Science.gov

Sample records for huxley correspondence letters

  1. Secondary Students' Internalization of Letter-Sound Correspondences.

    ERIC Educational Resources Information Center

    Ryder, Randall J.; Graves, Michael F.

    1980-01-01

    A study of seventh-, ninth-, and eleventh-grade students' ability to apply letter-sound correspondence to synthetic words indicates that, although by seventh grade, students have largely mastered letter-sound correspondences, low ability students do not approach the same mastery as average and high ability students until the eleventh grade. (JMF)

  2. 19 CFR 145.3 - Opening of letter class mail; reading of correspondence prohibited.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Opening of letter class mail; reading of... Opening of letter class mail; reading of correspondence prohibited. (a) Matter in addition to... addressee has given written authorization for the opening. (c) Reading of correspondence. No Customs...

  3. 19 CFR 145.3 - Opening of letter class mail; reading of correspondence prohibited.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sender or the addressee has given written authorization for the reading. (d) Other types of... 19 Customs Duties 2 2010-04-01 2010-04-01 false Opening of letter class mail; reading of... Opening of letter class mail; reading of correspondence prohibited. (a) Matter in addition...

  4. 19 CFR 145.3 - Opening of letter class mail; reading of correspondence prohibited.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... sender or the addressee has given written authorization for the reading. (d) Other types of... 19 Customs Duties 2 2013-04-01 2013-04-01 false Opening of letter class mail; reading of... Opening of letter class mail; reading of correspondence prohibited. (a) Matter in addition...

  5. 19 CFR 145.3 - Opening of letter class mail; reading of correspondence prohibited.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... sender or the addressee has given written authorization for the reading. (d) Other types of... 19 Customs Duties 2 2011-04-01 2011-04-01 false Opening of letter class mail; reading of... Opening of letter class mail; reading of correspondence prohibited. (a) Matter in addition...

  6. 19 CFR 145.3 - Opening of letter class mail; reading of correspondence prohibited.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... sender or the addressee has given written authorization for the reading. (d) Other types of... 19 Customs Duties 2 2012-04-01 2012-04-01 false Opening of letter class mail; reading of... Opening of letter class mail; reading of correspondence prohibited. (a) Matter in addition...

  7. Use of Simple and Conditional Letter-Sound Correspondences in Children's Pronunciations of Synthetic Words.

    ERIC Educational Resources Information Center

    Chapman, Robin S.; And Others

    Conditional letter sound correspondences (LSC) in which the pronunciation of a letter is determined by its graphemic environment were studied. Conditional LSC patterns selected for investigation were the c, g, and vowel-in-final-e patterns. The study had two aims: (1) to gather normative data for LSC generalizations and (2) to examine, for each…

  8. Pronunciation of Synthetic Words with Predictable and Unpredictable Letter-Sound Correspondences. Technical Report No. 71.

    ERIC Educational Resources Information Center

    Calfee, Robert C.; And Others

    The acquisition of Literacy Project's basic goal is to determine the processes by which children learn to read, and to identify reasons many fail to learn. One part of the process is the formation of correspondences between letter patterns and the sounds for which they stand. To determine the extent of such correspondences, tests of pronunciation…

  9. Instruction in Letter-Sound Correspondences for Children with Autism and Limited Speech

    ERIC Educational Resources Information Center

    Benedek-Wood, Elizabeth; McNaughton, David; Light, Janice

    2016-01-01

    This study used a multiple probe across participants' research design to evaluate the effects of instruction on the acquisition of letter-sound correspondences (LSCs) by three young children with autism spectrum disorder and limited speech. All three children (ages 3-5 years) reached criterion for identifying the LSCs targeted during instruction,…

  10. Brain sensitivity to print emerges when children learn letter-speech sound correspondences.

    PubMed

    Brem, Silvia; Bach, Silvia; Kucian, Karin; Guttorm, Tomi K; Martin, Ernst; Lyytinen, Heikki; Brandeis, Daniel; Richardson, Ulla

    2010-04-27

    The acquisition of reading skills is a major landmark process in a human's cognitive development. On the neural level, a new functional network develops during this time, as children typically learn to associate the well-known sounds of their spoken language with unfamiliar characters in alphabetic languages and finally access the meaning of written words, allowing for later reading. A critical component of the mature reading network located in the left occipito-temporal cortex, termed the "visual word-form system" (VWFS), exhibits print-sensitive activation in readers. When and how the sensitivity of the VWFS to print comes about remains an open question. In this study, we demonstrate the initiation of occipito-temporal cortex sensitivity to print using functional MRI (fMRI) (n = 16) and event-related potentials (ERP) (n = 32) in a controlled, longitudinal training study. Print sensitivity of fast (<250 ms) processes in posterior occipito-temporal brain regions accompanied basic associative learning of letter-speech sound correspondences in young (mean age 6.4 +/- 0.08 y) nonreading kindergarten children, as shown by concordant ERP and fMRI results. The occipito-temporal print sensitivity thus is established during the earliest phase of reading acquisition in childhood, suggesting that a crucial part of the later reading network first adopts a role in mapping print and sound.

  11. Friendly Letters on the Correspondence of Helen Keller, Anne Sullivan, and Alexander Graham Bell.

    ERIC Educational Resources Information Center

    Blatt, Burton

    1985-01-01

    Excerpts from the letters between Alexander Graham Bell and Anne Sullivan and Helen Keller are given to illustrate the educational and personal growth of Helen Keller as well as the educational philosophy of Bell regarding the education of the deaf blind. (DB)

  12. Letters

    NASA Astrophysics Data System (ADS)

    2001-03-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE Contents: Force on a pendulum Sound slows down Bond is back Force on a pendulum The simple pendulum has been used by several educationalists for investigating the patterns of thinking among students and their observations that Aristotelian thinking persists among students at college level. I had also considered the simple pendulum in my 1985 letter in Physics Today [1], so I was interested to read the test given by Lenka Czudková and Jana Musilová [2]. When students were asked to draw net forces acting on the particle at various positions, 31.9% of students believed that the net force was tangential to the particle's path the whole time. To me this is no surprise because in our derivation of the equation for the period of a simple pendulum we assume that the unbalanced sine component provides the restoring force for the harmonic motion of the bob. Of course, Czudková and Musilová's question asked students for the net force on the particle, not the component. The student's answer fits well with the logic of the equilibrium of forces and the parallelogram law. Lastly, let me bring out the similarity between the student's answer and the thinking of George Gamow. He used to call positrons 'donkey' electrons because of their displacement against the applied force, before Paul Dirac termed them positrons. Victor Weisskeptf told me this anecdote in a letter in May 1982. References [1] Sathe D 1985 Phys. Today 38 144 [2] Czudková L and Musilová J 2000 Phys. Educ. 35 428 Dileep V Sathe Dadawala Jr College, Pune, India Sound slows down Without wanting to stir up more trouble amongst the already muddy waters of Physics teaching, consider how many times you have heard (or, more worryingly, read) this: 'Sound waves travel faster in a denser material' But...The velocity of simple longitudinal waves in a bulk medium is given by v = (K/ρ)1/2 where K is

  13. Letters

    NASA Astrophysics Data System (ADS)

    2001-03-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE Contents: Force on a pendulum Sound slows down Bond is back Force on a pendulum The simple pendulum has been used by several educationalists for investigating the patterns of thinking among students and their observations that Aristotelian thinking persists among students at college level. I had also considered the simple pendulum in my 1985 letter in Physics Today [1], so I was interested to read the test given by Lenka Czudková and Jana Musilová [2]. When students were asked to draw net forces acting on the particle at various positions, 31.9% of students believed that the net force was tangential to the particle's path the whole time. To me this is no surprise because in our derivation of the equation for the period of a simple pendulum we assume that the unbalanced sine component provides the restoring force for the harmonic motion of the bob. Of course, Czudková and Musilová's question asked students for the net force on the particle, not the component. The student's answer fits well with the logic of the equilibrium of forces and the parallelogram law. Lastly, let me bring out the similarity between the student's answer and the thinking of George Gamow. He used to call positrons 'donkey' electrons because of their displacement against the applied force, before Paul Dirac termed them positrons. Victor Weisskeptf told me this anecdote in a letter in May 1982. References [1] Sathe D 1985 Phys. Today 38 144 [2] Czudková L and Musilová J 2000 Phys. Educ. 35 428 Dileep V Sathe Dadawala Jr College, Pune, India Sound slows down Without wanting to stir up more trouble amongst the already muddy waters of Physics teaching, consider how many times you have heard (or, more worryingly, read) this: 'Sound waves travel faster in a denser material' But...The velocity of simple longitudinal waves in a bulk medium is given by v = (K/ρ)1/2 where K is

  14. The correspondence of Thomas Dale (1700-1750): Botany in the transatlantic Republic of Letters.

    PubMed

    Cook, William J

    2012-03-01

    This paper seeks to provide a full account of the life and career of Dr. Thomas Dale (1700-1750), with particular reference to his botanical works and correspondence. Born in Hoxton, London, Dale studied medicine at Leiden and engaged fully in the social, literary and epistolary network in which botany was practised in eighteenth-century England. In 1730, however, Dale relocated to the British colonial port of Charles Town, South Carolina. Here he continued to engage in a transatlantic network of botanical exchange and discussion, corresponding on equal and reciprocal terms with his former colleagues in England. Where Dale differs from naturalists in South Carolina before him is that his motives for pursuing botany and for corresponding with English naturalists were located firmly in the New World. Such a conclusion forms a valuable, albeit small contribution to models for the development of national scientific cultures in the imperial world. Similarly, Dale's pursuit of botanical information in South Carolina provides a small amount of material with which to illustrate currently fashionable models for the mediated exchange and circulation of scientific knowledge.

  15. Evolution and Education: Lessons from Thomas Huxley

    ERIC Educational Resources Information Center

    Lyons, Sherrie Lynne

    2010-01-01

    Thomas Huxley more than anyone else was responsible for disseminating Darwin's theory in the western world and maintained that investigating the history of life should be regarded as a purely scientific question free of theological speculation. The content and rhetorical strategy of Huxley's defense of evolution is analyzed. Huxley argued that the…

  16. Letters

    NASA Astrophysics Data System (ADS)

    2001-07-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: Alternative view of education in Zambia Pedantry or compromise Alternative view of education in Zambia I have just read the 'On the Map' report of the International School of Lusaka with very mixed feelings (Physics Education, March 2001). I have recently spent some time in Zambia, in Lusaka, and share Sue Pears' love for the country and the Zambians. The ISL is indeed a good, prestigious school, similar to International Schools in many other countries. But, as in most other developing countries, there is enormous variation between the different types of schooling, and the ISL is at one end of the spectrum. Most schools in Zambia are less favoured. Zambia is a wonderful, beautiful country full of the most friendly and resourceful people I know. It is also a very poor country. It is a country of enormous contrasts and its schools reflect that variation. It has a tiny, affluent 'middle' class of professionals, politicians, businessmen, employees of international businesses and NGOs—nearly all paid from overseas budgets. It has an enormous majority of poor folk, cheerfully living in very basic conditions but sharing their lives in extended families without complaint. The government is virtually bankrupt, and consequently those paid by the government—teachers, police, nurses etc—get a pittance. The wage for a teacher in a typical school is #20 per month (compared to a typical teacher in the UK who gets 100 times more, about #2000 per month). The GNP in Zambia is about 1 per day per person, and this has to pay for all the schools, hospitals, police, and the civic infrastructure that we take so much for granted (the GNP in UK is about 60 per day per person). Consequently most state schools do not have resources; they have a classroom and a teacher but little else. What resources the school has will be paid for by the school fees that every

  17. Letters

    NASA Astrophysics Data System (ADS)

    2001-07-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: Alternative view of education in Zambia Pedantry or compromise Alternative view of education in Zambia I have just read the 'On the Map' report of the International School of Lusaka with very mixed feelings (Physics Education, March 2001). I have recently spent some time in Zambia, in Lusaka, and share Sue Pears' love for the country and the Zambians. The ISL is indeed a good, prestigious school, similar to International Schools in many other countries. But, as in most other developing countries, there is enormous variation between the different types of schooling, and the ISL is at one end of the spectrum. Most schools in Zambia are less favoured. Zambia is a wonderful, beautiful country full of the most friendly and resourceful people I know. It is also a very poor country. It is a country of enormous contrasts and its schools reflect that variation. It has a tiny, affluent 'middle' class of professionals, politicians, businessmen, employees of international businesses and NGOs—nearly all paid from overseas budgets. It has an enormous majority of poor folk, cheerfully living in very basic conditions but sharing their lives in extended families without complaint. The government is virtually bankrupt, and consequently those paid by the government—teachers, police, nurses etc—get a pittance. The wage for a teacher in a typical school is #20 per month (compared to a typical teacher in the UK who gets 100 times more, about #2000 per month). The GNP in Zambia is about 1 per day per person, and this has to pay for all the schools, hospitals, police, and the civic infrastructure that we take so much for granted (the GNP in UK is about 60 per day per person). Consequently most state schools do not have resources; they have a classroom and a teacher but little else. What resources the school has will be paid for by the school fees that every

  18. Letters

    NASA Astrophysics Data System (ADS)

    2001-01-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: Maths for physics? Help! Fire! Energy and mass Maths for physics? As a maths graduate working as a university research associate I should be well qualified to support my daughter, who has just started AS-level physics, with the maths she needs for the course. There seems to be little integration between the maths and physics departments, so that maths needed for physics has not yet been covered in maths lessons. This is a problem I remember from my own school days, but the shorter timescale and modular nature of the AS and A2 levels means that it is essential that this mismatch of knowledge is resolved now. I would like to know whether physics teachers in the UK have encountered this problem and whether there is a deficiency in the maths syllabus in relation to the requirements of the AS and A2 levels in Physics or whether this is a problem peculiar to my daughter's school. Eleanor Parent of A-level student, Sheffield, UK Help! Fire! Is there a crisis in physics education? Is physics didactics coming to an end? Yes and no. Being a delegate from Norway at the on-going conference Physics on Stage (6-10 November 2000) at CERN in Geneva, I have had the opportunity to discuss this with people from all over Europe. Yes, there is a crisis. (Look at the proceedings for details on this.) I'd like to take a broader look at this situation. Like Hari Seldon in Isaac Asimov's Foundation Trilogy, I believe that there is nothing like a real crisis to get things going... Famous is the quote from the American Patent Office around 1890: 'Everything has been invented that could be invented'. Fortunately, this spurred action. The Michelson and Morley experiment heralded a most exciting period for physics. Just a cosmic blink later we put a person on the Moon. Coming back to the crisis - I am certain that in the near future we will see an interesting development

  19. Letters

    NASA Astrophysics Data System (ADS)

    2001-09-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: M-set as metaphor The abuse of algebra M-set as metaphor 'To see a World in a Grain of Sand And a Heaven in a Wild Flower Hold Infinity in the palm of your hand And Eternity in an hour' William Blake's implied relativity of spatial and temporal scales is intriguing and, given the durability of this worlds-within-worlds concept (he wrote in 1803) in art, literature and science, the blurring of distinctions between the very large and the very small must strike some kind of harmonious chord in the human mind. Could this concept apply to the physical world? To be honest, we cannot be absolutely sure. Most cosmological thinking still retains the usual notions of a finite universe and an absolute size scale extending from smallest to largest objects. In the boundless realm of mathematics, however, the story is quite different. The M-set was discovered by the French mathematician Benoit Mandelbrot in 1980, created by just a few simple lines of computer code that are repeated recursively. As in Blake's poem, this 'world' has no bottom we have an almost palpable archetype for the concept of infinity. I would use the word 'tangible', but one of the defining features of the M-set is that nowhere in the labyrinth can one find a surface smooth enough for a tangent. Upon magnification even surfaces that appeared to be smooth explode with quills and scrolls and lightning bolts and spiral staircases. And there is something more, something truly sublime. Observe a small patch with unlimited magnifying power and, as you observe the M-set on ever-smaller scales, down through literally endless layers of ornate structure, you occasionally come upon a rapidly expanding cortex of dazzling colour with a small black structure at its centre. The black spot appears to be the M-set itself! There is no end to the hierarchy, no bottom-most level, just endless recursive

  20. Letters

    NASA Astrophysics Data System (ADS)

    2001-09-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: M-set as metaphor The abuse of algebra M-set as metaphor 'To see a World in a Grain of Sand And a Heaven in a Wild Flower Hold Infinity in the palm of your hand And Eternity in an hour' William Blake's implied relativity of spatial and temporal scales is intriguing and, given the durability of this worlds-within-worlds concept (he wrote in 1803) in art, literature and science, the blurring of distinctions between the very large and the very small must strike some kind of harmonious chord in the human mind. Could this concept apply to the physical world? To be honest, we cannot be absolutely sure. Most cosmological thinking still retains the usual notions of a finite universe and an absolute size scale extending from smallest to largest objects. In the boundless realm of mathematics, however, the story is quite different. The M-set was discovered by the French mathematician Benoit Mandelbrot in 1980, created by just a few simple lines of computer code that are repeated recursively. As in Blake's poem, this 'world' has no bottom we have an almost palpable archetype for the concept of infinity. I would use the word 'tangible', but one of the defining features of the M-set is that nowhere in the labyrinth can one find a surface smooth enough for a tangent. Upon magnification even surfaces that appeared to be smooth explode with quills and scrolls and lightning bolts and spiral staircases. And there is something more, something truly sublime. Observe a small patch with unlimited magnifying power and, as you observe the M-set on ever-smaller scales, down through literally endless layers of ornate structure, you occasionally come upon a rapidly expanding cortex of dazzling colour with a small black structure at its centre. The black spot appears to be the M-set itself! There is no end to the hierarchy, no bottom-most level, just endless recursive

  1. Letters

    NASA Astrophysics Data System (ADS)

    2001-05-01

    The Editor welcomes letters, by e-mail to ped@iop.org or by post to Dirac House, Temple Back, Bristol BS1 6BE, UK. Contents: Quantum uncertainties Reflections in a plastic box A brief history of quantum physics Correction Grammar and gender Quantum uncertainties Whilst I enjoyed Gesche Pospiech's article ('Uncertainty and complementarity: the heart of quantum physics' 2000 Phys. Educ. 35 393 9) I would like to expand on two comments he makes. Firstly the author claims that QM is linear, and a consequence of this is that any two superimposed states form an admissible third state. This is rather too sweeping, as it is true only for degenerate states. Otherwise quantum mechanics would allow a continuum of energies between states by a simple admixture of levels. The proof of this statement is trivial. For a Hamiltonian H and two orthogonal wavefunctions, ψ1 and ψ2 with energies E1 and E2 then (ψ1 + ψ2) is not an eigenfunction of that Hamiltonian as H(ψ1 + ψ2) = E1ψ1 + E2ψ2 ≠ E(ψ1 + ψ2) for any value of E, unless E1 = E2. Secondly Pospiech states that quantum objects show wave- or particle-like behaviour, depending on the measuring apparatus, and that occasionally experiments (such as Taylor's) reveal both. I would contest the validity of this type of thinking. All experiments on quantum objects reveal both types of behaviour—even ones which simply show straight line motion of photons. What is important, in addition, is our interpretation of the results. It takes an understanding of QED, for example, to see that an experiment which otherwise shows particle behaviour is, in fact, showing quantum behaviour. More contentiously though I would suggest that detection apparatus is incapable of detecting anything other than particles. Wave-like behaviour is revealed only by an analysis of the paths the particle could have taken. In other words, the interference of continuous fields sometimes predicts the same results when the detection is averaged over many events

  2. Supplemental Flashcard Drill Methods for Efficiently Helping At-Risk Kindergartners Make Letter-Sound Correspondences: Does Presentation Arrangement of Words Matter?

    ERIC Educational Resources Information Center

    Griffin, Crystal; Joseph, Laurice M.

    2015-01-01

    Variations of supplemental flashcard drill and practice instructional procedures (i.e., massed practice and interspersal presentation arrangements of words) were examined for six kindergartners who struggled making letter-sound correspondences. Findings revealed that the children demonstrated the highest learning rates when the presentation…

  3. Circles of Confidence in Correspondence: Modeling Confidentiality and Secrecy in Knowledge Exchange Networks of Letters and Drawings in the Early Modern Period.

    PubMed

    van den Heuvel, Charles; Weingart, Scott B; Spelt, Nils; Nellen, Henk

    2016-01-01

    Science in the early modern world depended on openness in scholarly communication. On the other hand, a web of commercial, political, and religious conflicts required broad measures of secrecy and confidentiality; similar measures were integral to scholarly rivalries and plagiarism. This paper analyzes confidentiality and secrecy in intellectual and technological knowledge exchange via letters and drawings. We argue that existing approaches to understanding knowledge exchange in early modern Europe--which focus on the Republic of Letters as a unified entity of corresponding scholars--can be improved upon by analyzing multilayered networks of communication. We describe a data model to analyze circles of confidence and cultures of secrecy in intellectual and technological knowledge exchanges. Finally, we discuss the outcomes of a first experiment focusing on the question of how personal and professional/official relationships interact with confidentiality and secrecy, based on a case study of the correspondence of Hugo Grotius. PMID:27071301

  4. Circles of Confidence in Correspondence: Modeling Confidentiality and Secrecy in Knowledge Exchange Networks of Letters and Drawings in the Early Modern Period.

    PubMed

    van den Heuvel, Charles; Weingart, Scott B; Spelt, Nils; Nellen, Henk

    2016-01-01

    Science in the early modern world depended on openness in scholarly communication. On the other hand, a web of commercial, political, and religious conflicts required broad measures of secrecy and confidentiality; similar measures were integral to scholarly rivalries and plagiarism. This paper analyzes confidentiality and secrecy in intellectual and technological knowledge exchange via letters and drawings. We argue that existing approaches to understanding knowledge exchange in early modern Europe--which focus on the Republic of Letters as a unified entity of corresponding scholars--can be improved upon by analyzing multilayered networks of communication. We describe a data model to analyze circles of confidence and cultures of secrecy in intellectual and technological knowledge exchanges. Finally, we discuss the outcomes of a first experiment focusing on the question of how personal and professional/official relationships interact with confidentiality and secrecy, based on a case study of the correspondence of Hugo Grotius.

  5. Correspondence standards

    NASA Technical Reports Server (NTRS)

    1992-01-01

    This revised handbook covers the drafting, preparation, and review of NASA letters, memorandums, informal communications, electronic communications, envelopes and mailing, and classified correspondence. The appendices address specific guidelines for administrator's correspondence, White House and Congressional correspondance, Privacy Act correspondence, and foreign correspondence. Also incorporated as appendices are quick references for forms of address, compound words, and capitalization of words frequently used at NASA.

  6. Population Encoding With Hodgkin–Huxley Neurons

    PubMed Central

    Lazar, Aurel A.

    2013-01-01

    The recovery of (weak) stimuli encoded with a population of Hodgkin–Huxley neurons is investigated. In the absence of a stimulus, the Hodgkin–Huxley neurons are assumed to be tonically spiking. The methodology employed calls for 1) finding an input–output (I/O) equivalent description of the Hodgkin–Huxley neuron and 2) devising a recovery algorithm for stimuli encoded with the I/O equivalent neuron(s). A Hodgkin–Huxley neuron with multiplicative coupling is I/O equivalent with an Integrate-and-Fire neuron with a variable threshold sequence. For bandlimited stimuli a perfect recovery of the stimulus can be achieved provided that a Nyquist-type rate condition is satisfied. A Hodgkin–Huxley neuron with additive coupling and deterministic conductances is first-order I/O equivalent with a Project-Integrate-and-Fire neuron that integrates a projection of the stimulus on the phase response curve. The stimulus recovery is formulated as a spline interpolation problem in the space of finite length bounded energy signals. A Hodgkin–Huxley neuron with additive coupling and stochastic conductances is shown to be first-order I/O equivalent with a Project-Integrate-and-Fire neuron with random thresholds. For stimuli modeled as elements of Sobolev spaces the reconstruction algorithm minimizes a regularized quadratic optimality criterion. Finally, all previous recovery results of stimuli encoded with Hodgkin–Huxley neurons with multiplicative and additive coupling, and deterministic and stochastic conductances are extended to stimuli encoded with a population of Hodgkin–Huxley neurons. PMID:24194625

  7. Correspondencia (Correspondence).

    ERIC Educational Resources Information Center

    Brannan, Robert

    The language of Spanish correspondence possesses particular characteristics that lie somewhere between the everyday conversational style and the more formal literary style. This minicourse contains three lessons intended to enable the student to learn the letter-writing style and to write letters in Spanish. It is also intended to encourage and…

  8. Hugh E. Huxley: the compleat biophysicist.

    PubMed

    Hitchcock-DeGregori, Sarah E; Irving, Thomas C

    2014-10-01

    The sliding filament model of muscle contraction, put forward by Hugh Huxley and Jean Hanson in 1954, is 60 years old in 2014. Formulation of the model and subsequent proof was driven by the pioneering work of Hugh Huxley (1924-2013). We celebrate Huxley's integrative approach to the study of muscle contraction; how he persevered throughout his career, to the end of his life at 89 years, to understand at the molecular level how muscle contracts and develops force. Here we show how his life and work, with its focus on a single scientific problem, had impact far beyond the field of muscle contraction to the benefit of multiple fields of cellular and structural biology. Huxley introduced the use of x-ray diffraction to study the contraction in living striated muscle, taking advantage of the paracrystalline lattice that would ultimately allow understanding contraction in terms of single molecules. Progress required design of instrumentation with ever-increasing spatial and temporal resolution, providing the impetus for the development of synchrotron facilities used for most protein crystallography and muscle studies today. From the time of his early work, Huxley combined electron microscopy and biochemistry to understand and interpret the changes in x-ray patterns. He developed improved electron-microscopy techniques, thin sections and negative staining, that enabled answering major questions relating to the structure and organization of thick and thin filaments in muscle and the interaction of myosin with actin and its regulation. Huxley established that the ATPase domain of myosin forms the crossbridges of thick filaments that bind actin, and introduced the idea that myosin makes discrete steps on actin. These concepts form the underpinning of cellular motility, in particular the study of how myosin, kinesin, and dynein motors move on their actin and tubulin tracks, making Huxley a founder of the field of cellular motility. PMID:25296301

  9. Evolution and Education: Lessons from Thomas Huxley

    NASA Astrophysics Data System (ADS)

    Lyons, Sherrie Lynne

    2010-05-01

    Thomas Huxley more than anyone else was responsible for disseminating Darwin’s theory in the western world and maintained that investigating the history of life should be regarded as a purely scientific question free of theological speculation. The content and rhetorical strategy of Huxley’s defense of evolution is analyzed. Huxley argued that the classification of humans should be determined independent of any theories of origination of species. Besides providing evidence that demonstrated the close relationship between apes and humans, he also argued that a pithecoid ancestry in no way degraded humankind. In his broader defense of evolution he drew on his agnosticism to define what science could and could not explain. Theology made empirical claims and needed to be subject to the same standards of evidence as scientific claims. He maintained that even most scientific objections to evolution were religiously based. The objections to the theory fundamentally remain the same as in the nineteenth century and much can be learned from Huxley to develop effective strategies for educating the public about evolution. Huxley’s own scientific articles as well as his popular writings provide numerous examples that could be harnessed not only for the teaching of evolution, but also for understanding science as a process.

  10. How a Neurologically Integrated Approach Which Teaches Sound-Symbol Correspondence and Legible Letter Formations Impacts At-Risk First Graders

    ERIC Educational Resources Information Center

    Shaw, Donita Massengill; Sundberg, Mary Lou

    2008-01-01

    The setting of this study took place in an inner city. The purpose was to determine the effectiveness of a neurologically integrated approach in teaching 43 at-risk pre-first graders their letter sounds and formations during 45-50 hours of summer school. There were four sequential phases to teaching this alphabetic approach: imagery, auditory,…

  11. Letters, We Get Letters.

    ERIC Educational Resources Information Center

    Linton, Gretchen

    1997-01-01

    To aid teachers and students in their quest for information, an education specialist at an aquarium offers tips for organizing field trips, discusses home pages and search engines on the Internet, and gives detailed instructions for writing letters to institutions for information. Suggestions include writing joint letters if many students have the…

  12. The Hodgkin-Huxley Heritage: From Channels to Circuits

    PubMed Central

    Catterall, William A.; Raman, Indira M.; Robinson, Hugh P. C.; Sejnowski, Terrence J.; Paulsen, Ole

    2012-01-01

    The Hodgkin-Huxley studies of the action potential, published 60 years ago, are a central pillar of modern neuroscience research, ranging from molecular investigations of the structural basis of ion channel function to the computational implications at circuit level. In this Symposium Review, we aim to demonstrate the ongoing impact of Hodgkin’s and Huxley’s ideas. The Hodgkin-Huxley model established a framework in which to describe the structural and functional properties of ion channels, including the mechanisms of ion permeation, selectivity, and gating. At a cellular level, the model is used to understand the conditions that control both the rate and timing of action potentials, essential for neural encoding of information. Finally, the Hodgkin-Huxley formalism is central to computational neuroscience to understand both neuronal integration and circuit level information processing, and how these mechanisms might have evolved to minimize energy cost. PMID:23055474

  13. Challenging normative orthodoxies in depression: Huxley's Utopia or Dante's Inferno?

    PubMed

    Cutcliffe, John R; Lakeman, Richard

    2010-04-01

    Although there appears to be a widespread consensus that depression is a ubiquitous human experience, definitions of depression, its prevalence, and how mental health services respond to it have changed significantly over time, particularly during recent decades. Epistemological limitations notwithstanding, it is now estimated that approximately 121 million people experience depression. At the same time, it should be acknowledged that the last two decades have seen the widespread acceptance of depression as a chemical imbalance and a massive corresponding increase in the prescription of antidepressants, most notably of selective serotonin reuptake inhibitors (SSRIs). However, questions have been raised about the effectiveness and iatrogenic side effects of antidepressants; related questions have also been asked about whose interests are served by the marketing and sales of these drugs. Accordingly, this article attempts to problematize the normative orthodoxy concerning depression and creates a "space" in which an alternative can be articulated and enacted. In so doing, the article finds that the search for a world where the automatic response to depression is a pharmacological intervention not only ignores the use of alternative efficacious treatment options but may also inhibit the persons' chance to explore the meaning of their experience and thus prevent people from individual growth and personal development. Interestingly, in worlds analogous to this pharmacologically induced depression-free state, such as utopias like that in Huxley's Brave New World, no "properly conditioned citizen" is depressed or suicidal. Yet, in the same Brave New World, no one is free to suffer, to be different, or crucially, to be independent.

  14. A Framed Letter.

    ERIC Educational Resources Information Center

    Chiodo, Beverly A.; Hatcher, Barbara

    1997-01-01

    In a correspondence class, students were asked to name a hero or heroine and list their qualities. Many named parents or grandparents, and the teacher wrote letters telling them what the students had said about them. The letter was to convey the student's respect and appreciation, something they often find difficult to do in person. (JOW)

  15. Statistical mechanics of the Huxley-Simmons model

    NASA Astrophysics Data System (ADS)

    Caruel, M.; Truskinovsky, L.

    2016-06-01

    The chemomechanical model of Huxley and Simmons (HS) [A. F. Huxley and R. M. Simmons, Nature 233, 533 (1971), 10.1038/233533a0] provides a paradigmatic description of mechanically induced collective conformational changes relevant in a variety of biological contexts, from muscles power stroke and hair cell gating to integrin binding and hairpin unzipping. We develop a statistical mechanical perspective on the HS model by exploiting a formal analogy with a paramagnetic Ising model. We first study the equilibrium HS model with a finite number of elements and compute explicitly its mechanical and thermal properties. To model kinetics, we derive a master equation and solve it for several loading protocols. The developed formalism is applicable to a broad range of allosteric systems with mean-field interactions.

  16. Correspondence: A Medium Rediscovered.

    ERIC Educational Resources Information Center

    Dilworth, Collett B., Jr.; Wilde, Pat

    Two English teachers, one in North Carolina and one in Missouri, structured a correspondence project for their senior English classes so that 60 students at each school exchanged personal letters once each week during the semester. The students responded to the project with an interest and drive that overshadowed their interest in the normal…

  17. From the Hodgkin-Huxley axon to the virtual heart

    PubMed Central

    Noble, Denis

    2007-01-01

    Experimentally based models of the heart have been developed since 1960, starting with the discovery and modelling of potassium channels. The early models were based on extensions of the Hodgkin–Huxley nerve impulse equations. The first models including calcium balance and signalling were made in the 1980s and have now reached a high degree of physiological detail. During the 1990s these cell models have been incorporated into anatomically detailed tissue and organ models to create the first virtual organ, the Virtual Heart. With over 40 years of interaction between simulation and experiment, the models are now sufficiently refined to begin to be of use in drug development. PMID:17023502

  18. Memristor, Hodgkin-Huxley, and edge of chaos.

    PubMed

    Chua, Leon

    2013-09-27

    From a pedagogical point of view, the memristor is defined in this tutorial as any 2-terminal device obeying a state-dependent Ohm's law. This tutorial also shows that from an experimental point of view, the memristor can be defined as any 2-terminal device that exhibits the fingerprints of 'pinched' hysteresis loops in the v-i plane. It also shows that memristors endowed with a continuum of equilibrium states can be used as non-volatile analog memories. This tutorial shows that memristors span a much broader vista of complex phenomena and potential applications in many fields, including neurobiology. In particular, this tutorial presents toy memristors that can mimic the classic habituation and LTP learning phenomena. It also shows that sodium and potassium ion-channel memristors are the key to generating the action potential in the Hodgkin-Huxley equations, and that they are the key to resolving several unresolved anomalies associated with the Hodgkin-Huxley equations. This tutorial ends with an amazing new result derived from the new principle of local activity, which uncovers a minuscule life-enabling 'Goldilocks zone', dubbed the edge of chaos, where complex phenomena, including creativity and intelligence, may emerge. From an information processing perspective, this tutorial shows that synapses are locally-passive memristors, and that neurons are made of locally-active memristors.

  19. Memristor, Hodgkin-Huxley, and edge of chaos.

    PubMed

    Chua, Leon

    2013-09-27

    From a pedagogical point of view, the memristor is defined in this tutorial as any 2-terminal device obeying a state-dependent Ohm's law. This tutorial also shows that from an experimental point of view, the memristor can be defined as any 2-terminal device that exhibits the fingerprints of 'pinched' hysteresis loops in the v-i plane. It also shows that memristors endowed with a continuum of equilibrium states can be used as non-volatile analog memories. This tutorial shows that memristors span a much broader vista of complex phenomena and potential applications in many fields, including neurobiology. In particular, this tutorial presents toy memristors that can mimic the classic habituation and LTP learning phenomena. It also shows that sodium and potassium ion-channel memristors are the key to generating the action potential in the Hodgkin-Huxley equations, and that they are the key to resolving several unresolved anomalies associated with the Hodgkin-Huxley equations. This tutorial ends with an amazing new result derived from the new principle of local activity, which uncovers a minuscule life-enabling 'Goldilocks zone', dubbed the edge of chaos, where complex phenomena, including creativity and intelligence, may emerge. From an information processing perspective, this tutorial shows that synapses are locally-passive memristors, and that neurons are made of locally-active memristors. PMID:23999613

  20. Memristor, Hodgkin-Huxley, and Edge of Chaos

    NASA Astrophysics Data System (ADS)

    Chua, Leon

    2013-09-01

    From a pedagogical point of view, the memristor is defined in this tutorial as any 2-terminal device obeying a state-dependent Ohm’s law. This tutorial also shows that from an experimental point of view, the memristor can be defined as any 2-terminal device that exhibits the fingerprints of ‘pinched’ hysteresis loops in the v-i plane. It also shows that memristors endowed with a continuum of equilibrium states can be used as non-volatile analog memories. This tutorial shows that memristors span a much broader vista of complex phenomena and potential applications in many fields, including neurobiology. In particular, this tutorial presents toy memristors that can mimic the classic habituation and LTP learning phenomena. It also shows that sodium and potassium ion-channel memristors are the key to generating the action potential in the Hodgkin-Huxley equations, and that they are the key to resolving several unresolved anomalies associated with the Hodgkin-Huxley equations. This tutorial ends with an amazing new result derived from the new principle of local activity, which uncovers a minuscule life-enabling ‘Goldilocks zone’, dubbed the edge of chaos, where complex phenomena, including creativity and intelligence, may emerge. From an information processing perspective, this tutorial shows that synapses are locally-passive memristors, and that neurons are made of locally-active memristors.

  1. A Stimulus Sampling Theory of Letter Identity and Order

    ERIC Educational Resources Information Center

    Norris, Dennis; Kinoshita, Sachiko; van Casteren, Maarten

    2010-01-01

    Early on during word recognition, letter positions are not accurately coded. Evidence for this comes from transposed-letter (TL) priming effects, in which letter strings generated by transposing two adjacent letters (e.g., "jugde") produce large priming effects, more than primes with the letters replaced in the corresponding position (e.g.,…

  2. Response of autaptic Hodgkin-Huxley neuron with noise to subthreshold sinusoidal signals

    NASA Astrophysics Data System (ADS)

    Wang, Hengtong; Chen, Yong

    2016-11-01

    In this work, we investigated the response of a stochastic Hodgkin-Huxley (HH) neuron with an autapse to subthreshold sinusoidal signals. It is found that the autapse not only adjusts the stochastic responses, but also improves the detection of subthreshold signals. In the case of weak noise, the autapse facilitates the response of neuron to the subthreshold sinusoidal signals with a small parameter region in tdelay- ω space. The increased noise intensity enlarges this parameter region and increases the corresponding response frequency in such range. As the autaptic intensity increases, however, this parameter region shrunks. We also observed that there is an optimal range of the delay time of autapse, within which the stochastic HH neuron fires action potentials with high frequency. The corresponding response spike train for the optimal delay time is nearly a regular sequence with the interspike intervals approximated to the delay time. The current results reveal a novel resonance phenomenon facilitated by autapse, named autaptic delay-induced coherence resonance.

  3. Hodgkin–Huxley revisited: reparametrization and identifiability analysis of the classic action potential model with approximate Bayesian methods

    PubMed Central

    Daly, Aidan C.; Holmes, Chris

    2015-01-01

    As cardiac cell models become increasingly complex, a correspondingly complex ‘genealogy’ of inherited parameter values has also emerged. The result has been the loss of a direct link between model parameters and experimental data, limiting both reproducibility and the ability to re-fit to new data. We examine the ability of approximate Bayesian computation (ABC) to infer parameter distributions in the seminal action potential model of Hodgkin and Huxley, for which an immediate and documented connection to experimental results exists. The ability of ABC to produce tight posteriors around the reported values for the gating rates of sodium and potassium ion channels validates the precision of this early work, while the highly variable posteriors around certain voltage dependency parameters suggests that voltage clamp experiments alone are insufficient to constrain the full model. Despite this, Hodgkin and Huxley's estimates are shown to be competitive with those produced by ABC, and the variable behaviour of posterior parametrized models under complex voltage protocols suggests that with additional data the model could be fully constrained. This work will provide the starting point for a full identifiability analysis of commonly used cardiac models, as well as a template for informative, data-driven parametrization of newly proposed models. PMID:27019736

  4. Hodgkin-Huxley revisited: reparametrization and identifiability analysis of the classic action potential model with approximate Bayesian methods.

    PubMed

    Daly, Aidan C; Gavaghan, David J; Holmes, Chris; Cooper, Jonathan

    2015-12-01

    As cardiac cell models become increasingly complex, a correspondingly complex 'genealogy' of inherited parameter values has also emerged. The result has been the loss of a direct link between model parameters and experimental data, limiting both reproducibility and the ability to re-fit to new data. We examine the ability of approximate Bayesian computation (ABC) to infer parameter distributions in the seminal action potential model of Hodgkin and Huxley, for which an immediate and documented connection to experimental results exists. The ability of ABC to produce tight posteriors around the reported values for the gating rates of sodium and potassium ion channels validates the precision of this early work, while the highly variable posteriors around certain voltage dependency parameters suggests that voltage clamp experiments alone are insufficient to constrain the full model. Despite this, Hodgkin and Huxley's estimates are shown to be competitive with those produced by ABC, and the variable behaviour of posterior parametrized models under complex voltage protocols suggests that with additional data the model could be fully constrained. This work will provide the starting point for a full identifiability analysis of commonly used cardiac models, as well as a template for informative, data-driven parametrization of newly proposed models. PMID:27019736

  5. Letter Imperfect

    ERIC Educational Resources Information Center

    Kramer, Stephen

    2003-01-01

    In this essay, the author, a 5th-grade teacher, questions how well a standardized test can measure his students. This article presents a letter he wrote for the Washington state science test scorer regarding his students' test scores. He shares stories about some of the students in his class. He points out that tests can turn out to be more like…

  6. Models of Discourse in the Letter of Complaint

    ERIC Educational Resources Information Center

    Hartford, Beverly; Mahboob, Ahmar

    2004-01-01

    In both the Outer Circle and the Expanding Circle countries, books which provide examples of letters written in English and guidelines for writing these letters are available for students, business people, and any others who have an interest or need for writing such letters. These model letters are not only for business correspondence, but also…

  7. [Thomas H.Huxley--the naval doctor who became Darwin's bulldog].

    PubMed

    Hauge, A

    2000-12-10

    Thomas H. Huxley (1825-1895) was an English physician and biologist who had a deep impact on the Victorian age. More than any other at his time he introduced scientifically based values. As a member of London's school board he brought science into the curriculum, encouraging school-children to ask questions and to make their own observations. Huxley came from a lower middle class family with little money. By sheer determination and hard work he managed to get a medical education at Charing Cross Hospital Medical School. He then obtained a posting on H.M.S. Rattlesnake, which gave him a chance to explore the southern seas and to study marine species. The results were published by the Royal Society of which Huxley became a member at the age of 26, and later its president. After several years of uncertainty he secured a position at the Royal School of Mines, which he transformed into the Imperial College of Science. He was a prolific scientist with wide interests, doing valuable work in paleontology, taxonomy and ethnology. Huxley wrote numerous essays on philosophy and scientific subjects. He coined the word agnostic to explain his attitude to Christian dogma. His style was clear and direct, and his essays still read very well. However, Huxley is now mostly, perhaps unfairly, remembered for his defence of Darwin's theory of evolution. In his book Evidence as to man's place in nature, Huxley, in contrast to Darwin, deals with the evolution of humans, mainly based on comparative anatomy. Huxley advocated a firmly held belief that scientific truths will have a liberating effect on the minds of men. His lectures on scientific subjects attracted large audiences of people who had not had the benefit of a higher education.

  8. [Thomas H.Huxley--the naval doctor who became Darwin's bulldog].

    PubMed

    Hauge, A

    2000-12-10

    Thomas H. Huxley (1825-1895) was an English physician and biologist who had a deep impact on the Victorian age. More than any other at his time he introduced scientifically based values. As a member of London's school board he brought science into the curriculum, encouraging school-children to ask questions and to make their own observations. Huxley came from a lower middle class family with little money. By sheer determination and hard work he managed to get a medical education at Charing Cross Hospital Medical School. He then obtained a posting on H.M.S. Rattlesnake, which gave him a chance to explore the southern seas and to study marine species. The results were published by the Royal Society of which Huxley became a member at the age of 26, and later its president. After several years of uncertainty he secured a position at the Royal School of Mines, which he transformed into the Imperial College of Science. He was a prolific scientist with wide interests, doing valuable work in paleontology, taxonomy and ethnology. Huxley wrote numerous essays on philosophy and scientific subjects. He coined the word agnostic to explain his attitude to Christian dogma. His style was clear and direct, and his essays still read very well. However, Huxley is now mostly, perhaps unfairly, remembered for his defence of Darwin's theory of evolution. In his book Evidence as to man's place in nature, Huxley, in contrast to Darwin, deals with the evolution of humans, mainly based on comparative anatomy. Huxley advocated a firmly held belief that scientific truths will have a liberating effect on the minds of men. His lectures on scientific subjects attracted large audiences of people who had not had the benefit of a higher education. PMID:11215943

  9. Principal Dynamic Mode Analysis of the Hodgkin–Huxley Equations

    PubMed Central

    Eikenberry, Steffen E.; Marmarelis, Vasilis Z.

    2015-01-01

    We develop an autoregressive model framework based on the concept of Principal Dynamic Modes (PDMs) for the process of action potential (AP) generation in the excitable neuronal membrane described by the Hodgkin–Huxley (H–H) equations. The model's exogenous input is injected current, and whenever the membrane potential output exceeds a specified threshold, it is fed back as a second input. The PDMs are estimated from the previously developed Nonlinear Autoregressive Volterra (NARV) model, and represent an efficient functional basis for Volterra kernel expansion. The PDM-based model admits a modular representation, consisting of the forward and feedback PDM bases as linear filterbanks for the exogenous and autoregressive inputs, respectively, whose outputs are then fed to a static nonlinearity composed of polynomials operating on the PDM outputs and cross-terms of pair-products of PDM outputs. A two-step procedure for model reduction is performed: first, influential subsets of the forward and feedback PDM bases are identified and selected as the reduced PDM bases. Second, the terms of the static nonlinearity are pruned. The first step reduces model complexity from a total of 65 coefficients to 27, while the second further reduces the model coefficients to only eight. It is demonstrated that the performance cost of model reduction in terms of out-of-sample prediction accuracy is minimal. Unlike the full model, the eight coefficient pruned model can be easily visualized to reveal the essential system components, and thus the data-derived PDM model can yield insight into the underlying system structure and function. PMID:25630480

  10. Stimulus-dependent refractoriness in the Frankenhaeuser-Huxley model.

    PubMed

    Morse, R P; Allingham, D; Stocks, N G

    2015-10-01

    Phenomenological neural models, such as the leaky integrate-and-fire model, normally have a fixed refractory time-course that is independent of the stimulus. The recovery of threshold following an action potential is typically based on physiological experiments that use a two-pulse paradigm in which the first pulse is suprathreshold and causes excitation and the second pulse is used to determine the threshold at various intervals following the first. In such experiments, the nerve is completely unstimulated between the two pulses. This contrasts the receptor stimuli in normal physiological systems and the electrical stimuli used by cochlear implants and other neural prostheses. A numerical study of the Frankenhaeuser-Huxley conductance-based model of nerve fibre was therefore undertaken to investigate the effect of stimulation on refractoriness. We found that the application of a depolarizing stimulus during the later part of what is classically regarded as the absolute refractory period could effectively prolong the absolute refractory period, while leaving the refractory time-constants and other refractory parameters largely unaffected. Indeed, long depolarizing pulses, which would have been suprathreshold if presented to a resting nerve fibre, appeared to block excitation indefinitely. Stimulation during what is classically regarded as the absolute refractory period can therefore greatly affect the temporal response of a nerve. We conclude that the classical definition of absolute refractory period should be refined to include only the initial period following an action potential when an ongoing stimulus would not affect threshold; this period was found to be about half as long as the classical absolute refractory period. We further conclude that the stimulus-dependent nature of the relative refractory period must be considered when developing a phenomenological nerve model for complex stimuli.

  11. Stimulus-dependent refractoriness in the Frankenhaeuser-Huxley model.

    PubMed

    Morse, R P; Allingham, D; Stocks, N G

    2015-10-01

    Phenomenological neural models, such as the leaky integrate-and-fire model, normally have a fixed refractory time-course that is independent of the stimulus. The recovery of threshold following an action potential is typically based on physiological experiments that use a two-pulse paradigm in which the first pulse is suprathreshold and causes excitation and the second pulse is used to determine the threshold at various intervals following the first. In such experiments, the nerve is completely unstimulated between the two pulses. This contrasts the receptor stimuli in normal physiological systems and the electrical stimuli used by cochlear implants and other neural prostheses. A numerical study of the Frankenhaeuser-Huxley conductance-based model of nerve fibre was therefore undertaken to investigate the effect of stimulation on refractoriness. We found that the application of a depolarizing stimulus during the later part of what is classically regarded as the absolute refractory period could effectively prolong the absolute refractory period, while leaving the refractory time-constants and other refractory parameters largely unaffected. Indeed, long depolarizing pulses, which would have been suprathreshold if presented to a resting nerve fibre, appeared to block excitation indefinitely. Stimulation during what is classically regarded as the absolute refractory period can therefore greatly affect the temporal response of a nerve. We conclude that the classical definition of absolute refractory period should be refined to include only the initial period following an action potential when an ongoing stimulus would not affect threshold; this period was found to be about half as long as the classical absolute refractory period. We further conclude that the stimulus-dependent nature of the relative refractory period must be considered when developing a phenomenological nerve model for complex stimuli. PMID:26187096

  12. Correspondence analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Correspondence analysis is a powerful exploratory multivariate technique for categorical variables with many levels. It is a data analysis tool that characterizes associations between levels of 2 or more categorical variables using graphical representations of the information in a contingency table...

  13. Letter: Meyerhofer

    SciTech Connect

    Mackinnon, A J

    2011-01-06

    This letter confirms that the Laboratory for Laser Energetics (LLE) was an important part of the FY10 NIF Polar Drive Exploding Pusher experiments on the National Ignition Facility (NIF). These experiments were designed by LLE to produce requested neutron yields to calibrate and qualify nuclear diagnostics. LLE built a deuterium-tritium filling system for the glass shells and provided them to LLNL for mounting. In FY10, four exploding pusher implosions were performed with measured neutron yields within a factor of two of requested and ion temperatures within 20% of requested. These implosions are proving to be an ideal platform for commissioning the nuclear diagnostic suite on the NIF and are achieving all of the objectives planned for this campaign.

  14. T.H. Huxley's criticism of German cell theory: an epigenetic and physiological interpretation of cell structure.

    PubMed

    Richmond, M L

    2000-01-01

    In 1853, the young Thomas Henry Huxley published a long review of German cell theory in which he roundly criticized the basic tenets of the Schleiden-Schwann model of the cell. Although historians of cytology have dismissed Huxley's criticism as based on an erroneous interpretation of cell physiology, the review is better understood as a contribution to embryology. "The Cell-theory" presents Huxley's "epigenetic" interpretation of histological organization emerging from changes in the protoplasm to replace the "preformationist" cell theory of Schleiden and Schwann (as modified by Albert von Kolliker), which posited the nucleus as the seat of organic vitality. Huxley's views influenced a number of British biologists, who continued to oppose German cell theory well into the twentieth century. Yet Huxley was pivotal in introducing the new German program of "scientific zoology" to Britain in the early 1850s, championing its empiricist methodology as a means to enact broad disciplinary and institutional reforms in British natural history. PMID:11640226

  15. The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

    PubMed

    Lightman, Bernard

    2016-08-01

    As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system. PMID:26751794

  16. Tunicates: exploring the sea shores and roaming the open ocean. A tribute to Thomas Huxley

    PubMed Central

    Lemaire, Patrick; Piette, Jacques

    2015-01-01

    This review is a tribute to the remarkable contributions of Thomas Huxley to the biology of tunicates, the likely sister group of vertebrates. In 1851, the great biologist and philosopher published two landmark papers on pelagic tunicates in the Philosophical Transactions of the Royal Society. They were dedicated to the description of the adult anatomy and life cycle of thaliaceans and appendicularians, the pelagic relatives of ascidians. In the first part of this review, we discuss the novel anatomical observations and evolutionary hypotheses made by Huxley, which would have a lasting influence on tunicate biology. We also briefly comment on the more philosophical reflections of Huxley on individuality. In the second part, we stress the originality and relevance of past and future studies of tunicates in the resolution of major biological issues. In particular, we focus on the complex relationship between genotype and phenotype and the phenomenon of developmental system drift. We propose that more than 150 years after Huxley's papers, tunicate embryos are still worth studying in their own right, independently of their evolutionary proximity to vertebrates, as they provide original and crucial insights into the process of animal evolution. Tunicates are still at the forefront of biological research. PMID:26085517

  17. The "History" of Victorian Scientific Naturalism: Huxley, Spencer and the "End" of natural history.

    PubMed

    Lightman, Bernard

    2016-08-01

    As part of their defence of evolutionary theory, T. H. Huxley and Herbert Spencer argued that natural history was no longer a legitimate scientific discipline. They outlined a secularized concept of life from biology to argue for the validity of naturalism. Despite their support for naturalism, they offered two different responses to the decline of natural history. Whereas Huxley emphasized the creation of a biological discipline, and all that that entailed, Spencer was more concerned with constructing an entire intellectual system based on the idea of evolution. In effect, Spencer wanted to create a new scientific worldview based on evolutionary theory. This had consequences for their understanding of human history, especially of how science had evolved through the ages. It affected their conceptions of human agency, contingency, and directionality in history. Examining Huxley's and Spencer's responses to the "end" of natural history reveals some of the deep divisions within scientific naturalism and the inherent problems of naturalism in general. Whereas Huxley chose to separate the natural and the historical, Spencer opted to fuse them into a single system.

  18. Einstein/Roosevelt Letters: A Unit.

    ERIC Educational Resources Information Center

    Bodle, Walter S.

    1985-01-01

    The letters in this unit of study intended for secondary students are facsimile reproductions of the correspondence between Albert Einstein and President Roosevelt on the possibility of constructing an atomic bomb. Classroom activities are also suggested. (RM)

  19. Perceptual-Motor Complexity of Printed and Cursive Letters.

    ERIC Educational Resources Information Center

    Meulenbroek, Ruud G. J.; Van Galen, Gerard P.

    1990-01-01

    Seventy-five Dutch elementary school students wrote letters of a cursive alphabet after presentation of printed and cursive letters. Analysis revealed that spatial ambiguity, allographic variability, contextual ambiguity, and letter frequency are determinants of the time needed by children for perceiving printed and producing corresponding cursive…

  20. Controlling the onset of Hopf bifurcation in the Hodgkin-Huxley model.

    PubMed

    Xie, Yong; Chen, Luonan; Kang, Yan Mei; Aihara, Kazuyuki

    2008-06-01

    It is a challenging problem to establish safe and simple therapeutic methods for various complicated diseases of the nervous system, particularly dynamical diseases such as epilepsy, Alzheimer's disease, and Parkinson's disease. From the viewpoint of nonlinear dynamical systems, a dynamical disease can be considered to be caused by a bifurcation induced by a change in the values of one or more regulating parameter. Therefore, the theory of bifurcation control may have potential applications in the diagnosis and therapy of dynamical diseases. In this study, we employ a washout filter-aided dynamic feedback controller to control the onset of Hopf bifurcation in the Hodgkin-Huxley (HH) model. Specifically, by the control scheme, we can move the Hopf bifurcation to a desired point irrespective of whether the corresponding steady state is stable or unstable. In other words, we are able to advance or delay the Hopf bifurcation, so as to prevent it from occurring in a certain range of the externally applied current. Moreover, we can control the criticality of the bifurcation and regulate the oscillation amplitude of the bifurcated limit cycle. In the controller, there are only two terms: the linear term and the nonlinear cubic term. We show that while the former determines the location of the Hopf bifurcation, the latter regulates the criticality of the Hopf bifurcation. According to the conditions of the occurrence of Hopf bifurcation and the bifurcation stability coefficient, we can analytically deduce the linear term and the nonlinear cubic term, respectively. In addition, we also show that mixed-mode oscillations (MMOs), featuring slow action potential generation, which are frequently observed in both experiments and models of chemical and biological systems, appear in the controlled HH model. It is well known that slow firing rates in single neuron models could be achieved only by type-I neurons. However, the controlled HH model is still classified as a type

  1. Controlling the onset of Hopf bifurcation in the Hodgkin-Huxley model

    NASA Astrophysics Data System (ADS)

    Xie, Yong; Chen, Luonan; Kang, Yan Mei; Aihara, Kazuyuki

    2008-06-01

    It is a challenging problem to establish safe and simple therapeutic methods for various complicated diseases of the nervous system, particularly dynamical diseases such as epilepsy, Alzheimer’s disease, and Parkinson’s disease. From the viewpoint of nonlinear dynamical systems, a dynamical disease can be considered to be caused by a bifurcation induced by a change in the values of one or more regulating parameter. Therefore, the theory of bifurcation control may have potential applications in the diagnosis and therapy of dynamical diseases. In this study, we employ a washout filter-aided dynamic feedback controller to control the onset of Hopf bifurcation in the Hodgkin-Huxley (HH) model. Specifically, by the control scheme, we can move the Hopf bifurcation to a desired point irrespective of whether the corresponding steady state is stable or unstable. In other words, we are able to advance or delay the Hopf bifurcation, so as to prevent it from occurring in a certain range of the externally applied current. Moreover, we can control the criticality of the bifurcation and regulate the oscillation amplitude of the bifurcated limit cycle. In the controller, there are only two terms: the linear term and the nonlinear cubic term. We show that while the former determines the location of the Hopf bifurcation, the latter regulates the criticality of the Hopf bifurcation. According to the conditions of the occurrence of Hopf bifurcation and the bifurcation stability coefficient, we can analytically deduce the linear term and the nonlinear cubic term, respectively. In addition, we also show that mixed-mode oscillations (MMOs), featuring slow action potential generation, which are frequently observed in both experiments and models of chemical and biological systems, appear in the controlled HH model. It is well known that slow firing rates in single neuron models could be achieved only by type-I neurons. However, the controlled HH model is still classified as a type

  2. How the Hodgkin–Huxley equations inspired the Cardiac Physiome Project

    PubMed Central

    Noble, Denis; Garny, Alan; Noble, Penelope J

    2012-01-01

    Early modelling of cardiac cells (1960–1980) was based on extensions of the Hodgkin–Huxley nerve axon equations with additional channels incorporated, but after 1980 it became clear that processes other than ion channel gating were also critical in generating electrical activity. This article reviews the development of models representing almost all cell types in the heart, many different species, and the software tools that have been created to facilitate the cardiac Physiome Project. PMID:22473779

  3. Past as Prediction: Newcomb, Huxley, The Eclipse of Thales, and The Power of Science

    NASA Astrophysics Data System (ADS)

    Stanley, Matthew

    2009-12-01

    The ancient eclipse of Thales was an important, if peculiar, focus of scientific attention in the 19th century. Victorian-era astronomers first used it as data with which to calibrate their lunar theories, but its status became strangely malleable as the century progressed. The American astronomer Simon Newcomb re-examined the eclipse and rejected it as the basis for lunar theory. But strangely, it was the unprecedented accuracy of Newcomb's calculations that led the British biologist T.H. Huxley to declare the eclipse to be the quintessential example of the power of science. Huxley argued that astronomy's ability to create "retrospective prophecy” showed how scientific reasoning was superior to religion (and incidentally, helped support Darwin's theories). Both Newcomb and Huxley declared that prediction (of past and future) was what gave science its persuasive power. The eclipse of Thales's strange journey through Victorian astronomy reveals how these two influential scientists made the case for the social and cultural authority of science.

  4. Letter to jane addams.

    PubMed

    Bloom, M

    1995-06-01

    This letter, written to one of the founding figures in social work, draws parallels between primary prevention at the beginning and the end of the twentieth century. As expected, the letter remains unanswered.

  5. Exploring the Role of Mechanotransduction Activation and Adaptation Kinetics in Hair Cell Filtering Using a Hodgkin-Huxley Approach

    NASA Astrophysics Data System (ADS)

    Wells, Gregg B.; Ricci, Anthony J.

    2011-11-01

    In the auditory system, mechanotransduction occurs in the hair cell sensory hair bundle and is the first major step in the translation of mechanical energy into electrical. Tonotopic variations in the activation kinetics of this process are posited to provide a low pass filter to the input. An adaptation process, also associated with mechanotransduction, is postulated to provide a high pass filter to the input in a tonotopic manner. Together a bandpass filter is created at the hair cell input. Corresponding mechanical components to both activation and adaptation are also suggested to be involved in generating cochlear amplification. A paradox to this story is that hair cells where the mechanotransduction properties are most robust possess an intrinsic electrical resonance mechanism proposed to account for all required tuning and amplification. A simple Hodgkin-Huxley type model is presented to attempt to determine the role of the activation and adaptation kinetics in further tuning hair cells that exhibit electrical resonance. Results further support that steady state mechanotransduction properties are critical for setting the resting potential of the hair cell while the kinetics of activation and adaptation are important for sharpening tuning around the characteristic frequency of the hair cell.

  6. Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs.

    PubMed

    Hübel, Niklas; Dahlem, Markus A

    2014-12-01

    The classical Hodgkin-Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.

  7. Dynamics from Seconds to Hours in Hodgkin-Huxley Model with Time-Dependent Ion Concentrations and Buffer Reservoirs

    PubMed Central

    Hübel, Niklas; Dahlem, Markus A.

    2014-01-01

    The classical Hodgkin-Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively. PMID:25474648

  8. RED-LETTER DAYS

    EPA Science Inventory

    The word "red-letter" is an adjective meaning "of special significance." It's origin is from the practice of marking Christian holy days in red letters on calendars. The "red-letter days" to which I refer occurred while I was a graduate student of ...

  9. All About Letters.

    ERIC Educational Resources Information Center

    Post Office Dept., Washington, DC.

    This booklet, designed to promote the letter writing habit, provides information about writing letters in a variety of situations. It is divided into several short sections with illustrations. Reasons to write letters and postcards are offered by several authors and celebrites including Stevie Wonder, Darryl Stingley, and "Dear Abby." Addresses…

  10. Correspondence from Mathematicians.

    ERIC Educational Resources Information Center

    Horn, Jennifer; Zamierowski, Amy; Barger, Rita

    2000-01-01

    Describes a mathematics history project to incorporate research skills with discovering the origins of familiar mathematical concepts. Uses a personal letter from a mathematician about a discovery. (KHR)

  11. Learning to write letters: examination of student and letter factors.

    PubMed

    Puranik, Cynthia S; Petscher, Yaacov; Lonigan, Christopher J

    2014-12-01

    Learning to write the letters of the alphabet is an important part of learning how to write conventionally. In this study, we investigated critical factors in the development of letter-writing skills using exploratory item response models to simultaneously account for variance in responses due to differences between students and between letters. Letter-writing skills were assessed in 415 preschool children aged 3 to 5 years. At the student level, we examined the contribution of letter-name knowledge, letter-sound knowledge, and phonological awareness to letter-writing skills. At the letter level, we examined seven intrinsic and extrinsic factors in understanding how preschool children learn to write alphabet letters: first letter of name, letters in name, letter order, textual frequency, number of strokes, symmetry, and letter type. Results indicated that variation in letter-writing skills was accounted for more by differences between students rather than by differences between letters, with most of the variability accounted for by letter-name knowledge and age. Although significant, the contribution of letter-sound knowledge and phonological awareness was relatively small. Student-level mechanisms underlying the acquisition of letter-writing skills are similar to the mechanisms underlying the learning of letter sounds. However, letter characteristics, which appear to play a major role in the learning of letter names and letter sounds, did not appear to influence learning how to write letters in a substantial way. The exception was if the letter was in the child's name. PMID:25181463

  12. Learning to write letters: examination of student and letter factors.

    PubMed

    Puranik, Cynthia S; Petscher, Yaacov; Lonigan, Christopher J

    2014-12-01

    Learning to write the letters of the alphabet is an important part of learning how to write conventionally. In this study, we investigated critical factors in the development of letter-writing skills using exploratory item response models to simultaneously account for variance in responses due to differences between students and between letters. Letter-writing skills were assessed in 415 preschool children aged 3 to 5 years. At the student level, we examined the contribution of letter-name knowledge, letter-sound knowledge, and phonological awareness to letter-writing skills. At the letter level, we examined seven intrinsic and extrinsic factors in understanding how preschool children learn to write alphabet letters: first letter of name, letters in name, letter order, textual frequency, number of strokes, symmetry, and letter type. Results indicated that variation in letter-writing skills was accounted for more by differences between students rather than by differences between letters, with most of the variability accounted for by letter-name knowledge and age. Although significant, the contribution of letter-sound knowledge and phonological awareness was relatively small. Student-level mechanisms underlying the acquisition of letter-writing skills are similar to the mechanisms underlying the learning of letter sounds. However, letter characteristics, which appear to play a major role in the learning of letter names and letter sounds, did not appear to influence learning how to write letters in a substantial way. The exception was if the letter was in the child's name.

  13. Mud, Blood, and Bullet Holes: Teaching History with War Letters

    ERIC Educational Resources Information Center

    Carroll, Andrew

    2013-01-01

    From handwritten letters of the American Revolution to typed emails from Iraq and Afghanistan, correspondence from U.S. troops offers students deep insight into the specific conflicts and experiences of soldiers. Over 100,000 correspondences have been donated to the Legacy Project, a national initiative launched in 1998 to preserve war letters by…

  14. Huxley's Model for Muscle Contraction Revisited: The Importance of Microscopic Reversibility.

    PubMed

    Astumian, R Dean

    2015-01-01

    Andrew Huxley's model for muscle contraction is the first mechanistic description of how an energy-providing chemical reaction, ATP hydrolysis, can be coupled by a molecule (myosin) to do work in the environment in a cyclic process. The model was originally used to fit experimentally obtained force vs velocity curves, and has served as a paradigm for understanding mechanochemical coupling ever since. Despite the remarkable success in fitting kinetic data, Huxley's model is thermodynamically inconsistent in several regards, most notably in its failure to include thermal noise in the description of the mechanical transitions by which motion occurs. This inconsistency has led subsequent workers to incorrect conclusions regarding the importance of mechanical transitions for determining the direction of motion, the efficiency of energy conversion, the ratio of forward to backward steps, and the applied force necessary to stop the motion of chemically driven molecular motors. In this chapter an extension of Huxley's model is described where the principle of microscopic reversibility provides a framework for developing a thermodynamically consistent description of a molecular machine. The results show clearly that mechanical strain and the so-called "power stroke" are irrelevant for determining the directionality and thermodynamic properties of any chemically driven molecular motor. Instead these properties are controlled entirely by the chemical specificity that describes how the relative rates of the ATP hydrolysis reaction depend, by allosteric interactions, on the mechanical state of the molecule. This mechanism has been termed an "information ratchet" in the literature. In contrast to the results for chemical driving, a power stroke can be a key component for the operation of an optically driven motor, the transitions of which do not obey microscopic reversibility. PMID:26122749

  15. Rival Visions: J.J. Rousseau and T.H. Huxley on the Nature (or Nurture) of Inequality and What It Means for Education

    ERIC Educational Resources Information Center

    Currie-Knight, Kevin

    2011-01-01

    Jean-Jacques Rousseau (1712-1778) and Thomas Huxley (1852-1895) had different, but substantial, effects on the history of education. Rousseau's educational theories supplied the intellectual foundation for pedagogical progressivism. Huxley's educational writings helped to enlarge the scope of the British curriculum to include such things as…

  16. A fuzzy logical model of letter identification.

    PubMed

    Oden, G C

    1979-05-01

    Stimuli were generated by factorially varying two sets of features that distinguish between two letter patterns. Subjects rated the degree to which each stimulus was an instance of one letter rather than the alternative. The obtained ratings were relatively continuous and systematic functions of the feature manipulations. The results were well accounted for by a model in which (a) each feature has an associated fuzzy predicate that is used to independently evaluate the degree to which it is true that the feature is present in the stimulus; (b) the featural truth values are integrated according to fuzzy logical expressions that correspond directly to propositional descriptions of each letter pattern; and (c) the resulting goodness of match to the stimulus for each letter is compared to that of the alternatives to determine the final identification. PMID:528944

  17. The time course of visual influences in letter recognition.

    PubMed

    Madec, Sylvain; Le Goff, Kévin; Riès, Stéphanie K; Legou, Thierry; Rousselet, Guillaume; Courrieu, Pierre; Alario, F-Xavier; Grainger, Jonathan; Rey, Arnaud

    2016-06-01

    This study builds on a specific characteristic of letters of the Roman alphabet-namely, that each letter name is associated with two visual formats, corresponding to their uppercase and lowercase versions. Participants had to read aloud the names of single letters, and event-related potentials (ERPs) for six pairs of visually dissimilar upper- and lowercase letters were recorded. Assuming that the end product of processing is the same for upper- and lowercase letters sharing the same vocal response, ERPs were compared backward, starting from the onset of articulatory responses, and the first significant divergence was observed 120 ms before response onset. Given that naming responses were produced at around 414 ms, on average, these results suggest that letter processing is influenced by visual information until 294 ms after stimulus onset. This therefore provides new empirical evidence regarding the time course and interactive nature of visual letter perception processes. PMID:26742753

  18. Solutions of the Hodgkin-Huxley equations modified for potassium accumulation in a periaxonal space.

    PubMed

    Adelman, W J; Fitzhugh, R

    1975-04-01

    Hodgkin and Huxley equations were modified to include the properties of an external diffusion barrier separated from the axolemma by a thin periaxonal space in which potassium ions accumulate as a function of membrane activity. Further modifications in the equations took into account new values for gK and new functions for alphan, betan, alphah, and betah derived from voltage clamp experiments on Loligo pealei giant axons. Equations were solved on a PDP-11 computer using the Gear predictor-corrector numerical method. In comparison with the original Hodgkin and Huxley equations, the modified equations for membrane potentials gave: 1) more accurate representations of the falling and undershoot phases of the membrane action potential, 2) more accurate representation of thresholds and latencies, 3) increases in the periaxonal space potassium ion concentration, Ks, of about 1 mM/impulse, 4) proper predictions of the time course and magnitude of either undershoot decline or periaxonal potassium ion accumulation during trains of membrane action potentials elicited by repetitivie short duration stimuli, and5) a somewhat more accurate representation of adaptation (finite train and nonrepetitive responses) during long duration constant current stimulation.

  19. The Business Letter.

    ERIC Educational Resources Information Center

    Nederland Independent School District, TX.

    GRADES OR AGES: Grades 9-12. SUBJECT MATTER: Business. ORGANIZATION AND PHYSICAL APPEARANCE: This guide, designed for direct student use, indicates the parts of a business letter, a placement guide, and steps for typing letters. Worksheets and illustrations indicate forms of block and indented styles; open, closed, and mixed punctuation; the…

  20. Letters from a Suicide

    ERIC Educational Resources Information Center

    Barnes, Donna Holland; Lawal-Solarin, Foluso Williams; Lester, David

    2007-01-01

    There has been no published study on personal letters written before an individual's suicidal death hitherto, although studies have been done using diaries. The purpose of this study was to search for trends in the use of particular linguistic categories in a series of personal letters written before an individual's suicidal death. A linguistic…

  1. Which Children Benefit from Letter Names in Learning Letter Sounds?

    ERIC Educational Resources Information Center

    Treiman, Rebecca; Pennington, Bruce F.; Shriberg, Lawrence D.; Boada, Richard

    2008-01-01

    Typical U.S. children use their knowledge of letters' names to help learn the letters' sounds. They perform better on letter sound tests with letters that have their sounds at the beginnings of their names, such as v, than with letters that have their sounds at the ends of their names, such as m, and letters that do not have their sounds in their…

  2. Writing effective consultation letters: 12 tips for teachers.

    PubMed

    Keely, Erin; Dojeiji, Suzan; Myers, Kathryn

    2002-11-01

    Written correspondence is the standard mode of communication between healthcare providers. Despite the importance of this skill and increased emphasis on ambulatory care, communication skills and professionalism in training programs, there has been very little written on the teaching and evaluation of consultation letter writing. Consultation letter writing is an essential skill that cannot be learned simply by reading others' letters and should be taught in a formal manner. This article describes the authors' experience in teaching the skill of writing effective consultation letters to residents and describes strategies for evaluating this skill.

  3. Writing effective consultation letters: 12 tips for teachers.

    PubMed

    Keely, Erin; Dojeiji, Suzan; Myers, Kathryn

    2002-11-01

    Written correspondence is the standard mode of communication between healthcare providers. Despite the importance of this skill and increased emphasis on ambulatory care, communication skills and professionalism in training programs, there has been very little written on the teaching and evaluation of consultation letter writing. Consultation letter writing is an essential skill that cannot be learned simply by reading others' letters and should be taught in a formal manner. This article describes the authors' experience in teaching the skill of writing effective consultation letters to residents and describes strategies for evaluating this skill. PMID:12623449

  4. Launch of Zoological Letters.

    PubMed

    Fukatsu, Takema; Kuratani, Shigeru

    2016-02-01

    A new open-access journal, Zoological Letters, was launched as a sister journal to Zoological Science, in January 2015. The new journal aims at publishing topical papers of high quality from a wide range of basic zoological research fields. This review highlights the notable reviews and research articles that have been published in the first year of Zoological Letters, providing an overview on the current achievements and future directions of the journal.

  5. Launch of Zoological Letters.

    PubMed

    Fukatsu, Takema; Kuratani, Shigeru

    2016-02-01

    A new open-access journal, Zoological Letters, was launched as a sister journal to Zoological Science, in January 2015. The new journal aims at publishing topical papers of high quality from a wide range of basic zoological research fields. This review highlights the notable reviews and research articles that have been published in the first year of Zoological Letters, providing an overview on the current achievements and future directions of the journal. PMID:26853862

  6. Predicting the past: ancient eclipses and Airy, Newcomb, and Huxley on the authority of science.

    PubMed

    Stanley, Matthew

    2012-06-01

    Greek historical accounts of ancient eclipses were an important, if peculiar, focus of scientific attention in the nineteenth century. Victorian-era astronomers tried to correct the classical histories using scientific methods, then used those histories as data with which to calibrate their lunar theories, then rejected the histories as having any relevance at all. The specific dating of these eclipses--apparently a simple exercise in celestial mechanics--became bound up with tensions between scientific and humanistic approaches to the past as well as with wider social debates over the power and authority of science in general. The major figures discussed here, including G. B. Airy, Simon Newcomb, and T. H. Huxley, argued that the critical question was whether science could speak authoritatively about the past. To them, the ability of science to talk about the past indicated its power to talk about the future; it was also the fulcrum of fierce boundary disputes among science, history, and religion.

  7. Predicting the past: ancient eclipses and Airy, Newcomb, and Huxley on the authority of science.

    PubMed

    Stanley, Matthew

    2012-06-01

    Greek historical accounts of ancient eclipses were an important, if peculiar, focus of scientific attention in the nineteenth century. Victorian-era astronomers tried to correct the classical histories using scientific methods, then used those histories as data with which to calibrate their lunar theories, then rejected the histories as having any relevance at all. The specific dating of these eclipses--apparently a simple exercise in celestial mechanics--became bound up with tensions between scientific and humanistic approaches to the past as well as with wider social debates over the power and authority of science in general. The major figures discussed here, including G. B. Airy, Simon Newcomb, and T. H. Huxley, argued that the critical question was whether science could speak authoritatively about the past. To them, the ability of science to talk about the past indicated its power to talk about the future; it was also the fulcrum of fierce boundary disputes among science, history, and religion. PMID:22908421

  8. Homoclinic bifurcation in a Hodgkin-Huxley model of thermally sensitive neurons

    SciTech Connect

    Feudel, Ulrike; Neiman, Alexander; Pei, Xing; Wojtenek, Winfried; Braun, Hans; Huber, Martin; Moss, Frank

    2000-03-01

    We study global bifurcations of the chaotic attractor in a modified Hodgkin-Huxley model of thermally sensitive neurons. The control parameter for this model is the temperature. The chaotic behavior is realized over a wide range of temperatures and is visualized using interspike intervals. We observe an abrupt increase of the interspike intervals in a certain temperature region. We identify this as a homoclinic bifurcation of a saddle-focus fixed point which is embedded in the chaotic attractors. The transition is accompanied by intermittency, which obeys a universal scaling law for the average length of trajectory segments exhibiting only short interspike intervals with the distance from the onset of intermittency. We also present experimental results of interspike interval measurements taken from the crayfish caudal photoreceptor, which qualitatively demonstrate the same bifurcation structure. (c) 2000 American Institute of Physics.

  9. Enhancing the Hodgkin-Huxley Equations: Simulations Based on the First Publication in the Biophysical Journal.

    PubMed

    Moore, John W

    2015-10-01

    The experiments in the Cole and Moore article in the first issue of the Biophysical Journal provided the first independent experimental confirmation of the Hodgkin-Huxley (HH) equations. A log-log plot of the K current versus time showed that raising the HH variable n to the sixth power provided the best fit to the data. Subsequent simulations using n(6) and setting the resting potential at the in vivo value simplifies the HH equations by eliminating the leakage term. Our article also reported that the K current in response to a depolarizing step to ENa was delayed if the step was preceded by a hyperpolarization. While the interpretation of this phenomenon in the article was flawed, subsequent simulations show that the effect completely arises from the original HH equations.

  10. Dynamic range in small-world networks of Hodgkin-Huxley neurons with chemical synapses

    NASA Astrophysics Data System (ADS)

    Batista, C. A. S.; Viana, R. L.; Lopes, S. R.; Batista, A. M.

    2014-09-01

    According to Stevens' law the relationship between stimulus and response is a power-law within an interval called the dynamic range. The dynamic range of sensory organs is found to be larger than that of a single neuron, suggesting that the network structure plays a key role in the behavior of both the scaling exponent and the dynamic range of neuron assemblies. In order to verify computationally the relationships between stimulus and response for spiking neurons, we investigate small-world networks of neurons described by the Hodgkin-Huxley equations connected by chemical synapses. We found that the dynamic range increases with the network size, suggesting that the enhancement of the dynamic range observed in sensory organs, with respect to single neurons, is an emergent property of complex network dynamics.

  11. Strange nonchaotic oscillations in the quasiperiodically forced Hodgkin-Huxley neuron

    NASA Astrophysics Data System (ADS)

    Lim, Woochang; Kim, Sang-Yoon

    2009-07-01

    We numerically study dynamical behaviors of the quasiperiodically forced Hodgkin-Huxley neuron and compare the dynamical responses with those for the case of periodic stimulus. In the periodically forced case, a transition from a periodic to a chaotic oscillation was found to occur via period doublings in previous numerical and experimental works. We investigate the effect of the quasiperiodic forcing on this period-doubling route to chaotic oscillation. In contrast to the case of periodic forcing, a new type of strange nonchaotic (SN) oscillating states (that are geometrically strange but have no positive Lyapunov exponents) is found to exist between the regular and chaotic oscillating states as intermediate ones. Their strange fractal geometry leads to aperiodic 'complex' spikings. Various dynamical routes to SN oscillations are identified, as in the quasiperiodically forced logistic map. These SN spikings are expected to be observed in experiments of the quasiperiodically forced squid giant axon.

  12. Enhancing the Hodgkin-Huxley Equations: Simulations Based on the First Publication in the Biophysical Journal

    PubMed Central

    Moore, John W.

    2015-01-01

    The experiments in the Cole and Moore article in the first issue of the Biophysical Journal provided the first independent experimental confirmation of the Hodgkin-Huxley (HH) equations. A log-log plot of the K current versus time showed that raising the HH variable n to the sixth power provided the best fit to the data. Subsequent simulations using n6 and setting the resting potential at the in vivo value simplifies the HH equations by eliminating the leakage term. Our article also reported that the K current in response to a depolarizing step to ENa was delayed if the step was preceded by a hyperpolarization. While the interpretation of this phenomenon in the article was flawed, subsequent simulations show that the effect completely arises from the original HH equations. PMID:26445431

  13. Students' Perceptions of Reference Letters

    ERIC Educational Resources Information Center

    Payne, Brian K.; Appel, Jonathan; Smith, Donald H.; Hoofnagle, Kara

    2006-01-01

    This study examines students' perceptions of reference letters. Students (n = 444) were asked to describe how they perceived reference letters. Four themes were uncovered. First, some students perceived reference letters as useful for employers. Second, some students perceived the letters as important for students seeking employment or admission…

  14. Temporal processing deficits in letter-by-letter reading.

    PubMed

    Ingles, Janet L; Eskes, Gail A

    2007-01-01

    Theories of the cognitive impairment underlying letter-by-letter reading vary widely, including prelexical and lexical level deficits. One prominent prelexical account proposes that the disorder results from difficulty in processing multiple letters simultaneously. We investigated whether this deficit extends to letters presented in rapid temporal succession. A letter-by-letter reader, G.M., was administered a rapid serial visual presentation task that has been used widely to study the temporal processing characteristics of the normal visual system. Comparisons were made to a control group of 6 brain-damaged individuals without reading deficits. Two target letters were embedded at varying temporal positions in a stream of rapidly presented single digits. After each stream, the identities of the two letters were reported. G.M. required an extended period of time after he had processed one letter before he was able to reliably identify a second letter, relative to the controls. In addition, G.M.'s report of the second letter was most impaired when it immediately followed the first letter, a pattern not seen in the controls, indicating that G.M. had difficulty processing the two items together. These data suggest that a letter-by-letter reading strategy may be adopted to help compensate for a deficit in the temporal processing of letters.

  15. Walking a Fine Line: Writing Negative Letters in an Insurance Company.

    ERIC Educational Resources Information Center

    Schryer, Catherine F.

    2000-01-01

    Examines the situated-language practices associated with the production of negative letters in an insurance company. Combines textual analyses of a set of negative letters together with writers' accounts of producing these letters to identify effective strategies for composing this correspondence. Identifies some strategies that characterize…

  16. Epistolary and Emotional Education: The Letters of an Irish Father to His Daughter, 1747-1752

    ERIC Educational Resources Information Center

    Ruberg, Willemijn

    2008-01-01

    The letters Bishop Edward Synge (1691-1762) wrote to his daughter Alicia (1733-1807) in 1747-1752 are discussed to show how correspondence from a father to a daughter could be used to teach a teenage girl how to spell and write letters. Moreover, these letters are an excellent source to show how emotional behaviour was taught. Instructions on…

  17. Human dynamics: Darwin and Einstein correspondence patterns.

    PubMed

    Oliveira, João Gama; Barabási, Albert-László

    2005-10-27

    In an era when letters were the main means of exchanging scientific ideas and results, Charles Darwin (1809-82) and Albert Einstein (1879-1955) were notably prolific correspondents. But did their patterns of communication differ from those associated with the instant-access e-mail of modern times? Here we show that, although the means have changed, the communication dynamics have not: Darwin's and Einstein's patterns of correspondence and today's electronic exchanges follow the same scaling laws. However, the response times of their surface-mail communication is described by a different scaling exponent from e-mail communication, providing evidence for a new class of phenomena in human dynamics.

  18. Human dynamics: Darwin and Einstein correspondence patterns

    NASA Astrophysics Data System (ADS)

    Oliveira, João Gama; Barabási, Albert-László

    2005-10-01

    In an era when letters were the main means of exchanging scientific ideas and results, Charles Darwin (1809-82) and Albert Einstein (1879-1955) were notably prolific correspondents. But did their patterns of communication differ from those associated with the instant-access e-mail of modern times? Here we show that, although the means have changed, the communication dynamics have not: Darwin's and Einstein's patterns of correspondence and today's electronic exchanges follow the same scaling laws. However, the response times of their surface-mail communication is described by a different scaling exponent from e-mail communication, providing evidence for a new class of phenomena in human dynamics.

  19. Priming of abstract letter representations may be universal: the case of Arabic.

    PubMed

    Carreiras, Manuel; Perea, Manuel; Abu Mallouh, Reem

    2012-08-01

    Recent research on the Roman alphabet has demonstrated that the magnitudes of masked repetition priming are equivalent for letter pairs that have similar visual features across cases (e.g., c-C) and for letter pairs with dissimilar features (e.g., g-G). Here, we examined whether priming of abstract letter representations occurs in an orthographic system, Arabic, in which the letters show an intricate number of contextual forms. Arabic does not have a lowercase/uppercase distinction, but the letters exhibit different forms that depend on their position (initial, medial, final, or isolated) and their connectivity. Importantly, some letters look quite different across positions (e.g., (symbol in text) and (symbol in text), which correspond to the letter 'ayn), whereas others look very similar (e.g. (symbol in text), and (symbol in text), which correspond to the letter fā'). We employed a masked priming same-different task, in which native speakers of Arabic decided whether a target letter was the same as or different from a reference letter presented in a different position (middle vs. isolated). The results showed masked repetition priming effects of the same magnitude for letter pairs with similar and with dissimilar visual features across letter positions. These data support the view that priming of abstract letter representations is a universal phenomenon. PMID:22569990

  20. Letters in this Issue

    NASA Astrophysics Data System (ADS)

    1998-01-01

    Reforming the General Chemistry Textbook individual letters by Edward T. Samulski; Stephen J. Hawkes; Stephen J. Fisher; J. Stephen Hartman; A. R. H. Cole; Stanley Pine, Ronald Archer, and Herbert Kaesz; Jimmy Reeves; Robert Hill; and Brock Spencer, C. Bradley Moore and Nedah Rose. Re: article by R. J. Gillespie The author replies

  1. Harvard Education Letter, 2000.

    ERIC Educational Resources Information Center

    Gordon, David T., Ed.

    2000-01-01

    This document is comprised of the six issues in volume 16 of the Harvard Education Letter, a bimonthly newsletter addressing current issues in elementary and secondary education. Articles in this volume include the following: (1) January-February--"Grade Inflation: What's Really behind All Those A's?" (Birk) and "Every Friday was Fight Day"…

  2. Inside the Letter

    ERIC Educational Resources Information Center

    Duke, Roger; Graham, Alan

    2007-01-01

    In this article, the authors describe how a Java applet can help to build learners' intuitions about basic ideas of algebra. "Matchbox Algebra" is a Java applet the authors have designed to enable learners to grasp a key idea in learning algebra: that the letter "x" may be thought of as representing an as-yet-unknown number. They describe the…

  3. Letter to Doxiadis

    ERIC Educational Resources Information Center

    Fuller, Buckminster

    1969-01-01

    The second half of a lengthy letter to Dr. Constantine Doxiadis (published in full in Main Currents in Modern Thought, XXV, March-April 1969) summarizes Buckminster Fuller's personal reflections on the impact of industrialization and on the effect of technological change in uniting mankind. (MF)

  4. Harvard Education Letter, 2001.

    ERIC Educational Resources Information Center

    Gordon, David, T., Ed.

    2001-01-01

    This document is comprised of the six issues in volume 17 of the Harvard Education Letter, a bimonthly newsletter addressing current issues in elementary and secondary education. Articles in this volume include the following: (1) January-February--"Charters and Districts: Three Stages in an Often Rocky Relationship" (Kelly) and "'We Don't Allow…

  5. Letters and American Literacy.

    ERIC Educational Resources Information Center

    Kevis, David E.

    The work itself should help a person who is going to teach reading and writing. Practical suggestions are offered in the final two chapters, while the opening three give intellectual perspectives. A theme binds the work of letting the consciousness of writing as a visual system be increased and of breaking the spell by which letter phonetics can…

  6. Five Long Letters.

    ERIC Educational Resources Information Center

    Bone, Eric

    1990-01-01

    Describes the life of former Louisiana governor Huey Long through five fictitious letters. Discusses Long's experiences as a state public service commissioner, governor, and senator. Attributes Long's assassination to his killer's personal motives. Concludes that Long's life showed how much personal power could be gained even in a democracy. (SG)

  7. Harvard Education Letter, 2002.

    ERIC Educational Resources Information Center

    Gordon, David T., Editor

    2002-01-01

    This document is comprised of the 6 issues in volume 18 of the Harvard Education Letter, a bimonthly newsletter addressing current issues in elementary and secondary education. Articles in this volume include the following: (1) January/February--"Curriculum Access in the Digital Age" (David T. Gordon) and "Using Charters To Improve Urban Schools"…

  8. The Fuzzy Scarlet Letter

    ERIC Educational Resources Information Center

    Pallas, Aaron M.

    2012-01-01

    Critics of the public release of teacher evaluation scores sometimes liken these ratings to the scarlet letter worn by Hester Prynne in Nathaniel Hawthorne's classic novel. The comparison is apt. But public school teachers who are subjected to public shaming because of their students' test scores can rarely expect the opportunities for redemption…

  9. A Nerve Model of Greatly Increased Energy-Efficiency and Encoding Flexibility over the Hodgkin-Huxley Model

    PubMed Central

    Fohlmeister, Jurgen F.

    2009-01-01

    A mammalian “RGC model” (retinal ganglion cells) is distinguished from the Hodgkin-Huxley model by the virtual absence of K-current during, and the virtual absence of Na-current after, the regenerative (rising) phase of the action potential. Both Na- and K-currents remain negligible throughout the interspike interval, whose control is therefore relinquished to stimulus currents. These properties yield a highly flexible and energy-efficient nerve impulse encoder. For the Hodgkin-Huxley model, in contrast, only 15 % of the Na-ions enter the axon regeneratively during the action potential (squid giant axon); a wasteful 85 % enter during the falling phase. Further, early activation of K-current causes the Na- and K-currents of the action potential to dominate over stimulus currents in controlling the sub-threshold membrane potential (interspike interval). This property makes the Hodgkin-Huxley model an intractable high frequency oscillator, which cannot be converted to flexible impulse encoding. The temperature difference between the squid giant axon (6.3° C) and RGCs (37° C) is bridged by a Q10 analysis, which suggests that an additional molecular gating mechanism of high Q10 – which is not present in the squid – is active in RGCs. PMID:19596283

  10. Vowel Cluster-Phoneme Correspondences in 20,000 English Words.

    ERIC Educational Resources Information Center

    Johnson, Dale D.

    The symbol-sound correspondence status of vowel-cluster (two or more adjacent vowel letters) spelling in American English was investigated. The source of the study was Venezky's 1963 revision of the Thorndike Frequency Count. A computer print-out of the 20,000 word corpus was analyzed to determine the letter-sound correspondence of vowel cluster…

  11. Null space in the Hodgkin-Huxley Equations. A critical test.

    PubMed Central

    Best, E N

    1979-01-01

    Voltage perturbation methods based upon topological concepts are used to elicit responses from the Hodgkin-Huxley (HH) nonlinear differential equations. These responses present a critical check upon the validity of the HH model for electrical activity across squid axon membrane. It is shown that when a constant current is applied such that a stable equilibrium and rhythmic firing are present, the following predictions are inherent in the HH system of equations: (a) Small instantaneous voltage perturbations to the axon given at points along its firing spike result in phase resetting curves (when new phase versus old phase is plotted) with an average slope of 1. (b) A larger voltage perturbation (from certain points along the firing spike) results in the permanent cessation of periodic firing, with membrane voltage rapidly approaching the equilibrium value. (c) A still larger perturbation yields phase resetting curves with an average slope equal to 0. These predictions, coupled with Tasaki's experimental demonstration that squid axons in excellent condition do give repetitive firing under constant current, provide a critical test of the validity of the HH model. Images FIGURE 3 PMID:262379

  12. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model.

    PubMed

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders.

  13. Chimera states in a Hodgkin-Huxley model of thermally sensitive neurons.

    PubMed

    Glaze, Tera A; Lewis, Scott; Bahar, Sonya

    2016-08-01

    Chimera states occur when identically coupled groups of nonlinear oscillators exhibit radically different dynamics, with one group exhibiting synchronized oscillations and the other desynchronized behavior. This dynamical phenomenon has recently been studied in computational models and demonstrated experimentally in mechanical, optical, and chemical systems. The theoretical basis of these states is currently under active investigation. Chimera behavior is of particular relevance in the context of neural synchronization, given the phenomenon of unihemispheric sleep and the recent observation of asymmetric sleep in human patients with sleep apnea. The similarity of neural chimera states to neural "bump" states, which have been suggested as a model for working memory and visual orientation tuning in the cortex, adds to their interest as objects of study. Chimera states have been demonstrated in the FitzHugh-Nagumo model of excitable cells and in the Hindmarsh-Rose neural model. Here, we demonstrate chimera states and chimera-like behaviors in a Hodgkin-Huxley-type model of thermally sensitive neurons both in a system with Abrams-Strogatz (mean field) coupling and in a system with Kuramoto (distance-dependent) coupling. We map the regions of parameter space for which chimera behavior occurs in each of the two coupling schemes.

  14. Chimera states in a Hodgkin-Huxley model of thermally sensitive neurons

    NASA Astrophysics Data System (ADS)

    Glaze, Tera A.; Lewis, Scott; Bahar, Sonya

    2016-08-01

    Chimera states occur when identically coupled groups of nonlinear oscillators exhibit radically different dynamics, with one group exhibiting synchronized oscillations and the other desynchronized behavior. This dynamical phenomenon has recently been studied in computational models and demonstrated experimentally in mechanical, optical, and chemical systems. The theoretical basis of these states is currently under active investigation. Chimera behavior is of particular relevance in the context of neural synchronization, given the phenomenon of unihemispheric sleep and the recent observation of asymmetric sleep in human patients with sleep apnea. The similarity of neural chimera states to neural "bump" states, which have been suggested as a model for working memory and visual orientation tuning in the cortex, adds to their interest as objects of study. Chimera states have been demonstrated in the FitzHugh-Nagumo model of excitable cells and in the Hindmarsh-Rose neural model. Here, we demonstrate chimera states and chimera-like behaviors in a Hodgkin-Huxley-type model of thermally sensitive neurons both in a system with Abrams-Strogatz (mean field) coupling and in a system with Kuramoto (distance-dependent) coupling. We map the regions of parameter space for which chimera behavior occurs in each of the two coupling schemes.

  15. Giant squid-hidden canard: the 3D geometry of the Hodgkin-Huxley model.

    PubMed

    Rubin, Jonathan; Wechselberger, Martin

    2007-07-01

    This work is motivated by the observation of remarkably slow firing in the uncoupled Hodgkin-Huxley model, depending on parameters tau( h ), tau( n ) that scale the rates of change of the gating variables. After reducing the model to an appropriate nondimensionalized form featuring one fast and two slow variables, we use geometric singular perturbation theory to analyze the model's dynamics under systematic variation of the parameters tau( h ), tau( n ), and applied current I. As expected, we find that for fixed (tau( h ), tau( n )), the model undergoes a transition from excitable, with a stable resting equilibrium state, to oscillatory, featuring classical relaxation oscillations, as I increases. Interestingly, mixed-mode oscillations (MMO's), featuring slow action potential generation, arise for an intermediate range of I values, if tau( h ) or tau( n ) is sufficiently large. Our analysis explains in detail the geometric mechanisms underlying these results, which depend crucially on the presence of two slow variables, and allows for the quantitative estimation of transitional parameter values, in the singular limit. In particular, we show that the subthreshold oscillations in the observed MMO patterns arise through a generalized canard phenomenon. Finally, we discuss the relation of results obtained in the singular limit to the behavior observed away from, but near, this limit.

  16. FPGA implementation of a biological neural network based on the Hodgkin-Huxley neuron model.

    PubMed

    Yaghini Bonabi, Safa; Asgharian, Hassan; Safari, Saeed; Nili Ahmadabadi, Majid

    2014-01-01

    A set of techniques for efficient implementation of Hodgkin-Huxley-based (H-H) model of a neural network on FPGA (Field Programmable Gate Array) is presented. The central implementation challenge is H-H model complexity that puts limits on the network size and on the execution speed. However, basics of the original model cannot be compromised when effect of synaptic specifications on the network behavior is the subject of study. To solve the problem, we used computational techniques such as CORDIC (Coordinate Rotation Digital Computer) algorithm and step-by-step integration in the implementation of arithmetic circuits. In addition, we employed different techniques such as sharing resources to preserve the details of model as well as increasing the network size in addition to keeping the network execution speed close to real time while having high precision. Implementation of a two mini-columns network with 120/30 excitatory/inhibitory neurons is provided to investigate the characteristic of our method in practice. The implementation techniques provide an opportunity to construct large FPGA-based network models to investigate the effect of different neurophysiological mechanisms, like voltage-gated channels and synaptic activities, on the behavior of a neural network in an appropriate execution time. Additional to inherent properties of FPGA, like parallelism and re-configurability, our approach makes the FPGA-based system a proper candidate for study on neural control of cognitive robots and systems as well.

  17. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model.

    PubMed

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders. PMID:27148032

  18. Global Bifurcation Structure and Parameter Dependence of the Hodgkin-Huxley Equations

    NASA Astrophysics Data System (ADS)

    Pan, Zhenxing; Doi, Shinji

    The Hodgkin-Huxley (HH) equations of a squid giant axon are the most important mathematical model in electrophysiology and biology, and are also important in the development of various biologically inspired intelligent devices such as artificial neuron device and neural networks. The HH equations, however, include various constants or parameters whose values were determined based on physiological experiments, and thus the values possess inherent ambiguities. Also, the ‘constants’ are not really constant but change temporally. Thus, in this paper, we study the effects of the change of the constants or parameters on the dynamics of the HH equations and consider the parameter dependence and sensitivity of the equations; we study the bifurcation structure of the HH equations by changing their various parameters. In particular, we take the voltage-dependency of the dynamics of so-called gating variables as typical bifurcation parameters and show that the HH dynamics is very sensitive to the steady-state functions but not sensitive to the time ‘constants’ of gating variables.

  19. Theoretical Analysis of Transcranial Magneto-Acoustical Stimulation with Hodgkin-Huxley Neuron Model

    PubMed Central

    Yuan, Yi; Chen, Yudong; Li, Xiaoli

    2016-01-01

    Transcranial magneto-acoustical stimulation (TMAS) is a novel stimulation technology in which an ultrasonic wave within a magnetostatic field generates an electric current in an area of interest in the brain to modulate neuronal activities. As a key part of the neural network, neurons transmit information in the nervous system. However, the effect of TMAS on the neuronal firing pattern remains unknown. To address this problem, we investigated the stimulatory mechanism of TMAS on neurons, by using a Hodgkin-Huxley neuron model. The simulation results indicated that the magnetostatic field intensity and ultrasonic power affect the amplitude and interspike interval of neuronal action potential under a continuous wave ultrasound. The simulation results also showed that the ultrasonic power, duty cycle and repetition frequency can alter the firing pattern of neural action potential under pulsed wave ultrasound. This study may help to reveal and explain the biological mechanism of TMAS and to provide a theoretical basis for TMAS in the treatment or rehabilitation of neuropsychiatric disorders. PMID:27148032

  20. Chimera states in a Hodgkin-Huxley model of thermally sensitive neurons.

    PubMed

    Glaze, Tera A; Lewis, Scott; Bahar, Sonya

    2016-08-01

    Chimera states occur when identically coupled groups of nonlinear oscillators exhibit radically different dynamics, with one group exhibiting synchronized oscillations and the other desynchronized behavior. This dynamical phenomenon has recently been studied in computational models and demonstrated experimentally in mechanical, optical, and chemical systems. The theoretical basis of these states is currently under active investigation. Chimera behavior is of particular relevance in the context of neural synchronization, given the phenomenon of unihemispheric sleep and the recent observation of asymmetric sleep in human patients with sleep apnea. The similarity of neural chimera states to neural "bump" states, which have been suggested as a model for working memory and visual orientation tuning in the cortex, adds to their interest as objects of study. Chimera states have been demonstrated in the FitzHugh-Nagumo model of excitable cells and in the Hindmarsh-Rose neural model. Here, we demonstrate chimera states and chimera-like behaviors in a Hodgkin-Huxley-type model of thermally sensitive neurons both in a system with Abrams-Strogatz (mean field) coupling and in a system with Kuramoto (distance-dependent) coupling. We map the regions of parameter space for which chimera behavior occurs in each of the two coupling schemes. PMID:27586615

  1. On the noise-enhancing ability of stochastic Hodgkin-Huxley neuron systems.

    PubMed

    Chen, Bor-Sen; Li, Cheng-Wei

    2010-07-01

    Recently noise has been shown to be useful in enhancing neuron sensitivity by stochastic resonance. In this study, in order to measure the noise-enhancing factor (NEF), a nonlinear stochastic model is introduced for the Hodgkin-Huxley (HH) neuron system with synaptic noise input stimulation and channel noises in the sodium and potassium channels. The enhancing factor of the HH neuron system is measured from the point of view of the noise-exploiting level of nonlinear stochastic H(infinity) signal processing. Since the nonlinear stochastic-enhancing measure problem of HH neuron systems requires a solution for the difficulty presented by the Hamilton Jacobi inequality (HJI), a fuzzy interpolation of locally linearized systems is employed to simplify the nonlinear noise-enhancing problems by solving only a set of linear matrix inequalities. The NEF of the HH neuron system is found to be related to the locations of eigenvalues of linearized HH neuron systems and can be estimated through the H(infinity) signal processing method. Based on a stochastic fuzzy linearized HH neuron system, we found that channel noises are enhanced by the active eigenvalues of ionic channels while synaptic noises are attenuated by the passive eigenvalues of synaptic process. PMID:20235824

  2. Modelling spatiotemporal olfactory data in two steps: from binary to Hodgkin-Huxley neurones.

    PubMed

    Quenet, Brigitte; Dubois, Rémi; Sirapian, Sevan; Dreyfus, Gérard; Horn, David

    2002-01-01

    Network models of synchronously updated McCulloch-Pitts neurones exhibit complex spatiotemporal patterns that are similar to activities of biological neurones in phase with a periodic local field potential, such as those observed experimentally by Wehr and Laurent (1996, Nature 384, 162-166) in the locust olfactory pathway. Modelling biological neural nets with networks of simple formal units makes the dynamics of the model analytically tractable. It is thus possible to determine the constraints that must be satisfied by its connection matrix in order to make its neurones exhibit a given sequence of activity (see, for instance, Quenet et al., 2001, Neurocomputing 38-40, 831-836). In the present paper, we address the following question: how can one construct a formal network of Hodgkin-Huxley (HH) type neurones that reproduces experimentally observed neuronal codes? A two-step strategy is suggested in the present paper: first, a simple network of binary units is designed, whose activity reproduces the binary experimental codes; second, this model is used as a guide to design a network of more realistic formal HH neurones. We show that such a strategy is indeed fruitful: it allowed us to design a model that reproduces the Wehr-Laurent olfactory codes, and to investigate the robustness of these codes to synaptic noise.

  3. Quantification of degeneracy in Hodgkin-Huxley neurons on Newman-Watts small world network.

    PubMed

    Man, Menghua; Zhang, Ya; Ma, Guilei; Friston, Karl; Liu, Shanghe

    2016-08-01

    Degeneracy is a fundamental source of biological robustness, complexity and evolvability in many biological systems. However, degeneracy is often confused with redundancy. Furthermore, the quantification of degeneracy has not been addressed for realistic neuronal networks. The objective of this paper is to characterize degeneracy in neuronal network models via quantitative mathematic measures. Firstly, we establish Hodgkin-Huxley neuronal networks with Newman-Watts small world network architectures. Secondly, in order to calculate the degeneracy, redundancy and complexity in the ensuing networks, we use information entropy to quantify the information a neuronal response carries about the stimulus - and mutual information to measure the contribution of each subset of the neuronal network. Finally, we analyze the interdependency of degeneracy, redundancy and complexity - and how these three measures depend upon network architectures. Our results suggest that degeneracy can be applied to any neuronal network as a formal measure, and degeneracy is distinct from redundancy. Qualitatively degeneracy and complexity are more highly correlated over different network architectures, in comparison to redundancy. Quantitatively, the relationship between both degeneracy and redundancy depends on network coupling strength: both degeneracy and redundancy increase with complexity for small coupling strengths; however, as coupling strength increases, redundancy decreases with complexity (in contrast to degeneracy, which is relatively invariant). These results suggest that the degeneracy is a general topologic characteristic of neuronal networks, which could be applied quantitatively in neuroscience and connectomics.

  4. Quantification of degeneracy in Hodgkin-Huxley neurons on Newman-Watts small world network.

    PubMed

    Man, Menghua; Zhang, Ya; Ma, Guilei; Friston, Karl; Liu, Shanghe

    2016-08-01

    Degeneracy is a fundamental source of biological robustness, complexity and evolvability in many biological systems. However, degeneracy is often confused with redundancy. Furthermore, the quantification of degeneracy has not been addressed for realistic neuronal networks. The objective of this paper is to characterize degeneracy in neuronal network models via quantitative mathematic measures. Firstly, we establish Hodgkin-Huxley neuronal networks with Newman-Watts small world network architectures. Secondly, in order to calculate the degeneracy, redundancy and complexity in the ensuing networks, we use information entropy to quantify the information a neuronal response carries about the stimulus - and mutual information to measure the contribution of each subset of the neuronal network. Finally, we analyze the interdependency of degeneracy, redundancy and complexity - and how these three measures depend upon network architectures. Our results suggest that degeneracy can be applied to any neuronal network as a formal measure, and degeneracy is distinct from redundancy. Qualitatively degeneracy and complexity are more highly correlated over different network architectures, in comparison to redundancy. Quantitatively, the relationship between both degeneracy and redundancy depends on network coupling strength: both degeneracy and redundancy increase with complexity for small coupling strengths; however, as coupling strength increases, redundancy decreases with complexity (in contrast to degeneracy, which is relatively invariant). These results suggest that the degeneracy is a general topologic characteristic of neuronal networks, which could be applied quantitatively in neuroscience and connectomics. PMID:27155043

  5. Overcoming the effect of letter confusability in letter-by-letter reading: a rehabilitation study.

    PubMed

    Harris, Lara; Olson, Andrew; Humphreys, Glyn

    2013-01-01

    Patients who read in a letter-by-letter manner can demonstrate effects of lexical variables when reading words comprised of low confusability letters, suggesting the capacity to process low-confusability words in parallel across the letters (Fiset, Arguin, & McCabe, 2006). Here a series of experiments is presented investigating letter confusability effects in MAH, a patient with expressive and receptive aphasia who shows reduced reading accuracy with longer words, and DM, a relatively "pure" alexic patient. Two rehabilitation studies were employed: (i) a word-level therapy and (ii) a letter-level therapy designed to improve discrimination of individual letters. The word-level treatment produced generalised improvement to low-confusability words only, but the serial processing treatment produced improvement on both high and low confusability words. The results add support to the hypothesis that letter confusability plays a key role in letter-by-letter reading, and suggest that a rehabilitation method aimed at reducing ambiguities in letter identification may be particularly effective for treating letter-by-letter reading.

  6. New Insights about Letter Learning

    ERIC Educational Resources Information Center

    Dougherty Stahl, Katherine A.

    2015-01-01

    The acquisition of alphabetic knowledge (letter names, letter sounds, and letter forms) is an important predictor of later literacy achievement. This article describes research findings that provide new insights about how children learn the alphabetic principle and the implications for effective and efficient instruction of the alphabet. Teachers…

  7. Letters to a Young Writer.

    ERIC Educational Resources Information Center

    Wright, C. D.; Schulman, Grace

    2001-01-01

    Presents two letters to a young writer, modeled on the influential "Letters to a Young Poet" by Rainer Maria Rilke. Notes the first letter situates itself when a young writer first turns toward poetry; and the second addresses the relationship between mentorship and the imagination, questioning the right of any writer to presume to guide the…

  8. Task switching and response correspondence in the psychological refractory period paradigm

    NASA Technical Reports Server (NTRS)

    Lien, Mei-Ching; Schweickert, Richard; Proctor, Robert W.

    2003-01-01

    Three experiments examined the effects of task switching and response correspondence in a psychological refractory period paradigm. A letter task (vowel-consonant) and a digit task (odd-even) were combined to form 4 possible dual-task pairs in each trial: letter-letter, letter-digit, digit-digit, and digit-letter. Foreknowledge of task transition (repeat or switch) and task identity (letter or digit) was varied across experiments: no foreknowledge in Experiment 1, partial foreknowledge (task transition only) in Experiment 2, and full foreknowledge in Experiment 3. For all experiments, the switch cost for Task 2 was additive with stimulus onset asynchrony, and the response-correspondence effect for Task 2 was numerically smaller in the switch condition than in the repeat condition. These outcomes suggest that reconfiguration for Task 2 takes place after the central processing of Task 1 and that the crosstalk correspondence effect is due to response activation by way of stimulus-response associations.

  9. Letters to the Editor

    NASA Astrophysics Data System (ADS)

    2000-11-01

    All the Letters to the Editor in this issue are in the same PostScript or PDF file. Contents The equivalence of mass and energy Peter Stansbury Head of Physics, Christ Church Grammar School, Claremont, Western Australia 6010 Comment on `A simple experiment to study parabolic surfaces' N Gauthier Department of Physics, The Royal Military College of Canada, Kingston, Ontario K7K 7B4, Canada

  10. Letters to the Editor

    NASA Astrophysics Data System (ADS)

    1997-03-01

    All the Letters to the Editor in this issue are in the same PostScript or PDF file. Contents Criticisms of hands-on pseudoscience David J Fisher 27 Elderberry Road, Cardiff CF5 3RG, UK Measuring varying fields Don Koks Adelaide University, Australia Relativity at A-level: a comment David Sang 3 Ellasdale Road, Bognor Regis, PO21 2SG, UK

  11. A comparison of letter and digit processing in letter-by-letter reading.

    PubMed

    Ingles, Janet L; Eskes, Gail A

    2008-01-01

    The extent to which letter-by-letter reading results from a specific orthographic deficit, as compared with a nonspecific disturbance in basic visuoperceptual mechanisms, is unclear. The current study directly compared processing of letters and digits in a letter-by-letter reader, G.M., using a rapid serial visual presentation (RSVP) task and a speeded matching task. Comparisons were made to a group of six brain-damaged individuals without reading deficits. In the RSVP task, G.M. had increased difficulty reporting the target identities when they were letters, as compared with digits. Although this general pattern was also evident in the control group, the magnitude of the letter-digit accuracy difference was greater in G.M. Similarly, in the matching task, G.M. was slower to match letters than digits, relative to the control group, although his response times to both item types were increased. These data suggest that letter-by-letter reading, at least in this case, results from a visuoperceptual encoding deficit that particularly affects letters, but also extends to processing of digits to a lesser extent. Results are consistent with the notion that a left occipitotemporal area is specialized for letter processing with greater bilaterality in the visual processing of digits.

  12. Demonstrating the Correspondence Bias

    ERIC Educational Resources Information Center

    Howell, Jennifer L.; Shepperd, James A.

    2011-01-01

    Among the best-known and most robust biases in person perception is the correspondence bias--the tendency for people to make dispositional, rather than situational, attributions for an actor's behavior. The correspondence bias appears in virtually every social psychology textbook and in many introductory psychology textbooks, yet the authors'…

  13. Young Children's Letter-Sound Knowledge.

    ERIC Educational Resources Information Center

    Dodd, Barbara; Carr, Alex

    2003-01-01

    This study with 83 normally developing children (ages 4-6) compared three essential skills in early literacy, letter-sound recognition, letter-sound recall, and letter reproduction. Children performed better in letter-sound recognition than in letter-sound recall and letter reproduction. There were no performance differences due to sex or age.…

  14. Recovery in a letter-by-letter reader: more efficiency at the expense of normal reading strategy.

    PubMed

    Ablinger, Irene; Huber, Walter; Schattka, Kerstin I; Radach, Ralph

    2013-01-01

    Although changes in reading performance of recovering letter-by-letter readers have been described in some detail, no prior research has provided an in-depth analysis of the underlying adaptive word processing strategies. Our work examined the reading performance of a letter-by-letter reader, FH, over a period of 15 months, using eye movement methodology to delineate the recovery process at two different time points (T1, T2). A central question is whether recovery is characterized either by moving back towards normal word processing or by refinement and possibly automatization of an existing pathological strategy that was developed in response to the impairment. More specifically, we hypothesized that letter-by-letter reading may be executed with at least four different strategies and our work sought to distinguish between these alternatives. During recovery significant improvements in reading performance were achieved. A shift of fixation positions from the far left to the extreme right of target words was combined with many small and very few longer regressive saccades. Apparently, 'letter-by-letter reading' took the form of local clustering, most likely corresponding to the formation of sublexical units of analysis. This pattern was more pronounced at T2, suggesting that improvements in reading efficiency may come at the expense of making it harder to eventually return to normal reading.

  15. Power-Law Dynamics of Membrane Conductances Increase Spiking Diversity in a Hodgkin-Huxley Model

    PubMed Central

    Teka, Wondimu; Stockton, David; Santamaria, Fidel

    2016-01-01

    We studied the effects of non-Markovian power-law voltage dependent conductances on the generation of action potentials and spiking patterns in a Hodgkin-Huxley model. To implement slow-adapting power-law dynamics of the gating variables of the potassium, n, and sodium, m and h, conductances we used fractional derivatives of order η≤1. The fractional derivatives were used to solve the kinetic equations of each gate. We systematically classified the properties of each gate as a function of η. We then tested if the full model could generate action potentials with the different power-law behaving gates. Finally, we studied the patterns of action potential that emerged in each case. Our results show the model produces a wide range of action potential shapes and spiking patterns in response to constant current stimulation as a function of η. In comparison with the classical model, the action potential shapes for power-law behaving potassium conductance (n gate) showed a longer peak and shallow hyperpolarization; for power-law activation of the sodium conductance (m gate), the action potentials had a sharp rise time; and for power-law inactivation of the sodium conductance (h gate) the spikes had wider peak that for low values of η replicated pituitary- and cardiac-type action potentials. With all physiological parameters fixed a wide range of spiking patterns emerged as a function of the value of the constant input current and η, such as square wave bursting, mixed mode oscillations, and pseudo-plateau potentials. Our analyses show that the intrinsic memory trace of the fractional derivative provides a negative feedback mechanism between the voltage trace and the activity of the power-law behaving gate variable. As a consequence, power-law behaving conductances result in an increase in the number of spiking patterns a neuron can generate and, we propose, expand the computational capacity of the neuron. PMID:26937967

  16. Power-Law Dynamics of Membrane Conductances Increase Spiking Diversity in a Hodgkin-Huxley Model.

    PubMed

    Teka, Wondimu; Stockton, David; Santamaria, Fidel

    2016-03-01

    We studied the effects of non-Markovian power-law voltage dependent conductances on the generation of action potentials and spiking patterns in a Hodgkin-Huxley model. To implement slow-adapting power-law dynamics of the gating variables of the potassium, n, and sodium, m and h, conductances we used fractional derivatives of order η≤1. The fractional derivatives were used to solve the kinetic equations of each gate. We systematically classified the properties of each gate as a function of η. We then tested if the full model could generate action potentials with the different power-law behaving gates. Finally, we studied the patterns of action potential that emerged in each case. Our results show the model produces a wide range of action potential shapes and spiking patterns in response to constant current stimulation as a function of η. In comparison with the classical model, the action potential shapes for power-law behaving potassium conductance (n gate) showed a longer peak and shallow hyperpolarization; for power-law activation of the sodium conductance (m gate), the action potentials had a sharp rise time; and for power-law inactivation of the sodium conductance (h gate) the spikes had wider peak that for low values of η replicated pituitary- and cardiac-type action potentials. With all physiological parameters fixed a wide range of spiking patterns emerged as a function of the value of the constant input current and η, such as square wave bursting, mixed mode oscillations, and pseudo-plateau potentials. Our analyses show that the intrinsic memory trace of the fractional derivative provides a negative feedback mechanism between the voltage trace and the activity of the power-law behaving gate variable. As a consequence, power-law behaving conductances result in an increase in the number of spiking patterns a neuron can generate and, we propose, expand the computational capacity of the neuron.

  17. Coarse-grained event tree analysis for quantifying Hodgkin-Huxley neuronal network dynamics.

    PubMed

    Sun, Yi; Rangan, Aaditya V; Zhou, Douglas; Cai, David

    2012-02-01

    We present an event tree analysis of studying the dynamics of the Hodgkin-Huxley (HH) neuronal networks. Our study relies on a coarse-grained projection to event trees and to the event chains that comprise these trees by using a statistical collection of spatial-temporal sequences of relevant physiological observables (such as sequences of spiking multiple neurons). This projection can retain information about network dynamics that covers multiple features, swiftly and robustly. We demonstrate that for even small differences in inputs, some dynamical regimes of HH networks contain sufficiently higher order statistics as reflected in event chains within the event tree analysis. Therefore, this analysis is effective in discriminating small differences in inputs. Moreover, we use event trees to analyze the results computed from an efficient library-based numerical method proposed in our previous work, where a pre-computed high resolution data library of typical neuronal trajectories during the interval of an action potential (spike) allows us to avoid resolving the spikes in detail. In this way, we can evolve the HH networks using time steps one order of magnitude larger than the typical time steps used for resolving the trajectories without the library, while achieving comparable statistical accuracy in terms of average firing rate and power spectra of voltage traces. Our numerical simulation results show that the library method is efficient in the sense that the results generated by using this numerical method with much larger time steps contain sufficiently high order statistical structure of firing events that are similar to the ones obtained using a regular HH solver. We use our event tree analysis to demonstrate these statistical similarities.

  18. Stochastic differential equation models for ion channel noise in Hodgkin-Huxley neurons.

    PubMed

    Goldwyn, Joshua H; Imennov, Nikita S; Famulare, Michael; Shea-Brown, Eric

    2011-04-01

    The random transitions of ion channels between conducting and nonconducting states generate a source of internal fluctuations in a neuron, known as channel noise. The standard method for modeling the states of ion channels nonlinearly couples continuous-time Markov chains to a differential equation for voltage. Beginning with the work of R. F. Fox and Y.-N. Lu [Phys. Rev. E 49, 3421 (1994)], there have been attempts to generate simpler models that use stochastic differential equation (SDEs) to approximate the stochastic spiking activity produced by Markov chain models. Recent numerical investigations, however, have raised doubts that SDE models can capture the stochastic dynamics of Markov chain models.We analyze three SDE models that have been proposed as approximations to the Markov chain model: one that describes the states of the ion channels and two that describe the states of the ion channel subunits. We show that the former channel-based approach can capture the distribution of channel noise and its effects on spiking in a Hodgkin-Huxley neuron model to a degree not previously demonstrated, but the latter two subunit-based approaches cannot. Our analysis provides intuitive and mathematical explanations for why this is the case. The temporal correlation in the channel noise is determined by the combinatorics of bundling subunits into channels, but the subunit-based approaches do not correctly account for this structure. Our study confirms and elucidates the findings of previous numerical investigations of subunit-based SDE models. Moreover, it presents evidence that Markov chain models of the nonlinear, stochastic dynamics of neural membranes can be accurately approximated by SDEs. This finding opens a door to future modeling work using SDE techniques to further illuminate the effects of ion channel fluctuations on electrically active cells. PMID:21599202

  19. Comparison of the validity of Hill and Huxley muscle-tendon complex models using experimental data obtained from rat m. soleus in situ.

    PubMed

    Lemaire, Koen K; Baan, Guus C; Jaspers, Richard T; van Soest, A J Knoek

    2016-04-01

    The relationship between mechanical and metabolic behaviour in the widely used Hill muscle-tendon complex (MTC) model is not straightforward, whereas this is an integral part of the Huxley model. In this study, we assessed to what extent Huxley- and Hill-type MTC models yield adequate predictions of mechanical muscle behaviour during stretch-shortening cycles (SSCs). In fully anaesthetized male Wistar rats (N=3), m. soleus was dissected completely free, except for the insertion. Cuff electrodes were placed over the n. ischiadicus. The distal end of the tendon was connected to a servo motor, via a force transducer. The setup allowed for full control over muscle stimulation and length, while force was measured. Quick-release and isovelocity contractions (part 1), and SSCs (part 2) were imposed. Simulations of part 2 were made with both a Hill and a Huxley MTC model, using parameter values determined from part 1. Modifications to the classic two-state Huxley model were made to incorporate series elasticity, activation dynamics, and active and passive force-length relationships. Results were similar for all rats. Fitting of the free parameters to the data of part 1 was near perfect (R(2)>0.97). During SSCs, predicted peak force and force during relaxation deviated from the experimental data for both models. Overall, both models yielded similarly adequate predictions of the experimental data. We conclude that Huxley and Hill MTC models are equally valid with respect to mechanical behaviour.

  20. Letters to the Editor

    NASA Astrophysics Data System (ADS)

    1997-01-01

    All the Letters to the Editor in this issue are in the same PostScript or PDF file. Contents Software teaching of modular physics: SToMP Stephen Hearn Head of Science, Charterhouse, Godalming, Surrey GU7 2DX Bridging the gap or avoiding a chasm? R W West York Strengths and weaknesses of science John Bausor Christians in Science Education, Edgware, London HA8 6RR Addressing the issues Philip Britton Head of Physics, Leeds Grammar School Modern syllabuses and old textbooks: a useful synthesis Richard Barrass St Mary's College, Doncaster DN1 2ES

  1. Letters to the Editor

    NASA Astrophysics Data System (ADS)

    1998-03-01

    All the Letters to the Editor in this issue are in the same PostScript or PDF file. Contents Comment on `Magnetic and electric field strengths of high voltage power lines and household appliances' José Luis Giordano Dept. de Ciencia y Tecnología de Materiales y Fluidos, CPSI, Universidad de Zaragoza, Spain Twins paradox S R Carson Norton College, Malton, North Yorkshire, UK On alternative ways of finding the ratio of specific heats of gases Tomas Ficker Physics Department, Technical University of Brno, Czech Republic

  2. The letter height superiority illusion.

    PubMed

    New, Boris; Doré-Mazars, Karine; Cavézian, Céline; Pallier, Christophe; Barra, Julien

    2016-02-01

    Letters are identified better when they are embedded within words rather than within pseudowords, a phenomenon known as the word superiority effect (Reicher in Journal of Experimental Psychology, 81, 275-280, 1969). This effect is, inter alia, accounted for by the interactive-activation model (McClelland & Rumelhart in Psychological Review, 88, 375-407, 1981) through feedback from word to letter nodes. In this study, we investigated whether overactivation of features could lead to perceptual bias, wherein letters would be perceived as being taller than pseudoletters, or words would be perceived as being taller than pseudowords. In two experiments, we investigated the effects of letter and lexical status on the perception of size. Participants who had to compare the heights of letters and pseudoletters, or of words and pseudowords, indeed perceived the former stimuli as being taller than the latter. Possible alternative interpretations of this height superiority effect for letters and words are discussed. PMID:26370216

  3. The Visuo-Haptic and Haptic Exploration of Letters Increases the Kindergarten-Children's Understanding of the Alphabetic Principle

    ERIC Educational Resources Information Center

    Bara, Florence; Gentaz, Edouard; Cole, Pascale; Sprenger-Charolles, Liliane

    2004-01-01

    This study examined the effect of incorporating a visuo-haptic and haptic (tactual-kinaesthetic) exploration of letters in a training designed to develop phonemic awareness, knowledge of letters and letter/sound correspondences, on 5-year-old children's understanding and use of the alphabetic principle. Three interventions, which differed in the…

  4. Michael Maier--nine newly discovered letters.

    PubMed

    Lenke, Nils; Roudet, Nicolas; Tilton, Hereward

    2014-02-01

    The authors provide a transcription, translation, and evaluation of nine newly discovered letters from the alchemist Michael Maier (1568-1622) to Gebhardt Johann von Alvensleben (1576-1631), a noble landholder in the vicinity of Magdeburg. Stemming from the final year of his life, this correspondence casts new light on Maier's biography, detailing his efforts to secure patronage amid the financial crisis of the early Thirty Years' War. While his ill-fated quest to perfect potable gold continued to form the central focus of his patronage suits, Maier also offered his services in several arts that he had condemned in his printed works, namely astrology and "supernatural" magic. Remarks concerning his previously unknown acquaintance with Heinrich Khunrath call for a re-evaluation of Maier's negotiation of the discursive boundaries between Lutheran orthodoxy and Paracelsianism. The letters also reveal Maier's substantial contribution to a work previously ascribed solely to the English alchemist Francis Anthony. PMID:25241502

  5. Michael Maier--nine newly discovered letters.

    PubMed

    Lenke, Nils; Roudet, Nicolas; Tilton, Hereward

    2014-02-01

    The authors provide a transcription, translation, and evaluation of nine newly discovered letters from the alchemist Michael Maier (1568-1622) to Gebhardt Johann von Alvensleben (1576-1631), a noble landholder in the vicinity of Magdeburg. Stemming from the final year of his life, this correspondence casts new light on Maier's biography, detailing his efforts to secure patronage amid the financial crisis of the early Thirty Years' War. While his ill-fated quest to perfect potable gold continued to form the central focus of his patronage suits, Maier also offered his services in several arts that he had condemned in his printed works, namely astrology and "supernatural" magic. Remarks concerning his previously unknown acquaintance with Heinrich Khunrath call for a re-evaluation of Maier's negotiation of the discursive boundaries between Lutheran orthodoxy and Paracelsianism. The letters also reveal Maier's substantial contribution to a work previously ascribed solely to the English alchemist Francis Anthony.

  6. Half a Century of Physical Review Letters

    ScienceCinema

    Garisto, Robert

    2016-07-12

    Fifty years ago, Sam Goudsmit started an experiment: the journal Physical Review Letters.  Since 1958, the experiment has thrived. PRL has gone through many changes, published many important papers, and become a leader in international scientific publication.  I will trace the rise of PRL from its early 20th century roots as "Letters to the Editor," through changes in editorial process and advents of new technology. Along the way I'll show what has gone on behind the scenes, and give a glimpse of our plans for the future.  I'll also give some advice to would-be authors and referees, illustrated with interesting correspondence we've received.

  7. The letters of John Dastin.

    PubMed

    Thiesen, Wilfred

    2008-07-01

    John Dastin, a noted alchemist who lived ca. 1300, followed the lead of many of his contemporaries and predecessors in using letters to propagate his views on alchemy. This article identifies a number of letters that Dastin wrote, and includes one text addressed to a cardinal of the city of Naples. This letter is virtually a copy of a work by Arnold of Villanova. I believe that other works ascribed to Dastin will also show a great dependence on Arnold's works. PMID:19048973

  8. Multiclass Continuous Correspondence Learning

    NASA Technical Reports Server (NTRS)

    Bue, Brian D,; Thompson, David R.

    2011-01-01

    We extend the Structural Correspondence Learning (SCL) domain adaptation algorithm of Blitzer er al. to the realm of continuous signals. Given a set of labeled examples belonging to a 'source' domain, we select a set of unlabeled examples in a related 'target' domain that play similar roles in both domains. Using these 'pivot samples, we map both domains into a common feature space, allowing us to adapt a classifier trained on source examples to classify target examples. We show that when between-class distances are relatively preserved across domains, we can automatically select target pivots to bring the domains into correspondence.

  9. Resource Letter FR-1: Fractals

    NASA Astrophysics Data System (ADS)

    Hurd, Alan J.

    1988-11-01

    This Resource Letter provides a guide to the literature on fractals. Although ``fractal'' is a relatively new term in science, unifying many new ideas with established ones, its wide application and general popularity have made it one of the fastest growing fields in statistical physics. The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field; the letter I, for intermediate level, indicates material of somewhat more specialized nature; and the letter A indicates rather specialized or advanced material. An asterisk (*) indicates those articles to be included in an accompanying Reprint Book.

  10. The Correspondence Principle Revisited.

    ERIC Educational Resources Information Center

    Liboff, Richard L.

    1984-01-01

    Addresses the question of frequency correspondence in the domain of large quantum numbers, with reference to periodic systems. Provides two simple counterexamples (a particle in a cubical box and a rigid rotator) to show that the classical result is not always recovered in the limit of large quantum numbers. (JM)

  11. Summer Correspondence Program.

    ERIC Educational Resources Information Center

    Sulphur Springs Union Elementary School District, Canyon Country, CA.

    THE FOLLOWING IS THE FULL TEXT OF THIS DOCUMENT: The goals of the Summer Correspondence Program have been to help students maintain their basic skills and avoid summer fall-out, as well as to promote parent involvement and positive community relations. After Proposition 13 left no funds for continuation of summer school programs, Sulphur Springs…

  12. What Can Reduce Letter Migrations in Letter Position Dyslexia?

    ERIC Educational Resources Information Center

    Friedmann, Naama; Rahamim, Einav

    2014-01-01

    Letter position dyslexia (LPD) is a peripheral dyslexia that causes errors of letter position within words, such as reading "cloud" as "could." In this study, we assessed the effect of various display manipulations and reading methods on the reading of 10 Hebrew readers with developmental LPD. These manipulations included…

  13. A correspondence principle

    NASA Astrophysics Data System (ADS)

    Hughes, Barry D.; Ninham, Barry W.

    2016-02-01

    A single mathematical theme underpins disparate physical phenomena in classical, quantum and statistical mechanical contexts. This mathematical "correspondence principle", a kind of wave-particle duality with glorious realizations in classical and modern mathematical analysis, embodies fundamental geometrical and physical order, and yet in some sense sits on the edge of chaos. Illustrative cases discussed are drawn from classical and anomalous diffusion, quantum mechanics of single particles and ideal gases, quasicrystals and Casimir forces.

  14. Letters in Biographies and Novels.

    ERIC Educational Resources Information Center

    Paterra, Elizabeth

    1997-01-01

    This is an annotated bibliography of biographies, historical fiction, contemporary stories, and discussion questions related to letter writing. A sidebar suggests an activity that involves reading a book about Ludwig van Beethoven, listening to Beethoven's music, and discussing letters in the story. (DGM)

  15. The Syllabic Bridge: The First Step in Learning Spelling-to-Sound Correspondences

    ERIC Educational Resources Information Center

    Doignon-Camus, Nadege; Zaga, Daniel

    2014-01-01

    It is widely agreed that learning to read starts with the establishment of letter-to-phoneme correspondences. However, it is also widely agreed that prereaders do not have access to phoneme units. Here we show that the building of associations between letters and syllables, which we call the "syllabic bridge", might be a faster and more…

  16. Correspondence: Searching sequence space

    SciTech Connect

    Youvan, D.C.

    1995-08-01

    This correspondence debates the efficiency and application of genetic algorithms (GAs) to search protein sequence space. The important experimental point is that such sparse searches utilize physically realistic syntheses. In this regard, all GA-based technologies are very similar; they {open_quotes}learn{close_quotes} from their initial sparse search and then generate interesting new proteins within a few iterations. Which GA-based technology is best? That probably depends on the protein and the specific engineering goal. Given the fact that the field of combinatorial chemistry is still in its infancy, it is probably wise to consider all of the proven mutagenesis methods. 19 refs.

  17. Feature detection and letter identification.

    PubMed

    Pelli, Denis G; Burns, Catherine W; Farell, Bart; Moore-Page, Deborah C

    2006-12-01

    Seeking to understand how people recognize objects, we have examined how they identify letters. We expected this 26-way classification of familiar forms to challenge the popular notion of independent feature detection ("probability summation"), but find instead that this theory parsimoniously accounts for our results. We measured the contrast required for identification of a letter briefly presented in visual noise. We tested a wide range of alphabets and scripts (English, Arabic, Armenian, Chinese, Devanagari, Hebrew, and several artificial ones), three- and five-letter words, and various type styles, sizes, contrasts, durations, and eccentricities, with observers ranging widely in age (3 to 68) and experience (none to fluent). Foreign alphabets are learned quickly. In just three thousand trials, new observers attain the same proficiency in letter identification as fluent readers. Surprisingly, despite this training, the observers-like clinical letter-by-letter readers-have the same meager memory span for random strings of these characters as observers seeing them for the first time. We compare performance across tasks and stimuli that vary in difficulty by pitting the human against the ideal observer, and expressing the results as efficiency. We find that efficiency for letter identification is independent of duration, overall contrast, and eccentricity, and only weakly dependent on size, suggesting that letters are identified by a similar computation across this wide range of viewing conditions. Efficiency is also independent of age and years of reading. However, efficiency does vary across alphabets and type styles, with more complex forms yielding lower efficiencies, as one might expect from Gestalt theories of perception. In fact, we find that efficiency is inversely proportional to perimetric complexity (perimeter squared over "ink" area) and nearly independent of everything else. This, and the surprisingly fixed ratio of detection and identification

  18. The Letter-Sound Generalization of First, Second, and Third Grade Finnish Children.

    ERIC Educational Resources Information Center

    Venezky, Richard L.

    To find how well children learn letter-sound correspondences when an orthography is highly regular, and how this ability relates to socioeconomic status (SES) and to reading ability, 240 Finnish children were tested for letter-sound generalizations. The test consisted of 25 synthetic words, constructed to look like Finnish words and to contain the…

  19. Effects of the spike timing-dependent plasticity on the synchronisation in a random Hodgkin-Huxley neuronal network

    NASA Astrophysics Data System (ADS)

    Borges, R. R.; Borges, F. S.; Lameu, E. L.; Batista, A. M.; Iarosz, K. C.; Caldas, I. L.; Viana, R. L.; Sanjuán, M. A. F.

    2016-05-01

    In this paper, we study the effects of spike timing-dependent plasticity on synchronisation in a network of Hodgkin-Huxley neurons. Neuron plasticity is a flexible property of a neuron and its network to change temporarily or permanently their biochemical, physiological, and morphological characteristics, in order to adapt to the environment. Regarding the plasticity, we consider Hebbian rules, specifically for spike timing-dependent plasticity (STDP), and with regard to network, we consider that the connections are randomly distributed. We analyse the synchronisation and desynchronisation according to an input level and probability of connections. Moreover, we verify that the transition for synchronisation depends on the neuronal network architecture, and the external perturbation level.

  20. [Hardware Implementation of Numerical Simulation Function of Hodgkin-Huxley Model Neurons Action Potential Based on Field Programmable Gate Array].

    PubMed

    Wang, Jinlong; Lu, Mai; Hu, Yanwen; Chen, Xiaoqiang; Pan, Qiangqiang

    2015-12-01

    Neuron is the basic unit of the biological neural system. The Hodgkin-Huxley (HH) model is one of the most realistic neuron models on the electrophysiological characteristic description of neuron. Hardware implementation of neuron could provide new research ideas to clinical treatment of spinal cord injury, bionics and artificial intelligence. Based on the HH model neuron and the DSP Builder technology, in the present study, a single HH model neuron hardware implementation was completed in Field Programmable Gate Array (FPGA). The neuron implemented in FPGA was stimulated by different types of current, the action potential response characteristics were analyzed, and the correlation coefficient between numerical simulation result and hardware implementation result were calculated. The results showed that neuronal action potential response of FPGA was highly consistent with numerical simulation result. This work lays the foundation for hardware implementation of neural network. PMID:27079105

  1. Two new species of South American freshwater crayfish genus Parastacus Huxley, 1879 (Crustacea: Decapoda: Parastacidae).

    PubMed

    Ribeiro, Felipe Bezerra; Buckup, Ludwig; Gomes, Kelly Martinez; Araujo, Paula Beatriz

    2016-01-01

    Two new species of Parastacus Huxley, 1879 are described from material collected in the state of Rio Grande do Sul, southern Brazil: Parastacus fluviatilis sp. nov. from highland streams and Parastacus caeruleodactylus sp. nov. from wetlands. Parastacus fluviatilis sp. nov. is distinguished mainly by large chelipeds with dense setae cover on the cutting edge of fingers, telson subtriangular with two lateral blunt spines and strongly concave ventral surface of lateral process of thoracic sternites 6 and 7. Parastacus caeruleodactylus sp. nov. is distinguished mainly by blue cheliped fingers and a large gap between them, reduced abdomen, dorsal and ventral margins of dactylus, propodus and carpus of second pair of pereiopods with tufts of long setae and mid-dorsal carina of exopod of uropods unarmed. According to IUCN Red List criteria both species are considered endangered. Habitat characterization and a method for defining the shape of second abdominal pleura are also provided. PMID:27615888

  2. Early predictors of letter knowledge.

    PubMed

    de Jong, P F; Olson, R K

    2004-07-01

    This study examined the influence of phonological memory and rapid naming on the development of letter knowledge. Participants were 77 Dutch children, who were followed from the start of their first kindergarten year (mean age 4 years 6.8 months) to the end of their second kindergarten year. Phonological memory was assessed by a nonword repetition test and a sentence repetition test. Rapid naming involved object naming. The study revealed found a substantial effect of phonological memory on the acquisition of letter knowledge that was particularly related to the ability to repeat nonwords. Vocabulary knowledge did not have an independent effect on letter learning after phonological memory was controlled. The study also showed a small effect of rapid naming on the acquisition of letter knowledge that was independent of the effect of phonological memory. Finally, the study also provided further evidence for a specific relation between phonological memory and vocabulary acquisition. PMID:15203300

  3. Letter from the Friends Chairman

    MedlinePlus

    ... Home Current Issue Past Issues Letter from the Friends Chairman Past Issues / Fall 2006 Table of Contents ... FNLM Chairman Paul Rogers converse at a recent Friends function at the National Library of Medicine. Photo ...

  4. A Letter to Sister Alice

    ERIC Educational Resources Information Center

    McAward, Nancy

    1976-01-01

    The author of this letter, the former principal of Dominican Academy, New York City, was concerned with leadership transmission and the role of the principal in creating a healthy atmosphere for growth. (Author/RK)

  5. Letters to a Young Writer.

    ERIC Educational Resources Information Center

    Waldman, Anne; Becker, Robin

    2002-01-01

    Presents words of encouragement to a young poet. Includes empathetic words and motivating ideas. Presents a letter including a quote from "Tintern Abbey" by William Wordsworth and ideas about that quote. (SG)

  6. Color associations for days and letters across different languages

    PubMed Central

    Rouw, Romke; Case, Laura; Gosavi, Radhika; Ramachandran, Vilayanur

    2014-01-01

    While colors are commonplace in everyday metaphors, relatively little is known about implicit color associations to linguistic or semantic concepts in a general population. In this study, we test color associations for ordered linguistic concepts (letters and days). The culture and language specificity of these effects was examined in a large group (457) of Dutch-speaking participants, 92 English-speaking participants, and 49 Hindi-speaking participants. Non-random distributions of color choices were revealed; consistencies were found across the three language groups in color preferences for both days and letters. Interestingly, while the Hindi-speaking participants were presented with letter stimuli matched on phonology, their pattern of letter-to-color preferences still showed similarities with Dutch- and English-speaking participants. Furthermore, we found that that the color preferences corresponded between participants indicating to have conscious color experiences with letters or days (putative synesthetes) and participants who do not (non-synesthetes). We also explored possible mechanisms underlying the color preferences. There were a few specific associations, including red for “A,” red for “Monday,” and white for “Sunday.” We also explored more general mechanisms, such as overall color preferences as shown by Simner et al. (2005). While certainly not all variation can be explained or predicted, the results show that regularities are present in color-to-letter or color-to-day preferences in both putative synesthetes and non-synesthetes across languages. Both letter-to-color and day-to-color preferences were influenced by multiple factors. The findings support a notion of abstract concepts (such as days and letters) that are not represented in isolation, but are connected to perceptual representational systems. Interestingly, at least some of these connections to color representations are shared across different language/cultural groups. PMID

  7. Color associations for days and letters across different languages.

    PubMed

    Rouw, Romke; Case, Laura; Gosavi, Radhika; Ramachandran, Vilayanur

    2014-01-01

    While colors are commonplace in everyday metaphors, relatively little is known about implicit color associations to linguistic or semantic concepts in a general population. In this study, we test color associations for ordered linguistic concepts (letters and days). The culture and language specificity of these effects was examined in a large group (457) of Dutch-speaking participants, 92 English-speaking participants, and 49 Hindi-speaking participants. Non-random distributions of color choices were revealed; consistencies were found across the three language groups in color preferences for both days and letters. Interestingly, while the Hindi-speaking participants were presented with letter stimuli matched on phonology, their pattern of letter-to-color preferences still showed similarities with Dutch- and English-speaking participants. Furthermore, we found that that the color preferences corresponded between participants indicating to have conscious color experiences with letters or days (putative synesthetes) and participants who do not (non-synesthetes). We also explored possible mechanisms underlying the color preferences. There were a few specific associations, including red for "A," red for "Monday," and white for "Sunday." We also explored more general mechanisms, such as overall color preferences as shown by Simner et al. (2005). While certainly not all variation can be explained or predicted, the results show that regularities are present in color-to-letter or color-to-day preferences in both putative synesthetes and non-synesthetes across languages. Both letter-to-color and day-to-color preferences were influenced by multiple factors. The findings support a notion of abstract concepts (such as days and letters) that are not represented in isolation, but are connected to perceptual representational systems. Interestingly, at least some of these connections to color representations are shared across different language/cultural groups. PMID:24904447

  8. Letters to the editor: definitely not children of a lesser god.

    PubMed

    Papanas, N; Georgiadis, G S; Maltezos, E; Lazarides, M K

    2009-10-01

    Letters to the editor are brief texts that are published in a special section of medical journals. There are two types of letters to the editor: the observation and the comment. The former presents original work, while the latter constitutes criticism on work already published in the same journal. Although short, letters to the editor require as much effort and discipline in writing as, indeed, any other manuscript. Clarity and brevity should be their principal values. It is also important to comply with the journals' instructions for correspondence. Thus, eloquent letters to the editor may promote knowledge and enable fruitful exchange of ideas.

  9. 46 CFR 115.306 - Stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Stability letter. 115.306 Section 115.306 Shipping COAST... of Certificates, Permits, and Stability Letters § 115.306 Stability letter. When, in accordance with § 170.120 in subchapter S of this chapter, a vessel must be provided with a stability letter,...

  10. 46 CFR 115.306 - Stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Stability letter. 115.306 Section 115.306 Shipping COAST... of Certificates, Permits, and Stability Letters § 115.306 Stability letter. When, in accordance with § 170.120 in subchapter S of this chapter, a vessel must be provided with a stability letter,...

  11. 46 CFR 115.306 - Stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Stability letter. 115.306 Section 115.306 Shipping COAST... of Certificates, Permits, and Stability Letters § 115.306 Stability letter. When, in accordance with § 170.120 in subchapter S of this chapter, a vessel must be provided with a stability letter,...

  12. 46 CFR 115.306 - Stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Stability letter. 115.306 Section 115.306 Shipping COAST... of Certificates, Permits, and Stability Letters § 115.306 Stability letter. When, in accordance with § 170.120 in subchapter S of this chapter, a vessel must be provided with a stability letter,...

  13. 46 CFR 115.306 - Stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Stability letter. 115.306 Section 115.306 Shipping COAST... of Certificates, Permits, and Stability Letters § 115.306 Stability letter. When, in accordance with § 170.120 in subchapter S of this chapter, a vessel must be provided with a stability letter,...

  14. Embedded Picture Mnemonics to Learn Letters

    ERIC Educational Resources Information Center

    Shmidman, Adina; Ehri, Linnea

    2010-01-01

    Can embedded mnemonics ease the task of learning a foreign alphabet? English-speaking preschoolers (N = 36, M = 5;2 years) were taught 10 Hebrew letter-sound relations. Experimental letters were learned with mnemonics that embedded letter shapes in drawings of objects whose shapes resembled the letters and whose English names began with the…

  15. Language General and Specific Factors in Letter Acquisition: Considering Child and Letter Characteristics in Korean

    ERIC Educational Resources Information Center

    Kim, Young-Suk; Petscher, Yaacov

    2013-01-01

    In the present study we investigated the extent to which child level factors (i.e., phonological awareness) and letter level factors (i.e., letter name structures, letter frequency, visual similarity, and letter order) contributed to letter name and sound acquisition, using data from Korean-speaking children (N = 169) and cross-classified…

  16. Effects of Letter-Identification Training on Letter Naming in Prereading Children

    ERIC Educational Resources Information Center

    Hayashi, Yusuke; Schmidt, Anna C.; Saunders, Kathryn J.

    2013-01-01

    Three prereading children who named 0 to 3 of 20 targeted letters were taught to select the 20 printed letters when they heard spoken letter names. For all participants, letter-identification training resulted in naming for the majority of letters.

  17. 76 FR 9338 - List of Correspondence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... Topic Addressed: Independent Educational Evaluations Letter dated August 13, 2010 to individuals...: Least Restrictive Environment Letter dated August 23, 2010 to Conference of Educational Administrators... considered in determining placement for students who are deaf. SECTION 614--Evaluations,...

  18. Letters from ainsworth: contesting the 'organization' of attachment.

    PubMed

    Landa, Sophie; Duschinsky, Robbie

    2013-05-01

    As Main (1999) noted in her obituary for Mary Ainsworth, 'she was interacting weekly by letter and manuscript with her mentor and friend, John Bowlby, and their academic correspondence formed an important part of her, and implicitly our, life.' These letters of Ainsworth to John Bowlby during the 1980s, available in the Wellcome Trust Library in London, contain valuable reflections on the work of her pupils to extend her system of classifying infant behaviour in the Strange Situation Procedure. Mary Main proposed a D classification and interpreted such behaviour as a breakdown in an ABC strategy caused by a conflict between a disposition to approach and flee from the caregiver. Patricia Crittenden extended the subtypes of A and C, using a developmental model of information processing, and observed that they could be used together in A/C combinations. These letters offer insight into Ainsworth's intellectual rationale for encouraging both Main and Crittenden in their conflicting endeavours.

  19. The Lyttleton-Hoyle correspondence 1939-42

    NASA Astrophysics Data System (ADS)

    Mitton, S.

    2005-12-01

    Fred Hoyle started to collaborate with his older colleague Raymond Lyttleton in 1938. Hoyle's doctoral research had been in nuclear physics, and his supervisors were Rudolph Peierls and Paul Dirac. His first papers were in quantum electrodynamics. When Hoyle decided to change his research field to astronomy, Lyttleton acted as a mentor, and it was he who suggested that Hoyle should look at the physics of accretion. From late-1939, Lyttleton and Hoyle were both scientific civil servants drafted in for war work. They were in different establishments and could communicate only by the postal service. Some 70 letters from Lyttleton to Hoyle have survived, but we do not have any copies of Hoyle's correspondence. Many letters are undated, so it required detective work to assemble them in the correct sequence. The correspondence shows that Lyttleton played the senior role in determining what problems they should tackle, and in what order. Apart from the scientific content, these letters are remarkable for the sharp personal remarks Lyttleton makes of other colleagues, and particularly the Council of the Royal Astronomical Society. I make the suggestion that the poisonous and prolonged nature of the correspondence considerably influenced Hoyle's subsequent attitude to the establishment, to government-employed astronomers, and to the RAS. This was detrimental when Hoyle found, later in his career, that he would have to provide answers to these stakeholders. This research has been supported by St Edmund's College, Cambridge, UK.

  20. CLEMAPS: multiple alignment of protein structures based on conformational letters.

    PubMed

    Liu, Xin; Zhao, Ya-Pu; Zheng, Wei-Mou

    2008-05-01

    CLEMAPS is a tool for multiple alignment of protein structures. It distinguishes itself from other existing algorithms for multiple structure alignment by the use of conformational letters, which are discretized states of 3D segmental structural states. A letter corresponds to a cluster of combinations of three angles formed by C(alpha) pseudobonds of four contiguous residues. A substitution matrix called CLESUM is available to measure the similarity between any two such letters. The input 3D structures are first converted to sequences of conformational letters. Each string of a fixed length is then taken as the center seed to search other sequences for neighbors of the seed, which are strings similar to the seed. A seed and its neighbors form a center-star, which corresponds to a fragment set of local structural similarity shared by many proteins. The detection of center-stars using CLESUM is extremely efficient. Local similarity is a necessary, but insufficient, condition for structural alignment. Once center-stars are found, the spatial consistency between any two stars are examined to find consistent star duads using atomic coordinates. Consistent duads are later joined to create a core for multiple alignment, which is further polished to produce the final alignment. The utility of CLEMAPS is tested on various protein structure ensembles.

  1. Resource Letter N-1: Nanotechnology

    NASA Astrophysics Data System (ADS)

    Cela, Devin; Dresselhaus, Mildred; Helen Zeng, Tingying; Terrones, Mauricio; Souza Filho, Antonio G.; Ferreira, Odair P.

    2014-01-01

    This Resource Letter provides a guide to the literature on Nanotechnology. Journal articles, books, websites, and other documents are cited on the following topics: attributes of various types of nanomaterials, nanotechnology in the context of different academic fields, and the effects of nanotechnology on society.

  2. The Harvard Education Letter, 1995.

    ERIC Educational Resources Information Center

    Miller, Edward, Ed.

    1995-01-01

    This document is comprised of volume 11 of the Harvard Education Letter, published bimonthly and addressing current issues in elementary and secondary education. Articles in the volume's six issues are: (1) January-February--"The Old Model of Staff Development Survives in a World Where Everything Else Has Changed" (Miller), "Giving Voice to Our…

  3. Curriculum Vitae and Related Letters.

    ERIC Educational Resources Information Center

    Peterson, Sharyl Bender

    This booklet, which was developed by a college career center, explains the purpose of and procedures for writing curriculum vitae (CV) and related letters. The following topics are covered: when a CV is appropriate, points to consider when writing a CV, items usually included, possible sections to include in a CV, and steps in writing cover…

  4. Resource Letter Sol-1: Solitons

    NASA Astrophysics Data System (ADS)

    Degasperis, Antonio

    1998-06-01

    This Resource Letter provides a guide to the literature on the theory of solitons and its relevance in physics. Journal articles and books are cited for the following topics: the history of solitons, construction of soliton equations and of soliton solutions, solitons and mathematics, quantum solitons, solitons in physics and near-integrable equations.

  5. The Principal and Reference Letters.

    ERIC Educational Resources Information Center

    Smith, Agnes E.; Permuth, Steve; Gray, David L.

    1999-01-01

    Requests to write letters of reference for former teachers can be legally problematic. Principals should know relevant state laws; have employees sign a release from liability; provide only factual information; maintain fair personnel files; avoid telephone recommendations; disclose information on a need-to-know basis; and avoid performance…

  6. "The Scarlet Letter". [Lesson Plan].

    ERIC Educational Resources Information Center

    Discovery Communications, Inc., Bethesda, MD.

    Based on Nathaniel Hawthorne's novel "The Scarlet Letter," this lesson plan presents activities designed to help students understand that the ending of a novel does not resolve all of the questions that may occur to readers; and that readers may imagine characters living out their lives beyond the ending the author gave to a novel. The main…

  7. The Harvard Education Letter, 1996.

    ERIC Educational Resources Information Center

    Miller, Edward Ed.; Graves-Desai, Kelly, Ed.; Maloney, Karen, Ed.

    1996-01-01

    This document is comprised of volume 12 of the Harvard Education Letter, published bimonthly and addressing current issues in elementary-secondary education. Articles in this volume include the following: (1) January-February--"Early Reports From Kentucky on Cash Rewards for 'Successful' Schools Reveal Many Problems" (Miller), "New Ideas Like…

  8. A Letter to My Mother.

    ERIC Educational Resources Information Center

    Daisley, Margaret

    In a letter to her mother, herself a former English teacher, a teaching assistant details impressions of her first year in the Writing Program at the University of Massachusetts (Amherst). During a semester an instructor gets to know writing students individually in a way that pierces deeply through the veneer of stereotype. The class published…

  9. Resource Letter RC-1: Cosmology

    ERIC Educational Resources Information Center

    Ryan, Michael P., Jr.; Shepley, L. C.

    1976-01-01

    This is one of a series of resource letters on different topics intended to guide college physicists, astronomers, and other scientists to some of the literature and other teaching aids that may help improve course content in specified fields. (Author/CP)

  10. Resumes, Applications, and Cover Letters

    ERIC Educational Resources Information Center

    Crosby, Olivia

    2009-01-01

    Good resumes, applications, and cover letters broadcast one's abilities. They tell employers how one's qualifications match a job's responsibilities. If these critical preliminaries are constructed well, one has a better chance of landing interviews--and, eventually, a job. This article provides some guidelines for creating resumes and cover…

  11. The Harvard Education Letter, 1998.

    ERIC Educational Resources Information Center

    Graves-Desai, Kelly, Ed.; Eaton, Susan, Ed.; Walser, Nancy, Ed.

    1998-01-01

    This document is comprised of volume 14 of the Harvard Education Letter, published bimonthly and addressing current issues in elementary and secondary education. Articles in the six issues of this volume include the following: (1) January-February--"Multi-Age Classrooms: An Age-Old Grouping Method Is Still Evolving" (Walser), "Teachers Wanted:…

  12. Updated Principle of Corresponding States

    ERIC Educational Resources Information Center

    Ben-Amotz, Dor; Gift, Alan D.; Levine, R. D.

    2004-01-01

    The rule of corresponding states, which shows the connection between the thermodynamic properties of various liquids is re-examined. The overall likeness is observed by using an updated scaling technique of Lennard-Jones corresponding states (LJ-CS).

  13. 48 CFR 816.7001 - Letters of availability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... commitment. Prospective contractors sometimes solicit letters of availability or the letters may originate... letter of availability lacks procurement authority, the prospective contractor may incur...

  14. CORRESPONDENCE EDUCATION IN THE NETHERLANDS.

    ERIC Educational Resources Information Center

    SLOOS, ISAAEC; AND OTHERS

    RECENT TRENDS AND EVIDENCES OF PROGRESS IN CORRESPONDENCE EDUCATION IN THE NETHERLANDS ARE CONSIDERED, TOGETHER WITH RESEARCH ON THE SOCIOCULTURAL AND MOTIVATIONAL ASPECTS OF PARTICIPATION IN CORRESPONDENCE STUDY, AND THE SPECIAL FUNCTIONS AND ADVANTAGES OF THE CORRESPONDENCE METHOD. THEORIES AND IDEAS UNDERLYING THE DIDACTICS OF CORRESPONDENCE…

  15. Effects of stimulus duration and inter-letter spacing on letter-in-string identification.

    PubMed

    Marzouki, Yousri; Grainger, Jonathan

    2014-05-01

    Effects of stimulus duration and inter-letter spacing were studied in a letter-in-string identification paradigm. Participants were shown strings of 5 random consonants (e.g., PGKDM) centered on fixation and were asked to identify the letter that had appeared at a post-cued location. Stimulus duration was manipulated in Experiment 1 (13 ms-91 ms), and inter-letter spacing manipulated in Experiment 2 (for a fixed stimulus duration of 26 ms). We contrasted performance to outer-letters (positions 1 and 5) with non-central inner letters (positions 2 and 4), the first-letter (position 1) with the final letter (position 5), and the central-letter (position 3) with the other inner letters (positions 2 and 4). The outer-letter advantage and the first-letter advantage were present throughout the entire range of exposure durations, whereas the central-letter advantage increased with longer exposures. On the other hand, increased spacing reduced both the outer-letter advantage and the first-letter advantage, whereas it led to a greater central-letter advantage. Changes in acuity and crowding as a function of stimulus exposure and inter-letter spacing, can account for this pattern of results.

  16. Spontaneous voltage oscillations and response dynamics of a Hodgkin-Huxley type model of sensory hair cells

    PubMed Central

    2011-01-01

    We employ a Hodgkin-Huxley-type model of basolateral ionic currents in bullfrog saccular hair cells for studying the genesis of spontaneous voltage oscillations and their role in shaping the response of the hair cell to external mechanical stimuli. Consistent with recent experimental reports, we find that the spontaneous dynamics of the model can be categorized using conductance parameters of calcium-activated potassium, inward rectifier potassium, and mechano-electrical transduction (MET) ionic currents. The model is demonstrated for exhibiting a broad spectrum of autonomous rhythmic activity, including periodic and quasi-periodic oscillations with two independent frequencies as well as various regular and chaotic bursting patterns. Complex patterns of spontaneous oscillations in the model emerge at small values of the conductance of Ca2+-activated potassium currents. These patterns are significantly affected by thermal fluctuations of the MET current. We show that self-sustained regular voltage oscillations lead to enhanced and sharply tuned sensitivity of the hair cell to weak mechanical periodic stimuli. While regimes of chaotic oscillations are argued to result in poor tuning to sinusoidal driving, chaotically oscillating cells do provide a high sensitivity to low-frequency variations of external stimuli. PMID:22282726

  17. Analysis of the optimal channel density of the squid giant axon using a reparameterized Hodgkin-Huxley model.

    PubMed

    Sangrey, Thomas D; Friesen, W Otto; Levy, William B

    2004-06-01

    A reparameterized Hodgkin-Huxley-type model is developed that improves the 1952 model's fit to the biological action potential. In addition to altering Na(+) inactivation and K(+) activation kinetics, a voltage-dependent gating-current mechanism has been added to the model. The resulting improved model fits the experimental trace nearly exactly over the rising phase, and it has a propagation velocity that is within 3% of the experimentally measured value of 21.2 m/s (at 18.5 degrees C). Having eliminated most inaccuracies associated with the velocity-dependent rising phase of the action potential, the model is used to test Hodgkin's maximum velocity hypothesis, which asserts that channel density has evolved to maximize conduction velocity. In fact the predicted optimal channel density is more than twice as high as the actual squid channel density. When the available capacitance is reduced to approximate more modern serial Na(+)-channel models, the optimal channel density is 4 times the actual value. We suggest that, although Hodgkin's maximum velocity hypothesis is acceptable as a first approximation, the microscopic optimization perspective of natural selection will not explain the channel density of the squid unless other constraints are taken into account, for example, the metabolic costs of velocity.

  18. A simple modification of the Hodgkin and Huxley equations explains type 3 excitability in squid giant axons.

    PubMed

    Clay, John R; Paydarfar, David; Forger, Daniel B

    2008-12-01

    The Hodgkin and Huxley (HH) model predicts sustained repetitive firing of nerve action potentials for a suprathreshold depolarizing current pulse for as long as the pulse is applied (type 2 excitability). Squid giant axons, the preparation for which the model was intended, fire only once at the beginning of the pulse (type 3 behaviour). This discrepancy between the theory and experiments can be removed by modifying a single parameter in the HH equations for the K+ current as determined from the analysis in this paper. K+ currents in general have been described by IK=gK(V-EK), where gK is the membrane's K+ current conductance and EK is the K+ Nernst potential. However, IK has a nonlinear dependence on (V-EK) well described by the Goldman-Hodgkin-Katz equation that determines the voltage dependence of gK. This experimental finding is the basis for the modification in the HH equations describing type 3 behaviour. Our analysis may have broad significance given the use of IK=gK(V-EK) to describe K+ currents in a wide variety of biological preparations.

  19. Optimal size of stochastic Hodgkin-Huxley neuronal systems for maximal energy efficiency in coding pulse signals.

    PubMed

    Yu, Lianchun; Liu, Liwei

    2014-03-01

    The generation and conduction of action potentials (APs) represents a fundamental means of communication in the nervous system and is a metabolically expensive process. In this paper, we investigate the energy efficiency of neural systems in transferring pulse signals with APs. By analytically solving a bistable neuron model that mimics the AP generation with a particle crossing the barrier of a double well, we find the optimal number of ion channels that maximizes the energy efficiency of a neuron. We also investigate the energy efficiency of a neuron population in which the input pulse signals are represented with synchronized spikes and read out with a downstream coincidence detector neuron. We find an optimal number of neurons in neuron population, as well as the number of ion channels in each neuron that maximizes the energy efficiency. The energy efficiency also depends on the characters of the input signals, e.g., the pulse strength and the interpulse intervals. These results are confirmed by computer simulation of the stochastic Hodgkin-Huxley model with a detailed description of the ion channel random gating. We argue that the tradeoff between signal transmission reliability and energy cost may influence the size of the neural systems when energy use is constrained.

  20. Membrane Capacitive Memory Alters Spiking in Neurons Described by the Fractional-Order Hodgkin-Huxley Model

    PubMed Central

    Weinberg, Seth H.

    2015-01-01

    Excitable cells and cell membranes are often modeled by the simple yet elegant parallel resistor-capacitor circuit. However, studies have shown that the passive properties of membranes may be more appropriately modeled with a non-ideal capacitor, in which the current-voltage relationship is given by a fractional-order derivative. Fractional-order membrane potential dynamics introduce capacitive memory effects, i.e., dynamics are influenced by a weighted sum of the membrane potential prior history. However, it is not clear to what extent fractional-order dynamics may alter the properties of active excitable cells. In this study, we investigate the spiking properties of the neuronal membrane patch, nerve axon, and neural networks described by the fractional-order Hodgkin-Huxley neuron model. We find that in the membrane patch model, as fractional-order decreases, i.e., a greater influence of membrane potential memory, peak sodium and potassium currents are altered, and spike frequency and amplitude are generally reduced. In the nerve axon, the velocity of spike propagation increases as fractional-order decreases, while in a neural network, electrical activity is more likely to cease for smaller fractional-order. Importantly, we demonstrate that the modulation of the peak ionic currents that occurs for reduced fractional-order alone fails to reproduce many of the key alterations in spiking properties, suggesting that membrane capacitive memory and fractional-order membrane potential dynamics are important and necessary to reproduce neuronal electrical activity. PMID:25970534

  1. Teaching and learning the Hodgkin-Huxley model based on software developed in NEURON’s programming language hoc

    PubMed Central

    2013-01-01

    Background We present a software tool called SENB, which allows the geometric and biophysical neuronal properties in a simple computational model of a Hodgkin-Huxley (HH) axon to be changed. The aim of this work is to develop a didactic and easy-to-use computational tool in the NEURON simulation environment, which allows graphical visualization of both the passive and active conduction parameters and the geometric characteristics of a cylindrical axon with HH properties. Results The SENB software offers several advantages for teaching and learning electrophysiology. First, SENB offers ease and flexibility in determining the number of stimuli. Second, SENB allows immediate and simultaneous visualization, in the same window and time frame, of the evolution of the electrophysiological variables. Third, SENB calculates parameters such as time and space constants, stimuli frequency, cellular area and volume, sodium and potassium equilibrium potentials, and propagation velocity of the action potentials. Furthermore, it allows the user to see all this information immediately in the main window. Finally, with just one click SENB can save an image of the main window as evidence. Conclusions The SENB software is didactic and versatile, and can be used to improve and facilitate the teaching and learning of the underlying mechanisms in the electrical activity of an axon using the biophysical properties of the squid giant axon. PMID:23675833

  2. Letter to Russia

    SciTech Connect

    Tobin, J G

    2012-03-15

    find it puzzling that the authors nonetheless claim in their conclusions that 'An evaluation of state occupations supports the proposal that the occupation of the 5f levels in bulk Pu must be near 5'. Apart from the aforementioned conceptual inconsistencies, there are a number of more technical aspects that are not discussed in sufficient detail. Among these are: (1) The authors use LDA to approximate the electron correlations. A lively debate takes place in the literature whether this approximation can adequately describe the electronic structure of Pu metal or not, yet the authors do not discuss the choice of the approximation at all, which they should, in my opinion. They should also specify if their solutions are spin polarized or whether they use spin-restricted LDA. (2) The quality of the employed basis set is not clear. Are the results converged with respect to the basis size? What is the estimated magnitude of the residual errors? (3) There are statements in the manuscript indicating that the cluster calculations depend somehow on the calculations of the diatomic molecule. Namely: 'Underpinning these calculations, there is a geometry optimization of diatomic molecules...' and 'Underlying the Pu cluster simulations is the calculation of the electronic structure of a Pu2 dimer with the bond length 3.28 {angstrom} corresponding to the inter-atomic distances in delta-Pu.' What does this underpinning/underlying mean in more technical terms? What role does the geometry optimization play when the cluster calculations seem to be performed at a fixed geometry corresponding to the delta-Pu? Lastly, the manuscript contains a lot of material that was previously (and often multiple times) published elsewhere, including the Physical Review journals. For instance, the experimental part of Fig. 2 was shown already in Refs. 26, 27 and 28 in essentially the same graphical form; the top part of Fig. 9 appeared in Refs. 19, 4 and in PRL 90, 196404 (2003). I think that reprinting

  3. Letters of Reprimand: The Important Questions.

    ERIC Educational Resources Information Center

    Zirkel, Perry A.; Gluckman, Ivan B.

    1986-01-01

    Outlines two legal cases involving letters of reprimand written by administrators and put in teachers' files. Shows how in these cases the letters did not constitute defamation or a violation of First or Fourteenth Amendment rights. (MD)

  4. FROM THE HISTORY OF PHYSICS: Correspondence between G A Gamow and P L Kapitza

    NASA Astrophysics Data System (ADS)

    Frenkel', Viktor Ya

    1994-08-01

    The letters exchanged between Peter Kapitza and George Gamow are published here for the first time. The correspondence throws light on the active support accorded by Kapitza to his Russian colleagues and on his work as the coeditor of a prestigious series of physics monographs published by Clarendon Press, Oxford. Gamow comes over in his letters, relating to one of the most interesting periods of his creative activity (1929 - 1934), in full blaze of his personality.

  5. Similar Sound Separation and Cumulative Introduction in Learning Letter-Sound Correspondences

    ERIC Educational Resources Information Center

    Carnine, Douglas W.

    1976-01-01

    Since similarity inhibits learning, children will have greater difficulty learning responses that are more similar to each other; the instructional procedure of separating similar sounds was evaluated in two experiments. (DMT)

  6. Teaching Letter-Sound Correspondence to Students with Moderate Intellectual Disabilities

    ERIC Educational Resources Information Center

    Flores, Margaret M.; Shippen, Margaret E.; Alberto, Paul; Crowe, Lee

    2004-01-01

    This study examined the efficacy of systematic and explicit instruction in phonic decoding for 6 elementary students with moderate intellectual disabilities. A multiple probe across behaviors with embedded changing conditions design was employed in order to analyze the effect of Direct Instruction on teaching the following skills with regard to…

  7. Finland, Phonics, and Whole Language: Beginning Reading in a Regular Letter-Sound Correspondence Language.

    ERIC Educational Resources Information Center

    Korkeamaki, Riitta-Liisa; Dreher, Mariam Jean

    1993-01-01

    Reviews the typical approach (synthetic phonics) to teaching reading in Finland. Suggests that teachers in English-speaking countries can learn from problems Finnish teachers face and vice versa. Finds that, despite a highly regular writing system, Finnish teachers find that a heavy phonics emphasis does not solve their reading instruction…

  8. Written Communications Simulation: Write Me a Letter.

    ERIC Educational Resources Information Center

    North Carolina State Dept. of Public Instruction, Raleigh. Div. of Vocational Education.

    This simulation is intended for use as a culminating activity after students have been exposed to personal and/or business letter writing, use of reference manuals, typing of letters, mailing procedures, typing of numbers, punctuation practice, and filing procedures. Stated objectives are to enable students to type a mailable letter; to inspect,…

  9. Letter Knowledge in Parent-Child Conversations

    ERIC Educational Resources Information Center

    Robins, Sarah; Treiman, Rebecca; Rosales, Nicole

    2014-01-01

    Learning about letters is an important component of emergent literacy. We explored the possibility that parent speech provides information about letters, and also that children's speech reflects their own letter knowledge. By studying conversations transcribed in CHILDES (MacWhinney, 2000) between parents and children aged one to five, we…

  10. 24 CFR 200.1505 - Warning letter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... URBAN DEVELOPMENT GENERAL INTRODUCTION TO FHA PROGRAMS Multifamily Accelerated Processing (MAP): MAP... letter, which specifies problems or violations identified by HUD, to a MAP lender. (b) Effect of warning letter. The warning letter: (1) Does not suspend a lender's MAP privileges; (2) May impose a higher...

  11. 46 CFR 176.306 - Stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Stability letter. 176.306 Section 176.306 Shipping COAST...) INSPECTION AND CERTIFICATION Posting of Certificates, Permits, and Stability Letters § 176.306 Stability letter. When, in accordance with § 178.210 of this chapter, a vessel must be provided with a...

  12. 46 CFR 176.306 - Stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Stability letter. 176.306 Section 176.306 Shipping COAST...) INSPECTION AND CERTIFICATION Posting of Certificates, Permits, and Stability Letters § 176.306 Stability letter. When, in accordance with § 178.210 of this chapter, a vessel must be provided with a...

  13. 46 CFR 176.306 - Stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Stability letter. 176.306 Section 176.306 Shipping COAST...) INSPECTION AND CERTIFICATION Posting of Certificates, Permits, and Stability Letters § 176.306 Stability letter. When, in accordance with § 178.210 of this chapter, a vessel must be provided with a...

  14. 46 CFR 176.306 - Stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Stability letter. 176.306 Section 176.306 Shipping COAST...) INSPECTION AND CERTIFICATION Posting of Certificates, Permits, and Stability Letters § 176.306 Stability letter. When, in accordance with § 178.210 of this chapter, a vessel must be provided with a...

  15. 46 CFR 176.306 - Stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Stability letter. 176.306 Section 176.306 Shipping COAST...) INSPECTION AND CERTIFICATION Posting of Certificates, Permits, and Stability Letters § 176.306 Stability letter. When, in accordance with § 178.210 of this chapter, a vessel must be provided with a...

  16. Beyond Zebra: Preschoolers' Knowledge about Letters.

    ERIC Educational Resources Information Center

    Treiman, Rebecca; Richmond-Welty, E. Daylene; Tincoff, Ruth

    1997-01-01

    Argues that an important type of child knowledge about letters is knowledge of the phonological structure of the letters' names in English. Concludes that learning the alphabet forms the basis for generalizations about the structure of letter names. (22 references) (Author/CK)

  17. An Attempt to Simulate Letter-by-Letter Dyslexia in Normal Readers

    ERIC Educational Resources Information Center

    Fiset, Stephanie; Arguin, Martin; Fiset, Daniel

    2006-01-01

    We attempted to simulate the main features of letter-by-letter (LBL) dyslexia in normal readers through stimulus degradation (i.e. contrast reduction and removal of high spatial frequencies). The results showed the word length and the letter confusability effects characteristic of LBL dyslexia. However, the interaction of letter confusability and…

  18. What Do Letter Migration Errors Reveal About Letter Position Coding in Visual Word Recognition?

    ERIC Educational Resources Information Center

    Davis, Colin J.; Bowers, Jeffrey S.

    2004-01-01

    Dividing attention across multiple words occasionally results in misidentifications whereby letters apparently migrate between words. Previous studies have found that letter migrations preserve within-word letter position, which has been interpreted as support for position-specific letter coding. To investigate this issue, the authors used word…

  19. Learning Letter Names and Sounds: Effects of Instruction, Letter Type, and Phonological Processing Skill

    ERIC Educational Resources Information Center

    Piasta, Shayne B.; Wagner, Richard K.

    2010-01-01

    Preschool-age children (N = 58) were randomly assigned to receive instruction in letter names and sounds, letter sounds only, or numbers (control). Multilevel modeling was used to examine letter name and sound learning as a function of instructional condition and characteristics of both letters and children. Specifically, learning was examined in…

  20. Spatio-temporal properties of letter crowding

    PubMed Central

    Chung, Susana T. L.

    2016-01-01

    Crowding between adjacent letters has been investigated primarily as a spatial effect. The purpose of this study was to investigate the spatio-temporal properties of letter crowding. Specifically, we examined the systematic changes in the degradation effects in letter identification performance when adjacent letters were presented with a temporal asynchrony, as a function of letter separation and between the fovea and the periphery. We measured proportion-correct performance for identifying the middle target letter in strings of three lowercase letters at the fovea and 10° in the inferior visual field, for a range of center-to-center letter separations and a range of stimulus onset asynchronies (SOA) between the target and flanking letters (positive SOAs: target preceded flankers). As expected, the accuracy for identifying the target letters reduces with decreases in letter separation. This crowding effect shows a strong dependency on SOAs, such that crowding is maximal between 0 and ∼100 ms (depending on conditions) and diminishes for larger SOAs (positive or negative). Maximal crowding does not require the target and flanking letters to physically coexist for the entire presentation duration. Most importantly, crowding can be minimized even for closely spaced letters if there is a large temporal asynchrony between the target and flankers. The reliance of letter identification performance on SOAs and how it changes with letter separations imply that the crowding effect can be traded between space and time. Our findings are consistent with the notion that crowding should be considered as a spatio-temporal, and not simply a spatial, effect. PMID:27088895

  1. Spatio-temporal properties of letter crowding.

    PubMed

    Chung, Susana T L

    2016-01-01

    Crowding between adjacent letters has been investigated primarily as a spatial effect. The purpose of this study was to investigate the spatio-temporal properties of letter crowding. Specifically, we examined the systematic changes in the degradation effects in letter identification performance when adjacent letters were presented with a temporal asynchrony, as a function of letter separation and between the fovea and the periphery. We measured proportion-correct performance for identifying the middle target letter in strings of three lowercase letters at the fovea and 10° in the inferior visual field, for a range of center-to-center letter separations and a range of stimulus onset asynchronies (SOA) between the target and flanking letters (positive SOAs: target preceded flankers). As expected, the accuracy for identifying the target letters reduces with decreases in letter separation. This crowding effect shows a strong dependency on SOAs, such that crowding is maximal between 0 and ∼100 ms (depending on conditions) and diminishes for larger SOAs (positive or negative). Maximal crowding does not require the target and flanking letters to physically coexist for the entire presentation duration. Most importantly, crowding can be minimized even for closely spaced letters if there is a large temporal asynchrony between the target and flankers. The reliance of letter identification performance on SOAs and how it changes with letter separations imply that the crowding effect can be traded between space and time. Our findings are consistent with the notion that crowding should be considered as a spatio-temporal, and not simply a spatial, effect.

  2. Resource Letter Scy-3: Superconductivity

    NASA Astrophysics Data System (ADS)

    Butch, N. P.; de Andrade, M. C.; Maple, M. B.

    2008-02-01

    This Resource Letter provides a guide to the literature on superconductivity. Since the last Resource Letter on superconductivity, Scy-2, was published in 1970, there have been dramatic advances in our basic understanding of superconductivity, discovery of new superconducting materials, and improved technological exploitation of superconductors. We review basic phenomenology, followed by concise descriptions of several main classes of superconductors recognized today. Journal articles and books are cited for the following topics: Conventional superconductors, paramagnetic impurities in superconductors, magnetically ordered superconductors, heavy fermion superconductors, high Tc superconductors, organic superconductors, applications of superconductivity, and laboratory demonstrations of superconductivity. Owing to the large volume of available literature on superconductivity, the journal articles and books we discuss constitute good starting points for further exploration of particular topics.

  3. 50 years of JETP Letters

    NASA Astrophysics Data System (ADS)

    Pastukhov, V. P.

    2015-04-01

    This paper briefly traces the 50-year history of the journal Pis'ma v Zhurnal Eksperimental'noi i Teoreticheskoi Fiziki (JETP Letters), whose first issue was published on 1 April 1965. The journal is intended for a wide circle of physicists-readers as a fast publication channel for short communications on new results from research of the highest significance and highest priority in all areas of experimental and theoretical physics. Today, the journal celebrates numerous important contributions to the development of physics both in Russia and worldwide. Over a historically short period, JETP Letters developed into a highly authoritative and influential source for physicists engaged in a wide range of fields. Due to the wise and well-timed editorial policy, the journal continues to retain its leadership position, despite the difficulties the entire science periodical literature - and indeed the whole of science - is currently experiencing in Russia.

  4. Texture-Based Correspondence Display

    NASA Technical Reports Server (NTRS)

    Gerald-Yamasaki, Michael

    2004-01-01

    Texture-based correspondence display is a methodology to display corresponding data elements in visual representations of complex multidimensional, multivariate data. Texture is utilized as a persistent medium to contain a visual representation model and as a means to create multiple renditions of data where color is used to identify correspondence. Corresponding data elements are displayed over a variety of visual metaphors in a normal rendering process without adding extraneous linking metadata creation and maintenance. The effectiveness of visual representation for understanding data is extended to the expression of the visual representation model in texture.

  5. Van Gogh's disease in the light of his correspondence.

    PubMed

    Voskuil, Piet H A

    2013-01-01

    The literary quality of Vincent van Gogh's correspondence is widely recognized. He wrote expressively and evocatively, and had great literary knowledge. In this essay we follow his medical history in many quotes from in his letters to see how Vincent expressed his complaints, knowledge, and emotions connected with his disease. The symptoms became most clear after December 1888. In the beginning, Van Gogh hesitated to tell much about his ailment, but gradually painted in the letters his experiences, making use of the intermittent course of his cycloid psychoses. We will see an indication that, in the network that mediated Van Gogh's brain (dys)function, elements of synesthesia, prosopagnosia, and spatial agnosia might have been activated. Van Gogh's affinity for poetry, already in his early twenty's, makes the hypothesis of a, by epileptic discharges, kindled temporal lobe at most only part of the complex interpretation of this creative and suffering mind.

  6. Synesthesia for manual alphabet letters and numeral signs in second-language users of signed languages.

    PubMed

    Atkinson, Joanna; Lyons, Tanya; Eagleman, David; Woll, Bencie; Ward, Jamie

    2016-08-01

    Many synesthetes experience colors when viewing letters or digits. We document, for the first time, an analogous phenomenon among users of signed languages who showed color synesthesia for fingerspelled letters and signed numerals. Four synesthetes experienced colors when they viewed manual letters and numerals (in two cases, colors were subjectively projected on to the hands). There was a correspondence between the colors experienced for written graphemes and their manual counterparts, suggesting that the development of these two types of synesthesia is interdependent despite the fact that these systems are superficially distinct and rely on different perceptual recognition mechanisms in the brain. PMID:27351751

  7. Synesthesia for manual alphabet letters and numeral signs in second-language users of signed languages.

    PubMed

    Atkinson, Joanna; Lyons, Tanya; Eagleman, David; Woll, Bencie; Ward, Jamie

    2016-08-01

    Many synesthetes experience colors when viewing letters or digits. We document, for the first time, an analogous phenomenon among users of signed languages who showed color synesthesia for fingerspelled letters and signed numerals. Four synesthetes experienced colors when they viewed manual letters and numerals (in two cases, colors were subjectively projected on to the hands). There was a correspondence between the colors experienced for written graphemes and their manual counterparts, suggesting that the development of these two types of synesthesia is interdependent despite the fact that these systems are superficially distinct and rely on different perceptual recognition mechanisms in the brain.

  8. Thoughts on the condolence letter.

    PubMed

    Feldmann, B M

    2000-11-15

    Genuine, specific, timely emotional support of caregivers at the time of euthanasia is an important part of the veterinary professional obligation. Such support helps ease client pain during the grieving process. However, caution and sensitivity are essential when assessing and responding to caregiver-companion animal relationships.(1) For example, some caregivers are highly bonded but conceal their emotions, so our perceptions and responses must be thoughtful and discerning. My veterinary technician and I are supportive of our clients during euthanasia. I later write the condolence letter according to our perceptions of that particular human-companion animal bond. The only exceptions to our attempt to be thoroughly supportive at the time of euthanasia are those instances when we perceive that there has been obvious and willful abuse or neglect. At such times, we try to maintain emotional neutrality. The condolence letter and its variations described here are intended to serve as a guide. We send the condolence letter to caregivers within 24 hours of euthanasia, and it is addressed to the entire family. In addition, a euthanasia packet is provided at the time of euthanasia. The packet includes 2 brochures on coping with the loss of a companion animal, (2,3) contact information for a pet loss support hotline and a pet loss support group, an essay and a poem about the death of a companion animal, and a how-to article on dealing with children and their emotions on the loss of a pet. (4) My veterinary technician almost always phones the caregiver 1 to 3 days after euthanasia of their companion animal. The timing of the call depends on the circumstances of death and our judgment as to the emotional needs of the caregiver and family. Where emotions around euthanasia and loss are especially deep, the follow-up call may be made as early as that night or the next morning, with a second call 2 to 3 days later. The nature of the conversation depends on the technician

  9. Dynamical properties of neural network model for working memory with Hodgkin-Huxley neurons

    NASA Astrophysics Data System (ADS)

    Omori, Toshiaki; Horiguchi, Tsuyoshi

    2004-03-01

    We propose a neural network model of working memory with one-compartmental neurons and investigate its dynamical properties. We assume that the model consists of excitatory neurons and inhibitory neurons; all the neurons are connected to each other. The excitatory neurons are distinguished as several groups of selective neurons and one group of non-selective neurons. The selective neurons are assumed to form subpopulations in which each selective neuron belongs to only one of subpopulations. The non-selective neurons are assumed not to form any subpopulation. Synaptic strengths between neurons within a subpopulation are assumed to be potentiated. By the numerical simulations, persistent firing of neurons in a subpopulation emerges; the persistent firing corresponds to the retention of memory as one of the functions of working memory. We find that the strength of external input and the strength of N-methyl- D-aspartate synapse are important factors for dynamical behaviors of the network; for example, if we enhance the strength of the external input to a subpopulation while the persistent firing is occurring in other subpopulation, the persistent firing occurs in the subpopulation or is sustained against the external input. These results reveal that the neural network as for the function of the working memory is controlled by the neuromodulation and the external stimuli within the proposed model. We also find that the persistent time of firing of the selective neurons shows a kind of phase transition as a function of the degree of potentiation of synapses.

  10. Voltage dependence of Hodgkin-Huxley rate functions for a multistage K+ channel voltage sensor within a membrane

    NASA Astrophysics Data System (ADS)

    Vaccaro, S. R.

    2014-11-01

    The activation of a K+channel sensor in two sequential stages during a voltage clamp may be described as the translocation of a Brownian particle in an energy landscape with two large barriers between states. A solution of the Smoluchowski equation for a square-well approximation to the potential function of the S4 voltage sensor satisfies a master equation and has two frequencies that may be determined from the forward and backward rate functions. When the higher-frequency terms have small amplitude, the solution reduces to the relaxation of a rate equation, where the derived two-state rate functions are dependent on the relative magnitude of the forward rates (α and γ ) and the backward rates (β and δ ) for each stage. In particular, the voltage dependence of the Hodgkin-Huxley rate functions for a K+channel may be derived by assuming that the rate functions of the first stage are large relative to those of the second stage—α ≫γ and β ≫δ . For a Shaker IR K+ channel, the first forward and backward transitions are rate limiting (α <γ and δ ≪β ), and for an activation process with either two or three stages, the derived two-state rate functions also have a voltage dependence that is of a similar form to that determined for the squid axon. The potential variation generated by the interaction between a two-stage K+ ion channel and a noninactivating Na+ ion channel is determined by the master equation for K+channel activation and the ionic current equation when the Na+channel activation time is small, and if β ≪δ and α ≪γ , the system may exhibit a small amplitude oscillation between spikes, or mixed-mode oscillation, in which the slow closed state modulates the K+ ion channel conductance in the membrane.

  11. Letters

    NASA Astrophysics Data System (ADS)

    1995-07-01

    Stoichiometry and Chemical Reactions by P. Radhakrishnamurty Author's Reply: Carlos Filgueiras Improving Laboratory Technique When Titrating Silver Ion with Ethylenediammine by Dean C. Luehrs Empirical Formulas by Alex R. Nisbet

  12. Letters

    NASA Astrophysics Data System (ADS)

    1999-04-01

    Winter's Entertainment by Terry L. Helser Ammonia-Air Mixtures Can Be Explosive by David Tudela Re: article by S. Toby The author replies Teaching Statistical Methods by Ken Muranaka Re: article by K. Thomasson, S. Lofthus-Merschman, M. Humbert, and N. Kulevsky The author K. A. Thomasson replies Properties of Zeolite A Obtained from Powdered Laundry Detergent by Pamela J. Davis, Herman van Bekkum, and Eric N. Coker Re: article by D. A. Lindquist and A. L. Smoot The author D. A. Lindquist replies Photon-Initiated Hydrogen-Chlorine Reaction by Richard W. Schwenz and Lynn Geiger Re: article by L. M. Egolf and J. T. Keiser (J. Chem. Educ. 1993, 70, A208) Precision and Accuracy in Measurements by Volker B. E. Thomsen Re: article by R. Treptow The author replies

  13. Letters

    NASA Astrophysics Data System (ADS)

    1998-12-01

    Beer's Law: The Real Hazards by S. R. Logan Re: article by M. A. Muyskens and E. T. Sevy The author replies Photodimerization of Maleic Anhydride by Zhijun Zhang Re: article by D. Todd and M. Pickering (J. Chem. Educ. 1988, 65, 1100) Qual from a Different Viewpoint by Francisco J. Arnáiz Re: article by M. Laing (J. Chem. Educ. 1993, 70, 666)

  14. Letters

    NASA Astrophysics Data System (ADS)

    2000-04-01

    Coulombic Models in Chemical Bonding by Lawrence J. Sacks and by Derek W. Smith Re: articles by R. J. Gillespie and by D. W. Smith D. W. Smith replies Capsaicin Hazard by Paul E. Vorndam Re: article by J. D. Batchelor and B. T. Jones B. T. Jones reply Editor's Note: Hazards Re: JCE 1999, 76, 240 and JCE 2000, 77, 266.

  15. Letters

    NASA Astrophysics Data System (ADS)

    1995-10-01

    Dimensions of Logarithmic Quantitites by Ian M. Mills Author's Reply: Philip Molyneux Reactions of Rare Earth Metals by G. L. Silver Undergraduate Polymer Experiment by Julian M. Dust Author's Reply: Kathryn R. Williams Other Publications on C6Cl6 and C2Cl6 by Richard L. Keiter Organic Hourglass Inclusions by James Benkn

  16. A lab-controlled simulation of a letter-speech sound binding deficit in dyslexia.

    PubMed

    Aravena, Sebastián; Snellings, Patrick; Tijms, Jurgen; van der Molen, Maurits W

    2013-08-01

    Dyslexic and non-dyslexic readers engaged in a short training aimed at learning eight basic letter-speech sound correspondences within an artificial orthography. We examined whether a letter-speech sound binding deficit is behaviorally detectable within the initial steps of learning a novel script. Both letter knowledge and word reading ability within the artificial script were assessed. An additional goal was to investigate the influence of instructional approach on the initial learning of letter-speech sound correspondences. We assigned children from both groups to one of three different training conditions: (a) explicit instruction, (b) implicit associative learning within a computer game environment, or (c) a combination of (a) and (b) in which explicit instruction is followed by implicit learning. Our results indicated that dyslexics were outperformed by the controls on a time-pressured binding task and a word reading task within the artificial orthography, providing empirical support for the view that a letter-speech sound binding deficit is a key factor in dyslexia. A combination of explicit instruction and implicit techniques proved to be a more powerful tool in the initial teaching of letter-sound correspondences than implicit training alone. PMID:23708733

  17. Born-Infeld/gravity correspondence

    NASA Astrophysics Data System (ADS)

    Grignani, Gianluca; Harmark, Troels; Marini, Andrea; Orselli, Marta

    2016-09-01

    In this paper we explore the correspondence between four-dimensional Born-Infeld theory and five-dimensional classical gravity. The Born-Infeld theory side corresponds to the low-energy effective theory for open strings ending on coincident D3-branes in a (slowly varying) background Kalb-Ramond field, including all higher-derivative corrections. On the gravity side one has the gravitational (closed-string) description of D3-branes in the same background Kalb-Ramond field and the correspondence is thus a consequence of the open/closed-string duality. According to the correspondence the gravity side provides a description of the strong coupling limit of Born-Infeld theory. This is a correspondence between effective theories in a similar sense as in the fluid/gravity correspondence. We match the Born-Infeld and gravity sides up to, and including, two-derivative corrections. To this end, we find a new gravity solution for D3-branes with flat embedding in the background of an arbitrary constant background Kalb-Ramond field and show that there are no two-derivative corrections to this for a slowly varying Kalb-Ramond field.

  18. Taming supersymmetric defects in 3d-3d correspondence

    NASA Astrophysics Data System (ADS)

    Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito

    2016-07-01

    We study knots in 3d Chern-Simons theory with complex gauge group {SL}(N,{{C}}), in the context of its relation with 3d { N }=2 theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d (2,0) theory, which is compactified on a 3-manifold \\hat{M}. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d {SL}(N,{{C}}) CS theory, in 3d { N }=2 theory, in 5d { N }=2 super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper [1], which contains more details and more results.

  19. [Protestant clergymen among Hahnemann's clientele. Patient histories in letters].

    PubMed

    Kreher, Simone; Schlott, Melanie; Schlott, Thilo

    2016-01-01

    As part of the research project, developments in the history of science and in the regional and ecclesiastic history of the late feudal petty state of Köthen-Anhalt have been assessed and numerous documents of the Nagel and Mühlenbein family histories examined that place the transcribed patient letters of the two Protestant clergymen within the context of the Hahnemann Archives. These findings complement and extend previous insights into Hahnemann's Köthen clientele, especially when it comes to the structure and milieu of the local clerical elite. Inspired by the interpretive methods of sequential textual analysis, form and content of the letters of the two clergymen and their relatives were also investigated as methodically structured lines of communication. The body of sources published here presents--embedded in the body-image (of sickness and health) prevalent at the time--the medical cultures of educated patients as well as the increasingly professionalized medical practices of Samuel Hahnemann in a flourishing urban doctor's surgery. The correspondence between the pastors Albert Wilhelm Gotthilf Nagel (1796-1835) and August Carl Ludwig Georg Mühlenbein (1797-1866), presented here in a standard edition, has been investigated at Fulda University as part of the project 'Homöopathisches Medicinieren zwischen alltäglicher Lebensführung und professioneller Praxis' ('Homeopathic medicine between everyday use and professional practice'). Of the altogether 78 transcribed documents, 53 are letters written by either of the two pastors, 16 are patient journals by Samuel Hahnemann, 9 letters by the pastors' wives and Mühlenbein's mother. The two series of letters, originally composed between 1831 and 1833 in old German cursive script, can now be used as sources for research into the history of homeopathy.

  20. [Protestant clergymen among Hahnemann's clientele. Patient histories in letters].

    PubMed

    Kreher, Simone; Schlott, Melanie; Schlott, Thilo

    2016-01-01

    As part of the research project, developments in the history of science and in the regional and ecclesiastic history of the late feudal petty state of Köthen-Anhalt have been assessed and numerous documents of the Nagel and Mühlenbein family histories examined that place the transcribed patient letters of the two Protestant clergymen within the context of the Hahnemann Archives. These findings complement and extend previous insights into Hahnemann's Köthen clientele, especially when it comes to the structure and milieu of the local clerical elite. Inspired by the interpretive methods of sequential textual analysis, form and content of the letters of the two clergymen and their relatives were also investigated as methodically structured lines of communication. The body of sources published here presents--embedded in the body-image (of sickness and health) prevalent at the time--the medical cultures of educated patients as well as the increasingly professionalized medical practices of Samuel Hahnemann in a flourishing urban doctor's surgery. The correspondence between the pastors Albert Wilhelm Gotthilf Nagel (1796-1835) and August Carl Ludwig Georg Mühlenbein (1797-1866), presented here in a standard edition, has been investigated at Fulda University as part of the project 'Homöopathisches Medicinieren zwischen alltäglicher Lebensführung und professioneller Praxis' ('Homeopathic medicine between everyday use and professional practice'). Of the altogether 78 transcribed documents, 53 are letters written by either of the two pastors, 16 are patient journals by Samuel Hahnemann, 9 letters by the pastors' wives and Mühlenbein's mother. The two series of letters, originally composed between 1831 and 1833 in old German cursive script, can now be used as sources for research into the history of homeopathy. PMID:27263219

  1. Crowding affects letters and symbols differently.

    PubMed

    Grainger, Jonathan; Tydgat, Ilse; Isselé, Joanna

    2010-06-01

    Five experiments examined crowding effects with letter and symbol stimuli. Experiments 1 through 3 compared 2-alternative forced-choice (2AFC) identification accuracy for isolated targets presented left and right of fixation with targets flanked either by 2 other items of the same category or a single item situated to the right or left of targets. Interference from flankers (crowding) was significantly stronger for symbols than letters. Single flankers generated performance similar to the isolated targets when the stimuli were letters but closer to the 2-flanker condition when the stimuli were symbols. Experiment 4 confirmed this pattern using a partial-report bar probe procedure. Experiment 5 showed that another measure of crowding, critical spacing, was greater for symbols than for letters. The results support the hypothesis that letter-string processing involves a specialized system developed to limit the spatial extent of crowding for letters in words.

  2. How automatic are crossmodal correspondences?

    PubMed

    Spence, Charles; Deroy, Ophelia

    2013-03-01

    The last couple of years have seen a rapid growth of interest (especially amongst cognitive psychologists, cognitive neuroscientists, and developmental researchers) in the study of crossmodal correspondences - the tendency for our brains (not to mention the brains of other species) to preferentially associate certain features or dimensions of stimuli across the senses. By now, robust empirical evidence supports the existence of numerous crossmodal correspondences, affecting people's performance across a wide range of psychological tasks - in everything from the redundant target effect paradigm through to studies of the Implicit Association Test, and from speeded discrimination/classification tasks through to unspeeded spatial localisation and temporal order judgment tasks. However, one question that has yet to receive a satisfactory answer is whether crossmodal correspondences automatically affect people's performance (in all, or at least in a subset of tasks), as opposed to reflecting more of a strategic, or top-down, phenomenon. Here, we review the latest research on the topic of crossmodal correspondences to have addressed this issue. We argue that answering the question will require researchers to be more precise in terms of defining what exactly automaticity entails. Furthermore, one's answer to the automaticity question may also hinge on the answer to a second question: Namely, whether crossmodal correspondences are all 'of a kind', or whether instead there may be several different kinds of crossmodal mapping (e.g., statistical, structural, and semantic). Different answers to the automaticity question may then be revealed depending on the type of correspondence under consideration. We make a number of suggestions for future research that might help to determine just how automatic crossmodal correspondences really are. PMID:23370382

  3. On Becoming a Doctor of Humane Letters.

    PubMed

    Tribble Md, Curt

    2016-01-01

    In an era of rapid, cheap, and efficient electronic communication, the practice-and art-of letter writing has faded. There are many reasons for us as physicians and surgeons to resist this evolution. And, there are many opportunities to employ letter writing to the benefit of ourselves, our patients, and our colleagues. A true Doctor of Humane Letters is an honorary degree, generally awarded for significant contributions to society.  However, given that humane can be defined as showing compassion, understanding, mercy, and tolerance, we can all strive to be worthy of such a distinction. There are many mundane letters familiar to us all, such as letters of recommendation, letters of thanks, and letters of commendation. However, I would like to offer some suggestions about other less common, but useful, types of letters that might prove valuable to physicians both in training and in practice. These include letters of inquiry, condolence, reflection, and explanation, as well as some notes about missives that are often best written but not sent. PMID:27585190

  4. Resource Letter: GW-1: Global warming

    NASA Astrophysics Data System (ADS)

    Firor, John W.

    1994-06-01

    This Resource Letter provides a guide to the literature on the possibility of a human-induced climate change—a global warming. Journal articles and books are cited for the following topics: the Greenhouse Effect, sources of infrared-trapping gases, climate models and their uncertainties, verification of climate models, past climate changes, and economics, ethics, and politics of policy responses to climate change. [The letter E after an item indicates elementary level or material of general interest to persons becoming informed in the field. The letter I, for intermediate level, indicates material of somewhat more specialized nature, and the letter A indicates rather specialized or advanced material.

  5. [The professor and his student. The correspondence between Lorenz Heister and Christoph Jacob Trew].

    PubMed

    Ruisinger, Marion Maria; Schnalke, Thomas

    2004-01-01

    Letters were the central medium of communication in the medical scientific community of the 18th century. Professional as well as personal relationships were established among the various correspondents. These relationships constituted the smallest units of communication which contributed to the regional and international scientific network of the Republic of Letters. A correspondence that grew out of a trusted teacher-student relationship could gain an especially intense character both intellectually and personally. This contribution offers an analysis of an example of just such a correspondence. Lorenz Heister (1683--1758), medical professor at the universities of Altdorf and Helmstedt, and his disciple, Christoph Jacob Trew (1695--1769), who became a renowned physician and natural scientist in Nuremberg, communicated in letters to one another over a span of almost forty years. Their correspondence started as a rather asymmetrical dialogue. Over time, however, Heister and Trew came to meet as equals in almost every field of their competence. Their letters reveal a broad spectrum of scientific, organisational, professional, medical and personal issues which formed the basis of a stable and lasting learned correspondence in the age of Enlightenment.

  6. Quantum Painleve-Calogero correspondence

    SciTech Connect

    Zabrodin, A.; Zotov, A.

    2012-07-15

    The Painleve-Calogero correspondence is extended to auxiliary linear problems associated with Painleve equations. The linear problems are represented in a new form which has a suggestive interpretation as a 'quantized' version of the Painleve-Calogero correspondence. Namely, the linear problem responsible for the time evolution is brought into the form of non-stationary Schroedinger equation in imaginary time, {partial_derivative}{sub t}{psi}=((1/2) {partial_derivative}{sub x}{sup 2}+V(x,t)){psi}, whose Hamiltonian is a natural quantization of the classical Calogero-like Hamiltonian H=(1/2) p{sup 2}+V(x,t) for the corresponding Painleve equation. In present paper, we present explicit constructions for the first five equations from the Painleve list.

  7. Letter to the Editor on Robert Yaes's Letter

    NASA Technical Reports Server (NTRS)

    Krisher, T. P.

    1993-01-01

    In his letter on page 13 of the March 1993 issue, Robert Yaes raised the question of whether the existence of the cosmic microwave background (CMB), now observed so precisely with COBE, is compatible with the principle of relativity: The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or other of two systems of coordinates in uniform translatory motion. Although I do not claim to provide an xpertresponse to this question, as desired by Yaes, it is my understanding that the principle of relativity is not necessarily violated by the mere existence of a universal reference frame. The laws of physics can still be invariant under some transformation of coordinates. This transformation is not specified by the principle of relativity itself, although we have discovered so far that Nature respects Lorentz invariance (principle of the constancy of the velocity of light).

  8. The influence of reading expertise in mirror-letter perception: Evidence from beginning and expert readers

    PubMed Central

    Duñabeitia, Jon Andoni; Dimitropoulou, María; Estévez, Adelina; Carreiras, Manuel

    2013-01-01

    The visual word recognition system recruits neuronal systems originally developed for object perception which are characterized by orientation insensitivity to mirror reversals. It has been proposed that during reading acquisition beginning readers have to “unlearn” this natural tolerance to mirror reversals in order to efficiently discriminate letters and words. Therefore, it is supposed that this unlearning process takes place in a gradual way and that reading expertise modulates mirror-letter discrimination. However, to date no supporting evidence for this has been obtained. We present data from an eye-movement study that investigated the degree of sensitivity to mirror-letters in a group of beginning readers and a group of expert readers. Participants had to decide which of the two strings presented on a screen corresponded to an auditorily presented word. Visual displays always included the correct target word and one distractor word. Results showed that those distractors that were the same as the target word except for the mirror lateralization of two internal letters attracted participants’ attention more than distractors created by replacement of two internal letters. Interestingly, the time course of the effects was found to be different for the two groups, with beginning readers showing a greater tolerance (decreased sensitivity) to mirror-letters than expert readers. Implications of these findings are discussed within the framework of preceding evidence showing how reading expertise modulates letter identification. PMID:24273596

  9. The influence of reading expertise in mirror-letter perception: Evidence from beginning and expert readers.

    PubMed

    Duñabeitia, Jon Andoni; Dimitropoulou, María; Estévez, Adelina; Carreiras, Manuel

    2013-06-01

    The visual word recognition system recruits neuronal systems originally developed for object perception which are characterized by orientation insensitivity to mirror reversals. It has been proposed that during reading acquisition beginning readers have to "unlearn" this natural tolerance to mirror reversals in order to efficiently discriminate letters and words. Therefore, it is supposed that this unlearning process takes place in a gradual way and that reading expertise modulates mirror-letter discrimination. However, to date no supporting evidence for this has been obtained. We present data from an eye-movement study that investigated the degree of sensitivity to mirror-letters in a group of beginning readers and a group of expert readers. Participants had to decide which of the two strings presented on a screen corresponded to an auditorily presented word. Visual displays always included the correct target word and one distractor word. Results showed that those distractors that were the same as the target word except for the mirror lateralization of two internal letters attracted participants' attention more than distractors created by replacement of two internal letters. Interestingly, the time course of the effects was found to be different for the two groups, with beginning readers showing a greater tolerance (decreased sensitivity) to mirror-letters than expert readers. Implications of these findings are discussed within the framework of preceding evidence showing how reading expertise modulates letter identification.

  10. Effect of Orthographic Processes on Letter Identity and Letter-Position Encoding in Dyslexic Children

    PubMed Central

    Reilhac, Caroline; Jucla, Mélanie; Iannuzzi, Stéphanie; Valdois, Sylviane; Démonet, Jean-François

    2012-01-01

    The ability to identify letters and encode their position is a crucial step of the word recognition process. However and despite their word identification problem, the ability of dyslexic children to encode letter identity and letter-position within strings was not systematically investigated. This study aimed at filling this gap and further explored how letter identity and letter-position encoding is modulated by letter context in developmental dyslexia. For this purpose, a letter-string comparison task was administered to French dyslexic children and two chronological age (CA) and reading age (RA)-matched control groups. Children had to judge whether two successively and briefly presented four-letter strings were identical or different. Letter-position and letter identity were manipulated through the transposition (e.g., RTGM vs. RMGT) or substitution of two letters (e.g., TSHF vs. TGHD). Non-words, pseudo-words, and words were used as stimuli to investigate sub-lexical and lexical effects on letter encoding. Dyslexic children showed both substitution and transposition detection problems relative to CA-controls. A substitution advantage over transpositions was only found for words in dyslexic children whereas it extended to pseudo-words in RA-controls and to all type of items in CA-controls. Letters were better identified in the dyslexic group when belonging to orthographically familiar strings. Letter-position encoding was very impaired in dyslexic children who did not show any word context effect in contrast to CA-controls. Overall, the current findings point to a strong letter identity and letter-position encoding disorder in developmental dyslexia. PMID:22661961

  11. National Security Management Correspondence Course.

    ERIC Educational Resources Information Center

    Industrial Coll. of the Armed Forces (DOD), Washington, DC.

    A course of study on the fundamental aspects of the areas of knowledge which are essential to effective management of national security is presented. The course presents the substance of the Industrial College resident curriculum adapted to the correspondence method of study. The subject matter is designed to impart knowledge and understanding of…

  12. The Traps of Formal Correspondence.

    ERIC Educational Resources Information Center

    Albert, Sandor

    The dangers of translation are discussed when the translator does not try to create textual equivalence, but settles for formal correspondence (i.e., with simple transcoding at a linguistic level) during the process of translating. Difficulties of explaining, commenting, or summarizing rather than translating are also discussed. Pedagogical and…

  13. Letter Names and Phonological Awareness Help Children to Learn Letter-Sound Relations

    ERIC Educational Resources Information Center

    Cardoso-Martins, Claudia; Mesquita, Tereza Cristina Lara; Ehri, Linnea

    2011-01-01

    Two experimental training studies with Portuguese-speaking preschoolers in Brazil were conducted to investigate whether children benefit from letter name knowledge and phonological awareness in learning letter-sound relations. In Experiment 1, two groups of children were compared. The experimental group was taught the names of letters whose sounds…

  14. Letters from the Future: Suggestions for Using Letter Writing as a School Counselling Intervention

    ERIC Educational Resources Information Center

    Kress, Victoria E.; Hinkle, Michelle Gimenez; Protivnak, Jake J.

    2011-01-01

    This article presents a school counselling intervention that utilises letters written from the future. Few peer-reviewed articles have addressed the use of letter writing in a school counselling context, and none have focused on the use of letters from the future as a means of school counsellor intervention. The authors present a theoretical…

  15. Letter Names: Effect on Letter Saying, Spelling, and Word Recognition in Hebrew.

    ERIC Educational Resources Information Center

    Levin, Iris; Patel, Sigal; Margalit, Tamar; Barad, Noa

    2002-01-01

    Examined whether letter names, which bridge the gap between oral and written language among English speaking children, have a similar function in Hebrew. In findings from studies of Israeli kindergartners and first graders, children were found to rely on letter names in performing a number of letter saying, spelling, and word recognition tasks.…

  16. Letter-Name Letter-Sound and Phonological Awareness: Evidence from Greek-Speaking Kindergarten Children

    ERIC Educational Resources Information Center

    Manolitsis, George; Tafa, Eufimia

    2011-01-01

    The purpose of this study was to examine longitudinally the development of letter-sound and letter-name knowledge and their relation to each other and to various aspects of phonological awareness in a sample of Greek kindergarten children who did not know how to read. One hundred twenty children aged 58-69 months were assessed on letter-sound and…

  17. Attitudes to abortion in the era of reform: evidence from the Abortion Law Reform Association correspondence.

    PubMed

    Jones, Emma L

    2011-01-01

    This article examines letters sent by members of the general public to the Abortion Law Reform Association (ALRA) in the decade immediately before the 1967 Abortion Act. It shows how a voluntary organisation, in their aim of supporting a specific cause of unclear legality, called forth correspondence from those in need. In detailing the personal predicaments of those facing an unwanted pregnancy, this body of correspondence was readily deployed by ALRA in their efforts to mobilise support for abortion law reform, thus exercising a political function. A close examination of the content of the letters and the epistolary strategies adopted by their writers reveals that as much as they were a lobbying tool for changes in abortion law, these letters were discursively shaped by debates surrounding that very reform.

  18. Osler and the Infected Letter

    PubMed Central

    2005-01-01

    The spread of infectious agents through the mail has concerned public health officials for 5 centuries. The dissemination of anthrax spores in the US mail in 2001 was a recent example. In 1901, two medical journals reported outbreaks of smallpox presumably introduced by letters contaminated with variola viruses. The stability and infectivity of the smallpox virus are reviewed from both a historical (anecdotal) perspective and modern virologic studies. Bubonic plague was the contagious disease that led to quarantines as early as the 14th century in port cities in southern Europe. Later, smallpox, cholera, typhus, and yellow fever were recognized as also warranting quarantine measures. Initially, attempts were made to decontaminate all goods imported from pestilential areas, particularly mail. Disinfection of mail was largely abandoned in the early 20th century with newer knowledge about the spread and stability of these 5 infectious agents. PMID:15890120

  19. From Numbers to Letters: Feedback Regularization in Visual Word Recognition

    ERIC Educational Resources Information Center

    Molinaro, Nicola; Dunabeitia, Jon Andoni; Marin-Gutierrez, Alejandro; Carreiras, Manuel

    2010-01-01

    Word reading in alphabetic languages involves letter identification, independently of the format in which these letters are written. This process of letter "regularization" is sensitive to word context, leading to the recognition of a word even when numbers that resemble letters are inserted among other real letters (e.g., M4TERI4L). The present…

  20. 76 FR 37094 - List of Correspondence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ... May Be of Interest to Readers Topic Addressed: Harassment And Bullying. Dear Colleague Letter dated October 26, 2010 from Office for Civil Rights Assistant Secretary Russlynn Ali, regarding bullying...

  1. 48 CFR 1516.603 - Letter Contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Letter Contracts. 1516.603 Section 1516.603 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Time-and-Materials, Labor-Hour, and Letter Contracts...

  2. 24 CFR 241.1010 - Feasibility letter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Feasibility letter. 241.1010 Section 241.1010 Housing and Urban Development Regulations Relating to Housing and Urban Development...-Eligibility Requirements § 241.1010 Feasibility letter. (a) Request for study. The owner may request...

  3. Open letter to Minister Helen Morton.

    PubMed

    Campbell, Emma; Oke, Lin; Cairney, Joanne; Fergusson, Fiona; Booth, Jodie; Taylor, Karen; Baird, Tyson; Sheppard, Loretta; Jensen, Heather; Kao, Kevin

    2015-10-01

    This letter was sent to the Honourable Helen Morton by Emma Campbell after the Occupational Therapy Australia National Conference. A number of members of First Australian and Australian OTs online were keen to show their support for Emma's letter and share this with other OT colleagues. PMID:26726327

  4. Letter to Editor - "Reply to RP Heaney"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A letter to the editor was submitted in reply to a letter written to the editor of the American Journal of Clinical Nutrition regarding a recent publication (Hunt, CD. and Johnson, LK. Calcium requirements: new estimations for men and women by cross-sectional statistical analyses of calcium balance...

  5. Letter to, and Paintings by, George Catlin

    ERIC Educational Resources Information Center

    Rosenbaum, David; Potter, Lee Ann; Eder, Elizabeth K.

    2008-01-01

    Letters received and sent by Secretary of War Lewis Cass in the 1830s reveal much about relations between the U.S. government and Native Americans. In the immediate aftermath of the Indian Removal Act, signed into law on May 28, 1830, by President Andrew Jackson, some letters came from interpreters and school teachers seeking payment for their…

  6. When Do First Letters Mnemonics Aid Recall?

    ERIC Educational Resources Information Center

    Morris, P. E.; Cook, N.

    1978-01-01

    The evidence for the effectiveness of the first letter mnemonic technique is confused. There are at least three studies showing no effect, and one where an improvement in recall occurred. Reports two experiments which attempted to locate the conditions under which the first letter mnemonic is effective. (Author/RK)

  7. Letters in Time and Retinotopic Space

    ERIC Educational Resources Information Center

    Adelman, James S.

    2011-01-01

    Various phenomena in tachistoscopic word identification and priming (WRODS and LTRS are confused with and prime WORDS and LETTERS) suggest that position-specific channels are not used in the processing of letters in words. Previous approaches to this issue have sought alternative matching rules because they have assumed that these phenomena reveal…

  8. 7 CFR 1773.33 - Management letter.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... than as allowed under 7 CFR part 1744, subpart E; (ii) The requirement for a borrower to prepare and... 7 Agriculture 12 2014-01-01 2013-01-01 true Management letter. 1773.33 Section 1773.33 Agriculture... (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Reporting Requirements § 1773.33 Management letter. The...

  9. Linguistic Prescriptivism in Letters to the Editor

    ERIC Educational Resources Information Center

    Lukac, Morana

    2016-01-01

    The public's concern with the fate of the standard language has been well documented in the history of the complaint tradition. The print media have for centuries featured letters to the editor on questions of language use. This study examines a corpus of 258 language-related letters to the editor published in the English-speaking print media. By…

  10. 48 CFR 18.112 - Letter contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Letter contracts. 18.112 Section 18.112 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.112 Letter...

  11. 48 CFR 18.112 - Letter contracts.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Letter contracts. 18.112 Section 18.112 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.112 Letter...

  12. 48 CFR 18.112 - Letter contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Letter contracts. 18.112 Section 18.112 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.112 Letter...

  13. 48 CFR 18.112 - Letter contracts.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Letter contracts. 18.112 Section 18.112 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.112 Letter...

  14. 48 CFR 18.112 - Letter contracts.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Letter contracts. 18.112 Section 18.112 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION CONTRACTING METHODS AND CONTRACT TYPES EMERGENCY ACQUISITIONS Available Acquisition Flexibilities 18.112 Letter...

  15. Genre Analysis of Business Letters of Negotiation.

    ERIC Educational Resources Information Center

    dos Santos, V. B. M. Pinto

    2002-01-01

    Reports findings of a survey on genre analysis of 117 commercial letters in English exchanged by fax between a Brazilian company and two European companies. The letters were analyzed in terms of shared communicative purposes and rhetorical features that together contribute to the building-up of the resulting generic structure named "Business…

  16. Writing Back and Forth: Class Letters.

    ERIC Educational Resources Information Center

    Fulwiler, Toby

    1997-01-01

    Recommends that college teachers and their students exchange weekly letters, in either paper or electronic form, as a familiar and friendly means of communication. The method increases dialog, suggests rethinking, and encourages rewriting while keeping the stakes low. Students respond well to the assignment. Samples of student letters and comments…

  17. Cognitive Determinants of Early Letter Knowledge

    ERIC Educational Resources Information Center

    Helal, Suha; Weil-Barais, Annick

    2015-01-01

    The present study investigated the general cognitive determinants of alphabetic letter knowledge. It involved 60 French kindergarten children (mean age: five years six months). Two test batteries were used: the CMS to evaluate general cognitive abilities (memory, attention, and learning), and the LKT to assess letter knowledge and its various…

  18. Statistical Learning, Letter Reversals, and Reading

    ERIC Educational Resources Information Center

    Treiman, Rebecca; Gordon, Jessica; Boada, Richard; Peterson, Robin L.; Pennington, Bruce F.

    2014-01-01

    Reversal errors play a prominent role in theories of reading disability. We examined reversal errors in the writing of letters by 5- to 6-year-old children. Of the 130 children, 92 had a history of difficulty in producing speech sounds, a risk factor for reading problems. Children were more likely to reverse letter forms that face left, such as…

  19. 46 CFR 170.120 - Stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Stability letter. 170.120 Section 170.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Stability Instructions for Operating Personnel § 170.120 Stability letter....

  20. 46 CFR 170.120 - Stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Stability letter. 170.120 Section 170.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Stability Instructions for Operating Personnel § 170.120 Stability letter....

  1. 46 CFR 170.120 - Stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Stability letter. 170.120 Section 170.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Stability Instructions for Operating Personnel § 170.120 Stability letter....

  2. 46 CFR 170.120 - Stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Stability letter. 170.120 Section 170.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Stability Instructions for Operating Personnel § 170.120 Stability letter....

  3. 46 CFR 170.120 - Stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Stability letter. 170.120 Section 170.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Stability Instructions for Operating Personnel § 170.120 Stability letter....

  4. Transmittal Letters: Communicating the Financial Picture.

    ERIC Educational Resources Information Center

    Piotrowski, Craig L.

    1987-01-01

    The transmittal letter, part of a school district's comprehensive annual financial report, provides a creative opportunity to communicate the financial picture of a district to readers. After the introduction, the letter should include sections on (1) mission, services, and environment; (2) financial highlights; (3) systems and controls; and (4)…

  5. An Open Letter to Tomorrow's Secondary Teachers

    ERIC Educational Resources Information Center

    Worthy, Jeff

    2016-01-01

    The article takes the form of a letter written to pre-service or beginning teachers at the secondary level in the public school system. The letter acknowledges the attributes they bring to the profession (enthusiasm, optimism, creativity, and open-mindedness) and calls on them to make the most of and work to sustain these traits as they begin…

  6. An Open Letter to Premier Wen Jiabao

    ERIC Educational Resources Information Center

    Chinese Education and Society, 2008

    2008-01-01

    This article is an open letter of a group of early childhood education (ECE) practitioners to Premier Wen Jiabao. This open letter was written with one goal in mind: to ask Premier Wen's government to take measures to protect young children and support early childhood education. These practitioners have become worried about the many accidents that…

  7. Evolutionary theory in letters to the editor.

    PubMed

    Silva, Eric Orion; Lowe, Clayton Cory

    2015-05-01

    This research note presents the results of a content analysis of 234 letters to the editors that discuss evolutionary theory and were published in American newspapers. We find that letters to the editor both support and hinder the cause of teaching evolutionary theory in American secondary schools. On the one hand, anti-evolutionary theory messages are marginalized in the letters section. This marginalization signals a low level of legitimacy for creationism. It might also contribute to the sense of tension that sustains creationist identities. On the other hand, relatively few letters explicitly note the fact that scientists or the scientific community accept evolution. Interestingly, the obscuration of the scientific community's support for evolutionary theory occurs both in letters supporting and opposing evolutionary theory.

  8. Evolutionary theory in letters to the editor.

    PubMed

    Silva, Eric Orion; Lowe, Clayton Cory

    2015-05-01

    This research note presents the results of a content analysis of 234 letters to the editors that discuss evolutionary theory and were published in American newspapers. We find that letters to the editor both support and hinder the cause of teaching evolutionary theory in American secondary schools. On the one hand, anti-evolutionary theory messages are marginalized in the letters section. This marginalization signals a low level of legitimacy for creationism. It might also contribute to the sense of tension that sustains creationist identities. On the other hand, relatively few letters explicitly note the fact that scientists or the scientific community accept evolution. Interestingly, the obscuration of the scientific community's support for evolutionary theory occurs both in letters supporting and opposing evolutionary theory. PMID:25540333

  9. Letter perception: from pixels to pandemonium.

    PubMed

    Grainger, Jonathan; Rey, Arnaud; Dufau, Stéphane

    2008-10-01

    In 1959, Oliver Selfridge proposed a model of letter perception, the Pandemonium model, in which the central hypothesis was that letters are identified via their component features. Although a consensus developed around this general approach over the years, key evidence in its favor remained lacking. Recent research has started to provide important evidence in favor of feature-based letter perception, describing the nature of the features, and the time-course of processes involved in mapping features onto abstract letter identities. There is now hope that future 'pandemonium-like' models will be able to account for the rich empirical database on letter identification that has accumulated over the past 50 years, hence solving one key component of the reading process.

  10. Resource Letter SE-2: Solar Energy

    NASA Astrophysics Data System (ADS)

    Hodges, Laurent

    1982-10-01

    This resource letter provides a source of information about the main types of solar energy and their uses, updating Resource Letter SE-1 issued seven years ago. It is intended for the use of high school and college teachers both in developing courses and in guiding students to the literature of solar energy applications. Articles marked with an asterisk have been selected for publication in an accompanying reprint book. The letter E after the reference number denotes a relatively elementary item, useful for high school and introductory college use and the educated public; the letter I denotes intermediate level references, sophomore to senior level; and the letter A denotes advanced material, principally for senior and graduate-level courses.

  11. The challenges of editorship: a reflection on editing the Jung-Neumann correspondence.

    PubMed

    Liebscher, Martin

    2016-04-01

    The complete correspondence between C.G. Jung and Erich Neumann was published in 2015. This article attempts to provide insight into the practical task, as well as the theoretical background, of the editing process. The advantages and possibilities of an unabridged edition with an extensive historical contextualization are demonstrated, and compared to the approach of the editors of the Jung Letters and their selection therein of Jung's letters to Neumann. The practical points under consideration include the establishment of the letter corpus, the ascertainment of dates and the chronological arrangement of the letter exchange, as well as the deciphering of handwritten letters. Theoretical aspects under discussion involve the question of the merits of a critical contextualisation and the position of the editor vis-à-vis the research object. The example of the selecting and editing of Jung's letters to Neumann by Aniela Jaffé and Gerhard Adler reveals how drastically the close ties of those editors with Jung, Neumann, and members of the Zurich analytical circles compromised their editorial work at times. The advantage for an editor being able to work from an historical distance is appreciated. PMID:27000692

  12. The challenges of editorship: a reflection on editing the Jung-Neumann correspondence.

    PubMed

    Liebscher, Martin

    2016-04-01

    The complete correspondence between C.G. Jung and Erich Neumann was published in 2015. This article attempts to provide insight into the practical task, as well as the theoretical background, of the editing process. The advantages and possibilities of an unabridged edition with an extensive historical contextualization are demonstrated, and compared to the approach of the editors of the Jung Letters and their selection therein of Jung's letters to Neumann. The practical points under consideration include the establishment of the letter corpus, the ascertainment of dates and the chronological arrangement of the letter exchange, as well as the deciphering of handwritten letters. Theoretical aspects under discussion involve the question of the merits of a critical contextualisation and the position of the editor vis-à-vis the research object. The example of the selecting and editing of Jung's letters to Neumann by Aniela Jaffé and Gerhard Adler reveals how drastically the close ties of those editors with Jung, Neumann, and members of the Zurich analytical circles compromised their editorial work at times. The advantage for an editor being able to work from an historical distance is appreciated.

  13. A Calendar of the Correspondence of Sir John Herschel

    NASA Astrophysics Data System (ADS)

    Crowe, Michael J.; Dyck, David R.; Kevin, James R.

    This volume provides for the first time summaries, descriptions, and documentation for 14,815 letters written by or sent to Sir John Herschel (1792-1871). Herschel's numerous contributions to astronomy as well as to mathematics, physics, chemistry (especially photochemistry and photography), meteorology, philosophy of science, and scientific organization, led his British contemporaries to regard him as the most prominent scientist of his era. Because Herschel corresponded on a remarkable array of topics and with leading figures both in Britain and beyond, this volume gives scholars access to a wealth of revealing new information. The many new uses of the volume are enhanced by its Biographical Register, which indentifies about 1500 of Herschel's correspondents, and its Index, which supplies 30,000 references. This volume is far and away the most extensive source of information on John Herschel ever published. Also included are bibliographies of Herschel's publications and of publications on him.

  14. Letters from Ainsworth: Contesting the ‘Organization’ of Attachment

    PubMed Central

    Landa, Sophie; Duschinsky, Robbie

    2013-01-01

    As Main (1999) noted in her obituary for Mary Ainsworth, ‘she was interacting weekly by letter and manuscript with her mentor and friend, John Bowlby, and their academic correspondence formed an important part of her, and implicitly our, life.’ These letters of Ainsworth to John Bowlby during the 1980s, available in the Wellcome Trust Library in London, contain valuable reflections on the work of her pupils to extend her system of classifying infant behaviour in the Strange Situation Procedure. Mary Main proposed a D classification and interpreted such behaviour as a breakdown in an ABC strategy caused by a conflict between a disposition to approach and flee from the caregiver. Patricia Crittenden extended the subtypes of A and C, using a developmental model of information processing, and observed that they could be used together in A/C combinations. These letters offer insight into Ainsworth’s intellectual rationale for encouraging both Main and Crittenden in their conflicting endeavours. PMID:23667365

  15. Claim and Adjustment Letters: Theory Versus Practice and Legal Implications.

    ERIC Educational Resources Information Center

    Aalberts, Roberts J.; Krajewski, Lorraine A.

    1987-01-01

    Addresses the reasons companies respond to consumer complaints, analyzes 35 business letters responding to complaints and the ways in which the letters deviate from textbook recommendations, and examines legal theories applicable to claim adjustment letters. (JC)

  16. What letters can "learn" from Arabic digits--fMRI-controlled single case therapy study of peripheral agraphia.

    PubMed

    Jung, Stefanie; Halm, Katja; Huber, Walter; Willmes, Klaus; Klein, Elise

    2015-10-01

    Research on (hand-)writing has revealed that Exner's area subserves transferring linguistic impulses into writing programmes. We report on a patient with a lesion affecting Broca's and Exner's area suffering from severe peripheral agraphia for letters but not for Arabic digits. Analogous to semantic (magnitude) information in numbers, we developed a specifically tailored writing training: additional mental imagery based semantic information was attached to letters. The training resulted in significant improvements. Imaging data revealed stronger fronto-parietal network activity including perilesional activation around Exner's area and precuneus for writing letters to dictation than for writing letters corresponding to their mental image expressions. Follow-up testing showed not only stable training effects but also an activation shift into the left angular gyrus. Results document neuronal correlates of a successful intervention by attaching additional meanings to letters in order to retrieve their grapho-motor patterns. These findings contribute to understanding the impact of Exner's area. PMID:26186229

  17. Statistical mechanics of letters in words

    PubMed Central

    Stephens, Greg J.; Bialek, William

    2013-01-01

    We consider words as a network of interacting letters, and approximate the probability distribution of states taken on by this network. Despite the intuition that the rules of English spelling are highly combinatorial and arbitrary, we find that maximum entropy models consistent with pairwise correlations among letters provide a surprisingly good approximation to the full statistics of words, capturing ~92% of the multi-information in four-letter words and even “discovering” words that were not represented in the data. These maximum entropy models incorporate letter interactions through a set of pairwise potentials and thus define an energy landscape on the space of possible words. Guided by the large letter redundancy we seek a lower-dimensional encoding of the letter distribution and show that distinctions between local minima in the landscape account for ~68% of the four-letter entropy. We suggest that these states provide an effective vocabulary which is matched to the frequency of word use and much smaller than the full lexicon. PMID:20866490

  18. 15 CFR 908.13 - Address of letters.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... SUBMITTING REPORTS ON WEATHER MODIFICATION ACTIVITIES § 908.13 Address of letters. Letters and other communications intended for the Administrator, in connection with weather modification reporting or...

  19. 15 CFR 908.13 - Address of letters.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... SUBMITTING REPORTS ON WEATHER MODIFICATION ACTIVITIES § 908.13 Address of letters. Letters and other communications intended for the Administrator, in connection with weather modification reporting or...

  20. 48 CFR 871.201-4 - Letter contracts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SUPPLEMENTARY REGULATIONS LOAN GUARANTY AND VOCATIONAL REHABILITATION AND EMPLOYMENT PROGRAMS Vocational Rehabilitation and Employment Service 871.201-4 Letter contracts. Letter contracts are authorized for use...

  1. 48 CFR 871.201-4 - Letter contracts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... SUPPLEMENTARY REGULATIONS LOAN GUARANTY AND VOCATIONAL REHABILITATION AND EMPLOYMENT PROGRAMS Vocational Rehabilitation and Employment Service 871.201-4 Letter contracts. Letter contracts are authorized for use...

  2. EDITORIAL: Letter from the Editor Letter from the Editor

    NASA Astrophysics Data System (ADS)

    Pashinin, Pavel P.

    2013-01-01

    Dear readers, contributors, and members of the world laser physics community. It is a great honour for us to introduce to you our new publishing partner, IOP Publishing, a subsidiary of the Institute of Physics, United Kingdom. IOP Publishing is a world renowned authority in producing journals, magazines, websites and services that enable researchers and research organizations to present their work to a world-wide audience. Laser Physics, the first English-language scientific journal in Russia, was founded in 1990 on the initiative of Alexander M Prokhorov, a pioneer and leader in laser physics research. Professor Prokhorov served as the first Editor-in-Chief of the journal until 2002. We are proud that it is our 23rd year of publishing Laser Physics and our 10th year of publishing Laser Physics Letters. We would like to honour the memory of our friend, late Professor Igor Yevseyev, whose enthusiasm and unwavering dedication to our journals contributed most significantly to their success. It was initially his idea in 2011 to approach IOP with a partnership proposal. We deeply regret that he is no longer with us as we enter this productive alliance. Now, in partnership with IOP, we are turning a new page in providing world-wide access to the cutting-edge research results in our journals, serving our well established global audience. We see new horizons opening for our journals for years to come and hope that our readers share our enthusiasm and aspirations. Please accept our best wishes for all your new scientific endeavors in the exciting field of laser physics.

  3. The Kepler - Mästlin correspondence. (German Title: Der Briefwechsel zwischen Kepler und Mästlin)

    NASA Astrophysics Data System (ADS)

    Seck, Friedrich

    The correspondence between Kepler and Mästlin covers the period from 1594 to 1620. It is interrupted by year-long pauses and ends a full 10 years before Kepler's death. Initially, Mästlin is quite open to Kepler's new ideas (Mysterium Cosmographicum), but later he showed little understanding for the revolutionary innovations of the mature Kepler. Kepler's insistent wishes and the unfounded fear that Kepler might publish his letters gave rise to long periods of silence. Some passages in letters of his associates suggest that Mästlin suffered from melancholy (in today's terms: depression) induced by age.

  4. Magnetized Kerr/CFT correspondence

    NASA Astrophysics Data System (ADS)

    Siahaan, Haryanto M.

    2016-08-01

    We extend the conjectured Kerr/CFT correspondence to the case of extremal Kerr black holes immersed by a magnetic field, namely the extremal Melvin–Kerr black holes. We compute the central charge which appears in the associated Virasoro algebra generated by a class of diffeomorphisms that satisfies a set of boundary conditions in the near horizon of an extremal Melvin–Kerr black hole. Our results support the Kerr/CFT conjecture, where the macroscopic Bekenstein–Hawking entropy for an extremal Melvin–Kerr black hole matches the result obtained from a dual 2D CFT microscopic computation using Cardy formula. Interestingly, the dual CFT description could be non-unitary, due to the possibility of negative central charge.

  5. The Schwarzschild/CFT Correspondence

    NASA Astrophysics Data System (ADS)

    Shajiee, Vahid Reza

    2016-05-01

    In this paper, the holographic description of the Schwarzschild black hole is investigated. Since the Schwarzschild solution could be mapped to the near horizon limit of the Reissner-Nordstrom solution, the dual metric is obtained by using hidden conformal symmetry. Because the near horizon spacetime admits an A d S 2 factor, a well-defined 2D (quantum) gravity, dimensionally reduced from near horizon metric, is elected. It is demonstrated that the dual CFT has a central charge c=96 M 3 which is an asymptotic conserved charge of the near horizon solution. As the most important consequence of AdS/CFT correspondence for a black hole, the entropy of Schwarzschild black hole is obtained by using Cardy formula. It is shown that the microscopic entropy of CFT is equal to the macroscopic Bekenstein-Hawking entropy of the Schwarzschild black hole.

  6. Holographic correspondence in topological superconductors

    NASA Astrophysics Data System (ADS)

    Palumbo, Giandomenico; Pachos, Jiannis K.

    2016-09-01

    We analytically derive a compatible family of effective field theories that uniquely describe topological superconductors in 3D, their 2D boundary and their 1D defect lines. We start by deriving the topological field theory of a 3D topological superconductor in class DIII, which is consistent with its symmetries. Then we identify the effective theory of a 2D topological superconductor in class D living on the gapped boundary of the 3D system. By employing the holographic correspondence we derive the effective chiral conformal field theory that describes the gapless modes living on the defect lines or effective boundary of the class D topological superconductor. We demonstrate that the chiral central charge is given in terms of the 3D winding number of the bulk which by its turn is equal to the Chern number of its gapped boundary.

  7. Applications of Bohr's correspondence principle

    NASA Astrophysics Data System (ADS)

    Crawford, Frank S.

    1989-07-01

    The Bohr correspondence-principle (cp) formula dE/dn=ℏω is presented (ω is the classical angular frequency) and its predicted energy levels En are compared to those given by the stationary state solutions of the Schrödinger equation, first for several examples in one dimension (1D), including the ``quantum bouncer,'' and then for several examples in three dimensions (3D), including the hydrogen atom and the isotropic harmonic oscillator. For the 3-D cases, the cp predictions based on classical circular orbits are compared with the ``circlelike'' Schrödinger solutions (those with the lowest energy eigenvalue for a given l) and the cp predictions based on classical ``needle'' orbits (having zero angular momentum) with the Schrödinger l=0 solutions. For the H atom and the isotropic oscillator, the cp prediction does not depend on the classical orbit chosen because of a ``degeneracy'': the fact that for these systems ω is independent of the orbit. As a more stringent test of the cp, analogous nondegenerate systems V=-k/r3/2 in place of the H-atom potential V=-e2/r and V=kr4 in place of the oscillator potential V=(1/2)mω2r2 are therefore considered. An interesting anomaly that occurs for the harmonic oscillator and its nondegenerate analog V=kr4 is encountered (but not for the H atom nor its nondegenerate analog V=-k/r3/2), wherein half of the states predicted by application of the cp to the needle orbits are ``spurious'' in that there are no corresponding Schrödinger l=0 states. The assumption that generated the spurious cp states is uncovered—a plausible, but erroneous factor of 2 in calculating the classical frequency—and thus the spurious states are eliminated.

  8. CROSS-DISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Environmental Impacts on Spiking Properties in Hodgkin-Huxley Neuron with Direct Current Stimulus

    NASA Astrophysics Data System (ADS)

    Yuan, Chang-Qing; Zhao, Tong-Jun; Zhan, Yong; Zhang, Su-Hua; Liu, Hui; Zhang, Yu-Hong

    2009-11-01

    Based on the well accepted Hodgkin-Huxley neuron model, the neuronal intrinsic excitability is studied when the neuron is subject to varying environmental temperatures, the typical impact for its regulating ways. With computer simulation, it is found that altering environmental temperature can improve or inhibit the neuronal intrinsic excitability so as to influence the neuronal spiking properties. The impacts from environmental factors can be understood that the neuronal spiking threshold is essentially influenced by the fluctuations in the environment. With the environmental temperature varying, burst spiking is realized for the neuronal membrane voltage because of the environment-dependent spiking threshold. This burst induced by changes in spiking threshold is different from that excited by input currents or other stimulus.

  9. The Development of a Noncontact Letter Input Interface “Fingual” Using Magnetic Dataset

    NASA Astrophysics Data System (ADS)

    Fukushima, Taishi; Miyazaki, Fumio; Nishikawa, Atsushi

    We have newly developed a noncontact letter input interface called “Fingual”. Fingual uses a glove mounted with inexpensive and small magnetic sensors. Using the glove, users can input letters to form the finger alphabets, a kind of sign language. The proposed method uses some dataset which consists of magnetic field and the corresponding letter information. In this paper, we show two recognition methods using the dataset. First method uses Euclidean norm, and second one additionally uses Gaussian function as a weighting function. Then we conducted verification experiments for the recognition rate of each method in two situations. One of the situations is that subjects used their own dataset; the other is that they used another person's dataset. As a result, the proposed method could recognize letters with a high rate in both situations, even though it is better to use their own dataset than to use another person's dataset. Though Fingual needs to collect magnetic dataset for each letter in advance, its feature is the ability to recognize letters without the complicated calculations such as inverse problems. This paper shows results of the recognition experiments, and shows the utility of the proposed system “Fingual”.

  10. On the Functional Neuroanatomy of Visual Word Processing: Effects of Case and Letter Deviance

    ERIC Educational Resources Information Center

    Kronbichler, Martin; Klackl, Johannes; Richlan, Fabio; Schurz, Matthias; Staffen, Wolfgang; Ladurner, Gunther; Wimmer, Heinz

    2009-01-01

    This functional magnetic resonance imaging study contrasted case-deviant and letter-deviant forms with familiar forms of the same phonological words (e.g., "TaXi" and "Taksi" vs. "Taxi") and found that both types of deviance led to increased activation in a left occipito-temporal region, corresponding to the visual word form area (VWFA). The…

  11. Faith, Friendship and Learning: Intercultural Communication in the Republic of Letters

    ERIC Educational Resources Information Center

    Austin, Kenneth; Anderson, Wendy

    2010-01-01

    This article uses the renowned antiquarian Nicolas-Claude Fabri de Peiresc (1580-1637) as a case study to examine the intellectual and religious culture of the early seventeenth century. In particular, using his extensive correspondence, it investigates the manner in which the exchange of letters could be used to reinforce the identity of one…

  12. Blue Ribbon Panel Report Cover Letter

    Cancer.gov

    The letter from NCI Acting Director Douglas R. Lowy, M.D., to Vice President Biden that accompanied the Blue Ribbon Panel final report, thanking the Vice President for his commitment to and leadership of the Cancer Moonshot.

  13. 19 CFR 207.103 - Charging letter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... interim measures, as provided for in 19 CFR 207.106. The charging letter shall include: (1) Allegations... be imposed for a prohibited act; (3) A statement that a proceeding has been initiated and that an...

  14. 19 CFR 207.103 - Charging letter.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... interim measures, as provided for in 19 CFR 207.106. The charging letter shall include: (1) Allegations... be imposed for a prohibited act; (3) A statement that a proceeding has been initiated and that an...

  15. Psychophysics of reading. XX. Linking letter recognition to reading speed in central and peripheral vision.

    PubMed

    Legge, G E; Mansfield, J S; Chung, S T

    2001-03-01

    Our goal is to link spatial and temporal properties of letter recognition to reading speed for text viewed centrally or in peripheral vision. We propose that the size of the visual span - the number of letters recognizable in a glance - imposes a fundamental limit on reading speed, and that shrinkage of the visual span in peripheral vision accounts for slower peripheral reading. In Experiment 1, we estimated the size of the visual span in the lower visual field by measuring RSVP (rapid serial visual presentation) reading times as a function of word length. The size of the visual span decreased from at least 10 letters in central vision to 1.7 letters at 15 degrees eccentricity, in good agreement with the corresponding reduction of reading speed measured by Chung and coworkers (Chung, S. T. L., Mansfield, J. S., & Legge, G. E. (1998). Psychophysics of reading. XVIII. The effect of print size on reading speed in normal peripheral vision. Vision Research, 38, 2949-2962). In Exp. 2, we measured letter recognition for trigrams (random strings of three letters) as a function of their position on horizontal lines passing through fixation (central vision) or displaced downward into the lower visual field (5, 10 and 20 degrees ). We also varied trigram presentation time. We used these data to construct visual-span profiles of letter accuracy versus letter position. These profiles were used as input to a parameter-free model whose output was RSVP reading speed. A version of this model containing a simple lexical-matching rule accounted for RSVP reading speed in central vision. Failure of this version of the model in peripheral vision indicated that people rely more on lexical inference to support peripheral reading. We conclude that spatiotemporal characteristics of the visual span limit RSVP reading speed in central vision, and that shrinkage of the visual span results in slower reading in peripheral vision.

  16. Letter to Dr. Felix Bronner

    NASA Technical Reports Server (NTRS)

    Greenleaf, John E.; Dalton, Bonnie (Technical Monitor)

    2002-01-01

    Dear Dr. Bronner: I have been reading in The Physiologist the letters from senior physiologists for many years with great interest. It is impressive that many of the respondents are still pursuing scientific endeavours in their 70's and some even in their 80's. The interesting task is to ponder the relative causative proportions of heredity and environment responsible. One wonders whether knowing something about physiology engenders longer and more productive lives? I suspect so because of the accompanying self-discipline. But another factor would seem to be the pervasive joy of working in this profession. I have been fortunate to be able to acquire the joy of physiology during my graduate studies at Illinois, and to have been able to carry it over here at NASA, Ames Research Center for the past 40 years. A truly academic style research environment at a federal research center is rare. The trick to a joyous research career is to overcome those ever-present slings and arrows of outrageous fortune with dignity whenever possible. To that end I have found solace and guidance in reading the history of warfare and its leaders, especially Sun Tsu's The Art of War and Clauswitz's On War. I became eligible for retirement in 1993, but to insure domestic tranquility and also the joy of pursuing my research hobby have continued working in the laboratory on human research. It is troubling to see that funding for individual scientists conducting human research is declining rapidly, along with their new ideas; perhaps the old ones are more comfortable. Hopefully I can provide a similar response when I'm 80! Thanks for your interest. Sincerely, John Greenleaf

  17. Resource Letter SW1: Space Weather

    NASA Astrophysics Data System (ADS)

    Baker, Daniel N.; Lanzerotti, Louis J.

    2016-03-01

    This Resource Letter describes the phenomena and effects on technological systems that are known collectively as space weather. A brief history of the topic is provided, and the scientific understandings of drivers for such phenomena are discussed. The impacts of space disturbances are summarized, and the strategies for dealing with space weather threats are examined. The Resource Letter concludes with description of approaches that have been proposed to deal with threats to our increasingly technological society.

  18. Letter to the Editor: Robert W. Evans

    NASA Astrophysics Data System (ADS)

    Johnston, A.

    2000-12-01

    I read the Letters page of the latest issue of the JBAA (2000 October) with some amusement. My very good friend Bob Evans had, according to the letter header, not only been elevated to the clergy, but had also transferred his nationality from Kiwi to Aussie. While he'll probably overlook the religious error he may not be so sanguine about being mistaken for an Australian.

  19. Types and tokens in visual letter perception.

    PubMed

    Mozer, M C

    1989-05-01

    Five experiments demonstrate that in briefly presented displays, subjects have difficulty distinguishing repeated instances of a letter or digit (multiple tokens of the same type). When subjects were asked to estimate the numerosity of a display, reports were lower for displays containing repeated letters, for example, DDDD, than for displays containing distinct letters, for example, NRVT. This homogeneity effect depends on the common visual form of adjacent letters. A distinct homogeneity effect, one that depends on the repetition of abstract letter identities, was also found: When subjects were asked to report the number of As and Es in a display, performance was poorer on displays containing two instances of a target letter, one appearing in uppercase and the other in lowercase, than on displays containing one of each target letter. This effect must be due to the repetition of identities, because visual form is not repeated in these mixed-case displays. Further experiments showed that this effect was not influenced by the context surrounding the target letters, and that it can be tied to limitations in attentional processing. The results are interpreted in terms of a model in which parallel encoding processes are capable of automatically analyzing information from several regions of the visual field simultaneously, but fail to accurately encode location information. The resulting representation is thus insufficient to distinguish one token from another because two tokens of a given type differ only in location. However, with serial attentional processing multiple tokens can be kept distinct, pointing to yet another limit on the ability to process visual information in parallel.

  20. Attentional Processing of Letter Strings by Children.

    PubMed

    Leclercq, Virginie; Siéroff, Eric

    2016-01-01

    Reading a letter string requires attentional orienting toward the beginning of the string (left-dominant orientation), followed by orienting along the string. These attentional-orienting processes differ according to the lexicality of the letter string: Sequential processes apply when reading nonwords or pseudowords, while words can be processed more globally. The aim of this study was to evaluate the development of these attentional processes involved in reading. We conducted two experiments in 6- (first grade), 7- (second grade), and 9-year-old (fourth grade) children, using a procedure that required the detection of a letter (Experiment 1) or a nonletter (Experiment 2) target in a string of five characters. The target character could occur in the second (left) or fourth (right) position in the string. Results showed an advantage for left nonletter targets as early as age 6 and of left letter targets as early as age 7. In 6-year-olds, only good readers detected a left letter target faster than a right letter target; others detected a right letter target faster. Thus, dominant orienting toward the beginning of the letter string is not fully developed in children before the second year of reading. A possibility is that beginning readers have difficulties inhibiting an attention-orienting bias toward the right visual field in linguistic tasks. The results also showed that the lexicality effect on these attentional processes develops gradually until the fourth year of reading. We believe that the procedure used in this study will be very valuable for evaluating attentional difficulties during reading acquisition. PMID:25386702

  1. Stereo Correspondence Using Moment Invariants

    NASA Astrophysics Data System (ADS)

    Premaratne, Prashan; Safaei, Farzad

    Autonomous navigation is seen as a vital tool in harnessing the enormous potential of Unmanned Aerial Vehicles (UAV) and small robotic vehicles for both military and civilian use. Even though, laser based scanning solutions for Simultaneous Location And Mapping (SLAM) is considered as the most reliable for depth estimation, they are not feasible for use in UAV and land-based small vehicles due to their physical size and weight. Stereovision is considered as the best approach for any autonomous navigation solution as stereo rigs are considered to be lightweight and inexpensive. However, stereoscopy which estimates the depth information through pairs of stereo images can still be computationally expensive and unreliable. This is mainly due to some of the algorithms used in successful stereovision solutions require high computational requirements that cannot be met by small robotic vehicles. In our research, we implement a feature-based stereovision solution using moment invariants as a metric to find corresponding regions in image pairs that will reduce the computational complexity and improve the accuracy of the disparity measures that will be significant for the use in UAVs and in small robotic vehicles.

  2. A look at the Salomé-Freud correspondence.

    PubMed

    Sirois, F

    1998-04-01

    The author notes that the changing emphasis of the correspondence between Lou Andreas-Salomé and Sigmund Freud over the years reflects certain aspects of the development of every analyst. Her contributions are shown to illustrate the evolution of the analyst's relationship with theory and the growth of his or her clinical capacity and involvement. Two phases in the analyst's clinical progression are stated to be discernible in the correspondence, marked by changes of direction that mirror the changing nature of her relationship with Freud. Theoretical considerations predominate in the first phase, while clinical aspects gradually come to the fore in the second. Freud is seen to be offering Salomé a kind of supervision by letter. Lou's underlying transference to Freud also emerges from the correspondence, its two aspects being the relationship to a big brother and to a father respectively. Freud's complementary transference to Salomé is also discussed, partly in connection with her relationship with his daughter Anna. The author's arguments are supported by extensive quotations from the correspondence, biographical works and Lou Andreas-Salomé's published diaries and reminiscences. Last but not least, her relationship with Freud in the author's view indirectly raises the issue of that of any analyst to the founder of psychoanalysis.

  3. On Coding Non-Contiguous Letter Combinations

    PubMed Central

    Dandurand, Frédéric; Grainger, Jonathan; Duñabeitia, Jon Andoni; Granier, Jean-Pierre

    2011-01-01

    Starting from the hypothesis that printed word identification initially involves the parallel mapping of visual features onto location-specific letter identities, we analyze the type of information that would be involved in optimally mapping this location-specific orthographic code onto a location-invariant lexical code. We assume that some intermediate level of coding exists between individual letters and whole words, and that this involves the representation of letter combinations. We then investigate the nature of this intermediate level of coding given the constraints of optimality. This intermediate level of coding is expected to compress data while retaining as much information as possible about word identity. Information conveyed by letters is a function of how much they constrain word identity and how visible they are. Optimization of this coding is a combination of minimizing resources (using the most compact representations) and maximizing information. We show that in a large proportion of cases, non-contiguous letter sequences contain more information than contiguous sequences, while at the same time requiring less precise coding. Moreover, we found that the best predictor of human performance in orthographic priming experiments was within-word ranking of conditional probabilities, rather than average conditional probabilities. We conclude that from an optimality perspective, readers learn to select certain contiguous and non-contiguous letter combinations as information that provides the best cue to word identity. PMID:21734901

  4. Cross-sensory correspondences and symbolism in spoken and written language.

    PubMed

    Walker, Peter

    2016-09-01

    Lexical sound symbolism in language appears to exploit the feature associations embedded in cross-sensory correspondences. For example, words incorporating relatively high acoustic frequencies (i.e., front/close rather than back/open vowels) are deemed more appropriate as names for concepts associated with brightness, lightness in weight, sharpness, smallness, speed, and thinness, because higher pitched sounds appear to have these cross-sensory features. Correspondences also support prosodic sound symbolism. For example, speakers might raise the fundamental frequency of their voice to emphasize the smallness of the concept they are naming. The conceptual nature of correspondences and their functional bidirectionality indicate they should also support other types of symbolism, including a visual equivalent of prosodic sound symbolism. For example, the correspondence between auditory pitch and visual thinness predicts that a typeface with relatively thin letter strokes will reinforce a word's reference to a relatively high pitch sound (e.g., squeal). An initial rating study confirms that the thinness-thickness of a typeface's letter strokes accesses the same cross-sensory correspondences observed elsewhere. A series of speeded word classification experiments then confirms that the thinness-thickness of letter strokes can facilitate a reader's comprehension of the pitch of a sound named by a word (thinner letter strokes being appropriate for higher pitch sounds), as can the brightness of the text (e.g., white-on-gray text being appropriate for the names of higher pitch sounds). It is proposed that the elementary visual features of text are represented in the same conceptual system as word meaning, allowing cross-sensory correspondences to support visual symbolism in language. (PsycINFO Database Record

  5. Minister Peng answers correspondents' questions.

    PubMed

    1991-02-01

    Following a press conference where she presented the results of the 1990 census and the accomplishments of China's family planning program, Peng Peiyun, minister of the State Family Planning Commission, and other officials answered the questions of Chinese and foreign correspondents. Asked about the implementation of family planning in rural areas, Peng explained that while the 1-child policy has been followed, farmers with only 1 daughter have been allowed a second child. Nonetheless, the total fertility rate (TFR) of rural women has fallen bellow 4. On the issue of abortion, an official explained that for the past few years, there have been 10 million abortions annually. Abortion, however, is used only when contraception fails. Despite China's impressive achievements in curbing population growth, Peng noted that the country still faces serious problems. As the country enters its 8th 5-year plan, China will undergo a baby boom. An average of 17 million births each year is expected throughout the plan's duration. Peng acknowledged that the previous target of controlling China's population to 1.2 billion by the year 2000 will not be achieved. Under the new plan, which hopes to reduce the TFR from 2.35 in 1989 to 2.0 by the turn of the century, calls for the population to stabilize somewhere between 1.5 and 1.6 billion. Peng also answered questions concerning abuses by family planning workers. She stressed that China's family planning program is voluntary, although economic disincentives are used. Furthermore, Peng addressed issues concerning religion and family planning, infanticide, the safety of contraceptives, and concerns over the ageing of the population. PMID:12284670

  6. 12 CFR 337.2 - Standby letters of credit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Standby letters of credit. 337.2 Section 337.2... UNSAFE AND UNSOUND BANKING PRACTICES § 337.2 Standby letters of credit. (a) Definition. As used in this section, the term standby letter of credit means any letter of credit, or similar arrangement...

  7. 48 CFR 1602.170-10 - Letter of credit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false Letter of credit. 1602.170... Terms 1602.170-10 Letter of credit. Letter of credit means the method by which certain carriers, and... available. For each carrier participating in the letter of credit arrangement for payment under this...

  8. 12 CFR 337.2 - Standby letters of credit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Standby letters of credit. 337.2 Section 337.2... UNSAFE AND UNSOUND BANKING PRACTICES § 337.2 Standby letters of credit. (a) Definition. As used in this section, the term standby letter of credit means any letter of credit, or similar arrangement...

  9. 19 CFR 177.9 - Effect of ruling letters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Effect of ruling letters. 177.9 Section 177.9... TREASURY (CONTINUED) ADMINISTRATIVE RULINGS General Ruling Procedure § 177.9 Effect of ruling letters. (a) Effect of ruling letters generally. A ruling letter issued by the Customs Service under the provisions...

  10. 19 CFR 177.9 - Effect of ruling letters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... classification of an article under the provisions of the Harmonized Tariff Schedule of the United States will be... letter. (3) Valuation rulings. Each ruling letter setting forth the proper valuation of an article under... letter. Each ruling letter setting forth a determination as to whether or not the primary object of...

  11. When Writing Impairs Reading: Letter Perception's Susceptibility to Motor Interference

    ERIC Educational Resources Information Center

    James, Karin H.; Gauthier, Isabel

    2009-01-01

    The effect of writing on the concurrent visual perception of letters was investigated in a series of studies using an interference paradigm. Participants drew shapes and letters while simultaneously visually identifying letters and shapes embedded in noise. Experiments 1-3 demonstrated that letter perception, but not the perception of shapes, was…

  12. Neural Correlates of Top-Down Letter Processing

    ERIC Educational Resources Information Center

    Liu, Jiangang; Li, Jun; Zhang, Hongchuan; Rieth, Cory A.; Huber, David E.; Li, Wu; Lee, Kang; Tian, Jie

    2010-01-01

    This fMRI study investigated top-down letter processing with an illusory letter detection task. Participants responded whether one of a number of different possible letters was present in a very noisy image. After initial training that became increasingly difficult, they continued to detect letters even though the images consisted of pure noise,…

  13. Representation of Letter Position in Spelling: Evidence from Acquired Dysgraphia

    ERIC Educational Resources Information Center

    Fischer-Baum, Simon; McCloskey, Michael; Rapp, Brenda

    2010-01-01

    The graphemic representations that underlie spelling performance must encode not only the identities of the letters in a word, but also the positions of the letters. This study investigates how letter position information is represented. We present evidence from two dysgraphic individuals, CM and LSS, who perseverate letters when spelling: that…

  14. 76 FR 65703 - List of Correspondence

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... for the deaf (TDD), you can call the Federal Relay Service (FRS), toll free, at 1-800-877-8339... hearing officer, a local educational agency (LEA) can reach an agreement to provide tuition reimbursement...: Evaluations, Parental Consent and Reevaluations Letter dated January 6, 2011, to Lehigh University...

  15. IDEA: La Correspondencia Anonima (Anonymous Correspondence).

    ERIC Educational Resources Information Center

    Lopez-Gomez, Coral

    1997-01-01

    Discusses the usefulness to second language learning of an activity in which students assume a pen name and write letters under that name in the language studied in order to motivate their interest in the language and accelerate their mastery of it. (CK)

  16. Letter from President Millard Fillmore to the Emperor of Japan: The President's Letter Opened a Closed Country to the West

    ERIC Educational Resources Information Center

    Pinkert, Marvin; Potter, Lee Ann

    2004-01-01

    In 1852, Commodore Matthew C. Perry of the U.S. Navy sailed to Japan with instructions to deliver a letter from President Millard Fillmore to the Emperor. The letter eventually led to the 1854 Treaty of Kanagawa and the opening of Japan to trade with Western nations. The State Department's letter book copy of the letter is featured in this…

  17. Corresponding Angle Feedback in an innovative weighted transportation system

    NASA Astrophysics Data System (ADS)

    Dong, Chuanfei; Ma, Xu

    2010-05-01

    The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. In this Letter, we study dynamics of traffic flow with real-time information. The influence of a feedback strategy named Corresponding Angle Feedback Strategy (CAFS) is introduced, based on a two-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.

  18. ERP Correlates of Letter Identity and Letter Position Are Modulated by Lexical Frequency

    ERIC Educational Resources Information Center

    Vergara-Martinez, Marta; Perea, Manuel; Gomez, Pablo; Swaab, Tamara Y.

    2013-01-01

    The encoding of letter position is a key aspect in all recently proposed models of visual-word recognition. We analyzed the impact of lexical frequency on letter position assignment by examining the temporal dynamics of lexical activation induced by pseudowords extracted from words of different frequencies. For each word (e.g., BRIDGE), we created…

  19. Letter-Transposition Effects Are Not Universal: The Impact of Transposing Letters in Hebrew

    ERIC Educational Resources Information Center

    Velan, Hadas; Frost, Ram

    2009-01-01

    We examined the effects of letter-transposition in Hebrew in three masked-priming experiments. Hebrew, like English has an alphabetic orthography where sequential and contiguous letter strings represent phonemes. However, being a Semitic language it has a non-concatenated morphology that is based on root derivations. Experiment 1 showed that…

  20. Alphabetic skills in preschool: a preliminary study of letter naming and letter writing.

    PubMed

    Molfese, Victoria J; Beswick, Jennifer; Molnar, Andrew; Jacobi-Vessels, Jill

    2006-01-01

    Development of letter naming and writing (skills in writing first name, dictated and copied letters, and dictated and copied numbers) was examined in 79 preschool children (M age = 56 months). Skills were assessed in the fall to determine the status of these procedural skills that are components of alphabetic knowledge at the start of the school year. Children with high letter-naming scores also had high scores on letter writing, including dictated or copied letters and writing some or all of the letters of their names. Letter-naming skills were related to number-writing skills whether the numbers were dictated or copied. The highest writing scores were found for first name writing compared to writing or copying letters and numbers. A focus on the development of procedural knowledge in the preschool period may yield the hopep for impacts on later reading skills that has not been found in curricula emphasizing conceptual knowledge (e.g., knowledge of print concepts, book conventions).

  1. Can "CANISO" Activate "CASINO"? Transposed-Letter Similarity Effects with Nonadjacent Letter Positions

    ERIC Educational Resources Information Center

    Perea, Manuel; Lupker, Stephen J.

    2004-01-01

    Nonwords created by transposing two "adjacent" letters (i.e., transposed-letter (TL) nonwords like "jugde") are very effective at activating the lexical representation of their base words. This fact poses problems for most computational models of word recognition (e.g., the interactive-activation model and its extensions), which assume that exact…

  2. Impaired acquisition of novel grapheme-color correspondences in synesthesia.

    PubMed

    Brang, David; Ghiam, Michael; Ramachandran, Vilayanur S

    2013-01-01

    Grapheme-color synesthesia is a neurological phenomenon in which letters and numbers (graphemes) consistently evoke particular colors (e.g., A may be experienced as red). These sensations are thought to arise through the cross-activation of grapheme processing regions in the fusiform gyrus and color area V4, supported by anatomical and functional imaging. However, the developmental onset of grapheme-color synesthesia remains elusive as research in this area has largely relied on self-report of these experiences in children. One possible account suggests that synesthesia is present at or near birth and initially binds basic shapes and forms to colors, which are later refined to grapheme-color associations through experience. Consistent with this view, studies show that similarly shaped letters and numbers tend to elicit similar colors in synesthesia and that some synesthetes consciously associate basic shapes with colors; research additionally suggests that synesthetic colors can emerge for newly learned characters with repeated presentation. This model further predicts that the initial shape-color correspondences in synesthesia may persist as implicit associations, driving the acquisition of colors for novel characters. To examine the presence of latent color associations for novel characters, synesthetes and controls were trained on pre-defined associations between colors and complex shapes, on the assumption that the prescribed shape-color correspondences would on average differ from implicit synesthetic associations. Results revealed synesthetes were less accurate than controls to learn novel shape-color associations, consistent with our suggestion that implicit form-color associations conflicted with the learned pairings.

  3. Letters in time and retinotopic space.

    PubMed

    Adelman, James S

    2011-10-01

    Various phenomena in tachistoscopic word identification and priming (WRODS and LTRS are confused with and prime WORDS and LETTERS) suggest that position-specific channels are not used in the processing of letters in words. Previous approaches to this issue have sought alternative matching rules because they have assumed that these phenomena reveal which stimuli are good but imperfect matches to a particular word-such imperfect matches being taken by the word recognition system as partial evidence for that word. The new Letters in Time and Retinotopic Space model (LTRS) makes the alternative assumption that these phenomena reveal the rates at which different features of the stimulus are extracted, because the stimulus is ambiguous when some features are missing from the percept. LTRS is successfully applied to tachistoscopic identification and form priming data with manipulations of duration and target-foil and prime-target relationships.

  4. Letters in the forest: global precedence effect disappears for letters but not for non-letters under reading-like conditions

    PubMed Central

    Lachmann, Thomas; Schmitt, Andreas; Braet, Wouter; van Leeuwen, Cees

    2014-01-01

    Normally skilled reading involves special processing strategies for letters, which are habitually funneled into an abstract letter code. On the basis of previous studies we argue that this habit leads to the preferred usage of an analytic strategy for the processing of letters, while non-letters are preferably processed via a holistic strategy. The well-known global precedence effect (GPE) seems to contradict to this assumption, since, with compound, hierarchical figures, including letter items, faster responses are observed to the global than to the local level of the figure, as well as an asymmetric interference effect from global to local level. We argue that with letters these effects depend on presentation conditions; only when they elicit the processing strategies automatized for reading, an analytic strategy for letters in contrast to non-letters is to be expected. We compared the GPE for letters and non-letters in central viewing, with the global stimulus size close to the functional visual field in whole word reading (6.5° of visual angle) and local stimuli close to the critical size for fluent reading of individual letters (0.5° of visual angle). Under these conditions, the GPE remained robust for non-letters. For letters, however, it disappeared: letters showed no overall response time advantage for the global level and symmetric congruence effects (local-to-global as well as global-to-local interference). We interpret these results as according to the view that reading is based on resident analytic visual processing strategies for letters. PMID:25101012

  5. Letters in the forest: global precedence effect disappears for letters but not for non-letters under reading-like conditions.

    PubMed

    Lachmann, Thomas; Schmitt, Andreas; Braet, Wouter; van Leeuwen, Cees

    2014-01-01

    Normally skilled reading involves special processing strategies for letters, which are habitually funneled into an abstract letter code. On the basis of previous studies we argue that this habit leads to the preferred usage of an analytic strategy for the processing of letters, while non-letters are preferably processed via a holistic strategy. The well-known global precedence effect (GPE) seems to contradict to this assumption, since, with compound, hierarchical figures, including letter items, faster responses are observed to the global than to the local level of the figure, as well as an asymmetric interference effect from global to local level. We argue that with letters these effects depend on presentation conditions; only when they elicit the processing strategies automatized for reading, an analytic strategy for letters in contrast to non-letters is to be expected. We compared the GPE for letters and non-letters in central viewing, with the global stimulus size close to the functional visual field in whole word reading (6.5° of visual angle) and local stimuli close to the critical size for fluent reading of individual letters (0.5° of visual angle). Under these conditions, the GPE remained robust for non-letters. For letters, however, it disappeared: letters showed no overall response time advantage for the global level and symmetric congruence effects (local-to-global as well as global-to-local interference). We interpret these results as according to the view that reading is based on resident analytic visual processing strategies for letters.

  6. Resource Letter CF-1: Casimir Force

    SciTech Connect

    Lamoreaux, S.K.

    1999-10-01

    This resource letter provides an introductory guide to the literature on the Casimir force. Journal articles and books are cited for the following topics: introductory articles and books, calculations, dynamical Casimir effect, mechanical analogs, applications, and experiments. {copyright} {ital 1999 American Association of Physics Teachers.}

  7. [Pavlov's unknown letter to L. A. Orbely].

    PubMed

    Budko, A A; Nazartsev, B I

    2012-07-01

    The text of Ivan P. Pavlov's unknown letter addressed to Leon A. Orbely is published for the first time. The document is kept in the Fund of the Military Medical Museum of the Military Medical Academy named after Sergey M. Kirov.

  8. 7 CFR 1773.33 - Management letter.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... under 7 CFR part 1744, subpart E; (ii) The requirement for a borrower to prepare and furnish mortgagees... 7 Agriculture 12 2011-01-01 2011-01-01 false Management letter. 1773.33 Section 1773.33... AGRICULTURE (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Reporting Requirements § 1773.33...

  9. 7 CFR 1773.33 - Management letter.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... under 7 CFR part 1744, subpart E; (ii) The requirement for a borrower to prepare and furnish mortgagees... 7 Agriculture 12 2013-01-01 2013-01-01 false Management letter. 1773.33 Section 1773.33... AGRICULTURE (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Reporting Requirements § 1773.33...

  10. 7 CFR 1773.33 - Management letter.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... under 7 CFR part 1744, subpart E; (ii) The requirement for a borrower to prepare and furnish mortgagees... 7 Agriculture 12 2012-01-01 2012-01-01 false Management letter. 1773.33 Section 1773.33... AGRICULTURE (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Reporting Requirements § 1773.33...

  11. 24 CFR 241.1010 - Feasibility letter.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Feasibility letter. 241.1010 Section 241.1010 Housing and Urban Development Regulations Relating to Housing and Urban Development... URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER...

  12. Employer Preferences for Resumes and Cover Letters

    ERIC Educational Resources Information Center

    Schullery, Nancy M.; Ickes, Linda; Schullery, Stephen E.

    2009-01-01

    This article reports the results of a survey of employers' preferences for resume style, resume delivery method, and cover letters. Employers still widely prefer the standard chronological resume, with only 3% desiring a scannable resume. The vast majority of employers prefer electronic delivery, either by email (46%) or at the company's Web site…

  13. An Open Letter to Ninth Graders

    ERIC Educational Resources Information Center

    Sullivan, Patrick

    2009-01-01

    Many studies and reports in recent years have argued that there's an important "expectations gap" between the skills students are typically bringing to college and what college teachers think students should be bringing with them to college. This article, presented in the form of an open letter to first-year high school students, is an attempt…

  14. 42 CFR 93.202 - Charge letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Charge letter. 93.202 Section 93.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON...

  15. 42 CFR 93.202 - Charge letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Charge letter. 93.202 Section 93.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON...

  16. 42 CFR 93.202 - Charge letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Charge letter. 93.202 Section 93.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON...

  17. 42 CFR 93.202 - Charge letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Charge letter. 93.202 Section 93.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON...

  18. 42 CFR 93.202 - Charge letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Charge letter. 93.202 Section 93.202 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON...

  19. Suspending Damage: A Letter to Communities

    ERIC Educational Resources Information Center

    Tuck, Eve

    2009-01-01

    In this open letter, Eve Tuck calls on communities, researchers, and educators to reconsider the long-term impact of "damage-centered" research--research that intends to document peoples' pain and brokenness to hold those in power accountable for their oppression. This kind of research operates with a flawed theory of change: it is often used to…

  20. Letters of a Slave Turned Union Soldier.

    ERIC Educational Resources Information Center

    Humanities, 1990

    1990-01-01

    Discusses the influx of Black soldiers into the Union army following the Emancipation Proclamation. Concentrates on the case of Private Spotswood Rice. Provides a short history of Rice, including copies of Rice's letters to his enslaved daughters, the daughter's slaveholders, and an angry retort from the slaveowner to the federal commander in…

  1. Readerly and Writerly "Letters from the Park."

    ERIC Educational Resources Information Center

    Conde, Susana

    1993-01-01

    Discusses in depth the film "Cartas del parque" ("Letters from the Park"), the first of six films in the "Amores Dificiles" series. Notes that the film is pervaded by the traditional overdetermination of gender roles. Suggests that an intrusive and authoritative narrator makes of this both a "readerly" and a "writerly" film. (RS)

  2. The "Best" of the Harvard Education Letter.

    ERIC Educational Resources Information Center

    Steinberg, Adria, Ed.

    1992-01-01

    This document consists of a selection of the best articles previously published in the "Harvard Education Letter." It contains the following articles (without citing the issue in which they originally appeared): (1) "School-Parent Relationships that Work: An Interview with James Comer"; (2) "Unpopular Children"; (3) "Kindergarten: Producing Early…

  3. Crowding Affects Letters and Symbols Differently

    ERIC Educational Resources Information Center

    Grainger, Jonathan; Tydgat, Ilse; Issele, Joanna

    2010-01-01

    Five experiments examined crowding effects with letter and symbol stimuli. Experiments 1 through 3 compared 2-alternative forced-choice (2AFC) identification accuracy for isolated targets presented left and right of fixation with targets flanked either by 2 other items of the same category or a single item situated to the right or left of targets.…

  4. Introduction to Literary Criticism: "The Scarlet Letter."

    ERIC Educational Resources Information Center

    Lawrence, Lisa

    This course seeks to provide high school students the opportunity to sharpen their critical thinking skills and use of language through acquaintance with some ideas of literary criticism. The course features Nathaniel Hawthorne's "The Scarlet Letter," assuming that the students have just finished reading that American classic novel. The course…

  5. "Physical Review Letters" in the Classroom

    ERIC Educational Resources Information Center

    Angiolillo, Paul J.; Lynch, Jonathan

    2010-01-01

    Ask any physicist what the preeminent journal in the field is, and I think the almost unanimous answer will be "Physical Review Letters" ("PRL"). This weekly journal of the American Physical Society publishes high-impact research from all the major subdisciplines of physics. This journal is not the one you would think is the first place a high…

  6. Text legibility and the letter superiority effect.

    PubMed

    Sheedy, James E; Subbaram, Manoj V; Zimmerman, Aaron B; Hayes, John R

    2005-01-01

    Effects of font design and electronic display parameters upon text legibility were determined using a threshold size method. Participants' visual acuity (inverse of the minimum detection size, representing the threshold legibility for each condition) was measured using upper- and lowercase letters and lowercase words in combinations of 6 fonts, 3 font-smoothing modes, 4 font sizes, 10 pixel heights, and 4 stroke widths. Individual lowercase letters were 10% to 20% more legible than lowercase words (i.e., lowercase words must be 10%-20% larger to have the same threshold legibility). This letter superiority effect suggests that individual letters play a large role and word shape plays a smaller role, if any, in word identification at threshold. Pixel height, font, stroke width, and font smoothing had significant main effects on threshold legibility. Optimal legibility was attained at 9 pixels (10 points). Verdana and Arial were the most legible fonts; Times New Roman and Franklin were least legible. Subpixel rendering (ClearType) improved threshold legibility for some fonts and, in combination with Verdana, was the most legible condition. Increased stroke width (bold) improved threshold legibility but only at the thinnest width tested. Potential applications of this research include optimization of font design for legibility and readability. PMID:16553067

  7. 7 CFR 1773.33 - Management letter.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... under 7 CFR part 1744, subpart E; (ii) The requirement for a borrower to prepare and furnish mortgagees... 7 Agriculture 12 2010-01-01 2010-01-01 false Management letter. 1773.33 Section 1773.33... AGRICULTURE (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Reporting Requirements § 1773.33...

  8. [Pavlov's unknown letter to L. A. Orbely].

    PubMed

    Budko, A A; Nazartsev, B I

    2012-07-01

    The text of Ivan P. Pavlov's unknown letter addressed to Leon A. Orbely is published for the first time. The document is kept in the Fund of the Military Medical Museum of the Military Medical Academy named after Sergey M. Kirov. PMID:23074838

  9. Resource Letter SE-1: Solar Energy

    ERIC Educational Resources Information Center

    McDaniels, D. K.; Throop, M. J.

    1976-01-01

    This is one of a series of Resource Letters on different topics intended to guide college physicists, astronomers, and other scientists to some of the literature and other teaching aids that may help improve course contents in specified fields. (Author/CP)

  10. Perceputal Span for Letter Distinctions During Reading.

    ERIC Educational Resources Information Center

    Underwood, N. R.; McConkie, G. W.

    1985-01-01

    Fifteen college students read passages from a cathode-ray tube as their eye movements were monitored in a study that investigated the size of the visual region within which they used visual information to distinguish among letters as they read. (HOD)

  11. Letters from Roger: Exercises in Communication.

    ERIC Educational Resources Information Center

    Campbell, Russell N.; Bracy, Maryruth

    This book is designed for low-intermediate to advanced students of English as a second language. It provides a look at the world that awaits the foreign student who is to be suddenly immersed in an English-speaking society. The format involves a number of letters written by an American university student to a foreign student planning a trip to the…

  12. INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Spiral Wave in Small-World Networks of Hodgkin-Huxley Neurons

    NASA Astrophysics Data System (ADS)

    Ma, Jun; Yang, Li-Jian; Wu, Ying; Zhang, Cai-Rong

    2010-09-01

    The effect of small-world connection and noise on the formation and transition of spiral wave in the networks of Hodgkin-Huxley neurons are investigated in detail. Some interesting results are found in our numerical studies. i) The quiescent neurons are activated to propagate electric signal to others by generating and developing spiral wave from spiral seed in small area. ii) A statistical factor is defined to describe the collective properties and phase transition induced by the topology of networks and noise. iii) Stable rotating spiral wave can be generated and keeps robust when the rewiring probability is below certain threshold, otherwise, spiral wave can not be developed from the spiral seed and spiral wave breakup occurs for a stable rotating spiral wave. iv) Gaussian white noise is introduced on the membrane of neurons to study the noise-induced phase transition on spiral wave in small-world networks of neurons. It is confirmed that Gaussian white noise plays active role in supporting and developing spiral wave in the networks of neurons, and appearance of smaller factor of synchronization indicates high possibility to induce spiral wave.

  13. Event Related Potentials Reveal Early Phonological and Orthographic Processing of Single Letters in Letter-Detection and Letter-Rhyme Paradigms

    PubMed Central

    Bann, Sewon A.; Herdman, Anthony T.

    2016-01-01

    Introduction: When and where phonological processing occurs in the brain is still under some debate. Most paired-rhyme and phonological priming studies used word stimuli, which involve complex neural networks for word recognition and semantics. This study investigates early (<300 ms) and late (>300 ms) orthographic and phonological processing of letters. Methods: Fifteen participants aged 20–35 engaged in three two-forced choice experiments, one letter-detection (LetterID) and two letter-rhyme (Paired-Rhyme and Letter-Rhyme) tasks. From the EEG recordings, event related potential (ERP) differences within and across task stimuli were found. We also calculated the global field power (GFP) for each participant. Accuracies and reaction times were also measured from their button presses for each task. Results: Behavioral: Reaction times were 18 ms faster to letter than pseudoletter stimuli, and 27 ms faster to rhyme than nonrhyme stimuli. ERP/GFP: In the LetterID task, grand-mean evoked potentials (EPs) showed typical P1, N1, P2, and P3 waveform morphologies to letter and pseudoletter stimuli, with GFPs to pseudoletters being greater than letters from 160–600 ms. Across both rhyme tasks, there were greater negativities for nonrhyme than for rhyme stimuli at 145 ms and 426 ms. The P2 effect for rhyme stimuli was smaller than letter stimuli when compared across tasks. Conclusion: Differences in early processing of letters vs. pseudoletters between 130–190 ms suggest that letters are processed earlier and perhaps faster in the brain than pseudoletters. The P2 effect between letter and rhyme stimuli likely reflect sublexical phonological processing. Together, findings from our study fill in evidence for the temporal dynamics of orthographic and phonological processing of single letters. PMID:27148023

  14. 50 CFR 216.277 - Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MAMMALS Taking Marine Mammals Incidental to U.S. Navy Training in the Southern California Range Complex (SOCAL Range Complex) § 216.277 Letters of Authorization. (a) A Letter of Authorization, unless...

  15. 50 CFR 218.7 - Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MAMMALS Taking Marine Mammals Incidental to U.S. Navy Training in the Virginia Capes Range Complex (VACAPES Range Complex) § 218.7 Letters of Authorization. (a) A Letter of Authorization, unless...

  16. 50 CFR 218.16 - Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... MAMMALS Taking Marine Mammals Incidental to U.S. Navy Training in the Jacksonville Range Complex (JAX Range Complex) § 218.16 Letters of Authorization. (a) A Letter of Authorization, unless suspended...

  17. 50 CFR 216.257 - Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND IMPORTING OF MARINE... Mexico § 216.257 Letters of Authorization. (a) A Letter of Authorization, unless suspended or...

  18. 50 CFR 218.237 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.237 Applications for Letters of... scheduled to begin conducting SURTASS LFA sonar operations or the previous Letter of Authorization...

  19. 50 CFR 218.237 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.237 Applications for Letters of... scheduled to begin conducting SURTASS LFA sonar operations or the previous Letter of Authorization...

  20. 50 CFR 216.187 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Array Sensor System Low Frequency Active (SURTASS LFA sonar) Sonar § 216.187 Applications for Letters of... scheduled to begin conducting SURTASS LFA sonar operations or the previous Letter of Authorization...

  1. 50 CFR 218.237 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.237 Applications for Letters of... scheduled to begin conducting SURTASS LFA sonar operations or the previous Letter of Authorization...

  2. 50 CFR 216.187 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Array Sensor System Low Frequency Active (SURTASS LFA sonar) Sonar § 216.187 Applications for Letters of... scheduled to begin conducting SURTASS LFA sonar operations or the previous Letter of Authorization...

  3. 75 FR 23764 - Correspondent Concentration Risks

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-04

    ... more normal market functioning resumes. 74 FR 25,626 (May 29, 2009). The Board will consider these... deposit insurance (FDI)).\\2\\ 500,000 Due from DDA with correspondent's two affiliated IDIs (less FDI).\\2\\ 750,000 CDs issued by correspondent bank (less FDI). 250,000 CDs issued by one of correspondent's...

  4. 31 CFR 561.306 - Correspondent account.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Correspondent account. 561.306 Section 561.306 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 561.306 Correspondent account. The term correspondent account means an account established by...

  5. 31 CFR 561.306 - Correspondent account.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Correspondent account. 561.306 Section 561.306 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 561.306 Correspondent account. The term correspondent account means an account established by...

  6. 31 CFR 561.306 - Correspondent account.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Correspondent account. 561.306 Section... Definitions § 561.306 Correspondent account. For purposes of this part, the term correspondent account means an account established by a U.S. financial institution for a foreign financial institution to...

  7. 31 CFR 561.306 - Correspondent account.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Correspondent account. 561.306 Section 561.306 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF... Definitions § 561.306 Correspondent account. The term correspondent account means an account established by...

  8. 28 CFR 540.19 - Legal correspondence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Legal correspondence. 540.19 Section 540... WITH PERSONS IN THE COMMUNITY Correspondence § 540.19 Legal correspondence. (a) Staff shall mark each envelope of incoming legal mail (mail from courts or attorneys) to show the date and time of receipt,...

  9. 28 CFR 540.19 - Legal correspondence.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Legal correspondence. 540.19 Section 540... WITH PERSONS IN THE COMMUNITY Correspondence § 540.19 Legal correspondence. (a) Staff shall mark each envelope of incoming legal mail (mail from courts or attorneys) to show the date and time of receipt,...

  10. 34 CFR 690.66 - Correspondence study.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 4 2012-07-01 2012-07-01 false Correspondence study. 690.66 Section 690.66 Education... § 690.66 Correspondence study. (a) An institution calculates the Federal Pell Grant for a payment period for a student in a program of study offered by correspondence courses without terms, but not...

  11. 34 CFR 690.66 - Correspondence study.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 4 2014-07-01 2014-07-01 false Correspondence study. 690.66 Section 690.66 Education... § 690.66 Correspondence study. (a) An institution calculates the Federal Pell Grant for a payment period for a student in a program of study offered by correspondence courses without terms, but not...

  12. 34 CFR 690.66 - Correspondence study.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 4 2013-07-01 2013-07-01 false Correspondence study. 690.66 Section 690.66 Education... § 690.66 Correspondence study. (a) An institution calculates the Federal Pell Grant for a payment period for a student in a program of study offered by correspondence courses without terms, but not...

  13. 34 CFR 690.66 - Correspondence study.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 4 2011-07-01 2011-07-01 false Correspondence study. 690.66 Section 690.66 Education... § 690.66 Correspondence study. (a) An institution calculates the Federal Pell Grant for a payment period for a student in a program of study offered by correspondence courses without terms, but not...

  14. `Dear Professor Dyson': Twenty years of correspondence between Freeman Dyson and undergraduate students

    NASA Astrophysics Data System (ADS)

    Neuenschwander, Dwight E.

    2014-03-01

    For twenty years the students in my "Science, Technology, and Society" course, where we use Disturbing the Universe as a textbook, have corresponded with Professor Dyson. That someone of Professor Dyson's standing consistently makes a priority of promptly answering the letters of undergraduate students from all academic majors, and does so with grace and kindness, insight and wisdom, offers a personal glimpse into his character and integrity. On behalf of my students, and as a way of publicly thanking Professor Dyson for participating in our course conversations, I am honored to share samples of our correspondence with him over the years, including student reflections on his involvement in their education.

  15. `DEAR Professor DYSON:' Twenty Years of Correspondence Between Freeman Dyson and Undergraduate Students

    NASA Astrophysics Data System (ADS)

    Neuenschwander, Dwight E.

    2014-04-01

    For twenty years the students in my "Science, Technology, and Society" course, where we use Disturbing the Universe as a textbook, have corresponded with Professor Dyson. That someone of Professor Dyson's standing consistently makes a priority of promptly answering the letters of undergraduate students from all academic majors, and does so with grace and kindness, insight and wisdom, offers a personal glimpse into his character and integrity. On behalf of my students, and as a way of publicly thanking Professor Dyson for participating in our course conversations, I am honored to share samples of our correspondence with him over the years, including student reflections on his involvement in their education.

  16. Item Response Analysis of Uppercase and Lowercase Letter Name Knowledge

    ERIC Educational Resources Information Center

    Bowles, Ryan P.; Pentimonti, Jill M.; Gerde, Hope K.; Montroy, Janelle J.

    2014-01-01

    Letter name knowledge in the preschool ages is a strong predictor of later reading ability, but little is known about the psychometric characteristics of uppercase and lowercase letters considered together. Data from 1,113 preschoolers from diverse backgrounds on both uppercase and lowercase letter name knowledge were analyzed using Item Response…

  17. 47 CFR 54.1007 - Letter of credit.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 3 2012-10-01 2012-10-01 false Letter of credit. 54.1007 Section 54.1007... SERVICE Mobility Fund § 54.1007 Letter of credit. (a) Before being authorized to receive Mobility Fund Phase I support, a winning bidder shall obtain an irrevocable standby letter of credit which shall...

  18. 31 CFR 535.416 - Letters of credit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Letters of credit. 535.416 Section 535... § 535.416 Letters of credit. (a) Question. Prior to the effective date, a bank subject to the jurisdiction of the United States has issued or confirmed a documentary letter of credit for a...

  19. 48 CFR 52.228-14 - Irrevocable Letter of Credit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Credit. 52.228-14 Section 52.228-14 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION....228-14 Irrevocable Letter of Credit. As prescribed in 28.204-4, insert the following clause: Irrevocable Letter of Credit (DEC 1999) (a) “Irrevocable letter of credit” (ILC), as used in this...

  20. 31 CFR 535.416 - Letters of credit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Letters of credit. 535.416 Section 535... § 535.416 Letters of credit. (a) Question. Prior to the effective date, a bank subject to the jurisdiction of the United States has issued or confirmed a documentary letter of credit for a...

  1. 47 CFR 54.1007 - Letter of credit.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 3 2013-10-01 2013-10-01 false Letter of credit. 54.1007 Section 54.1007... SERVICE Mobility Fund § 54.1007 Letter of credit. (a) Before being authorized to receive Mobility Fund Phase I support, a winning bidder shall obtain an irrevocable standby letter of credit which shall...

  2. 31 CFR 360.7 - Chain letters prohibited.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Chain letters prohibited. 360.7... STATES SAVINGS BONDS, SERIES I Registration § 360.7 Chain letters prohibited. The issuance of bonds in the furtherance of a chain letter, pyramid, or similar scheme is against the public interest and...

  3. 31 CFR 353.8 - Chain letters prohibited.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Chain letters prohibited. 353.8... STATES SAVINGS BONDS, SERIES EE AND HH Registration § 353.8 Chain letters prohibited. The issuance of bonds in the furtherance of a chain letter or pyramid scheme is considered to be against the...

  4. 33 CFR 401.68 - Explosives permission letter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Explosives permission letter. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.68 Explosives permission letter. (a) A Seaway Explosives Permission Letter is required for an explosive vessel in...

  5. 33 CFR 401.68 - Explosives Permission Letter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Explosives Permission Letter. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.68 Explosives Permission Letter. (a) A Seaway Explosives Permission Letter is required for an explosive vessel in...

  6. 33 CFR 401.68 - Explosives Permission Letter.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Explosives Permission Letter. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.68 Explosives Permission Letter. (a) A Seaway Explosives Permission Letter is required for an explosive vessel in...

  7. 33 CFR 401.68 - Explosives Permission Letter.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Explosives Permission Letter. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.68 Explosives Permission Letter. (a) A Seaway Explosives Permission Letter is required for an explosive vessel in...

  8. 33 CFR 401.68 - Explosives Permission Letter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Explosives Permission Letter. 401..., DEPARTMENT OF TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Dangerous Cargo § 401.68 Explosives Permission Letter. (a) A Seaway Explosives Permission Letter is required for an explosive vessel in...

  9. 19 CFR 177.9 - Effect of ruling letters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Effect of ruling letters. 177.9 Section 177.9 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) ADMINISTRATIVE RULINGS General Ruling Procedure § 177.9 Effect of ruling letters. (a) Effect of ruling letters generally. A...

  10. The Distribution of Information within Letters. Technical Report No. 215.

    ERIC Educational Resources Information Center

    Navon, David; Shimron, Joseph

    Two experiments were designed to study the relative importance of various letter segments in letter recognition. One experiment was conducted with 24 subjects and the English alphabet, the other with 15 subjects and the Hebrew alphabet. In each experiment a letter was presented for identification, but was preceded by a brief presentation of either…

  11. 19 CFR 162.4 - Search for letters.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 2 2011-04-01 2011-04-01 false Search for letters. 162.4 Section 162.4 Customs... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Inspection, Examination, and Search § 162.4 Search for letters. A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary...

  12. 19 CFR 162.4 - Search for letters.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Search for letters. 162.4 Section 162.4 Customs... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Inspection, Examination, and Search § 162.4 Search for letters. A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary...

  13. 19 CFR 162.4 - Search for letters.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Search for letters. 162.4 Section 162.4 Customs... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Inspection, Examination, and Search § 162.4 Search for letters. A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary...

  14. 19 CFR 162.4 - Search for letters.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Search for letters. 162.4 Section 162.4 Customs... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Inspection, Examination, and Search § 162.4 Search for letters. A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary...

  15. 19 CFR 162.4 - Search for letters.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Search for letters. 162.4 Section 162.4 Customs... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Inspection, Examination, and Search § 162.4 Search for letters. A Customs officer may search vessels for letters which may be on board or may have been conveyed contrary...

  16. 46 CFR 169.219 - Renewal of letter of designation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Renewal of letter of designation. 169.219 Section 169.219 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.219 Renewal of letter of designation....

  17. 46 CFR 169.219 - Renewal of letter of designation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Renewal of letter of designation. 169.219 Section 169.219 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.219 Renewal of letter of designation....

  18. 46 CFR 169.219 - Renewal of letter of designation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Renewal of letter of designation. 169.219 Section 169.219 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.219 Renewal of letter of designation....

  19. 46 CFR 169.219 - Renewal of letter of designation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Renewal of letter of designation. 169.219 Section 169.219 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.219 Renewal of letter of designation....

  20. 46 CFR 169.219 - Renewal of letter of designation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Renewal of letter of designation. 169.219 Section 169.219 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Letter of Designation § 169.219 Renewal of letter of designation....

  1. Student Teacher Letters of Reference: A Critical Analysis

    ERIC Educational Resources Information Center

    Mason, Richard W.; Schroeder, Mark P.

    2012-01-01

    Letters of reference are commonly used in acquiring a job in education. Despite serious issues of validity and reliability in writing and evaluating letters, there is a dearth of research that systematically examines the evaluation process and defines the constructs that define high quality letters. The current study used NVivo to examine 160…

  2. 22 CFR 92.54 - “Letters rogatory” defined.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false âLetters rogatoryâ defined. 92.54 Section 92.54 Foreign Relations DEPARTMENT OF STATE LEGAL AND RELATED SERVICES NOTARIAL AND RELATED SERVICES Depositions and Letters Rogatory § 92.54 “Letters rogatory” defined. In its broader sense in...

  3. Exploring Corporate Rhetoric: Metadiscourse in the CEO's Letter.

    ERIC Educational Resources Information Center

    Hyland, Ken

    1998-01-01

    Examines how metadiscourse is used to create a positive corporate image in 137 CEOs' letters, showing how CEOs use nonpropositional material to realize rational, credible, and affective appeals. Reveals the essentially rhetorical nature of CEOs' letters by comparing the frequency and distribution of metadiscourse in their letters and directors'…

  4. Letter-Naming Knowledge in Kindergartners: What's Happening?

    ERIC Educational Resources Information Center

    Blanchard, Jay; Logan, John

    1988-01-01

    Tests the statement in "Becoming a Nation of Readers" that kindergartners can name an average of 14 letters. Finds that a more realistic distribution is bi-modal in that most kindergartners know 8 or fewer letters, and only a few can name more than 20 letters. (RS)

  5. Characteristics of Rejection Letters and Their Effects on Job Applicants.

    ERIC Educational Resources Information Center

    Jablin, Fredric M.; Krone, Kathleen

    1984-01-01

    Describes the structural and content characteristics of actual employment rejection letters (sent following job screening interviews) and analyzes their impact on applicants' feelings about themselves and about the letters. Concludes that few of the letter characteristics affected applicants' feelings about themselves, but that a number were…

  6. 46 CFR 78.12-1 - Posting of stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Posting of stability letter. 78.12-1 Section 78.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Stability Information § 78.12-1 Posting of stability letter. If a stability letter is issued under § 170.120 of...

  7. 46 CFR 78.12-1 - Posting of stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Posting of stability letter. 78.12-1 Section 78.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Stability Information § 78.12-1 Posting of stability letter. If a stability letter is issued under § 170.120 of...

  8. 46 CFR 35.08-1 - Posting of stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Posting of stability letter. 35.08-1 Section 35.08-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Stability Information § 35.08-1 Posting of stability letter. If a stability letter is issued under § 170.120 of this chapter,...

  9. 46 CFR 35.08-1 - Posting of stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Posting of stability letter. 35.08-1 Section 35.08-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Stability Information § 35.08-1 Posting of stability letter. If a stability letter is issued under § 170.120 of this chapter,...

  10. 46 CFR 131.930 - Display of stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Display of stability letter. 131.930 Section 131.930 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.930 Display of stability letter. If the Coast Guard issues a stability letter under §...

  11. 46 CFR 78.12-1 - Posting of stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Posting of stability letter. 78.12-1 Section 78.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Stability Information § 78.12-1 Posting of stability letter. If a stability letter is issued under § 170.120 of...

  12. 46 CFR 78.12-1 - Posting of stability letter.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Posting of stability letter. 78.12-1 Section 78.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Stability Information § 78.12-1 Posting of stability letter. If a stability letter is issued under § 170.120 of...

  13. 46 CFR 131.930 - Display of stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Display of stability letter. 131.930 Section 131.930 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.930 Display of stability letter. If the Coast Guard issues a stability letter under §...

  14. 46 CFR 131.930 - Display of stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Display of stability letter. 131.930 Section 131.930 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.930 Display of stability letter. If the Coast Guard issues a stability letter under §...

  15. 46 CFR 131.930 - Display of stability letter.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Display of stability letter. 131.930 Section 131.930 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.930 Display of stability letter. If the Coast Guard issues a stability letter under §...

  16. 46 CFR 35.08-1 - Posting of stability letter.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Posting of stability letter. 35.08-1 Section 35.08-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Stability Information § 35.08-1 Posting of stability letter. If a stability letter is issued under § 170.120 of this chapter,...

  17. 46 CFR 35.08-1 - Posting of stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Posting of stability letter. 35.08-1 Section 35.08-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Stability Information § 35.08-1 Posting of stability letter. If a stability letter is issued under § 170.120 of this chapter,...

  18. 46 CFR 131.930 - Display of stability letter.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Display of stability letter. 131.930 Section 131.930 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS OPERATIONS Miscellaneous § 131.930 Display of stability letter. If the Coast Guard issues a stability letter under §...

  19. 50 CFR 216.258 - Renewal of Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in the Gulf of Mexico § 216.258 Renewal of Letters of Authorization. (a) A Letter of Authorization... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Renewal of Letters of Authorization. 216... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING...

  20. 50 CFR 216.257 - Letters of Authorization.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... MAMMALS Taking Marine Mammals Incidental to Conducting Precision Strike Weapon Missions in the Gulf of Mexico § 216.257 Letters of Authorization. (a) A Letter of Authorization, unless suspended or revoked... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Letters of Authorization. 216.257...

  1. 46 CFR 35.08-1 - Posting of stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Posting of stability letter. 35.08-1 Section 35.08-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS OPERATIONS Stability Information § 35.08-1 Posting of stability letter. If a stability letter is issued under § 170.120 of this chapter,...

  2. 46 CFR 78.12-1 - Posting of stability letter.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Posting of stability letter. 78.12-1 Section 78.12-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS OPERATIONS Stability Information § 78.12-1 Posting of stability letter. If a stability letter is issued under § 170.120 of...

  3. 33 CFR 181.17 - Label numbers and letters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Label numbers and letters. 181.17...) BOATING SAFETY MANUFACTURER REQUIREMENTS Manufacturer Certification of Compliance § 181.17 Label numbers and letters. Letters and numbers on each label must: (a) Be no less than one-eighth of an inch...

  4. Cortical Correspondence with Probabilistic Fiber Connectivity

    PubMed Central

    Oguz, Ipek; Niethammer, Marc; Cates, Josh; Whitaker, Ross; Fletcher, Thomas; Vachet, Clement; Styner, Martin

    2009-01-01

    This paper presents a novel method of optimizing point-based correspondence among populations of human cortical surfaces by combining structural cues with probabilistic connectivity maps. The proposed method establishes a tradeoff between an even sampling of the cortical surfaces (a low surface entropy) and the similarity of corresponding points across the population (a low ensemble entropy). The similarity metric, however, isn’t constrained to be just spatial proximity, but uses local sulcal depth measurements as well as probabilistic connectivity maps, computed from DWI scans via a stochastic tractography algorithm, to enhance the correspondence definition. We propose a novel method for projecting this fiber connectivity information on the cortical surface, using a surface evolution technique. Our cortical correspondence method does not require a spherical parameterization. Experimental results are presented, showing improved correspondence quality demonstrated by a cortical thickness analysis, as compared to correspondence methods using spatial metrics as the sole correspondence criterion. PMID:19694301

  5. Letter from Seoul: Correspondence from the International Arts Education Symposium and the Asia-Pacific Regional Conference

    ERIC Educational Resources Information Center

    Aprill, Arnold; Schroeder-Yu, Gigi

    2006-01-01

    Arts educator Gigi Schroeder-Yu and Arnold Aprill arrived in Seoul, Korea to participate in the International Arts Education Symposium and in the Asia-Pacific Regional Conference that are part of the wind up for the pitch of the UNESCO World Conference on Arts Education to be held in Lisbon in March 2006. In this article, they reflect on their…

  6. Word Boxes Improve Phonemic Awareness, Letter-Sound Correspondences, and Spelling Skills of At-Risk Kindergartners

    ERIC Educational Resources Information Center

    Keesey, Susan; Konrad, Moira; Joseph, Laurice M.

    2015-01-01

    Early literacy skills are critical for success in school, yet many children fail to obtain these skills in a timely manner leaving them unable to perform at minimal academic expectations. The purpose of this study was to examine the effects of word box instruction, a research-based intervention designed to promote phonemic awareness, on the…

  7. Resource Letter QI-1: Quantum Information

    NASA Astrophysics Data System (ADS)

    Strauch, Frederick W.

    2016-07-01

    This Resource Letter surveys the history and modern developments in the field of quantum information. It is written to guide advanced undergraduates, beginning graduate students, and other new researchers to the theoretical and experimental aspects of this field. The topics covered include quantum states and processes, quantum coding and cryptography, quantum computation, the experimental implementation of quantum information processing, and the role of quantum information in the fundamental properties and foundations of physical theories.

  8. 31 CFR 29.511 - Demand letters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... administrative costs as set forth in 31 CFR part 5, the FCCS, and 31 U.S.C. 3717, including a statement that such... 31 CFR 902.2); and (m) The fact that a timely filing of a request for reconsideration, waiver and/or... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Demand letters. 29.511 Section...

  9. Resource Letter: TE-1: Teaching electronics

    NASA Astrophysics Data System (ADS)

    Henry, Dennis C.

    2002-01-01

    This Resource Letter examines the evolution, roles, and content of courses in electronics in the undergraduate physics curriculum, and provides a guide to resources for faculty teaching such courses. It concludes with a brief section addressing problems of electromagnetic interference in electronic systems, and provides an introduction to the literature and practice of electromagnetic compatibility. I have included textbooks, reference books, articles, collections of laboratory experiments and projects, sources of equipment and parts, software packages, videos, and websites.

  10. An open letter to Magic Johnson.

    PubMed

    Pazin, G J

    1992-01-01

    The last installment in this series dealt with post-test counseling of a person whose HIV test was negative. The plan was to provide counseling for an HIV-infected person in this installment. NBA basketball star Magic Johnson's surprise announcement on November 7, 1991, of his infection with HIV has provided an unexpected opportunity to counsel a well-known person through an "open letter."

  11. The Space-Clamped Hodgkin-Huxley System with Random Synaptic Input: Inhibition of Spiking by Weak Noise and Analysis with Moment Equations.

    PubMed

    Tuckwell, Henry C; Ditlevsen, Susanne

    2016-10-01

    We consider a classical space-clamped Hodgkin-Huxley model neuron stimulated by synaptic excitation and inhibition with conductances represented by Ornstein-Uhlenbeck processes. Using numerical solutions of the stochastic model system obtained by an Euler method, it is found that with excitation only, there is a critical value of the steady-state excitatory conductance for repetitive spiking without noise, and for values of the conductance near the critical value, small noise has a powerfully inhibitory effect. For a given level of inhibition, there is also a critical value of the steady-state excitatory conductance for repetitive firing, and it is demonstrated that noise in either the excitatory or inhibitory processes or both can powerfully inhibit spiking. Furthermore, near the critical value, inverse stochastic resonance was observed when noise was present only in the inhibitory input process. The system of deterministic differential equations for the approximate first- and second-order moments of the model is derived. They are solved using Runge-Kutta methods, and the solutions are compared with the results obtained by simulation for various sets of parameters, including some with conductances obtained by experiment on pyramidal cells of rat prefrontal cortex. The mean and variance obtained from simulation are in good agreement when there is spiking induced by strong stimulation and relatively small noise or when the voltage is fluctuating at subthreshold levels. In the occasional spike mode sometimes exhibited by spinal motoneurons and cortical pyramidal cells, the assumptions underlying the moment equation approach are not satisfied. The simulation results show that noisy synaptic input of either an excitatory or inhibitory character or both may lead to the suppression of firing in neurons operating near a critical point and this has possible implications for cortical networks. Although suppression of firing is corroborated for the system of moment equations

  12. The Space-Clamped Hodgkin-Huxley System with Random Synaptic Input: Inhibition of Spiking by Weak Noise and Analysis with Moment Equations.

    PubMed

    Tuckwell, Henry C; Ditlevsen, Susanne

    2016-10-01

    We consider a classical space-clamped Hodgkin-Huxley model neuron stimulated by synaptic excitation and inhibition with conductances represented by Ornstein-Uhlenbeck processes. Using numerical solutions of the stochastic model system obtained by an Euler method, it is found that with excitation only, there is a critical value of the steady-state excitatory conductance for repetitive spiking without noise, and for values of the conductance near the critical value, small noise has a powerfully inhibitory effect. For a given level of inhibition, there is also a critical value of the steady-state excitatory conductance for repetitive firing, and it is demonstrated that noise in either the excitatory or inhibitory processes or both can powerfully inhibit spiking. Furthermore, near the critical value, inverse stochastic resonance was observed when noise was present only in the inhibitory input process. The system of deterministic differential equations for the approximate first- and second-order moments of the model is derived. They are solved using Runge-Kutta methods, and the solutions are compared with the results obtained by simulation for various sets of parameters, including some with conductances obtained by experiment on pyramidal cells of rat prefrontal cortex. The mean and variance obtained from simulation are in good agreement when there is spiking induced by strong stimulation and relatively small noise or when the voltage is fluctuating at subthreshold levels. In the occasional spike mode sometimes exhibited by spinal motoneurons and cortical pyramidal cells, the assumptions underlying the moment equation approach are not satisfied. The simulation results show that noisy synaptic input of either an excitatory or inhibitory character or both may lead to the suppression of firing in neurons operating near a critical point and this has possible implications for cortical networks. Although suppression of firing is corroborated for the system of moment equations

  13. Neural Correlates of Letter Reversal in Children and Adults

    PubMed Central

    Kalra, Priya; Yee, Debbie; Sinha, Pawan; Gabrieli, John D. E.

    2014-01-01

    Children often make letter reversal errors when first learning to read and write, even for letters whose reversed forms do not appear in normal print. However, the brain basis of such letter reversal in children learning to read is unknown. The present study compared the neuroanatomical correlates (via functional magnetic resonance imaging) and the electrophysiological correlates (via event-related potentials or ERPs) of this phenomenon in children, ages 5–12, relative to young adults. When viewing reversed letters relative to typically oriented letters, adults exhibited widespread occipital, parietal, and temporal lobe activations, including activation in the functionally localized visual word form area (VWFA) in left occipito-temporal cortex. Adults exhibited significantly greater activation than children in all of these regions; children only exhibited such activation in a limited frontal region. Similarly, on the P1 and N170 ERP components, adults exhibited significantly greater differences between typical and reversed letters than children, who failed to exhibit significant differences between typical and reversed letters. These findings indicate that adults distinguish typical and reversed letters in the early stages of specialized brain processing of print, but that children do not recognize this distinction during the early stages of processing. Specialized brain processes responsible for early stages of letter perception that distinguish between typical and reversed letters may develop slowly and remain immature even in older children who no longer produce letter reversals in their writing. PMID:24859328

  14. 45 CFR 170.405 - Correspondence.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Temporary Certification Program for HIT § 170.405 Correspondence....

  15. 45 CFR 170.405 - Correspondence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Temporary Certification Program for HIT § 170.405 Correspondence....

  16. 45 CFR 170.405 - Correspondence.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Temporary Certification Program for HIT § 170.405 Correspondence....

  17. 45 CFR 170.505 - Correspondence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY ONC HIT Certification Program § 170.505 Correspondence....

  18. 45 CFR 170.505 - Correspondence.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Permanent Certification Program for HIT § 170.505 Correspondence....

  19. 45 CFR 170.505 - Correspondence.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY ONC HIT Certification Program § 170.505 Correspondence....

  20. 45 CFR 170.405 - Correspondence.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Temporary Certification Program for HIT § 170.405 Correspondence....

  1. 45 CFR 170.505 - Correspondence.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... TECHNOLOGY STANDARDS, IMPLEMENTATION SPECIFICATIONS, AND CERTIFICATION CRITERIA AND CERTIFICATION PROGRAMS FOR HEALTH INFORMATION TECHNOLOGY Permanent Certification Program for HIT § 170.505 Correspondence....

  2. Learning of Letter Names and Sounds and Their Contribution to Word Recognition

    ERIC Educational Resources Information Center

    Levin, Iris; Shatil-Carmon, Sivan; Asif-Rave, Ornit

    2006-01-01

    This study investigated knowledge of letter names and letter sounds, their learning, and their contributions to word recognition. Of 123 preschoolers examined on letter knowledge, 65 underwent training on both letter names and letter sounds in a counterbalanced order. Prior to training, children were more advanced in associating letters with their…

  3. [Goethe's own testimony about his involvement with "organic Nature." III. Letters (1818-1832)].

    PubMed

    Voss, H

    1979-01-01

    This third and last extract from GOETHE's letters between 1818 and 1832 follows the Sophien-Ausgabe of Weimar with the exception of the last two remarks which were drawn from other sources. In 1818, GOETHE riched the 69th year of his life. In this late life-time, he corresponded with scientists, literati, musicians, his son, and his grand-duke CARL AUGUST. The subjects of his correspondence are problems of the scientific investigations' organization as well as of true science, predominantly of paleontology and general morphology including the comparative anatomy.

  4. Designability and cooperative folding in a four-letter hydrophobic-polar model of proteins

    NASA Astrophysics Data System (ADS)

    Liu, Hai-Guang; Tang, Lei-Han

    2006-11-01

    The two-letter hydrophobic-polar (HP) model of Lau and Dill [Macromolecules 22, 3986 (1989)] has been widely used in theoretical studies of protein folding due to its conceptual and computational simplicity. Despite its success in elucidating various aspects of the sequence-structure relationship, thermodynamic behavior of the model is not in agreement with a sharp two-state folding transition of many single-domain proteins. To gain a better understanding of this discrepancy, we consider an extension of the HP model by including an “antiferromagnetic” (AF) interaction in the contact potential that favors amino acid residues with complementary attributes. With an enlarged four-letter alphabet, the density of states on the low energy side can be significantly decreased. Computational studies of the four-letter HP model are performed on 36-mer sequences on a square lattice. It is found that the designability of folded structures in the extended model exhibits strong correlation with that of the two-letter HP model, while the AF interaction alone selects a very different class of structures that resembles the Greek key motif for beta sheets. A procedure is introduced to select sequences which have the largest energy gap to the native state. Based on density of states and specific heat calculations in the full configuration space, we show that the optimized sequence is able to fold nearly as cooperatively as a corresponding Gō model.

  5. 12 CFR 7.5007 - Correspondent services.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Correspondent services. 7.5007 Section 7.5007 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY BANK ACTIVITIES AND OPERATIONS Electronic Activities § 7.5007 Correspondent services. It is part of the business of banking for a national bank to offer as a...

  6. 48 CFR 852.236-76 - Correspondence.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 5 2014-10-01 2014-10-01 false Correspondence. 852.236-76 Section 852.236-76 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 852.236-76 Correspondence....

  7. Computer Networking with the Victorian Correspondence School.

    ERIC Educational Resources Information Center

    Conboy, Ian

    During 1985 the Education Department installed two-way radios in 44 remote secondary schools in Victoria, Australia, to improve turn-around time for correspondence assignments. Subsequently, teacher supervisors at Melbourne's Correspondence School sought ways to further augument audio interactivity with computer networking. Computer equipment was…

  8. 45 CFR 170.405 - Correspondence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH INFORMATION TECHNOLOGY HEALTH INFORMATION... FOR HEALTH INFORMATION TECHNOLOGY Temporary Certification Program for HIT § 170.405 Correspondence. (a) Correspondence and communication with the National Coordinator shall be conducted by e-mail, unless...

  9. 48 CFR 42.401 - Contract correspondence.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... administration office (CAO) to the contractor and (2) provide a copy for the CAO's file. When urgency requires sending such correspondence directly to the contractor, a copy shall be sent concurrently to the CAO. (b) The CAO shall send the contracting office a copy of pertinent correspondence conducted between the...

  10. 32 CFR 845.11 - Correspondence.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Correspondence. 845.11 Section 845.11 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE CLAIMS AND LITIGATION COUNSEL FEES AND OTHER EXPENSES IN FOREIGN TRIBUNALS § 845.11 Correspondence. Judge advocates who advise...

  11. Visualising nursing data using correspondence analysis.

    PubMed

    Kokol, Peter; Vošner, Helena Blažun; Železnik, Danica

    2016-09-01

    Background Digitally stored, large healthcare datasets enable nurses to use 'big data' techniques and tools in nursing research. Big data is complex and multi-dimensional, so visualisation may be a preferable approach to analyse and understand it. Aim To demonstrate the use of visualisation of big data in a technique called correspondence analysis. Discussion In the authors' study, relations among data in a nursing dataset were shown visually in graphs using correspondence analysis. The case presented demonstrates that correspondence analysis is easy to use, shows relations between data visually in a form that is simple to interpret, and can reveal hidden associations between data. Conclusion Correspondence analysis supports the discovery of new knowledge. Implications for practice Knowledge obtained using correspondence analysis can be transferred immediately into practice or used to foster further research. PMID:27641707

  12. Visualising nursing data using correspondence analysis.

    PubMed

    Kokol, Peter; Vošner, Helena Blažun; Železnik, Danica

    2016-09-01

    Background Digitally stored, large healthcare datasets enable nurses to use 'big data' techniques and tools in nursing research. Big data is complex and multi-dimensional, so visualisation may be a preferable approach to analyse and understand it. Aim To demonstrate the use of visualisation of big data in a technique called correspondence analysis. Discussion In the authors' study, relations among data in a nursing dataset were shown visually in graphs using correspondence analysis. The case presented demonstrates that correspondence analysis is easy to use, shows relations between data visually in a form that is simple to interpret, and can reveal hidden associations between data. Conclusion Correspondence analysis supports the discovery of new knowledge. Implications for practice Knowledge obtained using correspondence analysis can be transferred immediately into practice or used to foster further research.

  13. The correspondence between Winkler and Monakow during World War I.

    PubMed

    Koehler, Peter J; Jagella, Caroline

    2015-01-01

    The correspondence (1907-1930) between two leading European neurologists, Cornelis Winkler (1855-1941) and Constantin von Monakow (1853-1930), has been preserved in Amsterdam and Zurich. For this paper, letters exchanged during World War I were studied. Professional as well as personal issues were discussed. An international neurology meeting in Berne in September 1914 had to be cancelled due to the war. They hoped that (neuro)scientists would remain politically neutral, continue scientific cooperation, and even be able to influence the course of the war. Winkler and Monakow tried to continue their work on the International Brain Atlas. Although living in neutral countries (The Netherlands and Switzerland), they observed that their practice and scientific work suffered from war conditions. While Winkler continued his activities as a neurologist, Monakow, affected emotionally, experienced a change in scientific interest toward psychoneurology. He used his diaschisis concept, originally an explanation for transient phenomena in stroke, as a metaphor for the social and cultural effects of the war. He directly related cultural development and brain science, bringing in his own emotions, which resulted in the first of several publications on the relations between biology, brain science, and culture.

  14. The correspondence between Winkler and Monakow during World War I.

    PubMed

    Koehler, Peter J; Jagella, Caroline

    2015-01-01

    The correspondence (1907-1930) between two leading European neurologists, Cornelis Winkler (1855-1941) and Constantin von Monakow (1853-1930), has been preserved in Amsterdam and Zurich. For this paper, letters exchanged during World War I were studied. Professional as well as personal issues were discussed. An international neurology meeting in Berne in September 1914 had to be cancelled due to the war. They hoped that (neuro)scientists would remain politically neutral, continue scientific cooperation, and even be able to influence the course of the war. Winkler and Monakow tried to continue their work on the International Brain Atlas. Although living in neutral countries (The Netherlands and Switzerland), they observed that their practice and scientific work suffered from war conditions. While Winkler continued his activities as a neurologist, Monakow, affected emotionally, experienced a change in scientific interest toward psychoneurology. He used his diaschisis concept, originally an explanation for transient phenomena in stroke, as a metaphor for the social and cultural effects of the war. He directly related cultural development and brain science, bringing in his own emotions, which resulted in the first of several publications on the relations between biology, brain science, and culture. PMID:25402843

  15. Effect of letter spacing on visual span and reading speed.

    PubMed

    Yu, Deyue; Cheung, Sing-Hang; Legge, Gordon E; Chung, Susana T L

    2007-01-01

    S. T. L. Chung (2002) has shown that rapid serial visual presentation (RSVP) reading speed varies with letter spacing, peaking near the standard letter spacing for text and decreasing for both smaller and larger spacings. In this study, we tested the hypothesis that the dependence of reading speed on letter spacing is mediated by the size of the visual span-the number of letters recognized with high accuracy without moving the eyes. If so, the size of the visual span and reading speed should show a similar dependence on letter spacing. We tested this prediction for RSVP reading and asked whether it generalizes to the reading of blocks of text requiring eye movements. We measured visual-span profiles and reading speeds as a function of letter spacing. Visual-span profiles, measured with trigrams (strings of three random letters), are plots of letter-recognition accuracy as a function of letter position left or right of fixation. Size of the visual span was quantified by a measure of the area under the visual-span profile. Reading performance was measured using two presentation methods: RSVP and flashcard (a short block of text on four lines). We found that the size of the visual span and the reading speeds measured by the two presentation methods showed a qualitatively similar dependence on letter spacing and that they were highly correlated. These results are consistent with the view that the size of the visual span is a primary visual factor that limits reading speed.

  16. The overlap model: a model of letter position coding.

    PubMed

    Gomez, Pablo; Ratcliff, Roger; Perea, Manuel

    2008-07-01

    Recent research has shown that letter identity and letter position are not integral perceptual dimensions (e.g., jugde primes judge in word-recognition experiments). Most comprehensive computational models of visual word recognition (e.g., the interactive activation model, J. L. McClelland & D. E. Rumelhart, 1981, and its successors) assume that the position of each letter within a word is perfectly encoded. Thus, these models are unable to explain the presence of effects of letter transposition (trial-trail), letter migration (beard-bread), repeated letters (moose-mouse), or subset/superset effects (faulty-faculty). The authors extend R. Ratcliff's (1981) theory of order relations for encoding of letter positions and show that the model can successfully deal with these effects. The basic assumption is that letters in the visual stimulus have distributions over positions so that the representation of one letter will extend into adjacent letter positions. To test the model, the authors conducted a series of forced-choice perceptual identification experiments. The overlap model produced very good fits to the empirical data, and even a simplified 2-parameter model was capable of producing fits for 104 observed data points with a correlation coefficient of .91.

  17. The Overlap Model: A Model of Letter Position Coding

    PubMed Central

    Ratcliff, Roger; Perea, Manuel

    2008-01-01

    Recent research has shown that letter identity and letter position are not integral perceptual dimensions (e.g., jugde primes judge in word-recognition experiments). Most comprehensive computational models of visual word recognition (e.g., the interactive activation model, J. L. McClelland & D. E. Rumelhart, 1981, and its successors) assume that the position of each letter within a word is perfectly encoded. Thus, these models are unable to explain the presence of effects of letter transposition (trial-trail), letter migration (beard-bread), repeated letters (moose-mouse), or subset/superset effects (faulty-faculty). The authors extend R. Ratcliff's (1981) theory of order relations for encoding of letter positions and show that the model can successfully deal with these effects. The basic assumption is that letters in the visual stimulus have distributions over positions so that the representation of one letter will extend into adjacent letter positions. To test the model, the authors conducted a series of forced-choice perceptual identification experiments. The overlap model produced very good fits to the empirical data, and even a simplified 2-parameter model was capable of producing fits for 104 observed data points with a correlation coefficient of .91. PMID:18729592

  18. Algoritmi matematici nelle lettere di Gerbert

    NASA Astrophysics Data System (ADS)

    Rossi, P.

    The content of Gerbert's "scientific" letters is analyzed in detail, with special emphasis on arithmetical and geometrical issues, such as multiplication and division rules related to the use of abacus, superparticular numbers and evaluation of the area of an equilateral triangle. It is shown that Gerbert's area formula, albeit based on rational fractions, could hardly be conceived without knowledge of Pythagoras' theorem. This fact casts a light also on the astronomical tools created by Gerbert, where the didactical aspect cannot be separated from the accuracy of the demonstrations and of the measurements.

  19. The AdS/CFT correspondence

    NASA Astrophysics Data System (ADS)

    Hubeny, Veronika E.

    2015-06-01

    We give a brief review of the AdS/CFT correspondence, which posits the equivalence between a certain gravitational theory and a lower-dimensional non-gravitational one. This remarkable duality, formulated in 1997, has sparked a vigorous research program that has gained in breadth over the years, with applications to many aspects of theoretical (and even experimental) physics, not least to general relativity and quantum gravity. To put the AdS/CFT correspondence into historical context, we start by reviewing the relevant aspects of string theory (of which no prior knowledge is assumed). We then develop the statement of the correspondence, and explain how the two sides of the duality map into each other. Finally, we discuss the implications and applications of the correspondence, and indicate some of the current trends in this subject. The presentation attempts to convey the main concepts in a simple and self-contained manner, relegating supplementary remarks to footnotes.

  20. 48 CFR 871.210 - Correspondence courses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... DEPARTMENT SUPPLEMENTARY REGULATIONS LOAN GUARANTY AND VOCATIONAL REHABILITATION AND EMPLOYMENT PROGRAMS Vocational Rehabilitation and Employment Service 871.210 Correspondence courses. Contracts with institutions...) Trainees must be provided with prompt and adequate lessons service and, unless otherwise specified in...

  1. 48 CFR 871.210 - Correspondence courses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... DEPARTMENT SUPPLEMENTARY REGULATIONS LOAN GUARANTY AND VOCATIONAL REHABILITATION AND EMPLOYMENT PROGRAMS Vocational Rehabilitation and Employment Service 871.210 Correspondence courses. Contracts with institutions...) Trainees must be provided with prompt and adequate lessons service and, unless otherwise specified in...

  2. Letter to the editor of TAAP, in response to letter from Anders et al.

    EPA Science Inventory

    To the Editor, Toxicology and Applied Pharmacology: We would like to address the letter to the editor submitted by Anders et al. regarding the substantive issues raised regarding our paper "Evaluation of two different metabolic hypotheses for dichloromethane toxicity using physi...

  3. ERP correlates of letter identity and letter position are modulated by lexical frequency

    PubMed Central

    Vergara-Martínez, Marta; Perea, Manuel; Gómez, Pablo; Swaab, Tamara Y.

    2013-01-01

    The encoding of letter position is a key aspect in all recently proposed models of visual-word recognition. We analyzed the impact of lexical frequency on letter position assignment by examining the temporal dynamics of lexical activation induced by pseudowords extracted from words of different frequencies. For each word (e.g., BRIDGE), we created two pseudowords: A transposed-letter (TL: BRIGDE) and a replaced-letter pseudoword (RL: BRITGE). ERPs were recorded while participants read words and pseudowords in two tasks: Semantic categorization (Experiment 1) and lexical decision (Experiment 2). For high-frequency stimuli, similar ERPs were obtained for words and TL-pseudowords, but the N400 component to words was reduced relative to RL-pseudowords, indicating less lexical/semantic activation. In contrast, TL- and RL-pseudowords created from low-frequency stimuli elicited similar ERPs. Behavioral responses in the lexical decision task paralleled this asymmetry. The present findings impose constraints on computational and neural models of visual-word recognition. PMID:23454070

  4. A crowdful of letters: disentangling the role of similarity, eccentricity and spatial frequencies in letter crowding.

    PubMed

    Zahabi, Sacha; Arguin, Martin

    2014-04-01

    The present study investigated the joint impact of target-flanker similarity and of spatial frequency content on the crowding effect in letter identification. We presented spatial frequency filtered letters to neurologically intact non-dyslexic readers while manipulating target-flanker distance, target eccentricity and target-flanker confusability (letter similarity metric based on published letter confusion matrices). The results show that high target-flanker confusability magnifies crowding. They also reveal an intricate pattern of interactions of the spatial frequency content of the stimuli with target eccentricity, flanker distance and similarity. The findings are congruent with the notion that crowding results from the inappropriate pooling of target and flanker features and that this integration is more likely to match a response template at a subsequent decision stage with similar than dissimilar flankers. In addition, the evidence suggests that crowding from similar flankers is biased towards relatively high spatial frequencies and that crowding shifts towards lower spatial frequencies as target eccentricity is increased.

  5. The Continuity of American Letters in "The Scarlet Letter" and "The Beast in the Jungle."

    ERIC Educational Resources Information Center

    Gottschalk, Jane

    1967-01-01

    Fictional works, of different literary periods, which share a common perception of man can be explicated and compared with each other to illustrate a continuing tradition in American literature. Such a basis for comparison exists between Hawthorne's romance, "The Scarlet Letter," which appeared in 1850, and Henry James' fantasy, "The Beast in the…

  6. Vocational Power Letters. Step-by-Step Procedures in Writing a Letter to a Legislator.

    ERIC Educational Resources Information Center

    Palladino, Dolores

    This packet for vocational educators contains information and materials on writing a letter to a state legislator. A step-by-step procedure is outlined and informative materials that expand upon the various steps are then provided. These materials include a sample Mailgram, a flowchart on how an idea becomes a state law, common sense rules for…

  7. An early electrophysiological response associated with expertise in letter perception.

    PubMed

    Wong, Alan C N; Gauthier, Isabel; Woroch, Brion; DeBuse, Casey; Curran, Tim

    2005-09-01

    Expertise with print is likely to optimize visual processes for recognizing characters of a familiar writing system. Although brain activations have been identified for words and letter strings in contrast with other stimuli, relatively little work has focused on the neural basis of single-letter perception. English readers and Chinese-English bilinguals participated in an ERP study and performed a 1-back identity judgment on Roman letters, Chinese characters, pseudofonts, and their string versions. The Chinese-English bilinguals showed an enhanced N170 for both Roman letters and Chinese characters relative to pseudofonts. For the non-Chinese readers, the N170 amplitude was larger for Roman letters relative to Chinese characters and pseudofonts. Our results suggest that changes in relatively early visual processes underlie expert letter perception.

  8. Letter report: Cold crucible melter assessment

    SciTech Connect

    Elliott, M.L.

    1996-03-01

    One of the activities of the PNL Vitrification Technology Development (PVTD) Project is to assist the Tank Waste Remediation Systems (TWRS) Program in determining which melter systems should be performance tested for potential implementation in the high-level waste (HLW) vitrification plant. The Richland Operations Office (RL) has recommended that the Cold Crucible Melter (CCM) be evaluated as a candidate ``next generation`` melter. As a result, the CCM System Evaluation cost account was established under the PVTD Project so that the CCM could be initially assessed on a high-priority basis. This letter report summarizes a brief initial review and assessment of the CCM. Using the recommendations made in this document, Westinghouse Hanford Company (WHC) and RL will make a decision regarding the urgency of performance testing the CCM. If the decision is favorable, a subcontract will be negotiated for performance testing of a CCM using Hanford HLW simulants in a pilot-scale facility. Because of the aggressive nature of the schedule, the CCM evaluation was not rigorous. The evaluation consisted of a literature review and interviews with proponents of the technology during a recent trip to France. This letter report summarizes the evaluation and makes recommendations regarding further work in this area.

  9. Dissociation of reading strategies: letter-by-letter reading in the native language and normal reading in the learned language. A case study.

    PubMed

    Kremin, H; Chomel-Guillaume, S; Ferrand, I; Bakchine, S

    2000-01-01

    In letter-by-letter reading, which is typically observed in Dejerine's (1892) "pure alexia," oral reading seems to be mediated by the naming of the constituent letters of the printed sequence: reading time rises abnormally as a function of the number of letters of the target item. We describe a patient with fluent aphasia who showed the unusual pattern of letter-by-letter reading together with surface dyslexia in her native language (French) and apparently normal reading in the second, learned language (English). Thus, letter-by-letter reading should be considered as a description of a symptom rather than the consequence of a unique type of functional impairment.

  10. Insights from letter position dyslexia on morphological decomposition in reading.

    PubMed

    Friedmann, Naama; Gvion, Aviah; Nisim, Roni

    2015-01-01

    We explored morphological decomposition in reading, the locus in the reading process in which it takes place and its nature, comparing different types of morphemes. We assessed these questions through the analysis of letter position errors in readers with letter position dyslexia (LPD). LPD is a selective impairment to letter position encoding in the early stage of word reading, which results in letter migrations (such as reading "cloud" for "could"). We used the fact that migrations in LPD occur mainly in word-interior letters, whereas exterior letters rarely migrate. The rationale was that if morphological decomposition occurs prior to letter position encoding and strips off affixes, word-interior letters adjacent to an affix (e.g., signs-signs) would become exterior following affix-stripping and hence exhibit fewer migrations. We tested 11 Hebrew readers with developmental LPD and 1 with acquired LPD in 6 experiments of reading aloud, lexical decision, and comprehension, at the single word and sentence levels (compared with 25 age-matched control participants). The LPD participants read a total of 12,496 migratable words. We examined migrations next to inflectional, derivational, or bound function morphemes compared with migrations of exterior letters. The results were that root letters adjacent to inflectional and derivational morphemes were treated like middle letters, and migrated frequently, whereas root letters adjacent to bound function morphemes patterned with exterior letters, and almost never migrated. Given that LPD is a pre-lexical deficit, these results indicate that morphological decomposition takes place in an early, pre-lexical stage. The finding that morphologically complex nonwords showed the same patterns indicates that this decomposition is structurally, rather than lexically, driven. We suggest that letter position encoding takes place before morphological analysis, but in some cases, as with bound function morphemes, the complex word is re

  11. Insights from letter position dyslexia on morphological decomposition in reading.

    PubMed

    Friedmann, Naama; Gvion, Aviah; Nisim, Roni

    2015-01-01

    We explored morphological decomposition in reading, the locus in the reading process in which it takes place and its nature, comparing different types of morphemes. We assessed these questions through the analysis of letter position errors in readers with letter position dyslexia (LPD). LPD is a selective impairment to letter position encoding in the early stage of word reading, which results in letter migrations (such as reading "cloud" for "could"). We used the fact that migrations in LPD occur mainly in word-interior letters, whereas exterior letters rarely migrate. The rationale was that if morphological decomposition occurs prior to letter position encoding and strips off affixes, word-interior letters adjacent to an affix (e.g., signs-signs) would become exterior following affix-stripping and hence exhibit fewer migrations. We tested 11 Hebrew readers with developmental LPD and 1 with acquired LPD in 6 experiments of reading aloud, lexical decision, and comprehension, at the single word and sentence levels (compared with 25 age-matched control participants). The LPD participants read a total of 12,496 migratable words. We examined migrations next to inflectional, derivational, or bound function morphemes compared with migrations of exterior letters. The results were that root letters adjacent to inflectional and derivational morphemes were treated like middle letters, and migrated frequently, whereas root letters adjacent to bound function morphemes patterned with exterior letters, and almost never migrated. Given that LPD is a pre-lexical deficit, these results indicate that morphological decomposition takes place in an early, pre-lexical stage. The finding that morphologically complex nonwords showed the same patterns indicates that this decomposition is structurally, rather than lexically, driven. We suggest that letter position encoding takes place before morphological analysis, but in some cases, as with bound function morphemes, the complex word is re

  12. Preliminary letter identification in the perception of words and nonwords.

    PubMed

    McClelland, J L

    1976-02-01

    Words with mixed uppercase and lowercase letters (e.g. fAdE) were perceived more accurately than mixed-case pseudowords (e.g. gAdE), and mixed-case pseudowords were perceived more accurately than mixed-case unrelated letter strings (e.g. eFdT). In addition, same-case words were perceived more accurately than their mixed-case counterparts. The same held true for pseudowords but not for unrelated letter strings. The results are compatible with the view that both letter identify and visual form information are used in word perception.

  13. Insights from letter position dyslexia on morphological decomposition in reading

    PubMed Central

    Friedmann, Naama; Gvion, Aviah; Nisim, Roni

    2015-01-01

    We explored morphological decomposition in reading, the locus in the reading process in which it takes place and its nature, comparing different types of morphemes. We assessed these questions through the analysis of letter position errors in readers with letter position dyslexia (LPD). LPD is a selective impairment to letter position encoding in the early stage of word reading, which results in letter migrations (such as reading “cloud” for “could”). We used the fact that migrations in LPD occur mainly in word-interior letters, whereas exterior letters rarely migrate. The rationale was that if morphological decomposition occurs prior to letter position encoding and strips off affixes, word-interior letters adjacent to an affix (e.g., signs-signs) would become exterior following affix-stripping and hence exhibit fewer migrations. We tested 11 Hebrew readers with developmental LPD and 1 with acquired LPD in 6 experiments of reading aloud, lexical decision, and comprehension, at the single word and sentence levels (compared with 25 age-matched control participants). The LPD participants read a total of 12,496 migratable words. We examined migrations next to inflectional, derivational, or bound function morphemes compared with migrations of exterior letters. The results were that root letters adjacent to inflectional and derivational morphemes were treated like middle letters, and migrated frequently, whereas root letters adjacent to bound function morphemes patterned with exterior letters, and almost never migrated. Given that LPD is a pre-lexical deficit, these results indicate that morphological decomposition takes place in an early, pre-lexical stage. The finding that morphologically complex nonwords showed the same patterns indicates that this decomposition is structurally, rather than lexically, driven. We suggest that letter position encoding takes place before morphological analysis, but in some cases, as with bound function morphemes, the complex word

  14. 50 CFR 216.256 - Applications for Letters of Authorization.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS REGULATIONS GOVERNING THE TAKING AND... in the Gulf of Mexico § 216.256 Applications for Letters of Authorization. To incidentally...

  15. Charles Darwin and other great men in correspondence with Carl Wilhelm von Naegeli.

    PubMed

    Naegeli, W; Wiedemann, H R

    1993-04-15

    The great Swiss-German botanist Carl Wilhelm von Naegeli (1817-1891) was a student of Lorenz Oken, A.P. de Candolle, and Matthias Jacob Schleiden and became a key figure in "genetic" (i.e., evolutionary-developmental) biology in the mid-late 19th century. He was an expert on the hawk-weed, Hieracium and also made important contributions to microbiology. One of his many outstanding students was Carl Correns, one of the 3 rediscoverers of Mendel's work. Naegeli was an early proponent and defender of Darwin. The correspondence preserved in the Naegeli family contains many important letters between Naegeli and his contemporaries. Those from Mendel to Naegeli have passed out of the Naegeli family and were published by Correns earlier in the century. However, exceptionally notable items still in the archives of the Naegeli family include 4 surviving letters from Darwin, 2 letters from Virchow, and 10 from Justus von Liebig. In spite of a lack of appreciation of Mendel's work, we call attention to the importance of those surviving documents from an era in which very few of the greatest naturalists and founders of modern biology--including Goethe, Darwin, Galton, Agassiz, von Humboldt, von Baer--were without "blind spots."

  16. Charles Darwin and other great men in correspondence with Carl Wilhelm von Naegeli.

    PubMed

    Naegeli, W; Wiedemann, H R

    1993-04-15

    The great Swiss-German botanist Carl Wilhelm von Naegeli (1817-1891) was a student of Lorenz Oken, A.P. de Candolle, and Matthias Jacob Schleiden and became a key figure in "genetic" (i.e., evolutionary-developmental) biology in the mid-late 19th century. He was an expert on the hawk-weed, Hieracium and also made important contributions to microbiology. One of his many outstanding students was Carl Correns, one of the 3 rediscoverers of Mendel's work. Naegeli was an early proponent and defender of Darwin. The correspondence preserved in the Naegeli family contains many important letters between Naegeli and his contemporaries. Those from Mendel to Naegeli have passed out of the Naegeli family and were published by Correns earlier in the century. However, exceptionally notable items still in the archives of the Naegeli family include 4 surviving letters from Darwin, 2 letters from Virchow, and 10 from Justus von Liebig. In spite of a lack of appreciation of Mendel's work, we call attention to the importance of those surviving documents from an era in which very few of the greatest naturalists and founders of modern biology--including Goethe, Darwin, Galton, Agassiz, von Humboldt, von Baer--were without "blind spots." PMID:8484417

  17. Factorization of correspondence and camera error for unconstrained dense correspondence applications

    SciTech Connect

    Knoblauch, D; Hess-Flores, M; Duchaineau, M; Kuester, F

    2009-09-29

    A correspondence and camera error analysis for dense correspondence applications such as structure from motion is introduced. This provides error introspection, opening up the possibility of adaptively and progressively applying more expensive correspondence and camera parameter estimation methods to reduce these errors. The presented algorithm evaluates the given correspondences and camera parameters based on an error generated through simple triangulation. This triangulation is based on the given dense, non-epipolar constraint, correspondences and estimated camera parameters. This provides an error map without requiring any information about the perfect solution or making assumptions about the scene. The resulting error is a combination of correspondence and camera parameter errors. An simple, fast low/high pass filter error factorization is introduced, allowing for the separation of correspondence error and camera error. Further analysis of the resulting error maps is applied to allow efficient iterative improvement of correspondences and cameras.

  18. [Questions and worries. On the correspondence of Grete Bibring and Anna Freud 1949-1975].

    PubMed

    Bakman, Nina

    2015-01-01

    Grete Bibring (1899 - 1977) was a representative of the second generation of analysts. Having emigrated from Vienna to London in 1938, she left for Boston in 1942 where she made a remarkable career. 1946 she became head of the department of psychiatry at the Beth-Israel hospital in Harvard and from 1961 the first woman professor of medicine there. She maintained a connection with European psychoanalysis in the person of Anna Freud with whom she corresponded regularly. Their letters contain an interesting exchange of ideas about psychoanalytic institutions (e.g. the American Psychoanalytical Association) and papers (e.g. on pregnancy). It is also the testimony of an exceptional friendship.

  19. Melvin magnetic fluxtube/cosmology correspondence

    NASA Astrophysics Data System (ADS)

    Kastor, David; Traschen, Jennie

    2015-12-01

    We explore a correspondence between Melvin magnetic fluxtubes and anisotropic cosmological solutions, which we call ‘Melvin cosmologies’. The correspondence via analytic continuation provides useful information in both directions. Solution generating techniques known on the fluxtube side can also be used for generating cosmological backgrounds. Melvin cosmologies interpolate between different limiting Kasner behaviors at early and late times. This has an analogue on the fluxtube side between limiting Levi-Civita behavior at small and large radii. We construct generalized Melvin fluxtubes and cosmologies in both Einstein-Maxwell theory and dilaton gravity and show that similar properties hold.

  20. Analysis of US Food and Drug Administration Warning Letters

    PubMed Central

    Salas, Maribel; Martin, Michelle; Pisu, Maria; McCall, Erin; Zuluaga, Alvaro; Glasser, Stephen P.

    2013-01-01

    Background Recent studies have suggested that there has been an increase in the number of ‘warning letters’ issued by the US Food and Drug Administration (FDA) despite the publication of the FDA advertising guidelines. However, limited information is available on the description of warning letters. The objective of this study was to analyse the frequency and content of FDA warning letters in relation to promotional claims and discuss the influence of regulatory and industry constraints on promotion. Methods All warning letters published by the FDA between 5 May 1995 and 11 June 2007 were reviewed. Warning letters related to promotional issues were included and analysed. Information related to the identification number, date of the warning letter, FDA division that issued the letter, drug name, manufacturer, specific warning problem, type of promotional material and requested action was extracted. Two independent investigators reviewed and classified each PDF file, any differences were discussed until a consensus was reached. Results Between May 1995 and June 2007 a total of 8692 warning letters were issued, of which 25% were related to drugs. Of these, 206 warning letters focused on drug promotion and were included in this study: 23% were issued in 2005, 15% in 2004 and 14% in 1998. In total, 47% of the warning letters were issued because of false or misleading unapproved doses and uses, 27% failed to disclose risks, 15% cited misleading promotion, 8% related to misleading labelling and 3% promoted false effectiveness claims. Discussion There is an important variation in the number of warning letters issued in the last decade, probably because of the increasing number of drugs approved by the FDA, drug withdrawal scandals, and the publication of the FDA and the Pharmaceutical Research and Manufacturers of America (PhRMA) guidelines. Conclusion We found that benefit-related claims, such as unapproved uses or doses of drugs, and failure to disclose risks, are the