1,567 research outputs found
Multidimensional Dynamical Systems Accepting the Normal Shift
The dynamical systems of the form \ddot\bold r=\bold F (\bold r,\dot\bold
r) in accepting the normal shift are considered. The concept of
weak normality for them is introduced. The partial differential equations for
the force field \bold F(\bold r,\dot\bold r) of the dynamical systems with
weak and complete normality are derived.Comment: AMS-TeX, ver. 2.1, IBM AT-386, size 16K (ASCII), short versio
NF-{kappa}B-dependent induction of microRNA miR-146, an inhibitor targeted to signaling proteins of innate immune responses
Activation of mammalian innate and acquired immune responses must be tightly regulated by elaborate mechanisms to control their onset and termination. MicroRNAs have been implicated as negative regulators controlling diverse biological processes at the level of posttranscriptional repression. Expression profiling of 200 microRNAs in human monocytes revealed that several of them (miR-146a/b, miR-132, and miR-155) are endotoxin-responsive genes. Analysis of miR-146a and miR-146b gene expression unveiled a pattern of induction in response to a variety of microbial components and proinflammatory cytokines. By means of promoter analysis, miR-146a was found to be a NF-{kappa}B-dependent gene. Importantly, miR-146a/b were predicted to base-pair with sequences in the 3' UTRs of the TNF receptor-associated factor 6 and IL-1 receptor-associated kinase 1 genes, and we found that these UTRs inhibit expression of a linked reporter gene. These genes encode two key adapter molecules downstream of Toll-like and cytokine receptors. Thus, we propose a role for miR-146 in control of Toll-like receptor and cytokine signaling through a negative feedback regulation loop involving down-regulation of IL-1 receptor-associated kinase 1 and TNF receptor-associated factor 6 protein levels
Analysis of Spin Polarization in Half-Metallic Heusler Alloys
Half-metals have recently gained great interest in the field of spintronics because their 100% spin polarization may make them an ideal current source for spintronic devices. This project examines four Heusler Alloys of the form Co2FexMn1−xSi that are expected to be half-metallic. Two magnetic properties of these alloys were examined, the Anisotropic Magnetoresistance (AMR) and the Anomalous Hall Effect (AHE). These properties have the potential to be used as simple and fast ways to identify materials as half-metallic or non-half-metallic. The results of these measurements were also used to examine the spin polarization and other properties of these materials
Evolutionary suicide through a non-catastrophic bifurcation : adaptive dynamics of pathogens with frequency-dependent transmission
Evolutionary suicide is a riveting phenomenon in which adaptive evolution drives a viable population to extinction. Gyllenberg and Parvinen (Bull Math Biol 63(5):981-993, 2001) showed that, in a wide class of deterministic population models, a discontinuous transition to extinction is a necessary condition for evolutionary suicide. An implicit assumption of their proof is that the invasion fitness of a rare strategy is well-defined also in the extinction state of the population. Epidemic models with frequency-dependent incidence, which are often used to model the spread of sexually transmitted infections or the dynamics of infectious diseases within herds, violate this assumption. In these models, evolutionary suicide can occur through a non-catastrophic bifurcation whereby pathogen adaptation leads to a continuous decline of host (and consequently pathogen) population size to zero. Evolutionary suicide of pathogens with frequency-dependent transmission can occur in two ways, with pathogen strains evolving either higher or lower virulence.Peer reviewe
Becoming Transcultural: Filling The Cultural And Communication Gap Within The Black American Community
The purpose of this study is to define transculturalism by exploring the Black experience through collectivism/individualism, Black identity and the ability to be transcultural. The study included 83 male and female Black American, college students, graduate students and college graduates. The participants answered a 4-part survey that measured collectivism/individualism, Black identity, the ability to be transcultural and minority hardships. Results revealed that the Pre-encounter, Immersion, Emersion and Internalization phases of Black identity are predictors of minority hardships. There were also significant results for the Internalization phase of Black identity and the ability to be transcultural. In conclusion, Black Americans that are secure with their identity have the ability to become transcultural
Зубелевич Я. Аксиоцентризм в философии образования
Рецензія на монографію: Зубелевич Я. Аксиоцентризм в философии образования / пер. с польского О. Гирного ; Ян Зубелевич. – СПб. : Изд-во Политех. ун-та, 2008. – 220 с
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