257 research outputs found
Measuring and changing negative stuttering stereotypes in adolescents
Stuttering is known to carry stereotypes, e.g., that people who stutter are nervous, anxious, and shy. Research has shown that negative stereotypes about people who stutter exist within the general population. Moreover, negative stereotypes exist among teachers, students, speech-language pathologists, and even the parents of people who stutter. While public opinion of stuttering does not vary dramatically between populations, the ways in which we might change it does. Research has shown that educational videos, books, and classes about stuttering do not appear to significantly alter public opinion positively.;This study compared the effectiveness of two forms of advocacy, a live presentation versus a video presentation, in altering the stuttering stereotype among adolescents. Participants filled out a questionnaire before they were exposed to a 45-minute live presentation or a 45-minute video presentation. After these live and video presentations, they completed a second questionnaire. Then, participants who watched the video were exposed to a shortened 20-minute live presentation followed by a third and final questionnaire.;Results indicated that adolescents showed evidence of negative stereotypes towards people who stutter prior to the presentations. Overall, there were 27 significant positive attitude changes towards stuttering (p \u3c 0.005), 15 for live presentations and 12 for video presentations. Five additional significant positive attitude changes occurred after the video presentation as a result of the shortened live presentation. These findings demonstrate that adolescents\u27 opinions on stuttering can be altered in a positive direction. A live presentation appears to have a greater positive impact on altering attitudes than a video presentation, and moreover, a shortened live presentation following a video presentation can further alter attitudes positively
Spontaneous induction of the uniform lying helix alignment in bimesogenic liquid crystals for the flexoelectro-optic effect
Using in-plane electric fields, the electrical induction of the uniform lying helix (ULH) alignment in chiral nematic liquid crystals is reported. This process permits spontaneous induction of the ULH alignment to give an in-plane optic axis, without the need for complex processing. Flexoelectro-optic switching is subsequently obtained by holding the in-plane electrodes at a common voltage and addressing via a third, plane-parallel electrode on a second, or upper, substrate to give a field across the device in the viewing direction. For this device, in optimized bimesogenic materials, we demonstrate full intensity modulation and sub-millisecond response times at typical device temperatures. (C) 2012 American Institute of Physics. [doi:10.1063/1.3682305]11Nsciescopu
The vertical motions of mono-abundance sub-populations in the Milky Way disk
We present the vertical kinematics of stars in the Milky Way's stellar disk
inferred from SDSS/SEGUE G-dwarf data, deriving the vertical velocity
dispersion, \sigma_z, as a function of vertical height |z| and Galactocentric
radius R for a set of 'mono-abundance' sub-populations of stars with very
similar elemental abundances [\alpha/Fe] and [Fe/H]. We find that all
components exhibit nearly isothermal kinematics in |z|, and a slow outward
decrease of the vertical velocity dispersion: \sigma_z (z,R|[\alpha/Fe],[Fe/H])
~ \sigma_z ([\alpha/Fe],[Fe/H]) x \exp (-(R-R_0)/7 kpc}). The characteristic
velocity dispersions of these components vary from ~ 15 km/s for chemically
young, metal-rich stars, to >~ 50 km/s for metal poor stars. The mean \sigma_z
gradient away from the mid plane is only 0.3 +/- 0.2 km/s/kpc. We find a
continuum of vertical kinetic temperatures (~\sigma^2_z) as function of
([\alpha/Fe],[Fe/H]), which contribute to the stellar surface mass density as
\Sigma_{R_0}(\sigma^2_z) ~ \exp(-\sigma^2_z). The existence of isothermal
mono-abundance populations with intermediate dispersions reject the notion of a
thin-thick disk dichotomy. This continuum of disks argues against models where
the thicker disk portions arise from massive satellite infall or heating;
scenarios where either the oldest disk portion was born hot, or where internal
evolution plays a major role, seem the most viable. The wide range of \sigma_z
([\alpha/Fe],[Fe/H]) combined with a constant \sigma_z(z) for each abundance
bin provides an independent check on the precision of the SEGUE abundances:
\delta_[\alpha/Fe] ~ 0.07 dex and \delta_[Fe/H] ~ 0.15 dex. The radial decline
of the vertical dispersion presumably reflects the decrease in disk
surface-mass density. This measurement constitutes a first step toward a purely
dynamical estimate of the mass profile the disk in our Galaxy. [abridged
PII: S0167-7799(00)01511-0
This article summarizes recent advances in the field of algal hydrogen production. Two fundamental approaches are being developed. One involves the temporal separation of the usually incompatible reactions of O 2 and H 2 production in green algae, and the second involves the use of classical genetics to increase the O 2 tolerance of the reversible hydrogenase enzyme. The economic and environmental impact of a renewable source of H 2 are also discussed
Detection of a glitch in the pulsar J1709-4429
We report the detection of a glitch event in the pulsar J17094429 (also
known as B170644) during regular monitoring observations with the Molonglo
Observatory Synthesis Telescope (UTMOST). The glitch was found during timing
operations, in which we regularly observe over 400 pulsars with up to daily
cadence, while commensally searching for Rotating Radio Transients, pulsars,
and FRBs. With a fractional size of ,
the glitch reported here is by far the smallest known for this pulsar,
attesting to the efficacy of glitch searches with high cadence using UTMOST.Comment: 3 pages, 1 figur
Differences in BVOC oxidation and SOA formation above and below the forest canopy
Gas-phase biogenic volatile organic compounds (BVOCs) are oxidized in the troposphere to produce secondary pollutants such as ozone (O3), organic nitrates (RONO2), and secondary organic aerosol (SOA). Two coupled zero-dimensional models have been used to investigate differences in oxidation and SOA production from isoprene and α-pinene, especially with respect to the nitrate radical (NO3), above and below a forest canopy in rural Michigan. In both modeled environments (above and below the canopy), NO3 mixing ratios are relatively small (<âŻ0.5âŻpptv); however, daytime (08:00â20:00âŻLT) mixing ratios below the canopy are 2 to 3 times larger than those above. As a result of this difference, NO3 contributes 12âŻ% of total daytime α-pinene oxidation below the canopy while only contributing 4âŻ% above. Increasing background pollutant levels to simulate a more polluted suburban or peri-urban forest environment increases the average contribution of NO3 to daytime below-canopy α-pinene oxidation to 32âŻ%. Gas-phase RONO2 produced through NO3 oxidation undergoes net transport upward from the below-canopy environment during the day, and this transport contributes up to 30âŻ% of total NO3-derived RONO2 production above the canopy in the morning (âŒâ07:00). Modeled SOA mass loadings above and below the canopy ultimately differ by less than 0.5âŻÂ”gâŻmâ3, and extremely low-volatility organic compounds dominate SOA composition. Lower temperatures below the canopy cause increased partitioning of semi-volatile gas-phase products to the particle phase and up to 35âŻ% larger SOA mass loadings of these products relative to above the canopy in the model. Including transport between above- and below-canopy environments increases above-canopy NO3-derived α-pinene RONO2 SOA mass by as much as 45âŻ%, suggesting that below-canopy chemical processes substantially influence above-canopy SOA mass loadings, especially with regard to monoterpene-derived RONO2
Intravitreal injection analysis at the Bascom Palmer Eye Institute: evaluation of clinical indications for the treatment and incidence rates of endophthalmitis
To report the incidence of endophthalmitis, in addition to its clinical and microbiological aspects, after intravitreal injection of vascular-targeting agents.
A retrospective review of a consecutive series of 10,142 intravitreal injections of vascular targeting agents (bevacizumab, ranibizumab, triamcinolone acetonide, and preservative-free triamcinolone acetonide) between June 1, 2007 and January 31, 2010, performed by a single service (TGM) at the Bascom Palmer Eye Institute.
One case of clinically-suspected endophthalmitis was identified out of a total of 10,142 injections (0.009%), presenting within three days of injection of bevacizumab. The case was culture-positive for Staphylococcus epidermidis. Final visual acuity was 20/40 after pars plana vitrectomy surgery.
In this series, the incidence of culture-positive endophthalmitis after intravitreal injection of vascular agents in an outpatient setting was very low. We believe that following a standardized injection protocol, adherence to sterile techniques and proper patient follow-up are determining factors for low incidence rates
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