1,269 research outputs found
A Quantitative Description of the Content Reading Practices of Beginning Teachers
It is reasonable to assume that today\u27s college literacy instruction addresses a variety of strategies for classroom reading instruction with preservice teachers. This paper describes the classroom practices of 92 K-12 beginning teachers with five or fewer years of teaching experience. We surveyed these 92 teachers relative to their knowledge of, use of, and interest in learning content reading strategies; their sources of information regarding reading strategies, and their confidences and concerils about preparing lessons
Influence of blade aerodynamic model on prediction of helicopter rotor aeroacoustic signatures
Brownâs vorticity transport model has been used to investigate how the local blade aerodynamic model influences the quality of the prediction of the high-frequency airloads associated with bladeâvortex interactions, and thus the accuracy with which the acoustic signature of a helicopter rotor can be predicted. The vorticity transport model can accurately resolve the structure of the wake of the rotor and allows significant flexibility in the way that the blade loading can be represented. The Second Higher-Harmonic Control Aeroacoustics Rotor Test was initiated to provide experimental insight into the acoustic signature of a rotor in cases of strong bladeâvortex interaction. Predictions of two models for the local blade aerodynamics are compared with the test data. A marked improvement in accuracy of the predicted high-frequency airloads and acoustic signature is obtained when a lifting-chord model for the blade aerodynamics is used instead of a lifting-line-type approach. Errors in the amplitude and phase of the acoustic peaks are reduced, and the quality of the prediction is affected to a lesser extent by the computational resolution of the wake, with the lifting-chord model producing the best representation of the distribution of sound pressure below the rotor
Influence of blade aerodynamic model on the prediction of helicopter high-frequency airloads
Brownâs vorticity transport model has been used to investigate the inïŹuence of the blade aerodynamic model on the accuracy with which the high-frequency airloads associated with helicopter bladeâvortex interactions can be predicted. The model yields an accurate representation of the wake structure yet allows signiïŹcant ïŹexibility in the way that the blade loading can be represented. A simple lifting-line model and a somewhat more sophisticated liftingchord model, based on unsteady thin aerofoil theory, are compared. A marked improvement in the accuracy of the predicted high-frequency airloads of the higher harmonic control aeroacoustic rotor is obtained when the liftingchord model is used instead of the lifting-line approach, and the quality of the prediction is affected less by the computational resolution of the wake. The lifting-line model overpredicts the amplitude of the lift response to bladeâvortex interactions as the computational grid is reïŹned, exposing the fundamental deïŹciencies in this approach when modeling the aerodynamic response of the blade to interactions with vortices that are much smaller than its chord. The airloads that are predicted using the lifting-chord model are relatively insensitive to the resolution of the computation, and there are fundamental reasons to believe that properly converged numerical solutions may be attainable using this approach
Machine learning reveals singing rhythms of male Pacific field crickets are clock controlled
Circadian rhythms are ubiquitous in nature and endogenous circadian clocks drive the daily expression of many fitness-related behaviors. However, little is known about whether such traits are targets of selection imposed by natural enemies. In Hawaiian populations of the nocturnally active Pacific field cricket (Teleogryllus oceanicus), males sing to attract mates, yet sexually selected singing rhythms are also subject to natural selection from the acoustically orienting and deadly parasitoid fly, Ormia ochracea. Here, we use T. oceanicus to test whether singing rhythms are endogenous and scheduled by circadian clocks, making them possible targets of se lection imposed by flies. We also develop a novel audio-to-circadian analysis pipeline, capable of extracting useful parameters from which to train machine learning algorithms and process large quantities of audio data. Singing rhythms fulfilled all criteria for endogenous circadian clock control, including being driven by photoschedule, self-sustained periodicity of approximately 24 h, and being robust to variation in temperature. Furthermore, singing rhythms varied across individuals, which might suggest genetic variation on which natural and sexual selection pressures can act. Sexual signals and ornaments are well-known targets of selection by natural enemies, but our findings indicate that the circadian timing of those traitsâ expression may also determine fitnes
A School Nurse-Delivered Intervention for Overweight and Obese Adolescents: Lessons Learned
Dr. Pbert will present work from an academic and community partnership between UMMS and the School Health Unit of the Massachusetts Department of Public Health to design and test a brief intervention for school nurses to provide weight management assistance to overweight and obese adolescents in the school health setting. She will discuss why the school nurse and school health setting are promising venues for addressing adolescent overweight, present results from their pilot study, and discuss facilitators, barriers and strategies to implementing this treatment model
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Using a Robust and Sensitive GFP-Based cGMP Sensor for Real-Time Imaging in Intact Caenorhabditis elegans.
cGMP plays a role in sensory signaling and plasticity by regulating ion channels, phosphodiesterases, and kinases. Studies that primarily used genetic and biochemical tools suggest that cGMP is spatiotemporally regulated in multiple sensory modalities. FRET- and GFP-based cGMP sensors were developed to visualize cGMP in primary cell culture and Caenorhabditis elegans to corroborate these findings. While a FRET-based sensor has been used in an intact animal to visualize cGMP, the requirement of a multiple emission system limits its ability to be used on its own as well as with other fluorophores. Here, we demonstrate that a C. elegans codon-optimized version of the cpEGFP-based cGMP sensor FlincG3 can be used to visualize rapidly changing cGMP levels in living, behaving C. elegans We coexpressed FlincG3 with the blue-light-activated guanylyl cyclases BeCyclOp and bPGC in body wall muscles, and found that the rate of change in FlincG3 fluorescence correlated with the rate of cGMP production by each cyclase. Furthermore, we show that FlincG3 responds to cultivation temperature, NaCl concentration changes, and sodium dodecyl sulfate in the sensory neurons AFD, ASEL/R, and PHB, respectively. Intriguingly, FlincG3 fluorescence in ASEL and ASER decreased in response to a NaCl concentration upstep and downstep, respectively, which is opposite in sign to the coexpressed calcium sensor jRGECO1a and previously published calcium recordings. These results illustrate that FlincG3 can be used to report rapidly changing cGMP levels in an intact animal, and that the reporter can potentially reveal unexpected spatiotemporal landscapes of cGMP in response to stimuli
Possible detection of phase changes from the non-transiting planet HD 46375b by CoRoT
The present work deals with the detection of phase changes in an exoplanetary
system. HD 46375 is a solar analog known to host a non-transiting Saturn-mass
exoplanet with a 3.0236 day period. It was observed by the CoRoT satellite for
34 days during the fall of 2008. We attempt to identify at optical wavelengths,
the changing phases of the planet as it orbits its star. We then try to improve
the star model by means of a seismic analysis of the same light curve and the
use of ground-based spectropolarimetric observations. The data analysis relies
on the Fourier spectrum and the folding of the time series. We find evidence of
a sinusoidal signal compatible in terms of both amplitude and phase with light
reflected by the planet. Its relative amplitude is Delta Fp/F* = [13.0, 26.8]
ppm, implying an albedo A=[0.16, 0.33] or a dayside visible brightness
temperature Tb ~ [1880,2030] K by assuming a radius R=1.1 R_Jup and an
inclination i=45 deg. Its orbital phase differs from that of the
radial-velocity signal by at most 2 sigma_RV. However, the tiny planetary
signal is strongly blended by another signal, which we attribute to a telluric
signal with a 1 day period. We show that this signal is suppressed, but not
eliminated, when using the time series for HD 46179 from the same CoRoT run as
a reference. This detection of reflected light from a non-transiting planet
should be confirmable with a longer CoRoT observation of the same field. In any
case, it demonstrates that non-transiting planets can be characterized using
ultra-precise photometric lightcurves with present-day observations by CoRoT
and Kepler. The combined detection of solar-type oscillations on the same
targets (Gaulme et al. 2010a) highlights the overlap between exoplanetary
science and asteroseismology and shows the high potential of a mission such as
Plato.Comment: 4 pages, 6 figure
Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-beta and Runx2 in bone is required for hearing
Publisher version: http://www.nature.com/embor/journal/v11/n10/full/embor2010135.htmlDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEDA - 20100917 IS - 1469-3178 (Electronic) IS - 1469-221X (Linking) LA - ENG PT - JOURNAL ARTICLEPhysical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown. We show that Runx2, a key lineage-specific transcription factor, regulates the material properties of bone matrix through the same transforming growth factor-beta (TGFbeta)-responsive pathway that controls osteoblast differentiation. Deregulated TGFbeta or Runx2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss, as seen in human cleidocranial dysplasia. In Runx2(+/-) mice, inhibition of TGFbeta signalling rescues both the material properties of the defective matrix, and hearing. This study elucidates the unknown cause of hearing loss in cleidocranial dysplasia, and demonstrates that a molecular pathway controlling cell differentiation also defines material properties of extracellular matrix. Furthermore, our results suggest that the careful regulation of these properties is essential for healthy tissue functio
A Quick Mind with Letters Can Be a Slow Mind with Natural Scenes: Individual Differences in Attentional Selection
Background
Most people show a remarkable deficit in reporting the second of two targets (T2) when presented 200â500 ms after the first (T1), reflecting an âattentional blinkâ (AB). However, there are large individual differences in the magnitude of the effect, with some people, referred to as ânon-blinkersâ, showing no such attentional restrictions.
Methodology/Principal Findings
Here we replicate these individual differences in a task requiring identification of two letters amongst digits, and show that the observed differences in T2 performance cannot be attributed to individual differences in T1 performance. In a second experiment, the generality of the non-blinkers' superior performance was tested using a task containing novel pictures rather than alphanumeric stimuli. A substantial AB was obtained in non-blinkers that was equivalent to that of âblinkersâ.
Conclusion/Significance
The results suggest that non-blinkers employ an efficient target selection strategy that relies on well-learned alphabetic and numeric category sets.University of Groningen. Research School Behavioural and Cognitive Neuroscience
Strain-engineering of the charge and spin-orbital interactions in Sr2IrO4
In the high spin-orbit coupled Sr2IrO4, the high sensitivity of the ground
state to the details of the local lattice structure shows a large potential for
the manipulation of the functional properties by inducing local lattice
distortions. We use epitaxial strain to modify the Ir-O bond geometry in
Sr2IrO4 and perform momentum-dependent Resonant Inelastic X-ray Scattering
(RIXS) at the metal and at the ligand sites to unveil the response of the low
energy elementary excitations. We observe that the pseudospin-wave dispersion
for tensile-strained Sr2IrO4 films displays large softening along the [h,0]
direction, while along the [h,h] direction it shows hardening. This evolution
reveals a renormalization of the magnetic interactions caused by a
strain-driven crossover from anisotropic to isotropic interactions between the
magnetic moments. Moreover, we detect dispersive electron-hole pair excitations
which shift to lower (higher) energies upon compressive (tensile) strain,
manifesting a reduction (increase) in the size of the charge gap. This behavior
shows an intimate coupling between charge excitations and lattice distortions
in Sr2IrO4, originating from the modified hopping elements between the t2g
orbitals. Our work highlights the central role played by the lattice degrees of
freedom in determining both the pseudospin and charge excitations of Sr2IrO4
and provides valuable information towards the control of the ground state of
complex oxides in the presence of high spin-orbit coupling.Comment: Published in Proceedings of the National Academy of Sciences,
September 202
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