Exact Self-consistent Particle-like Solutions to the Equations of Nonlinear Scalar Electrodynamics in General Relativity

Exact self-consistent particle-like solutions with spherical and/or cylindrical symmetry to the equations governing the interacting system of scalar, electromagnetic and gravitational fields have been obtained. As a particular case it is shown that the equations of motion admit a special kind of solutions with sharp boundary known as droplets. For these solutions, the physical fields vanish and the space-time is flat outside of the critical sphere or cylinder. Therefore, the mass and the electric charge of these configurations are zero.Comment: 17 pages, Submitted to the International Journal of Theoretical Physic

Slow-light enhanced light-matter interactions with applications to gas sensing

Optical gas detection in microsystems is limited by the short micron scale optical path length available. Recently, the concept of slow-light enhanced absorption has been proposed as a route to compensate for the short path length in miniaturized absorption cells. We extend the previous perturbation theory to the case of a Bragg stack infiltrated by a spectrally strongly dispersive gas with a narrow and distinct absorption peak. We show that considerable signal enhancement is possible. As an example, we consider a Bragg stack consisting of PMMA infiltrated by O2. Here, the required optical path length for visible to near-infrared detection (~760 nm) can be reduced by at least a factor of 10^2, making a path length of 1 mm feasible. By using this technique, optical gas detection can potentially be made possible in microsystems

Sectors and Strategies of Global Communications Regulation

As the global communication network matures, the systems and procedures for regulating the growing network and its use are being challenged. The general proliferation of services or the specific demand for electronic transactions require guidance and control which the market alone cannot supply. Meanwhile, traditional regulatory regimes remain far from global or coherent. This article distinguishes between coordination and regulation to clarify areas where government intervention is unnecessary and where indispensable. It explores the current patchwork of regulatory approaches, reviews different regulatory areas and strategies, identifies trends, and highlights problem areas particular to electronic commerce and third party protection

CP-Violation in Bosonic Sector of SM with two Higgs Doublets

We investigate CP-violation effects in the bosonic sector of the Standard Model (SM) with two Higgs doublets. First we calculate the mass eigenstates of the physical neutral Higgses for small but nonzero CP-violation parameter $\xi_{\ast}$, and then a ``forward-backward'' asymmetry ${\cal A}_{fb}$ for the decay $H \to W^+W^-Z$ that would be a signal of CP-violation. Although the effects are in general small (${\cal A}_{fb} = \Gamma_{fb}/\Gamma \sim {\cal O}(10^{-3})$), ${\cal A}_{fb}$ turns out to be a rather clean signal of CP-violation, since neither the CP-conserving final state interactions nor the direct production background events contribute to $\Gamma_{fb}$. The process is a counterexample to the widespread belief that CP-violation processes must involve fermions. The CKM-type CP-violation effects that could in principle also contribute to ${\cal A}_{fb}$ are negligible. The nonzero ${\cal A}_{fb}$ could possibly be detected at some later stage in future colliders such as LHC or SSC.Comment: 11 pages (standard LaTeX), 3 figures (available from the author), DO-TH 93-1

Postglacial expansion of the arctic keystone copepod calanus glacialis

Calanus glacialis, a major contributor to zooplankton biomass in the Arctic shelf seas, is a key link between primary production and higher trophic levels that may be sensitive to climate warming. The aim of this study was to explore genetic variation in contemporary populations of this species to infer possible changes during the Quaternary period, and to assess its population structure in both space and time. Calanus glacialis was sampled in the fjords of Spitsbergen (Hornsund and Kongsfjorden) in 2003, 2004, 2006, 2009 and 2012. The sequence of a mitochondrial marker, belonging to the ND5 gene, selected for the study was 1249 base pairs long and distinguished 75 unique haplotypes among 140 individuals that formed three main clades. There was no detectable pattern in the distribution of haplotypes by geographic distance or over time. Interestingly, a Bayesian skyline plot suggested that a 1000-fold increase in population size occurred approximately 10,000 years before present, suggesting a species expansion after the Last Glacial Maximum.GAME from the National Science Centre, the Polish Ministry of Science and Higher Education Iuventus Plus [IP2014 050573]; FCT-PT [CCMAR/Multi/04326/2013]; [2011/03/B/NZ8/02876

Age- and Gender-Specific Normative Data of Grip and Pinch Strength in a Healthy Adult Swiss Population

Assessment of hand strength is used in a wide range of clinical settings especially during treatment of diseases affecting the function of the hand. This investigation aimed to determine age- and gender-specific reference values for grip and pinch strength in a normal Swiss population with special regard to old and very old subjects as well as to different levels of occupational demand. Hand strength data were collected using a Jamar dynamometer and a pinch gauge with standard testing position, protocol and instructions. Analysis of the data from 1023 tested subjects between 18 and 96 years revealed a curvilinear relationship of grip and pinch strength to age, a correlation to height, weight and significant differences between occupational groups. Hand strength values differed significantly from those of other populations, confirming the thesis that applying normative data internationally is questionable. Age- and gender-specific reference values for grip and pinch strength are presented

The morphological transformation of ram pressure stripped galaxies: a pathway from late to early galaxy types

We investigate how the ageing of stellar populations can drive a morphological transformation in galaxies whose star formation (SF) activity has been quenched on short timescales, like in cluster galaxies subject to ram pressure stripping from the intracluster medium. For this purpose, we use a sample of 91 galaxies with MUSE data from the GASP program and of their spatially resolved SF history derived with the spectral modelling software SINOPSIS. We simulate the future continuation of the SF activities by exploring two quenching scenarios: an instantaneous truncation of the SF across the whole disc, and an outside-in quenching with typical stripping timescales of 0.5 Gyr and 1 Gyr. For each scenario we produce mock MUSE spectroscopic datacubes and optical images for our galaxies during their evolution, and classify their morphology using a new diagnostic tool, calibrated on cluster galaxies from the OmegaWINGS Survey. We find that, in all scenarios considered, the initial galaxy population dominated by blue-cloud spirals (90%) evolves into a mixed population mostly composed by red-sequence spirals (50-55%) and lenticulars (~40%). The morphology transformation is completed after just 1.5-3.5 Gyr, proceeding faster in more efficient quenching scenarios. Our results indicate that, even without accounting for dynamical processes, SF quenching caused by the harsh environment of a cluster can significantly affect the morphology of the infalling galaxy population on timescales of a few Gyr.Comment: 19 pages, 11 figures, accepted for publication in MNRA

A New Species of River Dolphin from Brazil or:How Little Do We Know Our Biodiversity

True river dolphins are some of the rarest and most endangered of all vertebrates. They comprise relict evolutionary lineages of high taxonomic distinctness and conservation value, but are afforded little protection. We report the discovery of a new species of a river dolphin from the Araguaia River basin of Brazil, the first such discovery in nearly 100 years. The species is diagnosable by a series of molecular and morphological characters and diverged from its Amazonian sister taxon 2.08 million years ago. The estimated time of divergence corresponds to the separation of the Araguaia-Tocantins basin from the Amazon basin. This discovery highlights the immensity of the deficit in our knowledge of Neotropical biodiversity, as well as vulnerability of biodiversity to anthropogenic actions in an increasingly threatened landscape. We anticipate that this study will provide an impetus for the taxonomic and conservation reanalysis of other taxa shared between the Araguaia and Amazon aquatic ecosystems, as well as stimulate historical biogeographical analyses of the two basins