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Immunoglobulins and lactoferrin concentration in milk and bacteria causing subclinical mastitis in dairy cows
2005
Kocina, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:iveta.kocina@pvd.gov.lv | Antane, V.(Latvia Univ. of Agriculture, Jelgava (Latvia)) | Lusis, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Natural defence mechanisms of the mammary gland tissues play a vital role in protecting the gland from infections. The progress of mammary infection depends on the ability of bacterial pathogens to adapt to milk and udder tissues, and on the various virulence factors they activate, as well as on the cow's response. The levels of immunoglobulins (lg) and lactoferrin (Lf) concentration in the milk from dairy cows with and without subclinical mastitis were determined. In this investigation it was stated that 82.5% of samples were negative, but 17.5% of samples were positive for pathogens. Cows had subclinical mastitis caused by Coagulase negative staphylococci observed in 48.60%, Streptococcus uberis - 32.10%, Staphylococcus aureus - 18.90% of cases in milk samples. There were no significant differences between all classes of immunoglobulins concentration in the milk without pathogens and with pathogens. The lactoferrin concentration was significantly increased for 40.33% in the milk with pathogens.
Afficher plus [+] Moins [-]Competence in higher education in multi-dimensional aspect
2005
Tomsons, V.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:Vilnis.Tomsons@llu.lv
The term "competence" has not been clearly defined in the literature. Two meanings of the term have been identified. One refers to the outputs or results of education (training), but other - to the inputs or underlying attributes needed for a person to demonstrate competent performance. Each meaning has been used to describe both individual and organizational competences. A classification of the meanings of competence is given to show that the term has several meanings depending on the purpose for which it is used. Although competence is an important concept in education, it is unclear what competence is. Constructivism is a way out of the competence confusion - we don't search for one absolute true definition, but do use the competence concept for our own purposes. At the end of article a description (definition) of competence is given. This definition is appropriate to define inputs for undergraduate programmes and to improve student's lifelong and life wide learning competences while studying undergraduate study programmes.
Afficher plus [+] Moins [-]Arts education as pedagogical problem
2005
Luse, N.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:luseno@llu.lv
The purpose of arts education at university is to create students' attitude to five forms of art - literature, drama, dance, music, and visual arts. As a study object, the art an integral part of education and perception of art is the result of cognition of the surrounding environment. A.Dauge (1868-1937) and J.A.Students (1898-1964) observed that arts education is finding out the question of integrity the logically rational and the emotionally experienced in the system of counterbalancing mind and feelings. At the beginning of the 21 century, as the paradigm of education is changing, the opinion also changed about what makes a knowledgeable and socially valuable person. In order to promote the development of one's personality self-fulfilment pedagogues are called for introducing certain changes which are contributing to the opening up of their students. University students are going through the process of evaluation of an interpretation of opera as recorded performance on a video-type and in live performance on the opera house stage. It makes their opinion based on well - grounded argumentation and personally valuable self - evaluation. The last is functioning as the regulating mechanism for learning the properties of arts in the context of developing the human personality. The opera performance on the stage is the live communication with a different culture heritage and people are going to performances to be immersed in art values. Usually the repertoire is hosen for visiting the opera house as an interesting and enjoyable entertainment for students. Such masterpieces as "The Magic Flute" of W.A.Mozart, "Flying Dutchman" by R.Wagner, "Aida" and "La Travolta" by G.Verdi are actually stimulated the students discover of the artwork. Understanding of opera art increases the students' knowledge, emotional experience, interest and positive attitude to high art values. Arts education as intelligent cultural assessment is the dominating purpose of the teaching-learning process.
Afficher plus [+] Moins [-]Nitrogen, phosphorus and potassium influence on infections by arbuscular mycorrhizal fungi in Dactylis glomerata roots
2005
Druva-Lusite, I.(University of Latvia, Riga (Latvia))E-mail:mycorrhiza@gmail.com | Liepina, L.(University of Latvia, Riga (Latvia))E-mail:ligita@mail.lubi.edu.lv | Skujins, J.(University of Latvia, Riga (Latvia)) | Antonijs, A.(Latvia Univ. of Agriculture, Skriveri, Aizkraukle reg. (Latvia). Skriveri Research Centre)
The aim of this research was to compare effects of fertilization with various ratios of N, P and K (N:P:K) on arbuscular mycorrhizal fungi (AMF) infection in roots of Dactylis glomerata in Ca-carbonate (limed) and non-limed meadow plots at the Research Centre of Skriveri, Latvia University of Agriculture. Dactylis glomerata roots were excavated from variously fertilizer plots, a minimum 3 root samples per plot and analysed for two consecutive years. Arbuscular mycorrhizal fungi infection rates were estimated according to accepted scoring tables used for determination of AMF colonization.
Afficher plus [+] Moins [-]Insurance of the milking equipment washing regime in lowered environmental temperature
2005
Zujs, V.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:valdisz08@navigator.lv | Priekulis, J.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:Juris.Priekulis@llu.lv | Iljins, U.(Latvia Univ. of Agriculture, Jelgava (Latvia)E-mail:Uldis.Iljins@llu.lv
In Latvia, use of unheated cow sheds with lowered environmental temperature is growing. In such circumstances, cooling of the milking equipment washing liquid is more rapid and quality of the washing equipment decreases. However, it may be eliminated by coating the milk and washing liquid piping with heat insulation. A mathematical model of the milking equipment washing liquid by which the end temperature of the washing liquid cooling can be determined is developed. Two types of heat insulation materials are under the trial. Laboratory experiments on cooling of the washing liquid are carried out and the experimental coefficients of the mathematical model are determined.
Afficher plus [+] Moins [-]System modelling of the grain drying process
2005
Arhipovs, S.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:sergejs.arhipovs@llu.lv
One of the prior trends of research is the problem studies of power economy of technological processes and quality automatic control. Though the theory of grain drying process has been developed profoundly, still there are problems in its implementation. The developed analytical and simulation models of grain drying are difficult to implement into practice because they do not contain all the factors, which influence the real grain drying process or they cannot be solved. The developed models enable to assess only the essentiality of factors and/or the fundamental basics of the process. In order to ensure the effective and user-friendly grain drying process, it is indispensable to develop the control methodology using system modelling approach. The present paper deals with the system approach to heat and mass transfer problem and the testing of the basic hypothesis of the diffusion theory about the normal distribution of particles in the diffusive environment.
Afficher plus [+] Moins [-]Stalk material cutting energy
2005
Smits, M.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:mareksmi@llu.lv | Kronbergs, E.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Systainable energy systems and food security can be obtained in rural areas by usage of renewable energy resources and development of agro-ecotechnologies. Substitution of fossil feedstock for energy and raw materials by biomass is important measure also for greenhouse gas (GHG) emission mitigation. The article presents investigation of reed biomass size reduction processes flattening and cutting. The necessity to reduce the size of common reeds (Phragmites australis) to particles smaller than 3 mm for solid biofuel production is determined by compaction properties of biomass. It was stated that unflattened reed stem cutting energy consumption is 2 times more than flattened stem cutting energy. There are no sufficient differences in the energy consumption values for single flattened reed stalk cutting with different shaped knives. The average difference is approximately 2.4 kJ square m with knife edge angles 90 deg and 20 deg.
Afficher plus [+] Moins [-]Internal stresses of biomass compositions
2005
Nulle, I.(Latvia Univ. of Agriculture, Jelgava (Latvia))E-mail:Imants.Nulle@llu.lv | Kakitis, A.(Latvia Univ. of Agriculture, Jelgava (Latvia))
Relevant resources for biomass energy production are cereal straw residues and emergent vegetation from wetlands. This bulk herbaceous biomass is a material with low density. Density of briquetted straw and reed has been increased from 60 kg mE-3 to 1000 kg mE-3. The storage, dosage and mixing of biomass bulk materials before compacting are necessary, which requires working knowledge of the bulk properties of materials. The angle of repose of straw, reed and peat particles was investigated. It was stated that angle of repose of straw and reed varies between 45-55 degrees. The angle of repose of peat particles varies between 37-50 degrees. The stress ratio between horizontal and vertical stress is important for equipment design. This ratio was investigated for different size particles of straw, reed and peat. Stress ratio of straw particles varies between ~ 0.6-0.71.
Afficher plus [+] Moins [-]Steam water quality in the karst zone of Lithuania
2005
Rudzianskaite, A.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:aurelija@water.omnitel.net.
The paper gives the data about the mineralization process (sum of ions) and the amount of nutrient ions (nitrogen, phosphorus) contained in water of two streams (basin areas 1.63 square km and 2.02 square km) located in soils of different texture in the karst zone. As the study results have shown, higher amounts of DIN (dissolved inorganic nitrogen) were determined under the conditions of higher humus content in the soil (more humus (0.8-3.0%) was observed in glacial lacustrine soils), uneven runoff distribution (when its formation process is interrupted), and increasing DIN concentrations in silt. N-NO3 purification coefficient in stream water was higher when the stream was flowing via non-drained wood-covered area, also under the conditions of higher air temperatures. TP (total phosphorus) concentrations contained in stream water mostly depended on large amount of precipitation (especially in summer) as well as on phosphorus contained in silt: higher P2O5 concentrations contained in silt determined lower TP concentrations in water (determination coefficient of the relation r**2=0.24-0.30).
Afficher plus [+] Moins [-]Investigation and evaluation of the state of protective belts and inflow of erosion products into drainage channels
2005
Ragauskas, S.(Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.)E-mail:valentines@water.omnitel.net
As the result of the studies on the condition of protective belts of drainage channels (PB) have shown, due to improving maintained and mechanical damaged protective belts large amounts of erosion products contained in surface water inflows the channel bed. Disorderly condition of protective belts does not correspond to the requirements of environment protection. Mechanical damages are often related to unsustainable human activity in the adjacent zone of a drainage channel. According to the principles of soil occurrence in the channel bed, four groups of damages might be distinguished: soil entrance into the channel during the tillage of a protective belt; inflow of washout products from the basin; scours of protective belts and washout of turf flumes of surface water discharge. The most frequent damages enhancing the washout of flumes and inflow of erosion products are total or partial tillage of the protective belt of a drainage channel. From the point of view of erosion process, the inflow of erosion products from the basin is considered as the most dangerous damages, which is inevitable when the width of protective belt is insufficient, particularly in places with deep turf flumes arranged.
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