Elementary Teachers\u27 Perceptions of Giftedness: An Examination of the Relationship Between Teacher Background and Gifted Identification

Two hundred and eighty-one teachers participated in an online survey which investigated the relationship between teacher background and the use of student characteristics as indicators of giftedness. Teachers’ global perceptions of giftedness as they related to background characteristics were also examined. Nine teacher characteristics were examined and included: educational background, years of teaching experience, gifted education preparation, SES of origin, perceived similarities to students, diversity in classrooms, school locale, Title 1 school status, and percentage of students eligible for the federal free or reduced-price lunch program. A factor analysis was conducted and a four factor solution was derived. The resulting dimensions were: Textbook Indicators, Nonconforming, Teacher Pleasing, and Incongruent characteristics. The mean ratings suggested that teachers were more likely to use Textbook Indicators and Teacher Pleasing characteristics as indicators of giftedness. Gifted education preparation was found to positively correlate to the Nonconforming dimension. Teachers with gifted education training were more likely to use nonconforming characteristics as indicators of giftedness. Years of experience was positively correlated with Nonconforming and Teacher Pleasing dimensions. That is, with more years of experience, teachers were more likely to use Nonconforming and Teacher Pleasing characteristics as indicators of giftedness. Diversity was negatively correlated with the Textbook Indicators. Teachers with less diverse classrooms were more likely to use Textbook Indicators. The percentage of students qualifying for the federal free or reduced-price lunch program was positively correlated with “Giftedness manifests itself differently in different socioeconomic groups.” “Boys are more likely to show their giftedness through activities that tap spatial ability” was positively correlated to the Nonconforming dimension, and to a lesser degree, the Teacher Pleasing dimension. “Girls are more likely to show their giftedness through activities that tap verbal ability” was positively correlated to the Teacher Pleasing dimension. Teachers are encouraged to recognize a wider spectrum of behaviors and characteristics in order to make more inclusive referrals. Teachers should be aware of how culture can influence manifestations of giftedness. Recommendations include professional development that features gifted education training and multicultural education as related to identification of the gifted

The Origination and Diagnostics of Uncaptured Beam in the Tevatron and Its Control by Electron Lenses

In the Collider Run II, the Tevatron operates with 36 high intensity bunches of 980 GeV protons and antiprotons. Particles not captured by the Tevatron RF system pose a threat to quench the superconducting magnet during acceleration or at beam abort. We describe the main mechanisms for the origination of this uncaptured beam, and present measurements of its main parameters by means of a newly developed diagnostics system. The Tevatron Electron Lens is effectively used in the Collider Run II operation to remove uncaptured beam and keep its intensity in the abort gaps at a safe level.Comment: 36 pp, 15 Figs, submitted for publicati5on in Phys. Rev. Special Topics Accel. Beam

An Analog VLSI Saccadic Eye Movement System

In an effort to understand saccadic eye movements and their relation to visual attention and other forms of eye movements, we - in collaboration with a number of other laboratories - are carrying out a large-scale effort to design and build a complete primate oculomotor system using analog CMOS VLSI technology. Using this technology, a low power, compact, multi-chip system has been built which works in real-time using real-world visual inputs. We describe in this paper the performance of an early version of such a system including a 1-D array of photoreceptors mimicking the retina, a circuit computing the mean location of activity representing the superior colliculus, a saccadic burst generator, and a one degree-of-freedom rotational platform which models the dynamic properties of the primate oculomotor plant

Tune-Shift Compensation Using the Tevatron Electron Lens

The Tevatron Electron Lens was originally designed to alleviate the tune shift and spread induced in Tevatron antiproton bunches from interactions with the proton bunches. We report recent developments and successful results of such tune-shift compensation. Lifetime measurements are central to our data and the basis of our analysis. Future goals and possible uses for the lens are also discussed

Exploring Minimal Scenarios to Produce Transversely Bright Electron Beams Using the Eigen-Emittance Concept

Next generation hard X-ray free electron lasers require electron beams with low transverse emittance. One proposal to achieve these low emittances is to exploit the eigen-emittance values of the beam. The eigen-emittances are invariant under linear beam transport and equivalent to the emittances in an uncorrelated beam. If a correlated beam with two small eigen-emittances can be produced, removal of the correlations via appropriate optics will lead to two small emittance values, provided non-linear effects are not too large. We study how such a beam may be produced using minimal linear correlations. We find it is theoretically possible to produce such a beam, however it may be more difficult to realize in practice. We identify linear correlations that may lead to physically realizable emittance schemes and discuss promising future avenues.Comment: 7 pages, 2 figures, to appear in NIM

Computing motion using analog VLSI vision chips: An experimental comparison among different approaches

We have designed, built and tested a number of analog CMOS VLSI circuits for computing 1-D motion from the time-varying intensity values provided by an array of on-chip phototransistors. We present experimental data for two such circuits and discuss their relative performance. One circuit approximates the correlation model while a second chip uses resistive grids to compute zero-crossings to be tracked over time by a separate digital processor. Both circuits integrate image acquisition with image processing functions and compute velocity in real time. For comparison, we also describe the performance of a simple motion algorithm using off-the-shelf digital components. We conclude that analog circuits implementing various correlation-like motion algorithms are more robust than our previous analog circuits implementing gradient-like motion algorithms

Experimental Demonstration of Beam-Beam Compensation by Tevatron Electron Lenses and Prospects for the LHC

Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams are significant sources of beam loss and lifetime limitations in the Tevatron Collider Run II (2001-present). We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in high energy physics (HEP) operation, predict the performance for planned luminosity upgrades and discuss ways to improve it

Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with electron lenses, novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position; we explore the effects of electron-beam imperfections and noises; and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses.Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with electron lenses, novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron beam current, energy and position/ we explore the effects of electron-beam imperfections and noises/ and we quantify the improvements of the high-energy beam intensity and the collider luminosity lifetime obtained by the action of the Tevatron Electron Lenses