3,217 research outputs found
Minority Stress among Gay and Bisexual Men in Agricultural Occupations
Research integrating the minority stress model and vocational behavior has used broad samples of sexual minority persons. Specific work contexts, particularly traditionally masculine work contexts, may be relevant areas to the integration of minority stress theory and vocational well-being. This study examined the relationship between workplace heterosexism and job satisfaction, as moderated by identity management and person-organization fit, among a sample of 114 sexual minority men, employed in agriculture, recruited from an online social network group. Contrary to prior research, integrating identity management did not moderate the relationship between workplace heterosexism and job satisfaction. Person-organization fit did moderate this relationship, such that the relationship between workplace heterosexism and job satisfaction was negative at high levels of person-organization fit, and positive at low levels of person-organization fit. Our findings add to work on the integration of minority stress theory and vocational behavior by examining these links within a traditionally masculine field
MAPPING BUILDING INTERIORS WITH LIDAR: CLASSIFYING THE POINT CLOUD WITH ARCGIS
Accurate maps of building interiors are needed to support location-based services, plan for emergencies, and manage facilities. However, suitable maps to meet these needs are not available for many buildings. Handheld LiDAR scanners provide an effective tool to collect data for indoor mapping but there are no well-established methods for classifying features in indoor point clouds. The goal of this research was to develop an efficient manual procedure for classifying indoor point clouds to represent features-of-interest.
We used Paracosm’s PX-80 handheld LiDAR scanner to collect point cloud and image data for 11 buildings, which encompassed a variety of architectures. ESRI’s ArcGIS Desktop was used to digitize features that were easily identified in the point cloud and Paracosm’s Retrace was used to digitize features for which imagery was needed for efficient identification. We developed several tools in Python to facilitate the process. We focused on classifying 29 features-of-interest to public safety personnel including walls, doors, windows, fire alarms, smoke detectors, and sprinklers.
The method we developed was efficient, accurate, and allowed successful mapping of features as small as a sprinkler head. Point cloud classification for a 14,000 m2 building took 20–40 hours, depending on building characteristics. Although the method is based on manual digitization, it provides a practical solution for indoor mapping using LiDAR. The methods can be applied in mapping a wide variety of features in indoor or outdoor environments
Juvenile growth and crown morphological plasticity of eastern white pines (Pinus strobus L.) planted along a natural light gradient: Results after six years
Underplanting white pine (Pinus strobus L.) is a promising method to reduce competition and protect against white pine weevil (Pissodes strobi (Peck)) damage. However, shading caused by over-story trees can reduce growth, vigor and survival of white pine. The objective of this study was to determine tile effects of a light gradient on the growth and overall crown morphology of white pine saplings planted in 3-meter strips within a hardwood forest some six years earlier. In 1994, we measured total height and diameter, leader length (in 1994) and numerous crown morphological variables. We then estimated the light environment above the crown of 63 young white pine saplings representing six families of close provenance. White pine grew well (i.e., >20 cm in height/year) for the first six years when planted at light levels between 10 and 66% of full sunlight. Total height and diameter after six years tended to decline more sharply below 30% full sunlight, confirming earlier experiments made in controlled conditions. No significant changes in crown morphology were evident along the light gradient. This lack of crown morphological plasticity presumably contributes to limiting the ability of while pine to grow and compete in a very low light environment. Various silvicultural options are discussed in light of the results obtained in this study
Post-transcriptional gene silencing triggered by sense transgenes involves uncapped antisense RNA and differs from silencing intentionally triggered by antisense transgenes
Although post-transcriptional gene silencing (PTGS) has been studied for more than a decade, there is still a gap in our understanding of how de novo silencing is initiated against genetic elements that are not supposed to produce double-stranded (ds)RNA. Given the pervasive transcription occurring throughout eukaryote genomes, we tested the hypothesis that unintended transcription could produce antisense (as)RNA molecules that participate to the initiation of PTGS triggered by sense transgenes (S-PTGS). Our results reveal a higher level of asRNA in Arabidopsis thaliana lines that spontaneously trigger S-PTGS than in lines that do not. However, PTGS triggered by antisense transgenes (AS-PTGS) differs from S-PTGS. In particular, a hypomorphic ago1 mutation that suppresses S-PTGS prevents the degradation of asRNA but not sense RNA during AS-PTGS, suggesting a different treatment of coding and non-coding RNA by AGO1, likely because of AGO1 association to polysomes. Moreover, the intended asRNA produced during AS-PTGS is capped whereas the asRNA produced during S-PTGS derives from 3' maturation of a read-through transcript and is uncapped. Thus, we propose that uncapped asRNA corresponds to the aberrant RNA molecule that is converted to dsRNA by RNA-DEPENDENT RNA POLYMERASE 6 in siRNA-bodies to initiate S-PTGS, whereas capped asRNA must anneal with sense RNA to produce dsRNA that initiate AS-PTGS
Relativistic effects in a mildly recycled pulsar binary: PSR J1952+2630
We report the results of timing observations of PSR J1952+2630, a 20.7 ms
pulsar in orbit with a massive white dwarf companion. With the increased timing
baseline, we obtain improved estimates for astrometric, spin, and binary
parameters for this system. We get an improvement of an order of magnitude on
the proper motion, and, for the first time, we detect three post-Keplerian
parameters in this system: the advance of periastron, the orbital decay, and
the Shapiro delay. We constrain the pulsar mass to 1.20 and the mass of its companion to 0.97. The current value of is consistent with GR
expectation for the masses obtained using and . The excess
represents a limit on the emission of dipolar GWs from this system. This
results in a limit on the difference in effective scalar couplings for the
pulsar and companion (predicted by scalar-tensor theories of gravity; STTs) of
, which does not yield a
competitive test for STTs. However, our simulations of future campaigns of this
system show that by 2032, the precision of and
will allow for much more precise masses and much tighter constraints on the
orbital decay contribution from dipolar GWs, resulting in . We also present the constraints this
system will place on the parameters of DEF gravity by
2032. They are comparable to those of PSR J1738+0333. Unlike PSR J1738+0333,
PSR J1952+2630 will not be limited in its mass measurement and has the
potential to place even more restrictive limits on DEF gravity in the future.
Further improvements to this test will likely be limited by uncertainties in
the kinematic contributions to due to lack of precise
distance measurements.Comment: 14 pages, 9 figures, 4 tables. Accepted for publication in Astronomy
& Astrophysic
The repeating Fast Radio Burst FRB 121102: Multi-wavelength observations and additional bursts
We report on radio and X-ray observations of the only known repeating Fast
Radio Burst (FRB) source, FRB 121102. We have detected six additional radio
bursts from this source: five with the Green Bank Telescope at 2 GHz, and one
at 1.4 GHz at the Arecibo Observatory for a total of 17 bursts from this
source. All have dispersion measures consistent with a single value (
pc cm) that is three times the predicted maximum Galactic value. The
2-GHz bursts have highly variable spectra like those at 1.4 GHz, indicating
that the frequency structure seen across the individual 1.4 and 2-GHz
bandpasses is part of a wideband process. X-ray observations of the FRB 121102
field with the Swift and Chandra observatories show at least one possible
counterpart; however, the probability of chance superposition is high. A radio
imaging observation of the field with the Jansky Very Large Array at 1.6 GHz
yields a 5 upper limit of 0.3 mJy on any point-source continuum
emission. This upper limit, combined with archival WISE 22-m and IPHAS
H surveys, rules out the presence of an intervening Galactic HII
region. We update our estimate of the FRB detection rate in the PALFA survey to
be 1.1 FRBs sky day (95% confidence)
for peak flux density at 1.4 GHz above 300 mJy. We find that the intrinsic
widths of the 12 FRB 121102 bursts from Arecibo are, on average, significantly
longer than the intrinsic widths of the 13 single-component FRBs detected with
the Parkes telescope.Comment: 18 pages, 5 figures. Accepted for publication in Ap
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