1,331 research outputs found

    You Don’t Need to Speak to be Heard: The Effects of Using American Sign Language with Hearing Lower Elementary Montessori Children

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    Our research introduced the use of ASL signs with hearing elementary children and examined if this intervention affected the noise level produced in the classroom. The project was performed in two Montessori lower elementary classrooms (1st-3rd grade); one at a Maine private Montessori school, with 28 hearing children, and one at a Wisconsin public Montessori school, with 34 hearing children. In Wisconsin the researcher was a teacher in the classroom, in Maine the researcher was not. Data was measured using four tools: a decibel measuring app, observation form, tally sheet, and a structured discussion. In both classrooms, the change in noise level was minimal, decreasing by 2% overall. Qualitative results, however, indicate the project was worthwhile. The children responded positively to instructions given using ASL and their enthusiasm of learning signs justified the intervention. The intervention granted the children opportunities to discuss exceptionalities. We recognized the importance in such conversations and encouraged this dialogue. Keywords

    Telomeres, chromosome instability and cancer

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    Telomeres are composed of repetitive G-rich sequence and an abundance of associated proteins that together form a dynamic cap that protects chromosome ends and allows them to be distinguished from deleterious DSBs. Telomere-associated proteins also function to regulate telomerase, the ribonucleoprtotein responsible for addition of the species-specific terminal repeat sequence. Loss of telomere function is an important mechanism for the chromosome instability commonly found in cancer. Dysfunctional telomeres can result either from alterations in the telomere-associated proteins required for end-capping function, or from alterations that promote the gradual or sudden loss of sufficient repeat sequence necessary to maintain proper telomere structure. Regardless of the mechanism, loss of telomere function can result in sister chromatid fusion and prolonged breakage/fusion/bridge (B/F/B) cycles, leading to extensive DNA amplification and large terminal deletions. B/F/B cycles terminate primarily when the unstable chromosome acquires a new telomere, most often by translocation of the ends of other chromosomes, thereby providing a mechanism for transfer of instability from one chromosome to another. Thus, the loss of a single telomere can result in on-going instability, affect multiple chromosomes, and generate many of the types of rearrangements commonly associated with human cancer

    Particle size segregation in granular flow in silos

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    Segregation and layering of alumina in storage silos are investigated, with a view to predicting output quality versus time, given known variations in input quality on emplacement. A variety of experiments were conducted, existing relevant publications were reviewed, and the basis for an algorithm for predicting the effect of withdrawing from a central flowing region, in combination with variations in quality due to geometric, layering and segregation effects, is described in this report

    Constraining fine tuning in composite Higgs models with partially composite leptons

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    Minimal Composite Higgs Models (MCHM) have long provided a solution to the hierarchy problem of the Standard Model, yet suffer from various sources of fine tuning that are becoming increasingly problematic with the lack of new physics observations at the LHC. We develop a new fine tuning measure that accurately counts each contribution to fine tuning (single, double, triple, etc) that can occur in a theory with np parameters, that must reproduce no observables. We then use a novel scanning procedure to perform a comprehensive study of three different two-site, 4D, SO(5) β†’ SO(4) MCHMs with all third generation fermions included, distinguished by the choice of the lepton embeddings. These are the MCHM5β€‰βˆ’β€‰5β€‰βˆ’β€‰55β€‰βˆ’β€‰5β€‰βˆ’β€‰5, MCHM14β€‰βˆ’β€‰14β€‰βˆ’β€‰105β€‰βˆ’β€‰5β€‰βˆ’β€‰5 and MCHM14β€‰βˆ’β€‰1β€‰βˆ’β€‰105β€‰βˆ’β€‰5β€‰βˆ’β€‰5, where MCHMlβ€‰βˆ’β€‰Ο„β€‰βˆ’β€‰Ξ½qβ€‰βˆ’β€‰tβ€‰βˆ’β€‰b has the lepton doublet partner in representation l, tau partner in representation Ο„, and so on. We find that embedding at least one massive lepton in the symmetric 14 of SO(5) moderately reduces the tuning for the case of low top partner masses (in line with previous results), but that this is balanced against the increased complexity of the model when one properly accounts for all sources of fine tuning. We study both the current relative fine-tuning of each scenario, and the future prospects. Noting that the different scenarios behave differently with respect to future improvements in collider measurements, we find that the MCHM14β€‰βˆ’β€‰1β€‰βˆ’β€‰105β€‰βˆ’β€‰5β€‰βˆ’β€‰5 enjoys a relatively low increase in fine tuning even for a future lower bound on the top partner masses of 3.4 TeV (or equivalently a maximum Higgs-fermion or Higgs-gluon coupling deviation of 2%).James Barnard, Daniel Murnane, Martin White, Anthony G. William

    Attosecond time-scale intra-atomic phase matching of high harmonic generation

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    Includes bibliographical references (page 5461).Using a model of high-harmonic generation that couples a fully quantum calculation with a semi-classical electron trajectory picture, we show that a new type of phase matching is possible when an atom is driven by an optimal optical waveform. For an optimized laser pulse shape, strong constructive interference is obtained in the frequency domain between emissions from different electron trajectories, thereby selectively enhancing a particular harmonic order. This work demonstrates that coherent control in the strong-field regime is possible by adjusting the peaks of a laser field on an attosecond time scale

    Adaptive pulse compression for transform-limited 15-fs high-energy pulse generation

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    Includes bibliographical references (page 589).We demonstrate the use of a deformable-mirror pulse shaper, combined with an evolutionary optimization algorithm, to correct high-order residual phase aberrations in a 1-mJ, 1-kHz, 15-fs laser amplifier. Frequency resolved optical gating measurements reveal that the output pulse duration of 15.2 fs is within our measurement error of the theoretical transform limit. This technique significantly reduces the pulse duration and the temporal prepulse energy of the pulse while increasing the peak intensity by 26%. It is demonstrated, for what is believed to be the first time, that the problem of pedestals in laser amplifiers can be addressed by spectral-domain correction

    Absolute determination of the wavelength and spectrum of an extreme-ultraviolet beam by a Young's double-slit measurement

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    Includes bibliographical references (page 709).The interference pattern produced by irradiation of a pair of pinholes with a beam contains information on both the spatial and the temporal coherence properties of the beam, as well as its power spectrum. We demonstrate experimentally for what is believed to be the first time that the spectrum of an extreme-ultraviolet (EUV) beam can be obtained from a measurement of the interference pattern produced by a pinhole pair. This approach offers a convenient method of making absolute wavelength and relative spectral intensity calibrations in the EUV
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