Learners with autism spectrum disorder (ASD) often exhibit difficulty in the area of reading comprehension. Research connecting the learning needs of individuals with ASD, existing effective ...practices, teacher training, and teacher perceptions of their own ability to teach reading comprehension is scarce. Quantitative survey methodology and hierarchical regression analysis were utilized to investigate teacher preparedness to use effective practices, along with the job‐related factors of experience, administrator support, learner verbal ability, and instructional setting, as predictors of (1) teacher perceived self‐efficacy and (2) teacher perceived outcome expectancy teaching reading comprehension to learners with ASD. Study findings, based on 112 teacher participants, indicate that teachers with a higher confidence in using effective practices have both a higher perception of their own ability to teach comprehension (self‐efficacy), and a higher expectation of their own ability to increase instructional outcomes in learners with ASD (outcome expectancy). Implications for practice include professional development recommendations and provision of ongoing support from principals and administrators.
Dihydroxy-acid dehydratase has been purified from Escherichia coli and characterized as a homodimer with a subunit molecular weight of 66,000. The combination of UV visible absorption, EPR, magnetic ...circular dichroism, and resonance Raman spectroscopies indicates that the native enzyme contains a 4Fe-4S2+,+ cluster, in contrast to spinach dihydroxy-acid dehydratase which contains a 2Fe-2S2+,+ cluster (Flint, D. H., and Emptage, M. H. (1988) J. Biol. Chem. 263, 3558-3564). In frozen solution, the reduced 4Fe-4S+ cluster has a S = 3/2 ground state with minor contributions from forms with S = 1/2 and possibly S = 5/2 ground states. Resonance Raman studies of the 4Fe-4S2+ cluster in E. coli dihydroxy-acid dehydratase indicate non-cysteinyl coordination of a specific iron, which suggests that it is likely to be directly involved in catalysis as is the case with aconitase (Emptage, M. H., Kent, T. A., Kennedy, M. C., Beinert, H., and Münck, E. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 4674-4678). Dihydroxy-acid dehydratase from E. coli is inactivated by O2 in vitro and in vivo as a result of oxidative degradation of the 4Fe-4Scluster. Compared to aconitase, the oxidized cluster of E. coli dihydroxy-acid dehydratase appears to be less stable as either a cubic or linear 3Fe-4S cluster or a 2Fe-2S cluster. Oxidative degradation appears to lead to a complete breakdown of the Fe-S cluster, and the resulting protein cannot be reactivated with Fe2+ and thiol reducing agents.
Writing can be used in a variety of communities and for a variety of purposes and is necessary for success in school and the workplace, yet many students, including autistic students, struggle with ...written communication. There is a need to explore how writing it taught to these students.
This pilot study examined how writing is taught to autistic students, specifically, how frequently teachers and students engaged in activities incorporated into writing instruction, training or preparation in teaching writing to their students and whether training influence teachers’ practices, teachers' experiences teaching writing to autistic students, including the most significant challenges and successes the support they need to teach writing to their autistic students. Responses from 35 online surveys completed by teachers of autistic students were analyzed.
Results indicated that teachers of autistic students incorporate a wide range of strategies and practices into their instruction, and that their students write using a variety of genres and products. Nearly half of all respondents received no formal training in teaching writing to autistic students. In terms of supports, the greatest need was for professional development/training on how specifically to support their autistic students
The diversity of responses reflects the heterogeneous nature of autistic students. Teachers should consider the use of EBPs such as visuals and peer support and include student interest in their writing. Furthermore, teacher preparation programs should look to add coursework in writing instruction, with particular attention paid to meeting the diverse strengths and needs of autistic students.
•Teachers use a variety of strategies to teach writing to autistic students, with the greatest number using visual supports•Most teachers do not receive training in how to teach writing to autistic students.•Most respondents indicated the need for professional development/ on how specifically to support autistic students.
Spall response of annealed copper to direct explosive loading
SHOCK COMPRESSION OF CONDENSED MATTER - 2015: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter,
01/2017
Conference Proceeding
We report on the detection of a very rapid TeV gamma-ray flare from BL Lacertae on 2011 June 28 with the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The flaring activity was ...observed during a 34.6 minute exposure, when the integral flux above 200 GeV reached (3.4 + or - 0.6) x 10 super(-6) photons m super(-2) s super(-1), roughly 125% of the Crab Nebula flux measured by VERITAS. The light curve indicates that the observations missed the rising phase of the flare but covered a significant portion of the decaying phase. The exponential decay time was determined to be 13 + or - 4 minutes, making it one of the most rapid gamma-ray flares seen from a TeV blazar. The gamma-ray spectrum of BL Lacertae during the flare was soft, with a photon index of 3.6 + or - 0.4, which is in agreement with the measurement made previously by MAGIC in a lower flaring state. Contemporaneous radio observations of the source with the Very Long Baseline Array revealed the emergence of a new, superluminal component from the core around the time of the TeV gamma-ray flare, accompanied by changes in the optical polarization angle. Changes in flux also appear to have occurred at optical, UV, and GeV gamma-ray wavelengths at the time of the flare, although they are difficult to quantify precisely due to sparse coverage. A strong flare was seen at radio wavelengths roughly four months later, which might be related to the gamma-ray flaring activities. We discuss the implications of these multiwavelength results.
The VERITAS array of Cherenkov telescopes has carried out a deep observational program on the nearby dwarf spheroidal galaxy Segue 1. We report on the results of nearly 48 hours of good quality ...selected data, taken between January 2010 and May 2011. No significant gamma -ray emission is detected at the nominal position of Segue 1, and upper limits on the integrated flux are derived. According to recent studies, Segue 1 is the most dark matter-dominated dwarf spheroidal galaxy currently known. We derive stringent bounds on various annihilating and decaying dark matter particle models. The upper limits on the velocity-weighted annihilation cross-section are (sigmav) super(95% CL) <, ~ 10 super(-23) cm super(3) s super(-1), improving our limits from previous observations of dwarf spheroidal galaxies by at least a factor of 2 for dark matter particle masses m sub( chi ) > ~ 300 GeV. The lower limits on the decay lifetime are at the level of tau super(95% CL) > ~ 10 super(24) s. Finally, we address the interpretation of the cosmic ray lepton anomalies measured by ATIC and PAMELA in terms of dark matter annihilation, and show that the VERITAS observations of Segue 1 disfavor such a scenario.
Observations of radio halos and relics in galaxy clusters indicate efficient electron acceleration. We report here on VHE gamma-ray observations of the Coma galaxy cluster with the VERITAS array of ...imaging Cerenkov telescopes, with complementing Fermi Large Area Telescope observations at GeV energies. We use the gamma-ray upper limits to constrain cosmic rays (CRs) and magnetic fields in Coma. Using an analytical approach, the CR-to-thermal pressure ratio is constrained to be <16% from VERITAS data and <1.7% from Fermi data (averaged within the virial radius). These upper limits are starting to constrain the CR physics in self-consistent cosmological cluster simulations and cap the maximum CR acceleration efficiency at structure formation shocks to be <50%. Finally, since galaxy clusters are dark matter (DM) dominated, the VERITAS upper limits have been used to place constraints on the thermally averaged product of the total self-annihilation cross section and the relative velocity of the DM particles, left angle bracket sigmavright angle bracket.
The five cysteines closest to the carboxyl terminus of human ferrochelatase have been individually mutated to serine, histidine, or aspartate residues in an attempt to identify the protein ligands to ...the 2Fe-2S cluster. Mutations of cysteines at positions 403, 406, and 411 (C403D, C403H, C406D, C406H, C406S, C411H, and C411S mutants) all resulted in inactive enzyme that failed to assemble the 2Fe-2S cluster as judged by whole-cell EPR studies. In contrast, mutation of the cysteines at positions 360 and 395 to serines (C360S and C395S mutants) did not affect the enzymatic activity, and the resulting enzyme assembled a 2Fe-2S cluster that was spectroscopically indistinguishable from the wild-type enzyme. The results indicate that three of the conserved cysteines in the 30-residue C-terminal extension of mammalian ferrochelatase are involved in ligating the 2Fe-2S cluster. Resonance Raman and variable-temperature magnetic circular dichroism studies of heme-free preparations of human ferrochelatase are reported, and the spectra are best interpreted in terms of one non-cysteinyl, oxygenic ligand for the 2Fe-2S cluster. Such anomalous coordination could account for the cluster lability compared to similar clusters with complete cysteinyl ligation and hence may be intrinsic to the proposed regulatory role for this cluster in mammalian ferrochelatases.
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