Physical properties of muffins sweetened with steviol glycosides as the sucrose replacement

Overconsumption of sweets contributes to increasing obesity among children and adults. Functional food brings an opportunity to improve nutritional value of commonly eaten products, e.g., pastry products. New trends in the food industry tend to produce low-calorie products by replacing sugar or fat with additives having pro-health benefits. The aim of this study was to determine the effect of replacing sucrose with steviol glycosides (natural non-caloric sweetener) on the quality properties of bakery products. The analysis of muffin’s texture, color, cooking yield, browning index, and sensory analysis were performed. The study showed that a 25% addition of steviol sweetener (as a sucrose replacement) was the most appropriate modification of the basic formula. The resulting muffins gained sensory attractiveness and health-promoting qualities. Moreover, the study showed that a reduction of sucrose in excess of 50% had a negative impact on the quality of muffins and their sensory profiles.     

The NavChair Assistive Wheelchair Navigation System.

The NavChair Assistive Wheelchair Navigation System [19] is being developed to reduce the cognitive and physical requirements of operating a power wheelchair for people with wide ranging impairments that limit their access to powered mobility. The NavChair is based on a commercial wheelchair system with the addition of a DOS-based computer system, ultrasonic sensors, and an interface module interposed between the joystick and power module of the wheelchair. The obstacle avoidance routines used by the NavChair in conjunction with the ultrasonic sensors are modifications of methods originally used in mobile robotics research. The NavChair currently employs three operating modes: general obstacle avoidance, door passage, and automatic wall following. Results from performance testing of these three operating modes demonstrate their functionality. In additional to advancing the technology of smart wheelchairs, the NavChair has application to the development and testing of "shared control" systems where a human and machine share control of a system and the machine can automatically adapt to human behaviors.     

Modeling rough granular computing based on approximation spaces

The results reported in this paper create a step toward the rough set-based foundations of data mining and machine learning. The approach is based on calculi of approximation spaces. In this paper, we present the summarization and extension of our results obtained since 2003 when we started investigations on foundations of approximation of partially defined concepts (see, e.g., [2], [3], [7], [37], [20], [21], [5], [42], [39], [38], [40]). We discuss some important issues for modeling granular computations aimed at inducing compound granules relevant for solving problems such as approximation of complex concepts or selecting relevant actions (plans) for reaching target goals. The problems discussed in this article are crucial for building computer systems that assist researchers in scientific discoveries in many areas such as biology. In this paper, we present foundations for modeling of granular computations inside of system that is based on granules called approximation spaces. Our approach is based on the rough set approach introduced by Pawlak [24], [25]. Approximation spaces are fundamental granules used in searching for relevant complex granules called as data models, e.g., approximations of complex concepts, functions or relations. In particular, we discuss some issues that are related to generalizations of the approximation space introduced in [33], [34]. We present examples of rough set-based strategies for the extension of approximation spaces from samples of objects onto a whole universe of objects. This makes it possible to present foundations for inducing data models such as approximations of concepts or classifications analogous to the approaches for inducing different types of classifiers known in machine learning and data mining. Searching for relevant approximation spaces and data models are formulated as complex optimization problems. The proposed interactive, granular computing systems should be equipped with efficient heuristics that support searching for (semi-)optimal granules.     

On vibrations of thin plates with one-dimensional periodic structure

A new approach to problems of thin plates with a periodic structure along one direction in the planes parallel to the plate midplane is proposed. The model is a certain generalisation of the length-scale models for periodic plates, which make it possible to take into account the effect of periodicity cell size on the dynamics of plates with two-dimensional periodic structure [J. J drysiak, C. Woźniak, J. Theoret. Appl. Mech. 33 (1995) 337–349; J. J drysiak, Eng. Trans. 46 (1998) 73–87]. In order to describe this effect in stationary processes, e.g., a plate stability, and non-stationary processes for one-dimensional periodic plates the generalised model is presented in this paper. In order to show differences between governing equations of the extended model and the model for plates with two-dimensional periodic structure or the homogenised model vibrations problems of one-dimensional periodic plates will be analysed.     

Clinical neurochemistry: developments in dementia research based on brain bank material

Brain tissue obtained at autopsy continues to provide unique opportunities in current dementia research. Not only is tissue analysis still essential for diagnosis, but investigation of neurochemical pathology, at a level of resolution beyond current in vivo imaging, continues to provide new insights into the involvement of neurotransmitter signalling systems. These are relevant to therapy which, with respect to symptoms such as cognitive impairment, psychosis and depression, is currently targeted to specific transmitter (cholinergic, dopaminergic and serotonergic) systems. This paper focuses on dopaminergic, cholinergic and histaminergic parameters in Alzheimer's disease (AD), Dementia with Lewy bodies (DLB) and Parkinson's disease (PD). In the normal striatum the dopamine transporter and D2 receptor exhibit distinct rostral-caudal distributions and D2 binding is affected by genetic polymorphism at the Taq 1A locus. The transporter is reduced in both DLB and PD but not AD, correlating with severity of extrapyramidal dysfunction, and receptor abnormalities are apparent in DLB patients responding adversely to neuroleptics. Striatal nicotine receptors are lost in all 3 disorders, further reduced as a result of neuroleptic medication, and elevated as a result of tobacco use. In the thalamus there are selective reductions in presynaptic cholinergic activity in DLB in the reticular nucleus which relate to symptoms of hallucinations and fluctuating consciousness prevalent in this disorder. In the hippocampus coupling of muscarinic M1 receptors, relevant to response to cholinergic therapy, is impaired in areas most affected by beta-amyloid plaques and intact in less affected areas. Analysis of histamine H2 receptors indicates that, despite presynaptic histamine abnormalities in AD, receptor numbers are normal. Such clinically and therapeutically relevant observations on human brain neurochemistry provide a basis for improving therapeutic strategies and prospects of diagnostic in vivo chemical imaging.     

An understanding of ohmic contact formation with Ge doping of n-GaAs

Ge is commonly used as an n⁺ dopant in fabricating ohmic contacts to n-type GaAs. It is suggested here that the donor-like behaviour of this otherwise amphoteric impurity may be related to the effect of distortion of the GaAs lattice on Ge impurities. Attempts to maximise the Ge n⁺ doping behaviour, however, may enhance lattice strain and degrade device life-time.     

Corrosion resistance of model ultrafine-grained Al–Li alloys produced by severe plastic deformation

The influence of grain boundaries and fine precipitation on the corrosion behavior was investigated in two model aluminum–lithium alloys, namely (in wt%) Al–1.6Li (lithium in a solid solution) and Al–2.3Li (lithium in the form of Al₃Li precipitation), subjected to three different severe plastic deformation (SPD) treatments which refined the microstructure of the alloys to the ultrafine grain size. The SPD techniques used in the experiments were equal channel angular pressing (ECAP), hydrostatic extrusion (HE), and extrusion-torsion (ET). The corrosion behavior was examined using a potentiodynamic polarization test, electrochemical impedance spectroscopy, and an immersion test followed by a SEM surface analysis. The electrochemical tests were conducted in a 0.1 M Na₂SO₄ solution added with 100 ppm of Cl⁻. The immersion tests (48 h) were performed in a 3.5% NaCl solution at room temperature. The results indicate that the pitting potential, pit number, and stability of the passive layer formed on the surface of the substrates undergo changes depending on the average grain size and the presence of precipitation or its lack. The corrosion resistance, examined in the solution mentioned above, appears to increase with decreasing average grain size. The ET method gave the microstructure with the lowest corrosion resistance.