Direct Volume Rendering Methods for Cell Structures

The study of the complicated architecture of cell space structures is an important problem in biology and medical research. Optical cuts of cells produced by confocal microscopes enable two‐dimensional (2D) and three‐dimensional (3D) reconstructions of observed cells. This paper discuses new possibilities for direct volume rendering of these data. We often encounter 16 or more bit images in confocal microscopy of cells. Most of the information contained in these images is unsubstantial for the human vision. Therefore, it is necessary to use mathematical algorithms for visualization of such images. Present software tools as OpenGL or DirectX run quickly in graphic station with special graphic cards, run very unsatisfactory on PC without these cards and outputs are usually poor for real data. These tools are black boxes for a common user and make it impossible to correct and improve them. With the method proposed, more parameters of the environment can be set, making it possible to apply 3D filters to set the output image sharpness in relation to the noise. The quality of the output is incomparable to the earlier described methods and is worth increasing the computing time. We would like to offer mathematical methods of 3D scalar data visualization describing new algorithms that run on standard PCs very well. SCANNING 34: 367‐377, 2012. © 2012 Wiley Periodicals, Inc.     

The development of a method to measure speed adaptation to traffic complexity: identifying novice, unsafe, and overconfident drivers

To monitor novice driver performance in the first years of solo driving, a test aimed at assessing speed adaptation to the traffic situation was developed and evaluated. The Adaptation Test consisted of 18 traffic scenes presented in two (almost) identical photographs, which differed in one single detail, increasing the situation's complexity. As the pictures were presented randomly and participants could not return to previous pictures, participants were kept unaware of the complexity differences in the pictures. The difference in reported speed between the two pictures was used as an indication of drivers' inclination to adapt their speed to the complexity of the traffic situation. Results showed that novice drivers (n=434) performed worse on the Adaptation Test (i.e. less often reported a lower speed in the more complex situation) than experienced drivers (n=173). In addition, unsafe drivers and overconfident drivers, as identified in an on-road driving assessment, performed worse on the Adaptation Test. This indicates that the Adaptation Test is effective at measuring adaptation of driving speed to the complexity of the situation; and that incorrect self-assessment, and overestimating driving skills in particular, may have a negative effect on speed adaptation.     

Quantitative determination of fluorine in spent grain and brewery yeast

Previously published studies have shown that fluorine could present a health risk for humans. In this context, legislative regulations define the fluorine limits in many commodities, including brewery by‐products, such as spent grain and brewery yeast used as a feed. A method for the determination of fluorine in these by‐products using gas chromatography with flame ionization detection is therefore proposed. The first step is based on extraction of fluorine with 1 mol/L hydrochloric acid solution simulating acidic stomach surroundings. Then, fluorine is derivatized by trimethylchlorosilane to form trimethylfluorosilane (TMFS), which is subsequently extracted in liquid–liquid mode. TMFS is then analysed by gas chromatography–flame ionization detection; n‐pentane is used as an internal standard for fluorine quantification. The recovery of the method was >96%. The results also showed a high correlation coefficient (R > 0.999) in the calibration range studied (0–2000 mg/kg). The precision of the method, expressed as the relative standard deviation, was 13%. The limit of quantification was 0.02 mg/kg. This method was used for pilot screening of fluorine in 16 grain and 12 yeast samples. The resulting concentrations of fluorine ranged between 1.5 and 20.0 mg/kg, levels far below the legislative limits. Copyright © 2015 The Institute of Brewing & Distilling     

Occurrence of enterotoxic Staphylococcus aureus in raw milk from yaks and cattle in Mongolia

Staphylococcal food poisoning is considered one of the leading foodborne illnesses in humans worldwide and is associated with contaminated foods of animal origin, such as milk and dairy products. In this study, we investigated the occurrence of staphylococci and the enterotoxigenic properties of Staphylococcus aureus isolated from raw milk from yaks (Bos mutus) and cattle in Mongolia. Staphylococci were isolated from 72 (74%) of the 97 raw milk samples. Of the samples containing staphylococci, 69% (50 of 72) were from yaks and 30.5% (22 of 72) were from cattle. S. aureus was detected in 10% of yak (7 of 72) and 21% of cattle (15 of 72) milk samples. Staphylococcal enterotoxin C was detected in 23% (5 of 22) of the S. aureus strains investigated, based on the reverse passive latex agglutination technique. Three of the five enterotoxigenic strains were from yaks and two were from cattle. None of the S. aureus strains tested produced staphylococcal enterotoxins A, B, or D. To our knowledge, this is the first report of the occurrence of staphylococci and enterotoxigenic S. aureus in milk from yaks and cattle in Mongolia.     

Applying state diagrams to food processing and development

The physical state of food components affects their properties during processing, storage, and consumption. Removal of water by evaporation or by freezing often results in formation of an amorphous state (Parks et al., 1928; Troy and Sharp, 1930; Kauzmann, 1948; Bushill et al., 1965; White and Cakebread, 1966; Slade and Levine, 1991). Amorphous foods are also produced from carbohydrate melts by rapid cooling after extrusion or in the manufacturing of hard sugar candies and coatings (Herrington and Branfield, 1984). Formation of the amorphous state and its relation to equilibrium conditions are shown in Fig. 1 [see text]. The most important change, characteristic of the amorphous state, is noticed at the glass transition temperature (Tg), which involves transition from a solid "glassy" to a liquid-like "rubbery" state. The main consequence of glass transition is an increase of molecular mobility and free volume above Tg, which may result in physical and physico-chemical deteriorative changes (White and Cakebread, 1966; Slade and Levine, 1991). We have conducted studies on phase transitions of amorphous food materials and related Tg to composition, viscosity, stickiness, collapse, recrystallization, and ice formation. We have also proposed that some diffusion-limited deteriorative reactions are controlled by the physical state in the vicinity of Tg (Roos and Karel, 1990, 1991a, b, c). The results are summarized in this article, with state diagrams based on experimental and calculated data to characterize the relevant water content, temperature, and time-dependent phenomena of amorphous food components.     

Capillary isoelectric focusing and fluorometric detection of proteins and microorganisms dynamically modified by poly(ethylene glycol) pyrenebutanoate

The nonionogenic pyrene-based tenside, poly(ethylene glycol) pyrenebutanoate, was prepared and applied in capillary isoelectric focusing with fluorometric detection. This dye was used here as a buffer additive in capillary isoelectric focusing for a dynamic modification of the sample of proteins and microorganisms. The values of the isoelectric points of the labeled bioanalytes were calculated with use of the fluorescent pI markers and were found comparable with pI of the native compounds. The mixed cultures of proteins and microorganisms, Escherichia coli CCM 3954, Staphylococcus epidermidis CCM 4418, Proteus vulgaris, Enterococcus faecalis CCM 4224, and Stenotrophomonas maltophilia, the strains of the yeast cells, Candida albicans CCM 8180, Candida krusei, Candida parapsilosis, Candida glabrata, Candida tropicalis, and Saccharomyces cerevisiae were reproducibly focused and separated by the suggested technique. Using UV excitation for the on-column fluorometric detection, the minimum detectable amount was down to 10 cells injected on the separation capillary.     

Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.     

A New,Thorough Look on Unusual and Neglected Group III-VI Compounds Toward Novel Perusals

The attention on group III-VI compounds in the last decades has been centered on the optoelectronic properties of indium and gallium chalcogenides. These outstanding properties are leading to novel advancements in terms of fundamental and applied science. One of the advantages of these compounds is to present laminated structures, which can be exfoliated down to monolayers. Despite the large knowledge gathered toward indium and gallium chalcogenides, the family of the group III-VI compounds embraces several other noncommon compounds formed by the other group III elements. These compounds present various crystal lattices, among which a great deal is offered from layered structures. Studies on aluminium chalcogenides show interesting potential as anodes in batteries and as semiconductors. Thallium (Tl), which is commonly present in the +1 oxidation state, is one of the key components in ternary chalcogenides. However, binary Tl–Q (Q = S, Se, Te) systems and derived films are still studied for their semiconducting and thermoelectric properties. This review aims to summarize the biggest features of these unusual materials and to shed some new light on them with the perspective that in the future, novel studies can revive these compounds in order to give rise to a new generation of technology.     

Photoluminescence of rare-earth/transition metal-doped transparent/translucent polycrystalline Al2O3 ceramics: A review

Transparent alumina doped with rare-earth or transition metal oxides represents a group of materials suitable for optical applications. Because of the birefringence of alumina, their preparation is demanding on the quality of starting materials, their advanced shaping, and pressure-assisted sintering. Spark plasma sintering and hot isostatic pressing have proven at achieving pore-free fine microstructures exhibiting high in-line transmission and a sufficient intensity of emitted light. The present review aims to summarize the results published on this topic, to compare them and on this base to propose other possible and/or appropriate approaches to future.     

Magneto-hydrodynamic mixing: A new technique for preparing carbomer hydrogels

Magnetohydrodynamic mixing was evaluated as an alternative to conventional high shear mixing (HSM) in the preparation of carbomer hydrogels containing 1.22 wt% Carbopol® 980 NF. Neutralization of the carbomer dispersion (pH = 2.74) with triethanolamine (TEA) enabled to adjust the pH of the mixture and tune the viscosity of the hydrogel. Using HSM, this approach was limited to 0.2 wt% TEA (pH = 3.83) as the gel became too viscous and the recirculation flow dropped from 12 to 0.3 m³/h. Magnetohydrodynamic mixing enabled to reach TEA concentrations up to 1.0 wt% (pH = 5.31). Apparent viscosity measurements on samples having 0.2 wt% TEA revealed lower viscosities for carbomer hydrogels prepared with HSM, that is, 6800 mPa s versus 8800 mPa for magneto-hydrodynamic mixing. Based on ¹H NMR evidence, this decrease in apparent viscosity was attributed to structural damage to the carbomer backbone in combination with mechanochemical degradation of the added TEA.