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Guideline for development of landscape spatial composition of the residential areas
2010
Ile, U., Latvia Univ. of Agriculture, Jelgava (Latvia)
The development of the multi-storey residential areas in the Baltic Sea region shows an inequality that changes the spatial environment of the territory. The major part of the city territory is occupied by the multistorey residential area that reveals multiple problems of the spatial environment. Therefore, it is necessary to resolve these problems by building new more multi-functional zones in the multi-storey residential areas that would further ensure the sustainable development of the spatial environment. To find the relevant data and material, a scheme of questions for analysis was developed. The scheme reflects all the necessary aspects for the analysis of the landscape composition in multi-storey residential areas. The analysis from the theoretical aspect with the usage of empirical methods determined the current state of the multi-storey residential areas in the Baltic Sea region. The paper presents the study of historical development and the causes of changes, as well as the current state and potential future development of the landscape composition of the multi-storey residential areas. It also reflects the development framework of the landscape composition. The multi-storey residential area that carries a great load of the multi-functional areas, needs an improvement, a renovation and needs to be reconstructed and developed according to all the mentioned characteristics of the spatial environment.
Afficher plus [+] Moins [-][Implementation of Moodle in the information technology system architecture of Latvia University of Agriculture]
2010
Paulins, N., Latvia Univ. of Agriculture, Jelgava (Latvia)
One of key elements when implementing e-learning system is integration in already existing system. System implementation begins with a planning process and ends with installation and maintenance. First of all, it is necessary to determine project team and set responsibilities, collect all information about current situation and possible changes. Latvia University of Agriculture has just started to plan implementation of Moodle system, as its e-learning environment. This article attempts to provide answers on some implementation questions during the system development lifecycle process.
Afficher plus [+] Moins [-]Traits influencing spring barley competitiveness against weeds under organic and conventional conditions
2010
Kokare, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Legzdina, L., State Priekuli Inst. of Field Crops Breeding, Cesis reg. (Latvia)
The aim of studies was to identify how different morphological and biological characteristics influence spring barley (Hordeum vulgare L.) competitiveness against weeds in various organic and conventional farming locations. Do those traits have an influence on the yield and in which growing conditions the selection of genotypes for organic farming should be done? The plant traits related to competitiveness against weeds at the beginning of the vegetation period are important in breeding for organic agriculture. Ten different varieties were included in trials for three years in two organic and two conventional environments. The included varieties were divided in four groups with respect to time of release and adaptation to growing environments: old extensive varieties and landraces for low input agriculture, medium old varieties with good adaptation to unfavourable conditions, modern varieties for low input, and modern varieties for high input conditions. Results showed that such traits as productive tillering ability, development speed and plant height at the beginning of stem elongation stage provide good soil shading. The most of traits were negatively related to the grain yield. Selection of genotypes for traits which influence spring barley competitiveness against weeds, such as a growth habit in the tillering stage, development speed in tillering stage, plant height at the beginning of stem elongation, length of flag leaf and the width of flag leaf, and the plant height before harvest, may take place in conventional conditions as well as in organic conditions.
Afficher plus [+] Moins [-]Effect of different plant production methods on yield and quality of winter wheat 'Portal' in 2009
2010
Tein, B., Estonian Univ. of Life Sciences, Tartu (Estonia) | Eremeev, V., Estonian Univ. of Life Sciences, Tartu (Estonia) | Keres, I., Estonian Univ. of Life Sciences, Tartu (Estonia) | Selge, A., Estonian Univ. of Life Sciences, Tartu (Estonia) | Luik, A., Estonian Univ. of Life Sciences, Tartu (Estonia)
The yield and quality (volume weight, 1000 kernel weight, protein content, falling number, gluten content, gluten index, gluten content in dry matter) of winter wheat was studied in variety 'Portal'. The wheat was part of the five-year crop rotation experiment where red clover (Trifolium pratense L.), winter wheat (Triticum aestivum L.), peas (Pisum sativum L.), potato (Solanum tuberosum L.) and barley (Hordeum vulgare L.) were following each other. There were two production variants which followed the crop rotation. In one variant mineral fertilizers and pesticides were used, and the other variant was conversion to organic without any synthetic agrochemicals. In mineral fertilizing variant, on the background of P25 and K95 kg haE-1 the N amount varied from 0 to 150 kg haE-1 and herbicide Mustang (preparation norm 0.5 L haE-1, active substance florasulam, 6.25 g LE-1; 2.4-D, 300 g LE-1), insecticide Fastac 50 (preparation norm 0.2 L haE-1, active substance 50 g LE-1 alphacypermethrin) fungicide Falcon EC 460 (preparation norm 0.4 L haE-1, active substances 167 g tebuconazole, 250 g spiroxamine, 43 g triadimenol) and growth regulator Moddus (preparation norm 0.4 L haE-1, active substance 250 g LE-1 trinexapac-ethyl) were used. In conversion to organic the winter wheat grains which followed the red clovers after effect had higher volume weight, 1000 kernel weight and gluten index compared to the variants where mineral fertilizers were used. The yield, protein content, falling number and gluten content in dry matter increased with increase of the amount of mineral N. The wet gluten content was significantly higher compared to the other variants where the N amount was 50 kg haE-1.
Afficher plus [+] Moins [-]Preliminary observations of phenology development, yield and yield quality of some highbush blueberry cultivars in Latvia
2010
Sterne, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Liepniece, M., Latvia Univ. of Agriculture, Jelgava (Latvia)
Cultivars of northern highbush blueberries (Vaccinium corymbosum L.) are the most suitable for areas with long, cold winter, because they require the greatest number of winter chilling hours. The blueberries are excellent sources of phytochemicals that are believed to have a significant biological activity. The experiment was done at the Institute of Agrobiotechnology, Latvia University of Agriculture, Jelgava, in the year 2009. The aim of the experiment was to evaluate phenological development of 9 highbush blueberry cultivars, their yield, fruit weight and biochemical composition: total anthocyanins, total phenols, ascorbic acid, titratable acids, and soluble solids. The obtained data showed correlation between duration of flowering and fruit ripening; between harvest and end of vegetation period of the highbush blueberry. The phenological development was dependent not only on cultivars, but also on the effective air temperature (above + 5 deg C). The research results allow assessing the phenology development of blueberry cultivars and predicting the fruit ripening time in conditions of Latvia. The most productive cultivars were 'Patriot' and 'Northland' The biggest single berry weight presented the cultivars 'Chippewa' and 'Bluejay'. The cultivar 'Jersey' had the highest content of titrable acid, anthocyanins, and ascorbic acid. The highest phenol content was detected in highbush blueberry cultivars 'Spartan' and 'Bluecrop'.
Afficher plus [+] Moins [-]Phenotipic analysis of hybrids and their parents in Lilium spp. breeding
2010
Balode, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The lily (Lilium L.), a vegetative propagated perennial crop, is one of the economically most important flower bulb plants. It is cultivated worldwide as a cut flower, garden plant and pot plant. Lilies, 'the aristocrats of the garden', are very popular for their elegant flowers and stately habit, and offer the gardener an enormous range of colours, forms, and fragrances. The aim of this research was to evaluate the parent plants with the hybrids according to their morphological characteristics: plant height, flower diameter and inflorescence: number of flowers. In a trial, fourteen cross combinations were analyzed in 2006 – 2007. The evaluation was conducted in a lily breeding and growing farm 'Puķulejas', located in Saulkrasti, region of Riga, Latvia. The results showed that, if there were no significant differences in plant height between the parent plants, the hybrids were shorter than their parents. Male parents with short stems produced hybrids with shorter stems. Parental selections of medium and large number of flowers produced hybrids with comparatively large numbers of flowers on a stem, but if parents of different number of flowers were selected, in hybrids the smaller count dominated or prevailed.
Afficher plus [+] Moins [-]The influence of biomass type on quantitative and qualitative indicators of biogas
2010
Straume, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
The utilization of traditional fossil fuels (oil, gas) as primary energy resources causes a destabilization of the eco-environmental situation in the world. Latvia has to significantly decrease energy imports from its neighbouring countries. This can be achieved by using high-quality local primary renewable energy sources. One of the solutions is to utilize anaerobic fermentation for biogas production. This process can be ensured by utilizing manure, food waste as well as energy biomass - wood, grass and maize. Biogas is utilized as a primary energy source in a cogeneration plant which is a combined cycle plant for electricity and heat power production. Microcogeneration plant for farming household needs would ensure an independent power supply, in case the overall electrical network is in a state of emergency. In order to ensure optimal biogas yield, which, in turn, would ensure a stable operation of the microcogeneration plant, it is important to know the parameters and quality of the biomass that have been filled in bioreactor. This research deals with the influence of the linkage biomass type on the qualitative and quantitative indicators of biogas. As a result, it has been found that biomass type affected the methane percentage in biogas greatly. The methane content of biogas independent with biomass type was diminished from 65% (galega) to 44.5% (fresh sawdust), but biogas yield decreased from 0.627 m**3 kgVSd E-1 (galega) to 0.185 m**3 kgVSd E-1 (fresh sawdust).
Afficher plus [+] Moins [-]Diversity of Lactobacillus spp. in Krievijas cheese
2010
Mikelsone, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ciprovica, I., Latvia Univ. of Agriculture, Jelgava (Latvia)
Dairy ecosystems have been developing in thousands of years giving us wonderful collection of different types of cheese varieties. On the other hand, modern technology provokes the loss of variability (Adamberg et al., 2007). The only way to keep biological processes under control is to study physiology of microorganisms, and relationships between them systematically, especially non-starter lactic acid bacteria (NSLAB). The number of non-starter lactic acid bacteria increases during cheese ripening and may constitute a dominant population in the mature cheese. The NSLAB diversity, their metabolism and interactions with starter bacteria have an effect on the ripening process of the cheese. The aim of the present study was to investigate the diversity of Lactobacillus spp. during ripening of Krievijas cheese. The diversity of different profiles varied among the cheese samples matured at different temperatures, and the results indicated a correlation between NSLAB species and aroma development (Miķelsone et al., 2009). A higher metabolism of Lactobacillus curvatus at 12 deg C leads to faster depletion of nutrients and approaching the last two phases of microorganism growth curve. However, in each of the cheeses, the microflora had a tendency to be dominated by one Lactobacillus profile at the end of maturation.
Afficher plus [+] Moins [-]Dynamics of sugars composition in berries
2010
Boca, S., Latvia Univ. of Agriculture, Jelgava (Latvia) | Skrupskis, I.A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dimins, F., Latvia Univ. of Agriculture, Jelgava (Latvia) | Krasnova, I., Latvian State Inst. of Fruit-Growing, Dobele (Latvia)
The major sugars in six cultivars grown in Latvia are analysed. The content of glucose, fructose and sucrose in strawberry, blackcurrant and redcurrant berries was determined by applying the method of high performance liquid chromatography (HPLC). By using the obtained calibration curves, concentrations of diverse sugars were found in the analyzed samples. Fructose or fruit-sugar, the same as glucose, is mainly the source of energy in the human body though it is decomposed faster and easier than glucose. In all the researched berry cultivars, the amount of fructose was the largest, particularly in blackcurrants. Six strawberry, black- and redcurrant cultivars were evaluated as raw materials for industrial production. The investigation involved chemical and sensory analyses of fresh berries. The results indicate that pH and sugars of fresh berries influence their quality. Furthermore, high level of sugar adversely affects taste stability. Taste degradation in berries is parallel to flavour deterioration. It is concluded that the main emphasis should be given to the properties of fresh berries.
Afficher plus [+] Moins [-]Changes in physically-chemical and microbiological parameters of Latvian wild cranberries during convective drying
2010
Dorofejeva, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rakcejeva, T., Latvia Univ. of Agriculture, Jelgava (Latvia) | Skudra, L., Latvia Univ. of Agriculture, Jelgava (Latvia) | Dimins, F., Latvia Univ. of Agriculture, Jelgava (Latvia | Kviesis, J., Latvian State Inst. of Fruit-Growing, Dobele (Latvia)
The research focuses on the study of physically-chemical and microbiological parameter changes in Latvian wild cranberries during convective drying. The research was accomplished on fresh Latvian wild cranberries. The following quality parameters were controlled during the experiments: moisture content (oven-dry method), content of vitamin C (LVS EN 14130:2003), content of polyphenol (HPLC), preparation of samples for microbiological testing (LVS EN ISO 7218:2007), enumeration of yeasts and moulds (ISO 21527-2:2008(E)), counting of lactic acid bacteria (LVS ISO 13721:1995), and total plate count (LVS EN ISO 4833:2003A). The research detected the following optimal convective drying parameters of wild cranberries: temperature – +50±1 deg C and drying time – 20.3 hours. The moisture content of dried berries equalled to 9.0±0.1%. The content of vitamin C decreased 1.9 times in wild cranberries dried at the temperature of +50±1 deg C compared with the content of vitamin C in non-dried cranberries and was 13.05 mg 100 gE-1 in dry matter. The results of current experiments show, that the content of such polyphenols as gallic, caffeic, and epicatechin acids decreased 9.70, 9.90, and 11.68 times, respectively, during the treatment at temperatures up to +50±1 deg C compared with the initial content of these compounds in non-dried berries. The drying temperature substantially influences the microflora development in cranberries. It is possible to decrease significantly the content of LAB, mould, and fungi in berries provided the drying temperature of the wild cranberries does not exceed +50±1 deg C, thus prolonging the ready product shelf-life.
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