6,708 research outputs found
Fitting State Space Models with EViews
This paper demonstrates how state space models can be fitted in EViews. We first briefly introduce EViews as an econometric software package. Next we fit a local level model to the Nile data. We then show how a multivariate âÂÂlatent riskâ model can be developed, making use of the EViews programming environment. We conclude by summarizing the possibilities and limitations of the software package when it comes to state space modeling.
Geometry of entanglement witnesses parameterized by SO(3) group
We characterize a set of positive maps in matrix algebra of 4x4 complex
matrices. Equivalently, we provide a subset of entanglement witnesses
parameterized by the rotation group SO(3). Interestingly, these maps/witnesses
define two intersecting convex cones in the 3-dimensional parameter space. The
existence of two cones is related to the topological structure of the
underlying orthogonal group. We perform detailed analysis of the corresponding
geometric structure.Comment: 10 page
Deterministic implementation of weak quantum cubic nonlinearity
We propose a deterministic implementation of weak cubic nonlinearity, which
is a basic building block of a full scale CV quantum computation. Our proposal
relies on preparation of a specific ancillary state and transferring its
nonlinear properties onto the desired target by means of deterministic Gaussian
operations and feed-forward. We show that, despite the imperfections arising
from the deterministic nature of the operation, the weak quantum nonlinearity
can be implemented and verified with the current level of technology.Comment: 4 pages, 2 figure
Heterogeneous Exchange of Amalgams. II. Hydrogen Ion Concentration Effect on the Zn-Amalgam -Zn++ (S04--) Solution Exchange
The effect of hydrogen ion concentration on the exchange
of a Zn-amalgam-Zn2+ (S04--) solution in bMh the presence and
absence of oxygen has been investigated. The technique of radioactive
indicators was used and it was found that in an atmosphere
of nitrogen, the exchange rate does not change in the pH 4-6
range. From pH 2-4 the exchange rate is inversely proportional
to the hydrogen ion activity. In the presence of oxygen from
pH 2-6, zinc from the amalgam dis solves completely. At a
partial oxygen pressure of 0.2 atm. at hydrogen ion concentrations
ranging from 1 X 10 -s - 2.6 X 10 -2 g. ion 1.- 1 the zinc dissolves
by two processes. The principal proceiss due to depolarization
takes place by the reaction 02 + 2H20 + 4e- ~ 40H- . At a
partial oxygen pressure of 1.0 atm ., zinc dissolves by only one
process owing to the depolarization of oxygen by the same
reaction
Spin injection and spin accumulation in permalloy-copper mesoscopic spin valves
We study the electrical injection and detection of spin currents in a lateral
spin valve device, using permalloy (Py) as ferromagnetic injecting and
detecting electrodes and copper (Cu) as non-magnetic metal. Our multi-terminal
geometry allows us to experimentally distinguish different magneto resistance
signals, being 1) the spin valve effect, 2) the anomalous magneto resistance
(AMR) effect and 3) Hall effects. We find that the AMR contribution of the Py
contacts can be much bigger than the amplitude of the spin valve effect, making
it impossible to observe the spin valve effect in a 'conventional' measurement
geometry. However, these 'contact' magneto resistance signals can be used to
monitor the magnetization reversal process, making it possible to determine the
magnetic switching fields of the Py contacts of the spin valve device. In a
'non local' spin valve measurement we are able to completely isolate the spin
valve signal and observe clear spin accumulation signals at T=4.2 K as well as
at room temperature. We obtain spin diffusion lengths in copper of 1 micrometer
and 350 nm at T=4.2 K and room temperature respectively.Comment: 8 pages (incl. figures), 7 figures, RevTex, conferenc
Identification of novel therapeutic targets in the PI3K/AKT/mTOR pathway in hepatocellular carcinoma using targeted next generation sequencing.
Understanding genetic aberrations in cancer leads to discovery of new targets for cancer therapies. The genomic landscape of hepatocellular carcinoma (HCC) has not been fully described. Therefore, patients with refractory advanced/metastatic HCC referred for experimental therapies, who had adequate tumor tissue available, had targeted next generation sequencing (NGS) of their tumor samples using the Illumina HiSeq 2000 platform (Foundation One, Foundation Medicine, MA) and their treatment outcomes were analyzed. In total, NGS was obtained for 14 patients (median number of prior therapies, 1) with advanced/metastatic HCC. Of these 14 patients, 10 (71%) were men, 4 (29%) women, 6 (43%) had hepatitis B or C-related HCC. NGS revealed at least 1 molecular abnormality in 12 patients (range 0-8, median 2). Detected molecular aberrations led to putative activation of the PI3K/AKT/mTOR pathway (n=3 [mTOR, PIK3CA, NF1]), Wnt pathway (n=6 [CTNNA1, CTNNB1]), MAPK pathway (n=2 [MAP2K1, NRAS]), and aberrant DNA repair mechanisms, cell cycle control and apoptosis (n=18 [ATM, ATR, BAP1, CCND1, CDKN2A, CDK4, FGF3, FGF4, FGF19, MCL1, MDM2, RB1, TP53]). Of the 3 patients with molecular aberrations putatively activating the PI3K/AKT/mTOR pathway, 2 received therapies including a mTOR inhibitor and all demonstrated therapeutic benefit ranging from a partial response to minor shrinkage per RECIST (-30%, -15%; respectively). In conclusion, genomic alterations are common in advanced HCC. Refractory patients with alterations putatively activating the PI3K/AKT/mTOR pathway demonstrated early signals of clinical activity when treated with therapies targeting mTOR
Visibility bound caused by a distinguishable noise particle
We investigate how distinguishability of a "noise" particle degrades
interference of the "signal" particle. The signal, represented by an equatorial
state of a photonic qubit, is mixed with noise, represented by another photonic
qubit, via linear coupling on the beam splitter. We report on the degradation
of the "signal" photon interference depending on the degree of
indistinguishability between "signal" and "noise" photon. When the photons are
principally completely distinguishable but technically indistinguishable the
visibility drops to the value 1/sqrt(2). As the photons become more
indistinguishable the maximal visibility increases and reaches the unit value
for completely indistinguishable photons. We have examined this effect
experimentally using setup with fiber optics two-photon Mach-Zehnder
interferometer.Comment: 5 pages, 3 figures, Accepted to Phys. Rev.
Correlator Analysis of Multiparticle Events
A procedure for the evaluation of correlators of any order in a reasonable
computer time is presented. Connection between correlators and fluctuations of
the event mean values of observables is discussed. Extension of the procedure
to event-by-event approach is suggested. The usefulness of the method is
demonstrated using the events simulated within various models of multipaticle
production.Comment: LaTeX, 15 pages including 4 table
Interactions between variation in candidate genes and environmental factors in the etiology of schizophrenia and bipolar disorder : a systematic review
Schizophrenia and bipolar disorder (BD) are complex and multidimensional disorders with high heritability rates. The contribution of genetic factors to the etiology of these disorders is increasingly being recognized as the action of multiple risk variants with small effect sizes, which might explain only a minor part of susceptibility. On the other site, numerous environmental factors have been found to play an important role in their causality. Therefore, in recent years, several studies focused on gene × environment interactions that are believed to bridge the gap between genetic underpinnings and environmental insults. In this article, we performed a systematic review of studies investigating gene × environment interactions in BD and schizophrenia spectrum phenotypes. In the majority of studies from this field, interacting effects of variation in genes encoding catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), and FK506-binding protein 5 (FKBP5) have been explored. Almost consistently, these studies revealed that polymorphisms in COMT, BDNF, and FKBP5 genes might interact with early life stress and cannabis abuse or dependence, influencing various outcomes of schizophrenia spectrum disorders and BD. Other interactions still require further replication in larger clinical and non-clinical samples. In addition, future studies should address the direction of causality and potential mechanisms of the relationship between gene × environment interactions and various categories of outcomes in schizophrenia and BD
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