41,088 research outputs found
Research on the utilization of pattern recognition techniques to identify and classify objects in video data Technical progress report, 31 Jan. - 31 May 1967
Pattern recognition techniques for extracting information from video data and for reducing amount of data to convey this information - decision mechanisms and property filter
Explicit correlation and basis set superposition error: The structure and energy of carbon dioxide dimer
We have investigated the slipped parallel and t-shaped structures of carbon dioxide dimer [(CO₂)₂] using both conventional and explicitly correlated coupled cluster methods, inclusive and exclusive of counterpoise (CP) correction. We have determined the geometry of both structures with conventional coupled cluster singles doubles and perturbative triples theory [CCSD(T)] and explicitly correlated cluster singles doubles and perturbative triples theory [CCSD(T)-F12b] at the complete basis set (CBS) limits using custom optimization routines. Consistent with previous investigations, we find that the slipped parallel structure corresponds to the global minimum and is 1.09 kJ mol⁻¹ lower in energy. For a given cardinal number, the optimized geometries and interaction energies of (CO₂)₂ obtained with the explicitly correlated CCSD(T)-F12b method are closer to the CBS limit than the corresponding conventional CCSD(T) results. Furthermore, the magnitude of basis set superposition error (BSSE) in the CCSD(T)-F12b optimized geometries and interaction energies is appreciably smaller than the magnitude of BSSE in the conventional CCSD(T) results. We decompose the CCSD(T) and CCSD(T)-F12b interaction energies into the constituent HF or HF CABS, CCSD or CCSD-F12b, and (T) contributions. We find that the complementary auxiliary basis set (CABS) singles correction and the F12b approximation significantly reduce the magnitude of BSSE at the HF and CCSD levels of theory, respectively. For a given cardinal number, we find that non-CP corrected, unscaled triples CCSD(T)-F12b/VXZ-F12 interaction energies are in overall best agreement with the CBS limit
Long-term Recovery from Acute Cold Shock in Caenorhabditis Elegans
Background
Animals are exposed to a wide range of environmental stresses that can cause potentially fatal cellular damage. The ability to survive the period of stress as well as to repair any damage incurred is essential for fitness. Exposure to 2 °C for 24 h or longer is rapidly fatal to the nematode Caenorhabditis elegans, but the process of recovery from a shorter, initially non-lethal, cold shock is poorly understood.
Results We report that cold shock of less than 12-hour duration does not initially kill C. elegans, but these worms experience a progression of devastating phenotypes over the next 96 h that correlate with their eventual fate: successful recovery from the cold shock and survival, or failure to recover and death. Cold-shocked worms experience a marked loss of pigmentation, decrease in the size of their intestine and gonads, and disruption to the vulva. Those worms who will successfully recover from the cold shock regain their pigmentation and much of the integrity of their intestine and gonads. Those who will die do so with a distinct phenotype from worms dying during or immediately following cold shock, suggesting independent mechanisms. Worms lacking the G-protein coupled receptor FSHR-1 are resistant to acute death from longer cold shocks, and are more successful in their recovery from shorter sub-lethal cold shocks.
Conclusions We have defined two distinct phases of death associated with cold shock and described a progression of phenotypes that accompanies the course of recovery from that cold shock. The G-protein coupled receptor FSHR-1 antagonizes these novel processes of damage and recovery
Classical reflections on the deficit
Deficit financing ; Debt management ; Crowding out (Economics) ; Interest rates
Evaluating the Real Estate Journals: The Mainstream Finance Perspective
This study examines the real estate journals and discipline from the unique perspective of mainstream finance faculty. The entire academic membership of the Financial Management Association (FMA) is surveyed resulting in a 29.6% response rate. They were queried on their personal characteristics (enrollment, number of tenure track faculty, department, rank, area of expertise, number of articles published, and real estate courses offered). But more importantly, they were asked to rank real estate journals by perceived quality and to compare the quality of the real estate journals to five mainstream finance journals. Lastly, they were asked about the support for including real estate courses in the curriculum of the finance department.
Recommended from our members
Urspelerpes, U. brucei
Number of Pages: 3Integrative BiologyGeological Science
Viscous to Inertial Crossover in Liquid Drop Coalescence
Using an electrical method and high-speed imaging we probe drop coalescence
down to 10 ns after the drops touch. By varying the liquid viscosity over two
decades, we conclude that at sufficiently low approach velocity where
deformation is not present, the drops coalesce with an unexpectedly late
crossover time between a regime dominated by viscous and one dominated by
inertial effects. We argue that the late crossover, not accounted for in the
theory, can be explained by an appropriate choice of length-scales present in
the flow geometry.Comment: 4 pages, 4 figure
Multiple transient memories in sheared suspensions: robustness, structure, and routes to plasticity
Multiple transient memories, originally discovered in charge-density-wave
conductors, are a remarkable and initially counterintuitive example of how a
system can store information about its driving. In this class of memories, a
system can learn multiple driving inputs, nearly all of which are eventually
forgotten despite their continual input. If sufficient noise is present, the
system regains plasticity so that it can continue to learn new memories
indefinitely. Recently, Keim & Nagel showed how multiple transient memories
could be generalized to a generic driven disordered system with noise, giving
as an example simulations of a simple model of a sheared non-Brownian
suspension. Here, we further explore simulation models of suspensions under
cyclic shear, focussing on three main themes: robustness, structure, and
overdriving. We show that multiple transient memories are a robust feature
independent of many details of the model. The steady-state spatial distribution
of the particles is sensitive to the driving algorithm; nonetheless, the memory
formation is independent of such a change in particle correlations. Finally, we
demonstrate that overdriving provides another means for controlling memory
formation and retention
Multiple transient memories in experiments on sheared non-Brownian suspensions
A system with multiple transient memories can remember a set of inputs but
subsequently forgets almost all of them, even as they are continually applied.
If noise is added, the system can store all memories indefinitely. The
phenomenon has recently been predicted for cyclically sheared non-Brownian
suspensions. Here we present experiments on such suspensions, finding behavior
consistent with multiple transient memories and showing how memories can be
stabilized by noise.Comment: 5 pages, 4 figure
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