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Результаты 131-140 из 2,098
Phosphorus removal in constructed wetlands of subsurface and surface flow
2008
Gasiunas, V., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst. | Strusevicius, Z., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
Constructed wetland (CW) treatment systems are engineered systems designed to treat wastewater with the usage of the same processes that occur in natural wetlands. The full-scale investigations of free water flow surface filters (FWF), subsurface flow filters, including filters of vertical flow (SVF) and horizontal flow (SHF) were carried out in Lithuania. The investigations’ database collected within the study period of 1995-2007 was used for the estimation of phosphorus removal efficiency of different constructed wetlands. It was established that phosphorus removal efficiency depends on construction of filters and the load according to total phosphorus for the area unit of filter surface. Subsurface flow filters are distinguished by better phosphorus removal. At the same load of all filters, i.e., total phosphorus of 0.3 g mE-2 dE-1, the removal efficiency of subsurface flow horizontal, vertical, and free water flow filters reaches 53.0, 46.5 and 28.0%, respectively. The wastewater contains phosphorus in mineral and organic forms. Due to the aerobic conditions in filters of vertical flow, the amount of organic phosphorus removed by SVF is 3 times greater than in horizontal filters. Organic phosphorus in wastewater before the treatment by vertical filters constituted 27% of total P, and after the treatment 21%. In wastewater treated by horizontal filters this ratio was 21% and 31%, respectively.
Показать больше [+] Меньше [-]Effects of topical and systemic atropine [sulphate] on intraocular pressure and pupil diameter in dog's eye
2008
Kovalcuka, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The objective of this study was to determine the effects of topical 1% atropine sulphate and systemic atropine sulphate on intraocular pressure (IOP) and horizontal pupil diameter (HPD) in dog’s eyes. Ten adult dogs for each treatment were used in this study. Dogs of different age, breed and sex were examined clinically and ophthalmologicaly. All animals were clinically and ophthalmologically healthy. One drop of topical 1% atropine sulphate was used in ten dogs unilaterally, with the contralateral eye acting as a control. IOP and HPD were measured every 5 minutes. In ten dogs systemic atropine sulphate were used intramuscularly (IM) with IOP and HPD measured every 5 minutes. In both study phases IOP and HPD were measured over a total duration of 60 minutes. After unilateral application of topical atropine, IOP increased significantly in the treated eye. A maximum average IOP of 20.3 mmHg in the treated eye was observed 20 minutes after treatment. Maximal pupil dilatation in the treated eye was observed 35 min after treatment. Measurements made after systemic atropine showed an IOP increase in both eyes, showing maximum average IOP increase 25 minutes post-treatment. Maximum average values of HPD were obtained 25 minutes after treatment. The HPD started to decrease 30 minutes after treatment but it was still significantly higher than before treatment (P is less than 0.05). Because of atropine sulphate’s ability to cause significant increase in IOP, it should not be used for diagnosis and treatment of glaucomatous eyes.
Показать больше [+] Меньше [-]Location of helicobacters in the gastric mucosa of domestic dogs (Canis familiaris)
2008
Berzina, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Birgele, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
This study was done to evaluate the prevalence and colonization density of helicobacters in the gastric mucosa of domestic dogs (Canis familiaris). Mucosal samples were taken from several places of cardiac, fundic and pyloric gland region of the stomach to detect helicobacters with urease test, brush cytology, and light histological examination. Fourteen dogs of fifteen sampled animals showed positive urease test and the presence of tightly spiraled helicobacters. Positive urease test was observed in 80.4% of all examined samples. Helicobacters were detected in 82.7% of all examined samples by brush cytology and 80.8% of all examined samples by histological examination. Compared to gastric regions, in all employed detection methods have been showed significantly higher prevalence of helicobacters in cardiac and fundic gland region than in the less effected pyloric gland region of the stomach. Histological examination showed the location and colonization density of the bacteria at the superficial epithelium, gastric pits, and deep glandular epithelium of the gastric mucosa in different regions of the stomach. Colonization density of bacteria was evaluated in 4 groups: as absent, mild, moderate, and severe colonization density of helicobacters. Occurrence of helicobacters in the cardiac and fundic gland region showed mild and moderate colonization density of helicobacters at the superficial epithelium and at the gastric pits of the gastric mucosa. Colonization density of spiral-shaped bacteria between the deep glandular epithelium was more pronounced in the pyloric gland region than in the cardiac and fundic gland regions of the gastric mucosa in the domestic dogs.
Показать больше [+] Меньше [-]The evaluation of sensory properties of Latvian semi-hard cheeses
2008
Novikova, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Strautniece, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Cirovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Annual judging of dairy products including sensory evaluation of local cheese-maker' cheeses proved that the quality of Latvian classical cheeses is various. In fact, in last three competitions three different manufacturers gained the first place in category of Krievijas and Holandes types' cheeses. It indicates instability of Latvian cheese quality. Two types of semi-hard cheeses (Krievijas and Holandes) were selected for testing the quality of Latvian semi-hard cheeses in the beginning of 2008. Krievijas type cheese was selected from three different manufacturers, but Holandes type cheese - from five different manufacturers. Sensory properties such as flavour, structure and colour were measured using line scale method. Statistical analysis of obtained data showed differences between such assessed properties as colour (yellowness), texture (firmness), holes, flavour (acidity and bitterness) in Krievijas type cheese, and colour (yellowness), texture (firmness), flavour (saltiness) in Holandes type cheese.
Показать больше [+] Меньше [-]Lactic acid bacteria in rye sourdough from crude and peeled rye flour
2008
Kozlinskis, E., Latvia Univ. of Agriculture, Jelgava (Latvia) | Skudra, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Klava, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kunkulberga, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
In Latvia the spontaneous sourdough is used in traditional rye bread baking whose microflora is determined in flour and in microorganism cultures presented in external environment. Almost all spontaneous sourdough cultures, especially those that have been maintained for a long time, contain both lactic acid bacteria (LAB) and yeasts. The main purpose of the current research was to analyze growth dynamics of LAB in spontaneous rye flour sourdough and to isolate some of its representatives. Experiments were carried out in the Department of Food Technology of the Faculty of Food Technology of Latvia University of Agriculture in January and February 2008. Considering differences in constituents, two types of flour were used in the research - peeled and crude rye flour. There were three stages of spontaneous sourdough preparation in 72 hours totally; the renewal of sourdough was realized each 24 hours. The dynamics of LAB plate count in every stage of fermentation was investigated as well as changes of pH was observed using standard methods. The results of experiments show substantial increase in amount of LAB in both sourdoughs, particularly in sourdough from peeled flour, reaching 6.06 log10 cfu mlE-1. A significant decrease of pH value from pH 6.7 to pH 3.8 during fermentation process was observed. As a result, the sourdough from peeled flour had desirable properties for preparation of sourdough starter. LAB cultures isolated and identified from current sourdoughs using API tests: Lactobacillus brevis and Lactobacillus fermentum are also typical members of sourdoughs found in other countries.
Показать больше [+] Меньше [-]The application of organic trace minerals in beef cattle nutrition
2008
Bula, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ositis, U., Latvia Univ. of Agriculture, Jelgava (Latvia)
Understanding the efficacy of organic trace minerals has been increasingly important over the past few years as a result of increased customer awareness of their benefits and the increase in the number of commercial products available to the customer. Organically bound trace minerals of interest in animal nutrition specifically include iron, zinc, manganese, copper, cobalt, and selenium. These elements have been shown to improve reproductive efficiency as measured by conception rate, alleviated calving, and reduced placenta expulsion rate. Additional benefits include improved growth performance of calves. The field trials in the period of 2005 – 2007 with Charolais breed beef cattle cows and calves verified efficacy of the premix PROTRACE G containing Fe, Zn, Cu, Mn, and Co chelates, Se-amino acid (selenomethionine), potassium iodide, and vitamins A, D3 and E. Average calving rate of experimental group cows fed diet with added premix was 20 – 30 min, placenta expulsion time - 28 – 31 min, but in control group fed only basal diet - 2 h 21 min and 1 h 30 min – 2 h 09 min (p is less than 0.05) respectively. Live weight gain of calves and heifers of the experimental group was on 35 – 39% higher (p is less than 0.05) than that in the control group.
Показать больше [+] Меньше [-]Investigation of polyploidy in the breeding of lilies (Lilium spp.)
2008
Balode, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
Some of best varieties of plants, especially ornamentals and fruits, were polyploid. Polyploids have larger flowers and stems than diploids. In the production of polyploid forms, different types of crosses were made. In present study a cross of diploid (2n = 2x = 24) and tetraploid (4n = 4x = 48) varieties resulted in the production of highly viable seeds 89.3% on average, but a cross of tetraploids and diploids – of 39.5% on average, with fluctuating results between cross combinations. Treating seeds and bulb scales with colchicine solutions can change chromosome number of 9 varieties. These results demonstrated that optimal concentration of colchicine was 1 g kgE-1 for chromosome doubling of seeds. A high concentration (2 g kgE-1) showed phytotoxicity that is detrimental for plant regeneration. The scales of bulbs treated with 1 g kgE-1 colchicine have resulted in the production of lily polyploid forms. The polyploid plants regenerated after pre-treatment by colchicine may be selected in early stage by phenotype of young bulblets. Broad, fleshy bulb scales setting right angle to growth axis were characteristic for regenerated tetraploids. The produced polyploid plants, in comparison with diploids, had a larger diameter of the flower (+2 up to 2.5 cm), more extended plant height (+10 up to 20 cm), increased flower count (+2) and was coming into bloom 4-10 days later than diploids of the same variety.
Показать больше [+] Меньше [-]Development of economic basis of meat production in Latvian agriculture
2008
Romanova, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
In this study the development of meat sector in terms of livestock population, production, farm size and reproductive material, which forms economic basis for effective meat production was analysed. The aim of the study was to investigate main tendencies of meat production sector and development of economic basis in Latvian agriculture. To achieve the set aim following objectives were defined: 1) to analyse concentration and specialization processes of pig breeding farms; 2) to describe restructuring processes of reproductive pig breeding; 3) to investigate restructuring processes of farms producing beef; 4) to characterize concentration and integration processes in poultry production. The study was based on annual statistical data and statistical bulletins covering results of the Farm Structure Survey from 2001 to 2006, scientific publications, special literature and reports of international organizations. To carry out the research adequate research methods were used. The results of this study showed that meat industry has structurally changed in recent years, where the structural change can be defined as the change in the number and size of farms in pig, cattle and poultry sectors. The results also suggested that meat production sector in Latvia has become more intensive, concentrating meat production in large and specialized farms, where this tendency can stimulate the increase of meat production. Therefore, knowledge of the current tendencies and strategies of pig, cattle and poultry sectors is a necessary precondition for the development of the meat sector.
Показать больше [+] Меньше [-]Transaction costs of agri-environmental policy measures: the extreme bounds analysis applied to permanent graslands
2008
Nilsson, F.O.L., Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Economics
It has been shown in previous studies that transaction costs (TC) of agri-environmental policy measures often are very large both in absolute terms and as a share of payments. As agri-environmental policy measures make up an increasingly large share of agricultural policies, not least within the European Union, it is becoming ever more important to improve the knowledge about the factors determining the level of transaction costs. This paper investigates the TC determinants of one Swedish agri-environmental policy measure. More specifically, it aims to investigate if the level of TC is attributable to economic factors, such as pasture density and distances, or if political factors, such as lobby groups and political majorities at the county level, influence the costs. To evaluate if the results are robust with respect to alterations in model specifications, a version of the extreme bounds analysis is applied. Although initial results indicate that political parties influence the level of transaction costs, the extreme bounds analysis reveals that those results are fragile. It shows that five of the economic variables are robust with respect to model specifications, but none of the political variables is.
Показать больше [+] Меньше [-]Primary energy resource consumption
2008
Vanags, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
Primary energy resource consumption in the world is surveyed in the work and oil yield, production and consumption evaluated on the world level, also showing its density in the view of several states. Oil reserves are evaluated and the states with biggest oil reserves stated. The research proves consumption of primary energy oil in the world is increasing continuously. There are primary energy resources to be acquired in Latvia evaluated and primary energy resources in means of final consumption divided between types of energy estimated.
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