201 research outputs found
Virtual Currencies Like Bitcoin As A Paradigm Shift In The Field Of Transactions
Virtual currencies have been well-cited and well-discussed in the near past. Due to the loss of trust in the banking sector and the fear of loss of capital, low interest rates and uncertainty of existing currencies, the ground for a virtual currency was given. Virtual currencies and the money flows are controlled only online by the anonymous group of volunteers (also called peer); every single transaction is documented. Approximately 10,000 businesses worldwide accept payments with virtual currencies already, and the number is increasing steadily. This article analyzes the advantages and disadvantages of virtual currencies in comparison to real money and gives an outlook to a new banking system with high transparency and the chance to lead to a paradigm shift in the world of transactions and banking
Expression and function of conserved nuclear receptor genes in Caenorhabditis elegans
AbstractThe Caenorhabditis elegans genome encodes 284 nuclear receptor (NR) genes. Among these 284 NR genes are 15 genes conserved among the Metazoa. Here, we analyze the expression and function of eight heretofore uncharacterized conserved C. elegans NR genes. Reporter gene analysis demonstrates that these genes have distinct expression patterns and that a majority of the C. elegans cell types express a conserved NR gene. RNA interference with NR gene function resulted in visible phenotypes for three of the genes, revealing functions in various processes during postembryonic development. Five of the conserved NR genes are orthologs of NR genes that function during molting and metamorphosis in insects. Functional studies confirm a role for most of these ‘ecdysone cascade’ NR orthologs during the continuous growth and dauer molts. Transcript levels for these genes fluctuate in a reiterated pattern during the molting cycles, reminiscent of the expression hierarchy observed in the insect ecdysone response. Together, these analyses provide a foundation for further dissecting the role of NRs in nematode development as well as for evaluating conservation of NR functions among the Metazoa
The Science Case for the Planet Formation Imager (PFI)
Among the most fascinating and hotly-debated areas in contemporary
astrophysics are the means by which planetary systems are assembled from the
large rotating disks of gas and dust which attend a stellar birth. Although
important work has already been, and is still being done both in theory and
observation, a full understanding of the physics of planet formation can only
be achieved by opening observational windows able to directly witness the
process in action. The key requirement is then to probe planet-forming systems
at the natural spatial scales over which material is being assembled. By
definition, this is the so-called Hill Sphere which delineates the region of
influence of a gravitating body within its surrounding environment. The Planet
Formation Imager project (PFI) has crystallized around this challenging goal:
to deliver resolved images of Hill-Sphere-sized structures within candidate
planet-hosting disks in the nearest star-forming regions. In this contribution
we outline the primary science case of PFI. For this purpose, we briefly review
our knowledge about the planet-formation process and discuss recent
observational results that have been obtained on the class of transition disks.
Spectro-photometric and multi-wavelength interferometric studies of these
systems revealed the presence of extended gaps and complex density
inhomogeneities that might be triggered by orbiting planets. We present
detailed 3-D radiation-hydrodynamic simulations of disks with single and
multiple embedded planets, from which we compute synthetic images at
near-infrared, mid-infrared, far-infrared, and sub-millimeter wavelengths,
enabling a direct comparison of the signatures that are detectable with PFI and
complementary facilities such as ALMA. From these simulations, we derive some
preliminary specifications that will guide the array design and technology
roadmap of the facility.Comment: SPIE Astronomical Telescopes and Instrumentation conference, June
2014, Paper ID 9146-120, 13 pages, 3 Figure
Measuring portfolio performance using a modified measure of risk
This paper reports the results of an investigation into the properties of a theoretical modification of beta proposed by Leland (1999) and based on earlier work of Rubinstein (1976). It is shown that when returns are elliptically symmetric, beta is the appropriate measure of risk and that there are other situations in which the modified beta will be similar to the traditional measure based on the capital asset pricing model. For the case where returns have a normal distribution, it is shown that the criterion either does not exist or reduces exactly to the conventional beta. It is therefore conjectured that the modified measure will only be useful for portfolios that have nonstandard return distributions which incorporate skewness. For such situations, it is shown how to estimate the measure using regression and how to compare the resulting statistic with a traditional estimated beta using Hotelling's test. An empirical study based on stocks from the FTSE350 does not find evidence to support the use of the new measure even in the presence of skewness.Journal of Asset Management (2007) 7, 388-403. doi:10.1057/palgrave.jam.225005
Sparse Aperture Masking (SAM) at NAOS/CONICA on the VLT
The new operational mode of aperture masking interferometry has been added to
the CONICA camera which lies downstream of the Adaptive Optics (AO) corrected
focus provided by NAOS on the VLT-UT4 telescope. Masking has been shown to
deliver superior PSF calibration, rejection of atmospheric noise and robust
recovery of phase information through the use of closure phases. Over the
resolution range from about half to several resolution elements, masking
interferometry is presently unsurpassed in delivering high fidelity imaging and
direct detection of faint companions. Here we present results from
commissioning data using this powerful new operational mode, and discuss the
utility for masking in a variety of scientific contexts. Of particular interest
is the combination of the CONICA polarimetry capabilities together with SAM
mode operation, which has revealed structures never seen before in the
immediate circumstellar environments of dusty evolved stars.Comment: 11 pages, 10 figures, SPIE 201
Oscarkempffite, Ag10Pb4(Sb17Bi9)∑ 26S48, a new Sb-Bi member of the lillianite homologous series
Published by the Mineralogical Society. This is a 'preproof' accepted article for Mineralogical Magazine. This version may be subject to change during the production process.10.1180/minmag.2016.080.024. You are advised to consult the publisher's version if you wish to cite from it
Quantum realization of arbitrary joint measurability structures
In many a traditional physics textbook, a quantum measurement is defined as a
projective measurement represented by a Hermitian operator. In quantum
information theory, however, the concept of a measurement is dealt with in
complete generality and we are therefore forced to confront the more general
notion of positive-operator valued measures (POVMs) which suffice to describe
all measurements that can be implemented in quantum experiments. We study the
(in)compatibility of such POVMs and show that quantum theory realizes all
possible (in)compatibility relations among sets of POVMs. This is in contrast
to the restricted case of projective measurements for which commutativity is
essentially equivalent to compatibility. Our result therefore points out a
fundamental feature with respect to the (in)compatibility of quantum
observables that has no analog in the case of projective measurements.Comment: 6 pages, 3 figures; minor additions to the text; this is close to the
published version; title changed on publication when someone at Phys. Rev. A.
insisted: "we strongly prefer to avoid titles in the form of full sentences
(containing both a subject and a verb) because titles should indicate what is
being studied, rather than consist of a narrowly focused statement.
Protecting biodiversity in British Columbia: Recommendations for developing species at risk legislation
British Columbia has the greatest biological diversity of any province or territory in Canada. Yet increasing numbers of species in British Columbia are threatened with extinction. The current patchwork of provincial laws and regulations has not effectively prevented species declines. Recently, the Provincial Government has committed to enacting an endangered species law. Drawing upon our scientific and legal expertise, we offer recommendations for key features of endangered species legislation that build upon strengths and avoid weaknesses observed elsewhere. We recommend striking an independent Oversight Committee to provide recommendations about listing species, organize Recovery Teams, and monitor the efficacy of actions taken. Recovery Teams would evaluate and prioritize potential actions for individual species or groups of species that face common threats or live in a common area, based on best available evidence (including natural and social science and Indigenous Knowledge). Our recommendations focus on implementing an adaptive approach, with ongoing and transparent monitoring and reporting, to reduce delays between determining when a species is at risk and taking effective actions to save it. We urge lawmakers to include this strong evidentiary basis for species recovery as they tackle the scientific and socioeconomic challenges of building an effective species at risk Act
Protecting biodiversity in British Columbia: Recommendations for developing species at risk legislation
British Columbia has the greatest biological diversity of any province or territory in Canada. Yet increasing numbers of species in British Columbia are threatened with extinction. The current patchwork of provincial laws and regulations has not effectively prevented species declines. Recently, the Provincial Government has committed to enacting an endangered species law. Drawing upon our scientific and legal expertise, we offer recommendations for key features of endangered species legislation that build upon strengths and avoid weaknesses observed elsewhere. We recommend striking an independent Oversight Committee to provide recommendations about listing species, organize Recovery Teams, and monitor the efficacy of actions taken. Recovery Teams would evaluate and prioritize potential actions for individual species or groups of species that face common threats or live in a common area, based on best available evidence (including natural and social science and Indigenous Knowledge). Our recommendations focus on implementing an adaptive approach, with ongoing and transparent monitoring and reporting, to reduce delays between determining when a species is at risk and taking effective actions to save it. We urge lawmakers to include this strong evidentiary basis for species recovery as they tackle the scientific and socioeconomic challenges of building an effective species at risk Act
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