Recent Biophysical Issues About the Preparation of Solute-Filled Lipid Vesicles

Here we report some recent biophysical issues on the preparation of solute-filled lipid vesicles and their relevance to the construction of “synthetic cells.” First, we introduce the “semi-synthetic minimal cells” as the liposome-based cell-like systems, which contain a minimal number of biomolecules required to display simple and complex biological functions. Next, we focus on recent aspects related to the construction of synthetic cells. Emphasis is given to the interplay between the methods of synthetic cell preparation and the physics of solute encapsulation. We briefly introduce the notion of structural and compositional “diversity” in synthetic cell populations.     

In‐Situ Observation of the Formation of MnS during Solidification of High Sulphur Steels

A Confocal Scanning Laser Microscope equipped with a gold image furnace was used to directly observe the precipitation of MnS during solidification of high sulphur steels under isothermal conditions in the temperature region 1440 to 1480°C on the free surface of the steel melt. For the case of Al‐killed steels, below 1480°C MnS particles were found to precipitate with Fe forming simultaneously around them. This MnS containing structure continued to grow rapidly (264 μm/s) as a surface film. The film gradually changed, as the level of S in the melt decreased, into a eutectic structure (with lamella spacing of 2 μm) as predicted by thermodynamics. In Si‐ killed steels there was significantly lower tendency to form MnS both in terms of time until precipitation occurred and growth rate.     

Potential applications of poly(vinyl alcohol)‐congo red aqueous solutions and hydrogels as liquids for hydraulic fracturing

The authors report on the viscoelastic characterization of guar hydrogels obtained through complexation reactions with borax ions. These gels are compared with hydrogels obtained from poly(vinyl alcohol) of different degree of hydrolysis through complexation reactions with congo red. The effect of the degree of hydrolysis and both, the concentration of PVA and the concentration of congo red, on the viscoelastic properties of the hydrogels is analyzed. The potential use of the PVA‐based hydrogels as hydraulic fracturing liquids is discussed in relation to the commonly used fracturing liquid based on the guar–borax system. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and Evaluation of Voltage-Gated Sodium Channel Blocking Pyrroline Derivatives Endowed with Both Antiarrhythmic and Antioxidant Activities

Under the hypothesis that cardioprotective agents might benefit from synergism between antiarrhythmic activity and antioxidant properties, a small series of mexiletine analogues were coupled with the 2,2,5,5-tetramethylpyrroline moiety, known for its antioxidant effect, in order to obtain dual-acting drugs potentially useful in the protection of the heart against post-ischemic reperfusion injury. The pyrroline derivatives reported herein were found to be more potent as antiarrhythmic agents than mexiletine and displayed antioxidant activity. The most interesting tetramethylpyrroline congener, a tert-butyl-substituted analogue, was at least 100 times more active as an antiarrhythmic than mexiletine.     

A New Tool to Study Parkinsonism in the Context of Aging: MPTP Intoxication in a Natural Model of Multimorbidity

The diurnal rodent Octodon degus (O. degus) is considered an attractive natural model for Alzheimer’s disease and other human age-related features. However, it has not been explored so far if the O. degus could be used as a model to study Parkinson’s disease. To test this idea, 10 adult male O. degus were divided into control group and MPTP-intoxicated animals. Motor condition and cognition were examined. Dopaminergic degeneration was studied in the ventral mesencephalon and in the striatum. Neuroinflammation was also evaluated in the ventral mesencephalon, in the striatum and in the dorsal hippocampus. MPTP animals showed significant alterations in motor activity and in visuospatial memory. Postmortem analysis revealed a significant decrease in the number of dopaminergic neurons in the ventral mesencephalon of MPTP animals, although no differences were found in their striatal terminals. We observed a significant increase in neuroinflammatory responses in the mesencephalon, in the striatum and in the hippocampus of MPTP-intoxicated animals. Additionally, changes in the subcellular expression of the calcium-binding protein S100β were found in the astrocytes in the nigrostriatal pathway. These findings prove for the first time that O. degus are sensitive to MPTP intoxication and, therefore, is a suitable model for experimental Parkinsonism in the context of aging.     

Mechanisms for SLA provisioning in cloud-based service providers

A challenge in cloud resource management is to design self-adaptable solutions capable to react to unpredictable workload fluctuations and changing utility principles. This paper analyzes the problem from the perspective of an Application Service Provider (ASP) that uses a cloud infrastructure to achieve scalable provisioning of its services in the respect of QoS constraints.First we draw a taxonomy of IaaS provider and use the identified features to drive the design of four autonomic service management architectures differing on the degree of control an ASP have on the system. We implemented two of this solutions and related mechanism to test five different resource provisioning policies. The implemented testbed has been evaluated under a realistic workload based on Wikipedia access traces on Amazon EC2 platform.The experimental evaluation performed confirms that: the proposed policies are capable to properly dimension the system resources making the whole system self-adaptable respect to the workload fluctuation. Moreover, having full control over the resource management plan allow to save up to the 32% of resource allocation cost always in the respect of SLA constraints.     

Logic and Interaction: Foreword to the Special Issue

Journal of Logic, Language and Information -     

Long memory time series forecasting by using genetic programming

Real-world time series have certain properties, such as stationarity, seasonality, linearity, among others, which determine their underlying behaviour. There is a particular class of time series called long-memory processes, characterized by a persistent temporal dependence between distant observations, that is, the time series values depend not only on recent past values but also on observations of much prior time periods. The main purpose of this research is the development, application, and evaluation of a computational intelligence method specifically tailored for long memory time series forecasting, with emphasis on many-step-ahead prediction. The method proposed here is a hybrid combining genetic programming and the fractionally integrated (long-memory) component of autoregressive fractionally integrated moving average (ARFIMA) models. Another objective of this study is the discovery of useful comprehensible novel knowledge, represented as time series predictive models. In this respect, a new evolutionary multi-objective search method is proposed to limit complexity of evolved solutions and to improve predictive quality. Using these methods allows for obtaining lower complexity (and possibly more comprehensible) models with high predictive quality, keeping run time and memory requirements low, and avoiding bloat and over-fitting. The methods are assessed on five real-world long memory time series and their performance is compared to that of statistical models reported in the literature. Experimental results show the proposed methods’ advantages in long memory time series forecasting.