خيارات البحث
النتائج 861 - 870 من 2,098
Factors affecting smoked fish quality: a review
2020
Puke, S., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Galoburda, R,, Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
Smoked sprats (Sprattus sprattus balticus) from the Baltic Sea are one of the most popular processed fish products in Latvia. The amount of catching and demand is annually increasing. For producers, it is important to provide stable quality throughout the year, which sometimes is challenging due to many factors. Smoked fish quality depends not only on the seasonality, but also on the applied technologies. The aim of the current study was to review research findings about factors affecting the smoked fish quality. The databases of Science Direct, Web of Science, Wiley Online Journals and Google Scholar were searched. The first parameter that affects quality of fish till processing is raw material, its catching place and season, as well as whether it is fresh or frozen fish, that includes not only microbiological parameters, but also physical and chemical changes in fish depending on the storage conditions. The second parameter is the applied pre-treatment methods (using salt, acids) before processing, which can improve fish texture and make better result for smoked fish. The third parameter is the used technology for the fish processing, heat treatment methods use of wood chips or liquid smoke, or adjustment of smoking conditions. These all together make a lot of sensorial and textural changes in the final product. If any of these parameters is changed during processing, they can affect the smoked fish quality. Therefore, to ensure constant quality of smoked fish, in-depth knowledge of parameters is extremely important.
اظهر المزيد [+] اقل [-]Cattle (Bos taurus) endometrium morphology on the seventh day of the estrous cycle
2020
Ponomarjova, O., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Sematovica, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Piginka-Vjaceslavova, I., Institute of Food Safety, Animal Health and Environment “BIORˮ, Riga (Latvia) | Vanaga, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
The aim of our study was to describe the histopathological and cytological characteristic of the cow endometrium on the seventh day of the oestrous cycle. In this study, 11 different breeds’ dairy cows (78.18 ± 37.46 months old, in 3.6 ± 2.17 lactation, the mean body condition score 3.4 ± 0.72 (5 points scale)) from Research and Study farm ‘Vecauce’ were selected. All cows were more than 210 days postpartum. Overall health and reproductive tract examination was performed, progesterone (P4) and estradiol (E2) concentration in blood serum were established and the biopsy and cytology samples of endometrium were taken. Mean E2 concentration was 14.92 ± 7.92 pg mLE−1, mean P4 concentration was 13.64 ± 9.44 nmol LE−1. The mean percentage in the cytology slides was established: epithelial cells 89 ± 9%, polimorphonuclear leukocytes (PMN) 6 ± 5%. Cytological subclinical endometritis (SE) was confirmed in 5 cows. Histopathological findings (out of 22 samples): endometrium stromal edema in 14, hemosiderin and hemosiderophages in 8, supranuclear vacuolization in 12, pseudodecidual reaction in 12 samples. No subnuclear vacuolization and mitosis in the glandular epithelium were detected. Histopathological examination did not reveal SE. Morphology between the uterine horns with and without corpus luteum (CL) and between cows with serum P4 level higher than 15 nmol LE−1 and lower than 15 nmol LE−1 were not statistically different (p is greater than 0.05). In conclusion, histopatological examination is more reliable diagnostic method for SE. Future investigation should be performed to establish cut-off values for the diagnosis of SE in cows more than 210 days postpartum.
اظهر المزيد [+] اقل [-]Legal and managerial solutions of public sector authorities for preserving ecosystem services of the lakes
2020
Marcinkeviciute, L., Vytautas Magnus Univ., Kaunas (Lithuania) | Vilkeviciute, J., Vytautas Magnus Univ., Kaunas (Lithuania) | Zukovskis, J., Vytautas Magnus Univ., Kaunas (Lithuania)
Although the problem of ecosystem diversity loss is of a global nature, the measures to solve it must be implemented at the national level. As a member of the European Union, Lithuania needs to have a clear position regarding the application of proposed socio-economic measures. The problems of lake ecosystem utilisation analysed in the article are based on the scientific knowledge which complies with the specifics of regional natural environment. The aim of the article is to systematize scientific knowledge about modern lake ecosystem services by explaining the fundamental adaptation patterns of ecosystems and their components. The article provides a complex assessment of the services provided by lake ecosystems, reveals management problems related to optimization of the use of lake ecosystems, presents recommendations on the improvement of legislation related to lake ecosystem services, regulations for protected areas, management plans, etc.
اظهر المزيد [+] اقل [-]Testing an operation of prototype for automated assessment: case of visitor profile of Gauja National Park
2020
Berzina, I., Vidzeme Univ. of Applied Sciences, Valmiera (Latvia) | Balodis, E., Vidzeme Univ. of Applied Sciences, Valmiera (Latvia)
This study is based on the authors’ research started in 2017 that resulted in the development of theoretical strategic and tactical models for the construction of a prototype for automated assessment of tourism economic impact in specific regions, including regions of national parks (NP), as well as for other studies. The aim of the research was testing the performance of the prototype in a research e-environment using the travellers’ survey data obtained in a study in 2019 on the national parks’ target groups (visitor behaviour) during the Gauja National Park (GNP) Travellers’ Days. The prototype was based on the open-source platform Drupal, MySQL used as a database management system (DMS). Drupal united with the Jupyter Notebook platform. The methodological substantiation of the test study is based on aspects of consumer behaviour. A quantitative study with details of qualitative research has been performed. Simple data sampling was used in the data acquisition, but in the analysis – induction, deduction approach, synthesis, data sorting and segmentation, determination of mean values and their expression in proportion; a comparative analysis was performed and conclusions characterizing the sample were made. After completing the prototype performance testing, the authors’ main findings indicate that the prototype’s performance efficiency in terms of time consumption is 23.3 times higher than equivalent work in MS Excel. The prototype has yielded quantitative results from the calculations, and that allows the formulation of the GNP’s Travellers’ Days visitor profile, which is characterized by a sample of the surveys.
اظهر المزيد [+] اقل [-]The change of natural landscape in Lithuania
2020
Ivaviciute, G., Vytautas Magnus Univ., Kaunas (Lithuania);Kaunas Forestry and Environmental Engineering Univ. of Applied Sciences (Lithuania);Klaipeda State Univ. of Applied Sciences (Lithuania)
The purpose of this article is to carry out an analysis of the natural landscape of the Republic of Lithuania in 2004–2019. During the preparation of the article, the following scientific methods were used: literature analysis, determination and evaluation of the current situation, grouping method, comparison method, graphical method, analytical and statistical analysis methods, logical analysis. The article analyses the change of the area of natural (natural, subnatural) landscape components (natural forests, wetlands, water bodies) during the period between the years 2004 and 2019. The analysis showed that the two components of the natural landscape of the Republic of Lithuania during 2004–2019 increased: the forest area (132,849.03 ha or 6.15%) and water bodies (3,668.49 ha or 1.38%). Unfortunately, the area of wetlands has decreased by 50,990.20 ha (35.05%). During the analysed period, the natural landscape of Lithuania increased by 85527.97 ha or 3.39%. At present, it is particularly important to care for and restore valuable landscape complexes to fulfil their ecosystem functions. One of the most important challenges is to reconcile urbanization and nature conservation so as not to reduce significant areas of the country’s natural landscape.
اظهر المزيد [+] اقل [-]Impact of the use of existing ditch vector data on soil moisture predictions
2020
Ivanovs, J., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Stals, T., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Kaleja, S., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Wet soils play an important role in hydrological, biological and chemical processes, and knowledge on their spatial distribution is essential in forestry, agriculture and similar fields. Digital elevation models (DEM) and various hydrological indexes are used to perform water runoff and accumulation processes. The prerequisite for the calculation of the hydrological indexes is the most accurate representation of the Earth’s surface in the DEM, which must be corrected as necessary to remove surface artefacts that create a dam effect. In addition, different resolutions for DEM give different results, so it is necessary to evaluate what resolution data is needed for a particular study. The aim of this study is to evaluate the feasibility of using existing ditch vector data for DEM correction and the resulting implications for soil moisture prediction. Applied methodology uses a network of available ditch vectors and creates gaps in the overlapping parts of the DEM. The data were processed using open source GIS software QGIS, GRASS GIS and Whitebox GAT. Ditch vector data were obtained from JSC Latvian State Forests and the Latvian Geospatial Information Agency. The results show that by applying the bottomless ditch approach in forest lands on moraine deposits, depending on the accuracy of the ditch vector data, the values of the prediction of the soil wetness both increase and decrease. On the other hand, in forest lands on graciolimnic sediments it is visible that predicted soil wetness values increase in the close proximity of ditches. For forest lands on glaciofluvial and eolitic sediments there were no visible changes because of lack of ditches.
اظهر المزيد [+] اقل [-]Financial sector evolution and competencies development in the context of information and communication technologies
2020
Arefjevs, I., BA School of Business and Finance, Riga (Latvia) | Spilbergs, A., BA School of Business and Finance, Riga (Latvia | Natrins, A., BA School of Business and Finance, Riga (Latvia | Verdenhofs, A., Riga Technical Univ. (Latvia) | Mavlutova, I., BA School of Business and Finance, Riga (Latvia | Volkova, T., BA School of Business and Finance, Riga (Latvia
The development of information and communication technologies (ICT) has a significant impact on the business model of companies operating in the financial sector. Digital transformation leads to changing existing business model rapidly, as well as necessity of developing new processes specifically related to the use of ICT in business processes, development of new products and updating existing ones. At present, changes in the demand for ICT related processes in financial sector are observed both through the development of different technologies and their applications core or ancillary processes (e.g. innovations in payment systems including crypto currencies, blockchain-assisted smart contract, credit markets and insurance including peer-to-peer lending). Based on the opportunities offered by ICT, new business models need to be developed in the financial sector to transform these capabilities into new products and services that respond to changing customer demand. The aim of research to investigate the changes taking place in financial sector in the light of developments in ICT for acquisition of necessary competencies. Research methodology includes systematic review of scientific literature, analysis of selected financial sector statistics, semi-structured industry expert interviews and statistics analysis. The empirical study is limited to the financial sector of Latvia. Although due to the global nature of the financial sector the research findings could be applied internationally.
اظهر المزيد [+] اقل [-]Deep learning solution for children long-term identification
2020
Bumanis, N., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Vitols, G., WeAreDots Ltd., Riga (Latvia) | Arhipova, I., WeAreDots Ltd., Riga (Latvia) | Meirane, I., WeAreDots Ltd., Riga (Latvia)
Deep learning algorithms are becoming default solution for application in business processes where recognition, identification and automated learning are involved. For human identification, analysis of various features can be applied. Face feature analysis is most popular method for identification of person in various stages of life, including children and infants. The aim of this research was to propose deep learning solution for long-term identification of children in educational institutions. Previously proposed conceptual model for long-term re-identification was enhanced. The enhancements include processing of unexpected persons’ scenarios, knowledge base improvements based on results of supervised and unsupervised learning, implementation of video surveillance zones within educational institutions and object tracking results’ data chaining between multiple logical processes. Object tracking results are the solution we found for long-term identification realization.
اظهر المزيد [+] اقل [-]Changes in the engineering students’ procrastination self-evaluation within the experimental approbation of career education program
2020
Jerkunkova, A., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Katane, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Baltusite, R., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia)
One of the modern education problems being investigated is a phenomenon of student procrastination and minimisation of its influence on achievement of career goals. A transformative pedagogical experiment was carried out involving 1st year engineering students of Latvia University of Life Sciences and Technologies during the 2018/2019 academic year. The aim of the transformative pedagogical experiment was to promote the reduction of student procrastination levels and achievement of their goals by practical experimental approbation of a career education program. During the experiment, self-evaluation of student procrastination was performed before and after the implementation of the career education program. The methodology included 20 indicators of procrastination self-evaluation. The program included three topic-based parts: 1) understanding and setting student career goals; 2) defining procrastination levels and factors; 3) the influence of procrastination minimisation on career goals’ achievement. The study results allowed to conclude that due to the career education program elaborated and implemented in practice, substantial changes in student procrastination self-evaluation took place during the transformative pedagogical experiment. There was a significant difference in student procrastination levels before and after the transformative pedagogical experiment. The study results demonstrated that the elaborated and experimentally implemented career education program is valid and can be further used for minimisation of student procrastination, it can contribute to career goals’ achievement and for the reduction of early discontinuation of studies and dropping out of university as there is a correlation between procrastination and dropout phenomena.
اظهر المزيد [+] اقل [-]Structural diversity of dead wood in small-scaled protected forest parcels in Latvia
2019
Liepa, L., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Straupe, I., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Miezite, O., Latvia Univ. of Life Sciences and Technologies, Jelgava (Latvia) | Jansons, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Dead wood is a significant component in forested ecosystems. In Fennoscandia and Baltic countries, set-aside forest areas, also called woodland key habitats (WKHs), have been created for nature conservation purposes in the production forest landscape. We performed a comparative study on dead wood substrate availability in different WKH types in Latvia. We measured standing trunks and downed logs to estimate biological quantities and qualities for coarse woody debris substrate. In this study, we found out that dead wood availability ranges, on average, from 38.2 to 149.5 m**3 haE−1. This study showed that moderate quantity and quality of dead wood has been found in different types, but the fine quality coarse woody debris was scarcely presented. In general, WKHs provide moderate and high level of qualities and quantities of structural features in the production forest landscape.
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