3,473 research outputs found
Observation of simultaneous fast and slow light
We present a microresonator-based system capable of simultaneously producing
time-advanced and time-delayed pulses. The effect is based on the combination
of a sharp spectral feature with two orthogonally-polarized propagating
waveguide modes. We include an experimental proof-of-concept implementation
using a silica microsphere coupled to a tapered optical fiber and use a
time-domain picture to interpret the observed delays. We also discuss potential
applications for future all-optical networks.Comment: 6 pages, 5 figure
Entangling flux qubits with a bipolar dynamic inductance
We propose a scheme to implement variable coupling between two flux qubits
using the screening current response of a dc Superconducting QUantum
Interference Device (SQUID). The coupling strength is adjusted by the current
bias applied to the SQUID and can be varied continuously from positive to
negative values, allowing cancellation of the direct mutual inductance between
the qubits. We show that this variable coupling scheme permits efficient
realization of universal quantum logic. The same SQUID can be used to determine
the flux states of the qubits.Comment: 4 pages, 4 figure
Effects of a Combined Aquatic Exercise and Walking in Sedentary Obese Females Undergoing a Behavioral Weight-Loss Intervention
Background: The effects of the non-weight bearing method of aquatic exercise as a modality for weight loss have not been established. The purpose of this study was to examine the effects of a combined aquatic exercise and walking program compared to walking alone on body weight and selected variables in obese females undergoing a 16-week Standard Behavioral Treatment (SBT) program. Methods: Forty-four obese (BMI 34.9 ± 3.8 kg·m2) sedentary women (age=40.3 years ± 6.8 yrs) were randomly assigned to either an aquatic exercise (AE) group or a traditional walking (W) exercise only group. Both groups were also required to complete 3 sessions of home based walking per week, and reduce energy intake to facilitate weight loss. Results: In the AE group, total body weight, cardiorespiratory fitness, flexibility, strength, and health-related quality of life outcomes significantly improved over time similar to the W group. Significantly greater enjoyment scores also occurred in the AE group. Conclusion: Aquatic exercise in combination with walking can serve as an alternative to walking exercise alone for overweight women during periods of weight loss, and this can improve functional health status
Rapid Oscillations in Cataclysmic Variables. XVI. DW Cancri
We report photometry and spectroscopy of the novalike variable DW Cancri. The
spectra show the usual broad H and He emission lines, with an excitation and
continuum slope characteristic of a moderately high accretion rate. A
radial-velocity search yields strong detections at two periods, 86.1015(3) min
and 38.58377(6) min. We interpret these as respectively the orbital period
P_orb of the binary, and the spin period P_spin of a magnetic white dwarf. The
light curve also shows the spin period, plus an additional strong signal at
69.9133(10) min, which coincides with the difference frequency
1/P_spin-1/P_orb. These periods are stable over the 1 year baseline of
measurement.
This triply-periodic structure mimics the behavior of several
well-credentialed members of the "DQ Herculis" (intermediate polar) class of
cataclysmic variables. DQ Her membership is also suggested by the mysteriously
strong sideband signal (at nu_spin-nu_orb), attesting to a strong pulsed flux
at X-ray/EUV/UV wavelengths. DW Cnc is a new member of this class, and would be
an excellent target for extended observation at these wavelengths.Comment: PDF, 28 pages, 6 tables, 9 figures; accepted, in press, to appear
June 2004, PASP; more info at http://cba.phys.columbia.edu
Counter and Complicit Masculine Discourse Among Men’s Shed Members
Men’s Sheds is a growing international movement aimed at providing men with places and activities that facilitate social connectedness. Despite Men’s Sheds’ focus on males, little attention has been paid to masculinities within the specific context of these settings. The current study used a gender relations framework to explore the ways in which attendees discussed Men’s Sheds, with particular attention to discussions that were complicit and counter to traditional, hegemonic views of masculinity, and diverse positions in between these binaries. The data consisted of transcripts and field notes from four focus groups comprised of mostly older, White, retired male members of a Canadian shed (N = 22). The analysis revealed three overall themes: (1) focus on work, (2) independence, and (3) need for male-focused spaces. These themes and associated subthemes suggest that shed members ascribe to dominant masculine values and ideals, but also support more fluid and flexible views of masculinity. Implications are discussed for how working with an array of masculinities within the Men’s Sheds movement will be helpful with respect to their future growth in Canada and internationally
"Resurrection of clinical efficacy" after resistance to endocrine therapy in metastatic breast cancer
BACKGROUND: In a significant proportion of metastatic breast cancer (MBC) patients whose tumour has progressed within 6 months of endocrine therapy (de novo resistance), it is generally believed that the chance of achieving clinical benefit (CB) with further endocrine therapy is minimal. METHODS: Data was retrieved from a prospectively updated database of metastatic breast cancer. Relevant data was exported to SPSS™ software for statistical analysis. RESULTS: In oestrogen receptor (ER) positive MBC patients with assessable disease, CB was achieved in 159 (71.3%) (1(st )line) patients. When these patients were put on further endocrine therapy, the CB rates were 63.2% (on 2(nd )line), 46.1% (on 3(rd )line) and 20% (on 4(th )line) with a median duration of response (DOR) in those with CB of 22, 12, 11 and 15 months respectively. The remaining 64(28.7%) patients had de novo resistance on 1(st )line endocrine therapy. Seventeen of these patients were treated with further endocrine therapy. The CB rates were 29.4% (on 2(nd )line) and 22.2% (on 3(rd )line) with a median DOR in those with CB of 22.7 months and 14 months respectively. CONCLUSION: The chance of further endocrine response continues to decrease with each line of therapy, yet CB is still seen with reasonable duration even with a 4(th )line agent. In addition, further endocrine response, with long duration, can be seen in a significant proportion of patients who have developed de novo resistance to 1(st )line endocrine therapy. The use of further endocrine therapy should not be excluded under these circumstances
Determinants of motivation to quit in smokers screened for the early detection of lung cancer:a qualitative study
BACKGROUND: The promotion of smoking cessation within lung cancer screening could lead to benefits for smoking-related disease and improve cost-effectiveness of screening. Little is known about how smokers respond to lung cancer screening and how this impacts smoking behaviour. We aimed to understand how lung cancer screening influences individual motivations about smoking, including in those who have stopped smoking since screening.METHODS: Thirty one long-term smokers aged 51-74 took part in semi-structured interviews about smoking. They had been screened with the EarlyCDT-Lung Test (13 positive result; 18 negative) as part of the Early Cancer Detection Test Lung Cancer Scotland Study. They were purposively sampled for interview based on their self-reported post-screening smoking behaviour. Eleven participants had stopped smoking since screening. Verbatim interview transcripts were analysed using thematic analysis.RESULTS: Two key overarching themes were interpretations of screening test results and emotional responses to those interpretations. Participants' understanding of the risk implied by their test result was often inaccurate, for example a negative result interpreted as an 'all-clear' from lung cancer and a positive result as meaning lung cancer would definitely develop. Those interpretations led to emotional responses (fear, shock, worry, relief, indifferSaveence) influencing motivations about smoking. Other themes included a wake-up call causing changes in perceived risk of smoking-related disease, a feeling that now is the time to stop smoking and family influences. There was no clear pattern in smoking motivations in those who received positive or negative test results. Of those who had stopped smoking, some cited screening experiences as the sole motivation, some cited screening along with other coinciding factors, and others cited non-screening reasons. Cues to change were experienced at different stages of the screening process. Some participants indicated they underwent screening to try and stop smoking, while others expressed little or no desire to stop.CONCLUSIONS: We observed complex and individualised motivations about smoking following lung cancer screening. To be most effective, smoking cessation support in this context should explore understanding of screening test results and may need to be highly tailored to individual emotional responses to screening.</p
G313.3+00.3: A New Planetary Nebula discovered by the Australia Telescope Compact Array and the Spitzer Space Telescope
We present a new planetary nebula, first identified in images from the
Australia Telescope Compact Array, although not recognized at that time. Recent
observations with the Spitzer Space Telescope during the GLIMPSE Legacy program
have rediscovered the object. The high-resolution radio and infrared images
enable the identification of the central star or its wind, the recognition of
the radio emission as thermal, and the probable presence of polycylic aromatic
hydrocarbons in and around the source. These lead to the conclusion that
G313.3+00.3 is a planetary nebula. This object is of particular interest
because it was discovered solely through radio and mid-infrared imaging,
without any optical (or near-infrared) confirmation, and acts as a proof of
concept for the discovery of many more highly extinguished planetary nebulae.
G313.3+00.3 is well-resolved by both the instruments with which it was
identified, and suffers extreme reddening due to its location in the
Scutum-Crux spiral arm.Comment: 18 pages, LaTeX (aastex), incl. 8 PostScript (eps) figures and 1
table. Accepted by ApJ (Part 1
The elastic constants of MgSiO3 perovskite at pressures and temperatures of the Earth's mantle
The temperature anomalies in the Earth's mantle associated with thermal
convection1 can be inferred from seismic tomography, provided that the elastic
properties of mantle minerals are known as a function of temperature at mantle
pressures. At present, however, such information is difficult to obtain
directly through laboratory experiments. We have therefore taken advantage of
recent advances in computer technology, and have performed finite-temperature
ab initio molecular dynamics simulations of the elastic properties of MgSiO3
perovskite, the major mineral of the lower mantle, at relevant thermodynamic
conditions. When combined with the results from tomographic images of the
mantle, our results indicate that the lower mantle is either significantly
anelastic or compositionally heterogeneous on large scales. We found the
temperature contrast between the coldest and hottest regions of the mantle, at
a given depth, to be about 800K at 1000 km, 1500K at 2000 km, and possibly over
2000K at the core-mantle boundary.Comment: Published in: Nature 411, 934-937 (2001
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