The path-integral analysis of an associative memory model storing an infinite number of finite limit cycles

It is shown that an exact solution of the transient dynamics of an associative memory model storing an infinite number of limit cycles with l finite steps by means of the path-integral analysis. Assuming the Maxwell construction ansatz, we have succeeded in deriving the stationary state equations of the order parameters from the macroscopic recursive equations with respect to the finite-step sequence processing model which has retarded self-interactions. We have also derived the stationary state equations by means of the signal-to-noise analysis (SCSNA). The signal-to-noise analysis must assume that crosstalk noise of an input to spins obeys a Gaussian distribution. On the other hand, the path-integral method does not require such a Gaussian approximation of crosstalk noise. We have found that both the signal-to-noise analysis and the path-integral analysis give the completely same result with respect to the stationary state in the case where the dynamics is deterministic, when we assume the Maxwell construction ansatz. We have shown the dependence of storage capacity (alpha_c) on the number of patterns per one limit cycle (l). Storage capacity monotonously increases with the number of steps, and converges to alpha_c=0.269 at l ~= 10. The original properties of the finite-step sequence processing model appear as long as the number of steps of the limit cycle has order l=O(1).Comment: 24 pages, 3 figure

Linear Complexity Lossy Compressor for Binary Redundant Memoryless Sources

A lossy compression algorithm for binary redundant memoryless sources is presented. The proposed scheme is based on sparse graph codes. By introducing a nonlinear function, redundant memoryless sequences can be compressed. We propose a linear complexity compressor based on the extended belief propagation, into which an inertia term is heuristically introduced, and show that it has near-optimal performance for moderate block lengths.Comment: 4 pages, 1 figur

Cost-Effectiveness Analysis of Transanal Irrigation for Managing Neurogenic Bowel Dysfunction in Japan.

BACKGROUND: Neurogenic bowel dysfunction (NBD) is a common sequela in Spinal Cord Injury (SCI) patients. Bowel dysfunction symptoms have a significant negative impact on quality of life (QOL) and are often socially disabling. Transanal irrigation (TAI) is a bowel management procedure that significantly mitigates NBD symptoms in patients refractory to standard bowel care (SBC) by reducing the incidence of fecal incontinence, ameliorating constipation, and improving QOL. TAI devices are used across many countries such as the United Kingdom, Germany, and France, and introduction of the devices is being considered in Japan. In this context, a cost-effectiveness analysis specific to Japanese settings is relevant. OBJECTIVES: To analyze the cost-effectiveness of TAI for bowel management of SCI patients with NBD in a Japanese clinical setting. Methods: A modified version of a previously developed and published Markov model was used to evaluate the cost-effectiveness of TAI. In the model, SCI patients using TAI due to NBD were compared with SCI patients not responding to TAI and continuing with SBC. Quality-adjusted Life Years (QALYs) were used as the primary effectiveness measure, and the analysis was conducted from the payer's perspective. RESULTS: The model predicts a lifetime incremental cost of TAI to be 3 198 687 yen compared with SBC. TAI provided an additional 0.8 QALY, which leads to an incremental cost-effectiveness ratio (ICER) of TAI vs SBC of 4 016 287 yen/QALY. CONCLUSIONS: An ICER of 4 million yen falls within the range of reported willingness to pay (WTP) per QALY gain (5-6.7 million yen) in Japan, and TAI is therefore found to be a cost-effective treatment strategy compared to SBC. The result should be further corroborated in future Japanese trials of TAI

Dynamical replica theoretic analysis of CDMA detection dynamics

We investigate the detection dynamics of the Gibbs sampler for code-division multiple access (CDMA) multiuser detection. Our approach is based upon dynamical replica theory which allows an analytic approximation to the dynamics. We use this tool to investigate the basins of attraction when phase coexistence occurs and examine its efficacy via comparison with Monte Carlo simulations.Comment: 18 pages, 2 figure

Statistical mechanics of clonal expansion in lymphocyte networks modelled with slow and fast variables

We study the Langevin dynamics of the adaptive immune system, modelled by a lymphocyte network in which the B cells are interacting with the T cells and antigen. We assume that B clones and T clones are evolving in different thermal noise environments and on different timescales. We derive stationary distributions and use statistical mechanics to study clonal expansion of B clones in this model when the B and T clone sizes are assumed to be the slow and fast variables respectively and vice versa. We derive distributions of B clone sizes and use general properties of ferromagnetic systems to predict characteristics of these distributions, such as the average B cell concentration, in some regimes where T cells can be modelled as binary variables. This analysis is independent of network topologies and its results are qualitatively consistent with experimental observations. In order to obtain full distributions we assume that the network topologies are random and locally equivalent to trees. The latter allows us to employ the Bethe-Peierls approach and to develop a theoretical framework which can be used to predict the distributions of B clone sizes. As an example we use this theory to compute distributions for the models of immune system defined on random regular networks.Comment: A more recent version (accepted for publication in Journal of Physics A: Mathematical and Theoretical) with improved figures, references, et

Temperature dependent Eu 3d-4f X-ray Absorption and Resonant Photoemission Study of the Valence Transition in EuNi2(Si0.2Ge0.8)2EuNi_2(Si_{0.2}Ge_{0.8})_2

We study the mixed valence transition ($T$$_{v}$ $\sim$80 K) in EuNi$_{2}$(Si$_{0.2}$Ge$_{0.8}$)$_{2}$ using Eu 3$d-4f$ X-ray absorption spectroscopy (XAS) and resonant photoemission spectroscopy (RESPES). The Eu$^{2+}$ and Eu$^{3+}$ main peaks show a giant resonance and the spectral features match very well with atomic multiplet calculations. The spectra show dramatic temperature ($T$)-dependent changes over large energies ($\sim$10 eV) in RESPES and XAS. The observed non-integral mean valencies of $\sim$2.35 $\pm$ 0.03 ($T$ = 120 K) and $\sim$2.70 $\pm$ 0.03 ($T$ = 40 K) indicate homogeneous mixed valence above and below $T$$_{v}$. The redistribution between Eu$^{2+}$$4f^7$+$[spd]^0$ and Eu$^{3+}$$4f^6$+$[spd]^1$ states is attributed to a hybridization change coupled to a Kondo-like volume collapse.Comment: 4 pages, 3 figure

Reversal of the Charge Transfer between Host and Dopant Atoms in Semiconductor Nanocrystals

We present ab initio density functional calculations that show P (Al) dopant atoms in small hydrogen-terminated Si crystals to be negatively (positively) charged. These signs of the dopant charges are reversed relative to the same dopants in bulk Si. We predict this novel reversal of the dopant charge (and electronic character of the doping) to occur at crystal sizes of order 100 Si atoms. We explain it as a result of competition between fundamental principles governing charge transfer in bulk semiconductors and molecules and predict it to occur in nanocrystals of most semiconductors.Comment: 4 pages, 4 figures (3 in color), 2 table

Long-Acting Injectable vs Oral Antipsychotics for Relapse Prevention in Schizophrenia: A Meta-Analysis of Randomized Trials

Background: While long-acting injectable antipsychotics (LAIs) are hoped to reduce high relapse rates in schizophrenia, recent randomized controlled trials (RCTs) challenged the benefits of LAIs over oral antipsychotics (OAPs). Methods: Systematic review/meta-analysis of RCTs that lasted = 6 months comparing LAIs and OAPs. Primary outcome was study-defined relapse at the longest time point; secondary outcomes included relapse at 3, 6, 12, 18, and 24 months, all-cause discontinuation, discontinuation due to adverse events, drug inefficacy (ie, relapse + discontinuation due to inefficacy), hospitalization, and nonadherence. Results: Across 21 RCTs (n = 5176), LAIs were similar to OAPs for relapse prevention at the longest time point (studies = 21, n = 4950, relative risk [RR] = 0.93, 95% confidence interval [CI]: 0.80-1.08, P =.35). The finding was confirmed restricting the analysis to outpatient studies lasting \u3e= 1 year (studies = 12, RR = 0.93, 95% CI: 0.71-1.07, P =.31). However, studies using first-generation antipsychotic (FGA)-LAIs (studies = 10, RR = 0.82, 95% CI: 0.69-0.97, P =.02) and those publishe

Tuning the 4f-state occupancy of cerium in highly correlated CeSi/ Fe multilayers: a study by x-ray absorption spectroscopy

Spectra of x-ray absorption and magnetic circular dichroism were measured at M4,5(3d) and L2,3(2p) edges of Ce in multilayers [Ce(1-x)Six/Fe]xn, with x between 0.1 and 0.65. The study uncovers the highly correlated nature of this layered system. An alpha-phase like electronic configuration of Ce is observed, with ordered magnetic moments on the 4f and 5d electrons induced by the interaction with Fe. Increasing the Si content reduces the strength of the hy-bridization between the 4f and conduction-band states which is reflected in a growing occupation and magnetic polarization of the 4f states. Variations of the shape and intensity of the L2,3-edge dichroism spectra, discussed in a simple phenomenological model, show the importance of the exchange interaction between the Ce-4f and 5d electrons, spin polarized by the interaction with Fe at the interfaces, for the electronic structure of Ce at high Si concentration and low temperature. A model of the band structure of rare-earth transition-metal compounds permits to argue that magnetic order on the Ce 4f electrons in the multilayers is due to different mechanisms: to hybridization of the Ce-4f with the Fe-3d states at low Si concentration and to intra-atomic 4f-5d exchange at high Si concentration. This is at variance with magnetic order in the intermetallics CeSi2-delta and CeSi which results from interaction between the localized 4f magnetic moments mediated by the Si-derived (s,p) conduction electrons, in competition with the Kondo effect.Comment: 31 pages, 9 figures, submitted to Phys. Rev.