Mean-field framework for performance evaluation of push-pull gossip protocols

Gossip protocols are designed to operate in very large, decentralised networks. A node in such a network bases its decision to interact (gossip) with another node on its partial view of the global system. Because of the size of these networks, analysis of gossip protocols is mostly done using simulations, but these tend to be expensive in computation time and memory consumption.We employ mean-field analysis techniques for the evaluation of gossip protocols. Nodes in the network are represented by small identical stochastic processes. Joining all nodes would result in an enormous stochastic process. If the number of nodes goes to infinity, however, mean-field analysis allows us to replace this intractably large stochastic process by a small deterministic process. This process approximates the behaviour of very large gossip networks, and can be evaluated using simple matrix-vector multiplications.     

Ion-beam irradiation into biodegradable nanofibers for tissue engineering scaffolds

Tissue engineering scaffolds require cell affinity, biodegradability, and desirable mechanical properties. Poly-_L-lactic acid (PLLA) has been investigated for tissue engineering scaffolds owing to its biodegradability and mechanical strength. Electrospun fibers have large surface area and the fibrous structure provides necessary properties for cell attachment, proliferation, differentiation, and sufficient stiffness. PLLA fibers were irradiated with Kr⁺ at an energy of 50 keV with fluences of 1 × 10¹³, 1 × 10¹⁴, and 1 × 10¹⁵ ions/cm² to improve cell affinity. Morphological change was observed by scanning electron microscopy (SEM). Surface properties were measured by FT-IR-ATR and Raman spectroscopy. L929 cell attachment to Kr⁺-irradiated fibers was evaluated. After the irradiation, the average fiber diameter decreased with high fluence. From the results of the surface analyses, the original chemical bonds were broken and new carbon structures were induced. L929 cell attachment was dramatically improved compared with non-irradiated fibers. Thus, ion-beam irradiated fibers are suitable for tissue engineering scaffolds. This technique is expected to be useful in repairing defects, such as those in nerve, vascular, and liver, in regenerative medicine.     

A hybrid radiation detector based on a plasma display panel

Recently, large-area image detectors have been investigated for X-ray imaging in medical diagnostic and other applications. In this paper, a new type of radiation detector is described, based on the integration of a photoconductor into a plasma display panel (PDP). This device, called a hybrid PDP detector, should be quite inexpensive, because it can directly leverage off the fabrication and materials technologies widely used in plasma display panels. Also, these new radiation detectors should operate under the most challenging environmental conditions, because they are inherently rugged and radiation-resistant and insensitive to magnetic fields. In this paper, we describe a hybrid digital radiation detector device, based on plasma display. The PDP panel is 7 in. in size with a 1000-μm pixel pitch, and filled with 700 Torr of Xe gas; the hybrid PDP panel is of the same structure, except for the photoconductor deposit. The glass absorption, dark current, X-ray sensitivity, and linearity as a function of electric field were measured to investigate its electrical properties. From the results, stabilized dark current density and significant X-ray sensitivity were obtained with both panels; however, the hybrid PDP detector showed better characteristics than the PDP detector. It also had good signal response and linearity. The hybrid digital radiation detector device based on a plasma display seems to be a promising technology for use in radiology and dynamic moving imaging.     

For better or worse? Coregulation of couples’ cortisol levels and mood states.

Although a majority of adults live with a close relationship partner, little is known about whether and how partners’ momentary affect and physiology covary, or “coregulate.” This study used a dyadic multilevel modeling approach to explore the coregulation of spouses’ mood states and cortisol levels in 30 married couples who sampled saliva and reported on mood states 4 times per day for 3 days. For both husbands and wives, own cortisol level was positively associated with partner’s cortisol level, even after sampling time was controlled. For wives, marital satisfaction weakened the strength of this effect. Partner’s negative mood was positively associated with own negative mood for both husbands and wives. Marital satisfaction fully moderated this effect, reducing the strength of the association between one’s own and one’s partner’s negative mood states. Spouses’ positive moods were not correlated. As expected, within-couple coregulation coefficients were stronger when mood and cortisol were sampled in the early morning and evening, when spouses were together at home, than during the workday. The results suggest that spouses’ fluctuations in negative mood and cortisol levels are linked over several days and that marital satisfaction may buffer spouses from their partners’ negative mood or stress state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of surgical menopause on psychological characteristics and lipid levels: The Healthy Women Study.

The authors examined the effects of surgical menopause, with or without hormone replacement therapy (HRT), on psychosocial functioning and lipid levels in a population-based study of initially premenopausal women. Within 5 years of study entry, 28 women underwent hysterectomy, with 9 retaining their ovaries and 19 having bilateral salpingo oophorectomy (BSO), and with 173 premenopausal women as a comparison group. Women undergoing hysterectomy reported fewer stress symptoms and a more optimistic attitude at follow-up, whereas BSO cases without HRT had lower mean total high-density lipoprotein (HDL) and HDL2, relative to premenopausal women. Subject to limited power, the authors' findings suggest that surgical menopause among middle-aged women does not lead to negative psychological outcomes but that BSO in the absence of hormone use has significant adverse effects on total HDL and HDL2. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Complex Diagnostics of Non-Specific Intellectual Developmental Disorder

Intellectual development disorder (IDD) is characterized by a general deficit in intellectual and adaptive functioning. In recent years, there has been a growing interest in studying the genetic structure of IDD. Of particular difficulty are patients with non-specific IDD, for whom it is impossible to establish a clinical diagnosis without complex genetic diagnostics. We examined 198 patients with non-specific IDD from 171 families using whole-exome sequencing and chromosome microarray analysis. Hereditary forms of IDD account for at least 35.7% of non-specific IDD, of which 26.9% are monogenic forms. Variants in the genes associated with the BAF (SWI/SNF) complex were the most frequently identified. We were unable to identify phenotypic features that would allow differential diagnosis of monogenic and microstructural chromosomal rearrangements in non-specific IDD at the stage of clinical examination, but due to its higher efficiency, exome sequencing should be the diagnostic method of the highest priority study after the standard examination of patients with NIDD in Russia.     

Comparison of some characteristics of thin‐film‐electroluminescent ZnS: Er,F planar and edge emitters

Abstract— The following main differences have been revealed in the characteristics of an edge thin‐film‐electroluminescent ZnS: Er,F emitter compared to those of a similar planar emitter: (1) the 1.535‐μm band more highly dominates over other bands in the EL spectrum; (2) the voltage (V) dependence of the intensity of this band is the strongest; (3) the 1.535‐μm band narrows with increasing voltage and its frequency. The above differences are explained, firstly, by smaller optical losses in the ZnS: Er,F film for the near‐infrared emission than for the visible one and, secondly, by an optical amplification over the 1.535‐μm band in the edge emitter.     

Determining the upsetting parameters for the ends of drilling pipe

By the slip-line method, analytical formulas are derived for the upsetting force and the length of the internal transition zone. The calculation results obtained for specific upsetting conditions correspond to experimental data. The proposed method of determining the parameters for upsetting of the ends of drilling pipe have been successfully used in industrial conditions.     

Degradation of a Foam‐Promoting Barley Protein by a Proteinase from Brewing Yeast

The degradation of a major protein component in beer, the lipid transfer protein (LTP1), by the yeast proteinase A was determined. Another major protein fraction in beer, the protein Z‐fraction, was not degraded by this enzyme. Protein preparations from beer and barley containing LTP1 were examined for degradation by proteinase A using SDS‐PAGE, immunoblotting and RP‐HPLC. LTP1 from barley was completely resistant to proteinase A, whereas LTP1 concentrated from beer was cleaved. We conclude that LTP1 was modified during the brewing process, thus rendering it more susceptible to proteinase A degradation.