Empirical modeling of the quiet time nightside magnetosphere

Empirical modeling of plasma pressure and magnetic field for the quiet time nightside magnetosphere is investigated. Two models are constructed for this study. One model, referred to here as T89R, is basically the magnetic field model of Tsyganenko (1989) but is modified by the addition of an inner eastward ring current at a radial distance of ∼3 RE as suggested by observation. The other is a combination of the T89R model and the long version of the magnetic field model of Tsyganenko (1987) such that the former dominates the magnetic field in the inner magnetosphere, whereas the latter prevails in the distant tail. The distribution of plasma pressure, which is required to balance the magnetic force for each of these two field models, is computed along the tail axis in the midnight meridian. The occurrence of pressure anisotropy in the inner magnetospheric region is also taken into account by determining an empirical fit to the observed plasma pressure anisotropy. This effort is the first attempt to obtain the plasma pressure distribution in force equilibrium with magnetic stresses from an empirical field model with the inclusion of pressure anisotropy. The inclusion of pressure anisotropy alters the plasma pressure by as much as a factor of ∼3 in the inner magnetosphere. The deduced plasma pressure profile along the tail axis is found to be in good agreement with the observed quiet time plasma pressure for geocentric distances between ∼2 and ∼35 RE

A molecular arms race between host innate antiviral response and emerging human coronaviruses

Coronaviruses have been closely related with mankind for thousands of years. Communityacquired human coronaviruses have long been recognized to cause common cold. However, zoonotic coronaviruses are now becoming more a global concern with the discovery of highly pathogenic severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses causing severe respiratory diseases. Infections by these emerging human coronaviruses are characterized by less robust interferon production. Treatment of patients with recombinant interferon regimen promises beneficial outcomes, suggesting that compromised interferon expression might contribute at least partially to the severity of disease. The mechanisms by which coronaviruses evade host innate antiviral response are under intense investigations. This review focuses on the fierce arms race between host innate antiviral immunity and emerging human coronaviruses. Particularly, the host pathogen recognition receptors and the signal transduction pathways to mount an effective antiviral response against SARS and MERS coronavirus infection are discussed. On the other hand, the counter-measures evolved by SARS and MERS coronaviruses to circumvent host defense are also dissected. With a better understanding of the dynamic interaction between host and coronaviruses, it is hoped that insights on the pathogenesis of newly-identified highly pathogenic human coronaviruses and new strategies in antiviral development can be derived.postprin

Nanoarrays for the generation of complex optical wave-forms

Light beams with unusual forms of wavefront offer a host of useful features to extend the repertoire of those developing new optical techniques. Complex, non-uniform wavefront structures offer a wide range of optomechanical applications, from microparticle rotation, traction and sorting, through to contactless microfluidic motors. Beams combining transverse nodal structures with orbital angular momentum, or vector beams with novel polarization profiles, also present new opportunities for imaging and the optical transmission of information, including quantum entanglement effects. Whilst there are numerous well-proven methods for generating light with complex wave-forms, most current methods work on the basis of modifying a conventional Hermite-Gaussian beam, by passage through suitably tailored optical elements. It has generally been considered impossible to directly generate wave-front structured beams either by spontaneous or stimulated emission from individual atoms, ions or molecules. However, newly emerged principles have shown that emitter arrays, cast in an appropriately specified geometry, can overcome the obstacles: one possibility is a construct based on the electronic excitation of nanofabricated circular arrays. Recent experimental work has extended this concept to a phase-imprinted ring of apertures holographically encoded in a diffractive mask, generated by a programmed spatial light modulator. These latest advances are potentially paving the way for creating new sources of structured light

Post Brexit Britain and the Pay Culture: Challenges and Opportunities

This paper examines the impact of Brexit on the financial services regulation in relation to three areas linked to executive remuneration. They include: the bonus cap, the clawback of pay and the level of disclosure needed by shareholders regarding details of directors’ remuneration. It will be argued that legally, Brexit will have little impact on all three areas. UK legislation has already incorporated a great deal of EU legislation. Status quo of retaining such legal restrictions seems sensible in light of public sentiment towards unfairness in executive compensation and uncertainty towards the Brexit negotiations. Nevertheless, London faces stiff competition from other major international financial centres in a post-Brexit era. The loss of single passporting rights is also encouraging major banks to invest in other European financial centres. Brexit creates opportunities too. With the integration of digital technology, it is possible to create convenient platforms where investors can read reports on executive remuneration

The urban-rural divide in complementary and alternative medicine use: A longitudinal study of 10,638 women

Background: Research has identified women in rural and remote areas as higher users of complementary and alternative medicine (CAM) practitioners than their urban counterparts. However, we currently know little about what influences women's CAM consumption across the urban/rural divide. This paper analyses 10,638 women's CAM use across urban and rural Australia.Methods: Data for this research comes from Survey 5 of the Australian Longitudinal Study on Women's Health conducted in 2007. The participants were aged 56-61years. The health status and health service use of CAM users and non-users were compared using chi-square tests for categorical variables and t-tests for continuous variables.Results: Women who consulted a CAM practitioner varied significantly by place of residence: 28%, 32% and 30% for urban, rural and remote areas respectively (P < .005). CAM users tended to be more dissatisfied with conventional care than CAM non-users, but this was consistent across the 3 areas of residence. CAM users have higher percentages of most symptoms but the only rural/urban differences were for severe tiredness, night sweats, depression and anxiety. For diagnosed diseases, CAM users have higher percentages of most diagnoses but only hypertension and skin cancer were statistically significantly higher for rural and remote but not urban women (P < .005).Conclusions: In contrast to some recent claims, our analysis suggests the lack of access to and/or patient dissatisfaction with conventional health practitioners may not play a central role in explaining higher use of CAM by women in rural and remote areas when compared to women in urban areas. © 2011 Adams et al; licensee BioMed Central Ltd

MicroRNA: master controllers of intracellular signaling pathways

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Cross-listing and Corporate Malfeasance: Evidence from P-chip Firms

The rapid growth of the private sector in China in recent decades has created a large number of capital-hungry private sector firms. An increasing number of these firms choose to raise equity capital on international exchanges, which typically have stronger disclosure, corporate governance, and investor protection regulations. In light of international investors’ and regulators’ concerns about the corporate finance practice of China’s private sector firms, particularly regarding the integrity of their reported earnings, we investigate whether these firms aggressively manipulate their accounts by examining those listed in Hong Kong, commonly known as P-chips. We find systematic evidence that P-chips engage in more earnings management and other corporate misbehaviors than their counterparts in Hong Kong. We posit and provide evidence consistent with cross-jurisdictional enforcement difficulty as a possible explanation to P-chips’ questionable practice, and discuss its implications

Genomic and Transcriptomic Alterations Associated with STAT3 Activation in Head and Neck Cancer.

BackgroundHyperactivation of STAT3 via constitutive phosphorylation of tyrosine 705 (Y705) is common in most human cancers, including head and neck squamous carcinoma (HNSCC). STAT3 is rarely mutated in cancer and the (epi)genetic alterations that lead to STAT3 activation are incompletely understood. Here we used an unbiased approach to identify genomic and epigenomic changes associated with pSTAT3(Y705) expression using data generated by The Cancer Genome Atlas (TCGA).Methods and findingsMutation, mRNA expression, promoter methylation, and copy number alteration data were extracted from TCGA and examined in the context of pSTAT3(Y705) protein expression. mRNA expression levels of 1279 genes were found to be associated with pSTAT3(705) expression. Association of pSTAT3(Y705) expression with caspase-8 mRNA expression was validated by immunoblot analysis in HNSCC cells. Mutation, promoter hypermethylation, and copy number alteration of any gene were not significantly associated with increased pSTAT3(Y705) protein expression.ConclusionsThese cumulative results suggest that unbiased approaches may be useful in identifying the molecular underpinnings of oncogenic signaling, including STAT3 activation, in HNSCC. Larger datasets will likely be necessary to elucidate signaling consequences of infrequent alterations

Effect of next-nearest neighbor coupling on the optical spectra in bilayer graphene

We investigate the dependence of the optical conductivity of bilayer graphene (BLG) on the intra- and inter-layer interactions using the most complete model to date. We show that the next nearest-neighbor intralayer coupling introduces new features in the low-energy spectrum that are highly sensitive to sample doping, changing significantly the ``universal'' conductance. Further, its interplay with interlayer couplings leads to an anisotropy in conductance in the ultraviolet range. We propose that experimental measurement of the optical conductivity of intrinsic and doped BLG will provide a good benchmark for the relative importance of intra- and inter-layer couplings at different doping levels.Comment: 5 pages, 5 figure

Numerical studies of the fractional quantum Hall effect in systems with tunable interactions

The discovery of the fractional quantum Hall effect in GaAs-based semiconductor devices has lead to new advances in condensed matter physics, in particular the possibility for exotic, topological phases of matter that possess fractional, and even non-Abelian, statistics of quasiparticles. One of the main limitations of the experimental systems based on GaAs has been the lack of tunability of the effective interactions between two-dimensional electrons, which made it difficult to stabilize some of the more fragile states, or induce phase transitions in a controlled manner. Here we review the recent studies that have explored the effects of tunability of the interactions offered by alternative two-dimensional systems, characterized by non-trivial Berry phases and including graphene, bilayer graphene and topological insulators. The tunability in these systems is achieved via external fields that change the mass gap, or by screening via dielectric plate in the vicinity of the device. Our study points to a number of different ways to manipulate the effective interactions, and engineer phase transitions between quantum Hall liquids and compressible states in a controlled manner.Comment: 9 pages, 4 figures, updated references; review for the CCP2011 conference, to appear in "Journal of Physics: Conference Series