Fulltext search in archive

A simple 1-D mathematical model for prediction of local temperatures in a layer of solid material during microwave heating (Houšová et al. 1998) and a sensitivity analysis were used to evaluate the influence of process and material parameters on vertical temperature profiles in a layer of material during heating. The results of calculations are presented in graphs and discussed. The incident microwave power and heat capacity and density of heated material are parameters with great effect on all local and average temperatures and local and average heating rates. The shape of temperature profile is influenced only to a small extent by a change in the value of applied microwave power and also in the value of heat capacity or density of heated material. The whole profiles shift to higher or lower temperature values when the incident microwave power is changing. The distribution of applied microwave power between the upper and bottom layer surface very much influences the shape of the profile and the values and position of the highest and the lowest temperature in the layer. Depth of penetration and thermal conductivity of heated material influence on the shape of temperature profiles and the temperature spread in the layer (evenness of temperature distribution). Effect of penetration depth also depends on the relation to the layer thickness - its effect increases with the increasing layer thickness. At the low values of penetration depth relative to the layer thickness, an uneven temperature profile is to be expected. Effect of thermal conductivity value on temperature profile depends on the time of heating. Because of a short time of microwave heating, the effect of this parameter on temperature distribution is smaller compared to the conventional heating methods. At the beginning of heating its influence is quite negligible. Temperature of the air surrounding the layer and intensity of heat exchange between the air and layer surface are parameters with only small local effect on temperature distribution.

The objective of this work was the morphologic analysis of apoptosis of neutrophilic granulocytes (hereinafter referred to as neutrophils) in scanning electron microscopy (SEM) in comparison with morphological features distinguishable by light microscopy. This study was performed on 12 bovine virgin mammary glands washed with physiological buffered solution (PBS) prior to the induction of cell influx by PBS. Twenty-four hours after influx induction the cell suspension was obtained by the lavage of mammary glands with PBS. The particular lavages were cytologicaly and bacteriologicaly examined. all bacteriological examinations were negative. Mononuclear phagocytes (MoP), lymphocytes and neutrophils were distinguished in the cell suspension of the lavages by means of light microscopy. The neutrophils predominated in differential cell count. Neutrophil population showed some signs of structural features typical for the process of apoptosis that were distinguished in haemocytometer and light microscopy on stained microscopical smears. The process of apoptosis consisted of three structurally different stages: karyopyknosis, zeiosis and the stage of apoptotic bodies. These stages of neutrophil apoptosis were distinguished also by SEM. Karyopyknotic neutrophils assumed spherical shape while they lost all of their superficial pseudopodia. Neutrophils in zeiosis stage showed prominent surface protumberances, bubble-shaped vesicles causing a bizarre deformation of the cells. After the membrane vesicles had split off, they began to form spherical formations (apoptotic bodies). On the basis of neutrophils. specific structural properties it could easily distinguish all the three stages of neutrophil apoptosis by means of SEM technique as well as other morphological methods.

The astringent taste is important for the sensory quality of beverages. Perception thresholds of two important astringent compounds - tannic acid and (+)-catechin were determined using two procedures. The concentration-intensity dependence was linear at low concentrations and up to medium intensities of the astringent taste if unstructured graphical scales were used, but the saturation threshold was soon attained in the case of tannic acid. Recording the results on printed forms gave similar results as using a touch-sensitive monitor. The optimum tasting was achieved at swallowing after degustation of 5 s. The duration of degustation increased the intensity. The astringent flavour was suppressed by sugar, but was not significantly influenced by ethanol, citric acid or quinine hydrochloride. Astringent substances were accurately perceived and rated in wine, tea infusion and orange drink, but the increase of astringency was smaller than in model solutions. The astringent taste was easily distinguished from the bitter taste.

Ten autoaggregating vaginal Lactobacillus strains (five of these strains were selected among isolates from sows' vaginal swabs and the other five among isolates from cows' vaginal swabs) were investigated for their ability to bind type Icollagen (Cn-I). All 10 autoaggregating strains in the range of A_570nm readings 0.118-1.806 bound to immobilised Cn-I (at concentration of 100 μg/ml) in wells of microtitre plates, however, Lactobacillus acidophilus SV31 was much more adherent than the rest of the tested strains. The influence of culture medium on Cn-I binding was confirmed only in 50% of the tested strains when agar-grown cells bound significantly more Cn-I than broth-grown cells. The specificity of the binding was confirmed since the Cn-I binding by lactobacilli was abolished after their preincubation with this protein. The effect of heparan sulphate and hyaluronic acid was tested on 5 vaginal strains displaying the best Cn-I binding in microtitre plates after their cultivationon MRS agar plates. Both selected inhibitors significantly (P < 0.001 or P < 0.01) reduced Cn-I binding by the majority of strains. The presence of the gene coding APF (aggregation-promoting factor) was detected in seven strains (all five sows' and two cows' Lactobacillus strains) by PCR.

The changes in microbiological and chemical parameters during the fermentation and ripening of sheep cheese were observed. The cheese was produced from raw sheep's milk at different temperatures on the sheep farm. The following parameters were determined: total plate count, coliform count, Staphylococcus aureus count, pH value, titrimetric acidity, and the amount of lactic acid. As our results indicate, the fermentation at temperatures of between 18-22°C reduces the number of undesirable micro-organisms due to the presence of lactic acid being produced by lactic-acid bacteria. During the fermentation at lower temperatures (below 18°C) the amount of lactic acid is insufficient, and the undesirable microorganisms can survive.

More than 4 000 E. coli strains isolated from diarrhoeic piglets in 111 pig herds in the Czech Republic during the period 1995-2000 were examined for serogroup and virulence factors. Gene typing of the K88 marker by polymerase chain reaction (PCR) was used for the examination of 283 enterotoxigenic strains (ETEC) which agglutinated with antisera against K88 or adhered to intestinal brush borders. The K88 gene was detected in 237 strains; among them 232 strains possesed the K88 variant. Genotype K88ab was found in two strains of the serogroup O8 from one herd and the gene K88ad was detected in three strains of the serogroup O8 originating from another herd. The results show that the type K88ac is predominant in ETEC strains with colonisation factors K88 in pig herds in the Czech Republic.

Distribution of leukocyte types present in virgin bovine mammary glands was analysed in dot plots obtained by flow cytometry (FACS) of samples collected from 10 non-pregnant heifers after induction of leukocyte influx. Changes of percentage of leukocyte types during development and resolution of induced influx in comparison with blood leukocyte pattern allow identification of these cell types on FACS dot plot. The positions of mammary gland granulocyte and lymphocyte regions were identical with those of the corresponding peripheral blood cells. Two basic morphologically distinct types occupying separate regions in dot plots were observed in the population of mononuclear phagocytes (MoP): non-vacuolised monocyte-like macrophages (MoMAC) and vacuolised macrophages (MAC). Influx resolution was characterised by a marked shift of the MoMAC region towards that of MAC recognisable in dot plots by a separate region of intermediate MoP forms. The study provides a pattern of dynamics of percentages of mammary gland leukocyte types during influx development and resolution as imaged by FACS.

Phenolic compounds were extracted from rye caryopses with 80% (v/v) methanol. Phenolic acids were determined as free compounds and those liberated from soluble esters and glycosides. The analyses were performed using a Waters HPLC system equipped with a diode array detector (DAD). The following free phenolic acids were found: p-coumaric, ferulic and sinapic; the phenolic acids liberated from soluble esters were as follows: vanillic, caffeic, p-coumaric, ferulic and sinapic; and those liberated from soluble glycosides were the following: vanillic, p-coumaric, ferulic and sinapic. In rye caryopses, phenolic acids were chiefly in the form of soluble esters. A diode array detector was especially useful for the determination of vanillic acid: the UV spectrum of this compound showed a maximum at 260 nm whereas UV spectra of other phenolic acids were characterised by maxima at longer wavelengths.

The aim of this paper was to register the domestic animals appearing in the iconography of Christian saints and to explain their association. The source of knowledge was literature dealing with hagiographies of saints, sacral iconography and liturgy along with visiting churches, monasteries and museums throughout Croatia. After research in sacral literature and works of art lasting several years, it was observed that the following domestic animals appear as accompanying about seventy Christian saints: bees, bull, camel, cow, dog, donkey, goose, dove, horse, lamb, pig, sheep, steer. Reasons and explanations of their association are most often in practical relations (the animal serves and helps the man). However, in the animal, the most varied symbolic, especially ethical and morality messages are personified very often. Especially interesting are saints honoured as patrons of particular animals and of professionals occupied with animals. In human medicine, they are most frequently protectors from zoonoses, too. In some cases, animals are attributed to saints because of the linguistic association resulting from similarity of the names of animals and saints. In the same way, domestic animals are present in sacral art as a part of ambient decoration, too. In addition, it can also be interesting from the historical and ethnic veterinary point of view. Presented examples show how, by interdisciplinary approach to sacral art and tradition, we can come to other numerous findings surpassing mere religious messages. In this case, these are contributions to the history of veterinary medicine in the widest sense.

Based on extensive literature review, the characteristics of a learning organisation are depicted as a starting point to define a pragmatic tool to assess the level to which an organisation meets the individual characteristics of learning organisation. The tool is designed as a matrix combining eight characteristics of learning organisation with four improvement levels including feedback loop. This tool has been tested in 9 organisations and the examples of information gathered through this exercise are provided and discussed.

In Europe in the period 1994-1998, Helminthosporium leaf blotch disease was recorded in Austria, Belarus, Bulgaria, the Czech Republic, Estonia, Finland, Hungary, Italy, Norway, Poland, Russia and Yugoslavia. There was large variation in the quantitative reaction of oat (Avena sativa L.) genotypes to this disease, ranging from a disease resistance index (DRI) of 71 with cv. Kasadra to 16 with cv. Pan. Oat genotypes such as Kasadra, Pc 60, Pc 61, IL 86-6404, IL 86-1158, Rodney M, Pg 15, Cc 4761, Vermiou, Roxton, IL 85-6467, IL 85-2069, Pc 54-2, Orlando, OM 1387, Pc 59, KR 3813/73, IL 86-4189, Pc 68, Melys, OA 503-1, KR 288/73L/569, POB 1429/93, Pg l6, Pc 55 and Pc 56 had a consistently high disease resistance index. On the other hand, some had a low index which confirms the existence of pathogenic specialization of the causal fungus Pyrenophora avenae Ito et Kurib. Despite the absence of detailed analyses of the reaction of oats to the pathogen, it seems feasible to breed for resistance to the disease.

Two resistance phenotypes to P. brassicae have been found in A. thaliana. A first resistance phenotype has been detected to the isolate 'e₂' and is polygenically inherited. The second resistance to isolate 'e₃' is caused by the dominant resistance gene RPB1. By crossing no influence could be shown for salicylic acid, jasmonic acid and ethylene in the latter resistance reaction. The RPB1 locus was narrowed down to 71 kb on chromosome 1, where three pseudogenes and 13 coding sequences are located. Six of them showed cosegregation with RPB1. None of these sequences have similarities to identified resistance genes or other known genes. Ten coding sequences were expressed, but CDS9 was exclusively expressed in the resistant ecotype Tsu-0.

Control of SVBV relies completely on the use of virus-free planting material, that can be tested either by biological indexing or by molecular methods. A NASBA-based amplification was developed for the detection of SVBV. NASBA is a method based on the primer-dependent, specific amplification of RNA by concurrent activity of a special enzyme mix (AMV-reverse transcriptase, RNaseH, T7 RNA polymerase) at a single temperature (41°C). Specific and sensitive detection of the amplified sequence can be performed in the same tube using molecular beacons. Sensitivity of SVBV-NASBA was 102 molecules of in vitro RNA detected per reaction. Results of the NASBA-based detection of SVBV in indicator strawberry plants were well comparable to the results of PCR.

Two wheat powdery mildew differential sets were tested in the seedling stage in the 2001/2002 season using 192 monoisolates. The data of genotypes carrying the same Pm gene in different genetic backgrounds were compared. Both varieties with gene Pm8 (Salzmünde14/44 and Disponent) were infected by all the isolates. Less than 10% of the isolates gave different responses on varieties with genes Pm2 and Pm3c (6 and 16, respectively). It is doubtful whether the degree of infection of genotypes carrying genes Pm1, Pm4b, Pm5, Pm6 or Pm7 can be compared, while it is completely impossible to compare the data for varieties from the old and new sets carrying genes Pm3a, Pm3b and Pm4a.