623 research outputs found
Remotely Readable Fiber Optic Compass
PatentA remotely readable fiber optic compass. A sheet polarizer
is affixed to a magnet rotatably mounted in a compass
body, such that the polarizer rotates with the magnet.
The optical axis of the sheet polarizer is preferably
aligned with the north-south axis of the magnet. A single
excitation light beam is divided into four identical
beams, two of which are passed through the sheet polarizer
and through two fixed polarizing sheets which have
their optical axes at right angles to one another. The
angle of the compass magnet with respect to a fixed axis
of the compass body can be determined by measuring
the ratio of the intensities of the two light beams. The
remaining ambiguity as to which of the four possible
quadrants the magnet is pointing to is resolved by the
second pair of light beams, which are passed through
the sheet polarizer at positions which are transected by
two semicircular opaque strips formed on the sheet
polarizer. The incoming excitation beam and the four
return beams are communicated by means of optical
fibers, giving a remotely readable compass which has
no electrical parts
Kepler-445, Kepler-446 And The Occurrence Of Compact Multiples Orbiting Mid-M Dwarf Stars
We confirm and characterize the exoplanetary systems Kepler-445 and Kepler-446: two mid-M dwarf stars, each with multiple, small, short-period transiting planets. Kepler-445 is a metal-rich ([ Fe/H] = + 0.25 0.10) M4 dwarf with three transiting planets, and Kepler-446 is a metal-poor ([ Fe/H] = -0.30 0.10) M4 dwarf also with three transiting planets. Kepler-445c is similar toGJ 1214b: both in planetary radius and the properties of the host star. The Kepler-446 system is similar to the Kepler-42 system: both are metal-poor with large galactic space velocities and three short-period, likely rocky transiting planets that were initially assigned erroneously large planet-to-star radius ratios. We independently determined stellar parameters from spectroscopy and searched for and fitted the transit light curves for the planets, imposing a strict prior on stellar density in order to remove correlations between the fitted impact parameter and planet-to-star radius ratio for short-duration transits. Combining Kepler-445, Kepler-446, and Kepler-42, and isolating all mid-M dwarf stars observed by Kepler with the precision necessary to detect similar systems, we calculate that 21+ 7 -5 % of mid-M dwarf stars host compact multiples ( multiple planets with periods of less than 10 days) for a wide range of metallicities. We suggest that the inferred planet masses for these systems support highly efficient accretion of protoplanetary disk metals by mid-M dwarf protoplanets.NSF DGE1144152, AST-1005313NASA NAS5-26555NASA Office of Space Science NNX13AC07GAstronom
Touchstone Stars: Highlights from the Cool Stars 18 Splinter Session
We present a summary of the splinter session on "touchstone stars" -- stars
with directly measured parameters -- that was organized as part of the Cool
Stars 18 conference. We discuss several methods to precisely determine cool
star properties such as masses and radii from eclipsing binaries, and radii and
effective temperatures from interferometry. We highlight recent results in
identifying and measuring parameters for touchstone stars, and ongoing efforts
to use touchstone stars to determine parameters for other stars. We conclude by
comparing the results of touchstone stars with cool star models, noting some
unusual patterns in the differences.Comment: Proceedings of the 18th Cambridge Workshop on Cool Stars, Stellar
Systems, and the Sun, Eds G. van Belle & H. Harri
Risk of vicarious trauma in nursing research:a focused mapping review and synthesis
AIMS AND OBJECTIVES: To provide a snapshot of how vicarious trauma is considered within the published nursing research literature. BACKGROUND: Vicarious trauma (secondary traumatic stress) has been the focus of attention in nursing practice for many years. The most pertinent areas to invoke vicarious trauma in research have been suggested as abuse/violence and death/dying. What is not known is how researchers account for the risks of vicarious trauma in research. DESIGN: Focused mapping review and synthesis. Empirical studies meeting criteria for abuse/violence or death/dying in relevant Scopus ranked top nursing journals (n = 6) January 2009 to December 2014. METHODS: Relevant papers were scrutinised for the extent to which researchers discussed the risk of vicarious trauma. Aspects of the studies were mapped systematically to a pre-defined template, allowing patterns and gaps in authors' reporting to be determined. These were synthesised into a coherent profile of current reporting practices and from this, a new conceptualisation seeking to anticipate and address the risk of vicarious trauma was developed. RESULTS: Two thousand five hundred and three papers were published during the review period, of which 104 met the inclusion criteria. Studies were distributed evenly by method (52 qualitative; 51 quantitative; one mixed methods) and by focus (54 abuse/violence; 50 death/dying). The majority of studies (98) were carried out in adult populations. Only two papers reported on vicarious trauma. CONCLUSION: The conceptualisation of vicarious trauma takes account of both sensitivity of the substantive data collected, and closeness of those involved with the research. This might assist researchers in designing ethical and protective research and foreground the importance of managing risks of vicarious trauma. RELEVANCE TO CLINICAL PRACTICE: Vicarious trauma is not well considered in research into clinically important topics. Our proposed framework allows for consideration of these so that precautionary measures can be put in place to minimise harm to staff
Characterization of coarse aggregate angularity using digital image processing
This thesis involves a comparative analysis between well-established physically performed measurements for coarse aggregate and an image-based system. A thorough literature review was conducted, focusing on the importance of aggregate shape and how it is measured. In addition, state of the art in image-based aggregate measurement was reviewed along with the impacts and difficulties of an image-based methodology. Physical testing, consisting of Uncompacted Void Content, Index of Particle Shape and Texture (Compacted Voids), and Percent of Fractured Particles (fractured face or crush counts), was performed on aggregate control samples prior to testing on bulk aggregate samples. All aggregate samples were then tested with the WipShape imaging system to obtain Minimum Average Curve Radius measurement data. Finally, the results of physical testing and Minimum Average Curve Radius measurements were analyzed to determine if correlations exist between the different methods --Introduction, page 2-3
Magnetic Inflation and Stellar Mass. I. Revised Parameters for the Component Stars of the Kepler Low-mass Eclipsing Binary T-Cyg1-12664
Several low-mass eclipsing binary stars show larger than expected radii for their measured mass, metallicity, and age. One proposed mechanism for this radius inflation involves inhibited internal convection and starspots caused by strong magnetic fields. One particular eclipsing binary, T-Cyg1-12664, has proven confounding to this scenario. Çakırlı et al. measured a radius for the secondary component that is twice as large as model predictions for stars with the same mass and age, but a primary mass that is consistent with predictions. Iglesias-Marzoa et al. independently measured the radii and masses of the component stars and found that the radius of the secondary is not in fact inflated with respect to models, but that the primary is, which is consistent with the inhibited convection scenario. However, in their mass determinations, Iglesias-Marzoa et al. lacked independent radial velocity measurements for the secondary component due to the star's faintness at optical wavelengths. The secondary component is especially interesting, as its purported mass is near the transition from partially convective to a fully convective interior. In this article, we independently determined the masses and radii of the component stars of T-Cyg1-12664 using archival Kepler data and radial velocity measurements of both component stars obtained with IGRINS on the Discovery Channel Telescope and NIRSPEC and HIRES on the Keck Telescopes. We show that neither of the component stars is inflated with respect to models. Our results are broadly consistent with modern stellar evolutionary models for main-sequence M dwarf stars and do not require inhibited convection by magnetic fields to account for the stellar radii
Low fitness partially explains resting metabolic rate differences between African American and white women
Background High levels of obesity among African American women have been hypothesized to be partially resultant from a lower resting metabolic rate compared with white women. The aim of the current study was to determine if differences in cardiorespiratory fitness and moderate-to-vigorous physical activity are associated with differences in resting metabolic rate among free-living young adult African American women and white women. Methods Participants were 179 women (white women n = 141, African American women n = 38, mean age = 27.7 years). Resting metabolic rate was measured using indirect calorimetry, body composition using dual energy x-ray absorptiometry, cardiorespiratory fitness via maximal treadmill test, and moderate-to-vigorous physical activity using an activity monitor. Results African American women had higher body mass index, fat mass, and fat-free mass compared with white women but lower levels of cardiorespiratory fitness. No differences were observed between African American and white women in resting metabolic rate when expressed as kcal/day (1390.8 ± 197.5 vs 1375.7 ± 173.6 kcal/day, P =.64), but African American women had a lower resting metabolic rate when expressed relative to body weight (2.56 ± 0.30 vs 2.95 ± 0.33 mL/kg/min,
Effects of differentiation on purinergic and neurotensin-mediated calcium signaling in human HT-29 colon cancer cells
Calcium signaling is a key regulator of processes important in differentiation. In colon cancer cells differentiation is associated with altered expression of specific isoforms of calcium pumps of the endoplasmic reticulum and the plasma membrane, suggesting that differentiation of colon cancer cells is associated with a major remodeling of calcium homeostasis. Purinergic and neurotensin receptor activation are known regulators of cytosolic free Ca2+ levels in colon cancer cells. This study aimed to assess changes in cytosolic free Ca2+ levels in response to ATP and neurotensin with differentiation induced by sodium butyrate or culturing post-confluence. Parameters assessed included peak cytosolic free Ca2+ level after activation; time to reach peak cytosolic free Ca2+ and the EC50 of dose response curves. Our results demonstrate that differentiation of HT-29 colon cancer cells is associated with a remodeling of both ATP and neurotensin mediated Ca2+ signaling. Neurotensin-mediated calcium signaling appeared more sensitive to differentiation than ATP-mediated Ca2+ signaling. (c) 2013 Elsevier Inc. All rights reserved
From the Field
These short pieces, written by individuals engaged in sex work-related activism and scholarship, are intended to provide a snapshot of ongoing social justice efforts regarding this highly politicized issue. In the following commentaries, Sienna Baskin documents U.S. efforts to provide legal aid to sex workers and victim-survivors of sex trafficking, Thaddeus Blanchette describes a Brazilian prostitute’s campaign for a seat in Congress, Megan Morgenson speaks to the need to incorporate sex workers’ perspectives into anti-trafficking initiatives, Sarah Jenny Bleviss documents new mobile phone technology designed to help U.S. sex workers navigate the risks they face working in a criminalized profession, and Gregory Mitchell (together with Thaddeus Blanchette) and Jayne Swift detail two events on U.S. campuses designed to promote critical thinking about sex work and trafficking
A second transmissible cancer in Tasmanian devils.
Clonally transmissible cancers are somatic cell lineages that are spread between individuals via the transfer of living cancer cells. There are only three known naturally occurring transmissible cancers, and these affect dogs, soft-shell clams, and Tasmanian devils, respectively. The Tasmanian devil transmissible facial cancer was first observed in 1996, and is threatening its host species with extinction. Until now, this disease has been consistently associated with a single aneuploid cancer cell lineage that we refer to as DFT1. Here we describe a second transmissible cancer, DFT2, in five devils located in southern Tasmania in 2014 and 2015. DFT2 causes facial tumors that are grossly indistinguishable but histologically distinct from those caused by DFT1. DFT2 bears no detectable cytogenetic similarity to DFT1 and carries a Y chromosome, which contrasts with the female origin of DFT1. DFT2 shows different alleles to both its hosts and DFT1 at microsatellite, structural variant, and major histocompatibility complex (MHC) loci, confirming that it is a second cancer that can be transmitted between devils as an allogeneic, MHC-discordant graft. These findings indicate that Tasmanian devils have spawned at least two distinct transmissible cancer lineages and suggest that transmissible cancers may arise more frequently in nature than previously considered. The discovery of DFT2 presents important challenges for the conservation of Tasmanian devils and raises the possibility that this species is particularly prone to the emergence of transmissible cancers. More generally, our findings highlight the potential for cancer cells to depart from their hosts and become dangerous transmissible pathogens.We thank Bill Brown, Phil Iles, Billie Lazenby, Jacinta Marr, Jane McGee, Sarah Peck, Holly Wiersma and Phil Wise for assistance with sample collection and curation. Adrian Baez-Ortega, Andrew Davis, Jo Hanuszewicz, Gina Kalodimos, Amanda Patchett, Narelle Phillips, Elizabeth Reid Swainscoat, Jim Richley, Rachel Stivicic and Jim Taylor assisted with surveying, laboratory analysis, data processing and display. We are grateful for support received from Mike Stratton, the Wellcome Trust Sanger Institute (WTSI) sequencing and informatics teams and the WTSI Cancer Genome Project. This work was supported by a Wellcome Trust Investigator Award (102942/Z/13/Z) and by grants from the Australian Research Council (ARC-DP130100715; ARC-LP130100218). Support was provided by Dr Eric Guiler Tasmanian Devil Research Grants and by the Save the Tasmanian Devil Program. JMCT was partly supported by a Marie Curie Fellowship (FP7-PEOPLE- 2012-IEF, 328364). Sequences associated with this paper have been deposited in Genbank with accession numbers KT188437 and KT188438
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