خيارات البحث
النتائج 41 - 50 من 87
Evaluation of art interventions for the public space in Latvia since the 1980'ies
2011
Alle, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The main aim of this paper was to investigate the development of art for the public space as a result of the historical impact through which the artworks have been evaluated. The context of social, ideological and economical changes is related. The author examined principal art practices in the public domain and discussed the main types of artworks created for the public space in Latvia in the period between 1980 and 2010. Seven art events were selected to analyze the main occurrence of historic periods as certain paradigms. Empirical and qualitative data collection methods were used to clarify the development of art for the public space in the Latvian landscape taking into account the historical point of view. According to the typology of artworks the following features were investigated: the aim, the location, the form and the size, and the function of artworks. The majority of art for the public space occurred in the city environment and the financial support of the project played an important role.
اظهر المزيد [+] اقل [-]Professional education teacher further education
2011
Aizsila, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Bierande, S., Latvia Univ. of Agriculture, Jelgava (Latvia)
The requirements for education, school and teachers become increasingly varied and complicated. The Latvian education system needs to be changed. The aim of the education reform is to establish a qualitative, accessible, competitive education system. The role of the teacher in studies changes with the economical and labour market changes. It determines new requirements and makes the knowledge, skills and competences of teachers change. To foster the development of teacher skills and acquisition of information, it is necessary to promote further education of teachers. The involvement of Latvia in the today’s global processes makes it necessary to substantially reconsider the aims and tasks of the education system – to ensure modernization of the education system and attain the introduction of new education content and methods. The article theoretically and empirically analyses and summarizes the further education experience of teachers at the Centre for Lifelong Education of the Latvia University of Agriculture in 2009/2010. The research target group - professional education teachers. The aim of the article is to justify teacher further education as development of professional and pedagogical competences in ensuring a modern and qualitative study process. The novelty of the research is related to the idea of the professional education reform and optimization of the network of professional schools.
اظهر المزيد [+] اقل [-]Winter oilseed rape (Brassica napus L.) autumn growth
2011
Balodis, O., Latvia Univ. of Agriculture, Jelgava (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
Lack of data about effect of meteorological conditions, sowing date, sowing rate, fungicide as growth regulator application and other agroecological factors on rape autumn growth is observed in Latvia. The aim of our research, started in autumn 2007 and continued up to autumn 2010 in Research and Study farm ''Vecauce'', was to investigate the influence of agroecological factors (sowing date, sowing rate and fungicide (as growth regulator in autumn)) application as well as meteorological conditions on autumn plant growth of two types of winter rape varieties. Winter rape biometrical parameters were estimated, and meteorological parameters (hydrothermal coefficient (HTC) and growing degree days (GDD)) were calculated. Four year results showed that winter oilseed rape seed germination was affected by precipitation and air temperature around the sowing time. Calculated GDD correlated with plant biometrical parameters during trial years. HTC showed moisture effect on rape emergence time. Sowing date was important factor which had strong and significant impact on biometrical parameters of rape plants in autumn. Earlier sowing date increased height of growth point, root neck diameter, plant and root mass, and main root length significantly for both cultivars in four trial years. Such agro-ecological factor as sowing rate (plant density) affected plant biometrical parameters only in some trial years. Plant weight was significantly influenced by sowing rate for both cultivars if sowing rates were equal. Other important parameter - height of growth point - was not significantly influenced by sowing rate for both cultivars when similar sowing rates were used in all years; exception was year 2009 for 'Californium'.
اظهر المزيد [+] اقل [-]Evaluation of some qualitative characteristics of new plum cultivars
2011
Gravite, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Kaufmane, E., Latvian State Inst. of Fruit-Growing, Dobele (Latvia) | Abolins, M., Latvia Univ. of Agriculture, Jelgava (Latvia)
A study was done at the Latvia State Institute of Fruit-Growing, evaluating new domestic plum (Primus domestica L.) selections, for which in 2008 -2010 some fruit quality characteristics were studied. In result of evaluation four new cultivars were selected from the breeding material and in 2010 handed in for cultivar registration in Latvia. Cultivar 'Ance' is early ripening one month before 'Victoria'. Cultivar 'Adele' is medium ripening one week before 'Victoria'. Fruits keep well in cool storage. Cultivar 'Sonora' is medium ripening one week after 'Victoria' and self-fertile. Fruits of this cultivar keep well in cool storage, too. Cultivar 'Lotte' is medium-late ripening two weeks later than 'Victoria', and is partially self-fertile. Average of three years, the highest soluble solids content was found for cultivar 'Adele' (13.28 Brix%), but cultivar 'Sonora' had the total content of acids (1.28 g 100 gE-1). Significant changes in flesh firmness were observed at different storage times for cultivars 'Ance' and 'Lotte'. Significant variations in the total content of acids were determined for 'Ance'. Whereas cultivar 'Sonora' demonstrated substantial fluctuations in soluble solids content. Correlations between firmness and soluble solids content were observed for cultivars 'Ance' (r=-0.731), 'Adele' (i=-0.436) and 'Sonora' (r=0.526). Cultivar 'Lotte' produced correlations between firmness and total content of acids (i=-0.536). Significance of interaction was determined within cultivars, years, and years x cultivars.
اظهر المزيد [+] اقل [-]Influence of rootstock on wintering and health status of plum cultivar 'Victoria'
2011
Dekena, D., Pure Horticultural Research Centre, Tukuma reg. (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Alsina, I., Pure Horticultural Research Centre, Tukuma reg. (Latvia);
The choice of rootstock is the main precondition for establishing of high yielding and sustainable plum orchards. Therefore influence of rootstock on the plum cultivars wintering in Latvia climatic conditions becomes more and more actual. Investigation was carried out with the aim to clarify influence of rootstock on the wintering and health status of plum cultivar 'Victoria'. Investigation was carried out at Pure Horticultural Research Centre during two different wintering seasons of 2008/2009 and 2009/2010, in the orchard planted in 2001. The winter of 2008/2009 was characteristic with sharp temperature fluctuations, but winter of 2009/2010 was snowy with stable low temperatures. Sixteen widely used rootstocks known in Europe were included. Plum general tree health status (scored by 1-5 points) and percentage of dead trees were evaluated. No statistically significant differences among rootstocks were established according to the evaluation of tree health status. Differences in wintering ability among rootstocks were stated between two years of investigation. Trees grafted on Brompton seedlings and St. Julien d' Orleans demonstrated the highest winter hardiness (4.3 points). No one dead tree was registered on these two rootstocks. Rootstock GF8/1 was the least suitable for Pure conditions - with general health status scored at 2.3 points after severe winter of 2009/2010, and only 25% of alive trees.
اظهر المزيد [+] اقل [-]Changes in serum immunoglobulins concentration of newborn calves
2011
Eihvalde, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Kairisa, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
The changes in the serum immunoglobulins concentration were investigated in newborn heifers from birth to 7 days of age. The mothers of calves were determined serum and colostrum immunoglobulins (Ig) concentration. The research was carried out at the Latvia University of Agriculture (LLU), in dairy farm ''Ligotnes'' of the Research and Study Farm ''Vecauce'', in a loose housing system with 530 cows, of which 430 were milking cows. The cows during the dry period were kept tethered in the farm. Eighteen heifers and their dams (Latvian Brown and Holstein breeds) which calved from 30 November 2010 to 23 January 2011 were used in this study. The calves' serum total immunoglobulin concentration at birth was 9.0 ±1.31 mg dLE-1 (or 0.09 mg mLE-1), and after 24 hours (h) it increased significantly to 4.3 mg dLE-1 (or 0.043 mg mLE-1), p is less than 0.05. The immunoglobulin G (IgG) concentration in calf serum after birth was 6.8 ±1.50 mg dLE-1 (or 0.068 mg mLE-1), and after 1 day and after 7 days it did not change significantly. The average Ig serum concentration in cows was 12.6 ± 1.36 mg dLE-1(or 0.126 mg mLE-1), and Ig concentration in colostrum was 18.5 ± 1.68 mg mLE-1. On average, close correlation (r=0.56) was found between cow blood serum IgM and colostrum IgM. Correlation between cow and calf IgG serum concentration proved to be weak (r=0.49).
اظهر المزيد [+] اقل [-]Effect of oral glycerol on the lactation performance of dairy cows in postpartum period
2011
Kass, M., Bio-Competence Centre of Healthy Dairy Products, Tartu (Estonia);Estonian Univ. of Life Sciences, Tartu (Estonia) | Ariko, T., Estonian Univ. of Life Sciences, Tartu (Estonia) | Ots, M., Bio-Competence Centre of Healthy Dairy Products, Tartu (Estonia);Estonian Univ. of Life Sciences, Tartu (Estonia) | Arney, D., Estonian Univ. of Life Sciences, Tartu (Estonia) | Kaert, O., Estonian Univ. of Life Sciences, Tartu (Estonia)
The treatment of ketosis with glycerol was first introduced in the 1950s. Currently, the availability of glycerol as a feed supplement for dairy cattle has increased due to the rapid expansion of the biodiesel industry. It has been suggested that glycerol can be used as a dietary glucose precursor for dairy cows in a similar way to propylene glycol. This study examined the effect of orally administrated crude glycerol on milk production and composition, and energy-status related blood metabolites of primiparous (n=4) and multiparous (n=4) Holstein dairy cows in the first three weeks of lactation. The treatment group cows were given an oral drench of 500 mL of crude glycerol once a day before the morning feeding. Long-term oral drenching of crude glycerol had no effect on dry matter intake (DMI), but there was a positive effect on milk yield. Most milk composition values were not affected by the treatment, but treatment groups had lower milk protein levels. Blood glucose and insulin concentrations were declined with glycerol administration.
اظهر المزيد [+] اقل [-]Relation between milk protein and urea content in different farms
2011
Ruska, D., Latvia Univ. of Agriculture, Jelgava (Latvia) | Jonkus, D., Latvia Univ. of Agriculture, Jelgava (Latvia)
Milk production and milk composition are of prime economic importance for farmers. It is well known in dairy management that the balanced feeding and holding technology is an important lever by which milk production and milk composition can be modified. The objectives of this work are to establish relation among milk protein and urea content in different farms. Four farms represent three cow breeds (Holstein Black and White, Latvian Brown, and cross breed XP). Individual cow milk samples (n=8400) were collected monthly from September 2009 to November 2010. Milk samples were analyzed for total protein, casein, fat, lactose, and urea content with instrumental infrared spectroscopy method. The average milk yield in farms was significantly different (from 26.8 to 16.0 kg per control day), and average protein content varied from 3.32 g kgE-1 to 3.62 g kgE-1. The urea content in cow milk was between 21.3 to 42.6 mg 100 mLE-1. The average protein content was higher and significantly (p is less than 0.05) different in first yield level (up to 15 kg) for all farms. Overall, in different farm and milk yield levels correlation between protein and urea was low or very low. In the farm C, average urea content ranged between 30.0 and 60.0 mg 100 mLE-1, which indicated problems in feeding or management in the farm. It was established that milk productivity traits significantly (p is less than 0.05) varied in farms with different dairy cow holding and feeding technologies and milk protein and urea content significantly (p is less than 0.05) varied for cows with different milk yield per day.
اظهر المزيد [+] اقل [-]Detection of volatile compounds during wheat dough fermentation
2011
Sabovics, M., Latvia Univ. of Agriculture, Jelgava (Latvia) | Straumite, E, Latvia Univ. of Agriculture, Jelgava (Latvia) | Galoburda, R., Latvia Univ. of Agriculture, Jelgava (Latvia)
Taste, smell and the flavour are the most important attributes determining the quality of bread or baked cereal products in general. Bread flavour is composed of hundreds of volatile and non-volatile compounds, i.e. many alcohols, ketones, aldehydes, acids, esters and other compounds. Many researchers have been studying volatile compounds in different breads worldwide, but in Latvia only few studies are conducted on volatile compounds in bread and its production stages. The aim of this research was to analyse the composition of volatile compounds during wheat dough fermentation. Experiments were done in 2011 and carried out in the Laboratory of Bread Technology and Laboratory of Packing Material Investigations at the Department of Food Technology in the Latvia University of Agriculture. An investigation of volatile compounds was done using solid-phase microextraction (SPME) and gas-chromatography mass-spectrometry (GC-MS). Volatile compounds were analyzed on the 10th, 20th and 30th minutes of wheat dough fermentation. In a fermentation process of wheat dough totally 15 volatile compounds were detected. Eight of them were alcohols, two aldehydes, two ketones, one ester, one acid and one terpene. Three volatile compounds – 1-octanol, caryophyllene and acetophenone, were detected in the dough samples only after 30 minutes of fermentation – those were not detected at the earlier stages of fermentation. The peak areas of 11 volatile compounds increased, but peak area of one volatile compound decreased along the fermentation time. The study proved that solid-phase microextraction can be used for detection of volatile compounds in wheat dough fermentation process.
اظهر المزيد [+] اقل [-]Behaviour of inoculated wild L. monocytogenes in sliced vacuum-packed cold smoked pork
2011
Silins, I., Latvia Univ. of Agriculture, Jelgava (Latvia);Food and Veterinary Service, Jelgava (Latvia). Dienvidzemgale Branch | Liepins, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
The non-spore forming gram-positive bacterium Listeria monocytogenes is a food pathogen bacterium and a causative agent of listeriosis. The aim of the study was to determine the survival limits of L. monocytogenes inoculated in manufactured vacuum-packed cold smoked pork depending on shelf time, supported by water activity (aw) and pH values. Enumeration of L. monocytogenes colony forming units per gram (cfu gE-1) was done according to ISO standard. Water activity (aw) and pH values in pork samples were more or less constant and supported L. monocytogenes growth. The behaviour of L. monocytogenes in cold-smoked sliced pork by shelf time, when environmental factors changed minimally and supported growth, largely depended on the initial contamination level. A lag-phase of bacterial growing process before exponential growth rate of inoculated L. monocytogenes depended on initial cell concentration and had 10 days step level if storage temperature was approximately 5 deg C. A significant Pearson’s correlation (p is less than 0.01) was established between the microbiological test values of L. monocytogenes count changes in sliced and packed cold-smoked pork during storage time of 60 days. The main parameter which maintained negative polynomial growth rate of L. monocytogenes in cold-smoked pork was the decrease of live cell concentration in samples below lg 2.0. The experiments were done at the Faculty of Veterinary Medicine of Latvia University of Agriculture and at a sausage manufacturer’s laboratory.
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