8,221 research outputs found
Characterizing the University of California's tenure-track teaching position from the faculty and administrator perspectives.
Teaching faculty are a potential mechanism to generate positive change in undergraduate STEM education. One such type of faculty is the Lecturer with Potential Security of Employment (L(P)SOE), a tenure-track faculty line within the University of California (UC) system. As a foundation for future studies, we sought to characterize individuals in the L(P)SOE position in terms of their background training, job expectations, and resources available for their success. Data were collected through an online survey completed by over 80% of STEM L(P)SOEs across the UC system, as well as interviews with over 20 deans and chairs in STEM departments at three UC campuses. From this work, we found that the majority of current L(P)SOEs were formally trained within their disciplines and not in an education field; however, they possessed substantial education experience, such as classroom teaching or participation in professional development opportunities. Expectations for time spent on teaching, research, and service are aligned between individuals within varying ranks of the L(P)SOE faculty and between L(P)SOEs and administrators. L(P)SOEs and administrators are also in agreement about what constitutes acceptable professional development activities. Interestingly, we identified differences that may reflect changes in the position over time, including increased start-up funds for more recently hired L(P)SOE faculty and a differing perspective on the role of discipline-based education research and scholarly activities between non-tenured and more senior L(P)SOEs. Overall, these data provide a snapshot of the L(P)SOE position that will aid in future work to identify the potential institutional impact of these individuals
Mechanism for current saturation and energy dissipation in graphene transistors
From a combination of careful and detailed theoretical and experimental
studies, we demonstrate that the Boltzmann theory including all scattering
mechanisms gives an excellent account, with no adjustable parameters, of high
electric field transport in single as well as double-oxide graphene
transistors. We further show unambiguously that scattering from the substrate
and superstrate surface optical (SO) phonons governs the high field transport
and heat dissipation over a wide range of experimentally relevant parameters.
Models that neglect SO phonons altogether or treat them in a simple
phenomenological manner are inadequate. We outline possible strategies for
achieving higher current and complete saturation in graphene devices.Comment: revtex, 5 pages, 3 figures, to appear in Phys. Rev. Lett
Joining the dots: devising a supported self-help strategy to help pituitary patients integrate their medical care
Efficacy and effectiveness of dihydroartemisinin-piperaquine versus artesunate-mefloquine in falciparum malaria: an open-label randomised comparison.
BACKGROUND: Artemisinin-based combinations are judged the best treatments for multidrug-resistant Plasmodium falciparum malaria. Artesunate-mefloquine is widely recommended in southeast Asia, but its high cost and tolerability profile remain obstacles to widespread deployment. To assess whether dihydroartemisinin-piperaquine is a suitable alternative to artesunate-mefloquine, we compared the safety, tolerability, efficacy, and effectiveness of the two regimens for the treatment of uncomplicated falciparum in western Myanmar (Burma). METHODS: We did an open randomised comparison of 3-day regimens of artesunate-mefloquine (12/25 mg/kg) versus dihydroartemisinin-piperaquine (6.3/50 mg/kg) for the treatment of children aged 1 year or older and in adults with uncomplicated falciparum malaria in Rakhine State, western Myanmar. Within each group, patients were randomly assigned supervised or non-supervised treatment. The primary endpoint was the PCR-confirmed parasitological failure rate by day 42. Failure rates at day 42 were estimated by Kaplan-Meier survival analysis. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN27914471. FINDINGS: Of 652 patients enrolled, 327 were assigned dihydroartemisinin-piperaquine (156 supervised and 171 not supervised), and 325 artesunate-mefloquine (162 and 163, respectively). 16 patients were lost to follow-up, and one patient died 22 days after receiving dihydroartemisinin-piperaquine. Recrudescent parasitaemias were confirmed in only two patients; the day 42 failure rate was 0.6% (95% CI 0.2-2.5) for dihydroartemisinin-piperaquine and 0 (0-1.2) for artesunate-mefloquine. Whole-blood piperaquine concentrations at day 7 were similar for patients with observed and non-observed dihydroartemisinin-piperaquine treatment. Gametocytaemia developed more frequently in patients who had received dihydroartemisinin-piperaquine than in those on artesunate-mefloquine: day 7, 18 (10%) of 188 versus five (2%) of 218; relative risk 4.2 (1.6-11.0) p=0.011. INTERPRETATION: Dihydroartemisinin-piperaquine is a highly efficacious and inexpensive treatment of multidrug-resistant falciparum malaria and is well tolerated by all age groups. The effectiveness of the unsupervised treatment, as in the usual context of use, equalled its supervised efficacy, indicating good adherence without supervision. Dihydroartemisinin-piperaquine is a good alternative to artesunate-mefloquine
Measurement of Resonant Frequency and Quality Factor of Microwave Resonators: Comparison of Methods
Precise microwave measurements of sample conductivity, dielectric, and
magnetic properties are routinely performed with cavity perturbation
measurements. These methods require the accurate determination of quality
factor and resonant frequency of microwave resonators. Seven different methods
to determine the resonant frequency and quality factor from complex
transmission coefficient data are discussed and compared to find which is most
accurate and precise when tested using identical data. We find that the
nonlinear least-squares fit to the phase vs. frequency is the most accurate and
precise when the signal-to-noise ratio is greater than 65. For noisier data,
the nonlinear least squares fit to a Lorentzian curve is more accurate and
precise. The results are general and can be applied to the analysis of many
kinds of resonant phenomena.Comment: 29 pages, 11 figure
The first high-amplitude delta Scuti star in an eclipsing binary system
We report the discovery of the first high-amplitude delta Scuti star in an
eclipsing binary, which we have designated UNSW-V-500. The system is an
Algol-type semi-detached eclipsing binary of maximum brightness V = 12.52 mag.
A best-fitting solution to the binary light curve and two radial velocity
curves is derived using the Wilson-Devinney code. We identify a late A spectral
type primary component of mass 1.49+/-0.02 M_sun and a late K spectral type
secondary of mass 0.33+/-0.02 M_sun, with an inclination of 86.5+/-1.0 degrees,
and a period of 5.3504751+/-0.0000006 d. A Fourier analysis of the residuals
from this solution is performed using PERIOD04 to investigate the delta Scuti
pulsations. We detect a single pulsation frequency of f_1 = 13.621+/-0.015 c/d,
and it appears this is the first overtone radial mode frequency. This system
provides the first opportunity to measure the dynamical mass for a star of this
variable type; previously, masses have been derived from stellar evolution and
pulsation models.Comment: 7 pages, 6 figures, 2 tables, for submission to MNRAS, v2: paper size
change, small typographical changes to abstrac
Angiosarcoma of the vulva
Objective: Angiosarcoma is a rare neoplasm typically presenting in the skin and superficial soft tissues, with an equal female-to-male ratio. We present a woman with recurrent vulvar lesions and a history of melanoma found to have angiosarcoma.
Case: A 67-year-old woman presented with a seven month history of recurrent vulvar lesions with symptoms of discomfort and bleeding. The histopathological diagnosis revealed high-grade angiosarcoma. Computed tomographic imaging with contrast and positron emission tomography revealed disseminated disease. She underwent chemotherapy and radiation but died within one year of diagnosis.
Conclusions: The prognosis for patients with angiosarcoma is generally poor, especially with disseminated disease. Early detection remains the key element in maximizing patient outcomes
Asymmetric quantum error correction via code conversion
In many physical systems it is expected that environmental decoherence will
exhibit an asymmetry between dephasing and relaxation that may result in qubits
experiencing discrete phase errors more frequently than discrete bit errors. In
the presence of such an error asymmetry, an appropriately asymmetric quantum
code - that is, a code that can correct more phase errors than bit errors -
will be more efficient than a traditional, symmetric quantum code. Here we
construct fault tolerant circuits to convert between an asymmetric subsystem
code and a symmetric subsystem code. We show that, for a moderate error
asymmetry, the failure rate of a logical circuit can be reduced by using a
combined symmetric asymmetric system and that doing so does not preclude
universality.Comment: 5 pages, 8 figures, presentation revised, figures and references
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