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Results 1741 to 1770 of 1934:

Evaluation of size distribution of starch granules in selected wheat varieties by the Low Angle Laser Light Scattering method

I. Capouchová, J. Petr, D. Marešová

Plant Soil Environ., 2003, 49(1):12-17 | DOI: 10.17221/4083-PSE

The distribution of the size of wheat starch granules using the method LALLS (Low Angle Laser Light Scattering), followed by the evaluation of the effect of variety, experimental site and intensity of cultivation on the vol. % of the starch A (starch granules > 10 μm) was determined. The total starch content and crude protein content in dry matter of flour T530 in selected collection of five winter wheat varieties were determined. Vol. % of the starch A in evaluated collection of wheat varieties varied between 65.31 and 72.34%. The effect of a variety on the vol. % of starch A seemed to be more marked than the effect of site and intensity of cultivation. The highest vol. % of starch A reached evaluated varieties from the quality group C, i.e. varieties unsuitable for baking utilisation (except variety Contra with high total content of starch in dry matter of flour T530, but relatively low vol. % of starch A). A low vol. % of starch A was also found in the variety Hana (very good variety for baking utilisation). Certain variety differences followed from the evaluation of distribution of starch fractions of starch granules, forming starch A. In the case of varieties Hana, Contra and Siria higher representation of fractions up to 30 μm was recorded, while starch A in the varieties Estica andVersailleswas formed in higher degree by size fractions of starch granules over 30 μm and particularly size fraction > 50 μm was greatest in these varieties of all evaluated samples. With increasing total starch content in dry matter of flour T530 the crude protein content decreased; the vol. % of starch A not always increased proportionally with increasing total starch content.

Specific productivity of selected apricot genorypes

Z. Vachůn

Hort. Sci. (Prague), 2002, 29(4):125-132 | DOI: 10.17221/4475-HORTSCI

Specific productivity and some correlations between growth and productivity were evaluated in a set of 24 apricot (Prunus armeniaca L.) genotypes in 1994-1999. Even though the planting stock came from the same nursery, was of even age and on the same rootstock, the tree size of genotypes varied from planting to a permanent site. Differences in the tree size of genotypes slightly diminished over the six-year period, likely under the influence of uniform pruning used for all trees. Nevertheless, tree size evaluated from the area of stem cross-section can be considered as a genotype disposition. It is proved by a positive, highly significant correlation (r = 0.84++) between the rank genotypes according to the area of stem cross-section in the fourth and eleventh year after planting. Confidence intervals also confirmed significance of differences in specific productivity. In total, specific productivity of twelve genotypes was significantly higher than in the control cultivar Velkopavlovická. A negative, significant moderate correlation (r = -0.40+) was calculated between tree size and specific productivity expressed as yield weight per unit area of stem cross-section. Weakly growing genotypes had higher specific productivity. The highest specific productivity was recorded in cultivars Vynoslivyj and Priusadebnyj and in LE-1321 and LE-390 hybrids. Of them, the most interesting for producers and fruit quality was Vynoslivyj with average fruit weight 47 g and harvest ripeness 11 days after Velkopavlovická.

Population dynamics of eight-toothed spruce bark beetle (Ips typographus[L.]) in the area of National Nature Reserve Praděd in 1998-2001

P. Plašil, P. Cudlín

J. For. Sci., 2005, 51(8):359-370 | DOI: 10.17221/4571-JFS

The paper deals with the study of bionomics and population dynamics of Ips typographus (L.) in the area of the Praděd National Nature Reserve (NNR). Data were collected on the basis of detected feeding marks, beetles caught in traps, and also according to the frequency of occurrence or increase in the number of standing dead trees killed by the bark beetle attack in localities where sanitation felling was not performed. Finally, evaluation of the present condition of forest stand and population dynamics of Ips typographus was carried out. The results showed that the stands currently occur in the stage of disintegration when the role of the bark beetle is irreplaceable. Based on the research findings, the management of the bark beetle was proposed that would enable to achieve so-called regulated disintegration of natural spruce forests in the area of the Praděd NNR.

Characterisation and comparison of Pasteurella multocida isolated from different species in the Czech Republic: capsular PCR typing, ribotyping and dermonecrotoxin production

Z. Jaglic, Z. Kucerova, K. Nedbalcova, I. Pavlik, P. Alexa, M. Bartos

Vet Med - Czech, 2005, 50(8):345-354 | DOI: 10.17221/5633-VETMED

The aim of this study was to characterise and compare Pasteurella multocida isolates originating from pigs (n = 43), calves (n = 31), rabbits (n = 27), and to a lesser extent from other hosts (n = 6). A total of 107 P. multocida isolates were obtained from various locations in the Czech Republic. They were analysed by capsular PCR typing and ribotyping, and tested for the production of dermonecrotoxin. Most frequently, serogroup A isolates (n = 74) were found, followed by serogroup D (n = 25) and serogroup F (n = 8) isolates. From a total of fifteen different ribotypes (1-15) generated by restriction endonuclease MspI, four ribotypes (1, 3, 4, and 7) were predominant. The prevalence of predominant ribotypes was different in isolates originating from different hosts. Ribotype 1 was characteristic for rabbit isolates, ribotype 3 was primarily found in pig isolates, and ribotype 7 dominated among calf isolates. Sixteen (mainly porcine) isolates produced dermonecrotoxin but significant correlation among ribotypes and dermonecrotoxin production was not observed.

In sacco NDF degradability and mineral release from selected forages in the rumen

Z. Čerešňáková, P. Fľak, M. Poláčiková, M. Chrenková

Czech J. Anim. Sci., 2005, 50(7):320-328 | DOI: 10.17221/4173-CJAS

An in sacco technique was used to measure NDF degradability and release of Mg, Ca, Zn, Cu, Fe from six forages - lucerne hay from the 1st cut (LH1), from the 2nd cut (LH2), orchard grass (G), grass silage (GS), red clover silage treated with Feedtech (CSFT) and/or with Kofasil (CSKO). The forages differed in the content of NDF and minerals. There were large differences (P < 0.01) in element release in the rumen between experimental forages and the particular elements. The rate of release of elements was higher from LH1, LH2, CSFT,CSKO than from G and GS. The release of individual elements and NDF over all incubation times is very well expressed by cubic polynomials (R2> 0.9). Overall, across forages the release of mineral elements ranked as follows: Mg > Fe > Cu > Ca > Zn. The minimum and maximum disappeared portions of individual minerals from forages are as follows: Mg 74.7% from G and > 91.5% from LH1, Fe 29.7% from G and 99.9% from LH1 and LH2, Cu 64.3% from G and 99.8% from LH1 and LH2, Ca 28.4% from G and 75.4% from CSFT, Zn 12.0% from G and 38.2% from LH1, respectively. Calcium and zinc need a longer time for their maximum release. It can be concluded from the results of multiple regression analyses that only the Mg and Ca release is associated depending on NDF and time of observations, with a highly significant influence of forage on Zn and Cu.

The effect of stress factors on birch Betula pendula Roth

D. Kaňová, E. Kula

J. For. Sci., 2004, 50(9):399-404 | DOI: 10.17221/4636-JFS

In a controlled pot trial, plants of birch (Betula pendula Roth) were treated in six variants: acid watering (pH 3), acid watering with spraying, drought, ammonium sulphate fertilisation, ammonium sulphate fertilisation in combination with drought, and control. The response to the treatment with ammonium sulphate in terms of the increment was discordant as it increased the sensitivity of birch to frost. Drought had a negative effect on increments. A combination of ammonium sulphate and drought; drought; ammonium sulphate and sprayed acid watering delayed the shedding of leaves; this was due to a longer vegetation period, significantly higher nitrogen content in these variants, with the exception of drought.

Species diversity, abundance and dominance of macromycetes in beech forest stands

I. Mihál, K. Bučinová

J. For. Sci., 2005, 51(5):187-194 | DOI: 10.17221/4558-JFS

The aim of this paper is to contribute to the knowledge of dynamics of species diversity, abundance, distribution of fruiting bodies and dominance of macromycetes in mycocoenosis of beech monocultures. The problems were studied in beech monocultures on three permanent research plots with various impacts of air pollutants generated by the aluminium plant in Žiar nad Hronom. Over the research period we determined 121 macromycete species and one species of imperfect fungus. We found relatively balanced values of abundance, fruiting body distribution and species dominance on all the examined plots. The species diversity in groups consisting of the most dominant species was practically the same on each plot. As for the ecotrophic requirements of individual macromycetes, we can conclude that the diversity of tree parasites decreased with decreasing pollutant load. We also found out relatively balanced numbers of lignicolous saprophytes and terrestrial saprophytes on each research plot. Air pollutants also influenced the species spectrum of ectomycorrhizal macromycetes negatively (only 6 species on the plot with highest pollution stress and 21 species on the plot with lowest pollution stress).

Effect of zinc application on quality traits of barley in semi arid zones of Turkey

G. Kinaci, E. Kinaci

Plant Soil Environ., 2005, 51(7):328-334 | DOI: 10.17221/3594-PSE

Field experiments were carried out to study effects of zinc application on quality traits of barley in 1994-1996. The treatments were applied as 0 and 23 kg/ha of zinc sulphate and incorporated into soil before sowing. The experimental design was split plot with four replications. Barley genotypes responded differently to zinc application in relation to thousand grains weight, protein content and starch content. A significant increase was determined for thousand grain weight in cultivars Tokak 157/37 and Cumhuriyet 50, for protein content in Orza, Bülbül 89 and Anadolu 86, for starch content in Karatay 94 and Cumhuriyet 50, while a significant decrease has been found for thousand grain weight in Karatay 94 and Obruk 86 and for protein content in Karatay 94, Cumhuriyet 50 and Tarm 92. When feeding and malting quality are considered together, Karatay 94 and Cumhuriyet 50 are the most suitable cultivars for growing in zinc-applied soils of semi arid areas.

Spontaneous rupture of uterus in the bitch at parturition with evisceration of puppy intestine - a case report

J. Hajurka, V. Macak, V. Hura, L. Stavova, R. Hajurka

Vet Med - Czech, 2005, 50(2):85-88 | DOI: 10.17221/5600-VETMED

A rupture of one uterine horn at the region of small curvature and placentation was observed in a pregnant 8-year old Schnauzer bitch carrying a single foetus. It occurred at its second parturition. The first whelping at the age of 3 years had been without complications and the bitch reared eleven puppies. The uterine rupture occurred at the puppy's umbilical cord. An urgent obstetrical examination revealed one dead foetus in anterior presentation and ventral position. Caesarean delivery was indicated. Evisceration of puppy's intestine through its ruptured abdominal wall at the umbilical cord could be observed through the uterine wall rupture of 1.5 cm in diameter. The bitch underwent hysterectomy and recovered without complications.

Analysis of cambial activity and formation of wood in Quercus robur L. under conditions of a floodplain forest

P. Horáček, J. Šlezingerová, L. Gandelová

J. For. Sci., 2003, 49(9):412-418 | DOI: 10.17221/4714-JFS

The analyses of the activity of cambium and the study of the increment of wood during one growing season of pedunculate oak (Quercus robur L.) under conditions of a floodplain forest is provided. The following parameters were studied: the beginning and end of the cambial activity, differentiation of wood fibres (libriform) and vessels and analysis of the total increment of wood during vegetation in dominant (D), co-dominant (CD) and subdominant (SD) trees in relation to ecological factors of the environment. The course of wood formation corresponds to typical growth curves which are modified by factors of the environment (mean daily temperature, precipitation, soil water supply). The rate of growth is limited by factors of the environment and under the lack of some of them it is reduced resulting in the decrease in the total production of cells. Oak is a species sensitively responding to the period of drought which is particularly manifested in wood increment in subdominant trees. Sufficient supplies of water during spring months accelerate the formation of early wood including differentiation of spring vessels as corroborated by the results. The total formation of wood is dependent not only on the characteristics of the respective growing season but particularly on the social position of trees in the stand.

Structure, quality, production, LAI and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) stand

F. Tokár, E. Krekulová

J. For. Sci., 2005, 51(2):67-76 | DOI: 10.17221/4545-JFS

The paper evaluates the growth, structure, production, quality, leaf area index and dendrochronology of 100 years old Austrian pine (Pinus nigra ARNOLD) monoculture situated in the forest type group Fageto-Quercetum in the locality Horné Lefantovce (Nitrianska Streda Forest District, Topoľčianky Forest Enterprise). Codominant trees, trees with stem of high quality, with medium-sized crown, medium dense and straight crown are the most abundant in the stand. The tree number in the stand is 1,024 trees/ha, basal area 51.75 m2/ha, growing stock 571.56 m3/ha, aboveground biomass stock 348.76 t/ha and leaf area index 21.85 ha/ha. Dendrochronological analyses examined the response in individual sample trees and minimum annual ring width was found in 1920, 1922, 1925, 1929, 1933, 1938, 1944, 1946, 1947, 1949, 1952, 1954, 1963, 1968, 1976, 1982, 1990, 1993, 1998, 2001. Marked maximum values of annual ring width in the years 1919, 1923, 1926, 1930, 1936, 1937, 1941, 1948, 1951, 1955, 1959, 1966, 1972, 1975, 1980, 1985, 1997 were found as a positive productive feature. Beginning in the year 1993, dry Austrian pine trees occurred in the stand as a result of the fungal infection by Sphaeropsis sapinea (Fr.) Dyko et Sutton.

Comparison of humus form state in the beech and spruce parts of the Žákova hora National Nature ReserveOriginal Paper

V. V. Podrázský, J. Viewegh

J. For. Sci., 2005, 51(20):29-37 | DOI: 10.17221/11846-JFS

The paper summarises main ideas concerning the structure of natural forest ecosystems at middle altitudes and documents the changes of humus forms and their chemistry in the natural forest of Žákova hora National Nature Reserve, in typical selected parts with different tree species composition: European beech - Norway spruce. The species composition, age and spatial structure are discussed and analysis of the uppermost soil layer is done in particular parts of the natural forest regeneration cycle, of different stages respectively. We compared the amount and layer composition of surface humus and basic pedochemical characteristics of holorganic and upper mineral horizons. The results document changes in the character of humus forms as a consequence of the tree species change. On the contrary, a high portion of uncertainty as for the species, age and spatial structure follows from discussion about the structure of natural forests at middle altitudes.

Prospects of classical cross protection technique against Citrus tristeza closterovirus in Pakistan: A review

M. Abbas, M. M. Khan, S. M. Mughal, I. A. Khan

Hort. Sci. (Prague), 2005, 32(2):74-83 | DOI: 10.17221/3769-HORTSCI

In Pakistan citrus groves in general are facing a serious problem of decline that is attributed to different causes. The major cause, however, is the prevalence of citrus virus and virus-like diseases; Citrus tristeza virus (CTV) is of utmost concern. Although CTV has been identified and characterized on the basis of serological and physical properties, no information is available on the strains of CTV in Pakistan. The identification of CTV strains will be helpful in developing strategies to control the decline of citrus trees to a great extent. Many citrus growing countries have successfully used the technique of cross protection to minimize the drastic effect of severe CTV strains. By pre-immunization of the citrus tree with mild strains, the decline can be controlled to increase the life span of the citrus tree. In this study we focus on the possibility of establishing a cross protection technique in Pakistan against the CTV strains.

Influence of phytotechnology on growth, production and leaf area index of black walnut (Juglans nigra L.) monocultures in Slovakia

F. Tokár, E. Krekulová

J. For. Sci., 2005, 51(5):213-224 | DOI: 10.17221/4592-JFS

In the paper we evaluate the influence of crown thinning with positive selection, different intensity (moderate PRP III and heavy PRP IV) and 5-year frequency on development of growth, production, quality and leaf area index of black walnut (Juglans nigra L.) monocultures growing on the series of three permanent research plots (PRP) Sikenica (Levice Forest Enterprise, Levice Forest District) as observed in 1978-2003. The trends of development of mean stem, basal area, standing volume and aboveground dendromass (in dry matter) were mainly influenced by heavy crown thinning. The index of growth was as follows: basal area 169.01%, standing volume 262.12%, aboveground dendromass (in dry matter) 324.48%. At the age of 64 years the black walnut monocultures tended by heavy crown thinning had the following parameters: basal area 31.03 m2/ha, standing volume 463.88 m3/ha and aboveground dendromass 194.98 t/ha. Mean periodic increment reached the values: basal area 0.51 m2/ha/year, standing volume 11.48 m3/ha/year and dendromass 5.39 t/ha/year. The index of increment percent growth was: basal area + 31.75%, growing stock + 30.85% and dendromass + 0.79%, compared to the control. The total production was also significantly influenced by heavy thinning. At the stand age of 64 years the tended stands had the total basal area of 4.92 m2/ha, total volume production of 572.77 m3/ha and total weight production of 246.04 t/ha. The total mean increment of basal area is 0.67 m2/ha/year, of volume 8.95 m3/ha/year and of weight 3.84 t/ha/year, which is by 24.07%, 23.96% and 16.01% more than on the control plot. The leaf area index at the age of 64 years ranges from 6.54 ha/ha (PRP III) to 7.82 ha/ha (PRP V). Dendrochronological analyses revealed minimum widths of annual rings in the years 1952, 1961, 1968, 1971, 1975, 1981, 1983, 1985, 1993, 2000, maximum ones in 1951, 1957, 1959, 1967, 1974, 1979, 1982, 1984, 1989, 1999.

In vivo culture of bovine embryos and quality assessment of in vivo vs. in vitro produced embryos

V. Havlicek, M. Lopatarova, S. Cech, R. Dolezel, T. Huber, A. Pavlok, G. Brem, U. Besenfelder

Vet Med - Czech, 2005, 50(4):149-158 | DOI: 10.17221/5608-VETMED

Routine access to the bovine oviduct for in vivo culture accomplishes various demands on embryo production for scientific as well as commercial purposes. The experiments conducted in the present study focused on the efficiency of recovery methods after temporary in vivo culture of bovine embryos in oviducts of the homologous species using transvaginal endoscopy (Experiment I) and on the quality assessment of recovered blastocysts (Experiment II). In Experiment I in vitro matured oocytes were fertilized, cultured for 1 to 3 days and transferred unilaterally into the ipsilateral oviducts of 54 heifers by the means of transvaginal endoscopy. After 4 to 6 days of in vivo culture embryos were re-collected either by non-surgical flushing of uterine horns (U-group) or by combined flushing of the oviducts and uterine horns (OU-group). In total the recovery rate was 38.4% (780/2029). After flushing at day seven, 106 blastocysts (blastocyst rate: 13.6% ) were found. The additional 24 h of in vitro culture (day eight) resulted in 153 blastocysts (blastocyst rate: 19.6% ). The recovery rate in the OU-group was twice as efficient as in the U-group (390/1358 vs. 390/671, P < 0.01). The recovery rates among the different stages of transferred embryos did not differ significantly; likewise cross-effects among the stages and the recovery methods were non-significant. The recovery methods (P < 0.001) and the interaction between the recovery methods and the stages of transferred embryos (P < 0.01) had an influence on blastocyst yields on day seven (U-group 37/1358 vs. OU-group 69/671) and day eight (U-group 48/1358 vs. OU-group 105/671). In Experiment II embryo quality was assessed by the survival rate of blastocysts after freezing in ethylene glycol. Day seven embryos were produced in vitro (in vitro group D7) or by IVM/IVF followed by a combined culture procedure (2 to 3 days in vitro prior to 4 to 5 days in vivo) (in vivo group D7) or after superovulation and collection at day seven (superovulation group). Embryos from in vitro group D7 re-expanded only for 6 h after thawing, embryos from in vivo group D7 and superovulation group were alive for 24 h and 72 h of culture, respectively. Only embryos derived by superovulation showed hatching activity. Blastocysts from the in vitro group D7 and the in vivo group D7 that were held in culture medium for additional 24 h (day eight) showed an analogous post-thawing culture behaviour. In conclusion, the results of the present study demonstrated that some embryos transferred for in vivo culture remain in the oviduct even at day seven. Hence, combined flushing of oviducts and uterine horns after in vivo culture in the bovine oviduct is necessary for effective embryo re-collection. The quality of recovered embryos after temporary in vivo culture assessed by cryotolerance was in-between those produced in vitro or recovered after superovulation.

Green alder effects on the forest soils in higher elevationsOriginal Paper

V. V. Podrázský, I. Ulbrichová, I. Kuneš, J. Folk

J. For. Sci., 2005, 51(20):38-42 | DOI: 10.17221/11847-JFS

Presented study documents the effects of green alder (Alnus alnobetula [Ehrh.] C. Koch) on the uppermost forest soil layers in mountain areas, respectively in the top part of the Orlické hory Mts. Three variants effect to the forest soil have been studied: pure groups of green alder, pure groups of Norway spruce and Norway spruce stand under-planted by green alder. The effect of alder stands litter influenced some basic soil characteristics: the surface humus accumulation (low), the bases content and base saturation (decreased). The green alder increased the acidification trends in the forest soils of the humus forms on the studied locality and intensified the mineralization and nutrient losses from the soil profile.

Factors of wine demand in the Czech Republic and in the neighbouring wine-growing countries

R. Kučerová

Agric. Econ. - Czech, 2005, 51(9):403-410 | DOI: 10.17221/5127-AGRICECON

The paper is focused on the analysis of the wine demand and chosen factors which influence the wine demand in the Czech Republic, in Slovakia, in Austria, and in Germany. In the Czech Republic, the wine consumption per inhabitant went up slightly in 1994-2003, the wine demand has a rising trend. The wine demand has the rising trend in Germany as well. In Slovakia, the year wine consumption per inhabitant decreased by 14.9% from 1994 to 2003; in Austria by 7.7%. There is a downward trend of development in these countries. The influence of the analyzed factors on the development of the wine demand is different in the particular countries. The dependence is possible to follow at the total level of incomes in comparison with the consumer's price of wine.

A survey of rats and mice for latent toxoplasmosis inCroatia: a case report

V. Kuticic, T. Wikerhauser, D. Gracner

Vet Med - Czech, 2005, 50(11):513-514 | DOI: 10.17221/5657-VETMED

Academyof Sciences and Arts,Zagreb,Croatia ABSTRACT: Brain tissues of 142 rats and 86 mice were bioassayed for toxoplasms. Each tissue was homogenized and subcutaneously injected into 4 SPF mice. Six weeks later, the mice were euthanatized and their brains were examined microscopically for Toxoplasma gondii tissue cysts. Two (1.4%) of the rats but none of the mice were positive. This is the first isolation of T. gondii from rats inCroatia.

Damage to peach and apricot trees in selected localities of Slovakia

H. Ivanová, G. Juhásová, Š. Čerčer

Hort. Sci. (Prague), 2005, 32(4):123-128 | DOI: 10.17221/3778-HORTSCI

In this paper we have evaluated the health condition of Prunus persica (L.) Batsch and Prunus armenia-ca L. for the occurrence of the parasitic microscopic fungus Cytospora cincta Sacc. Apricot trees in 5 localities with 10 sites and peach trees in 5 localities with 8 sites were evaluated. We identified symptoms of the disease in host plants, conditions for isolation and cultivation of the fungus and the growth rate of the mycelium hyphae on various substrates. The damage degree was evaluated in 330 trees in four localities while most trees were characterised by degree 1-3. We have derived conclusions for protective measures to prevent further spreading of the infection.

Dynamics of oak mycorrhizas

V. Pešková

J. For. Sci., 2005, 51(6):259-267 | DOI: 10.17221/4562-JFS

A decline of macromycetes, especially of ectomycorrhizal species, has been described in the last decade in various parts of Europe. These changes are attributed to direct or indirect effects of air pollution. In Central Europe these changes correlate with visual damage of forest. Many ectomycorrhizal fungi seem to be very suitable bioindicators of the disturbance of forest ectotrophic stability. Stages of this disturbance can be linked directly to particular phases of impoverishment of ectomycorrhizal mycocoenoses. These conclusions have been obtained from long-term research on permanent plots (1,000-2,500 m2) in spruce and oak forests in the Czech Republic, but it seems that they are valid generally. For the quantification and study of mycorrhizal activity a special method has been developed and applied. The analyses of mycorrhizas from the same plots in the period 2000-2002 indicate large mycorrhizal dynamics. These data correlate with data obtained from a fruiting bodies survey. Both the percentage of ectomycorrhizal species and the ratio of active mycorrhizas are highly sensitive to outer impacts (air pollution, acidification, fertilization). Their decrease is in correlation with the strong defoliation of trees and can be used for the prediction of further development in comparable stands.

Chloramphenicol resistance genes in Salmonella enterica subsp. enterica serovar Typhimurium isolated from human and animal sources in Hungary

N. Nogrady, I. Gado, P. Zsolt Fekete, J. Paszti

Vet Med - Czech, 2005, 50(4):164-170 | DOI: 10.17221/5609-VETMED

The presence of the chloramphenicol resistance genes cat, cmlA, flo, and the role of plasmids and class 1 integrons in the spread and persistence of chloramphenicol resistance were investigated on a collection of 40 Salmonella enterica serovar Typhimurium strains isolated from animals and humans in Hungary, by PCR and conjugation. Three groups of chloramphenicol resistant strains were identified. Eleven animal and 13 human isolates harboured the flo gene, encoding resistance to chloramphenicol and florfenicol, and possessed integrons of 1.0 Kb and 1.2 Kb typically found on the multidrug resistance island of S. Typhimurium DT104. Fifteen human strains had two different chloramphenicol resistance genes: the catB3 gene, identified as a gene cassette within a 1.45 Kb integron, and the catA gene, both of which were located on and transferred by a 140 Kb plasmid from a representative strain to the E. coli recipient via conjugation. A single animal strain had the catA gene alone, which was also transferred by a 35 Kb plasmid via conjugation. These three groups of strains belonged to three distinct genetic clusters, as it was revealed by macrorestriction analysis of 18 selected strains. This study provides information on the versatile genetic background of the chloramphenicol and florfenicol resistances in S. Typhimurium in Hungary and points to the significance of mobile genetic elements such as conjugative R-plasmids and integrons in the spread and persistence of chloramphenicol resistance genes. The results also indicate the predominance of the flo gene among animal strains and its appearance among human strains inHungary.

Application of Mg-fertilizers to prevent and to decrease Norway spruce yellowingOriginal Paper

V. V. Podrázský, S. Vacek, J. Remeš, I. Ulbrichová

J. For. Sci., 2005, 51(20):43-48 | DOI: 10.17221/11848-JFS

Yellowing of the Norway spruce is a relatively common problem in many areas of the Czech Republic. In some of them, it is also connected with forest decline; it was studied in the Šumava (Bohemian Forest) Mts. and in the western part of the Krušné hory Mts. This unfavourable phenomenon is initiated by several ecological as well as anthropic processes, one of the most important being the imbalance of forest stand nutrition. Particular reasons lead to the deficiency of nutrients, especially of magnesium. Solution of this undesirable trend is the profound ecological analysis and cause-oriented treatments. Besides lowering the air pollutant input, fertilization with deficient nutrients is a successful treatment in the forest stand management in affected areas. In the areas of interest, the application of a relatively small amount of appropriate fertilizer (SILVAMIX Mg) led to considerable improvement in the defoliation dynamics and yellowing progress since the first years after use.

Performance and gene effects for wheat yield under inoculation of arbuscular mycorrhiza fungi and Azotobacter chroococcum

R. Singh, R.K. Behl, K.P. Singh, P. Jain, N. Narula

Plant Soil Environ., 2004, 50(9):409-415 | DOI: 10.17221/4052-PSE

The present investigation was conducted to know the impact of bio-inoculants in low input field conditions on the magnitude and direction of gene effects and mean performance of some morphological and productivity traits in three wheat cultivars WH 147 (medium mineral input), WH 533 (drought tolerant), Raj 3077 (drought tolerant) and six generations namely P1, P2, F1, F2, BC1 and BC2 of three crosses i.e. WH 147 × WH 533, WH 533 × Raj 3077 and WH 147 × Raj 3077. The experiment was conducted in randomised block design with three replications and three treatments i.e. control (C, without inoculation), inoculation with arbuscular mycorrhiza fungi (AMF, Glomus fasciculatum), and AMF + Azotobacter chroococcum (Azc). Mineral fertilizer (80 kg N/ha + 40 kg P/ha + 18 kg ZnSO4/ha) was applied in all the three treatments. The application of bio-inoculants, AMF and AMF + Azc had a positive effect on plant height, peduncle length, grain yield, biological yield and harvest index in various populations of all the crosses. However, in some of the generations the impact of bio-inoculants was insignificant. The joint scaling test revealed that additive-dominance gene effects were mainly operative in governing expression of peduncle length, tillers per plant, plant height, grains/spike, grain yield and all traits except days to flowering and harvest index in crosses WH 147 × WH 533 and WH 533 × Raj 3077. The application of bioinoculants influenced gene effects for days to flowering, days to maturity, flag leaf area, spike length, grains/spike, 1000 grain weight and harvest index where complex genetic interactions were changed to simple additive-dominance gene effects in the cross WH 147 × Raj 3077. Likewise, additive-dominance gene effects were altered and digenic interactions exhibited for days to maturity, flag leaf area in WH 147 × WH 533 and days to flowering, plant height, flag leaf area in WH 533 × Raj 3077. Flag leaf area and plant height were governed by additive gene effects while for days to maturity and 1000-grain weight both additive and dominance gene effect were important. Duplicate epistasis was important in all the three crosses for days to flowering and harvest index and in the cross WH 147 × Raj 3077 for grain weight grains per spike and flag leaf area.

Influence of chronic administration of zearalenone on the processes of apoptosis in the porcine ovary

K. Wasowicz, M. Gajecka, J. Calka, E. Jakimiuk, M. Gajecki

Vet Med - Czech, 2005, 50(12):531-536 | DOI: 10.17221/5661-VETMED

Zearalenone (ZEA), a micotoxin produced by Fusarium sp. is regarded as a phytoestrogen. Although cytotoxic and genotoxic activity of ZEA was detected, the majority of its toxic influence is related to the ability of binding to estrogen receptors and disrupting the endocrine regulation of the reproductory functions in females. It was previously found that ZEA inhibits proliferation of cells in porcine ovaries, as detected with immunostaining for proliferating cells nuclear antigen (PCNA). The number of PCNA-positive cells was inversely proportional to the dose of ZEA. We decided to answer the question of whether ZEA induces apoptosis in porcine ovaries. Experimental gilts (before first estrus) were fed ZEA in a dosage of 20 (group II) or 40 (group III) µg/kg of body weight/day for 63 days. Control animals (group I) were fed a placebo. After that period animals were sacrificed, ovaries were extirpated, fixed in paraformaldehyde solution, cut into sections with a cryostat and studied for apoptosis with TUNEL kit, and for the presence of apoptosis-promoting protein Bax with immunohistochemistry. It was found that apoptosis was detected with TUNEL only in medium-sized antral ovarian follicles in animals of groups I and II. No apoptosis signal was found in the ovaries of animals in group III. No differences in the distribution and intensity of staining for Bax were found between animals of all investigated groups. The results indicate that ZEA do not induce apoptosis in porcine ovaries, and the inhibition of proliferation must be associated with other mechanisms.

Cryoprotection of porcine cornea: a scanning electron microscopy study

A. Neronov, P. Giurov, M. Cholakova, M. Dimitrova, E. Nikolova

Vet Med - Czech, 2005, 50(5):219-224 | DOI: 10.17221/5618-VETMED

Porcine corneas were frozen with Me2SO, glycerol, 1,2-propanediol and PEG-400. The effects of the range of concentrations (5% and 10%) and temperature regimen (1ºC/min and 5ºC/min) were investigated. The integrity of corneal endothelial cells was evaluated by scanning electron microscopy and trypan blue staining. The presence of 5-10% PEG-400 in the protective medium was the most effective in minimizing changes in the integrity of the corneal endothelium during freezing-thawing procedures.

Function of complement regulatory proteins in immunity of reproduction: a review

J. Valentovičová, M. Simon, J. Antalíková

Czech J. Anim. Sci., 2005, 50(4):135-141 | DOI: 10.17221/4007-CJAS

Humoral immunity has an important role during the maturation and development of the functional properties of spermatozoa. Spermatozoa may be exposed to antisperm antibodies in semen and in cervical, ovarian follicular and fallopian fluid. Antisperm antibodies can be complement-fixing or non-fixing and may affect the reproductive functions in a number of ways. Although the antisperm antibody alone can cause sperm agglutination, complement fixation is required for their immobilization. Therefore, the complement activation might be a "keystone" for the better understanding of "sperm humoral immunity" and some types of infertility. Recently, three cell surface molecules (CD molecules - CD46, CD55, CD59) present on many tissues in male and female reproductive tracts and gametes have been identified. These proteins belong to the family of complement regulatory proteins which could regulate the function of a complement system by cleavage of complement cascade in discrete sites of both activation ways (classical and alternative). In this review, the particular mechanisms of activity of complement regulatory proteins are presented as well as their function in a fertilization process and expression in human and animal tissues and organs.

Biomass functions applicable to European beech

E. Cienciala, M. Černý, J. Apltauer, Z. Exnerová

J. For. Sci., 2005, 51(4):147-154 | DOI: 10.17221/4553-JFS

This material describes parameterization of allometric functions applicable to biomass estimation of European beech trees. It is based on field data from destructive measurements of 20 full-grown trees with diameter at breast height (dbh) from 5.7 to 62.1 cm. The parameterization was performed for total tree aboveground biomass (AB; besides stump), stem and branch biomass, respectively. The allometric functions contained two or three parameters and used dbh either as a single independent variable or in combination with tree height (H). These functions explained 97 to 99% of the variability in the measured AB. The most successful equation was that using both dbh and H as independent variables in combination with three fitted parameters. H, as the second independent variable, had rather a small effect on improving the estimation: in the case of AB, H as independent variable improved prediction accuracy by 1-2% whereas in the case of branch biomass by about 5%. The parameterized biomass equations are applicable to tree specimens of European beech grown in typically managed forests.

Pest status of the leafhopper Empoasca dolichi Paoli on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria

Elizabeth Agbenu Egwurube, Michael Ogunleke Ogunlana, Michael Chidozie Dike, Isa Onu

Plant Protect. Sci., 2005, 41(4):158-164 | DOI: 10.17221/2754-PPS

Population studies and tests on the relationship between density and damage were conducted in 1999 to 2001 to determine the pest status of Empoasca dolichi on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria. Analyses showed that Empoasca numbers varied significantly from one year to another, and within each year the numbers of leafhoppers observed at the different growth stages of the plant were significantly different (P = 0.01). There was an inverse and highly significant relationship between the mean kernel yield and the Empoasca damage at the different growth stages of the plant. When natural population densities were plotted against economic injury level (EIL), the densities did not reach the EIL throughout the groundnut growing seasons. The insect was thus not an economic pest on groundnut in Zaria during the period of the study.

Measurement of pressure in hydraulics system of the ZTS 160 45 tractor

Z. Tkáč, J. Jablonický, R. Abrahám, J. Klusa

Res. Agr. Eng., 2005, 51(4):140-144 | DOI: 10.17221/4916-RAE

This contribution is oriented on the field of dynamic loading analysis of three-point hitch of tractor hydraulic pump. The hydraulic pump is placed in circuit of three-point hitch of the tractor ZTS 160 45. Obtained data from operation experiments will be applied for simulation of dynamic loading of the tested hydraulic pump. The measurements were realized during position control with ploughing sets: tractor ZTS 160 45 + plough 5-PN-30 and tractor ZTS 160 45 + plough 7-PHX-35. During the test physical and mechanical properties of soil and operating parameters of ploughing sets were investigated. Pressures of hydraulic system were in range from 3.2 to 7 MPa at aggregation with plough 5-PN-30 and hydraulic pump was loaded. Pressures of hydraulic system during ploughing with ploughing set tractor ZTS 160 45 + plough 7-PHX-35 were in range from 1.8 to 14 MPa and two times hydraulic pump was unloading in time 2 seconds.

Construction of a knowledge based portal for agribusiness

J. Havlíček, L. Dömeová, I. Tichá

Agric. Econ. - Czech, 2005, 51(11):495-502 | DOI: 10.17221/5144-AGRICECON

Virtual portal (VIPO) is designed to provide users with a single-point access to information, and tools to support their decision-making. VIPO illustrates the best practice presented in terms of case studies coded along three dimensions: field, domain and objectives. The second major source of knowledge is based on software packages made available to users including tutor support. The third part of the portal provides useful links to the existing databases which have the potential to facilitate decision making in agribusiness. All three pillars of the VIPO are complemented by on-line consultancy services.

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