3,707 research outputs found
A study investigating the opinions and experiences of selected teachers regarding teacher bullying
The purpose of this study was to better understand the opinions and experiences of selected teachers regarding teacher bullying at Triton High School. The researcher surveyed teachers with instructional responsibilities. A total of 70 out of 100 teachers participated in the survey. Participants were administered a Likert-scale survey that measured teacher experience with bullying, interpersonal dynamics of bullying teachers, the causes of bullying, and personal experience of bullying. Surveys were statistically analyzed to determine frequencies, percentages, means, and standard deviations on the opinion factors.
The study provides insight on the opinions and experiences of teachers regarding teacher bullying. Teachers at Triton High School agreed that teacher bullying does exist. However, 94% of teachers indicated that they were unaware if the school has a written procedure for handling bullying teachers and 52% of teachers felt administrators were resistant to being told about bullying teachers
Predicting invasive aspergillosis in haematology patients by combining clinical and genetic risk factors with early diagnostic biomarkers
The incidence of invasive aspergillosis (IA) in high risk haematology populations, is relatively low (79.1% in patients with four or more factors. Using a risk threshold of 50%, pre-emptive therapy would have been prescribed in 8.4% of the population
An Arabidopsis protoplast isolation method reduces cytosolic acidification and activation of the chloroplast stress sensor SENSITIVE TO FREEZING 2
Chloroplasts adapt to freezing and other abiotic stresses in part by modifying their membranes. One key-remodeling enzyme is SENSITIVE TO FREEZING2 (SFR2). SFR2 is unusual because it does not respond to initial cold stress or cold acclimation, instead it responds during freezing conditions in Arabidopsis. This response has been shown to be sensitive to cytosolic acidification. The unique lipid products of SFR2 have also been detected in response to non-freezing stresses, but what causes SFR2 to respond in these stresses is unknown. Here, we investigate protoplast isolation as a representative of wounding stress. We show that SFR2 oligogalactolipid products accumulate during protoplast isolation. Notably, we show that protoplast cytosol is acidified during isolation. Modification of the buffers reduces oligogalactolipid accumulation, while prolonged incubation in the isolated state increases it. We conclude that SFR2 activation during protoplast isolation correlates with cytosolic acidification, implying that all SFR2 activation may be dependent on cytosolic acidification. We also conclude that protoplasts can be more gently isolated, reducing their stress
L1 and off Sun-Earth line visible-light imaging of Earth-directed CMEs: An analysis of inconsistent observations
The efficacy of coronal mass ejection (CME) observations as a key input to
space weather forecasting is explored by comparing on and off Sun-Earth line
observations from the ESA/NASA SOHO and NASA STEREO spacecraft. A comparison is
made of CME catalogues based on L1 coronagraph imagery and off Sun-Earth line
coronagraph and heliospheric imager (HI) observations, for the year 2011.
Analysis reveals inconsistencies in the identification of a number of
potentially Earth-directed CMEs. The catalogues reflect our ability to identify
and characterise CMEs, so any discrepancies can impact our prediction of
Earth-directed CMEs. We show that 15 CMEs, which were observed by STEREO, that
had estimated directions compatible with Earth-directed events, had no
identified halo/partial halo counterpart listed in the L1 coronagraph CME
catalogue. In-situ data confirms that for 9 of these there was a consistent L1
Interplanetary CME (ICME). The number of such "discrepant" events is
significant compared to the number of ICMEs recorded at L1 in 2011, stressing
the need to address space weather monitoring capabilities, particularly with
the inclusion of off Sun-Earth line observation. While the study provides
evidence that some halo CMEs are simply not visible in near-Earth coronagraph
imagery, there is evidence that some halo CMEs viewed from L1 are compromised
by preceding CME remnants or the presence of multiple-CMEs. This underlines (1)
the value of multiple vantage point CME observation, and (2) the benefit of off
Sun-Earth line platform heliospheric imaging, and coronagraph imaging, for the
efficient identification and tracking of Earth-directed events.Comment: 36 pages, 6 figures, in press at AGU Space Weather, 202
Fast microwave-driven three-qubit gates for cavity-coupled superconducting qubits
Although single- and two-qubit gates are sufficient for universal quantum computation, single-shot three-qubit gates greatly simplify quantum error correction schemes and algorithms. We design fast, high-fidelity three-qubit entangling gates based on microwave pulses for transmon qubits coupled through a superconducting resonator. We show that when interqubit frequency differences are comparable to single-qubit anharmonicities, errors occur primarily through a single unwanted transition. This feature enables the design of fast three-qubit gates based on simple analytical pulse shapes that are engineered to minimize such errors. We show that a three-qubit ccz gate can be performed in 260 ns with fidelities exceeding 99.38%, or 99.99% with numerical optimization.authorsversionPeer reviewe
The Deformable Mirror Demonstration Mission (DeMi) CubeSat: optomechanical design validation and laboratory calibration
Coronagraphs on future space telescopes will require precise wavefront
correction to detect Earth-like exoplanets near their host stars. High-actuator
count microelectromechanical system (MEMS) deformable mirrors provide wavefront
control with low size, weight, and power. The Deformable Mirror Demonstration
Mission (DeMi) payload will demonstrate a 140 actuator MEMS deformable mirror
(DM) with \SI{5.5}{\micro\meter} maximum stroke. We present the flight
optomechanical design, lab tests of the flight wavefront sensor and wavefront
reconstructor, and simulations of closed-loop control of wavefront aberrations.
We also present the compact flight DM controller, capable of driving up to 192
actuator channels at 0-250V with 14-bit resolution. Two embedded Raspberry Pi 3
compute modules are used for task management and wavefront reconstruction. The
spacecraft is a 6U CubeSat (30 cm x 20 cm x 10 cm) and launch is planned for
2019.Comment: 15 pages, 10 figues. Presented at SPIE Astronomical Telescopes +
Instrumentation, Austin, Texas, US
WASP-33: The first delta Scuti exoplanet host star
We report the discovery of photometric oscillations in the host star of the
exoplanet WASP-33 b (HD 15082). The data were obtained in the R band in both
transit and out-of-transit phases from the 0.3-m telescope and the Montcabrer
Observatory and the 0.8-m telescope at the Montsec Astronomical Observatory.
Proper fitting and subsequent removal of the transit signal reveals stellar
photometric variations with a semi-amplitude of about 1 mmag. The detailed
analysis of the periodogram yields a structure of significant signals around a
frequency of 21 cyc per day, which is typical of delta Scuti-type variable
stars. An accurate study of the power spectrum reveals a possible
commensurability with the planet orbital motion with a factor of 26, but this
remains to be confirmed with additional time-series data that will permit the
identification of the significant frequencies. These findings make WASP-33 the
first transiting exoplanet host star with delta Sct variability and a very
interesting candidate to search for star-planet interactions.Comment: 5 pages, 6 figures. Revised version accepted for publication in A&A
Letter
The elevated Curie temperature and half-metallicity in the ferromagnetic semiconductor LaEuO
Here we study the effect of La doping in EuO thin films using SQUID
magnetometry, muon spin rotation (SR), polarized neutron reflectivity
(PNR), and density functional theory (DFT). The SR data shows that the
LaEuO is homogeneously magnetically ordered up to its
elevated . It is concluded that bound magnetic polaron behavior does
not explain the increase in and an RKKY-like interaction is
consistent with the SR data. The estimation of the magnetic moment by DFT
simulations concurs with the results obtained by PNR, showing a reduction of
the magnetic moment per LaEuO for increasing lanthanum doping.
This reduction of the magnetic moment is explained by the reduction of the
number of Eu-4 electrons present in all the magnetic interactions in EuO
films. Finally, we show that an upwards shift of the Fermi energy with La or Gd
doping gives rise to half-metallicity for doping levels as high as 3.2 %.Comment: 7 pages, 11 figure
Functional Modeling Identifies Paralogous Solanesyl-diphosphate Synthases That Assemble the Side Chain of Plastoquinone-9 in Plastids
Background: Plastid isoforms of solanesyl-diphosphate synthase catalyze the elongation of the prenyl side chain of plastoquinone-9.
Results: Corresponding mutants display lower levels of plastoquinone-9 and plastochromanol-8 and display intact levels of vitamin E.
Conclusion: Plastochromanol-8 originates from a subfraction of non-photoactive plastoquinol-9 and is not essential for seed longevity.
Significance: Viable plastoquinone-9 mutants are invaluable tools for understanding plastid metabolism
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