14,246 research outputs found
Seasonal sea surface temperature variations in the Persian Gulf as recorded by Nimbus 2 HRIR
Seasonal sea surface temperature variations in Persian Gulf recorded by Nimbus 2 HRI
Scale-Dependent Price Fluctuations for the Indian Stock Market
Classic studies of the probability density of price fluctuations for
stocks and foreign exchanges of several highly developed economies have been
interpreted using a {\it power-law} probability density function with exponent values , which are outside the
L\'evy-stable regime . To test the universality of this
relationship for less highly developed economies, we analyze daily returns for
the period Nov. 1994--June 2002 for the 49 largest stocks of the National Stock
Exchange which has the highest volume of trade in India. We find that
decays as an {\it exponential} function with a
characteristic decay scales for the negative tail and
for the positive tail, which is significantly different
from that observed for developed economies. Thus we conclude that the Indian
stock market may belong to a universality class that differs from those of
developed countries analyzed previously.Comment: 7 pages, 8 figure
Dynamic polarization of graphene by moving external charges: random phase approximation
We evaluate the stopping and image forces on a charged particle moving
parallel to a doped sheet of graphene by using the dielectric response
formalism for graphene's -electron bands in the random phase approximation
(RPA). The forces are presented as functions of the particle speed and the
particle distance for a broad range of charge-carrier densities in graphene. A
detailed comparison with the results from a kinetic equation model reveal the
importance of inter-band single-particle excitations in the RPA model for high
particle speeds. We also consider the effects of a finite gap between graphene
and a supporting substrate, as well as the effects of a finite damping rate
that is included through the use of Mermin's procedure. The damping rate is
estimated from a tentative comparison of the Mermin loss function with a HREELS
experiment. In the limit of low particle speeds, several analytical results are
obtained for the friction coefficient that show an intricate relationship
between the charge-carrier density, the damping rate, and the particle
distance, which may be relevant to surface processes and electrochemistry
involving graphene.Comment: 14 pages, 10 figures, accepted for publication in Phys. Rev.
Has Affirmative Action Been Negated? A Closer Look at Public Employment
First, this Article argues that affirmative action is right and necessary in certain circumstances. Second, it examines whether affirmative action has survived under current case law. Part II.A reviews the Supreme Court decisions that define the test of strict scrutiny in the public employment context. Part II.B discusses the current focus of the Court\u27s debate on affirmative action. Part III looks at how strict scrutiny analysis and the Supreme Court\u27s precedents are being applied by the lower federal courts. Part IV concludes that more guidance is needed from the Supreme Court on the first prong of the strict scrutiny analysis as to when a compelling government interest exists. Last, this Article suggests that the Supreme Court firmly establish an inferential standard for proving past discrimination by a public employer sufficient to warrant current affirmative action
Guest Editors’ Introduction to the FIRE Special Issue on “The Place and Future of Comparative Education in Teacher Education”
Guest Editors’ Introduction to the FIRE Special Issue on “The Place and Future of Comparative Education in Teacher Education”
Parrondo-like behavior in continuous-time random walks with memory
The Continuous-Time Random Walk (CTRW) formalism can be adapted to encompass
stochastic processes with memory. In this article we will show how the random
combination of two different unbiased CTRWs can give raise to a process with
clear drift, if one of them is a CTRW with memory. If one identifies the other
one as noise, the effect can be thought as a kind of stochastic resonance. The
ultimate origin of this phenomenon is the same of the Parrondo's paradox in
game theoryComment: 8 pages, 3 figures, revtex; enlarged and revised versio
Men and women from the STRIDE clinical trial: An assessment of stimulant abstinence symptom severity at residential treatment entry
Background and Objectives
Gender‐specific factors associated with stimulant abstinence severity were examined in a stimulant abusing or dependent residential treatment sample (N = 302). Method
Bivariate statistics tested gender differences in stimulant abstinence symptoms, measured by participant‐reported experiences of early withdrawal. Multivariate linear regression examined gender and other predictors of stimulant abstinence symptom severity. Results
Women compared to men reported greater stimulant abstinence symptom severity. Anxiety disorders and individual anxiety‐related abstinence symptoms accounted for this difference. African American race/ethnicity was predictive of lower stimulant abstinence severity. Discussion and Conclusions
Women were more sensitive to anxiety‐related stimulant withdrawal symptoms. Scientific Significance
Clinics that address anxiety‐related abstinence symptoms, which more commonly occur in women, may improve treatment outcome. (Am J Addict 2015;XX:XX –XX
Cell shape change and invagination of the cephalic furrow involves reorganization of F-actin
AbstractInvagination of epithelial sheets to form furrows is a fundamental morphogenetic movement and is found in a variety of developmental events including gastrulation and vertebrate neural tube formation. The cephalic furrow is a deep epithelial invagination that forms during Drosophila gastrulation. In the first phase of cephalic furrow formation, the initiator cells that will lead invagination undergo apicobasal shortening and apical constriction in the absence of epithelial invagination. In the second phase of cephalic furrow formation, the epithelium starts to invaginate, accompanied by both basal expansion and continued apicobasal shortening of the initiator cells. The cells adjacent to the initiator cells also adopt wedge shapes, but only after invagination is well underway. Myosin II does not appear to drive apical constriction in cephalic furrow formation. However, cortical F-actin is increased in the apices of the initiator cells and in invaginating cells during both phases of cephalic furrow formation. These findings suggest that a novel mechanism for epithelial invagination is involved in cephalic furrow formation
Multiple roles for membrane-associated protein trafficking and signaling in gravitropism
Gravitropism is a process that allows plant organs to guide their growth relative to the gravity vector. It requires them to sense changes in their orientation and generate a biochemical signal that they transmit to the tissues that drive organ curvature. Trafficking between the plasma membrane and endosomal compartments is important for all of these phases of the gravitropic response. The sedimentation of starch-filled organelles called amyloplasts plays a key role in sensing reorientation, and vacuolar integrity is required for amyloplast sedimentation in shoots. Other proteins associated with the vesicle trafficking pathway contribute to early gravity signal transduction independently of amyloplast sedimentation in both roots and hypocotyls. Phosphatidylinositol signaling, which starts at the plasma membrane and later affects the localization of auxin efflux facilitators, is a likely second messenger in the signal transduction phase of gravitropism. Finally, membrane-localized auxin influx and efflux facilitators contribute to a differential auxin gradient across the gravistimulated organs, which directs root curvature
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