Relationship between the direction of the interplanetary magnetic field and steady oscillation conditions

Effect of direction of interplanetary magnetic field on steady oscillation

Total coloring of 1-toroidal graphs of maximum degree at least 11 and no adjacent triangles

A {\em total coloring} of a graph $G$ is an assignment of colors to the vertices and the edges of $G$ such that every pair of adjacent/incident elements receive distinct colors. The {\em total chromatic number} of a graph $G$, denoted by \chiup''(G), is the minimum number of colors in a total coloring of $G$. The well-known Total Coloring Conjecture (TCC) says that every graph with maximum degree $\Delta$ admits a total coloring with at most $\Delta + 2$ colors. A graph is {\em $1$-toroidal} if it can be drawn in torus such that every edge crosses at most one other edge. In this paper, we investigate the total coloring of $1$-toroidal graphs, and prove that the TCC holds for the $1$-toroidal graphs with maximum degree at least~$11$ and some restrictions on the triangles. Consequently, if $G$ is a $1$-toroidal graph with maximum degree $\Delta$ at least~$11$ and without adjacent triangles, then $G$ admits a total coloring with at most $\Delta + 2$ colors.Comment: 10 page

Inverse spin-s portrait and representation of qudit states by single probability vectors

Using the tomographic probability representation of qudit states and the inverse spin-portrait method, we suggest a bijective map of the qudit density operator onto a single probability distribution. Within the framework of the approach proposed, any quantum spin-j state is associated with the (2j+1)(4j+1)-dimensional probability vector whose components are labeled by spin projections and points on the sphere. Such a vector has a clear physical meaning and can be relatively easily measured. Quantum states form a convex subset of the 2j(4j+3) simplex, with the boundary being illustrated for qubits (j=1/2) and qutrits (j=1). A relation to the (2j+1)^2- and (2j+1)(2j+2)-dimensional probability vectors is established in terms of spin-s portraits. We also address an auxiliary problem of the optimum reconstruction of qudit states, where the optimality implies a minimum relative error of the density matrix due to the errors in measured probabilities.Comment: 23 pages, 4 figures, PDF LaTeX, submitted to the Journal of Russian Laser Researc

Nanotechnology in Therapeutics: hydrogels and beyond

Nanotechnology in Therapeutics: Current Technology and Applications, Edited by Nicholas A. Peppas, J. Zach Hilt and J. Brock Thomas (Horizon Bioscience, 2007) contains seventeen chapters written by leading specialists in the field of polymeric materials for drug delivery and holds wealth of background as well as state of the art material divided into four sections: "Intelligent Therapeutics and Responsive Delivery Systems for Improved Absorption and Delivery", "Therapeutic Micro- and Nanodevices", "Nanostructured Therapeutic Materials" and "Nanoparticulate Systems in Intelligent Therapy". This newly published volume provides a stimulating read and a good point of reference to researchers wishing to explore the interdisciplinary fusion of nnanotechnology and medical therapeutics. The following gives brief summary and critically reviews the book

The Subtle Plague: Materialistic Visage of Neocolonialism and Its Consequences in Armah’s Fragments

This paper examines the materialistic visage of neocolonialism in Ayi KweiArmah’s Fragments. While neocolonialism is often seen in African leaders’role as stooges of the erstwhile colonial powers in order to perpetuatethemselves in office, this paper argues that the masses’ unbridled penchantfor foreign goods and life styles is itself another form of neocolonialism,albeit subtle. This paper not only sees this development as part of the “newrealism” which came in the wake of political independence but also positsthat the way forward in the continent may lie in nonconformity, itsrepercussions notwithstanding and a return to the way of production, humanrelationship and reciprocity as symbolized by the visionary Naana

An examination of risk allocation preferences in Public-Private Partnerships in Nigeria

Risk allocation preferences are important elements of Public-Private Partnerships (PPP), as the fundamental tension in many negotiations between the public and private sector in PPPs usually comes down to the  question: who is responsible for managing a particular risk? Yet research literature suggests that risk  allocation preferences phenomena have not been adequately studied; hence they remain poorly understood.  This paper provides an empirical analysis and study of risk allocation preferences in PPPs in Nigeria. Research participants (spanning banking, construction, and public sector groups who were selected through a convenience sampling method) completed an online survey with Likert-type items within six months (i.e.  between June and November 2011) to gauge probabilities of occurrence, risk impact and risk significance of 46 risk factors pertaining to PPP projects. As data did not meet the assumptions for parametric statistics,  Mann-Whitney U tests were performed to evaluate the ranked differences in the independent variables (46 risk factors) between private and public sector groups. This paper shows that 27 (59%) out of the 46 risk factors are preferred to be allocated to the private sector, while 8 (17%) risk factors are to be allocated to the public sector and 11 (24%) of the risk factors are to be equally shared between the private and public sectors.Key words: Risk Allocation Preferences, Nigeria, Agency Theory, Public-Private Partnerships, and Mann-Whitney U tests

Applications of nanoparticles in biology and medicine

Nanomaterials are at the leading edge of the rapidly developing field of nanotechnology. Their unique size-dependent properties make these materials superior and indispensable in many areas of human activity. This brief review tries to summarise the most recent developments in the field of applied nanomaterials, in particular their application in biology and medicine, and discusses their commercialisation prospects

p38α (MAPK14) critically regulates the immunological response and the production of specific cytokines and chemokines in astrocytes.

In CNS lesions, "reactive astrocytes" form a prominent cellular response. However, the nature of this astrocyte immune activity is not well understood. In order to study astrocytic immune responses to inflammation and injury, we generated mice with conditional deletion of p38α (MAPK14) in GFAP+ astrocytes. We studied the role of p38α signaling in astrocyte immune activation both in vitro and in vivo, and simultaneously examined the effects of astrocyte activation in CNS inflammation. Our results showed that specific subsets of cytokines (TNFα, IL-6) and chemokines (CCL2, CCL4, CXCL1, CXCL2, CXCL10) are critically regulated by p38α signaling in astrocytes. In an in vivo CNS inflammation model of intracerebral injection of LPS, we observed markedly attenuated astrogliosis in conditional GFAPcre p38α(-/-) mice. However, GFAPcre p38α(-/-) mice showed marked upregulation of CCL2, CCL3, CCL4, CXCL2, CXCL10, TNFα, and IL-1β compared to p38αfl/fl cohorts, suggesting that in vivo responses to LPS after GFAPcre p38α deletion are complex and involve interactions between multiple cell types. This finding was supported by a prominent increase in macrophage/microglia and neutrophil recruitment in GFAPcre p38α(-/-) mice compared to p38αfl/fl controls. Together, these studies provide important insights into the critical role of p38α signaling in astrocyte immune activation