Necessary and sufficient conditions for strong stability of distributed parameter systems

In this paper we propose definitions for strong stabilizability and strong detectability of infinite-dimensional control systems. We show that these definitions are appropriate by showing that they can be used to give necessary and sufficient conditions for the strong stability of a system in terms of its input-output stability. As an application, we discuss the strong stability of the feedback interconnection of two strongly stabilizable and strongly detectable systems.     

Sugarcane bagasse ash as a reinforcing filler in thermoplastic elastomers: Structural and mechanical characterizations

The incorporation of residues as reinforcing fillers in polymer composites has emerged as a viable solution, enabling improvements in the mechanical properties of these materials, and has also resulted in a reduction in the cost of the final product. In this work, sugarcane bagasse ash (SBA) was used as a reinforcing filler in comparison with commercial silica (CS) in thermoplastic elastomers prepared from the compatibility of low‐density polyethylene (LDPE) with natural rubber (NR). The composites were obtained by a physical mixture of LDPE and NR with different proportions of CS and SBA using a Haake rotational rheometer. The samples were analyzed by Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and tensile testing. The results show that SBA has similar properties to CS, thus making its use feasible as a reinforcing filler in thermoplastic elastomers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41466.     

Use of digoxigenin-labeled RNA probe to test hepatitis A virus antiviral drugs

A nucleic acid hybridization assay was used to evaluate inhibitory activity of antiviral compounds against hepatitis A virus (HAV) in cell culture and compared to radioimmunoassay by analysis of variance procedure. The 5' genomic end of the HM-175 strain was used as digoxigenin-labeled RNA probe. Dot-blot examination showed a reduction of detectable HAV RNA in infected cells when treated with amphotericin B. An antiviral dose-effect was shown by statistical analysis of densitometric measures of hybridization signals. Comparison between molecular hybridization assay and radioimmunoassay by analysis of variance procedure showed the equivalence of both methods. Data previously obtained on selected drugs by antigen and infectious titres determinations were confirmed by hybridization assay and make possible digoxigenin-labeled RNA probe use to measure an antiviral dose-effect for screening of hepatitis A antiviral compounds.     

Category-specific naming impairments? Yes

Recently, Stewart, Parkin, and Hunkin (1992) have questioned previously reported cases of selective damage in processing items from categories of animate objects, arguing that there has been a lack of adequate control for visual familiarity, visual complexity, and name frequency of the stimuli employed. When re-testing Michelangelo (see Sartori & Job, 1988), one of the patients cited by Stewart et al. (1992), with a set of materials matched on all three factors, the asymmetry in naming animal and artefact items still remains. An analogous pattern is obtained when--in addition to such factors--the visual similarity within the sub-sets of animals and artefacts is taken into account. These results constitute empirical evidence for category-specific impairments and cannot be interpreted as being due to isolated or conjoint effects of visual familiarity, visual complexity, or name frequency.     

Moving faces, looking places: Validation of the Amsterdam Dynamic Facial Expression Set (ADFES).

We report two studies validating a new standardized set of filmed emotion expressions, the Amsterdam Dynamic Facial Expression Set (ADFES). The ADFES is distinct from existing datasets in that it includes a face-forward version and two different head-turning versions (faces turning toward and away from viewers), North-European as well as Mediterranean models (male and female), and nine discrete emotions (joy, anger, fear, sadness, surprise, disgust, contempt, pride, and embarrassment). Study 1 showed that the ADFES received excellent recognition scores. Recognition was affected by social categorization of the model: displays of North-European models were better recognized by Dutch participants, suggesting an ingroup advantage. Head-turning did not affect recognition accuracy. Study 2 showed that participants more strongly perceived themselves to be the cause of the other's emotion when the model's face turned toward the respondents. The ADFES provides new avenues for research on emotion expression and is available for researchers upon request. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Waterpipe smoking and nicotine exposure: a review of the current evidence.

The waterpipe, also known as shisha, hookah, narghile, goza, and hubble bubble, has long been used for tobacco consumption in the Middle East, India, and parts of Asia, and more recently has been introduced into the smokeless tobacco market in western nations. We reviewed the published literature on waterpipe use to estimate daily nicotine exposure among adult waterpipe smokers. We identified six recent studies that measured the nicotine or cotinine levels associated with waterpipe smoking in four countries (Lebanon, Jordan, Kuwait, and India). Four of these studies directly measured nicotine or cotinine levels in human subjects. The remaining two studies used smoking machines to measure the nicotine yield in smoking condensate produced by the waterpipe. Meta-analysis of the human data indicated that daily use of the waterpipe produced a 24-hr urinary cotinine level of 0.785 microg/ml (95% CI = 0.578-0.991 microg/ml), a nicotine absorption rate equivalent to smoking 10 cigarettes/day (95% CI = 7-13 cigarettes/day). Even among subjects who were not daily waterpipe smokers, a single session of waterpipe use produced a urinary cotinine level that was equivalent to smoking two cigarettes in one day. Estimates of the nicotine produced by waterpipe use can vary because of burn temperature, type of tobacco, waterpipe design, individual smoking pattern, and duration of the waterpipe smoking habit. Our quantitative synthesis of the limited human data from four nations indicates that daily use of waterpipes produces nicotine absorption of a magnitude similar to that produced by daily cigarette use.     

Synthesis of very highly dispersed platinum catalysts supported on carbon xerogels by the strong electrostatic adsorption method

Highly dispersed Pt/carbon xerogel catalysts are obtained by applying the “strong electrostatic adsorption” (SEA) of hexachloroplatinic acid to carbon xerogels (PZC = 9.4) and platinum tetraammine chloride to oxidized carbon xerogels (PZC = 2.4). After the reduction step, all these Pt/carbon xerogel catalysts display a very high level of metal dispersion: very small platinum particles (1.1–1.3 nm) are observed by TEM. Pt particle sizes obtained by CO chemisorption are in good agreement with TEM micrographs, which shows that the metal is accessible to reactants. These Pt/carbon xerogel catalysts are very active for the hydrogenation of benzene into cyclohexane.     

The immunosuppressive effect of concanavalin A in monkeys

These studies were performed to evaluate the immunosuppressive effect of concanavalin A (ConA) in monkeys. Bonnet monkeys (Macaca radiata) weighing between 2.5-3.5 kg were used. Following the exchange of full thickness skin allografts in randomly selected animals, gross and histopathological studies of the rejection reaction were performed. Gross observations showed the allograft reaction in control animals to be a well defined phenomenon occurring at 9.0 +/- 0.7 days. In contrast the rejection process in animals that received i.v. ConA was a poorly defined prolonged process occurring at 14.8 +/- 3.9 days (single 75-mg dose of ConA), and 19.0 +/- 2.2 days (75 mg 1 day before and 25 mg 3 days after grafting). In monkeys that received the double dose schedule of ConA, histopathological studies showed distinct retardation of the rejection reaction with reduced lymphocytic infiltration of the graft-host junction. Control grafts showed almost complete rejection in 7-9 days while allografts on ConA-treated animals showed corresponding degrees of destruction only by the 15th day. These studies indicate that ConA does have an immunosuppressive effect in vivo in monkeys. The local and systemic toxic effects of ConA encountered in these animals have been reported and its haematological effects in vivo briefly described.     

Dissipative Self‐Assembly of Peptides

In molecular self‐assembly, molecules interact with each other by non‐covalent interactions to form larger structures. The process occurs in‐equilibrium, which means that molecules can leave the assembly and reassemble elsewhere, but that occurs on average with equal rates. For self‐assembly, peptides have proven to be a particularly useful building block, in part because of their versatility. Biology also uses self‐assembly to create functional materials. For example, components of the cytoskeleton, like actin filament and microtubules, are self‐assembled proteins. In other words, biology uses the same building blocks and design rules as supramolecular chemists to create functional structures. However, biological assemblies are vastly more complex than their synthetic counterparts. The discrepancy is in part because proteins are more complex than the peptides we use as building blocks. Another contributing factor to the difference in complexity is that most assemblies in living systems exist out of equilibrium. To use peptides for complex functions as biology does, we should understand and be able to create peptide assemblies out of equilibrium. In this work, we review recent advances towards the creation of peptide assemblies that exist out of equilibrium driven by an external energy source.