4,031 research outputs found
Universal power law behaviors in genomic sequences and evolutionary models
We study the length distribution of a particular class of DNA sequences known
as 5'UTR exons. These exons belong to the messanger RNA of protein coding
genes, but they are not coding (they are located upstream of the coding portion
of the mRNA) and are thus less constrained from an evolutionary point of view.
We show that both in mouse and in human these exons show a very clean power law
decay in their length distribution and suggest a simple evolutionary model
which may explain this finding. We conjecture that this power law behaviour
could indeed be a general feature of higher eukaryotes.Comment: 15 pages, 3 figure
Asymptotic Level Density of the Elastic Net Self-Organizing Feature Map
Whileas the Kohonen Self Organizing Map shows an asymptotic level density
following a power law with a magnification exponent 2/3, it would be desired to
have an exponent 1 in order to provide optimal mapping in the sense of
information theory. In this paper, we study analytically and numerically the
magnification behaviour of the Elastic Net algorithm as a model for
self-organizing feature maps. In contrast to the Kohonen map the Elastic Net
shows no power law, but for onedimensional maps nevertheless the density
follows an universal magnification law, i.e. depends on the local stimulus
density only and is independent on position and decouples from the stimulus
density at other positions.Comment: 8 pages, 10 figures. Link to publisher under
http://link.springer.de/link/service/series/0558/bibs/2415/24150939.ht
Culture of Intimidation: Power Relationships, Quiescence, and Rebellion in Oak Ridge, Tennessee
Studies suggest that quiescence, or the absence of challenge from deprived groups can be explained as a function of power relationships. Power has the potential to influence the decision-making process by monopolizing decision-making arenas. Furthermore, elites that occupy positions of power have the capability to resist challenges from deprived groups by preventing certain issues or grievances from ever being raised. This study’s focus is a former nuclear weapons production facility (the former K-25 Gaseous Diffusion Plant) in Oak Ridge, Tennessee, the quiescent nature of workers there, and the subsequent rise of rebellion. I employ a historical perspective using in-depth interviews and secondary data sources to investigate the perceptions of workers on power relationships. I explore the consequences of unequal power relationships on workers. K-25 was the first site built for the Manhattan Project in 1943. Findings indicate that the quiescent nature of K-25 workers cannot be explained by worker apathy or consensus with the status quo. In fact, the perception of quiescence can be explained by power relationships between dominant and subordinate groups. Generalized grievances were present, but were controlled and contained by the Department of Energy (DOE) and its corporate contractors. Even as rebellion emerged, traces of quiescence can still be found among workers in Oak Ridge
Capacitive pressure transducer system
Closed loop capacitive pressure transducer with extended frequency response for very low pressure measurement
Symposium: The 19th Amendment at 100: Citizen Soldiers and the Foundational Fusion of Masculinity, Citizenship, and Military Service
The Akron Law School’s conference on the 100th anniversary of the passage of the Nineteenth Amendment offered the chance to fight the eulogization of the Nineteenth Amendment and explore its modern relevance. This paper concludes that the Nineteenth Amendment cannot be understood without connecting it to broader conceptions of citizenship, masculinities, and military service, thus revealing its ongoing relevance to military inclusion and integration
A Solvable Sequence Evolution Model and Genomic Correlations
We study a minimal model for genome evolution whose elementary processes are
single site mutation, duplication and deletion of sequence regions and
insertion of random segments. These processes are found to generate long-range
correlations in the composition of letters as long as the sequence length is
growing, i.e., the combined rates of duplications and insertions are higher
than the deletion rate. For constant sequence length, on the other hand, all
initial correlations decay exponentially. These results are obtained
analytically and by simulations. They are compared with the long-range
correlations observed in genomic DNA, and the implications for genome evolution
are discussed.Comment: 4 pages, 4 figure
Parameter estimation in pair hidden Markov models
This paper deals with parameter estimation in pair hidden Markov models
(pair-HMMs). We first provide a rigorous formalism for these models and discuss
possible definitions of likelihoods. The model being biologically motivated,
some restrictions with respect to the full parameter space naturally occur.
Existence of two different Information divergence rates is established and
divergence property (namely positivity at values different from the true one)
is shown under additional assumptions. This yields consistency for the
parameter in parametrization schemes for which the divergence property holds.
Simulations illustrate different cases which are not covered by our results.Comment: corrected typo
Spontaneous dressed-state polarization in the strong driving regime of cavity QED
We utilize high-bandwidth phase quadrature homodyne measurement of the light
transmitted through a Fabry-Perot cavity, driven strongly and on resonance, to
detect excess phase noise induced by a single intracavity atom. We analyze the
correlation properties and driving-strength dependence of the atom-induced
phase noise to establish that it corresponds to the long-predicted phenomenon
of spontaneous dressed-state polarization. Our experiment thus provides a
demonstration of cavity quantum electrodynamics in the strong driving regime,
in which one atom interacts strongly with a many-photon cavity field to produce
novel quantum stochastic behavior.Comment: 4 pages, 4 color figure
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