Creativity and simplicity

For many scientists, human intelligence and, in particular, its creative potential seem to consist of processes that cannot be automated by means of a computer. As already shown with fractal geometry, this short note tries to show that the iteration and combination of very elementary operations can give very complex behaviors and shapes. It gives some practical examples to encourage reader involvement and new experiments, particularly in classroom settings.     

Protein tyrosine kinase activity as a prognostic parameter in breast cancer, a pilot study

The interaction of omega (benzodiazepine) modulatory drugs with transiently expressed alpha 1 beta 2 gamma 2 and alpha 5 beta 2 gamma 2 forms of the rat GABAA receptor was investigated using [3H]flumazenil as a probe in in vitro radioligand binding assays. The imidazopyridines alpidem and zolpidem exhibited pronounced selectivity for the alpha 1- compared to the alpha 5-containing construct, whereas omega (benzodiazepine) site modulatory compounds from other chemical series including diazepam, tetrazepam, zopiclone, triazolam, bretazenil and midazolam behaved as relatively non-selective drugs. In the presence of 10 microM gamma-aminobutyric acid (GABA) the potencies of diazepam, flunitrazepam and midazolam to inhibit [3H]flumazenil binding to the alpha 1-construct were increased 3 to 5 fold, whereas with 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate methyl ester a 2.5-fold reduction in potency was observed. Similar modulatory effects of GABA were obtained with these drugs, using the alpha 5-construct. We suggest that these GABA shift determinations of [3H]flumazenil binding can be used as a rapid test to evaluate the intrinsic activities of omega modulatory compounds.     

Molecular mobility in starchy materials studied by electron spin resonance

Phase transitions in hydrated starch–sorbitol system were investigated both by molecular (electron spin resonance, ESR) and macroscopic (differential scanning calorimetry, DSC) methods. In rapid‐tumbling region, one did not observe the same phenomena by DSC and by ESR. The transitions observed by ESR, which seemed to reflect more the interactions probe–matrix than plasticization, probably corresponded to the interactions probe–sorbitol. For system concentrated in plasticizer, it was conceivable to admit that a demixion of sorbitol occurred. In slow‐tumbling region, a correspondence in temperature mobility changes measured by mechanical spectroscopy and ESR was observed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 990–997, 2003     

ω‐Phthalimidoalkyl Aryl Ureas as Potent and Selective Inhibitors of Cholesterol Esterase

Cholesterol esterase (CEase), a serine hydrolase thought to be involved in atherogenesis and thus coronary heart disease, is considered as a target for inhibitor development. We investigated recombinant human and murine CEases with a new fluorometric assay in a structure–activity relationship study of a small library of ω‐phthalimidoalkyl aryl ureas. The urea motif with an attached 3,5‐bis(trifluoromethyl)phenyl group and the aromatic character of the ω‐phthalimide residue were most important for inhibitory activity. In addition, an alkyl chain composed of three or four methylene groups, connecting the urea and phthalimide moieties, was found to be an optimal spacer for inhibitors. The so‐optimized compounds 2 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(3‐(1,3‐dioxoisoindolin‐2‐yl)propyl)urea] and 21 [1‐(3,5‐bis(trifluoromethyl)phenyl)‐3‐(4‐(1,3‐dioxoisoindolin‐2‐yl)butyl)urea] exhibited dissociation constants (K_i) of 1–19 μm on the two CEases and showed either a competitive ( 2 on the human enzyme and 21 on the murine enzyme) or a noncompetitive mode of inhibition. Two related serine hydrolases—monoacylglycerol lipase and fatty acid amide hydrolase—were inhibited by ω‐phthalimidoalkyl aryl ureas to a lesser extent.     

Image recovery from exponential blurring

We study the following type of filtering problem: consider an image on ², that is, a nonnegative function on the vertices of a grid, which represents the brightness at each of these points. We assume that there is, however, a smudging effect. That is, what ought to be a point of light becomes the point together with a halo about it, visualized by a distribution of light which is greatest at the point itself and decreases with the distance. So what we actually see is a blurry image. In this article we investigate methods for clearing up the image, i.e. reconstructing the original function from the blurry haloed image when the halo decays exponentially, and also for some haloes with small finite support. This task is usually performed by inverting the convolution operator induced by the halo (that is, by Fourier analysis). We introduce a different recovery procedure, based upon a family of filtering operators that change from point to point. For the finitely supported haloes, this procedure compares favorably with the Fourier methods. Moreover, in principle it is more general, because it does not require assumptions of invariance under translation. In full generality, however, we are able to recover images not on grids, but only on trees.     

Service robots in hospitals: new perspectives on niche evolution and technology affordances

Changing demands in society and the limited capabilities of health systems have paved the way for robots to move out of industrial contexts and enter more human-centered environments such as health care. We explore the shared beliefs and concerns of health workers on the introduction of autonomously operating service robots in hospitals or professional care facilities. By means of Q-methodology, a mixed research approach specifically designed for studying subjective thought patterns, we identify five potential end-user niches, each of which perceives different affordances and outcomes from using service robots in their working environment. Our findings allow for better understanding resistance and susceptibility of different users in a hospital and encourage managerial awareness of varying demands, needs, and surrounding conditions that a service robot must contend with. We also discuss general insights into presenting the Q-methodology results and how an affordance-based view could inform the adoption, appropriation, and adaptation of emerging technologies.     

You like it,you learn it: affectivity and learning in competitive social role play gaming

Despite the alleged ability of digital game-based learning (DGBL) to foster positive affect and in turn improve learning, the link between affectivity and learning has not been sufficiently investigated in this field. Regarding learning from team-based games with competitive elements, even less is known about the relationship between competitiveness (as a dispositional trait) and induced positive affect. In this media comparison study with between-subject design, participants (N?=?325; high school and college students) learned about the EU’s policy agenda by means of a debate-based method delivered through one of three educational media: a) through a social role-playing game with competitive elements played on computers, b) through a very similar game played without computers and c) through a non-game workshop. Unlike many previous DGBL studies, this study used participant randomization and strived to address the teacher effect and the length of exposure effect, while also using the same learning materials and a very similar educational method for all three treatments. Both games induced comparatively higher generalized positive affect and flow. Participants also learned more with the games. Positive affect, but not flow, mediated the influence of educational media on learning gains. Participants’ competitiveness was partly related to positive affect and experiencing flow but unrelated to learning gains. These outcomes held both when the game was played using computers, as well as without them. The study indicates that the ability of an educational intervention to instigate positive affect is an important feature that should be considered by educational designers.     

Dimensional analysis of Ni‐NiO grains at anode/electrolyte interface for SOFC during redox reaction

Upon reduction and re‐oxidization, the interface of a microtubular solid oxide fuel cell (MTSOFC) anode/electrolyte was structurally analyzed using a dual beam focused ion beam/scanning electron microscope (FIB/SEM) and scanning transmission electron microscopy combined with energy dispersive X‐ray spectrometer (STEM‐EDX). The bulk volume of the dense NiO phase dramatically contracted upon reduction, while the YSZ phases are completely unaffected. No cracks or particle detachment are observed either at the interface of the anode/electrolyte or in the anode backbone. Compared with the initial NiO state (as‐prepared), the area of Ni phase contracts by 22.6%‐83.7%, depending on the grain size.     

Characterization of a new miniCAST with diffusion flame and premixed flame options: Generation of particles with high EC content in the size range 30 nm to 200 nm

Flame-generated soot from miniCAST burners is increasingly being used in academia and industry as engine exhaust soot surrogate for atmospheric studies and instrument calibration. Previous studies have found that elemental carbon (EC) content of miniCAST soot is proportional to the mean particle size. Here, the characterization of a prototype miniCAST generator (5201 Type BC), which was designed to decouple the soot composition from the particle size and produce soot particles with high EC and BC content in a large size range, is reported. This prototype may operate either in a diffusion-flame or a partially premixed-flame mode, an option that was not available in former models. It was confirmed that soot properties, such as EC content and Ångström absorption exponent (AAE), were linked to the overall flame composition. In particular, combustion under fuel-rich conditions provided particles with size coupled to the EC fraction and AAE, i.e. smaller particles exhibited a lower EC fraction and higher AAE. In contrast, with fuel-lean diffusion flames and especially with premixed flames under near overall stoichiometric conditions small particles (down to 30?nm) with high EC/TC ratios (>60%) and low AAE (≈1.4) could be generated even without any thermal after-treatment. This new source might thus serve in the future as a useful surrogate for engine exhaust emissions and help to improve calibration procedures of common aerosol instruments.

Copyright © 2018 The Author(s). Published with license by Taylor & Francis Group, LLC