2,093 research outputs found
Bohm's interpretation and maximally entangled states
Several no-go theorems showed the incompatibility between the locality
assumption and quantum correlations obtained from maximally entangled spin
states. We analyze these no-go theorems in the framework of Bohm's
interpretation. The mechanism by which non-local correlations appear during the
results of measurements performed on distant parts of entangled systems is
explicitly put into evidence in terms of Bohmian trajectories. It is shown that
a GHZ like contradiction of the type+1=-1 occurs for well-chosen initial
positions of the Bohmian trajectories and that it is this essential
non-classical feature that makes it possible to violate the locality condition.Comment: 18 page
Calculation of the effect of random superfluid density on the temperature dependence of the penetration depth
Microscopic variations in composition or structure can lead to nanoscale
inhomogeneity in superconducting properties such as the magnetic penetration
depth, but measurements of these properties are usually made on longer length
scales. We solve a generalized London equation with a non-uniform penetration
depth, lambda(r), obtaining an approximate solution for the disorder-averaged
Meissner effect. We find that the effective penetration depth is different from
the average penetration depth and is sensitive to the details of the disorder.
These results indicate the need for caution when interpreting measurements of
the penetration depth and its temperature dependence in systems which may be
inhomogeneous
Early evaluation of patient risk for substantial weight gain during olanzapine treatment for schizophrenia, schizophreniform, or schizoaffective disorder
BACKGROUND: To make well informed treatment decisions for their patients, clinicians need credible information about potential risk for substantial weight gain. We therefore conducted a post-hoc analysis of clinical trial data, examining early weight gain as a predictor of later substantial weight gain. METHODS: Data from 669 (Study 1) and 102 (Study 2) olanzapine-treated patients diagnosed with schizophrenia, schizophreniform, or schizoaffective disorder were analyzed to identify and validate weight gain cut-offs at Weeks 1–4 that were predictive of substantial weight gain (defined as an increase of ≥ 5, 7, 10 kg or 7% of baseline weight) after approximately 30 weeks of treatment. Baseline characteristics alone, baseline characteristics plus weight change from baseline to Weeks 1, 2, 3 or 4, and weight change from baseline to Weeks 1, 2, 3, or 4 alone were evaluated as predictors of substantial weight gain. Similar analyses were performed to determine BMI increase cut-offs at Weeks 1–4 of treatment that were predictive of substantial increase in BMI (1, 2 or 3 kg/m(2 )increase from baseline). RESULTS: At Weeks 1 and 2, predictions based on early weight gain plus baseline characteristics were more robust than those based on early weight gain alone. However, by Weeks 3 and 4, there was little difference between the operating characteristics associated with these two sets of predictors. The positive predictive values ranged from 30.1% to 73.5%, while the negative predictive values ranged from 58.1% to 89.0%. Predictions based on early BMI increase plus baseline characteristics were not uniformly more robust at any time compared to those based on early BMI increase alone. The positive predictive values ranged from 38.3% to 83.5%, while negative predictive values ranged from 42.1% to 84.7%. For analyses of both early weight gain and early BMI increase, results for the validation dataset were similar to those observed in the primary dataset. CONCLUSION: Results from these analyses can be used by clinicians to evaluate risk of substantial weight gain or BMI increase for individual patients. For instance, negative predictive values based on data from these studies suggest approximately 88% of patients who gain less than 2 kg by Week 3 will gain less than 10 kg after 26–34 weeks of olanzapine treatment. Analysis of changes in BMI suggests that approximately 84% of patients who gain less than .64 kg/m(2 )in BMI by Week 3 will gain less than 3 kg/m(2 )in BMI after 26–34 weeks of olanzapine treatment. Further research in larger patient populations for longer periods is necessary to confirm these results
Multiband Superconductivity in KFe2As2: Evidence for one Isotropic and several Liliputian Energy Gaps
We report a detailed low-temperature thermodynamic investigation (heat
capacity and magnetization) of the superconducting state of KFe2As2 for H || c
axis. Our measurements reveal that the properties of KFe2As2 are dominated by a
relatively large nodeless energy gap (Delta?0 = 1.9 kBTc) which excludes dx2-y2
symmetry. We prove the existence of several additional extremely small gaps
(?Delta0 < 1.0 kBTc) that have a profound impact on the low-temperature and
low-field behavior, similar to MgB2, CeCoIn5 and PrOs4Sb12. The zero-field heat
capacity is analyzed in a realistic self-consistent 4-band BCS model which
qualitatively reproduces the recent laser ARPES results of Okazaki et al.
(Science 337 (2012) 1314). Our results show that extremely low-temperature
measurements, i.e. T < 0.1 K, will be required in order to resolve the question
of the existence of line nodes in this compound.Comment: 7 pages, 6 figure
The Gravity Dual of the Ising Model
We evaluate the partition function of three dimensional theories of gravity
in the quantum regime, where the AdS radius is Planck scale and the central
charge is of order one. The contribution from the AdS vacuum sector can - with
certain assumptions - be computed and equals the vacuum character of a minimal
model CFT. The torus partition function is given by a sum over geometries which
is finite and computable. For generic values of Newton's constant G and the AdS
radius L the result has no Hilbert space interpretation, but in certain cases
it agrees with the partition function of a known CFT. For example, the
partition function of pure Einstein gravity with G=3L equals that of the Ising
model, providing evidence that these theories are dual. We also present
somewhat weaker evidence that the 3-state and tricritical Potts models are dual
to pure higher spin theories of gravity based on SL(3) and E_6, respectively.Comment: 42 page
Beta-decay branching ratios of 62Ga
Beta-decay branching ratios of 62Ga have been measured at the IGISOL facility
of the Accelerator Laboratory of the University of Jyvaskyla. 62Ga is one of
the heavier Tz = 0, 0+ -> 0+ beta-emitting nuclides used to determine the
vector coupling constant of the weak interaction and the Vud quark-mixing
matrix element. For part of the experimental studies presented here, the
JYFLTRAP facility has been employed to prepare isotopically pure beams of 62Ga.
The branching ratio obtained, BR= 99.893(24)%, for the super-allowed branch is
in agreement with previous measurements and allows to determine the ft value
and the universal Ft value for the super-allowed beta decay of 62Ga
Hydrothermal alteration mapping of Siberian gold-ore fields based on satellite spectroscopy data
The mapping of the hydrothermal alterations in Urjahskoe and Fedorov-Kedrov gold-ore fields was conducted by applying channel relationship method (band ratio) based on ASTER spectral-zonal satellite image data. It was determined that the calculated mineral indices in ore-bearing structures are zonal. Outer ore-bearing structures revealed increased ferric mineral index values, while inner - high epidote- chlorite- calcite and muscovite- siderite mineral index values. Detected regularities could be used in identifying potential gold-ore bearing areas within identical fields based on remote sensing survey data
A Mathematical Framework for Agent Based Models of Complex Biological Networks
Agent-based modeling and simulation is a useful method to study biological
phenomena in a wide range of fields, from molecular biology to ecology. Since
there is currently no agreed-upon standard way to specify such models it is not
always easy to use published models. Also, since model descriptions are not
usually given in mathematical terms, it is difficult to bring mathematical
analysis tools to bear, so that models are typically studied through
simulation. In order to address this issue, Grimm et al. proposed a protocol
for model specification, the so-called ODD protocol, which provides a standard
way to describe models. This paper proposes an addition to the ODD protocol
which allows the description of an agent-based model as a dynamical system,
which provides access to computational and theoretical tools for its analysis.
The mathematical framework is that of algebraic models, that is, time-discrete
dynamical systems with algebraic structure. It is shown by way of several
examples how this mathematical specification can help with model analysis.Comment: To appear in Bulletin of Mathematical Biolog
Clinical, biochemical, and genetic spectrum of seven patients with NFU1 deficiency
Disorders of the mitochondrial energy metabolism are clinically and genetically heterogeneous. An increasingly recognized subgroup is caused by defective mitochondrial iron-sulfur (Fe-S) cluster biosynthesis, with defects in 13 genes being linked to human disease to date. Mutations in three of them, NFU1, BOLA3, and IBA57, affect the assembly of mitochondrial [4Fe-4S] proteins leading to an impairment of diverse mitochondrial metabolic pathways and ATP production. Patients with defects in these three genes present with lactic acidosis, hyperglycinemia, and reduced activities of respiratory chain complexes I and II, the four lipoic acid-dependent 2-oxoacid dehydrogenases and the glycine cleavage system (GCS). To date, five different NFU1 pathogenic variants have been reported in 15 patients from 12 families. We report on seven new patients from five families carrying compound heterozygous or homozygous pathogenic NFU1 mutations identified by candidate gene screening and exome sequencing. Six out of eight different disease alleles were novel and functional studies were performed to support the pathogenicity of five of them. Characteristic clinical features included fatal infantile encephalopathy and pulmonary hypertension leading to death within the first 6 months of life in six out of seven patients. Laboratory investigations revealed combined defects of pyruvate dehydrogenase complex (five out of five) and respiratory chain complexes I and II+III (four out of five) in skeletal muscle and/or cultured skin fibroblasts as well as increased lactate (five out of six) and glycine concentration (seven out of seven). Our study contributes to a better definition of the phenotypic spectrum associated with NFU1 mutations and to the diagnostic workup of future patients
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