206 research outputs found
Exact moments in a continuous time random walk with complete memory of its history
We present a continuous time generalization of a random walk with complete
memory of its history [Phys. Rev. E 70, 045101(R) (2004)] and derive exact
expressions for the first four moments of the distribution of displacement when
the number of steps is Poisson distributed. We analyze the asymptotic behavior
of the normalized third and fourth cumulants and identify new transitions in a
parameter regime where the random walk exhibits superdiffusion. These
transitions, which are also present in the discrete time case, arise from the
memory of the process and are not reproduced by Fokker-Planck approximations to
the evolution equation of this random walk.Comment: Revtex4, 10 pages, 2 figures. v2: applications discussed, clarity
improved, corrected scaling of third momen
Philippine employment in the seventies
One of the most important development challenges that confronts
the Philippines in the years ahead is the need to provide jobs
to the currently unemployed and underemployed members of the
labor force as well as to the 600,000_650,000 persons who join the
labor force every year. Accordingly, employment promotion remains
a high priority in our country's total development efforts.
This study on Philippine employment in the seventies by Rosa
Linda P. Tidalgo and Emmanuel F. Esguerra presents valuable information
and insights on the Philippine employment scenario. It
reviews the findings and recommendations of employment research,
highlights the employment experience in the 70's, evaluates the overall
policy framework for employment promotion, assesses the state
of Philippine employment statistics,and indicates the factors which
should be considered in formulating employment policy. The problems
identified in the study, e.g., the capital-bias promoted by the
structure of economic incentives and pattern of industrialization; the
failure of the industrial sector to absorb labor from agriculture; the
need for timely and accurate information on employment; and the
need to harmonize employment policies with other development
policies, do not require further emphasis.Certainly, sustained national
development depends a great deal on how these problems are
approached and resolved.
It is hoped that this study can in one way or another assist in
promoting more effective and consistent employment policies and
programs in the future
Brownian motion of a charged particle driven internally by correlated noise
We give an exact solution to the generalized Langevin equation of motion of a
charged Brownian particle in a uniform magnetic field that is driven internally
by an exponentially-correlated stochastic force. A strong dissipation regime is
described in which the ensemble-averaged fluctuations of the velocity exhibit
transient oscillations that arise from memory effects. Also, we calculate
generalized diffusion coefficients describing the transport of these particles
and briefly discuss how they are affected by the magnetic field strength and
correlation time. Our asymptotic results are extended to the general case of
internal driving by correlated Gaussian stochastic forces with finite
autocorrelation times.Comment: 10 pages, 4 figures with subfigures, RevTeX, v2: revise
A tale of two concessionaires: A natural experiment of water privatisation in Metro Manila
10.1177/0042098007085108Urban Studies451207-22
A circular RNA generated from an intron of the insulin gene controls insulin secretion.
Fine-tuning of insulin release from pancreatic β-cells is essential to maintain blood glucose homeostasis. Here, we report that insulin secretion is regulated by a circular RNA containing the lariat sequence of the second intron of the insulin gene. Silencing of this intronic circular RNA in pancreatic islets leads to a decrease in the expression of key components of the secretory machinery of β-cells, resulting in impaired glucose- or KCl-induced insulin release and calcium signaling. The effect of the circular RNA is exerted at the transcriptional level and involves an interaction with the RNA-binding protein TAR DNA-binding protein 43 kDa (TDP-43). The level of this circularized intron is reduced in the islets of rodent diabetes models and of type 2 diabetic patients, possibly explaining their impaired secretory capacity. The study of this and other circular RNAs helps understanding β-cell dysfunction under diabetes conditions, and the etiology of this common metabolic disorder
A circular RNA generated from an intron of the insulin gene controls insulin secretion
Fine-tuning of insulin release from pancreatic β-cells is essential to maintain blood glucose homeostasis. Here, we report that insulin secretion is regulated by a circular RNA containing the lariat sequence of the second intron of the insulin gene. Silencing of this intronic circular RNA in pancreatic islets leads to a decrease in the expression of key components of the secretory machinery of β-cells, resulting in impaired glucose- or KCl-induced insulin release and calcium signaling. The effect of the circular RNA is exerted at the transcriptional level and involves an interaction with the RNA-binding protein TAR DNA-binding protein 43 kDa (TDP-43). The level of this circularized intron is reduced in the islets of rodent diabetes models and of type 2 diabetic patients, possibly explaining their impaired secretory capacity. The study of this and other circular RNAs helps understanding β-cell dysfunction under diabetes conditions, and the etiology of this common metabolic disorder
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