3,036 research outputs found
Combination quetiapine therapy in the long-term treatment of patients with bipolar I disorder
OBJECTIVE: Determine the long-term effectiveness of quetiapine in combination with standard treatments in preventing relapses for patients with bipolar I disorders METHOD: Twenty-one outpatients with type I bipolar disorder who had inadequate responses to ongoing standard therapies were treated with add-on quetiapine in an open-label study. The quetiapine dose was increased until clinical response occurred. Illness response was assessed using the Clinical Global Impression (CGI) scale. Relapse rates before and during quetiapine treatment were compared by calculating incidence risk ratios. RESULTS: Quetiapine was added to ongoing standard therapy for 26 to 78 weeks. Thirteen patients received combination therapy for at least 52 weeks. The mean quetiapine dose received was 518 ± 244 mg/day. There were highly significant improvements in overall relapse rate, manic/mixed relapse rate, and depression relapse rate in the period during quetiapine treatment compared with the period before quetiapine was initiated. The calculated relative risk of relapse in the absence of quetiapine treatment was 2.9 overall (95% confidence interval, 1.5~5.6), 3.3 for manic/mixed relapse (95% confidence interval, 1.5~7.1), and 2.4 for depressive relapse (95% confidence interval, 1.3~4.4). The mean Clinical Global Impression scores improved significantly from baseline during 26 weeks of quetiapine treatment in 21 patients (p = 0.002) and remained significantly better during a 52-week treatment period in 13 patients (p = 0.036). CONCLUSION: Long-term treatment with quetiapine combination therapy reduced the probability of manic/mixed and depressive relapses and improved symptoms in patients with bipolar I disorder who had inadequate responses to ongoing standard treatment
The Role of SurA PPIase Domains in Preventing Aggregation of the Outer Membrane Proteins tOmpA and OmpT
SurA is a conserved ATP-independent periplasmic chaperone involved in the biogenesis of outer-membrane proteins (OMPs). Escherichia coli SurA has a core domain and two peptidylprolyl isomerase (PPIase) domains, the role(s) of which remain unresolved. Here we show that while SurA homologues in early proteobacteria typically contain one or no PPIase domains, the presence of two PPIase domains is common in SurA in later proteobacteria, implying an evolutionary advantage for this domain architecture. Bioinformatics analysis of > 350,000 OMP sequences showed that their length, hydrophobicity and aggregation propensity are similar across the proteobacterial classes, ruling out a simple correlation between SurA domain architecture and these properties of OMP sequences. To investigate the role of the PPIase domains in SurA activity, we deleted one or both PPIase domains from E. coli SurA and investigated the ability of the resulting proteins to bind and prevent the aggregation of tOmpA (19 kDa) and OmpT (33 kDa). The results show that wild-type SurA inhibits the aggregation of both OMPs, as do the cytoplasmic OMP chaperones trigger factor and SecB. However, while the ability of SurA to bind and prevent tOmpA aggregation does not depend on its PPIase domains, deletion of even a single PPIase domain ablates the ability of SurA to prevent OmpT aggregation. The results demonstrate that the core domain of SurA endows its generic chaperone ability, while the presence of PPIase domains enhances its chaperone activity for specific OMPs, suggesting one reason for the conservation of multiple PPIase domains in SurA in proteobacteria
Extended Lifetime in Computational Evolution of Isolated Black Holes
Solving the 4-d Einstein equations as evolution in time requires solving
equations of two types: the four elliptic initial data (constraint) equations,
followed by the six second order evolution equations. Analytically the
constraint equations remain solved under the action of the evolution, and one
approach is to simply monitor them ({\it unconstrained} evolution).
The problem of the 3-d computational simulation of even a single isolated
vacuum black hole has proven to be remarkably difficult. Recently, we have
become aware of two publications that describe very long term evolution, at
least for single isolated black holes. An essential feature in each of these
results is {\it constraint subtraction}. Additionally, each of these approaches
is based on what we call "modern," hyperbolic formulations of the Einstein
equations. It is generally assumed, based on computational experience, that the
use of such modern formulations is essential for long-term black hole
stability. We report here on comparable lifetime results based on the much
simpler ("traditional") - formulation.
We have also carried out a series of {\it constrained} 3-d evolutions of
single isolated black holes. We find that constraint solution can produce
substantially stabilized long-term single hole evolutions. However, we have
found that for large domains, neither constraint-subtracted nor constrained
- evolutions carried out in Cartesian coordinates admit
arbitrarily long-lived simulations. The failure appears to arise from features
at the inner excision boundary; the behavior does generally improve with
resolution.Comment: 20 pages, 6 figure
Broadband laser cooling of trapped atoms with ultrafast pulses
We demonstrate broadband laser cooling of atomic ions in an rf trap using
ultrafast pulses from a modelocked laser. The temperature of a single ion is
measured by observing the size of a time-averaged image of the ion in the known
harmonic trap potential. While the lowest observed temperature was only about 1
K, this method efficiently cools very hot atoms and can sufficiently localize
trapped atoms to produce near diffraction-limited atomic images
Holographic evolution of the mutual information
We compute the time evolution of the mutual information in out of equilibrium
quantum systems whose gravity duals are Vaidya spacetimes in three and four
dimensions, which describe the formation of a black hole through the collapse
of null dust. We find the holographic mutual information to be non monotonic in
time and always monogamous in the ranges explored. We also find that there is a
region in the configuration space where it vanishes at all times. We show that
the null energy condition is a necessary condition for both the strong
subadditivity of the holographic entanglement entropy and the monogamy of the
holographic mutual information.Comment: 32 pages, 16 figure
Adjusted ADM systems and their expected stability properties: constraint propagation analysis in Schwarzschild spacetime
In order to find a way to have a better formulation for numerical evolution
of the Einstein equations, we study the propagation equations of the
constraints based on the Arnowitt-Deser-Misner formulation. By adjusting
constraint terms in the evolution equations, we try to construct an
"asymptotically constrained system" which is expected to be robust against
violation of the constraints, and to enable a long-term stable and accurate
numerical simulation. We first provide useful expressions for analyzing
constraint propagation in a general spacetime, then apply it to Schwarzschild
spacetime. We search when and where the negative real or non-zero imaginary
eigenvalues of the homogenized constraint propagation matrix appear, and how
they depend on the choice of coordinate system and adjustments. Our analysis
includes the proposal of Detweiler (1987), which is still the best one
according to our conjecture but has a growing mode of error near the horizon.
Some examples are snapshots of a maximally sliced Schwarzschild black hole. The
predictions here may help the community to make further improvements.Comment: 23 pages, RevTeX4, many figures. Revised version. Added subtitle,
reduced figures, rephrased introduction, and a native checked. :-
Positivity, entanglement entropy, and minimal surfaces
The path integral representation for the Renyi entanglement entropies of
integer index n implies these information measures define operator correlation
functions in QFT. We analyze whether the limit , corresponding
to the entanglement entropy, can also be represented in terms of a path
integral with insertions on the region's boundary, at first order in .
This conjecture has been used in the literature in several occasions, and
specially in an attempt to prove the Ryu-Takayanagi holographic entanglement
entropy formula. We show it leads to conditional positivity of the entropy
correlation matrices, which is equivalent to an infinite series of polynomial
inequalities for the entropies in QFT or the areas of minimal surfaces
representing the entanglement entropy in the AdS-CFT context. We check these
inequalities in several examples. No counterexample is found in the few known
exact results for the entanglement entropy in QFT. The inequalities are also
remarkable satisfied for several classes of minimal surfaces but we find
counterexamples corresponding to more complicated geometries. We develop some
analytic tools to test the inequalities, and as a byproduct, we show that
positivity for the correlation functions is a local property when supplemented
with analyticity. We also review general aspects of positivity for large N
theories and Wilson loops in AdS-CFT.Comment: 36 pages, 10 figures. Changes in presentation and discussion of
Wilson loops. Conclusions regarding entanglement entropy unchange
Renormalization Group Functions for Two-Dimensional Phase Transitions: To the Problem of Singular Contributions
According to the available publications, the field theoretical
renormalization group (RG) approach in the two-dimensional case gives the
critical exponents that differ from the known exact values. This fact was
attempted to explain by the existence of nonanalytic contributions in the RG
functions. The situation is analysed in this work using a new algorithm for
summing divergent series that makes it possible to analyse dependence of the
results for the critical exponents on the expansion coefficients for RG
functions. It has been shown that the exact values of all the exponents can be
obtained with a reasonable form of the coefficient functions. These functions
have small nonmonotonities or inflections, which are poorly reproduced in
natural interpolations. It is not necessary to assume the existence of singular
contributions in RG functions.Comment: PDF, 11 page
Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
We present a new measurement of the kinematic Sunyaev-Zeldovich effect using
data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation
Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area,
we evaluate the mean pairwise baryon momentum associated with the positions of
50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A
non-zero signal arises from the large-scale motions of halos containing the
sample galaxies. The data fits an analytical signal model well, with the
optical depth to microwave photon scattering as a free parameter determining
the overall signal amplitude. We estimate the covariance matrix of the mean
pairwise momentum as a function of galaxy separation, using microwave sky
simulations, jackknife evaluation, and bootstrap estimates. The most
conservative simulation-based errors give signal-to-noise estimates between 3.6
and 4.1 for varying galaxy luminosity cuts. We discuss how the other error
determinations can lead to higher signal-to-noise values, and consider the
impact of several possible systematic errors. Estimates of the optical depth
from the average thermal Sunyaev-Zeldovich signal at the sample galaxy
positions are broadly consistent with those obtained from the mean pairwise
momentum signal.Comment: 15 pages, 8 figures, 2 table
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