2,451 research outputs found
Potential Barrier Classification by Short-Time Measurement
We investigate the short-time dynamics of a delta-function potential barrier
on an initially confined wave-packet. There are mainly two conclusions: A) At
short times the probability density of the first particles that passed through
the barrier is unaffected by it. B) When the barrier is absorptive (i.e., its
potential is imaginary) it affects the transmitted wave function at shorter
times than a real potential barrier. Therefore, it is possible to distinguish
between an imaginary and a real potential barrier by measuring its effect at
short times only on the transmitting wavefunction.Comment: 6 pages, 5 figure
Survival of Terrestrial Planets in the Presence of Giant Planet Migration
The presence of ``Hot Jupiters'', Jovian mass planets with very short orbital
periods orbiting nearby main sequence stars, has been proposed to be primarily
due to the orbital migration of planets formed in orbits initially much further
from the parent star. The migration of giant planets would have profound
effects on the evolution of inner terrestrial planets in these systems, and
previous analyses have assumed that no terrestrial planets survive after
migration has occurred. We present numerical simulations showing that a
significant fraction of terrestrial planets could survive the migration
process, eventually returning to circular orbits relatively close to their
original positions. A fraction of the final orbits are in the Habitable Zone,
suggesting that planetary systems with close-in giant planets are viable
targets for searches for Earth-like habitable planets around other stars.Comment: 5 pages, 3 figures, emulateapj. ApJL in press, referee comments
changes and edited for lengt
Genes2Networks: Connecting Lists of Proteins by Using Background Literature-based Mammalian Networks
In recent years, in-silico literature-based mammalian protein-protein interaction network datasets have been developed. These datasets contain binary interactions extracted manually from legacy experimental biomedical research literature. Placing lists of genes or proteins identified as significantly changing in multivariate experiments, in the context of background knowledge about binary interactions, can be used to place these genes or proteins in the context of pathways and protein complexes.
Genes2Networks is a software system that integrates the content of ten mammalian literature-based interaction network datasets. Filtering to prune low-confidence interactions was implemented. Genes2Networks is delivered as a web-based service using AJAX. The system can be used to extract relevant subnetworks created from “seed” lists of human Entrez gene names. The output includes a dynamic linkable three color web-based network map, with a statistical analysis report that identifies significant intermediate nodes used to connect the seed list. Genes2Networks is available at http://actin.pharm.mssm.edu/genes2networks.
Genes2Network is a powerful web-based software application tool that can help experimental biologists to interpret high-throughput experimental results used in genomics and proteomics studies where the output of these experiments is a list of significantly changing genes or proteins. The system can be used to find relationships between nodes from the seed list, and predict novel nodes that play a key role in a common function
Control of Four-Level Quantum Coherence via Discrete Spectral Shaping of an Optical Frequency Comb
We present an experiment demonstrating high-resolution coherent control of a
four-level atomic system in a closed (diamond) type configuration. A
femtosecond frequency comb is used to establish phase coherence between a pair
of two-photon transitions in cold Rb atoms. By controlling the spectral phase
of the frequency comb we demonstrate the optical phase sensitive response of
the diamond system. The high-resolution state selectivity of the comb is used
to demonstrate the importance of the signs of dipole moment matrix elements in
this type of closed-loop excitation. Finally, the pulse shape is optimized
resulting in a 256% increase in the two-photon transition rate by forcing
constructive interference between the mode pairs detuned from an intermediate
resonance.Comment: 5 pages, 4 figures Submitted to Physical Review Letter
Problems in the Re-classification of the Balance Sheet as Part of an Integrated Information System
The integrated information system is an IT and information structure that includes financial reporting and management control analysis. This system requires that each accounting item is linked to every other object. In the integrated information system, it is also necessary that each item has a unique meaning. Therefore, it is impossible to have several implications or several accounting items with special meanings.
The reclassification of the balance sheet in an integrated information system requires the adoption of an extraordinarily complete and exhaustive scheme. All this is indispensable for implementing a balance sheet/budget analysis that can be useful to company management for the implementation of a decision-making process that maximises management and decision-making efficiency and effectiveness.
The correct reclassification of all balance sheet and financial items sometimes requires reasoning that does not always appear linear and straightforward. For this reason, in the following pages, we will analyse the balance sheet items that, in general, are the precursors of reclassification errors that can invalidate the entire analysis of the balance sheet and the balance sheet budget
A Comprehensive Administrative Solution to the Armed Career Criminal Act Debacle
For thirty years, the Armed Career Criminal Act (“ACCA”) has imposed a fifteen-year mandatory minimum sentence on those people convicted as felons in possession of a firearm or ammunition who have three prior convictions for a violent felony or serious drug offense. Debate about the law has existed mainly within a larger discussion on the normative value of mandatory minimums. Assuming that the ACCA endures, however, administering it will continue to be a challenge. The approach that courts use to determine whether past convictions qualify as ACCA predicate offenses creates ex ante uncertainty and the potential for intercourt disparities. Furthermore, the Supreme Court’s guidance on sentencing ACCA defendants has been unclear. The resulting ambiguity creates inequity between defendants and fails to give them fair warning of the statute’s scope. This ambiguity also depletes the resources of courts, defendants, and prosecutors and prevents the statute from realizing its full potential of deterring violent crime. This Note argues that rather than allowing this debacle to continue, Congress should delegate to a federal agency the task of compiling a binding list of state statutes that qualify as predicate offenses. Under this approach, the states would assist the federal agency by providing initial guidance on their ambiguous statutes. The U.S. Sentencing Commission has the manpower, subject familiarity, and institutional incentives to build and maintain the appendix, and state sentencing commissions would make ideal partners. In states that do not have sentencing commissions, comparable agencies and even properly incentivized attorneys general may be able to aid the federal Sentencing Commission. Congress should leverage this undertaking to resolve related definitional questions about the meaning of a violent crime in other areas of federal law
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