Quantification of Dendritic Spines Remodeling under Physiological Stimuli and in Pathological Conditions

Numerous brain diseases are associated with abnormalities in morphology and density of dendritic spines, small membranous protrusions whose structural geometry correlates with the strength of synaptic connections. Thus, the quantitative analysis of dendritic spines remodeling in microscopic images is one of the key elements towards understanding mechanisms of structural neuronal plasticity and bases of brain pathology. In the following article, we review experimental approaches designed to assess quantitative features of dendritic spines under physiological stimuli and in pathological conditions. We compare various methodological pipelines of biological models, sample preparation, data analysis, image acquisition, sample size, and statistical analysis. The methodology and results of relevant experiments are systematically summarized in a tabular form. In particular, we focus on quantitative data regarding the number of animals, cells, dendritic spines, types of studied parameters, size of observed changes, and their statistical significance.     

Vortices and vortical structures in internal aerodynamics

The paper aims at summarizing the author‘s recent phenomenological study of the origin,development and identification of vortical structures in internal aerodynamics.A connection between evolution of these structures and flow separation in closed curved channels is also discussed.It has been shown that in real fluids the individual vortex cores very sonn lose their identity and merge into a new dissipative structure,the properties of which still have to be defined.     

Possible impacts of floods and droughts on water quality

The gradual climate change symptoms in many places on Earth have been observed during the last 20 years. There is a significant increase in frequency and extremity of meteorological and hydrological events (EEA, 2007) that lead to distinct excess or lack of water in landscape. These phenomena affect not only actual quantity of water but also its quality with direct and indirect impacts on aquatic organisms. From the environmental impact point of view, drought events are considered to be more dangerous due to their medium-term to long-term characteristics and large spatial impacts. However, this study presents that the particular flood event had significantly greater impact on water quality than the period of drought even if for only a very short time The paper reviews changes in water quality with all its consequences during selected extreme hydrological situations in the Czech Republic in last 10 years and compares them with the knowledge of impacts of floods and droughts on water quality collected from literature.     

Comparison of HPLC and GLC methodologies for determination of glucosinolates using reference material

 The reference material rapeseed of known glucosinolate composition, was analysed by HPLC and GLC and two commercially available glucosinolates (glucotropaeolin and sinigrin) were used as internal standards. The HPLC method enabled determination of 11 different glucosinolates (as desulphoglucosinolates) that occur in the rapeseed. Only seven glucosinolates (as trimethylsilylated desulphoglucosinolates) were separated by GLC. The latter method did not allow the determination of methylsulphinylalkyl glucosinolates (glucoiberin, glucoraphanin and glucoallysin) and did not separate optical isomers of 2-hydroxy-3-butenyl glucosinolate (progoitrin and epi-progoitrin). Statistical evaluation of data (t-test, F-test) revealed no significant differences between the tested methods at the 95% confidence level. The advantages and disadvantages of both widely used chromatographic methods are discussed. Received: 26 May 1997 / Revised version: 11 July 1997     

Heat Transfer in Industrial Applications—PRES 2008

This editorial provides an overview of a special issue dedicated to the 11th Conference on Process Integration, Modeling, and Optimization for Energy Saving and Pollution Reduction—PRES 2008. Nine papers have been selected and peer-reviewed covering important subjects of heat transfer engineering. They focus on recent development of various features of heat transfer equipment design and optimization. This issue of Heat Transfer Engineering is the sixth special journal issue dedicated to selected papers from PRES conferences [1 Kleme?, J. and Stehlik, P. 2002. PRES Conference—Challenges in Complex Process Heat Transfer. Heat Transfer Engineering, vol. 23: 1–2.  [Google Scholar], 2 Stehlík, P. and Kleme?, J. 2004. Selected Papers from the PRES 2002 Conference. Heat Transfer Engineering, vol. 25: 1–3.  [Google Scholar], 3 Kleme?, J. and Stehlík, P. 2005. Selected Papers from the PRES 2003 Conference. Heat Transfer Engineering, vol. 26: 1–3.  [Google Scholar], 4 Stehlík, P. and Kleme?, J. 2006. Recent Advances on Heat Transfer Equipment Design and Optimization—Selected Papers from PRES 2004 Conference. Heat Transfer Engineering, vol. 27: 1–3.  [Google Scholar], 5 Stehlík, P. and Kleme?, J. 2008. Achievements in Applied Heat Transfer—PRES 2006. Heat Transfer Engineering, vol. 29: 503–505.  [Google Scholar]].     

DMA thermal analysis of different parts of potato tuber

Dynamic mechanical analysis (DMA) was applied to three potato tissues (‘cortex’, ‘pith’, and ‘side’ surface) of two cultivars (more waxy ‘Nicola’ and more mealy ‘Saturna’) in temperature scans in the range 30–90 °C and constant air humidity of 90%. The obtained scans indicate peaks in both storage and loss module of elasticity (SM and LM, respectively) at temperatures higher than 70 °C – so called ‘starch’ peak (SP) – as was observed previously. The peak value increase with increasing potato dry matter (DM) content, below DM content approximately 14% no SP is observed (‘Nicola pith’). Slope analysis of the basic parameters: SM, LM, and loss tangent (LT) was performed and further characteristic points on the temperature plots were found: (i) in temperature range A (30–40 °C) maximum of SM and LM and minimum of LT, (ii) in temperature range B (40–50 °C) minimum of SM and LM slopes corresponding to point of inflection on SM-T and LM-T plots, (iii) at about 50 °C, big peak in LT in side tissue only, (iv) at about 70 °C just prior the ‘starch’ peak, big peak in LT that is more marked in ‘pith’; this peak denoted as ‘I’ influenced the ‘starch’ peak ‘II’. It was found that both cultivar and part of the tuber influences the DMA temperature plots.     

Iron reduction potentiates hydroxyl radical formation only in flavonols

Flavonoids, substantial components of the human diet, are generally considered to be beneficial. However, they may possess possible pro-oxidative effects, which could be based on their reducing potential. The aims of this study were to evaluate the ability of 26 flavonoids to reduce ferric ions at relevant pH conditions and to find a possible relationship with potentiation of hydroxyl radical production. A substantial ferric ions reduction was achieved under acidic conditions, particularly by flavonols and flavanols with the catecholic ring B. Apparently corresponding bell-shaped curves displaying the pro-oxidant effect of flavonols quercetin and kaempferol on iron-based Fenton reaction were documented. Several flavonoids were efficient antioxidants at very low concentrations but rather inefficient or pro-oxidative at higher concentrations. Flavonols, morin and rutin were progressively pro-oxidant, while 7-hydroxyflavone and hesperetin were the only flavonoids with dose-dependent inhibition of hydroxyl radical production. Conclusively, administration of flavonoids may lead to unpredictable consequences with few exceptions.     

Naming and identification of tastes in aqueous solutions.

Several taste substances were tested in aqueous solutions; tannic and tartaric acids were found unsuitable as a standard substance for the taste identification. Monosodium glutamate, sodium hydrogen carbonate and potassium chloride were often identified as salty substances even when the subjects were able to distinguish between the tastes. They probably identified the taste as salty owing to the lack of proper terms, and unsufficient experience with tasting monosodium glutamate and sodium hydrogen carbonate as substances possessing defined tastes different from the salty taste.     

The potentiometric behaviour of copolymers of methacrylic acid in water-ethanol solutions

Summary The synthesis is reported of copolymers of styrene with methacrylic acid and of methyl methacrylate with methacrylic acid by radical copolymerization, of copolymers of methyl methacrylate with methacrylic acid by partial alkaline hydrolysis of poly(methyl methacrylate), and of block copolymers of styrene with methacrylic acid. Modified titration curves of all these copolymers were recorded in water and water-ethanol solutions. In a solution containing 50 mass.% ethanol, only small differences could be observed between the potentiometric behaviour of the individual copolymers and polymethacrylic acid. Also, there were no essential differences in any of the solvents used between the potentiometric behaviour of block copolymers of styrene with methacrylic acid, on the one hand, and polymethacrylic acid, on the other. On the contrary, maxima and minima were always observed on the modified titration curves of statistical copolymers with a higher content of the hydrophobic comonomer in solutions with a high water content. Thus, using the modified titration curves, it is possible to decide whether a given copolymer is of the block or statistical type.     

Impacts of Climate Variables on Residential Water Consumption in the Czech Republic

The paper investigates whether there is a statistically significant impact of short-term climate variables (specifically air temperature and rainfall) on residential water consumption at two selected case sites in the Czech Republic. The analysis is based on a unique time series of daily data from 2004–2009. The statistical methods used are CART methodology and a decomposition of these time series based on a locally weighted regression method. Apart from the data analysis results, the investigation raises several methodological questions regarding the use of daily data and the scope of analysis based on such data sets.