N1‐allyl‐3‐substituted‐6,7‐dimethyl‐1,2‐dihydro‐2‐quinoxalinone as key intermediate for new acyclonucleosides and their regioisomer O‐analogues

The key intermediates allyloxyquinoxaline 2a–c and N‐allylquinoxaline 3a–c were used to synthesize a number of acyclonucleosides whose chemical modifications include quinoxaline ring and the acyclic part is either N¹‐propanediol or 3‐hydroxy‐ propyl substituents and their O‐analogues. These compounds were characterized by elemental analysis, MALDI MS, and NMR data. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:280–288, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20203     

Dielectric Properties of Polyimide‐Mica Hybrid Films

Summary: Polyimide‐mica hybrid films were prepared via ultrasonic dispersion and in situ polymerization process from a solution of a polyimide precursor and mica in N,N‐dimethylacetamide, and their structure was characterized by FTIR and XRD techniques. The dependence of dielectric properties, such as dielectric constant and electrical breakdown strength, of the hybrid films on the content of mica was studied at room and cryogenic temperatures. The results show that the dielectric constant of PI‐mica hybrid films decreases with the increase of the mica content at temperatures from −150 to 150 °C and at frequency range from 1 kHz to 1 MHz. It was found that the cryogenic electrical breakdown strength of the PI‐mica hybrid films could meet the requirements of cryogenic insulating materials.

Effect of frequency on the dielectric constant of PI‐mica hybrid films at 140 °C at the frequency from 1 kHz to 1 MHz.     

Mastery of Cultural Conditions and Physico-chemical Properties Improves the Production and the Catalytic Efficiency of bglG

Stachybotrys microspora is a filamentous fungus secreting multiple β-glucosidases. Two of them were characterized. The third one, named bglG, was also characterized and used for various investigations. The current work undertakes the plausible role played by some cultural conditions and physico-chemical properties to improve bglG time course synthesis and also its catalytic efficiency. Indeed, bglG time course synthesis is slightly affected by light, but it is clearly affected by aeration and presence of baffle. On the same case, optimization of substrate and enzyme concentration contributes to the improvement of the catalytic efficiency of bglG. This biocatalyst tolerates a high ionic strength during its activity assay; β-mercaptoethanol increases the enzymatic rate. BglG has the capacity to hydrolyse efficiently oleuropéin, with a recovery of 88 %.     

On the interplay of network structure and routing strategies in scale-free networks

In this paper, we examine how the structural characteristics of network topologies affect the network performance, and we examine the interplay between structural characteristics of network topologies and routing strategies. We consider routing strategies subject to practical constraints (router technology) and economic considerations (link costs) at layer 3. We propose two new routing methods suitable for implementation in large networks and examine various routing strategies (local, global, and hybrid) with tunable parameters and explore how they can enhance the network performance. We find that there exists an optimal range of values for the tunable parameters to achieve high network performance which depends on the structural properties of the network topology. We also show that our proposed routing scheme, which requires minimum local information, achieves high network performance.     

An equilibrium model of how regulative and normative institutions influence micro-economic and organizational behavior

This paper investigates how pre-existing institutions foster economic development through trade. A non-cooperative game-theoretic model is proposed that combines three strands of social science: economics, political science, and sociology. Idealized market participants follow rational decision theory within a reward structure that embodies two types of institutions. Regulative institutions operate on threat of punishment, and normative institutions on perceptions of what is good and right. This composite model allows a more quantitative analysis of the question, raised by Douglas North, of how societies diverge from the efficient state predicted by classical micro-economics. The main finding is that value can be created by different types of institution even when they are imperfect, and the range of minimum–maximum effectiveness varies with the types of economic transactions that are technologically possible. It is hoped that further refinements of the model will yield greater understanding of how the success of societies and organizations can be predicted by a few simple rules.     

EDCCS: effective deterministic clustering scheme based compressive sensing to enhance IoT based WSNs

Wireless Networks - The problem of Data acquisition in large distributed Wireless Sensor Networks (WSNs) scale is a hindrance in the growth of the Internet of Things (IoT). Recently, the...