Corticosteroid therapy is often used on dogs (Canis lupus familiaris) to treat different kinds of diseases. One of the most common complications of corticosteroid use is steroid hepatopathy, a specific pathology only in dogs. The objective of this study was to determine whether and how significant the liver functional changes after one administration of different kinds of corticosteroids in standard dosages are. The study took place in private veterinary clinics in Riga, Latvia, during 2013 - 2014, with the permission of dogs’ owners. Twenty animals, which received corticosteroids due to present diagnosis, were divided into four groups. To reach the aim such corticosteroids as dexamethasone sodium phosphate, prednisolone acetate, methylprednisolone acetate and hydrocortisone aceponate were used in standard dosage one time to these dogs, respectively. Then, such blood serum enzymes as alaninaminotransferase (ALAT) and alkaline phosphatase (AP) were determined 24, 48 and 96 hours after the use of corticosteroids. It was discovered that the only one administration of dexamethasone sodium phosphate and methylprednisolone acetate in standard dosage can significantly increase (p is less than 0.05) ALAT and AP mean values in dogs. The corticosteroid prednisolone acetate was used once in standard dosage and hydrocortisone aceponate spray was used once and did not statistically significantly (p is greater than 0.05) change the values of alaninaminotransferase (ALAT) and alkaline phosphatase (AP) in dogs’ blood serum during this study.

Morphological parameters and their changes common for artificially reared one year old sea trout were examined from January to May the year 2013 to determine whether these parameters indicated the smoltification in one year old sea trout and whether these fish achieved smolts stage. Fish were reared in flow-through and recirculation systems in hatcheries based on three different rivers (Brasla, Daugava, Venta basin). Sea trout were examined in the Latvia University of Agriculture, Faculty of Veterinary Medicine, Institute of Food and Environmental Hygiene and in the Institute of Food Safety, Animal Health and Environment BIOR, Laboratory of Aquaculture and Fish Pathology. To appreciate fish growth stage condition index, hepatosomatic index, spleen index was calculated and silvering level was evaluated. The fish condition index decreased in all hatcheries and flow-through and recirculation rearing systems from January to April and increased in May. Spleen index was the most stable parameter and did not change a lot showing that fish did not have migratory stress in April and May. Silvering level increased from January to April but suddenly the increase became slower in May without reaching the top level. These results made us to consider that one year old sea trout parrs released in May 2013 probably did not become smolts before release and they had to stay in river for one additional year until reaching pronounced smolt stage.

Land consolidations in Slovakia are regarded as an instrument for solution of ownership fragmentation in accordance to rural development. In the introduction of this paper, we describe problems in Slovakia associated with the ownership fragmentation. Country, rural areas were significantly influenced by the period of collectivization. The benefits of land consolidation project are shown in a case study area for Kanianka cadastre. We compare ownership relations before and after the land consolidation. Statistical values as number of resolved ownerships by LC, number of plots and average size of plots are shown. New infrastructure, water management and ecological elements are discussed. In conclusion, we give the reason why activities related to land consolidation in Slovakia stagnates despite positive response.

In conditions where induction motors are frequently started, overloaded and used in high inertia applications with long starting times, supplied from frequency converter, a temperature protection system are more reliable to protect induction motor stator winding against thermal overloads. There are different types of temperature protections - thermostat, PTC thermistor, resistance temperature detector (RTD) and thermocouples, so it is important to know the properties of each type to choose an adequate protection system. Analyses of temperature sensor properties and their advantages and disadvantages show, that PTC thermistor is a cost-effective temperature protection solution, but for medium and high voltage induction motor protection RTD are commonly used. A virtual model has been represented to simulate the temperature sensor thermal time constant under different thermal conductivity and thickness of winding magnet wire insulation.

Information and communication technology combined with multimedia and networking has enabled development of e-learning. E-learning opportunities expand access to education, without the learner’s social, economic and geographical barriers. The main question in this situation has to take into account the quality of e-learning materials. The aim of this research was to explore the definition of the quality and scientific research literature on e-learning quality, and identify the quality influencing factors. This article looks at quality standards and summarizes the existing literature on the quality aspects of electronic materials. During the research was analyzed the literature of the last 13 years. Findings showed that the quality evaluation model covers a wide scale — from one e-course to e-learning system implementation quality aspects. The quality of electronic learning material can be measured by technical, pedagogy and content criteria. The technical quality of the e-material (text, picture, video, sound recording, visual presentation, multimedia, etc.) is influenced by many factors and specifying for each type. The research should be continued to indicate the quality criteria for each type of e-materials including the degree of importance.

One of the most challenging issues in forest inventory based on remote sensing data is identification of tree species. Hyperspectral remote sensing data provides information which considerably facilitates tree species recognition. The objective of the research is to evaluate different hyperspectral data analysis methods to classify tree species in Latvian forest conditions. The study site is a forest in the central part of Latvia, Jelgava district (56º39’ N, 23º47’ E). The area consists of a mixed coniferous and deciduous forest. During research 598 trees were analyzed in 70 sample plots. Remote sensing data are 64 hyperspectral bands in the 400 - 970 nm spectral range. Two different classification techniques: linear discriminant analysis (LDA) and artificial neural networks (ANNs) were used. In LDA species classification was done by stepwise and using principal components of hyperspectral bands. In stepwise LDA 18 hyperspectral bands were used. LDA using principal components and ANNs used all 64 hyperspectral bands. The best results show stepwise LDA where 82.4% of the data were correctly classified. Scots pine was classified 94.8%, Norway spruce 83.5%, Silver birch 77%, European aspen 71.4% and Black alder 56.3%. Classification with ANN’s best results showed for Scots pine, Norway spruce and Silver birch – respectively 81%, 84%, 86%. With LDA using principal components Scots pine’s classification showed best results with 85.1% correctly classified trees.

The objective of this study is to elaborate the mathematical model describing the bark proportion (BP) in stems of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies [L.] Karst), silver birch (Betula pendula Roth.) and aspen (Populus tremula L.), as well as to analyze the vertical variation of the BP for the aforementioned species. The study material consists of data of 372 sample trees sampled in three regions of Latvia – Western (Kurzeme), Eastern (Latgale) and North-eastern (Vidzeme) during the years 2011 – 2014. The BP for each tree was calculated as a difference between the under-bark and over-bark stem volume. In this study, we compared the performance of three power regression models in predicting of BP using breast height diameter (DBH), tree height (H) and total volume (TV) as independent variables. The best fit to data was achieved by using tree height for the prediction of BP. Our results confirm that the highest proportion of the bark is at the upper part of the stem (relative height 95%) for all trees species. Pine stems have a lower BP of up to 30% relative height comparing to other species, while the spruce has the lowest bark percentage at the stem base relative to other tested species There were no significant differences found in BP among the stands from different regions for all studied species, indicating no need for derivation of separate equations for each region and ascertaining the possibility of use of the average BP values for the whole country.

The regeneration of European hornbeam (Carpinus betulus L.) has been assessed in the National Gene Reserve Forest near Lukne in the south-western part of Latvia, which is the northernmost point of hornbeam distribution in Europe. In the studied stand, six sampling plots and four transects were established to assess stand structure and the effect of irradiation parameters on stand regeneration. Successful regeneration of hornbeam was shown by its presence in all height and diameter classes. Nevertheless, in the smallest height and diameter classes, an increased abundance of other shade tolerant species (maple (Acer platanoides L.) and lime (Tilia cordata Mill.) was observed. Norway spruce (Picea abies Karst.) mainly formed a scattered second forest floor and, apparently, competed with hornbeam. Light parameters, particularly, the diffuse radiation, had a significant effect (p=0.05) on the distribution and abundance of hornbeam understory. The threshold values of irradiation parameters for hornbeam were notably higher compared to other species. The number and height of hornbeam saplings correlated tightly with the amount of available light. Nevertheless, under sufficient light conditions hornbeam showed good vitality, thus suggesting suitability of growing conditions.

In Latvia, two European ash (Fraxinus excelsior) genetic resource forests (GRF) have been designated in Skrīveri and Bērvircava. However, as the degree of damage of ash by the pathogenic fungus Hymenoscyphus fraxineus has increased, many stands have died and many do not comply anymore with minimum requirements for GRF. The aim of the present research was to evaluate and examine the quality of ash GRFs. In each forest unit, one 20×20 m plot was established, and the first (E3) and second (E2) layer projective cover of each species was determined in August 2014. All undergrowth and advance regeneration species were counted and the degree of ash damage by H. fraxineus was determined along a diagonal 25×1 m transect in each plot. In total, 101 plots were established. Quality evaluation was carried out according to the basic criteria for selection of GRF as well as based on criteria cited in other research. Their variation was established by using principal component analysis. Ash in layer E3 was better maintained in Skrīveri, but ash regeneration there was worse, as well as a higher degree of damage by H. fraxineus was observed. Ash regeneration density is significantly influenced by its cover on layers E3 and E2 as well as by tree species dominating the growth. The most valuable GRFs have been maintained in Skrīveri where 50% of units were rated of average quality and few of bad quality. In Bērvircava, 56% of forest units were of bad and very bad quality.

Wind is an important natural disturbance factor in a forest ecosystem. It creates gaps in a forest canopy, providing microenvironmental conditions, suitable for forest regeneration and affects the species composition of ground vegetation. Most of the studies analysing consequences of wind-storm have addressed short-term changes or influence the stand structure, but the aim of our study is to analyse ground-vegetation long time after windstorm in hemiboral forests. Data on ground vegetation cover have been collected in areas affected by the storm of 1967, where due to salvage-logging 200-400 m wide clearcuts were created. Sample plots (1×1 m) were placed in different distance from the edge of former clearcuts and projective cover of ground vegetation assessed using Braun-Blanquet method in Myrtillosa mel. forest type on 5 sites in north-western part of Latvia. Results reveal that in all sites species belonging to boreal, boreal-temperate and temperate biome were present, but their proportions varied between sites. In total 82 species of vascular plants were found, most frequent among them Maianthemum bifolium (L.) F.W.Schmidt (species characteristic to Norway spruce forests), Vaccinium myrtillus L. and Vaccinium vitis-idaea L. (associated with Scots pine forests) as well as Molinia caerulea (L.) Moench and Deschampsia caespitosa (L.) P.Beauv. (both characteristic to wet soils). Results suggest, that even 47 years after the storm microenvironmental conditions in the sites are not stable. Ellenberg’s indicator values reveal, that most of the sites are in semi-shade, cool and moist conditions, placed on acidic, nitrogen-poor (in few sites – also nitrogen rich) soils.