4,972 research outputs found
HD101584: Circumstellar characteristics and evolutionary status
We have performed a study of the characteristics of the circumstellar
environment of the binary object HD101584, that provides information on a
likely evolutionary scenario. We have obtained and analysed ALMA observations,
complemented with observations using APEX, of a large number of molecular
lines. An analysis of the spectral energy distribution has also been performed.
Emissions from 12 molecular species (not counting isotopologues) have been
observed, and most of them mapped with angular resolutions in the range 0.1" to
0.6". Four circumstellar components are identified: i) a central compact source
of size 0.15", ii) an expanding equatorial density enhancement (a flattened
density distribution in the plane of the orbit) of size 3", iii) a bipolar
high-velocity outflow (150 km/s), and iv) an hourglass structure. The outflow
is directed almost along the line of sight. There is evidence of a second
bipolar outflow. The mass of the circumstellar gas is 0.5[D/1 kpc]^2 Msun,
about half of it lies in the equatorial density enhancement. The dust mass is
0.01[D/1 kpc]^2 Msun, and a substantial fraction of this is in the form of
large-sized, up to 1 mm, grains. The estimated kinetic age of the outflow is
770[D/1 kpc] yr. The kinetic energy and the scalar momentum of the accelerated
gas are estimated to be 7x10^(45)[D/1 kpc]^2 erg and 10^(39)[D/1 kpc]^2 g cm/s,
respectively. We provide good evidence that the binary system HD101584 is in a
post-common-envelope-evolution phase, that ended before a stellar merger.
Isotope ratios combined with stellar mass estimates suggest that the primary
star's evolution was terminated already on the first red giant branch (RGB).
Most of the energy required to drive the outflowing gas was probably released
when material fell towards the companion.Comment: Accepted for publication in A&
Variation of hydraulic properties due to dynamic fracture damage: Implications for fault zones
High strain rate loading causes pervasive dynamic microfracturing in crystalline materials,
with dynamic pulverization being the extreme end-member. Hydraulic properties (permeability,
porosity, and storage capacity) are primarily controlled by fracture damage and will therefore change
significantly by intense dynamic fracturingâby how much is currently unknown. Dynamic fracture
damage observed in the damage zones of seismic faults is thought to originate from dynamic stresses near
the earthquake rupture tip. This implies that during an earthquake, hydraulic properties in the damage
zone change early. The immediate effect this has on fluid-driven coseismic slip processes following the
rupture, and on postseismic and interseismic fault zone processes, is not yet clear. Here, we present
hydraulic properties measured on the full range of dynamic fracture damage up to dynamic pulverization.
Dynamic damage was induced in quartz-monzonite samples by performing uniaxial high strain rate
(> 100 sâ1) experiments in compression using a split-Hopkinson pressure bar. Hydraulic properties were
measured on samples subjected to single and successive loadings, the latter to simulate cumulative damage
from repeated rupture events. We show that permeability increases by 6 orders of magnitude and porosity
by 15% with dissipated energy up to dynamic pulverization, for both single and successive loadings. We
present damage zone permeability profiles induced by earthquake rupture and how it evolves with
repeated ruptures. We propose that the enhanced hydraulic properties measured for pulverized rock
decrease the efficiency of thermal pressurization, when emplaced adjacent to the principal slip zone
Achieving sub-diffraction imaging through bound surface states in negative-refracting photonic crystals at the near-infrared
We report the observation of imaging beyond the diffraction limit due to
bound surface states in negative refraction photonic crystals. We achieve an
effective negative index figure-of-merit [-Re(n)/Im(n)] of at least 380, ~125x
improvement over recent efforts in the near-infrared, with a 0.4 THz bandwidth.
Supported by numerical and theoretical analyses, the observed near-field
resolution is 0.47 lambda, clearly smaller than the diffraction limit of 0.61
lambda. Importantly, we show this sub-diffraction imaging is due to the
resonant excitation of surface slab modes, allowing refocusing of
non-propagating evanescent waves
LNK (SH2B3): paradoxical effects in ovarian cancer.
LNK (SH2B3) is an adaptor protein studied extensively in normal and malignant hematopoietic cells. In these cells, it downregulates activated tyrosine kinases at the cell surface resulting in an antiproliferative effect. To date, no studies have examined activities of LNK in solid tumors. In this study, we found by in silico analysis and staining tissue arrays that the levels of LNK expression were elevated in high-grade ovarian cancer. To test the functional importance of this observation, LNK was either overexpressed or silenced in several ovarian cancer cell lines. Remarkably, overexpression of LNK rendered the cells resistant to death induced by either serum starvation or nutrient deprivation, and generated larger tumors using a murine xenograft model. In contrast, silencing of LNK decreased ovarian cancer cell growth in vitro and in vivo. Western blot studies indicated that overexpression of LNK upregulated and extended the transduction of the mitogenic signal, whereas silencing of LNK produced the opposite effects. Furthermore, forced expression of LNK reduced cell size, inhibited cell migration and markedly enhanced cell adhesion. Liquid chromatography-mass spectroscopy identified 14-3-3 as one of the LNK-binding partners. Our results suggest that in contrast to the findings in hematologic malignancies, the adaptor protein LNK acts as a positive signal transduction modulator in ovarian cancers
Decision making dynamics within the Vietnamese family unit
The Vietnamese family is changing and so may be the way they make mid-to-high involvement consumer decisions. A dynamic economy, rising standards of living, and an increasingly consumption-oriented society are changing the way families interact, especially about consumption. The traditional belief that the big decisions are made by the paternal head of family is no longer the norm. In some cases the household head is switching from the eldest male to the main salary earner. There are also smaller nuclear family households with fewer children. With increasing education levels of younger generations and changing family dynamics, the possibility of increased reciprocal consumer socialisation occurring is likely
Comparing drug-using behaviors among high school graduates entering military service, college, and civilian employment
https://deepblue.lib.umich.edu/bitstream/2027.42/137885/1/occ42.pd
An introduction to crowdsourcing for language and multimedia technology research
Language and multimedia technology research often relies on
large manually constructed datasets for training or evaluation of algorithms and systems. Constructing these datasets is often expensive with significant challenges in terms of recruitment of personnel to carry out the work. Crowdsourcing methods using scalable pools of workers available on-demand offers a flexible means of rapid low-cost construction of many of these datasets to support existing research requirements and potentially promote new research initiatives that would otherwise not be possible
The Monitoring the Future 8th Grade Panel Survey Data: Sample Design, Adjustments for Panel Attrition Biases, and Assessment of Measurement Bias
https://deepblue.lib.umich.edu/bitstream/2027.42/137871/1/occ55.pd
Revisiting marriage effects on substance use among young adults
https://deepblue.lib.umich.edu/bitstream/2027.42/137855/1/occ68.pd
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