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Results 4651 to 4680 of 4875:

Discrimination of vegetation from the background in high resolution colour remote sensed imagery

P. Surový, N.A. Ribeiro, A.C. Oliveira, Ľ. Scheer

J. For. Sci., 2004, 50(4):161-170 | DOI: 10.17221/4611-JFS

Different transformations of RGB colour space were compared to develop the best method for discrimination of vegetation from the background in open pure cork oak stands in southern Portugal in high-resolution colour imagery. Normalised difference index, i1i2i3 colour space and other indices developed for classic band imagery were recalculated for near infrared imagery and tested. A new method for fully automated thresholding was developed and tested. The newly developed index shows the equal accuracy performance but provides the smallest overestimation error and retains the largest scale of grey levels for a subsequent shape analysis.

Financing of forestry from public funds in the Czech Republic, Estonia, Poland and Slovenia - policy context, organisation and supported activities

A. Kaliszewski

J. For. Sci., 2004, 50(4):181-189 | DOI: 10.17221/4613-JFS

The paper describes the policy, legislative and organisational context and structure of financing the forestry from public funds in the Czech Republic, Estonia, Poland and Slovenia in the 90's. The first half of the nineties was the period of the most significant changes, whereas more stable and systematic financing of forestry was generally started in the second half of the nineties. The supported activities reflected main problems and challenges facing the forestry in individual countries. In the Czech Republic the substantial support was designed for protective measures and restitution of damaged stands. In Poland, the increase of forest area and restitution of forest stands damaged by air-pollution were the priority. Slovenian budget supported mainly the improvement of road infrastructure, forest management planning, as well as sustainable utilisation of forests through marking of trees for cutting. Estonian forestry received the relatively lowest subsidies allocated mainly to the preparation of management plans and extension services. Subsidies were the most important instruments of support. In Poland, however, tax exemptions and concessions were significantly higher than the value of financial means allocated from the public funds.

Real potentials of social forest functions of selected forest stands at Židlochovice Forest Enterprise

P. Kupec

J. For. Sci., 2004, 50(4):190-198 | DOI: 10.17221/4614-JFS

Social functions of forests were evaluated at Židlochovice Forest Enterprise by applying the method of Vyskot et al. (1996-2002). Real potentials of social forest functions were determined for all stand groups included in a forest management plan (FMP). The results of evaluation were processed in a database and projected in GIS. Tables and charts were used for the evaluation of results. We can claim on the basis of the results that the forest stands of the examined area are characterized by a very high potential to fulfil a bio-production social function. On the contrary, they have a low potential to fulfil social functions of ecological stabilization and edaphic soil conservation and hydric-hydrological function. The results of evaluation of the real potentials of social forest functions at Židlochovice Forest Enterprise are represented by the forest stands of management group No. 19 of forest management plan area Židlochovice.

Larch crown diseases in Trentino and South Tyrol

G. Maresi, P. Capretti, P. Ambrosi, S. Minerbi

J. For. Sci., 2004, 50(7):313-318 | DOI: 10.17221/4628-JFS

Various attacks of pathogenic fungi on the larch crown were observed in Trentino/South Tyrol, Italy, over the past few years. In 1999, severe defoliation was caused by Mycosphaerella laricina, a rarely investigated pathogen, whose action was enhanced by high temperatures and humidity in August. In July 2000, larch woods showed crown yellowing due to Meria laricis. Lower temperatures and heavy precipitation were probably the predisposing factors in this case. Hypodermella laricis was observed in 2002 as a localised attack, while Lachnellula wilkommii is commonly recorded. The impact of these diseases and the environmental factors involved in their occurrence are discussed in this paper.

Dothistroma needle blight Mycosphaerella pini E. Rostrup, a new quarantine pathogen of pines in the CR

L. Jankovský, M. Bednářová, D. Palovčíková

J. For. Sci., 2004, 50(7):319-326 | DOI: 10.17221/4629-JFS

Dothistroma needle blight caused by Mycosphaerella pini E. Rostrup was observed for the first time in the Czech Republic on an imported Pinus nigra Arnold in 1999. In 2000, it was also found in the open planting. During three years, it became an important pathogen of pines in the Czech Republic. Its occurrence was noticed in more than 50 localities, above all in the region of Moravia and Silesia and eastern Bohemia. In total, it was found on 10 species of pine (P. nigra Arnold, P. banksiana Lamb., P. contorta Loudon, P. mugo Turra, P. leucodermis Ant., P. sylvestris L., P. cembra L., P. aristata Engelm., P. ponderosa P. et C. Lawson and P. jeffreyi Grev. et Balf.). Also Picea pungens Engelm. was noticed as a host species. In the Czech Republic, Pinus nigra is the most frequent host species of M. pini (80% localities) followed by Pinus mugo (27% localities). On Scots pine P. sylvestris, M. pini was noticed at two localities. The critical period for infection is in the Czech Republic from the second half of May until the end of June. The incubation period lasts about 2-4 months depending on climatic conditions. The first symptoms on the needles infected in the current year appear in August being clearly expressed from September to November.In the CR, Dothistroma needle blight spread probably with infected planting stock obtained from import at the end of the 80s and at the beginning of the 90s.

Influence of amphibolite powder and Silvamix fertiliser on Norway spruce plantation in conditions of air polluted mountains

I. Kuneš, V. Balcar, M. Čížek

J. For. Sci., 2004, 50(8):366-373 | DOI: 10.17221/4663-JFS

The objective of the paper is to assess the effects of amphibolite powder (waste from a dust removing process in a rock pulveriser) and Silvamix slow release fertiliser on Norway spruce plantation in the harsh physical environment of the Jizerské hory Mts. The plantation characteristics such as mortality, annual height increment, stem base diameter, crown diameter and nutrient analyses are evaluated. A nine-year-long period of observation is summarised. The effects of both the forms of chemical amelioration seem to be positive and statistically significant. The benefits of the amelioration expressed in absolute figures have been easily observable until now. Recently, the importance of these benefits has decreased after the adaptation of planted trees to the mountain site and natural acceleration of their annual increment.

Possibilities of influencing the rooting quality of Norway spruce (Picea abies [L.] Karst.) cuttings

A. Jurásek, J. Martincová

J. For. Sci., 2004, 50(10):464-477 | DOI: 10.17221/4642-JFS

The influence of the date of cutting collection and cutting position in the crown on rooting quality was evaluated in cuttings taken from seven-year ortets. The evaluation of various dates of cutting collection in spring demonstrated a possibility of successful propagation by cuttings during a relatively long period from full bud dormancy to flushing onset. The relationship between the development of aboveground parts (flushing, shoot and bud formation) and rooting quality was not established. The exposure of cuttings in the crown of parent tree with respect to the cardinal points did not influence rooting percentage and quality. A somewhat higher rooting ability was observed in cuttings from lower parts of the crown in comparison with cuttings taken from the highest whorls. Differences were more perceivable in generally weak-rooting clones. The comparison of rooting quality in cuttings from seven- and eight-year mother plantations with cuttings from a sixteen-year mother plantation confirmed that not only the rooting of cuttings collected from older mother plantations is weaker but also their growth is slower and their plagiotropic growth continues for a longer time.

XII. World Forestry Congress

K. Vančura, S. Vacek

J. For. Sci., 2004, 50(11):497-499 | DOI: 10.17221/4645-JFS

XII. World Forestry Congress have been held in Quebec, Canada from September 21 to 28, 2003. Forestry issues were discussed on three basic areas: Forests for People, Forests for the Planet, People and Forests in Harmony. The Czech Republic was represented by 9 contributions.

National Forestry Programme of the Czech Republic in brief

K. Vančura

J. For. Sci., 2004, 50(11):500-504 | DOI: 10.17221/4646-JFS

The basic principle from which the Czech National Forestry Programme proceeds is the management of forests in a permanently sustainable manner whilst limiting the administrative interference of the state to the unavoidable minimum under the circumstances of the motivating operation of state forestry policy for the support of public interests and whilst increasing the responsibility of forest owners for their property. The National Forestry Programme is supposed to be an interdepartmental and intersectoral programme respecting not only the needs for the branch development of forest management, but also emphasising the place of forests in the environment and landscape creation, non-production functions of forests, the importance of the forest as a renewable source of ecologically advantageous raw material and the significance of the use and processing of wood for the economy of the country and thus for the society as such. The first idea of National Forestry Programme has been presented in 1993. The current version of the Programme has been conceived for the period 2003-2006. In addition to the basic information about the current state of forests and forestry management in the Czech Republic, it contains chapters with themes focussing on forestry problem issues.

Development of the Czech forest related policy and institutions in the threshold of the 3rd millennium

K. Vančura, P. Pacourek, J. Řezáč

J. For. Sci., 2004, 50(11):505-509 | DOI: 10.17221/4647-JFS

This paper gives an overview of Czech forestry policy and legislation since the beginning of changes in the CEEC plus developments and activities of the main forestry institutions. These activities are referred to in the background material given for the political transition period and also related to the Pan-European and global forestry processes. The philosophy of forestry in the Czech Republic is based on the international framework set out by the first Ministerial Conference on the Protection of Forests in Europe and also in conjunction with the preparation of the Czech Republic for accession to the European Union. National and regional forest programmes are aimed at implementing the principles of sustainable forest management and a broad range of stakeholders from the forestry and environment sectors has been involved in its preparation. The current situation and main problems of forestry are given along with basic principles on how to solve such problems and also on how to fulfil obligations to future generations, and international commitments.

Development of forest stands condition and its monitoring in the Czech Republic

P. Fabiánek, V. Henžlík, K. Vančura

J. For. Sci., 2004, 50(11):514-519 | DOI: 10.17221/4649-JFS

In 1986, the UN ECE established the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (hereinafter ICP Forests) to respond on the growing concern about forest damage caused since the beginning of eighties by air pollution load. Pan-European grid of the (ICP Forests) monitoring plots represents one of the most important systems of forest ecosystems assessing and checking. The Czech Republic is unfortunately well known due to this problem and so the country joined ICP Forest Programme since the very beginning. The paper presents general information on Czech forest stand condition that gained through various methods in the past as well as in the frame of ICP Forests. The participation in the International Cooperative Programme on Assessment and Monitoring of Air Pollution Effects on Forests (ICP Forests) represents a contribution of the EU candidate country to the fulfillment of the Reg. (EEC) No. 3528/86. However it seems that effects and importance of air pollution are decreasing, a lot of new stress situations exists and there is a need for continuing the programme.

Sustainable management of mountain forests in the Czech Republic

S. Vacek, V. Balcar

J. For. Sci., 2004, 50(11):526-532 | DOI: 10.17221/4651-JFS

Forest management in the Czech Republic (CR) was not shaped in the environment of natural forests but in the territory that was influenced by unregulated felling and animal grazing for a long time. Hence the fear for sustainable and balanced benefits from forests endangered by long-term uncontrolled exploitation was legitimate. Almost after three centuries of application of the sustainability principle, forests are considered not only as a source of renewable wood raw material but also as a tool of the environment formation. Mountain forests are an important landscape component of this country. They are an object of specific importance from the aspect of natural environment conservation, stabilization of natural processes and general landscape homeostasis. In addition, they fulfil a number of production and non-production functions. Cardinal elements of sustainable forest management in the CR conditions are as follows: management of the forest as an ecosystem, i.e. transition from exclusive care of forest tree species and their stands to care of the whole forest ecosystems; restructuring (conversion, reconstruction) of damaged and declining forests; optimum (species, genetic, spatial, age) structure of forest ecosystems differentiated according to site conditions and management targets; differentiated transition from general management to group or individual methods; utilization and support of spontaneous processes such as natural regeneration, competition and other principles of self-regulation. The above cardinal elements of sustainable forest management are applicable to forests of the CR in general, but their importance considerably increases in mountain forests where many species survive on the margin of subsistence. Moreover, mountain forests of CR have been heavily destroyed by anthropogenic factors, especially air-pollution ecological stresses, during the last three or four decades.

Changes in free amino acids content in kochia (Kochia scoparia) resistant to ALS-inhibitorsOriginal Paper

Daniela Chodová, Jan Mikulka

Plant Protect. Sci., 2000, 36(1):15-19 | DOI: 10.17221/9615-PPS

Change in the community of epigeal spiders and harvestmen (Araneae, Opiliones) with the age of an apple orchard

S. Pekár

Plant Soil Environ., 2003, 49(2):81-88 | DOI: 10.17221/4094-PSE

Change in the community of epigeal spiders and harvestmen (Araneae, Opiliones) was studied in an experimental apple orchard for six consecutive years. Five plots were surveyed by pitfall traps. Four of the plots were young (1-4 years); one plot was older (15-20 years). The abundance of epigeal arachnids increased with the age on the young plots, while it was constant on the older plot. There were significantly more arachnids on the young plots than on the older one. In turn, the diversity was significantly lower on the young than on the older plots. Lycosidae, Phalangiidae and Tetra-gnathidae dominated the young plots. The older plots were richer in Agelenidae, Clubionidae, Dysderidae, Gnaphosidae, Linyphiidae, Pisauridae and Salticidae. Principal species of the young and older plots were identified using multivariate analysis.

Hop yield evaluation depending on experimental plot area under different nitrogen management

F. Bavec, B. Čeh Brežnik, M. Brežnik

Plant Soil Environ., 2003, 49(4):163-167 | DOI: 10.17221/4108-PSE

Numerous agricultural and associated ecological effects such as mineral nitrogen fertilising influence the yield of hop (Humulus lupulus L.) cones and its quality. Using a wide spacing of plants (in our case 2.6 × 0.8 m) we want to answer a hypothetical question about an appropriate number of test plants per plot vs. experimental plot area. The aim of this study was to compare the effect of different rates of mineral nitrogen, fertiliser combinations and their nitrogen split application on hop yield evaluated from different plot areas (micro trial: 30 plants per plot; macro trial: 320 plants per plot). Hop yield varied significantly between treatments, plot areas, years and interactions (year × treatment, plot area × treatment) (all at P £ 0.01). Cone yield in a micro trial was higher in all treatments in comparison with yield in a macro trial. In spite of common intensive fertilisation the appropriate fertilising combination and mineral N rate can influence the yield. Target nitrogen rate of160 kg mineral N/ha (at the level from 40.0 to62.5 kg nitrate N/ha in soil depth to0.3 m) and cheaper combination of calcium-ammonium nitrate (50 kg N/ha) at the beginning of vegetation plus urea (110 kg N/ha) for top dressing can be recommended. On plot areas of each size and each year all treatments showed similar trends of fertilising effect on yield. In spite of higher yield in the micro trial and lower coefficient of variation in comparison with the macro trial, the results proved that a risk of incorrect yield analysing in macro trials is very low for field experiments.

The intensity and quality of Internet usage in the agriculture sector and possibilities of its further development - Information

J. Jarolímek, J. Vaněk

Plant Soil Environ., 2003, 49(11):525-529 | DOI: 10.17221/4188-PSE

The level of the usage of information and communication technologies (ICT) has a direct influence on the development and competitiveness of individuals, firms, production sectors, regions and even the whole continents. The availability of ICT, including the Internet, to agricultural enterprises in theCzechRepublicis already very satisfactory. Due to the structure of agricultural enterprises the penetration of Internet technologies in theCzechRepublicis more intensive than in most EU countries. Therefore an urgent issue is the level of the usage of these technologies that is not an issue related to finances anymore but it is a problem related to the knowledge and habits of users and availability of information and services. The project of the portal for the agriculture sector and countryside AGRIS has a significant impact on the level of the usage of Internet information and services in the agriculture sector.

Barley response to the soil reserve of sulphur and ammonium sulphate in short-term experiments under controlled conditions of cultivation

J. Matula

Plant Soil Environ., 2004, 50(6):235-242 | DOI: 10.17221/4027-PSE

The objective of the paper was to determine an appropriate concentration of available sulphur in soil for the initial growth of plants. Based on previous researches two methods of soil extraction were used to acquire information on the soil reserve: water extraction (H2O 1:5, w/v) and extraction in 0.5M ammonium acetate with addition of NH4F (KVK-UF soil test). Spring barley was used as a test crop to determine the soil reserve of sulphur and its response to sulphur addition to the soil. A collection of 48 samples of topsoil from agriculturally important localities in the CR was made up for this purpose and the parameters of the nutrient status of the soil were remarkably different. A set of soils was used to establish short-time vegetation experiments in a plant growth chamber according to the scheme: A) control - without sulphur application and B) response variant with application of 30 mg S/kg of soil in the form of (NH)4SO4; nitrogen in variant A was adjusted by application of NH4Cl. Index of nutrient efficiency (IE = Y/N where Y = yield and N = nutrient concentration in the plant) and boundary lines of the point field were used to evaluate the efficiency of barley nutrition with sulphur. The efficient soil reserve of sulphur for the soil test H2O (1:5) when the ICP analytical technique was used was indicated in the range of 8-11 mg S/kg; 6-10 mg S/kg for sulphate detection on a SKALAR analyser. The efficient utilisation of sulphur by barley plants for the KVK-UF soil test was in the range of 7-12 mg S/kg. The conversion of the KVK-UF S-test to the index of soil reserve of sulphur by adding up a variable portion of the CEC value to the value of sulphur determined by the soil test (0.0167CEC + 9.1667) improved the closeness of the relationship between soil and plant.

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.

Research of sugar-beet tubers mechanical properties

J. Skalický

Res. Agr. Eng., 2003, 49(3):80-84 | DOI: 10.17221/4956-RAE

Approach to the problems of sugar-beet tubers surface damage dependence on harvesting technology. Investigation of sugar-beet tubers damage when falling on wood and iron surfaces and in the next case tuber damage caused by their fall on the tuber heap. Research of damage rate dependence on the fall height. Evaluation of damage rate was carried by the I.I.R.B. method (method used by all sugar-beet growing countries of Western Europe). The results refer that no considerable differences in damage rate after the fall on the wood or iron bottoms have been ascertained. The height of 1.5 m can be considered in all cases as the limit value of the tubers fall, when share of heavily damaged tubers reached acceptable values of 10-15%, but that the share increases significantly at higher falling height. The lifting bodies construction requires also a knowledge of dependence between root depth and force for tuber release from soil in relation to the tuber weight. Medium force needed for tubers lifting ranges from 17 to 27 kp, maximum value 50 kp was found out for tubers of weight above 3 kg.

Background information for the agricultural technology management program (Atmp) Agro-expert

B. Havrland

Res. Agr. Eng., 2004, 50(1):342-40 | DOI: 10.17221/4925-RAE

Economic efficiency in farming is achieved as a result of manager's skills and proper technologic equipment available on the farm suitable for carrying out husbandry operations. Applying skilled management to the whole business of farming is of an extraordinary importance, too. The manager should be equipped with more or less sophisticated software that would make his decision making process more professional and adequate to (generaly) production conditions. Such software (program) will allow proving his technological conception by economic calculations and proper tests. An Agricultural Technology Management Program AGRO-EXPERT has been conceived and is discussed in this paper. The authors analyze situation in appearance of such programs and conditions/information necessary for their correct (adequate) functions.

The present time of transposition of the European environmental legislation into Czech food industry

L. Macháčková, P. Heneman

Res. Agr. Eng., 2004, 50(3):112-116 | DOI: 10.17221/4936-RAE

The accession of the Czech Republic in the European Union has brought a necessity to adopt a range of new legal regulations and to apply them in our conditions. Their application however connects with a highly demanding and complex process of implementation of the individual acts of law, administrative and time requirements. One of laws that had to be adopted is the Act No. 76/2002 Coll. on integrated prevention and pollution control, on the integrated pollution register and on amendment to some Acts (hereinafter the IPPC Act). The Act imposes an obligation for all operators of various industrial and processing plants working at certain production or processing capacities have to obtain a so called integrated license without which their activities will not be permitted to continue in the future. At the beginning of the integrated licensing procedure, each subject concerned by the Act is obliged to file an application for the integrated license at a relevant regional authority. There is an analysis of the present time of the IPPC problems in Czech food industry. At the present time, the procedure of licensing and applications for the integrated license are at various stages of the process in individual enterprises.

Influence of heat treatment on mechanical properties of steel

R. Chotěborský, M. Brožek

Res. Agr. Eng., 2004, 50(4):152-155 | DOI: 10.17221/4942-RAE

This article concerns an influence of heat treatment on strength and toughness of steel. The partial results of tests on steel 12 042 are presented.

Novel Strecker degradation products of tyrosine and dihydroxyphenylalanine

J. Adamiec, K. Cejpek, J. Rössner, J. Velíšek

Czech J. Food Sci., 2001, 19(1):13-18 | DOI: 10.17221/6568-CJFS

Tyrosine was oxidised with either potassium peroxodisulphate or glyoxal. Volatile reaction products were isolated and analysed by GC/FID and GC/MS, derivatised with diazomethane and analysed by the same methods. Eight reaction products were identified. The major products were the expected Strecker aldehyde (4-hydroxyphenylacetaldehyde) and its lower homologue 4-hydroxybenzaldehyde. They were followed by 1-(4-hydroxyphenyl)-3-propionaldehyde, phenylacetaldehyde, benzaldehyde, phenol, 4-hydroxybenzoic, and benzoic acid. Analogously, the oxidation of 3,4-dihydroxyphenylalanine yielded the corresponding Strecker aldehyde (3,4-dihydroxyphenylacetaldehyde), its lower homologue 3,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic, 3,4-dihydroxyphenylacetic, and caffeic acid. An identification of these oxidation products of tyrosine and 3,4-dihydroxyphenylalanine assumes homolytic cleavage of the Strecker aldehydes and a recombination of free radicals formed by this cleavage. As minor products, six O- and N-heterocyclic compounds arose in systems containing glyoxal (pyrazine, methyl- and ethylpyrazine, 3-furancarbaldehyde, 5-methyl-2-furancarbaldehyde, 2-pyrrolcarbaldehyde).

Strecker degradation products of aspartic and glutamic acids and their amides

J. Rössner, J. Velíšek, F. Pudil, J. Davídek

Czech J. Food Sci., 2001, 19(2):41-45 | DOI: 10.17221/6573-CJFS

Aspartic and glutamic acids, asparagine and glutamine were oxidised with either potassium peroxodisulphate or glyoxal. Nonvolatile products were derivatised and analysed by GC/FID and GC/MS. Volatile reaction products were isolated and analysed by the same methods. It was found that the degradation reactions of amino acids are complex. Amino acids are principally degraded via the corresponding a-keto acids to Strecker aldehydes (aspartic acid to oxalacetic and 3-oxopropionic acids and glutamic acid to a-ketoglutaric and 4-oxobutyric acids), which are unstable and decomposed by decarboxylation to the corresponding aldehydes. Aspartic acid also eliminates ammonia and yields fumaric acid whereas glutamic acid gives rise to an imine, pyroglutamic acid. A recombination of free radicals leads to dicarboxylic acids (succinic acid from aspartic acid, succinic, glutaric and adipic acids from glutamic acid). The major volatile products (besides the aldehydes) are lower carboxylic acids (acetic acid from aspartic acid and propionic acid acid from glutamic acid) that can at least partly arise by radical reactions. In both quality and quantity terms, a higher amount of degradation products arises by oxidation of amino acids by peroxodisulphate.

Estrogenic effects of silymarin in ovariectomized ratsOriginal Paper

V. Kummer, J. Mašková, J. Čanderle, Z. Zralý, J. Neča, M. Machala

Vet Med - Czech, 2001, 46(1):17-23 | DOI: 10.17221/7846-VETMED

The objective of this study was to test whether silymarin induces changes indicative of estrogenic effects in gonadal organs of ovariectomized (OVX) rats. Silymarin was administered in two experimental groups of OVX rats (n = 7 + 7) for 30 days at the doses of 25 or 50 mg per animal per day. OVX rats (n = 7) receiving 5 µg of 17b-estradiol (E2) for the last three days before killing and untreated OVX rats (n = 7) were used as the positive and the negative controls, respectively. Uterine and blood samples were collected immediately after killing. Compared with the negative controls, total and normalized uterine weights were significantly higher in the two experimental groups (P < 0.01 and P < 0.05, respectively). Uterotrophic effects of silymarin were also evident from increased heights of the luminal epithelium (P < 0.01) and the endometrium (P < 0.05). The response was dose-independent within the tested range. The strongest uterine response was observed in the OVX rats treated with E2. A highly significant decrease in mean density of estrogen receptor (ERa) immunostaining in the luminal and the glandular endometrial epithelia (P < 0.01) and a stronger ERa immunostaining in stromal cells were observed in the two experimental and the positive control groups. The activities of alkaline and acid phosphatases were significantly increased in the luminal (P < 0.05) and the glandular (P < 0.01) epithelia only in the rats treated with E2. Both silymarin and E2 induced an increase in thyroid hormone concentrations in blood serum. The rises of free T3 and T4 were significant (P < 0.05) in the group receiving 50 mg of silymarin per day. Hepatic oxidative metabolism of steroids was assumed to be another target of the action of silymarin. The mitochondrial cytochrome P450-dependent testosterone hydroxylase activity and the cytochrome P4501A-dependent 7-ethoxyresorufin O-deethylase activity were significantly increased (P < 0.05) in the group receiving 50 mg of silymarin per day and in the E2-treated control group, respectively. However, the modulations of the CYP enzymes played only a minor role in the overall estrogenic effect of silymarin. Histological and functional alterations in the OVX rats treated orally with silymarin for 30 days were consistent with those seen in E2-treated rats and were indicative of estrogenic effects of silymarin.

Adoption of ICT in agricultural management in the United Kingdom: the intra-rural digital divide

M.F. Warren

Agric. Econ. - Czech, 2002, 48(1):1-8 | DOI: 10.17221/5280-AGRICECON

The benefits arising from adoption of information and communication technology by farming businesses are explored, and the prospect of a digital divide appearing in the UK agricultural sector is discussed, drawing on results of research at the University of Plymouth. It is proposed that countries in Central and Eastern Europe will be subject to the same phenomenon, and that the potential disadvantage suffered by non-adopters of this technology will be sufficiently severe to justify both policy intervention and further research.

Czech farmers facing agricultural policy in the period of revitalization

H. Hudečková, M. Lošťák

Agric. Econ. - Czech, 2002, 48(6):233-244 | DOI: 10.17221/5311-AGRICECON

The paper addresses the behaviour of Czech farmers in the frames (structures) created by the agricultural policy in Czechia during the period of the Czech agriculture revitalization. The theoretical background of the paper is formed by the duality of actor and structures. The text considers the ideas embedded in the rules of agricultural policy in investigated period as they are confronted with actual behaviour of the Czech farmers. The main assumption is that the circumstances of agricultural policy should primarily increase the competitiveness of the Czech agriculture. Because this issue is a new one, the qualitative approach to deal with these problems was exploited. In-depth (less standardized) interviews with representatives of six farms were conducted. These farms are typical by various strategies of action. The results focus on information about the level of systematic knowledge of agricultural policy, about the specific reactions to particular areas of this policy (incl. farmers evaluation of particular measures related to Czech integration into EU) and about experiences related to the SAPARD program implementation.

Diversification of individual farms in Slovakia with regard to production use patterns and level of income

G. Blaas

Agric. Econ. - Czech, 2003, 49(1):1-7 | DOI: 10.17221/5257-AGRICECON

During the years of transition to market economy, a variety of farming types has evolved in Slovakia. Corporate farming is still pursued on about 80 per cent of the total agricultural land area, but a gradual increase of individual farms can be observed. A large portion of the registered individual farms is producing both for the market and for the self-supply of households, but the importance of specialised commercial farms has been growing during the recent years. Their share in the total number of registered individual farms can be estimated as 25 per cent and they specialise as a rule on cash crop products. The average production area is 130 hectares, but income differentiation is wide-ranging within this group of farms. The lowest income strata (which represent about 50 per cent of these farms) receive eight times less income, than the highest one - represented by less than 2 per cent of cases.

Quantitative evaluation of the effect of economic tools on economic policies in the food industry of the SR

D. Matošková, V. Ižáková

Agric. Econ. - Czech, 2003, 49(1):14-21 | DOI: 10.17221/5259-AGRICECON

The article deals with the evaluation of competitiveness in milling, feedstuffs, pasta, spirits, wine, beer and malt industries in the Slovak Republic. It further evaluates the impacts of economic policy tools on the stated sections of food industry by means of the PAM analysis. The impact of the policies on income, costs and profits of food production in the selected food industry branches has been discovered, based on the effects of divergences and coefficients of nominal and effective protection.

The development of the price parity in the foodstuffs production and consumption vertical

M. Brodová, M. Ševčíková

Agric. Econ. - Czech, 2003, 49(1):30-36 | DOI: 10.17221/5261-AGRICECON

The analysis of the development of prices in the foodstuffs vertical, it means the prices of inputs into the agriculture, agricultural products, food products and consumption prices of foodstuffs, on the basis of the price scissors, and with crucial products on the basis of the price shares and differences, has shown that price liberalisation with the applied partial regulation of their development within the market-oriented reform has evoked the greatest raise of prices within 1991-2001 regarding inputs into the agriculture, while prices of agricultural products were growing slower. The parity coefficient (the ratio of price indices) between the development of the prices of inputs and outputs became worse as of 1989 to the detriment of agriculture from 93.9 reached in 1990 to 50.3 in 2001, what means a significant opening of the price scissors to the detriment of agricultural producers. That situation was influenced mostly by the development in the first year of the reform but the trend of opening the price scissors, except for 1994, was persisting, though in the last two years the differences in the trends of the development of prices of inputs and outputs have been moderated. At the beginning of the development, the effect of the low level of the agricultural products prices was not adequately reflected in the prices of food producers and consequently in consumer prices. This was influenced mainly by the pressure of food producers evoked by the need of settlement of additional costs connected with the transformation, in particular to the detriment of the agricultural products prices (opening of the price scissors with the parity coefficient dropping from 90.8 in 1990 to 56.5 in 2001), but this negative trend has been stopped in the last two years. A gradual accommodation of demand and supply and a growing competition environment also through large retails established in our country has been reflected in closing the price scissors between the prices of food producers and consumer prices of foodstuffs (the parity coefficient raised from 76.6 in 1991 to 88.7 in 2001). The development of the shares and differences in prices as of 1994 pointed to a substantial differentiation in the development of prices in the vertical of the production and consumption of individual products what was effected by the applied regulation system as well. With milk and milk products, the majority of the evaluated products was showing a slightly raised share of the raw cow milk price in the final food products prices, and in the last three years, also the processor price share in the consumer price. This narrowed the difference between the producer and dealer prices. With slaughter cattle and the major kinds of beef, a gradual decline of the slaughter cattle price share in the processor price was interrupted in 2001, what, to a certain extent, was also caused by the crisis evoked by the BSE and by the minimum price which prevented transferring of these consequences, to a larger extent, to farmers. Similarly, in 2001, a non-standard situation occurred between the processor and consumer prices of the individual kinds of beef. With slaughter pigs and the evaluated kinds of pork, after the period of dropping slaughter pig prices share in the processor price of the major kinds of pork, its growth was

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