399 research outputs found
Neuronal avalanches of a self-organized neural network with active-neuron-dominant structure
Neuronal avalanche is a spontaneous neuronal activity which obeys a power-law
distribution of population event sizes with an exponent of -3/2. It has been
observed in the superficial layers of cortex both \emph{in vivo} and \emph{in
vitro}. In this paper we analyze the information transmission of a novel
self-organized neural network with active-neuron-dominant structure. Neuronal
avalanches can be observed in this network with appropriate input intensity. We
find that the process of network learning via spike-timing dependent plasticity
dramatically increases the complexity of network structure, which is finally
self-organized to be active-neuron-dominant connectivity. Both the entropy of
activity patterns and the complexity of their resulting post-synaptic inputs
are maximized when the network dynamics are propagated as neuronal avalanches.
This emergent topology is beneficial for information transmission with high
efficiency and also could be responsible for the large information capacity of
this network compared with alternative archetypal networks with different
neural connectivity.Comment: Non-final version submitted to Chao
Error Correction for Cooperative Data Exchange
This paper considers the problem of error correction for a cooperative data
exchange (CDE) system, where some clients are compromised or failed and send
false messages. Assuming each client possesses a subset of the total messages,
we analyze the error correction capability when every client is allowed to
broadcast only one linearly-coded message. Our error correction capability
bound determines the maximum number of clients that can be compromised or
failed without jeopardizing the final decoding solution at each client. We show
that deterministic, feasible linear codes exist that can achieve the derived
bound. We also evaluate random linear codes, where the coding coefficients are
drawn randomly, and then develop the probability for a client to withstand a
certain number of compromised or failed peers and successfully deduce the
complete message for any network size and any initial message distributions
Protective effect of astragalus injection against myocardial injury in septic young rats via inhibition of JAK/STAT signal pathway and regulation of inflammation
Purpose: To investigate the protective effect of astragalus injection against myocardial injury in septic young rats, and the underlying mechanism of action.
Methods: Seventy-two healthy Sprague Dawley (SD) rats were randomly selected and used to establish a young rat model of sepsis. The young rats were randomly divided into 3 groups: sham, model and astragalus injection groups. Each group had 24 young rats. Serum cardiac troponin I (cTnI), IL-10, IL-6, JAK2 and STAT3 were measured after op.
Results: Compared with sham group, serum cTnI level in the model group was significantly higher, while serum cTnI level of the drug group was significantly lower than that of the model group (p < 0.05). Compared with model group, the level of IL-10 in the myocardial tissue of the drug group was significantly elevated, while IL-6 level was lower (p < 0.05). Relative to sham rats, myocardial JAK2 and STAT3 protein levels in model rats were high. However, myocardial JAK2 and STAT3 proteins in the drug-treated rats were significantly downregulated, relative to model rats (p < 0.05).
Conclusion: Astragalus injection upregulates IL-10 and IL-6 in rats by inhibiting the activation of JAK/STAT signal pathway, and via maintenance of pro-inflammation/anti-inflammation balance. Thus, astragalus exerts protective effect against myocardial injury in sepsis, and can potentially be developed for use as such in clinical practice.
Keywords: Astragalus injection, JAK/STAT signal pathway, Pro-inflammatory/anti-inflammatory imbalance, Sepsis, Myocardial injur
Bis(formato-κO)bis[1-(pyridin-2-yl)ethanone oxime-κ2 N,N′]nickel(II)
In the title compound, [Ni(HCOO)2(C7H8N2O)2], the Ni atom is six-coordinated by four N atoms from two oxime ligands and by two O atoms from two formate ions in a distorted octahedral geometry, with the oxime-N atoms mutually trans. The molecular conformation is stabilized by intramolecular O—H⋯O hydrogen bonds
Chlorido[1-(pyridin-2-yl)ethanone oximato-κ2 N,N′][1-(2-pyridyl)ethanone oxime-κ2 N,N′]copper(II) trihydrate
In the title compound, [Cu(C7H7N2O)Cl(C7H8N2O)]·3H2O, the metal ion is five-coordinated by the N atoms from the 1-(pyridin-2-yl)ethanone oximate and 1-(pyridin-2-yl)ethanone oxime ligands and by the chloride anion in a distorted square-pyramidal geometry. The distortion parameter is 0.192. The two organic ligands are linked by an intramolecular O—H⋯O hydrogen bond. In the crystal, molecules are linked by O—H⋯O and O—H⋯Cl hydrogen bonds. The title compound is the hydrated form of a previously reported structure [Wu & Wu (2008 ▶). Acta Cryst. E64, m828]. There are only slight variations in the molecular geometries of the two compounds
An optimized encoding algorithm for systematic polar codes
Many different encoding algorithms for systematic polar codes (SPC) have been introduced since SPC was proposed in 2011. However, the number of the computing units of exclusive OR (XOR) has not been optimized yet. According to an iterative property of the generator matrix and particular lower triangular structure of the matrix, we propose an optimized encoding algorithm (OEA) of SPC that can reduce the number of XOR computing units compared with existing non-recursive algorithms. We also prove that this property of the generator matrix could extend to different code lengths and rates of the polar codes. Through the matrix segmentation and transformation, we obtain a submatrix with all zero elements to save computation resources. The proportion of zero elements in the matrix can reach up to 58.5{\%} from the OEA for SPC when the code length and code rate are 2048 and 0.5, respectively. Furthermore, the proposed OEA is beneficial to hardware implementation compared with the existing recursive algorithms in which signals are transmitted bidirectionally
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