65 research outputs found
Continuous quantum measurement of a Bose-Einstein condensate: a stochastic Gross-Pitaevskii equation
We analyze the dynamics of a Bose-Einstein condensate undergoing a continuous
dispersive imaging by using a Lindblad operator formalism. Continuous strong
measurements drive the condensate out of the coherent state description assumed
within the Gross-Pitaevskii mean-field approach. Continuous weak measurements
allow instead to replace, for timescales short enough, the exact problem with
its mean-field approximation through a stochastic analogue of the
Gross-Pitaevskii equation. The latter is used to show the unwinding of a dark
soliton undergoing a continuous imaging.Comment: 13 pages, 10 figure
Disease-specific, neurosphere-derived cells as models for brain disorders
There is a pressing need for patient-derived cell models of brain diseases that are relevant and robust enough to produce the large quantities of cells required for molecular and functional analyses. We describe here a new cell model based on patient-derived cells from the human olfactory mucosa, the organ of smell, which regenerates throughout life from neural stem cells. Olfactory mucosa biopsies were obtained from healthy controls and patients with either schizophrenia, a neurodevelopmental psychiatric disorder, or Parkinson's disease, a neurodegenerative disease. Biopsies were dissociated and grown as neurospheres in defined medium. Neurosphere-derived cell lines were grown in serum-containing medium as adherent monolayers and stored frozen. By comparing 42 patient and control cell lines we demonstrated significant disease-specific alterations in gene expression, protein expression and cell function, including dysregulated neurodevelopmental pathways in schizophrenia and dysregulated mitochondrial function, oxidative stress and xenobiotic metabolism in Parkinson's disease. The study has identified new candidate genes and cell pathways for future investigation. Fibroblasts from schizophrenia patients did not show these differences. Olfactory neurosphere-derived cells have many advantages over embryonic stem cells and induced pluripotent stem cells as models for brain diseases. They do not require genetic reprogramming and they can be obtained from adults with complex genetic diseases. They will be useful for understanding disease aetiology, for diagnostics and for drug discovery
Directed flow in Au+Au, Xe+CsI and Ni+Ni collisions and the nuclear equation of state
We present new experimental data on directed flow in collisions of Au+Au,
Xe+CsI and Ni+Ni at incident energies from 90 to 400A MeV. We study the
centrality and system dependence of integral and differential directed flow for
particles selected according to charge. All the features of the experimental
data are compared with Isospin Quantum Molecular Dynamics (IQMD) model
calculations in an attempt to extract information about the nuclear matter
equation of state (EoS). We show that the combination of rapidity and
transverse momentum analysis of directed flow allow to disentangle various
parametrizations in the model. At 400A MeV, a soft EoS with momentum dependent
interactions is best suited to explain the experimental data in Au+Au and
Xe+CsI, but in case of Ni+Ni the model underpredicts flow for any EoS. At 90A
MeV incident beam energy, none of the IQMD parametrizations studied here is
able to consistently explain the experimental data.Comment: RevTeX, 20 pages, 30 eps figures, accepted for publication in Phys.
Rev. C. Data files available at http://www.gsi.de/~fopiwww/pub
Identification of seven novel loci associated with amino acid levels using single-variant and gene-based tests in 8545 Finnish men from the METSIM study
Comprehensivemetabolite profiling capturesmany highly heritable traits, including amino acid levels, which are potentially sensitive biomarkers for disease pathogenesis. To better understand the contribution of genetic variation to amino acid levels, we performed single variant and gene-based tests of association between nine serumamino acids (alanine, glutamine, glycine, histidine, isoleucine, leucine, phenylalanine, tyrosine, and valine) and 16.6million genotyped and imputed variants in 8545 nondiabetic Finnishmen fromtheMETabolic Syndrome In Men (METSIM) study with replication in Northern Finland Birth Cohort (NFBC1966).We identified five novel loci associated with amino acid levels (P = < 5×10-8): LOC157273/PPP1R3B with glycine (rs9987289, P = 2.3×10-26); ZFHX3 (chr16:73326579,minor allele frequency (MAF) = 0.42%, P = 3.6×10-9), LIPC (rs10468017, P = 1.5×10-8), and WWOX (rs9937914, P = 3.8×10-8) with alanine; and TRIB1 with tyrosine (rs28601761, P = 8×10-9). Gene-based tests identified two novel genes harboringmissense variants ofMAF < 1% that show aggregate association with amino acid levels: PYCR1 with glycine (Pgene = 1.5×10-6) and BCAT2 with valine (Pgene = 7.4×10-7); neither gene was implicated by single variant association tests. These findings are among the first applications of gene-based tests to identify new loci for amino acid levels. In addition to the seven novel gene associations, we identified five independent signals at established amino acid loci, including two rare variant signals at GLDC (rs138640017,MAF=0.95%, Pconditional = 5.8×10-40) with glycine levels and HAL (rs141635447,MAF = 0.46%, Pconditional = 9.4×10-11) with histidine levels. Examination of all single variant association results in our data revealed a strong inverse relationship between effect size and MAF (Ptrend < 0.001). These novel signals provide further insight into the molecularmechanisms of amino acidmetabolismand potentially, their perturbations in disease
Associations of autozygosity with a broad range of human phenotypes
In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding
Your SRB: a cross platform interface for SRB and digital libraries
Many large scale research programs with massive data requirements (e.g. the Particle Physics Data Grid, the Biomedical Informatics Research Network) use SRB to manage research data collections. Despite this broad adoption, the potential of SRB and Data Grids is not fully utilized by the general research community. The reason for this under utilisation comes in part from the complexity of the Data Grid model and the lack of quality interfaces to SRB, making it difficult to use and configure.\ud
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YourSRB, is a system developed in the course of our research which provides an intuitive interface to SRB and aims to enable a broader community to benefit from SRB. The system also simplifies the use of SRB's awkward-to-initiate federation schemes, making SRB more suitable for use as the core of an organisational level research repository. In addition, our approach to federation makes the YourSRB system suitable for field workers who can off-line curate and annotate data, and subsequently federate their data with a primary store when network connectivity is available. YourSRB also implements data description and retrieval capabilities, enabling the effective management of massive data sets over multiple storage resources
A Modern Day Evaluation of Organ Preservation for Muscle Invasive Bladder Cancer at a High-Volume Cancer Center
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