1,058 research outputs found
Exploding Head Syndrome: Clinical Features, Theories about Etiology, and Prevention Strategies in a Large International Sample
OBJECTIVE: Exploding head syndrome (EHS) is a benign sensory parasomnia characterized by the perception of loud noises or a sense of explosion in the head. Few studies have assessed clinical features and little is known about demographic differences or prevention strategies.
PATIENTS/METHODS: A cross-sectional study of 3286 individuals with and 2954 without lifetime EHS episodes was conducted via online questionnaires.
RESULTS: Those with EHS had shorter sleep durations, longer sleep onset latencies, poorer sleep quality, and less sleep efficiency, but effect sizes for these differences were small. Females were slightly more likely than males to endorse EHS. 44.4% of individuals with EHS experienced significant fear during episodes, but fewer reported clinically significant distress (25.0%) or interference (10.1%) as a result of EHS. Most sufferers believed it to be a brain-based phenomenon, but a small minority endorsed anomalous causes. Five prevention strategies with >50% reported effectiveness were identified.
CONCLUSIONS: EHS was assessed in the largest sample to date. Though associated with clinical impacts, no empirically supported interventions yet exist. The five prevention strategies may prove useful for treatment development
Cost model relationships between textile manufacturing processes and design details for transport fuselage elements
Textile manufacturing processes offer potential cost and weight advantages over traditional composite materials and processes for transport fuselage elements. In the current study, design cost modeling relationships between textile processes and element design details were developed. Such relationships are expected to help future aircraft designers to make timely decisions on the effect of design details and overall configurations on textile fabrication costs. The fundamental advantage of a design cost model is to insure that the element design is cost effective for the intended process. Trade studies on the effects of processing parameters also help to optimize the manufacturing steps for a particular structural element. Two methods of analyzing design detail/process cost relationships developed for the design cost model were pursued in the current study. The first makes use of existing databases and alternative cost modeling methods (e.g. detailed estimating). The second compares design cost model predictions with data collected during the fabrication of seven foot circumferential frames for ATCAS crown test panels. The process used in this case involves 2D dry braiding and resin transfer molding of curved 'J' cross section frame members having design details characteristic of the baseline ATCAS crown design
New infrared star clusters in the Northern and Equatorial Milky Way with 2MASS
We carried out a survey of infrared star clusters and stellar groups on the
2MASS J, H and K_s all-sky release Atlas in the Northern and Equatorial Milky
Way (350 < l < 360, 0 < l < 230). The search in this zone complements that in
the Southern Milky Way (Dutra et al. 2003a). The method concentrates efforts on
the directions of known optical and radio nebulae. The present study provides
167 new infrared clusters, stellar groups and candidates. Combining the two
studies for the whole Milky Way, 346 infrared clusters, stellar groups and
candidates were discovered, whereas 315 objects were previously known. They
constitute an important new sample for future detailed studies.Comment: Accepted to Astronomy and Astrophysic
Study of Photon Dominated Regions in Cepheus B
Aim: The aim of the paper is to understand the emission from the photon
dominated regions in Cepheus B, estimate the column densities of neutral carbon
in bulk of the gas in Cepheus B and to derive constraints on the factors which
determine the abundance of neutral carbon relative to CO. Methods: This paper
presents 15'x15' fully sampled maps of CI at 492 GHz and 12CO 4-3 observed with
KOSMA at 1' resolution. The new observations have been combined with the FCRAO
12CO 1-0, IRAM-30m 13CO 2-1 and C18O 1-0 data, and far-infrared continuum data
from HIRES/IRAS. The KOSMA-tau spherical PDR model has been used to understand
the CI and CO emission from the PDRs in Cepheus B and to explain the observed
variation of the relative abundances of both C^0 and CO. Results: The emission
from the PDR associated with Cepheus B is primarily at V_LSR between -14 and
-11 km s^-1. We estimate about 23% of the observed CII emission from the
molecular hotspot is due to the ionized gas in the HII region. Over bulk of the
material the C^0 column density does not change significantly, (2.0+-1.4)x10^17
cm^-2, although the CO column density changes by an order of magnitude. The
observed \cbyco abundance ratio varies between 0.06 and 4 in Cepheus B. We find
an anti-correlation of the observed C/CO abundance ratio with the observed
hydrogen column density, which holds even when all previous observations
providing C/CO ratios are included. Here we show that this observed variation
of C/CO abundance with total column density can be explained only by clumpy
PDRs consisting of an ensemble of clumps. At high H2 column densities high mass
clumps, which exhibit low C/CO abundance, dominate, while at low column
densities, low mass clumps with high C/CO abundance dominate.Comment: 12 pages, 10 figures, Accepted for publication in A&
Production of two highly abundant 2-methyl-branched fatty acids by blooms of the globally significant marine cyanobacteria Trichodesmium erythraeum
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gosselin, K. M., Nelson, R. K., Spivak, A. C., Sylva, S. P., Van Mooy, B. A. S., Aeppli, C., Sharpless, C. M., O’Neil, G. W., Arrington, E. C., Reddy, C. M., & Valentine, D. L. Production of two highly abundant 2-methyl-branched fatty acids by blooms of the globally significant marine cyanobacteria Trichodesmium erythraeum. ACS Omega, 6(35), (2021): 22803–22810, https://doi.org/10.1021/acsomega.1c03196.The bloom-forming cyanobacteria Trichodesmium contribute up to 30% to the total fixed nitrogen in the global oceans and thereby drive substantial productivity. On an expedition in the Gulf of Mexico, we observed and sampled surface slicks, some of which included dense blooms of Trichodesmium erythraeum. These bloom samples contained abundant and atypical free fatty acids, identified here as 2-methyldecanoic acid and 2-methyldodecanoic acid. The high abundance and unusual branching pattern of these compounds suggest that they may play a specific role in this globally important organism.This work was funded with grants from the National Science Foundation grants OCE-1333148, OCE-1333162, and OCE-1756254 and the Woods Hole Oceanographic Institution (IR&D). GCxGC analysis made possible by WHOI’s Investment in Science Fund
A cluster of outflows in the Vulpecula Rift
We present CO, CO and CO (J=32) observations of a new
cluster of outflows in the Vulpecula Rift with HARP-B on the JCMT. The mass
associated with the outflows, measured using the CO HARP-B observations
and assuming a distance to the region of 2.3 kpc, is 129 \msol{}, while the
mass associated with the dense gas from CO observations is 458 \msol{}
and the associated sub-millimeter core has a mass of 327 112 \msol{}
independently determined from Bolocam 1.1mm data. The outflow-to-core mass
ratio is therefore 0.4, making this region one of the most efficient
observed thus far with more than an order of magnitude more mass in the outflow
than would be expected based on previous results. The kinetic energy associated
with the flows, 94 ergs, is enough to drive the turbulence in
the local clump, and potentially unbind the local region altogether. The
detection of SiO (J=87) emission toward the outflows indicates that the flow
is still active, and not simply a fossil flow. We also model the SEDs of the
four YSOs associated with the molecular material, finding them all to be of mid
to early B spectral type. The energetic nature of the outflows and significant
reservoir of cold dust detected in the sub-mm suggest that these intermediate
mass YSOs will continue to accrete and become massive, rather than reach the
main sequence at their current mass.Comment: 11 pages, 8 figures and 3 tables. Accepted to MNRAS. A
higher-resolution version of figure 1 will be included in the published
version and is available from the authors upon request. Updated with red and
blue wings swapped to match doppler shif
High-resolution FUSE and HST ultraviolet spectroscopy of the white dwarf central star of Sh 2-216
LS V +4621 is the DAO-type central star of the planetary nebula Sh 2-216. We
perform a comprehensive spectral analysis of high-resolution, high-S/N
ultraviolet observations obtained with FUSE and STIS aboard the HST as well as
the optical spectrum of LS V +4621 by means of state-of-the-art NLTE
model-atmosphere techniques in order to compare its photospheric properties to
theoretical predictions from stellar evolution theory as well as from diffusion
calculations.
From the N IV - NV, O IV - O VI, Si IV - Si V, and Fe V - Fe VII ionization
equilibria, we determined an effective temperature of 95 +/- 2 kK with high
precision. The surface gravity is log g = 6.9 +/- 0.2. An unexplained
discrepancy appears between the spectroscopic distance d = 224 +46/-58 pc and
the parallax distance d = 129 +6/-5 pc of LS V +4621. For the first time, we
have identified Mg IV and Ar VI absorption lines in the spectrum of a
hydrogen-rich central star and determined the Mg and Ar abundances as well as
the individual abundances of iron-group elements (Cr, Mn, Fe, Co, and Ni). With
the realistic treatment of metal opacities up to the iron group in the
model-atmosphere calculations, the so-called Balmer-line problem (found in
models that neglect metal-line blanketing) vanishes.
Spectral analysis by means of NLTE model atmospheres has presently arrived at
a high level of sophistication, which is now hampered largely by the lack of
reliable atomic data and accurate line-broadening tables. Strong efforts should
be made to improve upon this situation.Comment: 13 pages, 20 figure
Water and ammonia abundances in S140 with the Odin satellite
We have used the Odin satellite to obtain strip maps of the ground-state
rotational transitions of ortho-water and ortho-ammonia, as well as CO(5-4) and
13CO(5-4) across the PDR, and H218O in the central position. A physi-chemical
inhomogeneous PDR model was used to compute the temperature and abundance
distributions for water, ammonia and CO. A multi-zone escape probability method
then calculated the level populations and intensity distributions. These
results are compared to a homogeneous model computed with an enhanced version
of the RADEX code. H2O, NH3 and 13CO show emission from an extended PDR with a
narrow line width of ~3 kms. Like CO, the water line profile is dominated by
outflow emission, however, mainly in the red wing. The PDR model suggests that
the water emission mainly arises from the surfaces of optically thick, high
density clumps with n(H2)>10^6 cm^-3 and a clump water abundance, with respect
to H2, of 5x10^-8. The mean water abundance in the PDR is 5x10^-9, and between
~2x10^-8 -- 2x10^-7 in the outflow derived from a simple two-level
approximation. Ammonia is also observed in the extended clumpy PDR, likely from
the same high density and warm clumps as water. The average ammonia abundance
is about the same as for water: 4x10^-9 and 8x10^-9 given by the PDR model and
RADEX, respectively. The similarity of water and ammonia PDR emission is also
seen in the almost identical line profiles observed close to the bright rim.
Around the central position, ammonia also shows some outflow emission although
weaker than water in the red wing. Predictions of the H2O(110-101) and
(111-000) antenna temperatures across the PDR are estimated with our PDR model
for the forthcoming observations with the Herschel Space Observatory.Comment: 13 pages, 14 figures, 10 tables. Accepted for publication in
Astronomy & Astrophysics 14 November 200
Docetaxel-Loaded PLGA Nanoparticles Improve Efficacy in Taxane-Resistant Triple-Negative Breast Cancer
Novel treatment strategies, including nanomedicine, are needed for improving management of triple-negative breast cancer. Patients with triple-negative breast cancer, when considered as a group, have a worse outcome after chemotherapy than patients with breast cancers of other subtypes, a finding that reflects the intrinsically adverse prognosis associated with the disease. The aim of this study was to improve the efficacy of docetaxel by incorporation into a novel nanoparticle platform for the treatment of taxane-resistant triple-negative breast cancer. Rod-shaped nanoparticles encapsulating docetaxel were fabricated using an imprint lithography based technique referred to as Particle Replication in Nonwetting Templates (PRINT). These rod-shaped PLGA-docetaxel nanoparticles were tested in the C3(1)-T-antigen (C3Tag) genetically engineered mouse model (GEMM) of breast cancer that represents the basal-like subtype of triple-negative breast cancer and is resistant to therapeutics from the taxane family. Thi..
Far infrared mapping of three Galactic star forming regions : W3(OH), S 209 & S 187
Three Galactic star forming regions associated with W3(OH), S209 and S187
have been simultaneously mapped in two trans-IRAS far infrared (FIR) bands
centered at ~ 140 and 200 micron using the TIFR 100 cm balloon borne FIR
telescope. These maps show extended FIR emission with structures. The HIRES
processed IRAS maps of these regions at 12, 25, 60 & 100 micron have also been
presented for comparison. Point-like sources have been extracted from the
longest waveband TIFR maps and searched for associations in the other five
bands. The diffuse emission from these regions have been quantified, which
turns out to be a significant fraction of the total emission. The spatial
distribution of cold dust (T < 30 K) for two of these sources (W3(OH) & S209),
has been determined reliably from the maps in TIFR bands. The dust temperature
and optical depth maps show complex morphology. In general the dust around S209
has been found to be warmer than that in W3(OH) region.Comment: Accepted for publication in Journal of Astrophysics and Astronomy (20
pages including 8 figures & 3 tables
- …