, the root-mean-square error (RMSE) and mean absolute error (MAE) were calculated using the validation dataset. A model that included HAQ-DI, pain VAS, and DAS28 produced the highest adjusted R (2) as well as the lowest Akaike information criterion, RMSE, and MAE, regardless of the statistical methods used in modeling set. The mapping equation of the OLS method is given as EQ-5D = 0.95-0.21 × HAQ-DI-0.24 × pain VAS/100-0.01 × DAS28 (adjusted R (2) = 57.6 %, RMSE = 0.1654 and MAE = 0.1222). Also in the validation set, the RMSE and MAE were shown to be the smallest. The model with HAQ-DI, pain VAS, and DAS28 showed the best performance, and this mapping model enabled the estimation of an EQ-5D value for RA patients in whom utility values have not been measured.

  13. Analogous intermediate shape coding in vision and touch

    PubMed Central

    Yau, Jeffrey M.; Pasupathy, Anitha; Fitzgerald, Paul J.; Hsiao, Steven S.; Connor, Charles E.

    2009-01-01

    We recognize, understand, and interact with objects through both vision and touch. Conceivably, these two sensory systems encode object shape in similar ways, which could facilitate cross-modal communication. To test this idea, we studied single neurons in macaque monkey intermediate visual (area V4) and somatosensory (area SII) cortex, using matched shape stimuli. We found similar patterns of shape sensitivity characterized by tuning for curvature direction. These parallel tuning patterns imply analogous shape coding mechanisms in intermediate visual and somatosensory cortex. PMID:19805320

  14. Analog approach to mixed analog-digital circuit simulation

    NASA Astrophysics Data System (ADS)

    Ogrodzki, Jan

    2013-10-01

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

  15. Visual agnosia.

    PubMed

    Álvarez, R; Masjuan, J

    2016-03-01

    Visual agnosia is defined as an impairment of object recognition, in the absence of visual acuity or cognitive dysfunction that would explain this impairment. This condition is caused by lesions in the visual association cortex, sparing primary visual cortex. There are 2 main pathways that process visual information: the ventral stream, tasked with object recognition, and the dorsal stream, in charge of locating objects in space. Visual agnosia can therefore be divided into 2 major groups depending on which of the two streams is damaged. The aim of this article is to conduct a narrative review of the various visual agnosia syndromes, including recent developments in a number of these syndromes.

  16. All-optical analog comparator.

    PubMed

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

    2016-08-23

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

  17. All-optical analog comparator

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  18. All-optical analog comparator

    PubMed Central

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

    2016-01-01

    An analog comparator is one of the core units in all-optical analog-to-digital conversion (AO-ADC) systems, which digitizes different amplitude levels into two levels of logical ‘1’ or ‘0’ by comparing with a defined decision threshold. Although various outstanding photonic ADC approaches have been reported, almost all of them necessitate an electrical comparator to carry out this binarization. The use of an electrical comparator is in contradiction to the aim of developing all-optical devices. In this work, we propose a new concept of an all-optical analog comparator and numerically demonstrate an implementation based on a quarter-wavelength-shifted distributed feedback laser diode (QWS DFB-LD) with multiple quantum well (MQW) structures. Our results show that the all-optical comparator is very well suited for true AO-ADCs, enabling the whole digital conversion from an analog optical signal (continuous-time signal or discrete pulse signal) to a binary representation totally in the optical domain. In particular, this all-optical analog comparator possesses a low threshold power (several mW), high extinction ratio (up to 40 dB), fast operation rate (of the order of tens of Gb/s) and a step-like transfer function. PMID:27550874

  19. Teaching Scientific Analogies: A Proposed Model.

    ERIC Educational Resources Information Center

    Zeitoun, Hassan Hussein

    Cognitive psychologists have recently alluded to the role analogies might play in learning unfamiliar topics. However, since the use of analogies in science teaching has not been adequately addressed, analogies mean different things to different people. Therefore, a model for the teaching of scientific analogies is proposed. A theoretical…

  20. Analogies in Science and Science Teaching

    ERIC Educational Resources Information Center

    Brown, Simon; Salter, Susan

    2010-01-01

    Analogies are often used in science, but students may not appreciate their significance, and so the analogies can be misunderstood or discounted. For this reason, educationalists often express concern about the use of analogies in teaching. Given the important place of analogies in the discourse of science, it is necessary that students are…

  1. Natural analogs for Yucca Mountain

    SciTech Connect

    Murphy, W.M.

    1995-11-01

    High-level radioactive waste in the US, spent fuels from commercial reactors and nuclear materials generated by defense activities, will remain potentially hazardous for thousands of years. Demonstrable long-term stability of certain geologic and geochemical systems motivates and sustains the concept that high-level waste can be safely isolated in geologic repositories for requisite periods of time. Each geologic repository is unique in its properties and performance with reguard to isolation of nuclear wastes. Studies of processes analogous to waste-form alteration and radioelement transport in environments analogous to Yucca Mountain are being conducted at two sites, described in this article to illustrate uses of natural analog data: the Nopal I uranium deposit in the Sierra Pena Blanca, Mexico, and the Akrotiri archaeological site on the island of Santorini, Greece.

  2. Analog circuits for relaxation networks.

    PubMed

    Card, H

    1993-12-01

    Selected examples are presented of recent advances, primarily from the U.S. and Canada, in analog circuits for relaxation networks. Relaxation networks having feedback connections exhibit potentially greater computational power per neuron than feedforward networks. They are also more poorly understood especially with respect to learning algorithms. Examples are described of analog circuits for (i) supervised learning in deterministic Boltzmann machines, (ii) unsupervised competitive learning and feature maps and (iii) networks with resistive grids for vision and audition tasks. We also discuss recent progress on in-circuit learning and synaptic weight storage mechanisms.

  3. Terrestrial analogs for space exploration habitation systems

    NASA Technical Reports Server (NTRS)

    Campbell, Paul D.; Brown, Jeri W.

    1992-01-01

    The Space Exploration Initiative (SEI) can use early earth-based analogs to simulate many aspects of space flight missions and system operation. These analogs can thus provide information supporting future missions to the moon and to Mars. A study was performed to investigate the potential of terrestrial analogs in simulating human space exploration missions. The study resulted in preliminary requirements and concepts for analog habitation systems, and further study in this area is necessary for SEI terrestrial analog development.

  4. Analogies and "Modeling Analogies" in Teaching: Some Examples in Basic Electricity.

    ERIC Educational Resources Information Center

    Dupin, J. J.; Johsua, S.

    1989-01-01

    Investigates the effect of modeling analogy on learning of the concepts of electricity in grade 6, 8, and 10. Describes 2 analogies (train analogy and thermal analogy) with diagrams and examples. Discusses the accessibility, transferability, and difficulty of each analogy. Reports treatment effect and some further implications. (YP)

  5. Understanding & Teaching Genetics Using Analogies

    ERIC Educational Resources Information Center

    Woody, Scott; Himelblau, Ed

    2013-01-01

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

  6. Geometrical Analogies in Mathematics Lessons

    ERIC Educational Resources Information Center

    Eid, Wolfram

    2007-01-01

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

  7. Mathematical Analogy and Metaphorical Insight

    ERIC Educational Resources Information Center

    Zwicky, Jan

    2010-01-01

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

  8. Analogy between Thermodynamics and Mechanics.

    ERIC Educational Resources Information Center

    Peterson, Mark A.

    1979-01-01

    Establishes and illustrates a formal analogy between the motion of a particle and the "motion" of the equilibrium state of a homogeneous system in a quasistatic process. The purpose is to show that there is a much larger set of natural coordinate transformations in thermodynamics. (GA)

  9. Analog Input Data Acquisition Software

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2009-01-01

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

  10. Bayesian Analogy with Relational Transformations

    ERIC Educational Resources Information Center

    Lu, Hongjing; Chen, Dawn; Holyoak, Keith J.

    2012-01-01

    How can humans acquire relational representations that enable analogical inference and other forms of high-level reasoning? Using comparative relations as a model domain, we explore the possibility that bottom-up learning mechanisms applied to objects coded as feature vectors can yield representations of relations sufficient to solve analogy…

  11. Analogy of the Cell Project

    ERIC Educational Resources Information Center

    Science Scope, 2005

    2005-01-01

    In this project, students compare the makeup of a cell to an everyday working unit or system. They create a three-dimensional object that represents their analogy. For example, students could create a car motor or manufacturing plant. (Of course, this is totally hand-created by them, so it can be a homemade re-creation of a system, not an actual…

  12. Electrical analog to projectile motion

    NASA Astrophysics Data System (ADS)

    Vondracek, Mark

    1998-04-01

    This article describes an electrical analog to traditional projectile problems given in high school and introductory college classes. It also discusses the importance of stressing the understanding of physical laws and principles to students, and that the physics behind a problem is more important than being able to memorize and use various equations.

  13. International Alligator Rivers Analog Project

    SciTech Connect

    Bichard, G.F.

    1988-01-01

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

  14. Analog Simulation of a Laser.

    ERIC Educational Resources Information Center

    Kessler, Gary

    1982-01-01

    Presents an analog simulation of laser properties (finding time evolution of the intensity of a ruby laser pulse) which serves as the basis of a three-four hour laboratory experiment. Includes programs for solution to rate equations of a three-level laser and production of a giant pulse in a ruby laser. (Author/SK)

  15. Schema Training in Analogical Reasoning.

    ERIC Educational Resources Information Center

    Robins, Shani; Mayer, Richard E.

    1993-01-01

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

  16. Visual signatures in video visualization.

    PubMed

    Chen, Min; Botchen, Ralf P; Hashim, Rudy R; Weiskopf, Daniel; Ertl, Thomas; Thornton, Ian M

    2006-01-01

    Video visualization is a computation process that extracts meaningful information from original video data sets and conveys the extracted information to users in appropriate visual representations. This paper presents a broad treatment of the subject, following a typical research pipeline involving concept formulation, system development, a path-finding user study, and a field trial with real application data. In particular, we have conducted a fundamental study on the visualization of motion events in videos. We have, for the first time, deployed flow visualization techniques in video visualization. We have compared the effectiveness of different abstract visual representations of videos. We have conducted a user study to examine whether users are able to learn to recognize visual signatures of motions, and to assist in the evaluation of different visualization techniques. We have applied our understanding and the developed techniques to a set of application video clips. Our study has demonstrated that video visualization is both technically feasible and cost-effective. It has provided the first set of evidence confirming that ordinary users can be accustomed to the visual features depicted in video visualizations, and can learn to recognize visual signatures of a variety of motion events.

  17. Visual Imagery without Visual Perception?

    ERIC Educational Resources Information Center

    Bertolo, Helder

    2005-01-01

    The question regarding visual imagery and visual perception remain an open issue. Many studies have tried to understand if the two processes share the same mechanisms or if they are independent, using different neural substrates. Most research has been directed towards the need of activation of primary visual areas during imagery. Here we review…

  18. Analog Video Authentication and Seal Verification Equipment Development

    SciTech Connect

    Gregory Lancaster

    2012-09-01

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

  19. Analog Nonvolatile Computer Memory Circuits

    NASA Technical Reports Server (NTRS)

    MacLeod, Todd

    2007-01-01

    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

  20. Battery hydrometer with analog output

    SciTech Connect

    Patis, B.L.

    1982-09-21

    There is disclosed a battery hydrometer for providing an analog electrical signal having a magnitude related to the specific gravity of a battery electrolyte. The hydrometer includes a source of radiation for providing a detectable beam of radiation and a piston member arranged to be submerged within the electrolyte and to intercept and modulate the beam of radiation in response to the specific gravity of the electrolyte. The piston member is suspended within the electrolyte by a spring which exerts a compressive force upon the piston member against which the electrolyte must act. The hydrometer further includes a radiation detector aligned with the radiation source for providing an analog electrical signal having a magnitude responsive to the modulated beam of radiation.

  1. Synaptic dynamics in analog VLSI.

    PubMed

    Bartolozzi, Chiara; Indiveri, Giacomo

    2007-10-01

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

  2. Classical Analog to Entanglement Reversibility

    NASA Astrophysics Data System (ADS)

    Chitambar, Eric; Fortescue, Ben; Hsieh, Min-Hsiu

    2015-08-01

    In this Letter we study the problem of secrecy reversibility. This asks when two honest parties can distill secret bits from some tripartite distribution pX Y Z and transform secret bits back into pX Y Z at equal rates using local operation and public communication. This is the classical analog to the well-studied problem of reversibly concentrating and diluting entanglement in a quantum state. We identify the structure of distributions possessing reversible secrecy when one of the honest parties holds a binary distribution, and it is possible that all reversible distributions have this form. These distributions are more general than what is obtained by simply constructing a classical analog to the family of quantum states known to have reversible entanglement. An indispensable tool used in our analysis is a conditional form of the Gács-Körner common information.

  3. DOTA-Derivatives of Octreotide Dicarba-Analogs with High Affinity for Somatostatin sst2,5 Receptors.

    PubMed

    Pratesi, Alessandro; Ginanneschi, Mauro; Lumini, Marco; Papini, Anna M; Novellino, Ettore; Brancaccio, Diego; Carotenuto, Alfonso

    2017-01-01

    In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumors and their metastases. In fact, peptide ligands of somatostatin receptors (sst's) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogs, which show interesting binding profiles at sst's. In this context, it was mandatory to explore the possibility that our analogs could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogs of octreotide. Interestingly, two conjugated analogs exhibited nanomolar affinities on sst2 and sst5 somatostatin receptor subtypes.

  4. Superconducting Analog to Digital Converters

    DTIC Science & Technology

    1991-09-01

    superconductivity, Josephson junctions, and superconducting quantum interference devices ( SQUIDs ) are briefly described. Various techniques to perform analog-to...deployment in the 1990s may require a dynamic range in excess of 90 dB (15- bit precision) [3]. However, at the present time, A/D conversion with 16-bit...Interference Devices ( SQUIDs ). JOSEPHSON EFFECTS AND JUNCTIONS Consider a very thin, non-superconducting region separating two superconductors. In 1962

  5. Stereoselective Syntheses of Soman Analog

    DTIC Science & Technology

    1993-04-28

    AD-A283 855 AD_ _ _ _ CONTRACT NO: DAMDl7-88-C-8021 0 / TITLE: STEREOSELECTIVE SYNTHESES OF SOMAN ANALOG SUBTITLE: Synthesis of Pentacoordinate...SUPPLEMENTARY NOTES SUBTITLE: Synthesis of Pentacoordinate Phosphorus Compounds, "Bait and Switch" Compounds, and Soman Simulants as Hapten. for Production of...simulant. We reporit a detailed study on the synthesis , isolation and characterization of the four pure enantiomners; of [(S or R)-4 -amino-2,2-diniethyl-2

  6. Health as an analogical concept.

    PubMed

    Mordacci, R

    1995-10-01

    This article examines the normative structure of the concept of health and tries to suggest an account of it in a phenomenological-hermeneutic framework. It is argued that the concept of health has a logical priority to illness, though the latter has an experiential priority. The fundamental feature of the concept of health as discussed in the literature is initially recognized in the notion of 'norm', in both the bio-statistical and normative-ideal sense. An analysis of this body of literature reveals some weaknesses in bio-statistical definitions of health as well as in those normative ones which endorse a value-relativity thesis. An approach based on the analogical structure of language is then advanced. In this framework, the notion of biological normativeness proposed by G. Canguilhem is connected with an analysis of the language of health through etymologies. It is argued that health can be characterized as an analogy of 'plenitude', which is the common ideal reference of the various health-concepts. The analogical structuring of language allows the recognition of different levels of meaning, and therefore of different kinds of normativeness (biological, mental, social, moral). Some hints of a theory of health deriving from this framework are then given.

  7. Simple Electronic Analog of a Josephson Junction.

    ERIC Educational Resources Information Center

    Henry, R. W.; And Others

    1981-01-01

    Demonstrates that an electronic Josephson junction analog constructed from three integrated circuits plus an external reference oscillator can exhibit many of the circuit phenomena of a real Josephson junction. Includes computer and other applications of the analog. (Author/SK)

  8. Basic Electricity--a Novel Analogy.

    ERIC Educational Resources Information Center

    Grant, Richard

    1996-01-01

    Uses the analogy of water flow to introduce concepts in basic electricity. Presents a demonstration that uses this analogy to help students grasp the relationship between current, voltage, and resistance. (JRH)

  9. Third order digital-to-analog converter

    NASA Technical Reports Server (NTRS)

    Dotson, W. P.

    1972-01-01

    System, consisting of sample and hold digital-to-analog converter, clock circuit, sample delay circuit, initial condition circuit and interpolator circuit, improves accuracy of reconstructed analog signal without increasing sample rates.

  10. The Structure of Analogical Models in Science.

    DTIC Science & Technology

    1980-07-01

    analogies cannot. 8. A Freudian defense might claim that the theory merely reflects the illogic of the unconscious. But a theory about an unclarified...explanatory-predictive analogy is contrasted with literary expressive metaphor. Finally, within science, good 4 explanatory analogy is contrasted with...an initial comparison. To illustrate the points, analogies of historical importance are analyzed. Although the focus is on theory , some empirical

  11. Hegel, Analogy, and Extraterrestrial Life

    NASA Astrophysics Data System (ADS)

    Ross, Joseph T.

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

  12. Analogical Reasoning: A Review of the Literature.

    ERIC Educational Resources Information Center

    Dawis, Rene V.; Siojo, Luis T.

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

  13. Reasoning by Analogy in Constructing Mathematical Ideas.

    ERIC Educational Resources Information Center

    English, Lyn D.

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

  14. The Micro-Category Account of Analogy

    ERIC Educational Resources Information Center

    Green, Adam E.; Fugelsang, Jonathan A.; Kraemer, David J. M.; Dunbar, Kevin N.

    2008-01-01

    Here, we investigate how activation of mental representations of categories during analogical reasoning influences subsequent cognitive processing. Specifically, we present and test the central predictions of the "Micro-Category" account of analogy. This account emphasizes the role of categories in aligning terms for analogical mapping. In a…

  15. Long-term assessment of prostaglandin analogs and timolol fixed combinations vs prostaglandin analogs monotherapy

    PubMed Central

    Liu, Ai-Wei; Gan, Lin-Yang; Yao, Xiang; Zhou, Jian

    2016-01-01

    AIM To draw a Meta-analysis over the comparison of the intraocular pressure (IOP)-lowering efficacy and safety between the commonly used fixed-combinations of prostaglandin analogs and 0.5% timolol with prostaglandin analogs (PGAs) monotherapy. METHODS After searching the published reports from MEDLINE, EMBASE, the Cochrane Library, all randomized controlled clinical trials (RCTs) comparing the fixed combination of PGAs/timolol therapy (FCs) and PGAs monotherapy with treatment duration at least 6mo were included. The efficacy outcomes were mean diurnal IOP, percentage of participants whose IOP were lower than 18 mm Hg, incidence of visual field change, while the safety outcomes included corneal side effects, hyperemia and eye irritation. The analysis was carried out in RevMan version 5.3 software. RESULTS After six-month medical intervention, the mean diurnal IOP of FCs was lower than PGAs (MD -1.14, 95% CI -1.82 to -0.46, P=0.001); the percentage of target IOP achieving between FCs and PGAs showed no significant difference (RR 1.18, 95% CI 0.97 to 1.43, P=0.10). No statistically significant differences of the incidence of hyperemia (RR 0.67, 95% CI 0.45 to 1.01, P=0.06) and eye irritation (RR 1.20, 95% CI 0.95 to 1.51, P=0.12) between the FCs and PGAs monotherapy were detected. Only one research involved in corneal events, result of this trial revealed no difference between two intervention groups regarding corneal effects (central endothelial cell density, MD -0.20, 95% CI -0.72 to 0.32, P=0.45; central corneal thickness, MD -0.01, 95% CI -0.02 to 0.00, P=0.23). The evaluation of visual field change was not performed due to the limited duration of the trials included in this Meta-analysis. CONCLUSION The long-term efficacy of the FCs overweighed the PGAs monotherapy in lowering IOP, but in the incidence of hyperemia and eye irritation syndromes, the differences are not statically significant. More RCTs with detailed and authentic data over the assessments of

  16. Classical analog of quantum phase

    SciTech Connect

    Ord, G.N.

    1992-07-01

    A modified version of the Feynman relativistic chessboard model (FCM) is investigated in which the paths involved are spirals in the space-time. Portions of the paths in which the particle`s proper time is reversed are interpreted in terms of antiparticles. With this intepretation the particle-antiparticle field produced by such trajectories provides a classical analog of the phase associated with particle paths in the unmodified FCM. It is shwon that in the nonrelativistic limit the resulting kernel is the correct Dirac propagator and that particle-antiparticle symmetry is in this case responsible for quantum interference. 7 refs., 3 figs.

  17. Mathematical Visualization

    ERIC Educational Resources Information Center

    Rogness, Jonathan

    2011-01-01

    Advances in computer graphics have provided mathematicians with the ability to create stunning visualizations, both to gain insight and to help demonstrate the beauty of mathematics to others. As educators these tools can be particularly important as we search for ways to work with students raised with constant visual stimulation, from video games…

  18. Visual Knowledge.

    ERIC Educational Resources Information Center

    Chipman, Susan F.

    Visual knowledge is an enormously important part of our total knowledge. The psychological study of learning and knowledge has focused almost exclusively on verbal materials. Today, the advance of technology is making the use of visual communication increasingly feasible and popular. However, this enthusiasm involves the illusion that visual…

  19. Visual Theorems.

    ERIC Educational Resources Information Center

    Davis, Philip J.

    1993-01-01

    Argues for a mathematics education that interprets the word "theorem" in a sense that is wide enough to include the visual aspects of mathematical intuition and reasoning. Defines the term "visual theorems" and illustrates the concept using the Marigold of Theodorus. (Author/MDH)

  20. Visual Thinking.

    ERIC Educational Resources Information Center

    Arnheim, Rudolf

    Based on the more general principle that all thinking (including reasoning) is basically perceptual in nature, the author proposes that visual perception is not a passive recording of stimulus material but an active concern of the mind. He delineates the task of visually distinguishing changes in size, shape, and position and points out the…

  1. Prostacyclin analogs inhibit fibroblast migration.

    PubMed

    Kohyama, Tadashi; Liu, Xiangde; Kim, Hui Jung; Kobayashi, Tetsu; Ertl, Ronald F; Wen, Fu-Qiang; Takizawa, Hajime; Rennard, Stephen I

    2002-08-01

    The controlled accumulation of fibroblasts to sites of inflammation is crucial to effective tissue repair after injury. Either inadequate or excessive accumulation of fibroblasts could result in abnormal tissue function. Prostacyclin (PGI(2)) is a potent mediator in the coagulation and inflammatory processes. The aim of this study was to investigate the effect of PGI(2) on chemotaxis of human fetal lung fibroblasts (HFL-1). Using the blind well chamber technique, we found that the PGI(2) analog carbaprostacyclin (10(-6) M) inhibited HFL-1 chemotaxis to human plasma fibronectin (20 microg/ml) 58.0 +/- 13.2% (P < 0.05) and to platelet-derived growth factor (PDGF)-BB (10 ng/ml) 48.7 +/- 4.6% (P < 0.05). Checkerboard analysis demonstrated that carbaprostacyclin inhibits both directed and undirected migration. The inhibitory effect of the carbaprostacyclin was concentration dependent and blocked by the cAMP-dependent protein kinase (PKA) inhibitor KT-5720, suggesting that a cAMP-PKA pathway may be involved in the process. Two other PGI(2) analogs, ciprostene and dehydro-15-cyclohexyl carbaprostacyclin (both 10(-6) M), significantly inhibited fibroblast migration to fibronectin. In summary, PGI(2) appears to inhibit fibroblast chemotaxis to fibronectin and PDGF-BB. Such an effect may contribute to the regulation of fibroblasts in wound healing and could contribute to the pathogenesis of diseases characterized by abnormal tissue repair remodeling.

  2. A precondition prover for analogy.

    PubMed

    Bledsoe, W W

    1995-01-01

    We describe here a prover PC (precondition) that normally acts as an ordinary theorem prover, but which returns a 'precondition' when it is unable to prove the given formula. If F is the formula attempted to be proved and PC returns the precondition Q, then (Q-->F) is a theorem (that PC can prove). This prover, PC, uses a proof-plan. In its simplest mode, when there is no proof-plan, it acts like ordinary abduction. We show here how this method can be used to derive certain proofs by analogy. To do this, it uses a proof-plan from a given guiding proof to help construct the proof of a similar theorem, by 'debugging' (automatically) that proof-plan. We show here the analogy proofs of a few simple example theorems and one hard pair, Ex4 and Ex4L. The given proof-plan for Ex4 is used by the system to prove automatically Ex4; and that same proof-plan is then used to prove Ex4L, during which the proof-plan is 'debugged' (automatically). These two examples are similar to two other, more difficult, theorems from the theory of resolution, namely GCR (the ground completeness of resolution) and GCLR (the ground completeness of lock resolution). GCR and GCLR have also been handled, in essence, by this system but not completed in all their details.

  3. A Visual Literacy Approach to Developmental and Remedial Reading.

    ERIC Educational Resources Information Center

    Barley, Steven D.

    Photography, films, and other visual materials offer a different approach to teaching reading. For example, photographs may be arranged in sequences analogous to the ways words form sentences and sentences for stories. If, as is possible, children respond first to pictures and later to words, training they receive in visual literacy may help them…

  4. Visual cognition

    PubMed Central

    Cavanagh, Patrick

    2011-01-01

    Visual cognition, high-level vision, mid-level vision and top-down processing all refer to decision-based scene analyses that combine prior knowledge with retinal input to generate representations. The label “visual cognition” is little used at present, but research and experiments on mid- and high-level, inference-based vision have flourished, becoming in the 21st century a significant, if often understated part, of current vision research. How does visual cognition work? What are its moving parts? This paper reviews the origins and architecture of visual cognition and briefly describes some work in the areas of routines, attention, surfaces, objects, and events (motion, causality, and agency). Most vision scientists avoid being too explicit when presenting concepts about visual cognition, having learned that explicit models invite easy criticism. What we see in the literature is ample evidence for visual cognition, but few or only cautious attempts to detail how it might work. This is the great unfinished business of vision research: at some point we will be done with characterizing how the visual system measures the world and we will have to return to the question of how vision constructs models of objects, surfaces, scenes, and events. PMID:21329719

  5. [Visual Texture Agnosia in Humans].

    PubMed

    Suzuki, Kyoko

    2015-06-01

    Visual object recognition requires the processing of both geometric and surface properties. Patients with occipital lesions may have visual agnosia, which is impairment in the recognition and identification of visually presented objects primarily through their geometric features. An analogous condition involving the failure to recognize an object by its texture may exist, which can be called visual texture agnosia. Here we present two cases with visual texture agnosia. Case 1 had left homonymous hemianopia and right upper quadrantanopia, along with achromatopsia, prosopagnosia, and texture agnosia, because of damage to his left ventromedial occipitotemporal cortex and right lateral occipito-temporo-parietal cortex due to multiple cerebral embolisms. Although he showed difficulty matching and naming textures of real materials, he could readily name visually presented objects by their contours. Case 2 had right lower quadrantanopia, along with impairment in stereopsis and recognition of texture in 2D images, because of subcortical hemorrhage in the left occipitotemporal region. He failed to recognize shapes based on texture information, whereas shape recognition based on contours was well preserved. Our findings, along with those of three reported cases with texture agnosia, indicate that there are separate channels for processing texture, color, and geometric features, and that the regions around the left collateral sulcus are crucial for texture processing.

  6. Adaptive Problem Solving by Analogy

    DTIC Science & Technology

    2013-07-01

    developed and their advantages were demonstrated in a series of simulations. In addition, some psychological experiments were conducted in order to...simulations.  In  addition,  some  psychological  experiments were conducted  in order  to verify  the predictions of  the model. Within  the  project, we...tries  to map with  its analog  in  the  terrorist  situation.  Thus,  the  question  about  the  deep  psychological  motivation  of  the

  7. Fault diagnosis of analog circuits

    NASA Astrophysics Data System (ADS)

    Bandler, J. W.; Salama, A. E.

    1985-08-01

    Theory and algorithms associated with four main categories of modern techniques used to locate faults in analog circuits are presented. These four general approaches are: the fault dictionary (FDA), the parameter identification (PIA), the fault verification (FVA), and the approximation (AA) approaches. The preliminaries and problems associated with the FDA, such as fault dictionary construction, the methods of optimum measurement selection, fault isolation criteria, and efficient methods of fault simulation, are discussed. The PIA techniques that utilize either linear or nonlinear systems of equations for identification of network elements are examined. Description of the FVA includes node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions, as well as combinatorial techniques, the failure-bound technique, and the network decomposition technique. In the AA, probabilistic methods and optimization-based methods are considered. In addition, the artificial intelligence technique and the different measures of testability are presented. A series of block diagrams is included.

  8. Synthesis and radiolabeling of a somatostatin analog for multimodal imaging

    NASA Astrophysics Data System (ADS)

    Edwards, W. Barry; Liang, Kexian; Xu, Baogang; Anderson, Carolyn J.; Achilefu, Samuel

    2006-02-01

    A new multimodal imaging agent for imaging the somatostatin receptor has been synthesized and evaluated in vitro and in vivo. A somatostatin analog, conjugated to both 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaceticacid (DOTA) and cypate (BS-296), was synthesized entirely on the solid phase (Fmoc) and purified by RP-HPLC. DOTA was added as a ligand for radiometals such as 64Cu or 177Lu for either radio-imaging or radiotherapy respectively. Cytate, a cypatesomatostatin analog conjugate, has previously demonstrated the ability to visualize somatostatin receptor rich tumor xenografts and natural organs by optical imaging techniques. BS-296 exhibited low nanomolar inhibitory capacity toward the binding of radiolabeled somatostatin analogs in cell membranes enriched in the somatostatin receptor, demonstrating the high affinity of this multimodal imaging peptide and indicating its potential as a molecular imaging agent. 64Cu, an isotope for diagnostic imaging and radiotherapy, was selected as the isotope for radiolabeling BS-296. BS-296 was radiolabeled with 64Cu in high specific activity (200 μCi/μg) in 90% radiochemical yield. Addition of 2,5-dihydroxybenzoic acid (gentisic acid) prevented radiolysis of the sample, allowing for study of the 64Cu -BS-296 the day following radiolabeling. Furthermore, inclusion of DMSO at a level of 20% was found not to interfere with radiolabeling yields and prevented the adherence of 64Cu -BS-296 to the walls of the reaction vessel.

  9. Priming analogical reasoning with false memories.

    PubMed

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

    2015-08-01

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

  10. AnalogExplorer2 – Stereochemistry sensitive graphical analysis of large analog series

    PubMed Central

    Hu, Ye; Zhang, Bijun; Vogt, Martin; Bajorath, Jürgen

    2015-01-01

    AnalogExplorer is a computational methodology for the extraction and organization of series of structural analogs from compound data sets and their graphical analysis. The method is suitable for the analysis of large analog series originating from lead optimization programs. Herein we report AnalogExplorer2 designed to explicitly take stereochemical information during graphical analysis into account and describe a freely available deposition of the original AnalogExplorer program, AnalogExplorer2, and exemplary compound sets to illustrate their use. PMID:26913194

  11. Visual Impairment

    MedlinePlus

    ... or head with a baseball or having an automobile or motorcycle accident. Some babies have congenital blindness , ... how well he or she sees at various distances. Visual field test. Ophthalmologists use this test to ...

  12. Design and Analysis of Reconfigurable Analog System

    DTIC Science & Technology

    2011-02-01

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

  13. Classical Analogs of a Diatomic Chain

    SciTech Connect

    Gutierrez, L.; Diaz-de-Anda, A.; Mendez-Sanchez, R. A.; Morales, A.; Flores, J.; Monsivais, G.

    2010-12-21

    Using one dimensional rods with different configurations classical analogs of quantum mechanical systems frequently used in solid state physics can be obtained. Among this analogs we have recently discussed locally periodic rods which lead to band spectra; the effect of a topological defect, and the Wannier Stark ladders. In this paper, we present an elastic analog of the diatomic chain and show how the acoustical and optical bands emerge, as well of the nature of the wave amplitudes.

  14. Visual cognition

    SciTech Connect

    Pinker, S.

    1985-01-01

    This book consists of essays covering issues in visual cognition presenting experimental techniques from cognitive psychology, methods of modeling cognitive processes on computers from artificial intelligence, and methods of studying brain organization from neuropsychology. Topics considered include: parts of recognition; visual routines; upward direction; mental rotation, and discrimination of left and right turns in maps; individual differences in mental imagery, computational analysis and the neurological basis of mental imagery: componental analysis.

  15. Weak vs Strong Acids and Bases: The Football Analogy

    NASA Astrophysics Data System (ADS)

    Silverstein, Todd P.

    2000-07-01

    An important topic in any introductory chemistry course is that of acids and bases. Students generally have no trouble learning the Brønsted-Lowry definition of an acid as a proton donor and a base as a proton acceptor. Problems often arise, however, when chemistry teachers attempt to explain the difference between weak and strong acids, and between weak and strong bases. For acids in aqueous solution, discussing complete in contrast to partial ionization works well for those with a strong grasp of the equilibrium concept, but for many students it does not seem to do the trick. Partial ionization may not evoke much in the mind of a "visual learner". Accordingly, I have developed a football analogy for acids and bases in which acids are compared to quarterbacks, whose job is to get rid of the ball (H+). A strong acid, like an excellent quarterback, delivers the ball effectively; a weak acid, like a poor quarterback, is often left holding the ball. Furthermore, bases may be likened to wide receivers, whose job is to catch and hold onto the ball (H+). A strong base, like an excellent wide receiver, holds onto the ball; a weak base, like a poor receiver, often drops the ball. The concept of throwing and catching a ball is easy to visualize and the analogy to acids and bases can help even students unfamiliar with the mores of the gridiron to comprehend the mores of aqueous protons.

  16. Robust hyperchaotic synchronization via analog transmission line

    NASA Astrophysics Data System (ADS)

    Sadoudi, S.; Tanougast, C.

    2016-02-01

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

  17. Properties of compressible elastica from relativistic analogy.

    PubMed

    Oshri, Oz; Diamant, Haim

    2016-01-21

    Kirchhoff's kinetic analogy relates the deformation of an incompressible elastic rod to the classical dynamics of rigid body rotation. We extend the analogy to compressible filaments and find that the extension is similar to the introduction of relativistic effects into the dynamical system. The extended analogy reveals a surprising symmetry in the deformations of compressible elastica. In addition, we use known results for the buckling of compressible elastica to derive the explicit solution for the motion of a relativistic nonlinear pendulum. We discuss cases where the extended Kirchhoff analogy may be useful for the study of other soft matter systems.

  18. Fermilab accelerator control system: Analog monitoring facilities

    SciTech Connect

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

    1987-10-01

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

  19. Real World: Analog Testing in Extreme Environments

    NASA Video Gallery

    See how NASA uses analog testing to simulate space exploration. Explore extreme environments like the Aquarius underwater laboratory in Key Largo, Florida. Find out how scientists use mathematical ...

  20. The picture superiority effect in categorization: visual or semantic?

    PubMed

    Job, R; Rumiati, R; Lotto, L

    1992-09-01

    Two experiments are reported whose aim was to replicate and generalize the results presented by Snodgrass and McCullough (1986) on the effect of visual similarity in the categorization process. For pictures, Snodgrass and McCullough's results were replicated because Ss took longer to discriminate elements from 2 categories when they were visually similar than when they were visually dissimilar. However, unlike Snodgrass and McCullough, an analogous increase was also observed for word stimuli. The pattern of results obtained here can be explained most parsimoniously with reference to the effect of semantic similarity, or semantic and visual relatedness, rather than to visual similarity alone.

  1. Digital and analog chemical evolution.

    PubMed

    Goodwin, Jay T; Mehta, Anil K; Lynn, David G

    2012-12-18

    Living matter is the most elaborate, elegant, and complex hierarchical material known and is consequently the natural target for an ever-expanding scientific and technological effort to unlock and deconvolute its marvelous forms and functions. Our current understanding suggests that biological materials are derived from a bottom-up process, a spontaneous emergence of molecular networks in the course of chemical evolution. Polymer cooperation, so beautifully manifested in the ribosome, appeared in these dynamic networks, and the special physicochemical properties of the nucleic and amino acid polymers made possible the critical threshold for the emergence of extant cellular life. These properties include the precise and geometrically discrete hydrogen bonding patterns that dominate the complementary interactions of nucleic acid base-pairing that guide replication and ensure replication fidelity. In contrast, complex and highly context-dependent sets of intra- and intermolecular interactions guide protein folding. These diverse interactions allow the more analog environmental chemical potential fluctuations to dictate conformational template-directed propagation. When these two different strategies converged in the remarkable synergistic ribonucleoprotein that is the ribosome, this resulting molecular digital-to-analog converter achieved the capacity for both persistent information storage and adaptive responses to an ever-changing environment. The ancestral chemical networks that preceded the Central Dogma of Earth's biology must reflect the dynamic chemical evolutionary landscapes that allowed for selection, propagation, and diversification and ultimately the demarcation and specialization of function that modern biopolymers manifest. Not only should modern biopolymers contain molecular fossils of this earlier age, but it should be possible to use this information to reinvent these dynamic functional networks. In this Account, we review the first dynamic network

  2. Visual Prosthesis

    PubMed Central

    Schiller, Peter H.; Tehovnik, Edward J.

    2009-01-01

    There are more than 40 million blind individuals in the world whose plight would be greatly ameliorated by creating a visual prosthetic. We begin by outlining the basic operational characteristics of the visual system as this knowledge is essential for producing a prosthetic device based on electrical stimulation through arrays of implanted electrodes. We then list a series of tenets that we believe need to be followed in this effort. Central among these is our belief that the initial research in this area, which is in its infancy, should first be carried out in animals. We suggest that implantation of area V1 holds high promise as the area is of a large volume and can therefore accommodate extensive electrode arrays. We then proceed to consider coding operations that can effectively convert visual images viewed by a camera to stimulate electrode arrays to yield visual impressions that can provide shape, motion and depth information. We advocate experimental work that mimics electrical stimulation effects non-invasively in sighted human subjects using a camera from which visual images are converted into displays on a monitor akin to those created by electrical stimulation. PMID:19065857

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

    PubMed

    Sezgin, Erdinc; Can, Fatma Betul; Schneider, Falk; Clausen, Mathias P; Galiani, Silvia; Stanly, Tess A; Waithe, Dominic; Colaco, Alexandria; Honigmann, Alf; Wüstner, Daniel; Platt, Frances; Eggeling, Christian

    2016-02-01

    Cholesterol (Chol) is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of Chol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently labeled Chol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction, and trafficking in cells; hence, it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase-separated giant unilamellar vesicles and giant plasma membrane vesicles; 2) cellular trafficking, specifically subcellular localization in Niemann-Pick type C disease cells; and 3) applicability in fluorescence correlation spectroscopy (FCS)-based and super-resolution stimulated emission depletion-FCS-based measurements of membrane diffusion dynamics. The analogs exhibited strong differences, with some indicating positive performance in the membrane-based experiments and others in the intracellular trafficking assay. However, none showed positive performance in all assays. Our results constitute a concise guide for the careful use of fluorescent Chol analogs in visualizing cellular Chol dynamics.

  4. A comparative study on fluorescent cholesterol analogs as versatile cellular reporters[S

    PubMed Central

    Sezgin, Erdinc; Can, Fatma Betul; Schneider, Falk; Clausen, Mathias P.; Galiani, Silvia; Stanly, Tess A.; Waithe, Dominic; Colaco, Alexandria; Honigmann, Alf; Wüstner, Daniel; Platt, Frances; Eggeling, Christian

    2016-01-01

    Cholesterol (Chol) is a crucial component of cellular membranes, but knowledge of its intracellular dynamics is scarce. Thus, it is of utmost interest to develop tools for visualization of Chol organization and dynamics in cells and tissues. For this purpose, many studies make use of fluorescently labeled Chol analogs. Unfortunately, the introduction of the label may influence the characteristics of the analog, such as its localization, interaction, and trafficking in cells; hence, it is important to get knowledge of such bias. In this report, we compared different fluorescent lipid analogs for their performance in cellular assays: 1) plasma membrane incorporation, specifically the preference for more ordered membrane environments in phase-separated giant unilamellar vesicles and giant plasma membrane vesicles; 2) cellular trafficking, specifically subcellular localization in Niemann-Pick type C disease cells; and 3) applicability in fluorescence correlation spectroscopy (FCS)-based and super-resolution stimulated emission depletion-FCS-based measurements of membrane diffusion dynamics. The analogs exhibited strong differences, with some indicating positive performance in the membrane-based experiments and others in the intracellular trafficking assay. However, none showed positive performance in all assays. Our results constitute a concise guide for the careful use of fluorescent Chol analogs in visualizing cellular Chol dynamics. PMID:26701325

  5. Analogical Reasoning in Restructuring Scientific Knowledge.

    ERIC Educational Resources Information Center

    Mason, Lucia; Sorzio, Paolo

    1996-01-01

    Presents the results of an experiment that evaluated the efficiency of analogy in the conceptual restructuring of a science topic. The experiment involved a fifth-grade class studying water and heat flow. Discovered that analogy can act as an effective trigger for restructuring knowledge. (MJP)

  6. Structure Mapping in Analogy and Similarity.

    ERIC Educational Resources Information Center

    Gentner, Dedre; Markman, Arthur B.

    1997-01-01

    It is suggested that both similarity and analogy involve a process of structural alignment and mapping. The structure mapping process is described as it has been worked out for analogy, and this view is then extended to similarity and used to generate new predictions. (SLD)

  7. Analogical Processes and College Developmental Reading

    ERIC Educational Resources Information Center

    Paulson, Eric J.

    2014-01-01

    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…

  8. Understanding the Development of Analogical Reasoning Ability.

    ERIC Educational Resources Information Center

    Goldman, Susan R.; Bisanz, Jeffrey

    This paper takes the position that theories about individual differences in childhood and theories about cognitive development both would be enhanced if the two lines of research were integrated. The heuristic value of this position is illustrated in the context of analogical reasoning tasks. A general model of analogy solution and potential…

  9. Children's Use of Analogy during Collaborative Reasoning

    ERIC Educational Resources Information Center

    Lin, Tzu-Jung; Anderson, Richard C.; Hummel, John E.; Jadallah, May; Miller, Brian W.; Nguyen-Jahiel, Kim; Morris, Joshua A.; Kuo, Li-Jen; Kim, Il-Hee; Wu, Xiaoying; Dong, Ting

    2012-01-01

    This microgenetic study examined social influences on children's development of analogical reasoning during peer-led small-group discussions of stories about controversial issues. A total of 277 analogies were identified among 7,215 child turns for speaking during 54 discussions from 18 discussion groups in 6 fourth-grade classrooms (N = 120; age…

  10. Rotanone analogs: method of preparation and use

    DOEpatents

    VanBrocklin, Henry F; O& #x27; Neil, James P; Gibbs, Andrew R; Erathodiyil, Nandanan

    2013-10-08

    The present invention provides rotenone analogs and methods of making and using them. Labeled with single photon and positron emitting isotopes, the rotenone analogs of the present invention are useful in, for example, clinical imaging applications as tracers to measure cardiac blood flow and detect regions of ischemia.

  11. The Pennies-as-Electrons Analogy

    ERIC Educational Resources Information Center

    Ashmann, Scott

    2009-01-01

    Everyday experiences familiarize students with the ways in which electricity is used, but often the underlying concepts remain a mystery. Teachers often use analogies to help students relate the flow of electrons to other common systems, but many times these analogies are incomplete and lead to more student misconceptions. However, the "pass the…

  12. Using Analogies to Develop Conceptual Abilities.

    ERIC Educational Resources Information Center

    Jorgensen, Sally

    Because analogies are such powerful tools for communicating they should be exploited more consciously for instructional purposes. Unfortunately, analogies as a topic of investigation in the school curriculum tend to surface only as a subheading within a figurative language lesson in English class or as a test item on the SAT, MAT, or GRE. Analogy…

  13. Antibacterial and Antibiofilm Activities of Makaluvamine Analogs

    PubMed Central

    Nijampatnam, Bhavitavya; Nadkarni, Dwayaja H.; Wu, Hui; Velu, Sadanandan E.

    2014-01-01

    Streptococcus mutans is a key etiological agent in the formation of dental caries. The major virulence factor is its ability to form biofilms. Inhibition of S. mutans biofilms offers therapeutic prospects for the treatment and the prevention of dental caries. In this study, 14 analogs of makaluvamine, a marine alkaloid, were evaluated for their antibacterial activity against S. mutans and for their ability to inhibit S. mutans biofilm formation. All analogs contained the tricyclic pyrroloiminoquinone core of makaluvamines. The structural variations of the analogs are on the amino substituents at the 7-position of the ring and the inclusion of a tosyl group on the pyrrole ring N of the makaluvamine core. The makaluvamine analogs displayed biofilm inhibition with IC50 values ranging from 0.4 μM to 88 μM. Further, the observed bactericidal activity of the majority of the analogs was found to be consistent with the anti-biofilm activity, leading to the conclusion that the anti-biofilm activity of these analogs stems from their ability to kill S. mutans. However, three of the most potent N-tosyl analogs showed biofilm IC50 values at least an order of magnitude lower than that of bactericidal activity, indicating that the biofilm activity of these analogs is more selective and perhaps independent of bactericidal activity. PMID:25767719

  14. Piperazine-based nucleic acid analogs

    DOEpatents

    Schmidt, Jurgen; Silks, Louis A.; Michalczyk, Ryszard

    2005-01-11

    A novel nucleoside analog is disclosed which comprises a piperazine ring in the place of the ring ribose or deoxyribose sugar. Monomers utilizing a broad variety of nucleobases are disclosed, as well as oligomers comprising the monomers disclosed herein linked by a variety of linkages, including amide, phosphonamide, and sulfonamide linkages. A method of synthesizing the nucleoside analogs is also disclosed.

  15. The Multidimensionality of Verbal Analogy Items

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  16. Mathematical Analogs and the Teaching of Fractions.

    ERIC Educational Resources Information Center

    Charles, Kathy; Nason, Rod; Cooper, Tom

    The literature has noted that some mathematical analogs are more effective than others for the teaching of fractions. This study aimed to evaluate the efficacy of seven mathematical analogs commonly used in the teaching of the partitive quotient fraction construct. A sample of twelve purposively selected Year Three children were presented with…

  17. A Mechanical Analogy for the Photoelectric Effect

    ERIC Educational Resources Information Center

    Kovacevic, Milan S.; Djordjevich, Alexandar

    2006-01-01

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

  18. Young Children's Analogical Reasoning in Science Domains

    ERIC Educational Resources Information Center

    Haglund, Jesper; Jeppsson, Fredrik; Andersson, Johanna

    2012-01-01

    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…

  19. An Analog Computer for Electronic Engineering Education

    ERIC Educational Resources Information Center

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

    2011-01-01

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

  20. Novel Analog For Muscle Deconditioning

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    Existing models of muscle deconditioning are cumbersome and expensive (ex: bedrest). 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 post-flight astronaut performance data using the same tasks. Spline regression 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, knee extension (KE) isokinetic/BW of 6 Nm/Kg and KE torque/BW of 1.9 Nm/kg. Conclusions: Laboratory manipulation of strength / BW has promise as an appropriate analog for spaceflight-induced loss of muscle function for predicting occupational task performance and establishing operationally relevant exercise targets.

  1. Novel Analog For Muscle Deconditioning

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  2. Auditory, visual, and auditory-visual processing performance in typically developing children: modality independence versus dependence.

    PubMed

    Pillai, Roshni; Yathiraj, Asha

    2015-02-01

    The study was carried out to determine whether cross-modal interactions occur during processing of auditory and/or visual signals that require separation/closure, integration, and duration pattern perception in typically developing children. Thirty typically developing children were evaluated on three auditory processing tests (speech-in-noise test in Indian-English, dichotic-consonant vowel test, and duration pattern test) that tapped separation/closure, integration and duration pattern perception. The children were also evaluated on the visual and auditory-visual analogues of the auditory tests. Differences in modality were found in each of the processes that were tested. The performance when the auditory and visual modalities were tested simultaneously was significantly higher than the auditory or visual modality for tests that involved separation/closure and integration. In contrast, scores on the analogous auditory-visual duration pattern test were significantly higher than the auditory test but not the visual analogous test. Further, the scores of the auditory modality were significantly poorer than the visual modality for separation/closure and duration patterning but not for integration. Findings of the study indicate that performance on higher level processing varies depending on the modality that is assessed and supports the presence of cross-modality interactions.

  3. Visual cognition

    SciTech Connect

    Pinker, S.

    1985-01-01

    This collection of research papers on visual cognition first appeared as a special issue of Cognition: International Journal of Cognitive Science. The study of visual cognition has seen enormous progress in the past decade, bringing important advances in our understanding of shape perception, visual imagery, and mental maps. Many of these discoveries are the result of converging investigations in different areas, such as cognitive and perceptual psychology, artificial intelligence, and neuropsychology. This volume is intended to highlight a sample of work at the cutting edge of this research area for the benefit of students and researchers in a variety of disciplines. The tutorial introduction that begins the volume is designed to help the nonspecialist reader bridge the gap between the contemporary research reported here and earlier textbook introductions or literature reviews.

  4. An Analog Earth Climate Model

    NASA Astrophysics Data System (ADS)

    Varekamp, J. C.

    2010-12-01

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

  5. Analog regulation of metabolic demand

    PubMed Central

    2011-01-01

    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 results show that DNA

  6. Investigation of Celestial Solid Analogs

    NASA Technical Reports Server (NTRS)

    Sievers, A. J.

    2003-01-01

    Our far infrared studies of both hydrophobic and hydrophilic aerogel grains have demonstrated that the mm and sub-mm wave absorption produced by the fundamental two level systems (TLS) mechanism represents a more significant contribution for these open grain structures than for bulk amorphous silicate grains. We found that the region with the anomalous temperature dependence of the spectral index due to the TLS excitations can extend in a fluffy material up to 80 per cm, which is well beyond its typical upper limit for bulk glasses. Currently there is no theoretical explanation for this surprising result. The effects of reduced dimensionality on the optical properties of carbonaceous grains have been studied with a systematic investigation of carbon aerogels. This spectroscopic approach has permitted a more reliable determination of the single grain mass normalized absorption coefficient based on the experimentally determined characteristics of the fluffy material rather than on first principles calculations involving the bulk properties of the substance. Our finding is that the electrical connectivity of the material is the main factor affecting its far infrared absorption coefficient. Another one of the main constituents of the interstellar dust, amorphous ice, has been investigated in the mm-wave region both in the high (HDA) and low (LDA) density amorphous phases and as a function of impurities. We found that doping either phase with ionic (LiCl) or molecular (methanol) impurities decreases the difference in the mm-wave absorption coefficient between the HDA and LDA ice phases so that the HDA spectrum can be used as an analog for impure ice absorption in the far infrared spectral region.

  7. Namibian Analogs To Titan Dunes

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

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

  8. Visualizing inequality

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo

    2016-07-01

    The study of socioeconomic inequality is of substantial importance, scientific and general alike. The graphic visualization of inequality is commonly conveyed by Lorenz curves. While Lorenz curves are a highly effective statistical tool for quantifying the distribution of wealth in human societies, they are less effective a tool for the visual depiction of socioeconomic inequality. This paper introduces an alternative to Lorenz curves-the hill curves. On the one hand, the hill curves are a potent scientific tool: they provide detailed scans of the rich-poor gaps in human societies under consideration, and are capable of accommodating infinitely many degrees of freedom. On the other hand, the hill curves are a powerful infographic tool: they visualize inequality in a most vivid and tangible way, with no quantitative skills that are required in order to grasp the visualization. The application of hill curves extends far beyond socioeconomic inequality. Indeed, the hill curves are highly effective 'hyperspectral' measures of statistical variability that are applicable in the context of size distributions at large. This paper establishes the notion of hill curves, analyzes them, and describes their application in the context of general size distributions.

  9. Visualization tools: Models, representations and knowledge integration

    NASA Astrophysics Data System (ADS)

    Foley, Brian John

    Learning science requires students to make inferences and draw conclusions about concepts that are abstract, invisible or otherwise difficult to imagine. Scientific visualization is one way to make science and scientific thinking more visible to students. This dissertation investigates how visualization can be utilized for science education by studying how students integrate information from visualizations into their thinking. For this study, I developed a series of computer visualizations depicting thermodynamic phenomena. Thermodynamics is a topic that is both fundamental for several branches of science and difficult for many students to master (Linn & Songer, 1991). The design of the visualizations was learner centered. Pilot studies suggested that a dot-density representation of temperature would present a visual analogy of temperature as a measure of heat energy density. Energy density is a powerful model that can help students explain everyday heating and cooling phenomena. Dot-density computer visualizations were introduced into a public middle school science class studying thermodynamics (N = 178). Half of the students used the visualizations, while the other half served as a control. Interviews, classwork and tests were collected from the students in order to determine how the visualizations affected students' learning. Although there were not significant differences in the posttests for the groups, the classwork during the semester showed that the visualizations did affect how students envisioned heat and temperature. Students could often apply the energy density model in their reasoning during visualization activities, but when the visualizations were unavailable, many students applied less useful models. The interviews illustrated several difficulties that students had in learning from the visualizations. Some students interpreted the visualizations to support their existing conceptions of heat. Other students needed to have a visualization present to

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

    ERIC Educational Resources Information Center

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

    2007-01-01

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

  11. Observed Methods for Generating Analogies in Scientific Problem Solving. Revised.

    ERIC Educational Resources Information Center

    Clement, John

    Evidence from video tapes of experts thinking aloud and using analogies in scientific problem solving is presented. Four processes appear to be important in using an analogy: (1) generating the analogy; (2) establishing confidence in the validity of the analogy relation; (3) understanding the analogous case; and (4) applying findings to the…

  12. Fostering Multilateral Involvement in Analog Research

    NASA Technical Reports Server (NTRS)

    Cromwell, Ronita L.

    2015-01-01

    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.

  13. Gamma Oscillations and Visual Binding

    NASA Astrophysics Data System (ADS)

    Robinson, Peter A.; Kim, Jong Won

    2006-03-01

    At the root of visual perception is the mechanism the brain uses to analyze features in a scene and bind related ones together. Experiments show this process is linked to oscillations of brain activity in the 30-100 Hz gamma band. Oscillations at different sites have correlation functions (CFs) that often peak at zero lag, implying simultaneous firing, even when conduction delays are large. CFs are strongest between cells stimulated by related features. Gamma oscillations are studied here by modeling mm-scale patchy interconnections in the visual cortex. Resulting predictions for gamma responses to stimuli account for numerous experimental findings, including why oscillations and zero-lag synchrony are associated, observed connections with feature preferences, the shape of the zero-lag peak, and variations of CFs with attention. Gamma waves are found to obey the Schroedinger equation, opening the possibility of cortical analogs of quantum phenomena. Gamma instabilities are tied to observations of gamma activity linked to seizures and hallucinations.

  14. Analog detection for cavity lifetime spectroscopy

    DOEpatents

    Zare, Richard N.; Harb, Charles C.; Paldus, Barbara A.; Spence, Thomas G.

    2001-05-15

    An analog detection system for determining a ring-down rate or decay rate 1/.tau. of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

  15. Analog detection for cavity lifetime spectroscopy

    DOEpatents

    Zare, Richard N.; Harb, Charles C.; Paldus, Barbara A.; Spence, Thomas G.

    2003-01-01

    An analog detection system for determining a ring-down rate or decay rate 1/.tau. of an exponentially decaying ring-down beam issuing from a lifetime or ring-down cavity during a ring-down phase. Alternatively, the analog detection system determines a build-up rate of an exponentially growing beam issuing from the cavity during a ring-up phase. The analog system can be employed in continuous wave cavity ring-down spectroscopy (CW CRDS) and pulsed CRDS (P CRDS) arrangements utilizing any type of ring-down cavity including ring-cavities and linear cavities.

  16. Programmable Analog-To-Digital Converter

    NASA Technical Reports Server (NTRS)

    Kist, Edward H., Jr.

    1993-01-01

    High-speed analog-to-digital converter with programmable voltage steps that can be changed during operation. Allows concentration of converter resolution over specific portion of waveform. Particularly useful in digitizing wind-shear radar and lidar return signals, in digital oscilloscopes, and other applications in which desirable to increase digital resolution over specific area of waveform while accepting lower resolution over rest of waveform. Effective increase in dynamic range achieved without increase in number of analog-to-digital converter bits. Enabling faster analog-to-digital conversion.

  17. Camouflage Visualization

    DTIC Science & Technology

    1992-04-07

    results of the test are difficult to quantify and to compare with previous observations. The more recent need to develop camouflage measures to defeat...Number: 609-9160002 2-2 Final Report. Camouflage Visualization System A:)TTRIBU!TES)) EMTY ATmUE INSERT TARGET BACKROUND....... IMG IMMAGE IRSG- RHG...atmospheric attenuation models, such as LOWTRAN. As a reference, the calculated results are compared to LOWTRAN predictions to show the performance of our

  18. Battlefield Visualization

    DTIC Science & Technology

    2007-11-02

    A study analyzing battlefield visualization (BV) as a component of information dominance and superiority. This study outlines basic requirements for effective BV in terms of terrain data, information systems (synthetic environment; COA development and analysis tools) and BV development management, with a focus on technology insertion strategies. This study also reports on existing BV systems and provides 16 recommendations for Army BV support efforts, including interested organization, funding levels and duration of effort for each recommended action.

  19. Visualizing Progress

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Reality Capture Technologies, Inc. is a spinoff company from Ames Research Center. Offering e-business solutions for optimizing management, design and production processes, RCT uses visual collaboration environments (VCEs) such as those used to prepare the Mars Pathfinder mission.The product, 4-D Reality Framework, allows multiple users from different locations to manage and share data. The insurance industry is one targeted commercial application for this technology.

  20. Flow visualization

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M.

    1991-01-01

    Flow visualization techniques are reviewed, with particular attention given to those applicable to liquid helium flows. Three techniques capable of obtaining qualitative and quantitative measurements of complex 3D flow fields are discussed including focusing schlieren, particle image volocimetry, and holocinematography (HCV). It is concluded that the HCV appears to be uniquely capable of obtaining full time-varying, 3D velocity field data, but is limited to the low speeds typical of liquid helium facilities.

  1. Flow visualization

    NASA Astrophysics Data System (ADS)

    Weinstein, Leonard M.

    Flow visualization techniques are reviewed, with particular attention given to those applicable to liquid helium flows. Three techniques capable of obtaining qualitative and quantitative measurements of complex 3D flow fields are discussed including focusing schlieren, particle image volocimetry, and holocinematography (HCV). It is concluded that the HCV appears to be uniquely capable of obtaining full time-varying, 3D velocity field data, but is limited to the low speeds typical of liquid helium facilities.

  2. Computer Analogies: Teaching Molecular Biology and Ecology.

    ERIC Educational Resources Information Center

    Rice, Stanley; McArthur, John

    2002-01-01

    Suggests that computer science analogies can aid the understanding of gene expression, including the storage of genetic information on chromosomes. Presents a matrix of biology and computer science concepts. (DDR)

  3. Review of field-programmable analog arrays

    NASA Astrophysics Data System (ADS)

    Gulak, Glen; D'Mello, Dean R.

    1996-10-01

    The drive towards shorter design cycles for analog integrated circuits has given impetus to several developments in the area of field-programmable analog arrays (FPAAs). Various approaches have been taken in implementing topological and parametric programmability of analog circuits. Recent extensions of this work have married FPAAs to their digital counterparts (FPGAs) along with data conversion interfaces, to form field-programmable mixed signal arrays (FPMAs). This survey paper reviews work to data in the area of programmable analog and mixed signal circuits. The body of work reviewed includes university and industrial research, commercial products and patents. A time-line of important achievements in the area is drawn and the status of various activities is summarized.

  4. CMOS analog switches for adaptive filters

    NASA Technical Reports Server (NTRS)

    Dixon, C. E.

    1980-01-01

    Adaptive active low-pass filters incorporate CMOS (Complimentary Metal-Oxide Semiconductor) analog switches (such as 4066 switch) that reduce variation in switch resistance when filter is switched to any selected transfer function.

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

    ERIC Educational Resources Information Center

    Stewart, Peter A.

    1979-01-01

    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)

  6. Analog Computer Laboratory with Biological Examples.

    ERIC Educational Resources Information Center

    Strebel, Donald E.

    1979-01-01

    The use of biological examples in teaching applications of the analog computer is discussed and several examples from mathematical ecology, enzyme kinetics, and tracer dynamics are described. (Author/GA)

  7. NASA Now: Exploring Asteroids: An Analog Mission

    NASA Video Gallery

    NASA’s Extreme Environment Mission Operations, or NEEMO, project lead Bill Todd describes this analog mission and how aquanauts living and working in an undersea habitat are helping NASA prepare ...

  8. An Electrical Analog Computer for Poets

    ERIC Educational Resources Information Center

    Bruels, Mark C.

    1972-01-01

    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)

  9. Optical analog-to-digital converter

    DOEpatents

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

    2009-07-21

    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.

  10. Use of analogy in learning scientific concepts.

    PubMed

    Donnelly, C M; McDaniel, M A

    1993-07-01

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

  11. An Electronic Analog of the Diffraction Grating.

    ERIC Educational Resources Information Center

    MacLeod, A. M.

    1978-01-01

    Gives an outline description of electronic circuitry which is analogous to the optical diffraction grating or to crystals used in the Bragg reflection of X-rays or electron waves, and explains how to use it. (Author/GA)

  12. Analog hardware for learning neural networks

    NASA Technical Reports Server (NTRS)

    Eberhardt, Silvio P. (Inventor)

    1991-01-01

    This is a recurrent or feedforward analog neural network processor having a multi-level neuron array and a synaptic matrix for storing weighted analog values of synaptic connection strengths which is characterized by temporarily changing one connection strength at a time to determine its effect on system output relative to the desired target. That connection strength is then adjusted based on the effect, whereby the processor is taught the correct response to training examples connection by connection.

  13. ANALOG-TO-DIGITAL DATA CONVERTER

    DOEpatents

    Rodgers, G.W.; Althouse, J.E.; Anderson, D.P.; Bussey, G.R.; Minnear, L.H.

    1960-09-01

    Electrical apparatus is described, particularly useful in telemetry work, for converting analog signals into electrical pulses and recording them. An electronic editor commands the taking of signal readings at a frequency which varies according to linearity of the analog signal being converted. Readings of information signals are recorded, along with time base readings and serial numbering, if desired, on magnetic tape and the latter may be used to operate a computer or the like. Magnetic tape data may be transferred to punched cards.

  14. Synthetic heparin-binding growth factor analogs

    DOEpatents

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

    2007-01-23

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

  15. The analogy between stereo depth and brightness.

    PubMed

    Brookes, A; Stevens, K A

    1989-01-01

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

  16. Protein Structure Prediction with Visuospatial Analogy

    NASA Astrophysics Data System (ADS)

    Davies, Jim; Glasgow, Janice; Kuo, Tony

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

  17. The Corona of the Young Solar Analog EK Draconis

    NASA Technical Reports Server (NTRS)

    Gudel, M.; Schmitt, J. H. M. M.; Benz, A. O.; Elias, N. M., II

    1995-01-01

    (1-2) x 10(exp 10) cm, compatible with a few times the scale height of the cooler plasma component.

  18. Obduction: Why, how and where. Clues from analog models

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Obduction is an odd geodynamic process characterized by the emplacement of dense oceanic “ophiolites” atop light continental plates in convergent settings. We herein present analog models specifically designed to explore the conditions (i.e., sharp increase of plate velocities - herein coined as ‘acceleration’, slab interaction with the 660 km discontinuity, ridge subduction) under which obduction may develop as a result of subduction initiation. The experimental setup comprises an upper mantle modeled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and high-viscosity silicone plates. Convergence is simulated by pushing a piston with plate tectonics like velocities (1-10 cm/yr) onto a model comprising a continental margin, a weakness zone with variable resistance and dip (W), an oceanic plate (with or without a spreading ridge), a preexisting subduction zone (S) dipping away from the piston and an upper active continental margin, below which the oceanic plate is being subducted at the start of the model (as for the Neotethyan natural example). Several configurations were tested over thirty-five parametric models, with special emphasis on comparing different types of weakness zone and the degree of mechanical coupling across them. Measurements of displacements and internal deformation allow for a precise and reproducible tracking of deformation. Models consistently demonstrate that once conditions to initiate subduction are reached, obduction may develop further depending on the effective strength of W. Results (1) constrain the range of physical conditions required for obduction to develop/nucleate and (2) underline the key role of such perturbations for triggering obduction, particularly plate ‘acceleration’. They provide an explanation to the short-lived Peri-Arabic obduction, which took place along thousands of km almost synchronously (within ∼50-10 Myr), from Turkey to Oman, while the subduction zone beneath

  19. Students' Pre- and Post-Teaching Analogical Reasoning When They Draw their Analogies

    NASA Astrophysics Data System (ADS)

    Braga Mozzer, Nilmara; Justi, Rosária

    2012-02-01

    Analogies are parts of human thought. From them, we can acquire new knowledge or change that which already exists in our cognitive structure. In this sense, understanding the analogical reasoning process becomes an essential condition to understand how we learn. Despite the importance of such an understanding, there is no general agreement in cognitive science literature about this issue. In this study, we investigated students' analogical reasoning as a creative process where an environment was set up to foster the students' generating and explaining their own analogies. Data were gathered from pre- and post-teaching interviews, in which the 13-14-year-old students were asked to make comparisons that could explain how atoms are bound. Such data supported the discussion about how students reasoned analogically. Our results made it evident that the task aims and the students' salient knowledge exerted a great influence on the drawing of analogies.

  20. Optical domain analog to digital conversion methods and apparatus

    SciTech Connect

    Vawter, Gregory A

    2014-05-13

    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.

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

    NASA Technical Reports Server (NTRS)

    Prokop, Norman; Krasowski, Michael

    2013-01-01

    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.

  2. Visual bioethics.

    PubMed

    Lauritzen, Paul

    2008-12-01

    Although images are pervasive in public policy debates in bioethics, few who work in the field attend carefully to the way that images function rhetorically. If the use of images is discussed at all, it is usually to dismiss appeals to images as a form of manipulation. Yet it is possible to speak meaningfully of visual arguments. Examining the appeal to images of the embryo and fetus in debates about abortion and stem cell research, I suggest that bioethicists would be well served by attending much more carefully to how images function in public policy debates.

  3. Building a Gravitational Analogy of Electric Circuits Using LEGOs®

    NASA Astrophysics Data System (ADS)

    Butler, James J.; Townsend, E. A.

    2006-12-01

    One of the most powerful techniques that physicists have at their disposal is the ability to make analogies between different physical systems that share common characteristics. Physicists often use their familiarity with a phenomenon in one system to understand a similar phenomenon in an apparently unrelated system. They draw analogies, find commonalities, and examine how the principles that govern each system give rise to similar (or different) behaviors. This is one of the abilities that we want to instill in our students. Introductory physics students often find the concepts of potential difference, current, and resistance particularly challenging. This difficulty is compounded in the analysis of complicated electric circuits that involve combinations of series and parallel resistors. In order to help our students build a conceptual understanding of these systems, we have developed LEGO building exercises that expand on the well-known analogy between gravitational potential energy in mechanical systems and electrical potential energy in circuits. In this analogy a closed circuit is represented by a closed path made of LEGOs. The potential difference across a battery is represented by a sudden change in the height of the path, electrical resistors are represented by ramps with appropriate lengths and slopes, and electrical current is visualized as balls rolling along the path. These exercises are used in both the laboratory and the classroom. Students are required to build LEGO models along with the corresponding electric circuits and explain the analogies between the components of each.

  4. Analog Computer-Aided Detection (CAD) information can be more effective than binary marks.

    PubMed

    Cunningham, Corbin A; Drew, Trafton; Wolfe, Jeremy M

    2017-02-01

    In socially important visual search tasks, such as baggage screening and diagnostic radiology, experts miss more targets than is desirable. Computer-aided detection (CAD) programs have been developed specifically to improve performance in these professional search tasks. For example, in breast cancer screening, many CAD systems are capable of detecting approximately 90% of breast cancer, with approximately 0.5 false-positive detections per image. Nevertheless, benefits of CAD in clinical settings tend to be small (Birdwell, 2009) or even absent (Meziane et al., 2011; Philpotts, 2009). The marks made by a CAD system can be "binary," giving the same signal to any location where the signal is above some threshold. Alternatively, a CAD system presents an analog signal that reflects strength of the signal at a location. In the experiments reported, we compare analog and binary CAD presentations using nonexpert observers and artificial stimuli defined by two noisy signals: a visible color signal and an "invisible" signal that informed our simulated CAD system. We found that analog CAD generally yielded better overall performance than binary CAD. The analog benefit is similar at high and low target prevalence. Our data suggest that the form of the CAD signal can directly influence performance. Analog CAD may allow the computer to be more helpful to the searcher.

  5. Analog forecasting with dynamics-adapted kernels

    NASA Astrophysics Data System (ADS)

    Zhao, Zhizhen; Giannakis, Dimitrios

    2016-09-01

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

  6. Analogy, higher order thinking, and education.

    PubMed

    Richland, Lindsey Engle; Simms, Nina

    2015-01-01

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

  7. Magnetic activity of seismic solar analogs

    NASA Astrophysics Data System (ADS)

    Salabert, D.; García, R. A.; Beck, P. G.

    2016-12-01

    We present our latest results on the solar-stellar connection by studying 18 solar analogs that we identified among the Kepler seismic sample tep{salabert16a}. We measured their magnetic activity properties using observations collected by the Kepler satellite and the ground-based, high-resolution HERMES spectrograph. The photospheric (S{_ph}) and chromospheric (S) magnetic activity proxies of these seismic solar analogs are compared in relation to solar activity. We show that the activity of the Sun is actually comparable to the activity of the seismic solar analogs. Furthermore, we report on the discovery of temporal variability in the acoustic frequencies of the young (1 Gyr-old) solar analog KIC 10644253 with a modulation of about 1.5 years, which agrees with the derived photospheric activity tep{salabert16b}. It could actually be the signature of the short-period modulation, or quasi-biennal oscillation, of its magnetic activity as observed in the Sun and the 1-Gyr-old solar analog HD 30495. In addition, the lithium abundance and the chromospheric activity estimated from HERMES confirms that KIC 10644253 is a young and more active star than the Sun.

  8. NaturAnalogs for the Unsaturated Zone

    SciTech Connect

    A. Simmons; A. Unger; M. Murrell

    2000-03-08

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

  9. DOTA-Derivatives of Octreotide Dicarba-Analogs with High Affinity for Somatostatin sst2,5 Receptors

    PubMed Central

    Pratesi, Alessandro; Ginanneschi, Mauro; Lumini, Marco; Papini, Anna M.; Novellino, Ettore; Brancaccio, Diego; Carotenuto, Alfonso

    2017-01-01

    In vivo somatostatin receptor scintigraphy is a valuable method for the visualization of human endocrine tumors and their metastases. In fact, peptide ligands of somatostatin receptors (sst's) conjugated with chelating agents are in clinical use. We have recently developed octreotide dicarba-analogs, which show interesting binding profiles at sst's. In this context, it was mandatory to explore the possibility that our analogs could maintain their activity also upon conjugation with DOTA. In this paper, we report and discuss the synthesis, binding affinity and conformational preferences of three DOTA-conjugated dicarba-analogs of octreotide. Interestingly, two conjugated analogs exhibited nanomolar affinities on sst2 and sst5 somatostatin receptor subtypes. PMID:28286746

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  11. The Effect of Analogy-Based Teaching on Students' Achievement and Students' Views about Analogies

    ERIC Educational Resources Information Center

    Genc, Murat

    2013-01-01

    The purpose of this study is to determine the effect of the analogy-based teaching on students' achievement and students' views about analogies. In this research, Solomon group design which is one of the experimental designs, was implemented. The sample of the research consists of 108 students in four 6th grade classes in Turkey. The achievement…

  12. Value and Limitations of Analogs in Teaching Mathematics.

    ERIC Educational Resources Information Center

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

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

  13. The Importance of Explicitly Mapping Instructional Analogies in Science Education

    ERIC Educational Resources Information Center

    Asay, Loretta Johnson

    2013-01-01

    Analogies are ubiquitous during instruction in science classrooms, yet research about the effectiveness of using analogies has produced mixed results. An aspect seldom studied is a model of instruction when using analogies. The few existing models for instruction with analogies have not often been examined quantitatively. The Teaching With…

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  15. Visualization rhetoric: framing effects in narrative visualization.

    PubMed

    Hullman, Jessica; Diakopoulos, Nicholas

    2011-12-01

    Narrative visualizations combine conventions of communicative and exploratory information visualization to convey an intended story. We demonstrate visualization rhetoric as an analytical framework for understanding how design techniques that prioritize particular interpretations in visualizations that "tell a story" can significantly affect end-user interpretation. We draw a parallel between narrative visualization interpretation and evidence from framing studies in political messaging, decision-making, and literary studies. Devices for understanding the rhetorical nature of narrative information visualizations are presented, informed by the rigorous application of concepts from critical theory, semiotics, journalism, and political theory. We draw attention to how design tactics represent additions or omissions of information at various levels-the data, visual representation, textual annotations, and interactivity-and how visualizations denote and connote phenomena with reference to unstated viewing conventions and codes. Classes of rhetorical techniques identified via a systematic analysis of recent narrative visualizations are presented, and characterized according to their rhetorical contribution to the visualization. We describe how designers and researchers can benefit from the potentially positive aspects of visualization rhetoric in designing engaging, layered narrative visualizations and how our framework can shed light on how a visualization design prioritizes specific interpretations. We identify areas where future inquiry into visualization rhetoric can improve understanding of visualization interpretation.

  16. Gravitoelectromagnetic analogy based on tidal tensors

    SciTech Connect

    Costa, L. Filipe O.; Herdeiro, Carlos A. R.

    2008-07-15

    We propose a new approach to a physical analogy between general relativity and electromagnetism, based on tidal tensors of both theories. Using this approach we write a covariant form for the gravitational analogues of the Maxwell equations, which makes transparent both the similarities and key differences between the two interactions. The following realizations of the analogy are given. The first one matches linearized gravitational tidal tensors to exact electromagnetic tidal tensors in Minkowski spacetime. The second one matches exact magnetic gravitational tidal tensors for ultrastationary metrics to exact magnetic tidal tensors of electromagnetism in curved spaces. In the third we show that our approach leads to a two-step exact derivation of Papapetrou's equation describing the force exerted on a spinning test particle. Analogous scalar invariants built from tidal tensors of both theories are also discussed.

  17. Polymeric nanogel formulations of nucleoside analogs

    PubMed Central

    Vinogradov, Serguei V

    2008-01-01

    Nanogels are colloidal microgel carriers that have been introduced recently as a prospective drug delivery system for nucleotide therapeutics. The crosslinked protonated polymer network of nanogels binds oppositely charged drug molecules, encapsulating them into submicron particles with a core-shell structure. The nanogel network also provides a suitable template for chemical engineering, surface modification and vectorisation. This review reveals recent attempts to develop novel drug formulations of nanogels with antiviral and antiproliferative nucleoside analogs in the active form of 5′-triphosphates; discusses structural approaches to the optimisation of nanogel properties, and; discusses the development of targeted nanogel drug formulations for systemic administration. Notably, nanogels can improve the CNS penetration of nucleoside analogs that are otherwise restricted from passing across the blood–brain barrier. The latest findings reviewed here demonstrate an efficient intracellular release of nucleoside analogs, encouraging further applications of nanogel carriers for targeted drug delivery. PMID:17184158

  18. Changes in analogical reasoning in adulthood.

    PubMed

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

    1990-01-01

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

  19. Interaction of Chloramphenicol Tripeptide Analogs with Ribosomes.

    PubMed

    Tereshchenkov, A G; Shishkina, A V; Tashlitsky, V N; Korshunova, G A; Bogdanov, A A; Sumbatyan, N V

    2016-04-01

    Chloramphenicol amine peptide derivatives containing tripeptide fragments of regulatory "stop peptides" - MRL, IRA, IWP - were synthesized. The ability of the compounds to form ribosomal complexes was studied by displacement of the fluorescent erythromycin analog from its complex with E. coli ribosomes. It was found that peptide chloramphenicol analogs are able to bind to bacterial ribosomes. The dissociation constants were 4.3-10 µM, which is 100-fold lower than the corresponding values for chloramphenicol amine-ribosome complex. Interaction of the chloramphenicol peptide analogs with ribosomes was simulated by molecular docking, and the most probable contacts of "stop peptide" motifs with the elements of nascent peptide exit tunnel were identified.

  20. Trench Visualization

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image shows oblique views of NASA's Phoenix Mars Lander's trench visualized using the NASA Ames Viz software package that allows interactive movement around terrain and measurement of features. The Surface Stereo Imager images are used to create a digital elevation model of the terrain. The trench is 1.5 inches deep. The top image was taken on the seventh Martian day of the mission, or Sol 7 (June 1, 2008). The bottom image was taken on the ninth Martian day of the mission, or Sol 9 (June 3, 2008).

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  1. Associative Pattern Recognition In Analog VLSI Circuits

    NASA Technical Reports Server (NTRS)

    Tawel, Raoul

    1995-01-01

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

  2. Fungitoxicity of chemical analogs with heartwood toxins.

    PubMed

    Grohs, B M; Kunz, B

    1998-07-01

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

  3. Analogies between elastic and capillary interfaces*

    NASA Astrophysics Data System (ADS)

    Snoeijer, Jacco H.

    2016-10-01

    In this paper we exploit some analogies between flows near capillary interfaces and near elastic interfaces. We first consider the elastohydrodynamics of a ball bearing and the motion of a gas bubble inside a thin channel. It is shown that there is a strong analogy between these two lubrication problems, and the respective scaling laws are derived side by side. Subsequently, the paper focuses on the limit where the involved elastic interfaces become extremely soft. It is shown that soft gels and elastomers, like liquids, can be shaped by their surface tension. We highlight some recent advances on this class of elastocapillary phenomena.

  4. Analog graphic display method and apparatus

    DOEpatents

    Kronberg, James W.

    1991-01-01

    An apparatus and method for using an output device such as an LED to show the approximate analog level of a variable electrical signal wherein a modulating AC waveform is superimposed either on the signal or a reference voltage, both of which are then fed to a comparator which drives the output device. Said device flashes at a constant perceptible rate with a duty cycle which varies in response to variations in the level of the input signal. The human eye perceives these variations in duty cycle as analogous to variations in the level of the input signal.

  5. Analog graphic display method and apparatus

    DOEpatents

    Kronberg, J.W.

    1991-08-13

    Disclosed are an apparatus and method for using an output device such as an LED to show the approximate analog level of a variable electrical signal wherein a modulating AC waveform is superimposed either on the signal or a reference voltage, both of which are then fed to a comparator which drives the output device. Said device flashes at a constant perceptible rate with a duty cycle which varies in response to variations in the level of the input signal. The human eye perceives these variations in duty cycle as analogous to variations in the level of the input signal. 21 figures.

  6. Discrete analog computing with rotor-routers.

    PubMed

    Propp, James

    2010-09-01

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

  7. Transparent Analogs for Alloy Phase Studies

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  8. Space flight nutrition research: platforms and analogs

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  9. Synthetic heparin-binding factor analogs

    DOEpatents

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

    2010-04-20

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

  10. Binary/Analog CCD Correlator Development.

    DTIC Science & Technology

    1981-07-01

    AD-AI04 438 TEXAS INSTRUMENTS INC DALLAS F/ 9 /5 BINARY/ANALOG CCD COPPEL TOR DE VELOPMEN.(U JUL 81 R A HAKEN F19628-78-C-0122 CLASSIFIED TI -08-79...ANALOG CCD CORRELATOR DEVELOPMENT Texas Instruments Inc. R. A. Hakln APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLMITED DTIC S ELECTE SEP 211981i D...transversal filter with split-electrode weighting is well recogniied as a useful tool liInumher of sampled-data filtering applications.’ However, these

  11. Parallel Analog-to-Digital Image Processor

    NASA Technical Reports Server (NTRS)

    Lokerson, D. C.

    1987-01-01

    Proposed integrated-circuit network of many identical units convert analog outputs of imaging arrays of x-ray or infrared detectors to digital outputs. Converter located near imaging detectors, within cryogenic detector package. Because converter output digital, lends itself well to multiplexing and to postprocessing for correction of gain and offset errors peculiar to each picture element and its sampling and conversion circuits. Analog-to-digital image processor is massively parallel system for processing data from array of photodetectors. System built as compact integrated circuit located near local plane. Buffer amplifier for each picture element has different offset.

  12. Pseudolog Digital-to-Analog Converter

    NASA Technical Reports Server (NTRS)

    Gooder, S. T.

    1986-01-01

    Sensitivity decreases by 10 at beginning of each input decade. Method conceived to convert binary-coded data to suitable linear form for stripchart recording. Strip-chart recordings obtained from typical pressure readings in a vacuum system during pumpdown. In reading curve, BCD digital vacuum-gage output processed by analog-to-digital converter in such way that only reading digits (but not range) appear in output. In range and reading, range also converted to analog and placed as most significant digit.

  13. A quadratic analog-to-digital converter

    NASA Technical Reports Server (NTRS)

    Harrison, D. C.; Staples, M. H.

    1980-01-01

    An analog-to-digital converter with a square root transfer function has been developed for use with a pair of CCD imaging detectors in the White Light Coronagraph/X-ray XUV Telescope experiment to be flown as part of the Internal Solar Polar Mission. It is shown that in background-noise-limited instrumentation systems a quadratic analog-to-digital converter will allow a maximum dynamic range with a fixed number of data bits. Low power dissipation, moderately fast conversion time, and reliability are achieved in the proposed design using standard components and avoiding nonlinear elements.

  14. Bayesian Planet Searches for the 10 cm/s Radial Velocity Era

    NASA Astrophysics Data System (ADS)

    Gregory, Philip C.

    2016-10-01

    A new apodized Keplerian model is proposed for the analysis of precision radial velocity (RV) data to model both planetary and stellar activity (SA) induced RV signals. A symmetrical Gaussian apodization function with unknown width and center can distinguish planetary signals from SA signals on the basis of the width of the apodization function. The general model for m apodized Keplerian signals also includes a linear regression term between RV and the stellar activity diagnostic In (R'hk), as well as an extra Gaussian noise term with unknown standard deviation. The model parameters are explored using a Bayesian fusion MCMC code. A differential version of the Generalized Lomb-Scargle periodogram provides an additional way of distinguishing SA signals and helps guide the choice of new periods. Sample results are reported for a recent international RV blind challenge which included multiple state of the art simulated data sets supported by a variety of stellar activity diagnostics.

  15. A 10 cm dual frequency Doppler weather radar. Part 1: The radar system

    NASA Astrophysics Data System (ADS)

    Bishop, A. W.; Armstrong, G. M.

    1982-10-01

    Design concepts and test results are summarized for a Doppler weather radar system suitable for precipitation measurements over a wide span of radial velocities and slant ranges, even in the presence of ground clutter. The radar transmits two uniform pulse trains at 2.710 and 2.760 GHz. Uniformly spaced pulses permit ground clutter cancellation of up to 50 dB to be achieved with a three-pole elliptic filter. Pulse spacing at one frequency is consistent with long-range coverage in reflectivity, while spacing of the second is consistent with a wide unambiguous velocity measurement span.

  16. Laboratory Visualization of Hydraulic Fracture Propagation and Interaction with a Network of Preexisting Fractures

    NASA Astrophysics Data System (ADS)

    Nakagawa, S.; Kneafsey, T. J.; Borglin, S. E.

    2015-12-01

    We present optical visualization experiments of hydraulic fracture propagation within transparent rock-analogue samples containing a network of preexisting fractures. Natural fractures and heterogeneities in rock have a great impact on hydraulic fracture propagation and resulting improvements in reservoir permeability. In recent years, many sophisticated numerical simulations on hydraulic fracturing have been conducted. Laboratory experiments on hydraulic fracturing are often performed with acoustic emission (Micro Earthquake) monitoring, which allows detection and location of fracturing and fracture propagation. However, the detected fractures are not necessarily hydraulically produced fractures which provide permeable pathways connected to the injection (and production) well. The primary objectives of our visualization experiments are (1) to obtain quantitative visual information of hydraulic fracture propagation affected by pre-existing fractures and (2) to distinguish fractures activated by the perturbed stress field away from the injected fluid and hydraulically produced fractures. The obtained data are also used to develop and validate a new numerical modeling technique (TOUGH-RBSN [Rigid-Body-Spring-Network] model) for hydraulic fracturing simulations, which is presented in a companion paper. The experiments are conducted using transparent soda-lime glass cubes (10 cm × 10 cm × 10 cm) containing either (1) 3D laser-engraved artificial fractures and fracture networks or (2) a random network of fractures produced by rapid thermal quenching. The strength (and also the permeability for the latter) of the fractures can be altered to examine their impact on hydraulic fracturing. The cubes are subjected to true-triaxial stress within a polyaxial loading frame, and hydraulic fractures are produced by injecting fluids with a range of viscosity into an analogue borehole drilled in the sample. The visual images of developing fractures are obtained both through a port

  17. Multichannel analog front-end and analog-to-digital converter ICs for silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Bocharov, Y. I.; Butuzov, V. A.

    2016-10-01

    Integrated circuit (IC) of multichannel analog front-end and a mixed-signal chip of multichannel analog-to-digital converter are presented. A chipset of these two ICs is intended for readout, analog preprocessing and analog to digital conversion of silicon photomultiplier array signals. The number of channels of the analog front-end IC as well as the types of their input stages depends on the application. The current test version of the chip contains three current-input channels and three voltage-input channels. Each of the channels includes a programmable pre-amplifier, integrator with baseline-holder, code-controlled amplifier, amplitude discriminator, two programmable timers, pulse-shaping low-pass filter, peak detector, and an output buffer with baseline tuning circuitry. The analog IC has code-configurable architecture. The mixed-signal IC includes nine main channels and one auxiliary channel, containing 10-bit analog-to-digital converter in each channel. It also has a buffer memory and a voltage reference. The chip features low power consumption, which is less than 0.5 mW per channel at a sampling rate of 100 kHz. Both ICs are implemented in 0.35 μm CMOS technology.

  18. Direct visualization of replication dynamics in early zebrafish embryos.

    PubMed

    Kuriya, Kenji; Higashiyama, Eriko; Avşar-Ban, Eriko; Okochi, Nanami; Hattori, Kaede; Ogata, Shin; Takebayashi, Shin-Ichiro; Ogata, Masato; Tamaru, Yutaka; Okumura, Katsuzumi

    2016-05-01

    We analyzed DNA replication in early zebrafish embryos. The replicating DNA of whole embryos was labeled with the thymidine analog 5-ethynyl-2'-deoxyuridine (EdU), and spatial regulation of replication sites was visualized in single embryo-derived cells. The results unveiled uncharacterized replication dynamics during zebrafish early embryogenesis.

  19. Why Teach Visual Culture?

    ERIC Educational Resources Information Center

    Passmore, Kaye

    2007-01-01

    Visual culture is a hot topic in art education right now as some teachers are dedicated to teaching it and others are adamant that it has no place in a traditional art class. Visual culture, the author asserts, can include just about anything that is visually represented. Although people often think of visual culture as contemporary visuals such…

  20. Invention through Form and Function Analogy

    ERIC Educational Resources Information Center

    Rule, Audrey C.

    2015-01-01

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

  1. Metaphor, Simile, Analogy and the Brain

    ERIC Educational Resources Information Center

    Riddell, Patricia

    2016-01-01

    Fox argues that the poetic function of language fulfils the human need to symbolise. Metaphor, simile and analogy provide examples of the ways in which symbolic language can be used creatively. The neural representations of these processes therefore provide a means to determine the neurological basis of creative language. Neuro-imaging has…

  2. Analogies and Reconstruction of Mathematical Knowledge.

    ERIC Educational Resources Information Center

    Fast, Gerald R.

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

  3. Reasoning by Analogy in Solving Comparison Problems.

    ERIC Educational Resources Information Center

    English, Lyn D.

    1998-01-01

    Investigates 10-year-old children's abilities to reason by analogy in solving addition and subtraction comparison problems involving unknown compare sets and unknown reference sets. Children responded in a consistent manner to the tasks involving the basic addition problems, indicating substantial relational knowledge of these but responded in an…

  4. (-)-Botryodiplodin, A Unique Ribose Analog Toxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many toxins owe their mechanisms of action to being structural analogs of essential metabolites, messengers or structural components. Examples range from tubo-curare to penicillin. Ribose plays a unique role in the metabolism of living organisms, whether prokaryotes or eukaryotes. It and its deri...

  5. An Analog Processor for Image Compression

    NASA Technical Reports Server (NTRS)

    Tawel, R.

    1992-01-01

    This paper describes a novel analog Vector Array Processor (VAP) that was designed for use in real-time and ultra-low power image compression applications. This custom CMOS processor is based architectually on the Vector Quantization (VQ) algorithm in image coding, and the hardware implementation fully exploits the inherent parallelism built-in the VQ algorithm.

  6. Aromatic Bagels: An Edible Resonance Analogy

    NASA Astrophysics Data System (ADS)

    Lin, Shirley

    2007-05-01

    A classroom demonstration involving the use of a bagel and cream cheese as an analogy for the two resonance contributors of benzene is described. This method emphasizes the deficiencies of using a single Lewis structure to describe the structure of benzene. Students are also reminded that benzene is a single entity and not a species that oscillates between two resonance contributors.

  7. The GMO-Nanotech (Dis)Analogy?

    ERIC Educational Resources Information Center

    Sandler, Ronald; Kay, W. D.

    2006-01-01

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

  8. Analog Acoustic Expression in Speech Communication

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  9. Radiation Behavior of Analog Neural Network Chip

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    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.

  10. Resistance Gene Analogs in Cherries (Prunus spp.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic studies have shown that NBS-LRR Resistance Gene Analogs (RGAs) tend to occur in clusters and often map to major resistances gene or QTL. The identification and use of specific RGAs as molecular markers among plant material displaying differential resistance phenotypes has the potential to di...

  11. Oseltamivir analog with boron cluster modulator.

    PubMed

    Adamska, Anna; Olejniczak, Agnieszka B; Zwoliński, Krzysztof; Szczepek, Wojciech J; Król, Ewelina; Szewczyk, Bogusław; Grynkiewicz, Grzegorz; Leśnikowski, Zbigniew J

    2012-01-01

    Synthesis of novel neuraminidase inhibitor -- carborane ester of oseltamivir carboxylic acid is described, and its physicochemical and spectral characteristics is provided. Surprisingly, carborane analog of oseltamivir is of an order of magnitude less active than its precursor, the corresponding ethyl ester, which is the active principle of pharmaceutical preparations used in influenza prophylactics and therapy.

  12. Image Quality in Analog and Digital Microtechniques.

    ERIC Educational Resources Information Center

    White, William

    1991-01-01

    Discusses the basic principles of the application of microfilm (analog) and electronic (digital) technologies for data storage. Image quality is examined, searching and retrieval capabilities are considered, and hardcopy output resolution is described. It is concluded that microfilm is still the preferred archival medium. (5 references) (LRW)

  13. A Mechanical Analogy for Ohm's Law.

    ERIC Educational Resources Information Center

    do Couto Tavares, Milton; And Others

    1991-01-01

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

  14. Multivariate Analog of Hays Omega-Squared.

    ERIC Educational Resources Information Center

    Sachdeva, Darshan

    The multivariate analog of Hays omega-squared for estimating the strength of the relationship in the multivariate analysis of variance has been proposed in this paper. The multivariate omega-squared is obtained through the use of Wilks' lambda test criterion. Application of multivariate omega-squared to a numerical example has been provided so as…

  15. RF digital-to-analog converter

    DOEpatents

    Conway, P.H.; Yu, D.U.L.

    1995-02-28

    A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

  16. Dopaminergic activity of four analogs of butaclamol.

    PubMed

    Collu, R; Bouvier, C; Basak, A; Dugas, H

    1985-12-01

    The displacing potency of four analogs of the neuroleptic drug butaclamol were evaluated using dog striatal tissue and [3H]-Spiroperidol as ligand. Although significantly less powerful than the parent compound, two of them (N-isobutyl butaclamol equatorial; N-methyl butaclamol equatorial) could be used for dopaminergic receptor studies.

  17. Optical folding-flash analog-to-digital converter with analog encoding.

    PubMed

    Jalali, B; Xie, Y M

    1995-09-15

    We describe an optically assisted folding-flash analog-to-digital converter. The periodic transfer function of the Mach-Zehnder interferometer is used to perform analog folding on the electronic signal to be quantized. A novel analog encoding scheme for efficient generation of gray code digital data is proposed. The new encoding scheme eliminates the requirement for interferometers with ultralow V(pi), which, so far, has hindered the development of such systems. The encoding concept is experimentally demonstrated through the use of LiNbO(3) modulators.

  18. Visual determination of differential renal function

    SciTech Connect

    Kipper, M.S.; Witztum, K.F.; Taylor, A. Jr.

    1986-05-01

    Forty patients (43 studies) referred for determination of differential renal function were imaged 24 hours after intravenous administration of Tc-99m-2, 3 DMSA. Visual assessment of relative renal uptake was estimated independently by three observers at three different hospitals from analog images on standard x-ray film. The results were compared with the relative DMSA uptake obtained by summing counts in computer-assisted regions of interest placed over each kidney. There was excellent correlation between the visual estimates of each observer and the computer-generated values (r = 0.98, 0.96, and 0.98, respectively). If a computer is not available, good visual estimates of differential uptake still may be obtained when static imaging agents such as DMSA are administered.

  19. The role of causal models in analogical inference.

    PubMed

    Lee, Hee Seung; Holyoak, Keith J

    2008-09-01

    Computational models of analogy have assumed that the strength of an inductive inference about the target is based directly on similarity of the analogs and in particular on shared higher order relations. In contrast, work in philosophy of science suggests that analogical inference is also guided by causal models of the source and target. In 3 experiments, the authors explored the possibility that people may use causal models to assess the strength of analogical inferences. Experiments 1-2 showed that reducing analogical overlap by eliminating a shared causal relation (a preventive cause present in the source) from the target increased inductive strength even though it decreased similarity of the analogs. These findings were extended in Experiment 3 to cross-domain analogical inferences based on correspondences between higher order causal relations. Analogical inference appears to be mediated by building and then running a causal model. The implications of the present findings for theories of both analogy and causal inference are discussed.

  20. How the creative use of analogies can shape medical practice.

    PubMed

    Prasad, G V Ramesh

    2015-06-01

    Analogical reasoning is central to medical progress, and is either creative or conservative. According to Hofmann et al., conservative analogy relates concepts from old technology to new technologies with emphasis on preservation of comprehension and conduct. Creative analogy however brings new understanding to new technology, brings similarities existing in the source domain to a target domain where they previously had no bearing, and imports something entirely different from the content of the analogy itself. I defend the claim that while conservative analogies are useful by virtue of being comfortable to use from familiarity and experience, and are more easily accepted by society, they only lead to incremental advances in medicine. However, creative analogies are more exciting and productive because they generate previously unexpected associations across widely separated domains, emphasize relations over physical similarities, and structure over superficiality. I use kidney transplantation and anti-rejection medication development as an exemplar of analogical reasoning used to improve medical practice. Anti-rejection medication has not helped highly sensitized patients because of their propensity to rejecting most organs. I outline how conservative analogical reasoning led to anti-rejection medication development, but creative analogical reasoning helped highly sensitized and blood type incompatible patients through domino transplants, by which they obtain a kidney to which they are not sensitized. Creative analogical reasoning is more likely than conservative analogical reasoning to lead to revolutionary progress. While these analogies overlap and creative analogies eventually become conservative, progress is best facilitated by combining conservative and creative analogical reasoning.

  1. Cortical Visual Impairment

    MedlinePlus

    ... Frequently Asked Questions Español Condiciones Chinese Conditions Cortical Visual Impairment En Español Read in Chinese What is cortical visual impairment? Cortical visual impairment (CVI) is a decreased ...

  2. Visual prediction and perceptual expertise

    PubMed Central

    Cheung, Olivia S.; Bar, Moshe

    2012-01-01

    Making accurate predictions about what may happen in the environment requires analogies between perceptual input and associations in memory. These elements of predictions are based on cortical representations, but little is known about how these processes can be enhanced by experience and training. On the other hand, studies on perceptual expertise have revealed that the acquisition of expertise leads to strengthened associative processing among features or objects, suggesting that predictions and expertise may be tightly connected. Here we review the behavioral and neural findings regarding the mechanisms involving prediction and expert processing, and highlight important possible overlaps between them. Future investigation should examine the relations among perception, memory and prediction skills as a function of expertise. The knowledge gained by this line of research will have implications for visual cognition research, and will advance our understanding of how the human brain can improve its ability to predict by learning from experience. PMID:22123523

  3. Beyond Visual Communication Technology.

    ERIC Educational Resources Information Center

    Bell, Thomas P.

    1993-01-01

    Discusses various aspects of visual communication--light, semiotics, codes, photography, typography, and visual literacy--within the context of the communications technology area of technology education. (SK)

  4. Multilateral Research Opportunities in Ground Analogs

    NASA Technical Reports Server (NTRS)

    Corbin, Barbara J.

    2015-01-01

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

  5. Not all analogies are created equal: Associative and categorical analogy processing following brain damage

    PubMed Central

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

    2012-01-01

    Current research on analogy processing assumes that different conceptual relations are treated similarly. However, just as words and concepts are related in distinct ways, different kinds of analogies may employ distinct types of relationships. An important distinction in how words are related is the difference between associative (dog-bone) and categorical (dog-cat) relations. To test the hypothesis that analogical mapping of different types of relations would have different neural instantiations, we tested patients with left and right hemisphere lesions on their ability to understand two types of analogies, ones expressing an associative relationship and others expressing a categorical relationship. Voxel-based lesion-symptom mapping (VLSM) and behavioral analyses revealed that associative analogies relied on a large left-lateralized language network while categorical analogies relied on both left and right hemispheres. The verbal nature of the task could account for the left hemisphere findings. We argue that categorical relations additionally rely on the right hemisphere because they are more difficult, abstract, and fragile; and contain more distant relationships. PMID:22402184

  6. Design of potent, proteolytically stable oxyntomodulin analogs

    PubMed Central

    Muppidi, Avinash; Zou, Huafei; Yang, Peng Yu; Chao, Elizabeth; Sherwood, Lance; Nunez, Vanessa; Woods, Ashley

    2016-01-01

    Incretin-based peptides are effective therapeutics for treating type 2 diabetes mellitus (T2DM). Oxyntomodulin (OXM), a dual agonist of GLP-1R and GCGR, has shown superior weight loss and glucose lowering effects, compared to single GLP-1R agonists. To overcome the short half-life and rapid renal clearance of OXM, which limit its therapeutic potential, both lipid and PEG modified OXM analogs have been reported. However, these approaches often result in reduced potency or PEG-associated toxicity. Herein we report a new class of cross-linked OXM analogs that show increased plasma stability and higher potency in activating both GLP-1R and GCGR. Moreover, the extended in vivo half-life results in superior anti-hyperglycemic activity in mice compared to the wild-type OXM. PMID:26727558

  7. Optimal neural computations require analog processors

    SciTech Connect

    Beiu, V.

    1998-12-31

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

  8. Terrestrial analogs of the hellespontus dunes, Mars

    USGS Publications Warehouse

    Breed, C.S.

    1977-01-01

    Geomorphic features in the Hellespontus region, Mars, were compared with dunes of the crescentic ridge type in numerous terrestrial sand seas quantitatively by dimensional analysis of dune lengths, widths, and wavelengths. Mean values for the Hellespontus dunes are close to mean values derived from measurements of all sampled terrestrial sand seas. Terrestrial analogs of form and areal distribution of the Hellespontus dunes are shown by comparison of scale ratios derived from the measurements. Dunes of similar form occur in South West Africa, in Pakistan, in the southeastern Arabian peninsula, in the Sahara, in eastern USSR and northern China, and in western North America. Terrestrial analogs closest to form and areal distribution of the Hellespontus dunes are in the Kara Kum Desert, Turkmen SSR, and in the Ala Shan (Gobi) Desert, China. ?? 1977.

  9. Observing spin optodynamical analog of cavity optomechanics

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

    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. Submarine Analogs to Venusian Pancake Domes

    NASA Technical Reports Server (NTRS)

    Bridges, Nathan T.

    1995-01-01

    The morphology and dimensions of the large diameter, steep-sided, flat-topped "pancake domes" on Venus make them unlike any type of terrestrial subaerial volcano. Comparisons between images of Hawaiian seamounts and pancake domes show similarities in shapes and secondary features. The morphometry of pancake domes is closer to that of Pacific seamounts than subaerial lava domes. Considering both morphology and morphometry, seamounts seem a better analog to the pancake domes. The control of volatile exsolution by pressure on Venus and the seafloor can cause lavas to have similar viscosities and densities, although the latter will be counteracted by high buoyancy underwater. However, analogous effects of the Venusian and seafloor alone are probably not sufficient to produce similar volcanoes. Rather, Venusian lavas of various compositions may behave like basalt on the seafloor if appropriate rates and modes of extrusion and planetary thermal structure are also considered.

  11. The optical analogy for vector fields

    NASA Technical Reports Server (NTRS)

    Parker, E. N. (Editor)

    1991-01-01

    This paper develops the optical analogy for a general vector field. The optical analogy allows the examination of certain aspects of a vector field that are not otherwise readily accessible. In particular, in the cases of a stationary Eulerian flow v of an ideal fluid and a magnetostatic field B, the vectors v and B have surface loci in common with their curls. The intrinsic discontinuities around local maxima in absolute values of v and B take the form of vortex sheets and current sheets, respectively, the former playing a fundamental role in the development of hydrodyamic turbulence and the latter playing a major role in heating the X-ray coronas of stars and galaxies.

  12. Survey of Evaluated Isobaric Analog States

    SciTech Connect

    MacCormick, M.

    2014-06-15

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

  13. Analog measurement of scattered optical fluctuations

    NASA Astrophysics Data System (ADS)

    Smith, P. R.; Green, D. A.

    1995-12-01

    A statistical model that describes the analog measurement of a fluctuating light intensity that arises from a non-Gaussian scattering process is developed. The higher-order statistical moments are derived for a p-i-n diode receiver model and gamma-distributed intensity fluctuations. Criteria for the accurate measurement of the scattering fluctuations are found, and these are used to analyze data derived from an on-line scatterometer system. Implications for future on-line measurement technology are discussed.

  14. Transition State Analog Inhibitors for Esterases.

    DTIC Science & Technology

    1983-06-02

    advanced about 1970, it has led to the synthesis of powerful reversible Inhibitors for a number of enzymes. More recently, transition state analog theory...to inactivate It. Organophosphate anticholinesterases are a classic example; many of the more recent examples allow the enzyme to generate a strong...could be utilized to explore such mechanistic questions. A second more practical goal was to prepare anticholinesterases of novel structure and

  15. Analog Fiber Optic Recirculating Delay Line.

    DTIC Science & Technology

    1987-03-31

    signal is input through a BNC type connector and a corresponding optical analog signal is output via a single mode optical fiber. The transmitter...second functional transmitter subdivision. The stripline fix- ture board provides an impedance matching stripline from a BNC input connector to the RF...drive signal input pin of the laser hybrid. Other socket pins on this circuit board provide for the proper routing of sensor outputs to the

  16. Biomedical sensor design using analog compressed sensing

    NASA Astrophysics Data System (ADS)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

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

  17. CCD Analog Programmable Microprocessor (APUP) Study

    DTIC Science & Technology

    1980-08-01

    failing module. Furthermore, the analog nature of charge- coupled devices (CCD’s) gives the prospect of a small-area, low-power, cost-effective...category, the data to be processed occur naturally in serial form and with storage times short enough that this category is a close match for CCD-based...future digital processors. Nonetheless, its pipeline nature might make it more suitable for a CCD type of implementation. The envelope detection block is

  18. Synthesis and biological evaluation of platensimycin analogs

    SciTech Connect

    Shen, Hong C.; Ding, Fa-Xiang; Singh, Sheo B.; Parthasarathy, Gopalakrishnan; Soisson, Stephen M.; Ha, Sookhee N.; Chen, Xun; Kodali, Srinivas; Wang, Jun; Dorso, Karen; Tata, James R.; Hammond, Milton L.; MacCoss, Malcolm; Colletti, Steven L.

    2009-07-23

    Platensimycin (1) displays antibacterial activity due to its inhibition of the elongation condensing enzyme (FabF), a novel mode of action that could potentially lead to a breakthrough in developing a new generation of antibiotics. The medicinal chemistry efforts were focused on the modification of the enone moiety of platensimycin and several analogs showed significant activity against FabF and possess antibacterial activity.

  19. Antimicrobial Activity of Novel Furanonaphthoquinone Analogs

    PubMed Central

    Nagata, Kumiko; Hirai, Kei-Ichi; Koyama, Junko; Wada, Yasunao; Tamura, Toshihide

    1998-01-01

    Analogs of furanonaphthoquinone (FNQ) from Tecoma ipe Mart had MICs ranging from 1.56 to 25 μg/ml against gram-positive bacteria. FNQ showed significantly lower MICs against methicillin-resistant Staphylococcus aureus than against methicillin-sensitive S. aureus. FNQ inhibited Helicobacter pylori with an MIC of 0.1 μg/ml. Fungi, including pathogenic species, were sensitive to FNQ with MICs similar to those of amphotericin B. PMID:9517956

  20. The 2012 Moon and Mars Analog Mission

    NASA Technical Reports Server (NTRS)

    Graham, Lee

    2014-01-01

    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. Optical Oversampled Analog-to-Digital Conversion

    DTIC Science & Technology

    1992-06-29

    Introduction 1 1.1 Background and Motivation........................... 2 1.1.1 Nyquist Rate Conversion........................ 3 1.1.2 Optical A/ D ...processor [9] was used with the electronic analog input signal driving an optical beam deflector . This method of optical A/ D conversion was limited...implement an optical oversampled A/ D converter. From the theoretical development in Chapter 2 , there are two principal functions which require optical

  2. Magnetic Analog Random-Access Memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R.; Wu, Jiin-Chuan; Stadler, Henry L.

    1991-01-01

    Proposed integrated, solid-state, analog random-access memory base on principle of magnetic writing and magnetoresistive reading. Current in writing conductor magnetizes storage layer. Remanent magnetization in storage layer penetrates readout layer and detected by magnetoresistive effect or Hall effect. Memory cells are part of integrated circuit including associated reading and writing transistors. Intended to provide high storage density and rapid access, nonvolatile, consumes little power, and relatively invulnerable to ionizing radiation.

  3. Total synthesis of neopeltolide and analogs

    PubMed Central

    Cui, Yubo; Tu, Wangyang; Floreancig, Paul E.

    2010-01-01

    Neopeltolide, a potent cytotoxin from a Carribean sponge, was synthesized through a brief sequence that highlights the use of ethers as oxocarbenium ion precursors. Other key steps include an acid-mediated etherification and sequence that features a Sonogashira reaction, an intramolecular alkyne hydrosilylation reaction, and a Tamao oxidation. The alkene that is required for the oxidative cyclization can be hydrogenated to provide access to the natural product or an epimer, or can be epoxidized or dihydroxylated to form polar analogs. PMID:20697460

  4. On estimation of uncertainties in analog measurements

    SciTech Connect

    Adibi, M.M. ); Stovall, J.P. )

    1990-11-01

    Computer control of power systems require evaluation of uncertainties in analog measurements and their reduction to a level that allows satisfactory control. In this paper a range of measurements is obtained from a substation to span peak- and light-load conditions and to include bus voltages, phase angles and line flows. Then the redundancies in measurements are used to formulate several functions relating these measurements with their attending errors. Minimization of these functions have yielded the required corrective coefficients.

  5. Subduction initiation and Obduction: insights from analog models

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    Subduction initiation and obduction are two poorly constrained geodynamic processes which are interrelated in a number of natural settings. Subduction initiation can be viewed as the result of a regional-scale change in plate convergence partitioning between the set of existing subduction (and collision or obduction) zones worldwide. Intraoceanic subduction initiation may also ultimately lead to obduction of dense oceanic "ophiolites" atop light continental plates. A classic example is the short-lived Peri-Arabic obduction, which took place along thousands of km almost synchronously (within ~5-10 myr), from Turkey to Oman, while the subduction zone beneath Eurasia became temporarily jammed. We herein present analog models designed to study both processes and more specifically (1) subduction initiation through the partitioning of deformation between two convergent zones (a preexisting and a potential one) and, as a consequence, (2) the possible development of obduction, which has so far never been modeled. These models explore the mechanisms of subduction initiation and obduction and test various triggering hypotheses (i.e., plate acceleration, slab crossing the 660 km discontinuity, ridge subduction; Agard et al., 2007). The experimental setup comprises an upper mantle modelled as a low-viscosity transparent Newtonian glucose syrup filling a rigid Plexiglas tank and high-viscosity silicone plates. Convergence is simulated by pushing on a piston at one end of the model with plate tectonics like velocities (1-10 cm/yr) onto (i) a continental margin, (ii) a weakness zone with variable resistance and dip (W), (iii) an oceanic plate - with or without a spreading ridge, (iv) a subduction zone (S) dipping away from the piston and (v) an upper active continental margin, below which the oceanic plate is being subducted at the start of the experiment (as for the Oman case). Several configurations were tested over thirty-five parametric experiments. Special emphasis was

  6. Targeting thyroid diseases with TSH receptor analogs.

    PubMed

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

    2013-12-01

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

  7. Clinical utility of insulin and insulin analogs

    PubMed Central

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

    2013-01-01

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

  8. Multiphoton excitation of fluorescent DNA base analogs.

    PubMed

    Katilius, Evaldas; Woodbury, Neal W

    2006-01-01

    Multiphoton excitation was used to investigate properties of the fluorescent DNA base analogs, 2-aminopurine (2AP) and 6-methylisoxanthopterin (6MI). 2-aminopurine, a fluorescent analog of adenine, was excited by three-photon absorption. Fluorescence correlation measurements were attempted to evaluate the feasibility of using three-photon excitation of 2AP for DNA-protein interaction studies. However, high excitation power and long integration times needed to acquire high signal-to-noise fluorescence correlation curves render three-photon excitation FCS of 2AP not very useful for studying DNA base dynamics. The fluorescence properties of 6-methylisoxanthopterin, a guanine analog, were investigated using two-photon excitation. The two-photon absorption cross-section of 6MI was estimated to be about 2.5 x 10(-50) cm(4)s (2.5 GM units) at 700 nm. The two-photon excitation spectrum was measured in the spectral region from 700 to 780 nm; in this region the shape of the two-photon excitation spectrum is very similar to the shape of single-photon excitation spectrum in the near-UV spectral region. Two-photon excitation of 6MI is suitable for fluorescence correlation measurements. Such measurements can be used to study DNA base dynamics and DNA-protein interactions over a broad range of time scales.

  9. Periglacial and glacial analogs for Martian landforms

    NASA Technical Reports Server (NTRS)

    Rossbacher, Lisa A.

    1992-01-01

    The list of useful terrestrial analogs for Martian landforms has been expanded to include: features developed by desiccation processes; catastrophic flood features associated with boulder-sized materials; and sorted ground developed at a density boundary. Quantitative analytical techniques developed for physical geography have been adapted and applied to planetary studies, including: quantification of the patterns of polygonally fractured ground to describe pattern randomness independent of pattern size, with possible correlation to the mechanism of origin and quantification of the relative area of a geomorphic feature or region in comparison to planetary scale. Information about Martian geomorphology studied in this project was presented at professional meetings world-wide, at seven colleges and universities, in two interactive televised courses, and as part of two books. Overall, this project has expanded the understanding of the range of terrestrial analogs for Martian landforms, including identifying several new analogs. The processes that created these terrestrial features are characterized by both cold temperatures and low humidity, and therefore both freeze-thaw and desiccation processes are important. All these results support the conclusion that water has played a significant role in the geomorphic history of Mars.

  10. Theory of analogous force on number sets

    NASA Astrophysics Data System (ADS)

    Canessa, Enrique

    2003-10-01

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

  11. Snowflake Visualization

    NASA Astrophysics Data System (ADS)

    Bliven, L. F.; Kucera, P. A.; Rodriguez, P.

    2010-12-01

    NASA Snowflake Video Imagers (SVIs) enable snowflake visualization at diverse field sites. The natural variability of frozen precipitation is a complicating factor for remote sensing retrievals in high latitude regions. Particle classification is important for understanding snow/ice physics, remote sensing polarimetry, bulk radiative properties, surface emissivity, and ultimately, precipitation rates and accumulations. Yet intermittent storms, low temperatures, high winds, remote locations and complex terrain can impede us from observing falling snow in situ. SVI hardware and software have some special features. The standard camera and optics yield 8-bit gray-scale images with resolution of 0.05 x 0.1 mm, at 60 frames per second. Gray-scale images are highly desirable because they display contrast that aids particle classification. Black and white (1-bit) systems display no contrast, so there is less information to recognize particle types, which is particularly burdensome for aggregates. Data are analyzed at one-minute intervals using NASA's Precipitation Link Software that produces (a) Particle Catalogs and (b) Particle Size Distributions (PSDs). SVIs can operate nearly continuously for long periods (e.g., an entire winter season), so natural variability can be documented. Let’s summarize results from field studies this past winter and review some recent SVI enhancements. During the winter of 2009-2010, SVIs were deployed at two sites. One SVI supported weather observations during the 2010 Winter Olympics and Paralympics. It was located close to the summit (Roundhouse) of Whistler Mountain, near the town of Whistler, British Columbia, Canada. In addition, two SVIs were located at the King City Weather Radar Station (WKR) near Toronto, Ontario, Canada. Access was prohibited to the SVI on Whistler Mountain during the Olympics due to security concerns. So to meet the schedule for daily data products, we operated the SVI by remote control. We also upgraded the

  12. Spelling: A Visual Skill.

    ERIC Educational Resources Information Center

    Hendrickson, Homer

    1988-01-01

    Spelling problems arise due to problems with form discrimination and inadequate visualization. A child's sequence of visual development involves learning motor control and coordination, with vision directing and monitoring the movements; learning visual comparison of size, shape, directionality, and solidity; developing visual memory or recall;…

  13. Glucagon-like Peptide-1 (GLP-1) Analogs: Recent Advances, New Possibilities, and Therapeutic Implications

    PubMed Central

    2015-01-01

    Glucagon-like peptide-1 (GLP-1) is an incretin that plays important physiological roles in glucose homeostasis. Produced from intestine upon food intake, it stimulates insulin secretion and keeps pancreatic β-cells healthy and proliferating. Because of these beneficial effects, it has attracted a great deal of attention in the past decade, and an entirely new line of diabetic therapeutics has emerged based on the peptide. In addition to the therapeutic applications, GLP-1 analogs have demonstrated a potential in molecular imaging of pancreatic β-cells; this may be useful in early detection of the disease and evaluation of therapeutic interventions, including islet transplantation. In this Perspective, we focus on GLP-1 analogs for their studies on improvement of biological activities, enhancement of metabolic stability, investigation of receptor interaction, and visualization of the pancreatic islets. PMID:25349901

  14. When Reasoning Modifies Memory: Schematic Assimilation Triggered by Analogical Mapping

    ERIC Educational Resources Information Center

    Vendetti, Michael S.; Wu, Aaron; Rowshanshad, Ebi; Knowlton, Barbara J.; Holyoak, Keith J.

    2014-01-01

    Analogical mapping highlights shared relations that link 2 situations, potentially at the expense of information that does not fit the dominant pattern of correspondences. To investigate whether analogical mapping can alter subsequent recognition memory for features of a source analog, we performed 2 experiments with 4-term proportional analogies…

  15. Can Pupils Use Taught Analogies for Electric Current?

    ERIC Educational Resources Information Center

    Black, David; Solomon, Joan

    1987-01-01

    Discusses the use of analogies and models for teaching about electric current. Reports on a study in which one group of students used analogies to learn about electric current and one did not. Results indicate that, in this case, analogies did not play a significant role in student understanding. (TW)

  16. The Role of Causal Models in Analogical Inference

    ERIC Educational Resources Information Center

    Lee, Hee Seung; Holyoak, Keith J.

    2008-01-01

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

  17. Analog Microcontroller Model for an Energy Harvesting Round Counter

    DTIC Science & Technology

    2012-07-01

    Technical Report ARWSB-TR-12012 Analog Microcontroller Model for an Energy Harvesting Round Counter Sara...YYYY) 06-06-2012 2. REPORT TYPE FINAL 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Analog Microcontroller Model for an Energy ... Microcontroller The greatest energy requirements of the round counter circuitry are associated with the Microchip PIC12LF1822 microcontroller [4]. An analog

  18. Investigating and Theorizing Discourse during Analogy Writing in Chemistry

    ERIC Educational Resources Information Center

    Bellocchi, Alberto; Ritchie, Stephen M.

    2011-01-01

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

  19. Interactive Optical Disc Systems: Part 1: Analog Storage.

    ERIC Educational Resources Information Center

    Hessler, David W.

    1984-01-01

    Details distinction between digital and analog data, advantages of analog storage, and optical disc use to store analog data. Configuration and potential of three levels of laser disc systems are explained. Selection of display devices for use with laser disc systems and accessing audio data are addressed. (Continued in next issue.) (EJS)

  20. Modern Communication: Exploring Physiological Transmission through Tech-Savvy Analogies

    ERIC Educational Resources Information Center

    Hollabaugh, Christopher R.; Milanick, Mark A.

    2014-01-01

    Analogies are often helpful for students to grasp key physiological concepts; sometimes the technical jargon makes the concept seem more complex than it actually is. In this article the authors provide several analogies for information transfer processes that sometimes confuse students. For an analogy to be useful, of course, it needs to be…

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

    ERIC Educational Resources Information Center

    Thomas, Leela

    2008-01-01

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

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

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  3. Functional DNA: Teaching Infinite Series through Genetic Analogy

    ERIC Educational Resources Information Center

    Kowalski, R. Travis

    2011-01-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  5. Administration of Biosimilar Insulin Analogs: Role of Devices.

    PubMed

    Heinemann, Lutz; Fritz, Ingo; Khatami, Hootan; Edelman, Steven V

    2017-02-01

    With the expiration of patent protection for several originator insulin analog molecules, the availability of insulin analog copies is set to increase. Many regulatory authorities have developed, and continue to refine, guidelines for the approval of biosimilar insulin analogs. Aspects such as the structure, pharmacokinetics and pharmacodynamics, efficacy, safety, and immunogenicity of biosimilar insulin analogs are extensively addressed in these guidelines, but how the biosimilar insulin analog is administered to people with diabetes is not usually a topic. The aim of this article is to highlight that the delivery device-drug combination is of particular importance. Regulatory, legal, and practical aspects of the delivery device, be it a syringe, pen, or pump, have to be considered in the context of biosimilar insulin analogs. Although the safety and efficacy of biosimilar insulin analogs per se are of primary importance for physicians and people with diabetes, functions and features of the devices used for administration also require attention from a practical point of view. Unfortunately, although there are several clinical studies investigating the technical aspects of and patient preference for the originator insulin analog pens, there are currently very little published data for nonoriginator or biosimilar insulin analog pens. In addition, it is not known if it is safe to assume that a biosimilar insulin analog cartridge is compatible with an existing originator insulin analog pen. We believe that there is a need for more discussion on the role of devices for administration of biosimilar insulin analogs.

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

    PubMed

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

    2015-08-05

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

  7. Analogy Use in Eighth-Grade Mathematics Classrooms

    ERIC Educational Resources Information Center

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

    2004-01-01

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

  8. Comparison of Three Methods for Improving Verbal Analogies Solution.

    ERIC Educational Resources Information Center

    Loewenthal, Gloria G.; Pons, Manuel M.

    1987-01-01

    Investigates the relationship between analogical reasoning and academic learning. Results show that efforts to improve academic achievement through training in analogical thinking are based on the correct assumption that analogical thinking can be trained and that various methods of training are effective in this regard. (MS)

  9. Historical Shifts in the Use of Analogy in Science.

    ERIC Educational Resources Information Center

    Gentner, Dedre; Jeziorski, Michael

    Analogy is widely considered to be an important mechanism of scientific thinking and a source of creative insight in theory development. In this paper the implicit constraints that determine analogical soundness are considered. It first examines the constraints that govern analogical reasoning as it is predicted today. The scientific uses of…

  10. Visualization of second order tensor fields and matrix data

    NASA Technical Reports Server (NTRS)

    Delmarcelle, Thierry; Hesselink, Lambertus

    1992-01-01

    We present a study of the visualization of 3-D second order tensor fields and matrix data. The general problem of visualizing unsymmetric real or complex Hermitian second order tensor fields can be reduced to the simultaneous visualization of a real and symmetric second order tensor field and a real vector field. As opposed to the discrete iconic techniques commonly used in multivariate data visualization, the emphasis is on exploiting the mathematical properties of tensor fields in order to facilitate their visualization and to produce a continuous representation of the data. We focus on interactively sensing and exploring real and symmetric second order tensor data by generalizing the vector notion of streamline to the tensor concept of hyperstreamline. We stress the importance of a structural analysis of the data field analogous to the techniques of vector field topology extraction in order to obtain a unique and objective representation of second order tensor fields.

  11. CMOS prototype for retinal prosthesis applications with analog processing

    NASA Astrophysics Data System (ADS)

    Castillo-Cabrera, G.; García-Lamont, J.; Reyes-Barranca, M. A.; Matsumoto-Kuwabara, Y.; Moreno-Cadenas, J. A.; Flores-Nava, L. M.

    2014-12-01

    A core architecture for analog processing, which emulates a retina's receptive field, is presented in this work. A model was partially implemented and built on CMOS standard technology through MOSIS. It considers that the receptive field is the basic unit for image processing in the visual system. That is why the design is concerned on a partial solution of receptive field properties in order to be adapted in the future as an aid to people with retinal diseases. A receptive field is represented by an array of 3×3 pixels. Each pixel carries out a process based on four main operations. This means that image processing is developed at pixel level. Operations involved are: (1) photo-transduction by photocurrent integration, (2) signal averaging from eight neighbouring pixels executed by a neu-NMOS (ν-NMOS) neuron, (3) signal average gradient between central pixel and the average value from the eight neighbouring pixels (this gradient is performed by a comparator) and finally (4) a pulse generator. Each one of these operations gives place to circuital blocks which were built on 0.5 μm CMOS technology.

  12. Self-folding polyhedra and analogies to biomolecular assembly

    NASA Astrophysics Data System (ADS)

    Pandey, Shivendra; Menon, Govind; Gracias, David

    2013-03-01

    We detail model studies aimed at uncovering design principles that govern the self-assembly of polyhedral structures from two-dimensional precursors using surface tension forces. For a given polyhedron, there are a very large number of two-dimensional precursor nets that can be utilized, and remarkably many of these will self-assemble but with varying yields. We uncovered design rules that suggest striking analogies to biomolecular assembly such as observed in proteins and viruses. For example our studies revealed that the compactness of two-dimensional nets determines the yield of self-folding polyhedra and that certain intermediates and pathways were preferred. Consequently, a search algorithm was implemented to screen the large numbers of nets (e.g. 2.3 million for the truncated octahedron) and find high-yielding precursors. This assembly process represents a model system that can be utilized to design and then visualize self-assembly processes. The model system, design rules and findings will be discussed.

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  14. Flow visualization experiments in a porous nozzle

    NASA Technical Reports Server (NTRS)

    Cielak, Z.; Kinney, R. B.; Perkins, H. C.

    1973-01-01

    An experimental approach is described for the study of nozzle flows with large wall-transpiration rates. Emphasizing a qualitative understanding of the flow, the technique uses the hydraulic analogy, whereby a compressible gas flow is simulated by a water flow having a free surface. For simplicity, the simulated gas flow is taken to be two-dimensional. A nozzle with porous walls in the throat region has been developed for use on a water table. A technique for visualizing the transpired fluid has also been devised. These are discussed, and preliminary results are presented which illustrate the success of the experimental approach.

  15. SSERVI Analog Regolith Simulant Testbed Facility

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  16. Scalable analog wavefront sensor with subpixel resolution

    NASA Astrophysics Data System (ADS)

    Wilcox, Michael

    2006-06-01

    Standard Shack-Hartman wavefront sensors use a CCD element to sample position and distortion of a target or guide star. Digital sampling of the element and transfer to a memory space for subsequent computation adds significant temporal delay, thus, limiting the spatial frequency and scalability of the system as a wavefront sensor. A new approach to sampling uses information processing principles in an insect compound eye. Analog circuitry eliminates digital sampling and extends the useful range of the system to control a deformable mirror and make a faster, more capable wavefront sensor.

  17. Soviet Space Stations as Analogs, Second Edition

    NASA Technical Reports Server (NTRS)

    Bluth, B. J.; Helppie, Martha

    1986-01-01

    The available literature that discusses the various aspects of the Soviet Salyut 6 and Salyut 7 space staions are examined as related to human productivity. The methodology for this analog was a search of unclassified literature. Additional information was obtained in interviews with the cosmonauts and some Soviet space personnel. Topics include: general layout and design of the spacecraft system; cosmonauts role in maintenance and repair; general layout and design of the Mir complex; effects of the environment on personnel; information and computer systems; organization systems; personality systems; and physical conditin of the cosmonaut.

  18. Analog/Digital System for Germanium Thermometer

    NASA Technical Reports Server (NTRS)

    Woodhouse, Christopher

    1988-01-01

    Electronic system containing analog and digital circuits makes high-precision, four-wire measurements of resistance of each germanium resistance thermometer (GRT) in array of devices, using alternating current (ac) of 1 micro-A. At end measurement interval, contents of negative register subtracted from positive one, resulting in very-narrow-band synchronous demodulation of carrier wave and suppression of out-of-band noise. Microprocessor free to perform other duties after measurement complete. Useful in noisy terrestrial environments encountered in factories.

  19. Solid-state-based analog of optomechanics

    DOE PAGES

    Naumann, Nicolas L.; Droenner, Leon; Carmele, Alexander; ...

    2016-09-01

    In this study, we investigate a semiconductor quantum dot as a microscopic analog of a basic optomechanical setup. We show that optomechanical features can be reproduced by the solid-state platform, arising from parallels of the underlying interaction processes, which in the optomechanical case is the radiation pressure coupling and in the semiconductor case the electron–phonon coupling. We discuss bistabilities, lasing, and phonon damping, and recover the same qualitative behaviors for the semiconductor and the optomechanical cases expected for low driving strengths. However, in contrast to the optomechanical case, distinct signatures of higher order processes arise in the semiconductor model.

  20. Mars-Analog Evaporite Experiment: Initial Results

    NASA Technical Reports Server (NTRS)

    Moore, J. M.; Bullock, M. A.; Sharp, T.G.; Quinn, R.

    2005-01-01

    This research is part of a multiyear experimental investigation to understand the nature and evolution brines and evaporates on Mars. The spectacular discoveries of the MER rovers, particularly those of Opportunity at Meridiani, both illustrate the relevance, as well as guide the future direction, of this work. Here we report the initial results from our just-completed and tested evaporites apparatus, using a synthetic brine analog to our brine experiment simulating a modern Mars environment in which the brine was subjected to rapid evaporation under modern Martian conditions. Additional information is included in the original extended abstract.

  1. Analogy among microfluidics, micromechanics, and microelectronics.

    PubMed

    Li, Sheng-Shian; Cheng, Chao-Min

    2013-10-07

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

  2. A bilateral frontoparietal network underlies visuospatial analogical reasoning.

    PubMed

    Watson, Christine E; Chatterjee, Anjan

    2012-02-01

    Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies.

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

    PubMed

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

    2010-10-01

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

  4. Declarative Visualization Queries

    NASA Astrophysics Data System (ADS)

    Pinheiro da Silva, P.; Del Rio, N.; Leptoukh, G. G.

    2011-12-01

    In an ideal interaction with machines, scientists may prefer to write declarative queries saying "what" they want from a machine than to write code stating "how" the machine is going to address the user request. For example, in relational database, users have long relied on specifying queries using Structured Query Language (SQL), a declarative language to request data results from a database management system. In the context of visualizations, we see that users are still writing code based on complex visualization toolkit APIs. With the goal of improving the scientists' experience of using visualization technology, we have applied this query-answering pattern to a visualization setting, where scientists specify what visualizations they want generated using a declarative SQL-like notation. A knowledge enhanced management system ingests the query and knows the following: (1) know how to translate the query into visualization pipelines; and (2) how to execute the visualization pipelines to generate the requested visualization. We define visualization queries as declarative requests for visualizations specified in an SQL like language. Visualization queries specify what category of visualization to generate (e.g., volumes, contours, surfaces) as well as associated display attributes (e.g., color and opacity), without any regards for implementation, thus allowing scientists to remain partially unaware of a wide range of visualization toolkit (e.g., Generic Mapping Tools and Visualization Toolkit) specific implementation details. Implementation details are only a concern for our knowledge-based visualization management system, which uses both the information specified in the query and knowledge about visualization toolkit functions to construct visualization pipelines. Knowledge about the use of visualization toolkits includes what data formats the toolkit operates on, what formats they output, and what views they can generate. Visualization knowledge, which is not

  5. Dis/Assembling Schizophrenia on YouTube: Theorizing an Analog Body in a Virtual Sphere.

    PubMed

    Fletcher, Erica Hua

    2016-09-01

    As visual technologies become increasingly networked online, websites like YouTube provide a space to share vlogs (video blogs) online, suggest related content for viewers, and help in/form virtual communities, including those of mental illness. Within this space, vlogs of schizophrenia and comments generated about them by other users can represent transitional, dialogical states of illness that speak back to the analog body and affect a body's way of being in the world. Moreover, as vlogs create resistance against static definitions of schizophrenia, they may foster a creativity, experimentation, and inventiveness that transforms understandings of schizophrenia within the sciences and humanities.

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

    PubMed

    Wiland, E

    2000-12-01

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

  7. The importance of explicitly mapping instructional analogies in science education

    NASA Astrophysics Data System (ADS)

    Asay, Loretta Johnson

    Analogies are ubiquitous during instruction in science classrooms, yet research about the effectiveness of using analogies has produced mixed results. An aspect seldom studied is a model of instruction when using analogies. The few existing models for instruction with analogies have not often been examined quantitatively. The Teaching With Analogies (TWA) model (Glynn, 1991) is one of the models frequently cited in the variety of research about analogies. The TWA model outlines steps for instruction, including the step of explicitly mapping the features of the source to the target. An experimental study was conducted to examine the effects of explicitly mapping the features of the source and target in an analogy during computer-based instruction about electrical circuits. Explicit mapping was compared to no mapping and to a control with no analogy. Participants were ninth- and tenth-grade biology students who were each randomly assigned to one of three conditions (no analogy module, analogy module, or explicitly mapped analogy module) for computer-based instruction. Subjects took a pre-test before the instruction, which was used to assign them to a level of previous knowledge about electrical circuits for analysis of any differential effects. After the instruction modules, students took a post-test about electrical circuits. Two weeks later, they took a delayed post-test. No advantage was found for explicitly mapping the analogy. Learning patterns were the same, regardless of the type of instruction. Those who knew the least about electrical circuits, based on the pre-test, made the most gains. After the two-week delay, this group maintained the largest amount of their gain. Implications exist for science education classrooms, as analogy use should be based on research about effective practices. Further studies are suggested to foster the building of research-based models for classroom instruction with analogies.

  8. The Visual Analysis of Visual Metaphor.

    ERIC Educational Resources Information Center

    Dake, Dennis M.; Roberts, Brian

    This paper presents an approach to understanding visual metaphor which uses metaphoric analysis and comprehension by graphic and pictorial means. The perceptible qualities of shape, line, form, color, and texture, that make up the visual structure characteristic of any particular shape, configuration, or scene, are called physiognomic properties;…

  9. A Qualitative Analogy for Respiratory Mechanics

    ERIC Educational Resources Information Center

    Baptista, Vander

    2010-01-01

    The geometric configuration and mechanical properties of the integral elements of the respiratory system, as well as the modus operandi of the interacting parts in the ventilation process, comprise a hard-to-visualize system, making the mechanics of pulmonary ventilation a confusing topic for students and a difficult task for the teacher. To…

  10. Analog VLSI for active drag reduction

    NASA Astrophysics Data System (ADS)

    Gupta, Vidyabhusan

    In today's cost-conscious air transportation industry, fuel costs are a substantial economic concern. Drag reduction is an important way to increase fuel efficiency which reduces these costs. Even a 1% reduction in drag can translate into estimated savings of tens of millions of dollars in annual fuel costs. Fluid mechanicists believe that microscopic vortex pairs impinging on the surface play an important role in turbulent transport that may cause large skin friction drag. The microscopic nature and unpredictable appearance of these structures has limited practical approaches to their control. With the advent of micromachining technology providing the ability to build mechanical structures with microscopic dimensions, the tools finally exist with which to detect and control the vortex structures. These sensors and actuators require control circuitry between them in order to build a complete system. We propose an analog VLSI system that can process information along a surface in a moving fluid with the goal of controlling actuators to minimize the surface shear stress. We obtain the information from the surface by using microsensors which measure the surface shear stress. The actuators interact with the fluid by moving up and down in an attempt to diminish the impact of the drag-inducing structures in the fluid. We have designed the fabricated an analog control system. We have tested the system in several different experiments to verify its effectiveness in providing a control signal that energizes an actuator. We also have studied the methodology for a completely integrated wafer-scale system.

  11. Digital and analog gene circuits for biotechnology.

    PubMed

    Roquet, Nathaniel; Lu, Timothy K

    2014-05-01

    Biotechnology offers the promise of valuable chemical production via microbial processing of renewable and inexpensive substrates. Thus far, static metabolic engineering strategies have enabled this field to advance industrial applications. However, the industrial scaling of statically engineered microbes inevitably creates inefficiencies due to variable conditions present in large-scale microbial cultures. Synthetic gene circuits that dynamically sense and regulate different molecules can resolve this issue by enabling cells to continuously adapt to variable conditions. These circuits also have the potential to enable next-generation production programs capable of autonomous transitioning between steps in a bioprocess. Here, we review the design and application of two main classes of dynamic gene circuits, digital and analog, for biotechnology. Within the context of these classes, we also discuss the potential benefits of digital-analog interconversion, memory, and multi-signal integration. Though synthetic gene circuits have largely been applied for cellular computation to date, we envision that utilizing them in biotechnology will enhance the efficiency and scope of biochemical production with living cells.

  12. AFEII Analog Front End Board Design Specifications

    SciTech Connect

    Rubinov, Paul; /Fermilab

    2005-04-01

    This document describes the design of the 2nd iteration of the Analog Front End Board (AFEII), which has the function of receiving charge signals from the Central Fiber Tracker (CFT) and providing digital hit pattern and charge amplitude information from those charge signals. This second iteration is intended to address limitations of the current AFE (referred to as AFEI in this document). These limitations become increasingly deleterious to the performance of the Central Fiber Tracker as instantaneous luminosity increases. The limitations are inherent in the design of the key front end chips on the AFEI board (the SVXIIe and the SIFT) and the architecture of the board itself. The key limitations of the AFEI are: (1) SVX saturation; (2) Discriminator to analog readout cross talk; (3) Tick to tick pedestal variation; and (4) Channel to channel pedestal variation. The new version of the AFE board, AFEII, addresses these limitations by use of a new chip, the TriP-t and by architectural changes, while retaining the well understood and desirable features of the AFEI board.

  13. Metaphor and analogy in everyday problem solving.

    PubMed

    Keefer, Lucas A; Landau, Mark J

    2016-11-01

    Early accounts of problem solving focused on the ways people represent information directly related to target problems and possible solutions. Subsequent theory and research point to the role of peripheral influences such as heuristics and bodily states. We discuss how metaphor and analogy similarly influence stages of everyday problem solving: Both processes mentally map features of a target problem onto the structure of a relatively more familiar concept. When individuals apply this structure, they use a well-known concept as a framework for reasoning about real world problems and candidate solutions. Early studies found that analogy use helped people gain insight into novel problems. More recent research on metaphor goes further to show that activating mappings has subtle, sometimes surprising effects on judgment and reasoning in everyday problem solving. These findings highlight situations in which mappings can help or hinder efforts to solve problems. WIREs Cogn Sci 2016, 7:394-405. doi: 10.1002/wcs.1407 For further resources related to this article, please visit the WIREs website.

  14. Martian hillside gullies and icelandic analogs

    NASA Astrophysics Data System (ADS)

    Hartmann, William K.; Thorsteinsson, Thorsteinn; Sigurdsson, Freysteinn

    2003-04-01

    We report observations of Icelandic hillside gully systems that are near duplicates of gullies observed on high-latitude martian hillsides. The best Icelandic analogs involve basaltic talus slopes at the angle of repose, with gully formation by debris flows initiated by ground water saturation, and/or by drainage of water from upslope cliffs. We report not only the existence of Mars analog gullies, but also an erosional sequence of morphologic forms, found both on Mars and in Iceland. The observations support hypotheses calling for creation of martian gullies by aqueous processes. Issues remain whether the water in each case comes only from surficial sources, such as melting of ground ice or snow, or from underground sources such as aquifers that gain surface access in hillsides. Iceland has many examples of the former, but the latter mechanism is not ruled out. Our observations are consistent with the martian debris flow mechanism of F. Costard et al. (2001c, Science295, 110-113), except that classic debris flows begin at midslope more frequently than on Mars. From morphologic observations, we suggest that some martian hillside gully systems not only involve significant evolution by extended erosive activity, but gully formation may occur in episodes, and the time interval since the last episode is considerably less than the time interval needed to erase the gully through normal martian obliteration processes.

  15. Amygdalin analogs for the treatment of psoriasis.

    PubMed

    Perez, Juan J

    2013-05-01

    Psoriasis is one of the most prevalent immune-mediated illness worldwide. The disease can still only be managed rather than cured, so treatments are aimed at clearing skin lesions and preventing their recurrence. Several treatments are available depending on the extent of the psoriatic lesion. Among the topical treatments corticostereoids, vitamin D3 analogs and retinoids are commonly used. However, these treatments may have adverse effects in the long term. Conversely, systemic conventional treatments include immunosuppresors such as cyclosporin or methotrexate associated with high toxicity levels. Biologicals are alternative therapeutical agents introduced in the last 10 years. These include fusion proteins or monoclonal antibodies designed to inhibit the action of specific cytokines or to prevent T-lymphocyte activation. However, due to recent knowledge on the etiology of the disease, diverse new small molecules have appeared as promising alternatives for the treatment of psoriasis. Among them, inhibitors of JAK3, inhibitors of PDE 4 and amygdalin analogs. The latter are promising small molecules presently in preclinical studies which are the object of the present report.

  16. The gravitational analog of Faraday's induction law

    NASA Astrophysics Data System (ADS)

    Zile, Daniel; Overduin, James

    2015-04-01

    Michael Faraday, the discoverer of electromagnetic induction, was convinced that there must also be a gravitational analog of this law, and he carried out drop-tower experiments in 1849 to look for the electric current induced in a coil by changes in gravitational flux through the coil. This work, now little remembered, was in some ways the first investigation of what we would now call a unified-field theory. We revisit Faraday's experiments in the light of current knowledge and ask what might be learned if they were to be performed today. We then review the gravitational analog for Faraday's law that arises within the vector (or gravito-electromagnetic) approximation to Einstein's theory of general relativity in the weak-field, low-velocity limit. This law relates spinning masses and induced ``mass currents'' rather than spinning charges and electric currents, but is otherwise remarkably similar to its electromagnetic counterpart. The predicted effects are completely unobservable in everyday settings like those envisioned by Faraday, but are thought to be relevant in astrophysical contexts like the accretion disks around collapsed stars, thus bearing out Faraday's remarkable intuition. Undergraduate student.

  17. Photonic analog-to-digital converters

    NASA Astrophysics Data System (ADS)

    Valley, George C.

    2007-03-01

    This paper reviews over 30 years of work on photonic analog-to-digital converters. The review is limited to systems in which the input is a radio-frequency (RF) signal in the electronic domain and the output is a digital version of that signal also in the electronic domain, and thus the review excludes photonic systems directed towards digitizing images or optical communication signals. The state of the art in electronic ADCs, basic properties of ADCs and properties of analog optical links, which are found in many photonic ADCs, are reviewed as background information for understanding photonic ADCs. Then four classes of photonic ADCs are reviewed: 1) photonic assisted ADC in which a photonic device is added to an electronic ADC to improve performance, 2) photonic sampling and electronic quantizing ADC, 3) electronic sampling and photonic quantizing ADC, and 4) photonic sampling and quantizing ADC. It is noted, however, that all 4 classes of “photonic ADC” require some electronic sampling and quantization. After reviewing all known photonic ADCs in the four classes, the review concludes with a discussion of the potential for photonic ADCs in the future.

  18. Menaquinone Analogs Inhibit Growth of Bacterial Pathogens

    PubMed Central

    Merriman, Joseph A.; Salgado-Pabón, Wilmara; Mueller, Elizabeth A.; Spaulding, Adam R.; Vu, Bao G.; Chuang-Smith, Olivia N.; Kohler, Petra L.; Kirby, John R.

    2013-01-01

    Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents. PMID:23959313

  19. Menaquinone analogs inhibit growth of bacterial pathogens.

    PubMed

    Schlievert, Patrick M; Merriman, Joseph A; Salgado-Pabón, Wilmara; Mueller, Elizabeth A; Spaulding, Adam R; Vu, Bao G; Chuang-Smith, Olivia N; Kohler, Petra L; Kirby, John R

    2013-11-01

    Gram-positive bacteria cause serious human illnesses through combinations of cell surface and secreted virulence factors. We initiated studies with four of these organisms to develop novel topical antibacterial agents that interfere with growth and exotoxin production, focusing on menaquinone analogs. Menadione, 1,4-naphthoquinone, and coenzymes Q1 to Q3 but not menaquinone, phylloquinone, or coenzyme Q10 inhibited the growth and to a greater extent exotoxin production of Staphylococcus aureus, Bacillus anthracis, Streptococcus pyogenes, and Streptococcus agalactiae at concentrations of 10 to 200 μg/ml. Coenzyme Q1 reduced the ability of S. aureus to cause toxic shock syndrome in a rabbit model, inhibited the growth of four Gram-negative bacteria, and synergized with another antimicrobial agent, glycerol monolaurate, to inhibit S. aureus growth. The staphylococcal two-component system SrrA/B was shown to be an antibacterial target of coenzyme Q1. We hypothesize that menaquinone analogs both induce toxic reactive oxygen species and affect bacterial plasma membranes and biosynthetic machinery to interfere with two-component systems, respiration, and macromolecular synthesis. These compounds represent a novel class of potential topical therapeutic agents.

  20. Antarctic analog for dilational bands on Europa

    NASA Astrophysics Data System (ADS)

    Hurford, T. A.; Brunt, K. M.

    2014-09-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  1. Antarctic Analog for Dilational Bands on Europa

    NASA Technical Reports Server (NTRS)

    Hurford, T. A.; Brunt, K. M.

    2014-01-01

    Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

  2. Visualizer cognitive style enhances visual creativity.

    PubMed

    Palmiero, Massimiliano; Nori, Raffaella; Piccardi, Laura

    2016-02-26

    In the last two decades, interest towards creativity has increased significantly since it was recognized as a skill and as a cognitive reserve and is now always more frequently used in ageing training. Here, the relationships between visual creativity and Visualization-Verbalization cognitive style were investigated. Fifty college students were administered the Creative Synthesis Task aimed at measuring the ability to construct creative objects and the Visualization-Verbalization Questionnaire (VVQ) aimed at measuring the attitude to preferentially use either imagery or verbal strategy while processing information. Analyses showed that only the originality score of inventions was positively predicted by the VVQ score: higher VVQ score (indicating the preference to use imagery) predicted originality of inventions. These results showed that the visualization strategy is involved especially in the originality dimension of creative objects production. In light of neuroimaging results, the possibility that different strategies, such those that involve motor processes, affect visual creativity is also discussed.

  3. Operational Lessons Learned from NASA Analog Missions

    NASA Technical Reports Server (NTRS)

    Arnold, Larissa S.

    2010-01-01

    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.

  4. Performance Effects of Display Incogruity in a Digital and Analog Clock Reading Task

    NASA Technical Reports Server (NTRS)

    Comstock, J. Raymond, Jr.; Derks, Peter L.

    2004-01-01

    In an era of increasing automation, it is important to design displays and input devices that minimize human error. In this context, information concerning the human response to the detection of incongruous information is important. Such incongruous information can be operationalized as unexpected (perhaps erroneous) information on which a decision by the human or operation by an automated system is based. In the aviation environment, decision making when faced with inadequate, incomplete, or incongruous information may occur in a failure scenario. An additional challenge facing the human operator in automated environments is maintaining alertness or vigilance. The vigilance issue is of particular concern as a factor that may interact with performance when faced with inadequate, incomplete, or incongruous information. From the literature on eye-scan behavior we know that the time spent looking at a particular display or indicator is a function of the type of information one is trying to discern from the display. For example, quick glances are all it takes for confirming that an indicator is in a normal position or range, whereas a continuous look of several seconds may be required for confirmation that a complex control input is having the desired effect. Important to consider is that while an extended look takes place, visual input from other sources may be missed. Much like an extended look, the interpretation of incongruous information may require extra time. The present experiment was designed to explore the performance consequences of a decision making task when incongruous information was presented. For this experiment a display incongruity was created on a subset of trials of a clock reading laboratory task. Display incongruity was made possible through presentation of 'impossible' times (e.g. 1:65 or 11:90). Subjects made 'same' 'different' decisions and keyboard responses to pairings of Analog-Analog (AA), Digital-Digital (DD), and Analog- Digital (AD

  5. Analogies between the Torque-Free Motion of a Rigid Body about a Fixed Point and Light Propagation in Anisotropic Media

    ERIC Educational Resources Information Center

    Bellver-Cebreros, Consuelo; Rodriguez-Danta, Marcelo

    2009-01-01

    An apparently unnoticed analogy between the torque-free motion of a rotating rigid body about a fixed point and the propagation of light in anisotropic media is stated. First, a new plane construction for visualizing this torque-free motion is proposed. This method uses an intrinsic representation alternative to angular momentum and independent of…

  6. Experiments on Evolving Software Models of Analog Circuits

    NASA Technical Reports Server (NTRS)

    Lohn, Jason D.

    1999-01-01

    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.

  7. Synthetic Biology: A Unifying View and Review Using Analog Circuits.

    PubMed

    Teo, Jonathan J Y; Woo, Sung Sik; Sarpeshkar, Rahul

    2015-08-01

    We review the field of synthetic biology from an analog circuits and analog computation perspective, focusing on circuits that have been built in living cells. This perspective is well suited to pictorially, symbolically, and quantitatively representing the nonlinear, dynamic, and stochastic (noisy) ordinary and partial differential equations that rigorously describe the molecular circuits of synthetic biology. This perspective enables us to construct a canonical analog circuit schematic that helps unify and review the operation of many fundamental circuits that have been built in synthetic biology at the DNA, RNA, protein, and small-molecule levels over nearly two decades. We review 17 circuits in the literature as particular examples of feedforward and feedback analog circuits that arise from special topological cases of the canonical analog circuit schematic. Digital circuit operation of these circuits represents a special case of saturated analog circuit behavior and is automatically incorporated as well. Many issues that have prevented synthetic biology from scaling are naturally represented in analog circuit schematics. Furthermore, the deep similarity between the Boltzmann thermodynamic equations that describe noisy electronic current flow in subthreshold transistors and noisy molecular flux in biochemical reactions has helped map analog circuit motifs in electronics to analog circuit motifs in cells and vice versa via a `cytomorphic' approach. Thus, a body of knowledge in analog electronic circuit design, analysis, simulation, and implementation may also be useful in the robust and efficient design of molecular circuits in synthetic biology, helping it to scale to more complex circuits in the future.

  8. Visual acuity test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003396.htm Visual acuity test To use the sharing features on this page, please enable JavaScript. The visual acuity test is used to determine the smallest ...

  9. Topological Methods for Visualization

    SciTech Connect

    Berres, Anne Sabine

    2016-04-07

    This slide presentation describes basic topological concepts, including topological spaces, homeomorphisms, homotopy, betti numbers. Scalar field topology explores finding topological features and scalar field visualization, and vector field topology explores finding topological features and vector field visualization.

  10. Visualizing Knowledge Domains.

    ERIC Educational Resources Information Center

    Borner, Katy; Chen, Chaomei; Boyack, Kevin W.

    2003-01-01

    Reviews visualization techniques for scientific disciplines and information retrieval and classification. Highlights include historical background of scientometrics, bibliometrics, and citation analysis; map generation; process flow of visualizing knowledge domains; measures and similarity calculations; vector space model; factor analysis;…

  11. Retrospective Analog Year Analyses Using NASA Satellite Data to Improve USDA's World Agricultural Supply and Demand Estimates

    NASA Technical Reports Server (NTRS)

    Teng, William; Shannon, Harlan

    2011-01-01

    The USDA World Agricultural Outlook Board (WAOB) is responsible for monitoring weather and climate impacts on domestic and foreign crop development. One of WAOB's primary goals is to determine the net cumulative effect of weather and climate anomalies on final crop yields. To this end, a broad array of information is consulted, including maps, charts, and time series of recent weather, climate, and crop observations; numerical output from weather and crop models; and reports from the press, USDA attach s, and foreign governments. The resulting agricultural weather assessments are published in the Weekly Weather and Crop Bulletin, to keep farmers, policy makers, and commercial agricultural interests informed of weather and climate impacts on agriculture. Because both the amount and timing of precipitation significantly affect crop yields, WAOB often uses precipitation time series to identify growing seasons with similar weather patterns and help estimate crop yields for the current growing season, based on observed yields in analog years. Historically, these analog years are visually identified; however, the qualitative nature of this method sometimes precludes the definitive identification of the best analog year. Thus, one goal of this study is to derive a more rigorous, statistical approach for identifying analog years, based on a modified coefficient of determination, termed the analog index (AI). A second goal is to compare the performance of AI for time series derived from surface-based observations vs. satellite-based measurements (NASA TRMM and other data).

  12. Realistic and Schematic Visuals.

    ERIC Educational Resources Information Center

    Heuvelman, Ard

    1996-01-01

    A study examined three different visual formats (studio presenter only, realistic visuals, or schematic visuals) of an educational television program. Recognition and recall of the abstract subject matter were measured in 101 adult viewers directly after the program and 3 months later. The schematic version yielded better recall of the program,…

  13. ESnet Visualization Widgets

    SciTech Connect

    Gopal Vaswani, Jon Dugan

    2012-07-01

    The ESnet Visualization widgets are various data visualization widgets for use in web browsers to aid in the visualization of computer networks. In particular the widgets are targetted at displaying timeseries and topology data. They were developed for use in the MyESnet portal but are general enough to be used other places. The widgets are built using the d3.js library.

  14. Semantic Visualization Mapping for Illustrative Volume Visualization

    NASA Astrophysics Data System (ADS)

    Rautek, P.; Bruckner, S.; Gröller, M. E.

    2009-04-01

    Measured and simulated data is usually divided into several meaningful intervals that are relevant to the domain expert. Examples from medicine are the specific semantics for different measuring modalities. A PET scan of a brain measures brain activity. It shows regions of homogeneous activity that are labeled by experts with semantic values such as low brain activity or high brain activity. Diffusion MRI data provides information about the healthiness of tissue regions and is classified by experts with semantic values like healthy, diseased, or necrotic. Medical CT data encode the measured density values in Hounsfield units. Specific intervals of the Hounsfield scale refer to different tissue types like air, soft tissue, bone, contrast enhanced vessels, etc. However, the semantic parameters from expert domains are not necessarily used to describe a mapping between the volume attributes and visual appearance. Volume rendering techniques commonly map attributes of the underlying data on visual appearance via a transfer function. Transfer functions are a powerful tool to achieve various visualization mappings. The specification of transfer functions is a complex task. The user has to have expert knowledge about the underlying rendering technique to achieve the desired results. Especially the specification of higher-dimensional transfer functions is challenging. Common user interfaces provide methods to brush in two dimensions. While brushing is an intuitive method to select regions of interest or to specify features, user interfaces for higher-dimensions are more challenging and often non-intuitive. For seismic data the situation is even more difficult since the data typically consists of many more volumetric attributes than for example medical datasets. Scientific illustrators are experts in conveying information by visual means. They also make use of semantics in a natural way describing visual abstractions such as shading, tone, rendering style, saturation

  15. Analog VLSI neural network integrated circuits

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  16. Analog and digital codes in the brain

    NASA Astrophysics Data System (ADS)

    Mochizuki, Yasuhiro; Shinomoto, Shigeru

    2014-02-01

    It has long been debated whether information in the brain is coded at the rate of neuronal spiking or at the precise timing of single spikes. Although this issue is essential to the understanding of neural signal processing, it is not easily resolved because the two mechanisms are not mutually exclusive. We suggest revising this coding issue so that one hypothesis is uniquely selected for a given spike train. To this end, we decide whether the spike train is likely to transmit a continuously varying analog signal or switching between active and inactive states. The coding hypothesis is selected by comparing the likelihood estimates yielded by empirical Bayes and hidden Markov models on individual data. The analysis method is applicable to generic event sequences, such as earthquakes, machine noises, and human communications, and enhances the gain in decoding signals and infers underlying activities.

  17. The Cannabinoid Acids, Analogs and Endogenous Counterparts

    PubMed Central

    Burstein, Sumner H.

    2015-01-01

    The cannabinoid acids are a structurally heterogeneous group of compounds some of which are endogenous molecules and others that are metabolites of phytocannabinoids. The prototypic endogenous substance is N-arachidonoyl glycine (NAgly) that is closely related in structure to the cannabinoid agonist anandamide. The most studied phytocannabinoid is Δ9–THC-11-oic acid, the principal metabolite of Δ9–THC. Both types of acids have in common several biological actions such as low affinity for CB1, anti-inflammatory activity and analgesic properties. This suggests that there may be similarities in their mechanism of action, a point that is discussed in this review. Also presented are reports on analogs of the acids that provide opportunities for the development of novel therapeutic agents, such as ajulemic acid. PMID:24731541

  18. Analog VLSI system for active drag reduction

    SciTech Connect

    Gupta, B.; Goodman, R.; Jiang, F.; Tai, Y.C.; Tung, S.; Ho, C.M.

    1996-10-01

    In today`s cost-conscious air transportation industry, fuel costs are a substantial economic concern. Drag reduction is an important way to reduce costs. Even a 5% reduction in drag translates into estimated savings of millions of dollars in fuel costs. Drawing inspiration from the structure of shark skin, the authors are building a system to reduce drag along a surface. Our analog VLSI system interfaces with microfabricated, constant-temperature shear stress sensors. It detects regions of high shear stress and outputs a control signal to activate a microactuator. We are in the process of verifying the actual drag reduction by controlling microactuators in wind tunnel experiments. We are encouraged that an approach similar to one that biology employs provides a very useful contribution to the problem of drag reduction. 9 refs., 21 figs.

  19. Cognitive performance in space and analogous environments.

    PubMed

    Casler, J G; Cook, J R

    1999-01-01

    Although human presence in space continues to expand, the literature contains relatively little coverage of human cognitive performance in the space operating environment. This article catalogs and compares the known investigations of human cognitive performance in space and in analogous environments. The methods, sample descriptions and treatments, and the results and limitations of the experiments or observations of 29 studies are compared with respect to 6 cognitive measures: (a) response time, (b) memory, (c) reasoning, (d) pattern recognition, (e) fine motor skills, and (f) dual-task performance. In general, the utility of the data is limited by small sample sizes, short observations periods, and homogeneity of the participant pool. Additionally, the variety of experimental methods used to date often makes generalization of results difficult. Although the combined results of these studies do not suggest a trend toward sustained cognitive performance impairment in the space operating environment, several cognitive performance measures do appear to be affected by an as yet undefined adaptation process.

  20. Holographic brain: a good analogy gone bad

    NASA Astrophysics Data System (ADS)

    Caulfield, H. John

    2002-07-01

    One way of honoring the world's two greatest holographers is to remove from their field the association with the offbeat world of the holographic mind. Basing itself on analogical musings of two very creative scientists who were themselves not holographers, this 'field' of the holographic brain has strayed far from science and into the absurd. So much absurdity has been written by so many people that the one legitimate study of holographic principle in dolphins has been grouped too often with the nonsense. Here is taken most of the 'target statements' form one book. We could not bear to read them all this closely. We will attempt to determine what tidbit of fact led to the statements and to suggest alternative explanations when there is something to explain.

  1. X-Rays from Green Pea Analogs

    NASA Astrophysics Data System (ADS)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.

  2. Scattering by interstellar graphite dust analog

    NASA Astrophysics Data System (ADS)

    Ahmed, Gazi A.; Gogoi, Ankur

    2014-10-01

    The analysis of optical scattering data of interstellar carbonaceous graphite dust analog at 543.5 nm, 594.5 nm and 632.8 nm laser wavelengths by using an original laboratory light scattering setup is presented. The setup primarily consisted of a laser source, optical units, aerosol sprayer, data acquisition system and associated instrumentation. The instrument measured scattered light signals from 10° to 170° in steps of 1°. The results of the measurements of the volume scattering function β(θ) and degree of linear polarization P(θ) of the carbonaceous graphite dust particles that were sprayed in front of the laser beam by using an aerosol sprayer were subsequently compared with theoretically generated Mie plots with estimated parameters.

  3. Synthesis and biodistribution of radioiodinated nicotine analogs

    SciTech Connect

    Chan, S.M.; Basmadjian, G.P.; Marten, D.F.; Sadek, S.; Magarian, R.A.; Grunder, J.R.; Ice, R.D.

    1984-01-01

    The authors reported previously on the synthesis and biodistribution of radioiodinated 5-iodonicotine. In their continuous effort to search for a potential brain as well as adrenal medulla imaging agent, the authors synthesized four radioiodinated nicotine analogs. The labeled compounds were prepared by brominating nicotinic acid, and reacting the acylated product with the appropriate amines to give the respective amides which were then reduced with diborane to the amines. I-125 labeling was done by halogen exchange. Biodistribution studies performed in female Sprague-Dawley rats showed that all these compounds were taken up rapidly by the brain and the adrenal. The highest uptake of all these compounds in both organs occurred at 2 minutes after tail vein injections. The organ:blood ratios at 2 minutes and the T/sub 1/3/ (min.) of radioactivity in these organs were compared.

  4. ANIMAL ANALOGIES IN FIRST IMPRESSIONS OF FACES.

    PubMed

    Zebrowitz, Leslie A; Wadlinger, Heather A; Luevano, Victor X; White, Benjamin M; Xing, Cai; Zhang, Yi

    2011-08-01

    Analogies between humans and animals based on facial resemblance have a long history. We report evidence for reverse anthropomorphism and the extension of facial stereotypes to lions, foxes, and dogs. In the stereotype extension, more positive traits were attributed to animals judged more attractive than con-specifics; more childlike traits were attributed to those judged more babyfaced. In the reverse anthropomorphism, human faces with more resemblance to lions, ascertained by connectionist modeling of facial metrics, were judged more dominant, cold, and shrewd, controlling attractiveness, babyfaceness, and sex. Faces with more resemblance to Labradors were judged warmer and less shrewd. Resemblance to foxes did not predict impressions. Results for lions and dogs were consistent with trait impressions of these animals and support the species overgeneralization hypothesis that evolutionarily adaptive reactions to particular animals are overgeneralized, with people perceived to have traits associated with animals their faces resemble. Other possible explanations are discussed.

  5. Atwood and Poggendorff: an insightful analogy

    NASA Astrophysics Data System (ADS)

    Coelho, R. L.; Borges, P. F.; Karam, R.

    2016-11-01

    Atwood’s treatise, in which the Atwood machine appears, was published in 1784. About 70 years later, Poggendorff showed experimentally that the weight of an Atwood machine is reduced when it is brought to motion. In the present paper, a twofold connection between this experiment and the Atwood machine is established. Firstly, if the Poggendorff apparatus is taken as an ideal one, the equations of motion of the apparatus coincide with the equations of motion of the compound Atwood machine. Secondly, if the Poggendorff apparatus, which works as a lever, is rebalanced, the equations of this equilibrium provide us with the solution for a compound Atwood machine with the same bodies. This analogy is pedagogically useful because it illustrates a common strategy to transform a dynamic in a static situation improving students’ comprehension of Newton’s laws and equilibrium.

  6. Cannabinoids, endocannabinoids, and related analogs in inflammation.

    PubMed

    Burstein, Sumner H; Zurier, Robert B

    2009-03-01

    This review covers reports published in the last 5 years on the anti-inflammatory activities of all classes of cannabinoids, including phytocannabinoids such as tetrahydrocannabinol and cannabidiol, synthetic analogs such as ajulemic acid and nabilone, the endogenous cannabinoids anandamide and related compounds, namely, the elmiric acids, and finally, noncannabinoid components of Cannabis that show anti-inflammatory action. It is intended to be an update on the topic of the involvement of cannabinoids in the process of inflammation. A possible mechanism for these actions is suggested involving increased production of eicosanoids that promote the resolution of inflammation. This differentiates these cannabinoids from cyclooxygenase-2 inhibitors that suppress the synthesis of eicosanoids that promote the induction of the inflammatory process.

  7. Analog circuit for controlling acoustic transducer arrays

    DOEpatents

    Drumheller, Douglas S.

    1991-01-01

    A simplified ananlog circuit is presented for controlling electromechanical transducer pairs in an acoustic telemetry system. The analog circuit of this invention comprises a single electrical resistor which replaces all of the digital components in a known digital circuit. In accordance with this invention, a first transducer in a transducer pair of array is driven in series with the resistor. The voltage drop across this resistor is then amplified and used to drive the second transducer. The voltage drop across the resistor is proportional and in phase with the current to the transducer. This current is approximately 90 degrees out of phase with the driving voltage to the transducer. This phase shift replaces the digital delay required by the digital control circuit of the prior art.

  8. Synthetic analogs of bacterial quorum sensors

    SciTech Connect

    Iyer, Rashi S.; Ganguly, Kumkum; Silks, Louis A.

    2013-01-08

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  9. Synthetic analogs of bacterial quorum sensors

    SciTech Connect

    Iyer, Rashi; Ganguly, Kumkum; Silks, Louis A

    2011-12-06

    Bacterial quorum-sensing molecule analogs having the following structures: ##STR00001## and methods of reducing bacterial pathogenicity, comprising providing a biological system comprising pathogenic bacteria which produce natural quorum-sensing molecule; providing a synthetic bacterial quorum-sensing molecule having the above structures and introducing the synthetic quorum-sensing molecule into the biological system comprising pathogenic bacteria. Further is provided a method of targeted delivery of an antibiotic, comprising providing a synthetic quorum-sensing molecule; chemically linking the synthetic quorum-sensing molecule to an antibiotic to produce a quorum-sensing molecule-antibiotic conjugate; and introducing the conjugate into a biological system comprising pathogenic bacteria susceptible to the antibiotic.

  10. Analogies and metaphors in clinical medicine.

    PubMed

    Masukume, Gwinyai; Zumla, Alimuddin

    2012-02-01

    Medicine is traditionally known as an 'art', and not an exact 'science'. Medical images of clinical signs and pathology were communicated through 'metaphors' in the 19th and early 20th centuries to make recognition easier in anticipation of the clinical counterpart when encountered in medical practice. They have served as teaching aids, enhancing memory retention for medical students, nurses and doctors and have withstood the test of time. Standard medical textbooks contain metaphors that have become entrenched in teaching, learning and examining in medical schools and hospitals worldwide. The continued use of metaphors has given rise to an ongoing debate, particularly in Africa, due to the usage of inappropriate or unfamiliar metaphors which are not locally or culturally relevant. Despite this, medical analogies will no doubt continue to be useful for medical education, clinical practice and 'aide memoirs' for examinations, and bring light humour, for a long time to come.

  11. Analogy between fluid cavitation and fracture mechanics

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  12. Four-gate transistor analog multiplier circuit

    NASA Technical Reports Server (NTRS)

    Mojarradi, Mohammad M. (Inventor); Blalock, Benjamin (Inventor); Cristoloveanu, Sorin (Inventor); Chen, Suheng (Inventor); Akarvardar, Kerem (Inventor)

    2011-01-01

    A differential output analog multiplier circuit utilizing four G.sup.4-FETs, each source connected to a current source. The four G.sup.4-FETs may be grouped into two pairs of two G.sup.4-FETs each, where one pair has its drains connected to a load, and the other par has its drains connected to another load. The differential output voltage is taken at the two loads. In one embodiment, for each G.sup.4-FET, the first and second junction gates are each connected together, where a first input voltage is applied to the front gates of each pair, and a second input voltage is applied to the first junction gates of each pair. Other embodiments are described and claimed.

  13. Disease Resistance Gene Analogs (RGAs) in Plants

    PubMed Central

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

    2015-01-01

    Plants have developed effective mechanisms to recognize and respond to infections caused by pathogens. Plant resistance gene analogs (RGAs), as resistance (R) gene candidates, have conserved domains and motifs that play specific roles in pathogens’ resistance. Well-known RGAs are nucleotide binding site leucine rich repeats, receptor like kinases, and receptor like proteins. Others include pentatricopeptide repeats and apoplastic peroxidases. RGAs can be detected using bioinformatics tools based on their conserved structural features. Thousands of RGAs have been identified from sequenced plant genomes. High-density genome-wide RGA genetic maps are useful for designing diagnostic markers and identifying quantitative trait loci (QTL) or markers associated with plant disease resistance. This review focuses on recent advances in structures and mechanisms of RGAs, and their identification from sequenced genomes using bioinformatics tools. Applications in enhancing fine mapping and cloning of plant disease resistance genes are also discussed. PMID:26287177

  14. [Analogies between the thymus and epidermis].

    PubMed

    De Panfilis, G

    1990-11-01

    In this paper, similarities between epidermis and thymus are reviewed. Both epidermis and thymus deal with an epithelial stroma harbouring dendritic cells, which are bone-marrow derived. Both epithelia are keratinized, and a map can be constructed illustrating histo-topographic and antigenic similarities between thymic epithelial cells distributed in various thymic zones (i.e. subcapsular cortex, outer cortex, inner cortex, medulla, outer layers of Hassall's bodies, inner layers of Hassall's bodies) and keratinocytes of different epidermal layers. By contrast, a possible similarity between thymocytes and Langerhans cells is not so easy to demonstrate, although both cell types are CD1 positive. Rather, in our opinion a comparison is preferable of thymocytes to Thy-1 positive dendritic epidermal cells, due to morphological, antigenic, functional and especially lineage similarities. Similarities between thymus and epidermis are clearly important dealing with analogous molecular interactions, namely, thymic epithelial cells/thymocytes versus keratinocytes/T-lymphocytes. Indeed, our recent investigations demonstrated that a subset of keratinocytes is ICAM-1 positive, and the whole keratinocyte population is LFA-3 positive. Since the interaction thymic epithelial cells (ICAM-1 and LFA-3 positive)/thymocytes (LFA-1 and CD2 positive) has been shown to be necessary for promotion of activation and maturation of thymocytes, the interaction keratinocytes (ICAM-1 and LFA-3 positive, as we demonstrated)/T-lymphocytes (LFA-1 and CD2 positive as well) might be, by analogy, important not only for the "homing" of T-lymphocytes within the epidermis, but also for the epidermis being considered a peripheral inductive site for T-cell activation and maturation.

  15. Automating analog design: Taming the shrew

    NASA Technical Reports Server (NTRS)

    Barlow, A.

    1990-01-01

    The pace of progress in the design of integrated circuits continues to amaze observers inside and outside of the industry. Three decades ago, a 50 transistor chip was a technological wonder. Fifteen year later, a 5000 transistor device would 'wow' the crowds. Today, 50,000 transistor chips will earn a 'not too bad' assessment, but it takes 500,000 to really leave an impression. In 1975 a typical ASIC device had 1000 transistors, took one year to first samples (and two years to production) and sold for about 5 cents per transistor. Today's 50,000 transistor gate array takes about 4 months from spec to silicon, works the first time, and sells for about 0.02 cents per transistor. Fifteen years ago, the single most laborious and error prone step in IC design was the physical layout. Today, most IC's never see the hand of a layout designer: and automatic place and route tool converts the engineer's computer captured schematic to a complete physical design using a gate array or a library of standard cells also created by software rather than by designers. CAD has also been a generous benefactor to the digital design process. The architect of today's digital systems creates the design using an RTL or other high level simulator. Then the designer pushes a button to invoke the logic synthesizer-optimizer tool. A fault analyzer checks the result for testability and suggests where scan based cells will improve test coverage. One obstinate holdout amidst this parade of progress is the automation of analog design and its reduction to semi-custom techniques. This paper investigates the application of CAD techniques to analog design.

  16. Optical analog-to-digital converter

    NASA Technical Reports Server (NTRS)

    Evanchuk, Vincent L. (Inventor)

    1984-01-01

    A method and apparatus for converting the intensity of an unknown optical signal (B) into an electrical signal in digital form utilizes two elongated optical attenuators (11, 13), one for the unknown optical signal from a source (10) and one for a known optical signal (A) from a variable source (12), a plurality of photodetectors (e.g., 17, 18) along each attenuator for detecting the intensity of the optical signals, and a plurality of comparators (e.g., 21) connected to the photodetectors in pairs to determine at what points being compared the attenuated known signal equals the attenuated unknown signal. The intensity of the unknown relative to the known is thus determined by the output of a particular comparator. That output is automatically encoded to a relative intensity value in digital form through a balancing feedback control (24) and encoder (23). The digital value may be converted to analog form in a D-to-A converter (27) and used to vary the source of the known signal so that the attenuated intensity of the known signal at a predetermined point (comparator 16) equals the attenuated intensity of the unknown signal at the predetermined point of comparison. If the known signal is then equal to the unknown, there is verification of the analog-to-digital conversion being complete. Otherwise the output of the comparator indicating equality at some other point along the attenuators will provide an output which is encoded and added, through an accumulator comprised of a register (25) and an adder (26), to a previous relative intensity value thereby to further vary the intensity of the known signal source. The steps are repeated until full conversion is verified.

  17. Auditory Attention to Frequency and Time: An Analogy to Visual Local-Global Stimuli

    ERIC Educational Resources Information Center

    Justus, Timothy; List, Alexandra

    2005-01-01

    Two priming experiments demonstrated exogenous attentional persistence to the fundamental auditory dimensions of frequency (Experiment 1) and time (Experiment 2). In a divided-attention task, participants responded to an independent dimension, the identification of three-tone sequence patterns, for both prime and probe stimuli. The stimuli were…

  18. A visually guided collision warning system with a neuromorphic architecture.

    PubMed

    Okuno, Hirotsugu; Yagi, Tetsuya

    2008-12-01

    We have designed a visually guided collision warning system with a neuromorphic architecture, employing an algorithm inspired by the visual nervous system of locusts. The system was implemented with mixed analog-digital integrated circuits consisting of an analog resistive network and field-programmable gate array (FPGA) circuits. The resistive network processes the interaction between the laterally spreading excitatory and inhibitory signals instantaneously, which is essential for real-time computation of collision avoidance with a low power consumption and a compact hardware. The system responded selectively to approaching objects of simulated movie images at close range. The system was, however, confronted with serious noise problems due to the vibratory ego-motion, when it was installed in a mobile miniature car. To overcome this problem, we developed the algorithm, which is also installable in FPGA circuits, in order for the system to respond robustly during the ego-motion.

  19. Visual examination apparatus

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fitzgerald, J. W.; Rositano, S. A. (Inventor)

    1973-01-01

    An automated visual examination apparatus for measuring visual sensitivity and mapping blind spot location is described. The apparatus includes a projection system for displaying to a patient a series of visual stimuli, a response switch enabling him to indicate his reaction to the stimuli, and a recording system responsive to both the visual stimuli per se and the patient's response. The recording system provides a correlated permanent record of both stimuli and response from which a substantive and readily apparent visual evaluation can be made.

  20. Synthesis and biological activity of nifuroxazide and analogs. II.

    PubMed

    Tavares, L C; Chisté, J J; Santos, M G; Penna, T C

    1999-09-01

    Nifuroxazyde and six analogs were synthesized by varying the substitute from the para-position of the benzenic ring and the heteroatom of the heterocyclic ring. The MIC of seven resultant compounds was determined by serial dilutions, testing the ATCC 25923 strain of Staphylococcus aureus. A significant increase in the anti-microbial activity of thyophenic analogs, as compared with furanic and pyrrholic analogs, was observed. In addition, unlike the cyano and hydroxyl groups, the acetyl group promoted anti-microbial activity.

  1. Assembly of a Neural Analog Computer. Phase 2

    DTIC Science & Technology

    1994-02-15

    Neural Computer . Analog VLSI Implementation of Neural Systems, IEEE Carver Mead, Mohammed Ismail, Eds., Kiluwer Academic Publishers, Boston, MA. 1989... Analog Neural Compuer With Modular Architecture for Real-Time Dynamic Computations . IEEE Transactions On Solid State Circuits V 27 82.-92 1992. 9...D FINAL REPORT PHASE II ONR CONTRACT # N00014-91-c-0204 ASSEMBLY OF A NEURAL ANALOG COMPUTER This documen: he- tbeen approved fox public reiease and

  2. Rapid Learning in a Children's Museum via Analogical Comparison.

    PubMed

    Gentner, Dedre; Levine, Susan C; Ping, Raedy; Isaia, Ashley; Dhillon, Sonica; Bradley, Claire; Honke, Garrett

    2016-01-01

    We tested whether analogical training could help children learn a key principle of elementary engineering-namely, the use of a diagonal brace to stabilize a structure. The context for this learning was a construction activity at the Chicago Children's Museum, in which children and their families build a model skyscraper together. The results indicate that even a single brief analogical comparison can confer insight. The results also reveal conditions that support analogical learning.

  3. A Quantitative Approach to Determine Analogous Areas Using Environmental Parameters

    DTIC Science & Technology

    2008-03-01

    determining the analogous areas. Instead of a MATLAB-based fuzzy logic approach, this method uses ArcMap software as a tool for performing analogous...area searches and display of results. This method is more efficient and user-friendly than the fuzzy logic approach, and allows users to easily...addition, a different approach is used in determining the analogous areas. Instead of a MATLAB-based, fuzzy logic approach, this method uses ArcMap

  4. Hardware Evolution of Analog Speed Controllers for a DC Motor

    NASA Technical Reports Server (NTRS)

    Gwaltney, David A.; Ferguson, Michael I.

    2003-01-01

    Evolvable hardware provides the capability to evolve analog circuits to produce amplifier and filter functions. Conventional analog controller designs employ these same functions. Analog controllers for the control of the shaft speed of a DC motor are evolved on an evolvable hardware platform utilizing a Field Programmable Transistor Array (FPTA). The performance of these evolved controllers is compared to that of a conventional proportional-integral (PI) controller.

  5. [Progressive visual agnosia].

    PubMed

    Sugimoto, Azusa; Futamura, Akinori; Kawamura, Mitsuru

    2011-10-01

    Progressive visual agnosia was discovered in the 20th century following the discovery of classical non-progressive visual agnosia. In contrast to the classical type, which is caused by cerebral vascular disease or traumatic injury, progressive visual agnosia is a symptom of neurological degeneration. The condition of progressive visual loss, including visual agnosia, and posterior cerebral atrophy was named posterior cortical atrophy (PCA) by Benson et al. (1988). Progressive visual agnosia is also observed in semantic dementia (SD) and other degenerative diseases, but there is a difference in the subtype of visual agnosia associated with these diseases. Lissauer (1890) classified visual agnosia into apperceptive and associative types, and it in most cases, PCA is associated with the apperceptive type. However, SD patients exhibit symptoms of associative visual agnosia before changing to those of semantic memory disorder. Insights into progressive visual agnosia have helped us understand the visual system and discover how we "perceive" the outer world neuronally, with regard to consciousness. Although PCA is a type of atypical dementia, its diagnosis is important to enable patients to live better lives with appropriate functional support.

  6. CRC handbook of neurohypophyseal hormone analogs. Volume 2

    SciTech Connect

    Jost, K.; Lebl, M.; Brtnik, F.

    1987-01-01

    This book is discussed in two parts. The Part 1 discusses the: Prohormones and Hormonogens of Neuro-hypophyseal Hormones, Analogs with Inhibitory properties. Analogs with Dissociated and/or High activities. Introduction. Uterotonic Activity. Galactogogic Activity. Pressor Activity. Antidiuretic Activity. References. Part 2 discusses the Other Important Activities. CNS Activities. Corticotropin- and ..beta..-Entriuretic Action. Natriferic Action. References. Practical Use in Human and Veterinary Medicine. Introduction. Methyloxytocin. Deamino-Oxytocin. Cargutocin. Glypressin. Octapressin. Desmopressin. Analogs Clinically Tried But Not Introduced into Production and Routine Clinical Practice. References. Tables of Analogs and Index.

  7. Non-analog Monte Carlo estimators for radiation momentum deposition

    SciTech Connect

    Densmore, Jeffery D; Hykes, Joshua M

    2008-01-01

    The standard method for calculating radiation momentum deposition in Monte Carlo simulations is the analog estimator, which tallies the change in a particle's momentum at each interaction with the matter. Unfortunately, the analog estimator can suffer from large amounts of statistical error. In this paper, we present three new non-analog techniques for estimating momentum deposition. Specifically, we use absorption, collision, and track-length estimators to evaluate a simple integral expression for momentum deposition that does not contain terms that can cause large amounts of statistical error in the analog scheme. We compare our new non-analog estimators to the analog estimator with a set of test problems that encompass a wide range of material properties and both isotropic and anisotropic scattering. In nearly all cases, the new non-analog estimators outperform the analog estimator. The track-length estimator consistently yields the highest performance gains, improving upon the analog-estimator figure of merit by factors of up to two orders of magnitude.

  8. Analog solar system model relates celestial bodies spatially

    NASA Technical Reports Server (NTRS)

    Baerg, H. R.

    1966-01-01

    Portable analog planetarium indicates the relative time and space angular locations of the sun and planets. Distance measuring scales, angular direction indicators, and typical probe trajectories are included.

  9. ISS Update: ISTAR -- International Space Station Testbed for Analog Research

    NASA Video Gallery

    NASA Public Affairs Officer Kelly Humphries interviews Sandra Fletcher, EVA Systems Flight Controller. They discuss the International Space Station Testbed for Analog Research (ISTAR) activity that...

  10. Physical analogy between continuum thermodynamics and classical mechanics.

    PubMed

    Umantsev, Alex

    2004-01-01

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

  11. Functional Visual Loss

    PubMed Central

    Bruce, Beau B; Newman, Nancy J

    2010-01-01

    Synopsis Neurologists frequently evaluate patients complaining of vision loss, especially when the patient has been examined by an ophthalmologist who has found no ocular disease. A significant proportion of patients presenting to the neurologist with visual complaints will have non-organic or functional visual loss. While there are examination techniques which can aid in the detection and diagnosis of functional visual loss, the frequency with which functional visual loss occurs concomitantly with organic disease warrants substantial caution on the part of the clinician. Furthermore, purely functional visual loss is never a diagnosis of exclusion, and must be supported by positive findings on examination that demonstrate normal visual function. The relationship of true psychological disease and functional visual loss is unclear and most patients respond well to simple reassurance. PMID:20638000

  12. RAVE: Rapid Visualization Environment

    NASA Technical Reports Server (NTRS)

    Klumpar, D. M.; Anderson, Kevin; Simoudis, Avangelos

    1994-01-01

    Visualization is used in the process of analyzing large, multidimensional data sets. However, the selection and creation of visualizations that are appropriate for the characteristics of a particular data set and the satisfaction of the analyst's goals is difficult. The process consists of three tasks that are performed iteratively: generate, test, and refine. The performance of these tasks requires the utilization of several types of domain knowledge that data analysts do not often have. Existing visualization systems and frameworks do not adequately support the performance of these tasks. In this paper we present the RApid Visualization Environment (RAVE), a knowledge-based system that interfaces with commercial visualization frameworks and assists a data analyst in quickly and easily generating, testing, and refining visualizations. RAVE was used for the visualization of in situ measurement data captured by spacecraft.

  13. Analyzing visual signals as visual scenes.

    PubMed

    Allen, William L; Higham, James P

    2013-07-01

    The study of visual signal design is gaining momentum as techniques for studying signals become more sophisticated and more freely available. In this paper we discuss methods for analyzing the color and form of visual signals, for integrating signal components into visual scenes, and for producing visual signal stimuli for use in psychophysical experiments. Our recommended methods aim to be rigorous, detailed, quantitative, objective, and where possible based on the perceptual representation of the intended signal receiver(s). As methods for analyzing signal color and luminance have been outlined in previous publications we focus on analyzing form information by discussing how statistical shape analysis (SSA) methods can be used to analyze signal shape, and spatial filtering to analyze repetitive patterns. We also suggest the use of vector-based approaches for integrating multiple signal components. In our opinion elliptical Fourier analysis (EFA) is the most promising technique for shape quantification but we await the results of empirical comparison of techniques and the development of new shape analysis methods based on the cognitive and perceptual representations of receivers. Our manuscript should serve as an introductory guide to those interested in measuring visual signals, and while our examples focus on primate signals, the methods are applicable to quantifying visual signals in most taxa.

  14. Visual dependence and BPPV.

    PubMed

    Agarwal, K; Bronstein, A M; Faldon, M E; Mandalà, M; Murray, K; Silove, Y

    2012-06-01

    The increased visual dependence noted in some vestibular patients may be secondary to their vertigo. We examine whether a single, brief vertigo attack, such as in benign paroxysmal positional vertigo (BPPV), modifies visual dependency. Visual dependency was measured before and after the Hallpike manoeuvre with (a) the Rod and Frame and the Rod and Disc techniques whilst seated and (b) the postural sway induced by visual roll-motion stimulation. Three subject groups were studied: 20 patients with BPPV (history and positive Hallpike manoeuvre; PosH group), 20 control patients (history of BPPV but negative Hallpike manoeuvre; NegH group) and 20 normal controls. Our findings show that while both patient groups showed enhanced visual dependency, the PosH and the normal control group decreased visual dependency on repetition of the visual tasks after the Hallpike manoeuvre. NegH patients differed from PosH patients in that their high visual dependency did not diminish on repetition of the visual stimuli; they scored higher on the situational characteristic questionnaire ('visual vertigo' symptoms) and showed higher incidence of migraine. We conclude that long term vestibular symptoms increase visual dependence but a single BPPV attack does not increase it further. Repetitive visual motion stimulation induces adaptation in visual dependence in peripheral vestibular disorders such as BPPV. A positional form of vestibular migraine may underlie the symptoms of some patients with a history of BPPV but negative Hallpike manoeuvre. The finding that they have non adaptable increased visual dependency may explain visuo-vestibular symptoms in this group and, perhaps more widely, in patients with migraine.

  15. Event-Based Computation of Motion Flow on a Neuromorphic Analog Neural Platform

    PubMed Central

    Giulioni, Massimiliano; Lagorce, Xavier; Galluppi, Francesco; Benosman, Ryad B.

    2016-01-01

    Estimating the speed and direction of moving objects is a crucial component of agents behaving in a dynamic world. Biological organisms perform this task by means of the neural connections originating from their retinal ganglion cells. In artificial systems the optic flow is usually extracted by comparing activity of two or more frames captured with a vision sensor. Designing artificial motion flow detectors which are as fast, robust, and efficient as the ones found in biological systems is however a challenging task. Inspired by the architecture proposed by Barlow and Levick in 1965 to explain the spiking activity of the direction-selective ganglion cells in the rabbit's retina, we introduce an architecture for robust optical flow extraction with an analog neuromorphic multi-chip system. The task is performed by a feed-forward network of analog integrate-and-fire neurons whose inputs are provided by contrast-sensitive photoreceptors. Computation is supported by the precise time of spike emission, and the extraction of the optical flow is based on time lag in the activation of nearby retinal neurons. Mimicking ganglion cells our neuromorphic detectors encode the amplitude and the direction of the apparent visual motion in their output spiking pattern. Hereby we describe the architectural aspects, discuss its latency, scalability, and robustness properties and demonstrate that a network of mismatched delicate analog elements can reliably extract the optical flow from a simple visual scene. This work shows how precise time of spike emission used as a computational basis, biological inspiration, and neuromorphic systems can be used together for solving specific tasks. PMID:26909015

  16. Touch Accelerates Visual Awareness

    PubMed Central

    Lo Verde, Luca; Alais, David

    2017-01-01

    To efficiently interact with the external environment, our nervous system combines information arising from different sensory modalities. Recent evidence suggests that cross-modal interactions can be automatic and even unconscious, reflecting the ecological relevance of cross-modal processing. Here, we use continuous flash suppression (CFS) to directly investigate whether haptic signals can interact with visual signals outside of visual awareness. We measured suppression durations of visual gratings rendered invisible by CFS either during visual stimulation alone or during visuo-haptic stimulation. We found that active exploration of a haptic grating congruent in orientation with the suppressed visual grating reduced suppression durations both compared with visual-only stimulation and to incongruent visuo-haptic stimulation. We also found that the facilitatory effect of touch on visual suppression disappeared when the visual and haptic gratings were mismatched in either spatial frequency or orientation. Together, these results demonstrate that congruent touch can accelerate the rise to consciousness of a suppressed visual stimulus and that this unconscious cross-modal interaction depends on visuo-haptic congruency. Furthermore, since CFS suppression is thought to occur early in visual cortical processing, our data reinforce the evidence suggesting that visuo-haptic interactions can occur at the earliest stages of cortical processing. PMID:28210486

  17. ANALOG: a program for estimating paleoclimate parameters using the method of modern analogs

    USGS Publications Warehouse

    Schweitzer, Peter N.

    1994-01-01

    Beginning in the 1970s with CLIMAP, paleoclimatologists have been trying to derive quantitative estimates of climatic parameters from the sedimentary record. In general the procedure is to observe the modern distribution of some component of surface sediment that depends on climate, find an empirical relationship between climate and the character of sediments, then extrapolate past climate by studying older sediments in the same way. Initially the empirical relationship between climate and components of the sediment was determined using a multiple regression technique (Imbrie and Kipp, 1971). In these studies sea-floor sediments were examined to determine the percentage of various species of planktonic foraminifera present in them. Supposing that the distribution of foraminiferal assemblages depended strongly on the extremes of annual sea-surface temperature (SST), the foraminiferal assemblages (refined through use of varimax factor analysis) were regressed against the average SST during the coolest and warmest months of the year. The result was a set of transfer functions, equations that could be used to estimate cool and warm SST from the faunal composition of a sediment sample. Assuming that the ecological preference of the species had remained constant throughout the last several hundred thousand years, these transfer functions could be used to estimate SSTs during much of the late Pleistocene. Hutson (1980) and Overpeck, Webb, and Prentice (1985) proposed an alternative approach to estimating paleoclimatic parameters. Their 'method of modern analogs' revolved not around the existence of a few climatically-sensitive faunal assemblages but rather on the expectation that similar climatic regimes should foster similar faunal and floral assemblages. From a large pool of modern samples, those few are selected whose faunal compositions are most similar to a given fossil sample. Paleoclimate estimates are derived using the climatic character of only the most similar

  18. Pareidolias: complex visual illusions in dementia with Lewy bodies.

    PubMed

    Uchiyama, Makoto; Nishio, Yoshiyuki; Yokoi, Kayoko; Hirayama, Kazumi; Imamura, Toru; Shimomura, Tatsuo; Mori, Etsuro

    2012-08-01

    Patients rarely experience visual hallucinations while being observed by clinicians. Therefore, instruments to detect visual hallucinations directly from patients are needed. Pareidolias, which are complex visual illusions involving ambiguous forms that are perceived as meaningful objects, are analogous to visual hallucinations and have the potential to be a surrogate indicator of visual hallucinations. In this study, we explored the clinical utility of a newly developed instrument for evoking pareidolic illusions, the Pareidolia test, in patients with dementia with Lewy bodies-one of the most common causes of visual hallucinations in the elderly. Thirty-four patients with dementia with Lewy bodies, 34 patients with Alzheimer's disease and 26 healthy controls were given the Pareidolia test. Patients with dementia with Lewy bodies produced a much greater number of pareidolic illusions compared with those with Alzheimer's disease or controls. A receiver operating characteristic analysis demonstrated that the number of pareidolias differentiated dementia with Lewy bodies from Alzheimer's disease with a sensitivity of 100% and a specificity of 88%. Full-length figures and faces of people and animals accounted for >80% of the contents of pareidolias. Pareidolias were observed in patients with dementia with Lewy bodies who had visual hallucinations as well as those who did not have visual hallucinations, suggesting that pareidolias do not reflect visual hallucinations themselves but may reflect susceptibility to visual hallucinations. A sub-analysis of patients with dementia with Lewy bodies who were or were not treated with donepzil demonstrated that the numbers of pareidolias were correlated with visuoperceptual abilities in the former and with indices of hallucinations and delusional misidentifications in the latter. Arousal and attentional deficits mediated by abnormal cholinergic mechanisms and visuoperceptual dysfunctions are likely to contribute to the development

  19. Attention and visual memory in visualization and computer graphics.

    PubMed

    Healey, Christopher G; Enns, James T

    2012-07-01

    A fundamental goal of visualization is to produce images of data that support visual analysis, exploration, and discovery of novel insights. An important consideration during visualization design is the role of human visual perception. How we "see" details in an image can directly impact a viewer's efficiency and effectiveness. This paper surveys research on attention and visual perception, with a specific focus on results that have direct relevance to visualization and visual analytics. We discuss theories of low-level visual perception, then show how these findings form a foundation for more recent work on visual memory and visual attention. We conclude with a brief overview of how knowledge of visual attention and visual memory is being applied in visualization and graphics. We also discuss how challenges in visualization are motivating research in psychophysics.

  20. Visual field asymmetries in visual evoked responses

    PubMed Central

    Hagler, Donald J.

    2014-01-01

    Behavioral responses to visual stimuli exhibit visual field asymmetries, but cortical folding and the close proximity of visual cortical areas make electrophysiological comparisons between different stimulus locations problematic. Retinotopy-constrained source estimation (RCSE) uses distributed dipole models simultaneously constrained by multiple stimulus locations to provide separation between individual visual areas that is not possible with conventional source estimation methods. Magnetoencephalography and RCSE were used to estimate time courses of activity in V1, V2, V3, and V3A. Responses to left and right hemifield stimuli were not significantly different. Peak latencies for peripheral stimuli were significantly shorter than those for perifoveal stimuli in V1, V2, and V3A, likely related to the greater proportion of magnocellular input to V1 in the periphery. Consistent with previous results, sensor magnitudes for lower field stimuli were about twice as large as for upper field, which is only partially explained by the proximity to sensors for lower field cortical sources in V1, V2, and V3. V3A exhibited both latency and amplitude differences for upper and lower field responses. There were no differences for V3, consistent with previous suggestions that dorsal and ventral V3 are two halves of a single visual area, rather than distinct areas V3 and VP. PMID:25527151

  1. Using Analogies to Overcome Misconceptions: A Technology Course Example.

    ERIC Educational Resources Information Center

    Gokhale, Anu A.

    1996-01-01

    Both a control group and experimental group (23 students each) received a lecture on direct current circuits; the experimental group also participated in a lab using a device explaining an analogy for electric current. The experimental group's posttest scores were much higher, indicating that the analogical device helped overcome student…

  2. Synthesis and Antimalarial Activities of Cyclen 4-Aminoquinoline Analogs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an attempt to augment the efficacy of 7-chloro 4-aminoquinoline analogs and also to overcome resistance to anti-malarial agents we synthesized three cyclen analogs of chloroquine (4,6,7). Compound 4 displays the most potent in vitro and in vivo antimalarial activities. It displays an IC50 of 7.5 ...

  3. Stereoselective synthesis of nicotinamide beta-riboside and nucleoside analogs.

    PubMed

    Franchetti, Palmarisa; Pasqualini, Michela; Petrelli, Riccardo; Ricciutelli, Massimo; Vita, Patrizia; Cappellacci, Loredana

    2004-09-20

    The beta-anomers of N-ribofuranosylnicotine-3-carboxamide (beta-NAR) and its nicotinic acid analog (beta-NaR) were obtained by stereoselective synthesis via glycosylation of the presilylated bases under Vorbruggen's protocol. A NAR analog, methylated in position 3 of the ribosylic moiety, is also reported.

  4. Antiviral nucleoside analogs phosphorylation by nucleoside diphosphate kinase.

    PubMed

    Gallois-Montbrun, S; Veron, M; Deville-Bonne, D

    2004-05-01

    The reaction of NDP kinase was studied in vitro with several antiviral derivatives, using kinetic steady state and presteady state analysis. The enzyme is highly efficient with natural nucleotides but most of the analogs are slow substrates. The catalytic efficiency, also related to the affinity of the analog, is mainly dependent on the presence of a 3'-OH group on the ribose moiety.

  5. Modeling heart rate variability in healthy humans: a turbulence analogy.

    PubMed

    Lin, D C; Hughson, R L

    2001-02-19

    Many complex systems share similar statistical characteristics. In this Letter, a turbulence analogy is proposed for the long-term heart rate variability of healthy humans. Based on such an analogy, the equivalence of an inertial range is found and a cascade model, which captures the statistical properties of the heart rate data, is given.

  6. Q-Analogies: A Test of Quantitative Reasoning.

    ERIC Educational Resources Information Center

    Chase, Clinton I.; Johnson, Judith J.

    The initial steps necessary for constructing an analogies test are described. Basic mathematics being the context, the aim of the test is to predict student performance in research statistics courses characteristic of graduate education and social science programs. Items involving analogies in a quantitative context were built, sorted into two…

  7. The interplay of conflict and analogy in multidisciplinary teams.

    PubMed

    Paletz, Susannah B F; Schunn, Christian D; Kim, Kevin H

    2013-01-01

    Creative teamwork in multidisciplinary teams is a topic of interest to cognitive psychologists on the one hand, and to both social and organizational psychologists on the other. However, the interconnections between cognitive and social layers have been rarely explored. Drawing on mental models and dissonance theories, the current study takes a central variable studied by cognitive psychologists-analogy-and examines its relationship to a central variable examined by social psychologists-conflict. In an observational, field study, over 11h of audio-video data from conversations of the Mars Exploration Rover scientists were coded for different types of analogy and micro-conflicts that reveal the character of underlying psychological mechanisms. Two different types of time-lagged logistic models applied to these data revealed asymmetric patterns of associations between analogy and conflict. Within-domain analogies, but not within-discipline or outside-discipline analogies, preceded science and work process conflicts, suggesting that in multidisciplinary teams, representational gaps in very close domains will be more likely to spark conflict. But analogies also occurred in reaction to conflict: Process and negative conflicts, but not task conflicts, preceded within-discipline analogies, but not to within-domain or outside-discipline analogies. This study demonstrates ways in which cognition can be bidirectionally tied to social processes and discourse.

  8. Exploring the Impacts of Analogies on Computer Hardware

    ERIC Educational Resources Information Center

    Dincer, Serkan

    2011-01-01

    In the last few decades, analogy, which is considered as a special case for reasoning, has attracted a great deal of attention from cognitive scientists. Although analogy was rarely applied in previous decades, now it is often considered by educators and researchers as a strategy to provide creative solutions and poetic writing (Paris & Glynn,…

  9. The Effectiveness of Teaching Science with Pictorial Analogies.

    ERIC Educational Resources Information Center

    Lin, Huann-shyang; And Others

    1996-01-01

    This study uses a conceptual problem-solving test to investigate the effect of a series of pictorial analogies on the concepts of density, pressure, and atmospheric pressure in Year Eight classrooms. Findings indicate that students taught with the pictorial analogies scored significantly higher than their counterparts. Low achievers were the most…

  10. The Role of Writing in Learning from Analogies

    ERIC Educational Resources Information Center

    Klein, Perry D.; Piacente-Cimini, Sabrina; Williams, Laura A.

    2007-01-01

    This study examines the role of writing in learning scientific principles through analogy. Seventy-two university students observed two demonstrations concerning one of three topics: buoyant force of a fluid, projectile motion or forces internal to a system. Each composed an analogy on one of the topics through speaking-only, writing-only, or…

  11. Analogical Reasoning in the Classroom: Insights from Cognitive Science

    ERIC Educational Resources Information Center

    Vendetti, Michael S.; Matlen, Bryan J.; Richland, Lindsey E.; Bunge, Silvia A.

    2015-01-01

    Applying knowledge from one context to another is a notoriously difficult problem, both for children and adults, but lies at the heart of educational endeavors. Analogical reasoning is a cognitive underpinning of the ability to notice and draw similarities across contexts. Reasoning by analogy is especially challenging for students, who must…

  12. Young Children's Analogical Problem Solving: Gaining Insights from Video Displays

    ERIC Educational Resources Information Center

    Chen, Zhe; Siegler, Robert S.

    2013-01-01

    This study examined how toddlers gain insights from source video displays and use the insights to solve analogous problems. Two- to 2.5-year-olds viewed a source video illustrating a problem-solving strategy and then attempted to solve analogous problems. Older but not younger toddlers extracted the problem-solving strategy depicted in the video…

  13. The Impact of Analogy on L3 Reading Comprehension

    ERIC Educational Resources Information Center

    Karami, Hossein; Nodoushan, Mohammad Ali Salmani

    2014-01-01

    Little research has been conducted to investigate the effect of analogy on third language (L3, hereafter) reading comprehension though some experts believe that it has facilitating and debilitating effects on L1 and L2 respectively. This article explores the effect of analogies on reading comprehension of expository texts by students of English as…

  14. Using Analogy to Overcome Misconceptions about Conservation of Matter.

    ERIC Educational Resources Information Center

    Stavy, Ruth

    1991-01-01

    This study (n=192) examined the use of analogical instruction to overcome misconceptions about conservation of matter. Students who understood the concept conservation of matter when iodine was evaporated were able to transfer their understanding to the evaporation of acetone. This indicates that teaching by analogy can be an effective tool in…

  15. Where Concepts Meet Percepts: Stimulating Analogical Thought in Children.

    ERIC Educational Resources Information Center

    Flick, Larry

    1991-01-01

    Reports an instructional application of a theory of analogical reasoning. Uses the grinding of a sugar cube as an explanatory-predictive analogy for state transitions of water as a stimulus for promoting associations with other appropriate experiences in elementary school students. (PR)

  16. Analogical Reasoning in Children with Specific Language Impairment

    ERIC Educational Resources Information Center

    Leroy, Sandrine; Parisse, Christophe; Maillart, Christelle

    2012-01-01

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

  17. Use of Analogy in Learning Physics: The Role of Representations

    ERIC Educational Resources Information Center

    Podolefsky, Noah S.; Finkelstein, Naoh D.

    2006-01-01

    Previous studies have demonstrated that analogies can promote student learning in physics and can be productively taught to students to support their learning, under certain conditions. We build on these studies to explore the use of analogy by students in a large introductory college physics course. In the first large-scale study of its kind, we…

  18. Analysis of Attention and Analogical Reasoning in Children of Poverty

    ERIC Educational Resources Information Center

    Weatherholt, Tara N.; Harris, Ruby C.; Burns, Barbara M.; Clement, Catherine

    2006-01-01

    This study examined the relationship between specific attentional aspects of processing capacity and analogical reasoning in children from low-income families. 77 children aged 48-77 (M = 56.7) months were assessed on an analogical reasoning task (matrices subtest of the Kaufman Brief Intelligence Test) and on computerized attention tasks designed…

  19. Using Analogies to Prevent Misconceptions about Chemical Equilibrium

    ERIC Educational Resources Information Center

    Sahin Pekmez, Esin

    2010-01-01

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

  20. Self-Generated Analogical Models of Respiratory Pathways

    ERIC Educational Resources Information Center

    Lee, Yeung Chung

    2015-01-01

    Self-generated analogical models have emerged recently as alternatives to teacher-supplied analogies and seem to have good potential to promote deep learning and scientific thinking. However, studies of the ways and contexts in which students generate these models are still too limited to allow a fuller appraisal of these models' effectiveness in…

  1. Using Self-Generated Analogies in Teaching of Thermodynamics

    ERIC Educational Resources Information Center

    Haglund, Jesper; Jeppsson, Fredrik

    2012-01-01

    Using self-generated analogies has been proposed as a method in a constructivist tradition for students to learn about a new subject, by use of what they previously know. We report on a group exercise on using self-generated analogies to make sense of two thermodynamic processes, reversible adiabatic expansion and free adiabatic expansion of an…

  2. Cognitive Determinants of Analogical Reasoning on Intelligence Tests.

    ERIC Educational Resources Information Center

    Holzman, Thomas G.; And Others

    The cognitive determinants of number analogy performance were studied by systematically manipulating the processing demands imposed by the items. To explore sources of developmental differences in analogical reasoning, subjects were included from two age levels, grades 4 and 5 and college. To allow the investigation of individual differences in…

  3. Small, low power analog-to-digital converter

    NASA Technical Reports Server (NTRS)

    Dunn, R. D.; Fullerton, D. H.

    1968-01-01

    A small, low-power, high-speed, 8-bit analog-to-digital converter using silicon chip integrated circuits is suitable for use in airborne test data systems. The successive approximation method of analog-to-digital conversion is used to generate the digital output.

  4. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, Mark M.; Shoup, Timothy

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  5. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, Mark M.; Shoup, Timothy

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is ›.sup.18 F!-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an .alpha.-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of .alpha.-aminoisobutyric acid.

  6. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, M.M.; Shoup, T.

    1998-09-15

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  7. Amino acid analogs for tumor imaging

    DOEpatents

    Goodman, M.M.; Shoup, T.

    1998-10-06

    The invention provides novel amino acid compounds of use in detecting and evaluating brain and body tumors. These compounds combine the advantageous properties of 1-amino-cycloalkyl-1-carboxylic acids, namely, their rapid uptake and prolonged retention in tumors with the properties of halogen substituents, including certain useful halogen isotopes including fluorine-18, iodine-123, iodine-125, iodine-131, bromine-75, bromine-76, bromine-77 and bromine-82. In one aspect, the invention features amino acid compounds that have a high specificity for target sites when administered to a subject in vivo. Preferred amino acid compounds show a target to non-target ratio of at least 5:1, are stable in vivo and substantially localized to target within 1 hour after administration. An especially preferred amino acid compound is [{sup 18}F]-1-amino-3-fluorocyclobutane-1-carboxylic acid (FACBC). In another aspect, the invention features pharmaceutical compositions comprised of an {alpha}-amino acid moiety attached to either a four, five, or a six member carbon-chain ring. In addition, the invention features analogs of {alpha}-aminoisobutyric acid.

  8. Vitamin E Analogs as Radiation Response Modifiers

    PubMed Central

    Singh, Pankaj K.; Krishnan, Sunil

    2015-01-01

    The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine. PMID:26366184

  9. Applying analog integrated circuits for HERO protection

    NASA Technical Reports Server (NTRS)

    Willis, Kenneth E.; Blachowski, Thomas J.

    1994-01-01

    One of the most efficient methods for protecting electro-explosive devices (EED's) from HERO and ESD is to shield the EED in a conducting shell (Faraday cage). Electrical energy is transferred to the bridge by means of a magnetic coupling which passes through a portion of the conducting shell that is made from a magnetically permeable but electrically conducting material. This technique was perfected by ML Aviation, a U.K. company, in the early 80's, and was called a Radio Frequency Attenuation Connector (RFAC). It is now in wide use in the U.K. Previously, the disadvantage of RFAC over more conventional methods was its relatively high cost, largely driven by a thick film hybrid circuit used to switch the primary of the transformer. Recently, through a licensing agreement, this technology has been transferred to the U.S. and significant cost reductions and performance improvements have been achieved by the introduction of analog integrated circuits. An integrated circuit performs the following functions: (1) Chops the DC input to a signal suitable for driving the primary of the transformer; (2) Verifies the input voltage is above a threshold; (3) Verifies the input voltage is valid for a pre set time before enabling the device; (4) Provides thermal protection of the circuit; and (5) Provides an external input for independent logic level enabling of the power transfer mechanism. This paper describes the new RFAC product and its applications.

  10. Theoretical ingredients of a Casimir analog computer

    PubMed Central

    Rodriguez, Alejandro W.; McCauley, Alexander P.; Joannopoulos, John D.; Johnson, Steven G.

    2010-01-01

    We derive a correspondence between the contour integration of the Casimir stress tensor in the complex-frequency plane and the electromagnetic response of a physical dissipative medium in a finite real-frequency bandwidth. The consequences of this correspondence are at least threefold: First, the correspondence makes it easier to understand Casimir systems from the perspective of conventional classical electromagnetism, based on real-frequency responses, in contrast to the standard imaginary-frequency point of view based on Wick rotations. Second, it forms the starting point of finite-difference time-domain numerical techniques for calculation of Casimir forces in arbitrary geometries. Finally, this correspondence is also key to a technique for computing quantum Casimir forces at micrometer scales using antenna measurements at tabletop (e.g., centimeter) scales, forming a type of analog computer for the Casimir force. Superficially, relationships between the Casimir force and the classical electromagnetic Green’s function are well known, so one might expect that any experimental measurement of the Green’s function would suffice to calculate the Casimir force. However, we show that the standard forms of this relationship lead to infeasible experiments involving infinite bandwidth or exponentially growing fields, and a fundamentally different formulation is therefore required. PMID:20460309

  11. Phonon analog of topological nodal semimetals

    NASA Astrophysics Data System (ADS)

    Po, Hoi Chun; Bahri, Yasaman; Vishwanath, Ashvin

    2016-05-01

    Topological band structures in electronic systems like topological insulators and semimetals give rise to highly unusual physical properties. Analogous topological effects have also been discussed in bosonic systems, but the novel phenomena typically occur only when the system is excited by finite-frequency probes. A mapping recently proposed by C. L. Kane and T. C. Lubensky [Nat. Phys. 10, 39 (2014), 10.1038/nphys2835], however, establishes a closer correspondence. It relates the zero-frequency excitations of mechanical systems to topological zero modes of fermions that appear at the edges of an otherwise gapped system. Here we generalize the mapping to systems with an intrinsically gapless bulk. In particular, we construct mechanical counterparts of topological semimetals. The resulting gapless bulk modes are physically distinct from the usual acoustic Goldstone phonons and appear even in the absence of continuous translation invariance. Moreover, the zero-frequency phonon modes feature adjustable momenta and are topologically protected as long as the lattice coordination is unchanged. Such protected soft modes with tunable wave vector may be useful in designing mechanical structures with fault-tolerant properties.

  12. The MARS2013 Mars analog mission.

    PubMed

    Groemer, Gernot; Soucek, Alexander; Frischauf, Norbert; Stumptner, Willibald; Ragonig, Christoph; Sams, Sebastian; Bartenstein, Thomas; Häuplik-Meusburger, Sandra; Petrova, Polina; Evetts, Simon; Sivenesan, Chan; Bothe, Claudia; Boyd, Andrea; Dinkelaker, Aline; Dissertori, Markus; Fasching, David; Fischer, Monika; Föger, Daniel; Foresta, Luca; Fritsch, Lukas; Fuchs, Harald; Gautsch, Christoph; Gerard, Stephan; Goetzloff, Linda; Gołebiowska, Izabella; Gorur, Paavan; Groemer, Gerhard; Groll, Petra; Haider, Christian; Haider, Olivia; Hauth, Eva; Hauth, Stefan; Hettrich, Sebastian; Jais, Wolfgang; Jones, Natalie; Taj-Eddine, Kamal; Karl, Alexander; Kauerhoff, Tilo; Khan, Muhammad Shadab; Kjeldsen, Andreas; Klauck, Jan; Losiak, Anna; Luger, Markus; Luger, Thomas; Luger, Ulrich; McArthur, Jane; Moser, Linda; Neuner, Julia; Orgel, Csilla; Ori, Gian Gabriele; Paternesi, Roberta; Peschier, Jarno; Pfeil, Isabella; Prock, Silvia; Radinger, Josef; Ramirez, Barbara; Ramo, Wissam; Rampey, Mike; Sams, Arnold; Sams, Elisabeth; Sandu, Oana; Sans, Alejandra; Sansone, Petra; Scheer, Daniela; Schildhammer, Daniel; Scornet, Quentin; Sejkora, Nina; Stadler, Andrea; Stummer, Florian; Taraba, Michael; Tlustos, Reinhard; Toferer, Ernst; Turetschek, Thomas; Winter, Egon; Zanella-Kux, Katja

    2014-05-01

    We report on the MARS2013 mission, a 4-week Mars analog field test in the northern Sahara. Nineteen experiments were conducted by a field crew in Morocco under simulated martian surface exploration conditions, supervised by a Mission Support Center in Innsbruck, Austria. A Remote Science Support team analyzed field data in near real time, providing planning input for the management of a complex system of field assets; two advanced space suit simulators, four robotic vehicles, an emergency shelter, and a stationary sensor platform in a realistic work flow were coordinated by a Flight Control Team. A dedicated flight planning group, external control centers for rover tele-operations, and a biomedical monitoring team supported the field operations. A 10 min satellite communication delay and other limitations pertinent to human planetary surface activities were introduced. The fields of research for the experiments were geology, human factors, astrobiology, robotics, tele-science, exploration, and operations research. This paper provides an overview of the geological context and environmental conditions of the test site and the mission architecture, in particular the communication infrastructure emulating the signal travel time between Earth and Mars. We report on the operational work flows and the experiments conducted, including a deployable shelter prototype for multiple-day extravehicular activities and contingency situations.

  13. [Petrological Analysis of Astrophysical Dust Analog Evolution

    NASA Technical Reports Server (NTRS)

    Rietmeijer, Frans J. M.

    1997-01-01

    This project "Petrological analysis of astrophysical dust analog evolution" was initiated to try to understand the vapor phase condensation, and the nature of the reaction products, in circumstellar environments, such as the solar nebula 4,500 Myrs ago, and in the interstellar medium. Telescope-based infrared [IR] spectroscopy offers a broad-scale inventory of the various types of dust in these environments but no details on small-scale variations in terms of chemistry and morphology and petrological phase relationships. Vapor phase condensation in these environments is almost certainly a non-equilibrium process. The main challenge to this research was to document the nature of this process that, based on astrophysical observations, seems to yield compositionally consistent materials. This observation may suggest a predictable character during non-equilibrium condensation. These astrophysical environments include two chemically distinct, that is, oxygen-rich and carbon-rich environments. The former is characterized by silicates the latter by carbon-bearing solids. According to cosmological models of stellar evolution circumstellar dust accreted into protoplanets wherein thermal and/or aqueous processes will alter the dust under initially, non-equilibrium conditions.

  14. Photometric properties of Mars soils analogs

    USGS Publications Warehouse

    Pommerol, A.; Thomas, N.; Jost, B.; Beck, P.; Okubo, C.; McEwen, A.S.

    2013-01-01

    We have measured the bidirectional reflectance of analogs of dry, wet, and frozen Martian soils over a wide range of phase angles in the visible spectral range. All samples were produced from two geologic samples: the standard JSC Mars-1 soil simulant and Hawaiian basaltic sand. In a first step, experiments were conducted with the dry samples to investigate the effects of surface texture. Comparisons with results independently obtained by different teams with similar samples showed a satisfying reproducibility of the photometric measurements as well as a noticeable influence of surface textures resulting from different sample preparation procedures. In a second step, water was introduced to produce wet and frozen samples and their photometry investigated. Optical microscope images of the samples provided information about their microtexture. Liquid water, even in relatively low amount, resulted in the disappearance of the backscattering peak and the appearance of a forward-scattering peak whose intensity increases with the amount of water. Specular reflections only appeared when water was present in an amount large enough to allow water to form a film at the surface of the sample. Icy samples showed a wide variability of photometric properties depending on the physical properties of the water ice. We discuss the implications of these measurements in terms of the expected photometric behavior of the Martian surface, from equatorial to circum-polar regions. In particular, we propose some simple photometric criteria to improve the identification of wet and/or icy soils from multiple observations under different geometries.

  15. Serial Pixel Analog-to-Digital Converter

    SciTech Connect

    Larson, E D

    2010-02-01

    This method reduces the data path from the counter to the pixel register of the analog-to-digital converter (ADC) from as many as 10 bits to a single bit. The reduction in data path width is accomplished by using a coded serial data stream similar to a pseudo random number (PRN) generator. The resulting encoded pixel data is then decoded into a standard hexadecimal format before storage. The high-speed serial pixel ADC concept is based on the single-slope integrating pixel ADC architecture. Previous work has described a massively parallel pixel readout of a similar architecture. The serial ADC connection is similar to the state-of-the art method with the exception that the pixel ADC register is a shift register and the data path is a single bit. A state-of-the-art individual-pixel ADC uses a single-slope charge integration converter architecture with integral registers and “one-hot” counters. This implies that parallel data bits are routed among the counter and the individual on-chip pixel ADC registers. The data path bit-width to the pixel is therefore equivalent to the pixel ADC bit resolution.

  16. Weathering of Mars - Antarctic analog studies

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.; Drake, M. J.

    1981-01-01

    Subaerial extrusion of lavas above permafrost is proposed as a possible weathering regime leading to the presence of Martian surface fines, and the characteristics of this process are examined through a study of the analogous altered terrestrial basalts from Antarctica. On the basis of mineralogical and petrological analyses of samples obtained from core cuttings recovered by the Dry Valley Drilling Program from rocks predominantly of an aklalic basalt-phonolite suite, it is found that in the absence of liquid water, weathering is geologically slow, and that zeolites predominate over clays as secondary mineral. Of the possible weathering processes proposed for Mars, it is concluded that both subaerial extrusion and subpermafrost intrusion of lavas involving liquid water would be less important volumetrically than the hydrothermal alteration of impact melt sheets if water were present during an intense phase of early bombardment, or than subsequent solid-gas alteration reactions. It is thus predicted that the present Martian fines should contain a major contribution from the ancient crust as typified by the southern cratered highlands, and a lesser contribution from the younger basaltic lavas.

  17. Natural Analog Studies at Pena Blanca, Mexico

    SciTech Connect

    A.M. Simmons

    2005-07-11

    The significance of the Pena Blanca uranium deposits in the State of Chihuahua, Mexico as potential natural analogs for a nuclear waste repository in unsaturated welded tuff was first recognized in the 1980s. In the 1970s, the Pena Blanca region was a major target of uranium exploration and exploitation by the Mexican government. Since then the Nopal I uranium deposit has been studied extensively by researchers in the U.S., Mexico, and Europe. The Nopal I deposit represents an environment similar to that of the proposed high-level radioactive waste repository at Yucca Mountain in many ways. Both are located in semi-arid regions. Both are located in Tertiary rhyolitic tuffs overlying carbonate rocks that have been subjected to basin and range-style tectonic deformation. Both are located in a chemically oxidizing, unsaturated zone 200 m or more above the water table. The alteration of uraninite to secondary minerals at Nopal I may be similar to the alteration of uranium fuel rods in this type of setting. Investigations at Nopal I and in the surrounding Sierra Pena Blanca have included detailed outcrop mapping, hydrologic and isotopic studies of flow and transport, studies of mineral alteration, modeling, and performance assessment.

  18. Thermal Conductivity Measurements on consolidated Soil Analogs

    NASA Astrophysics Data System (ADS)

    Seiferlin, K.; Heimberg, M.; Thomas, N.

    2007-08-01

    Heat transport in porous media such as soils and regolith is significantly reduced compared to the properties of compact samples of the same material. The bottle neck for solid state heat transport is the contact area between adjacent grains. For "dry" and unconsolidated materials the contact areas and thus the thermal conductivity are extremely small. Sintering and cementation are two processes that can increase the cross section of interstitial bonds signifcantly. On Mars, cementation can be caused by condensation of water or carbon dioxide ice from the vapor phase, or from salts and minerals that fall out from aqueous solutions. We produced several artificially cemented samples, using small glass beads of uniform size as soil analog. The cementation is achieved by initially molten wax that is mixed with the glass beads while liqiud. The wax freezes preferably at the contact points between grains, thus minimizing surface energy, and consolidates the samples. The thermal conductivity of these samples is then measured in vacuum. We present the results of these measurements and compare them with theoretical models. The observed range of thermal conductivity values can explain some, but not all of the variations in thermal intertia that can be seen in TES remote sensing data.

  19. Interstellar and Planetary Analogs in the Laboratory

    NASA Technical Reports Server (NTRS)

    Salama, Farid

    2013-01-01

    We present and discuss the unique capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to investigate the interaction of ionizing radiation (UV, charged particles) with molecular species (neutral molecules, radicals and ions) and carbonaceous grains in the Solar System and in the Interstellar Medium (ISM). COSmIC stands for Cosmic Simulation Chamber, a laboratory chamber where interstellar and planetary analogs are generated, processed and analyzed. It is composed of a pulsed discharge nozzle (PDN) expansion that generates a free jet supersonic expansion in a plasma cavity coupled to two ultrahigh-sensitivity, complementary in situ diagnostics: a cavity ring down spectroscopy (CRDS) system for photonic detection and a Reflectron time-of-flight mass spectrometer (ReTOF-MS) for mass detection. This setup allows the study of molecules, ions and solids under the low temperature and high vacuum conditions that are required to simulate some interstellar, circumstellar and planetary physical environments providing new fundamental insights on the molecular level into the processes that are critical to the chemistry in the ISM, circumstellar and planet forming regions, and on icy objects in the Solar System. Recent laboratory results that were obtained using COSmIC will be discussed, in particular the progress that have been achieved in monitoring in the laboratory the formation of solid particles from their gas-phase molecular precursors in environments as varied as circumstellar outflow and planetary atmospheres.

  20. The halogen analogs of thiolated gold nanoclusters

    SciTech Connect

    Jiang, Deen; Walter, Michael

    2012-01-01

    Is it possible to replace all the thiolates in a thiolated gold nanocluster with halogens while still maintaining the geometry and the electronic structure? In this work, we show from density functional theory that such halogen analogs of thiolated gold nanoclusters are highly likely. Using Au{sub 25}X{sub 18}{sup -} as an example, where X = F, Cl, Br, or I replaces -SR, we find that Au{sub 25}Cl{sub 18}{sup -} demonstrates a high similarity to Au{sub 25}(SR){sub 18}{sup -} by showing Au-Cl distances, Cl-Au-Cl angles, band gap, and frontier orbitals similar to those in Au{sub 25}(SR){sub 18}{sup -}. DFT-based global minimization also indicates the energetic preference of staple formation for the Au{sub 25}Cl{sub 18}{sup -} cluster. The similarity between Au{sub m}(SR){sub n} and Au{sub m}X{sub n} could be exploited to make viable Au{sub m}X{sub n} clusters and to predict structures for Au{sub m}(SR){sub n}.