21 research outputs found
Distribution of shortest cycle lengths in random networks
We present analytical results for the distribution of shortest cycle lengths
(DSCL) in random networks. The approach is based on the relation between the
DSCL and the distribution of shortest path lengths (DSPL). We apply this
approach to configuration model networks, for which analytical results for the
DSPL were obtained before. We first calculate the fraction of nodes in the
network which reside on at least one cycle. Conditioning on being on a cycle,
we provide the DSCL over ensembles of configuration model networks with degree
distributions which follow a Poisson distribution (Erdos-R\'enyi network),
degenerate distribution (random regular graph) and a power-law distribution
(scale-free network). The mean and variance of the DSCL are calculated. The
analytical results are found to be in very good agreement with the results of
computer simulations.Comment: 44 pages, 11 figure
The Soreq Applied Research Accelerator Facility (SARAF) - Overview, Research Programs and Future Plans
The Soreq Applied Research Accelerator Facility (SARAF) is under construction
in the Soreq Nuclear Research Center at Yavne, Israel. When completed at the
beginning of the next decade, SARAF will be a user facility for basic and
applied nuclear physics, based on a 40 MeV, 5 mA CW proton/deuteron
superconducting linear accelerator. Phase I of SARAF (SARAF-I, 4 MeV, 2 mA CW
protons, 5 MeV 1 mA CW deuterons) is already in operation, generating
scientific results in several fields of interest. The main ongoing program at
SARAF-I is the production of 30 keV neutrons and measurement of Maxwellian
Averaged Cross Sections (MACS), important for the astrophysical s-process. The
world leading Maxwellian epithermal neutron yield at SARAF-I (
epithermal neutrons/sec), generated by a novel Liquid-Lithium Target (LiLiT),
enables improved precision of known MACSs, and new measurements of
low-abundance and radioactive isotopes. Research plans for SARAF-II span
several disciplines: Precision studies of beyond-Standard-Model effects by
trapping light exotic radioisotopes, such as He, Li and
Ne, in unprecedented amounts (including meaningful studies already
at SARAF-I); extended nuclear astrophysics research with higher energy
neutrons, including generation and studies of exotic neutron-rich isotopes
relevant to the rapid (r-) process; nuclear structure of exotic isotopes; high
energy neutron cross sections for basic nuclear physics and material science
research, including neutron induced radiation damage; neutron based imaging and
therapy; and novel radiopharmaceuticals development and production. In this
paper we present a technical overview of SARAF-I and II, including a
description of the accelerator and its irradiation targets; a survey of
existing research programs at SARAF-I; and the research potential at the
completed facility (SARAF-II).Comment: 32 pages, 31 figures, 10 tables, submitted as an invited review to
European Physics Journal
The Posterior Matching Feedback Scheme for Joint Source-Channel Coding with Bandwidth Expansion
Abstract When transmitting a Gaussian source over an AWGN channel with an input power constraint and a quadratic distortion measure, it is well known that optimal performance can be obtained using an analog joint source-channel scalar scheme which merely scales the input and output signals. In the case of bandwidth expansion, such a joint source-channel analog scheme attaining optimal performance is no longer simple. However, when feedback is available a simple and sequential analog linear procedure based on the Schalkwijk-Kailath scheme for communication, is optimal. Recently, we have introduced a fundamental feedback communication scheme, termed posterior matching, which generalizes the Schalkwijk-Kailath scheme to arbitrary memoryless channels and input distributions. In this paper, we show how the posterior matching scheme can be adapted to the joint source-channel coding setting with bandwidth expansion and a general distortion measure, when feedback is available. I Introduction Suppose a memoryless source is to be transmitted over a memoryless channel with some input constraint, and the quality of the source's reconstruction at the receiving terminal is measured via some given distortion measure. In this case, the separation principle Optimal performance can be obtained in many cases without the artificial separation into source coding and channel coding, using a much simpler joint-source channe
Cluster analysis of resting-state fMRI time series
Functional MRI (fMRI) has become one of the leading methods for brain mapping in neuroscience. Recent advances in fMRI analysis were used to define the default state of brain activity, functional connectivity and basal activity. Basal activity measured with fMRI raised tremendous interest among neuroscientists since synchronized brain activity pattern could be retrieved while the subject rests (resting state fMRI). During recent years, a few signal processing schemes have been suggested to analyze the resting state blood oxygenation level dependent (BOLD) signal from simple correlations to spectral decomposition. In most of these analysis schemes, the question asked was which brain areas “behave” in the time domain similarly to a pre-specified ROI.
In this work we applied short time frequency analysis and clustering to study the spatial signal characteristics of resting state fMRI time series. Such analysis revealed that clusters of similar BOLD fluctuations are found in the cortex but also in the white matter and sub-cortical gray matter regions (thalamus). We found high similarities between the BOLD clusters and the neuro-anatomical appearance of brain regions.
Additional analysis of the BOLD time series revealed a strong correlation between head movements and clustering quality. Experiments performed with T1-weighted time series also provided similar quality of clustering. These observations led us to the conclusion that non-functional contributions to the BOLD time series can also account for symmetric appearance of signal fluctuations. These contributions may include head motions, the underling microvasculature anatomy and cellular morphology
Bottlebrush Block Copolymer Assembly in Ultraconfined Films: Effect of Substrate Selectivity
L'Auto-vélo : automobilisme, cyclisme, athlétisme, yachting, aérostation, escrime, hippisme / dir. Henri Desgranges
01 février 19291929/02/01 (A30,N10275)
MOESM5 of Urine cell-free microRNA as biomarkers for transitional cell carcinoma
Additional file 5. Differentially expressed miRNA in urine of TCC patients vs. healthy controls by SAMseq and DESeq 2 analyses
MOESM4 of Urine cell-free microRNA as biomarkers for transitional cell carcinoma
Additional file 4. SAMseq analysis of sequencing cDNA librariesâtop differentially expressed miRNA clusters in TCC patients vs. control individual
MOESM1 of Urine cell-free microRNA as biomarkers for transitional cell carcinoma
Additional file 1. Demographic characteristics of study participants
Identification of a Functional Risk Variant for Pemphigus Vulgaris in the <i>ST18</i> Gene
<div><p>Pemphigus vulgaris (PV) is a life-threatening autoimmune mucocutaneous blistering disease caused by disruption of intercellular adhesion due to auto-antibodies directed against epithelial components. Treatment is limited to immunosuppressive agents, which are associated with serious adverse effects. The propensity to develop the disease is in part genetically determined. We therefore reasoned that the delineation of PV genetic basis may point to novel therapeutic strategies. Using a genome-wide association approach, we recently found that genetic variants in the vicinity of the S<i>T18</i> gene confer a significant risk for the disease. Here, using targeted deep sequencing, we identified a PV-associated variant residing within the <i>ST18</i> promoter region (p<0.0002; odds ratio = 2.03). This variant was found to drive increased gene transcription in a p53/p63-dependent manner, which may explain the fact that ST18 is up-regulated in the skin of PV patients. We then discovered that when overexpressed, ST18 stimulates PV serum-induced secretion of key inflammatory molecules and contributes to PV serum-induced disruption of keratinocyte cell-cell adhesion, two processes previously implicated in the pathogenesis of PV. Thus, the present findings indicate that ST18 may play a direct role in PV and consequently represents a potential target for the treatment of this disease.</p></div