2,639 research outputs found
Physical Properties of OSIRIS-REx Target Asteroid (101955) 1999 RQ36 derived from Herschel, ESO-VISIR and Spitzer observations
In September 2011, the Herschel Space Observatory performed an observation
campaign with the PACS photometer observing the asteroid (101955) 1999 RQ36 in
the far infrared. The Herschel observations were analysed, together with ESO
VLT-VISIR and Spitzer-IRS data, by means of a thermophysical model in order to
derive the physical properties of 1999 RQ36. We find the asteroid has an
effective diameter in the range 480 to 511 m, a slightly elongated shape with a
semi-major axis ratio of a/b=1.04, a geometric albedo of 0.045 +0.015/-0.012,
and a retrograde rotation with a spin vector between -70 and -90 deg ecliptic
latitude. The thermal emission at wavelengths below 12 micron -originating in
the hot sub-solar region- shows that there may be large variations in roughness
on the surface along the equatorial zone of 1999 RQ36, but further measurements
are required for final proof. We determine that the asteroid has a
disk-averaged thermal inertia of Gamma = 650 Jm-2s-0.5K-1 with a 3-sigma
confidence range of 350 to 950 Jm-2s-0.5K-1, equivalent to what is observed for
25143 Itokawa and suggestive that 1999 RQ36 has a similar surface texture and
may also be a rubble-pile in nature. The low albedo indicates that 1999 RQ36
very likely contains primitive volatile-rich material, consistent with its
spectral type, and that it is an ideal target for the OSIRIS-REx sample return
mission.Comment: Accepted for publication in Astronomy & Astrophysics, 9 pages, 7
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Clinician experiences on training and awareness of sexual orientation in NHS Talking Therapies Services for Anxiety and Depression
Previous research that explored sexual minority service usersâ experiences of accessing NHS Talking Therapies
for Anxiety and Depression Services highlighted the need for specific sexual orientation training. Inconsistent or lack of training may contribute to disparities in treatment outcomes between sexual minority service users and heterosexual service users. The aim of the study was to explore cliniciansâ competencies working with sexual minority service users, their experiences of sexual orientation training, their view of current gaps intraining provision, and ways to improve training. Self-reported sexual orientation competency scales and open ended
questions were used to address the aims of the study. Participants (n=83) included Psychological
Wellbeing Practitioners (PWPs) and high-intensity CBT therapists (HITs). Responses on competency scales
were analysed using KruskalâWallis tests and thematic analysis was used to analyse qualitative responses.
Participants who identified as 25â29 years old had higher scores on the knowledge scale than 45+-year-olds.Bisexual participants also had higher scores on the knowledge subscale than heterosexual participants. Threeover-arching themes were identified: (a) training received on sexual minority issues by Talking Therapies
clinicians, (b) cliniciansâ experiences of accessing and receiving sexual minority training, and (c) perceived gaps in current sexual minority training and ways to improve training. Findings were linked to previous literature and recommendations to stakeholders are made throughout the Discussion section with the view of improving sexual orientation training
Locked and Unlocked Polygonal Chains in 3D
In this paper, we study movements of simple polygonal chains in 3D. We say
that an open, simple polygonal chain can be straightened if it can be
continuously reconfigured to a straight sequence of segments in such a manner
that both the length of each link and the simplicity of the chain are
maintained throughout the movement. The analogous concept for closed chains is
convexification: reconfiguration to a planar convex polygon. Chains that cannot
be straightened or convexified are called locked. While there are open chains
in 3D that are locked, we show that if an open chain has a simple orthogonal
projection onto some plane, it can be straightened. For closed chains, we show
that there are unknotted but locked closed chains, and we provide an algorithm
for convexifying a planar simple polygon in 3D with a polynomial number of
moves.Comment: To appear in Proc. 10th ACM-SIAM Sympos. Discrete Algorithms, Jan.
199
Mott transition in the -flux SU() Hubbard model on a square lattice
We employ the projector quantum Monte Carlo simulations to study the
ground-state properties of the square-lattice SU(4) Hubbard model with a
flux per plaquette. In the weak coupling regime, its ground state is in the
gapless Dirac semi-metal phase. With increasing repulsive interaction, we show
that, a Mott transition occurs from the semimetal to the valence bond solid,
accompanied by the discrete symmetry breaking. Our simulations
demonstrate the existence of a second-order phase transition, which confirms
the Ginzburg-Landau analysis. The phase transition point and the critical
exponent are also estimated. To account for the effect of a flux
on the ordering in the strong coupling regime, we analytically derive by the
perturbation theory the ring-exchange term which describes the leading-order
difference between the -flux and zero-flux SU(4) Hubbard models.Comment: 8 pages, 9 figure
Prognostic Value and Potential Immunoregulatory Role of SCARF1 in Hepatocellular Carcinoma
Scavenger receptor class F member 1 (SCARF1) is thought to play an important role in the selective recruitment of CD4(+) T cells to liver sinusoidal endothelial cells during chronic liver disease. However, the contribution of SCARF1 to hepatocellular carcinoma (HCC) is currently unknown. We utilized publically-available RNA-sequencing data from The Cancer Genome Atlas (TGCA) to explore SCARF1 expression in HCC and correlated it with a number of clinicopathological features. Flow adhesion assays were used to determine the role of SCARF1 in CD4(+) T cell subset recruitment. SCARF1 expression was downregulated in HCC tumor tissues, compared to non-tumoral tissues, and loss of SCARF1 expression was associated with poorly differentiated/aggressive tumors. Additionally, higher SCARF1 expression in HCC tumor tissues was highly prognostic of better overall, disease-free and progression-free survival. SCARF1 within HCC was largely associated with tumor endothelial cells and adhesion studies suggested that it played a role in the specific recruitment of proinflammatory CD4(+) T cells (CD4(+)CD25(â)) to HCC tumor tissues. Endothelial SCARF1 expression in tumor biopsies may provide critical prognostic information. Additionally, SCARF1 may also be a novel endothelial target that could help re-programme the microenvironment of HCC by promoting effector T cell tumor infiltration
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Defining glial cell self-alignment parameters for 3D CNS tissue models
Long-term and trans-generational effects of neonatal experience on sheep behaviour
Early life experiences can have profound long-term, and sometimes trans-generational, effects on individual phenotypes. However, there is a relative paucity of knowledge about effects on pain sensitivity, even though these may impact on an individual's health and welfare, particularly in farm animals exposed to painful husbandry procedures. Here, we tested in sheep whether neonatal painful and non-painful challenges can alter pain sensitivity in adult life, and also in the next generation. Ewes exposed to tail-docking or a simulated mild infection (lipopolysaccharide (LPS)) on days 3â4 of life showed higher levels of pain-related behaviour when giving birth as adults compared with control animals. LPS-treated ewes also gave birth to lambs who showed decreased pain sensitivity in standardized tests during days 2â3 of life. Our results demonstrate long-term and trans-generational effects of neonatal experience on pain responses in a commercially important species and suggest that variations in early life management can have important implications for animal health and welfare
Quasi-degenerate self-trapping in one-dimensional charge transfer exciton
The self-trapping by the nondiagonal particle-phonon interaction between two
quasi-degenerate energy levels of excitonic system, is studied. We propose this
is realized in charge transfer exciton, where the directions of the
polarization give the quasi-degeneracy. It is shown that this mechanism, unlike
the conventional diagonal one, allows a coexistence and resonance of the free
and self-trapped states even in one-dimensional systems and a quantitative
theory for the optical properties (light absorption and time-resolved
luminescence) of the resonating states is presented. This theory gives a
consistent resolution for the long-standing puzzles in quasi-one-dimensional
compound A-PMDA.Comment: accepted to Phys. Rev. Letter
Physical Properties of Asteroid (308635) 2005 YU55 derived from multi-instrument infrared observations during a very close Earth-Approach
The near-Earth asteroid (308635) 2005 YU55 is a potentially hazardous
asteroid which was discovered in 2005 and passed Earth on November 8th 2011 at
0.85 lunar distances. This was the closest known approach by an asteroid of
several hundred metre diameter since 1976 when a similar size object passed at
0.5 lunar distances. We observed 2005 YU55 from ground with a recently
developed mid-IR camera (miniTAO/MAX38) in N- and Q-band and with the
Submillimeter Array (SMA) at 1.3 mm. In addition, we obtained space
observations with Herschel/PACS at 70, 100, and 160 micron. Our thermal
measurements cover a wide range of wavelengths from 8.9 micron to 1.3 mm and
were taken after opposition at phase angles between -97 deg and -18 deg. We
performed a radiometric analysis via a thermophysical model and combined our
derived properties with results from radar, adaptive optics, lightcurve
observations, speckle and auxiliary thermal data. We find that (308635) 2005
YU55 has an almost spherical shape with an effective diameter of 300 to 312 m
and a geometric albedo pV of 0.055 to 0.075. Its spin-axis is oriented towards
celestial directions (lam_ecl, beta_ecl) = (60 deg +/- 30deg, -60 deg +/- 15
deg), which means it has a retrograde sense of rotation. The analysis of all
available data combined revealed a discrepancy with the radar-derived size. Our
radiometric analysis of the thermal data together with the problem to find a
unique rotation period might be connected to a non-principal axis rotation. A
low to intermediate level of surface roughness (r.m.s. of surface slopes in the
range 0.1 - 0.3) is required to explain the available thermal measurements. We
found a thermal inertia in the range 350-800 Jm^-2s^-0.5K^-1, very similar to
the rubble-pile asteroid (25143) Itokawa and indicating a mixture of low
conductivity fine regolith with larger rocks and boulders of high thermal
inertia on the surface.Comment: Accepted for publication in Astronomy & Astrophysics, 12 pages, 10
figure
Combining transcriptome analyses and virus induced gene silencing to identify genes in the Rpp4-mediated asian soybean rust resistance Pathway.
Six Asian Soybean Rust (ASR) resistance loci have been identified and mapped in soybean genome: Rpp1 (Resistance to Phakopsora pachyrhizi 1), Rpp2, Rpp3, Rpp4, Rpp5 and Rpp6. Of particular interest is Rpp4, which has remained stable and confers resistance against Phakopsora pachyrhizi isolates from around the world. Sequencing of the region harboring Rpp4 in the susceptible cultivar Williams 82 (Wm82) and the resistant cultivar (PI459025B) genotype identified a cluster of CC-NBS-LRR resistance genes. Meyers et al. (2009) developed Virus Induced Gene Silencing constructs from the LRR regions of the Wm82 Rpp4 candidate genes to confirm that orthologous genes were responsible for resistance in the resistant parent (PI459025B). In this study, RNA samples extracted from the same Rpp4 LRR silenced and empty vector treated plants, also infected with P. pachyrhizi (described by Meyer et al., 2009) were compared using the GeneChipÂź Soybean Genome Array (AffymetrixÂź). Since the plant samples differed only in the expression of Rpp4, comparisons of these samples would identify genes downstream of Rpp4 in the signaling pathway. In total, 383 differentially expressed probes were identified, many with functions related to defense. While the time point analyzed was late in defense signaling, bioinformatic approaches were useful in characterizing the defense response and identify transcription factors regulating the response
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