447 research outputs found
Level Crossing Analysis of the Stock Markets
We investigate the average frequency of positive slope ,
crossing for the returns of market prices.
The method is based on stochastic processes which no scaling feature is
explicitly required. Using this method we define new quantity to quantify stage
of development and activity of stocks exchange. We compare the Tehran and
western stock markets and show that some stocks such as Tehran (TEPIX) and New
Zealand (NZX) stocks exchange are emerge, and also TEPIX is a non-active market
and financially motivated to absorb capital.Comment: 6 pages and 4 figure
Level Crossing Analysis of Burgers Equation in 1+1 Dimensions
We investigate the average frequency of positive slope ,
crossing the velocity field in the Burgers equation.
The level crossing analysis in the inviscid limit and total number of positive
crossing of velocity field before creation of singularities are given. The main
goal of this paper is to show that this quantity, , is a good
measure for the fluctuations of velocity fields in the Burgers turbulence.Comment: 5 pages, 3 figure
Overexpression of microRNA-16 declines cellular growth, proliferation and induces apoptosis in human breast cancer cells
MicroRNAs (miRNA) are a large family of small single-stranded RNA molecules found in all multicellular organisms. Early studies have been shown that miRNA are involved in cancer development and progression, and this role can be done by working as an oncogenes and tumor suppressor genes, so manipulation of this molecules can be a promising approach in cancer therapy, and experimental results represented that the modification in breast cancer phenotype is possible by miRNA expression alteration. miR-16, which is located in 13q14 chromosome, plays critical roles as a tumor suppressor by targeting several oncogenes which regulate cell cycle and apoptosis. Hence, in the present study, we investigated whether miR-16 could decline growth and survival of MCF-7 cell line as model of human breast cancer. MCF-7 cell line was infected with lentiviruses containing miR-16 precursor sequence. The effects of ectopic expression of miR-16 on breast cancer phenotype were examined by cell cycle analysis and apoptosis assays. miR-16 cytotoxicity effect was measured by the MTT assay. We showed that the miR-16 overexpression reduces Cyclin D1 and BCL2 at messenger RNA (mRNA) and protein levels in MCF-7 cell line. In addition, this is found that enforced expression of miR-16 decreases cell growth and proliferation and induces apoptosis in MCF-7 cells. In conclusion, our results revealed that upregulation of miR-16 would be a potential approach for breast cancer therapy. © 2015, The Society for In Vitro Biology
Use of Antihypertensive Drugs during Pregnancy and Lactation
The decision to treat elevated arterial pressure in pregnancy depends on the risk and benefits imposed on the mother and the fetus. Treatment for mildto-moderate hypertension during pregnancy may not reduce maternal or fetal risk. Severe hypertension, on the other hand, should be treated to decrease maternal risk. Methyldopa and β-adrenoceptor antagonists have been used most extensively. In acute severe hypertension, intravenous labetalol or oral nifedipine are reasonable choices
Apego y emociones en la niñez media y adolescencia
The purpose of this review is to summarize and evaluate the current state of the literature with regards to attachment and its relationship to emotion in middle childhood and adolescence. This is a relatively new topic of interest and one which is well grounded in theory. The attachment relationship between parents and children is a key mechanism by which children and adolescents learn emotion skills, including emotion understanding, coping strategies, and how to manage different affective experiences. The review is organized by emotion domain, including emotion understanding, affective experiences, physiological indicators of arousal and emotion, and processes for the regulation of emotion. We included studies which presented data for children and adolescents ages 6-18, and included measures of emotion and parent-child attachment. Although some areas have been investigated more than others, we found that secure attachment was related to more adaptive functioning in each of the emotion domains. Finally, we review future directions to be explored and address gaps in the current literature.El propósito de este análisis es resumir y evaluar es estado actual de la literatura con respecto al apego y su relación con emociones en la niñez media y adolescencia. Este es un tema de interés relativamente nuevo y con buenos conocimientos teóricos. La relación de apego entre los padres y los hijos es el mecanismo clave a través del cual los hijos y adolescentes aprenden destrezas emocionales, incluido entendimiento emocional, estrategias de afrontamiento y cómo manejar diferentes experiencias afectivas. El análisis es organizado según las competencias emocionales, incluido entendimiento emocional, experiencias afectivas, indicadores fisiológicos de excitación y emociones, y procesos para la regulación de emociones. Hemos incluido estudios que presentan datos para niños y adolescentes de entre 6 y 18 años, y también medidas de emociones y apego padres-hijos. Aunque algunos campos fueron investigados mejor que otros, nosotros hemos comprobado que el apego seguro está relacionado con el funcionamiento más adaptado en cada uno de dominios emocionales. Finalmente, analizamos las direcciones futuras que están por explorar y abordamos los huecos en la literatura presente
Multifractal analysis of stress time series during ultrathin lubricant film melting
Melting of an ultrathin lubricant film confined between two atomically flat
surfaces is we studied using the rheological model for viscoelastic matter
approximation. Phase diagram with domains, corresponding to sliding, dry, and
two types of friction regimes has been built taking into account
additive noises of stress, strain, and temperature of the lubricant. The stress
time series have been obtained for all regimes of friction using the
Stratonovich interpretation. It has been shown that self-similar regime of
lubricant melting is observed when intensity of temperature noise is much
larger than intensities of strain and stress noises. This regime is defined by
homogenous distribution, at which characteristic stress scale is absent. We
study stress time series obtained for all friction regimes using multifractal
detrended fluctuation analysis. It has been shown that multifractality of these
series is caused by different correlations that are present in the system and
also by a power-law distribution. Since the power-law distribution is related
to small stresses, this case corresponds to self-similar solid-like lubricant.Comment: 22 pages, 10 figures, 41 reference
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