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Tomatoes (Solanum lycopersicum L.) are good source of several biologically active compounds and antioxidants, especially lycopene, phenolic compounds, and vitamins. Tomatoes are found all over the world and are cultivated in a wide variety of environmental conditions. Light-emitting diode (LED) lamps are increasingly being used in the cultivation of tomatoes due to their cost-effectiveness and wide range of possibilities to adapt the spectrum of light emitted to the needs of plants. The aim of this study is to evaluate the effect of different additional lighting used in the greenhouse on the accumulation of biologically active compounds in different varieties of tomato fruit. Chemical composition—content of organic acids, lycopene, total carotenoids, total phenolics and flavonoids as well as dry matter, soluble solids content, and taste index were determined in five tomato cultivars (“Bolzano F1,” “Chocomate F1,” “Diamont F1,” “Encore F1,” and “Strabena F1”), which were cultivated in greenhouse in an autumn-spring season by using additional lighting with 16 h photoperiod. Three different lighting sources were used: LED, induction (IND) lamp, and high-pressure sodium lamp (HPSL). Experiments were performed during 3 years. Results showed that tomato varieties react differently to the supplemental lighting used. Cultivars, such as “Encore” and “Strabena,” are the most unresponsive to supplemental light. Experiments have shown that HPSL stimulates the accumulation of primary metabolites in tomato fruit. In all the cases, soluble solids content was 4.7–18.2% higher as compared to other lighting sources. As LED and IND lamps emit about 20% blue-violet light, the results suggest that blue-violet light of the spectrum stimulates the accumulation of phenolic compounds in the fruit by 1.6–47.4% under IND and 10.2–15.6% under LED compared to HPSL. Red fruit varieties tend to synthesize more β-carotene under supplemental LED and IND light. An increase of blue promotes the synthesis of secondary metabolites.

Latvijas Universitātes Ķīmijas fakultātes studentu apmācību no 1920. līdz 1953. gadam vadīja Kārlis Štrenks (1886–1958). Viņš izcēlās ar savdabīgu, labi izstrādātu mācību metodiku un stingrām prasībām. Rakstā apkopots bagātais atmiņu materiāls par K. Štrenka pasniegšanas stilu, kā arī ziņas par viņa metodiskajiem līdzekļiem un zinātnisko darbu.

In this research, the aim was to determine teacher- and school-level factors that are associated with students’ civic knowledge, future engagement in society as a citizen, opinions about future global issues and sense of belonging to their country. For that purpose, the research took IEA International Civic and Citizenship Education Study (ICCS 2016) questionnaire data from Latvian and Finnish students (Latvia n = 3224, Finland n = 3173), teachers (Latvia n = 1933, Finland n = 2097) and schools (Latvia n = 137, Finland n = 174). The study used a subset of the teacher dataset that corresponds only to those teachers who teach civic and citizenship education lessons in school (Latvia n = 131, Finland n = 165). The research shows that there are some significant relationships with teacher- and school-level factors and four student factors: civic knowledge, future engagement, sense of belonging to their country and global problems (sustainability, violence and economy). The research supported by research application no. 1.1.1.2/VIAA/1/16/020.

A series of glassy 6-(tert-butyl)-4H-pyran-4-ylidene malononitrile (DCM) derivatives with covalently attached amorphous state promoting bulky 1,1,1-triphenylmethyl (trityl) moieties through several chemical design approaches have been synthesized and investigated for suitability in organic solid state laser applications. Results showed that the bonding type of such functional groups had a considerable influence on glass structure forming dye thermal properties and a slight influence on their optical properties. Thermal stability up to 346 °C was achieved with glass transitions in the range from 39 to 138 °C. Incorporation of bulky triphenyl substituents via ester groups showed remarkable amplified spontaneous emission (ASE) threshold energy value reduction by 1.7 times in comparison to other bonding approaches with excitation threshold energy density up to 91 µJ/cm2. Synthesized dyes show potential as the light-amplification medium component in organic solid state lasers.

This study explores the relationship between civic and citizenship factors and the middle proficiency level of students’ civic knowledge in the Baltic countries: Estonia, Latvia and Lithuania. The study uses large scale data from the IEA’s International Civic and Citizenship Education Study (ICCS) 2016. According to ICCS 2016, 39% of students from the three Baltic countries and only 26% of students from the Nordic countries had a middle proficiency level of civic knowledge. This middle proficiency level is the largest group in comparison to other levels. Therefore, the study aims to recognise the differences between the highest and lowest achievements in the middle proficiency level of civic knowledge and to examine the relationship between factors such as background, values, behaviour, citizenship activities and attitudes. Multivariable linear regression was used for the data analysis, creating several models. The results show that there are different factors associated with the highest and lowest achievements in the middle proficiency level. For example, the results indicate that students with a lower proficiency level participated in illegal protest activities more often and had lower critical thinking skills. Moreover, the research investigates differences inside the middle proficiency level of civic knowledge and between the lowest middle-level students and students from the lower level of civic knowledge.

ORM rīki ir populāra izvēle ASP.NET lietotnes loģiskā slāņa savienošanai ar datubāzi. Tomēr jauniem izstrādātājiem ne vienmēr var būt skaidrs un zināms, kādu ORM rīku izmantot lietotnes realizācijā. “Bakalaura” darba galvenais mērķis ir izpētīt ASP.NET ORM rīku piedāvājumu un veikt savstarpēju salīdzināšanu autora izvēlētā ORM rīku izlasē. Darbā tiek izprasts, kas ir objektorientēta kartēšana, kādus ORM rīkus piedāvā ASP.NET ietvars, un tiek veikts izvēlētu ORM rīku praktisks salīdzinājums. Lai veiktu praktisku salīdzinājumu, tika izveidota ASP.NET lietotne, datubāze un vaicājumi, kas katram ORM rīkam ir jāizpilda. Praktiskā pētījuma rezultātā ir formulēti secinājumi par katru ORM rīku, analizējot iegūtos datus., ORM tools are a popular choice for connecting the logical layer with the database in an ASP.NET application. But for new developers it may not always be clear, which ORM tool to use for developing an application. The main goal of this bachelor’s paper is to research the provided ORM tool selection by ASP.NET and to conduct a comparison of an ORM tool set chosen by the author. Within the paper answers are found to what is object relation mapping, what ORM tools the ASP.NET platform provides, and a practical comparison of chosen ORM tools is performed. To perform the practical comparison, the following were made: an ASP.NET application, a database and queries that the ORM tools have to implement. The results of practical research are analysed and conclusions are drawn about each ORM tool.

Ķīnas laikmetīgā māksla ir dzimusi zem vēsturiska sloga. Lai iepazītu sevi, ir jāpazīst savi priekšteči. Balstoties uz šādu sakāmvārdu, darbā tiek analizēti vēsturiski notikumi un personības. Darbā izcelto mākslinieku vēsturiskā pagātne, to bērnība un studiju gadi kas veidojušas viņu unikālo pieeju mākslai. Aizsākoties ĶTR un tās sociālistiskajai programmai, tās ietekmē tika likti pamati mākslas ievirzei vanguardismā, vēlāk sociālajā reālismā sekojot avangarda kustībai un transformējoties par Ķīnas laikmetīgo mākslu. Valsts sociālo un politisko pārmaiņu vidū, cenšoties izdzīvot un rast iespēju izpaust savas ieceres un uzskatus. Tajā pat laikā saglabājot sociālo atbildību pret valsti un vēlmi paust savu personīgo viedokli. Nespēja un nepakļaušanās šādiem uzstādījumiem ir novedusi pie daudzu nozīmīgu Ķīnas mākslinieku emigrācijas uz ārvalstīm. Kopš komunistiskās cenzūras, cīņas par demokrātiju un nesenajām valsts ekonomiski politiskajām reformām kas Ķīnu atvēra pasaulei un pasauli Ķīnai. Aktivizējās mākslas darbu tirgošana globālajā tirgū, to kolekcionāru skaita krasa palielināšanās, mākslas institūciju uzplaukums Ķīnā. Šo norišu rezultātā Ķīnas laikmetīgā māksla ieguva savu pašreizējo veidolu un atpazīstamību. Patreiz Ķīnas mākslas tirgus un tās dalībnieki ir vieni no visaktuālākajiem dalībniekiem globālajā mākslas scēnā. Mākslas darbu izsoļu rekordi, plašas retrospektīvas izstādes pasaules lielākajās mākslas institūcijās un sociāli-politiska mākslinieku iesaiste globālu jautājumu aktualizēšanā. Bakalaura darbs tika izstrādāts pamatā izmantojot gadījuma analīzi, kurā konkrētāk tiek pētītas sociālas grupas, notikumi, to lomas un attiecību analīze. Darba saturs tapis par humanitāro un mākslas zinātni, konkrētāk vizuālās mākslas apakš nozari. Darba garums ir 56.lpp., Chinese contemporary art was born under historical pressure. To fully understand yourself you need to understand your ancestors. Based on this saying, in this work I will analyze historical events and personalities. Highlighted artist historical background, their childhood and university years where the aspects that made their unique artistic approach. With the beginning of People’s Republic of China (PRC) and its socialist program, in its influence were made foundries of vanguardism, later social realism and avant-garde movements and transition to China contemporary art. In a middle of social and political turnovers, trying to survive and find an opportunity to express their intentions and views. At the same time maintaining social responsibility towards the state and the desire to express their personal views. Failure and disobedience to such settings has led to the emigration of many important Chinese artists abroad. Since communist censorship, the struggle for democracy and the recent economic and political reforms of the country that opened China to the world and the world to China. The sale of works of art in the global market, the sharp increase in the number of their collectors, the flourishing of art institutions in China took place. As a result of these developments, Chinese contemporary art gained its current form and recognition. Today, the Chinese art market and its players are among the most relevant players in the global art scene. Art auction records, extensive retrospective exhibitions in the world's largest art institutions and socio-political involvement of artists in actualizing global issues. The bachelor's thesis was developed mainly using a case study, in which social groups, events, their roles and relationship analysis are more specifically studied. The content of the work has become a humanities and arts science, more specifically a sub-branch of visual arts. Bachelor’s thesis consists of 56 pages.

Šajā darbā tiek aprakstīts laikrindu anomāliju noteikšanas modeļa izstrādes process un tā realizācija. Darbs tiek balstīts uz temperatūras mērījumu sensoru datiem. Anomāliju noteikšanas modeļa izstrādes ietvaros tiek apskatītas sekojošas tēmas - simulāciju veidošanda, laikrindu analīze, laikrindu priekšapstrāde, laikrindu klasterēšana, laikrindu prognozējošo modeļu izveide, anomāliju noteikšana un modeļu ansambļa izveide. Darba mērķis ir apskatīt dažāda tipa modeļus, metodes un to apvienojumus, lai izveidotu robustu anomāliju noteikšanas modeļu ansambli. Darba rezultātā tika izveidots laikrindu anomāliju noteikšanas modeļu ansamblis, kura pamatā ir četri modeļi - LightGBM, LSTM, Holt-Winters un laikrindu apakšperiodu klasterēšana. Modelēšana un analīze tika veikta programmēšanas valodā Python un darba pielikums satur JupyterLab darba grāmatas., This thesis describes time series anomaly detection process and servs as a guild for time series anomaly detection model creation. Analysis and models created in this thesis are created for temperature measurement time series data. In this thesis anomaly detection development process covers following topics - time series simulations, time series analysis, time series preprocessing, time series clustering, time series forecasting, anomaly detection and ensemble model creation. The main goal of this thesis was to reseach and compare different time series models, methods and different model and method combinations to create ensemble model for robust real-time anomaly detection. This thesis resulted in creation of anomaly detection ensemble model that contains following four models - LightGBM, LSTM, Holt-Wintersa and time series subperiod clustering. Modeling and analysis was done in Python programming language and all JupyterLab notebooks are available in attachment.

Virtualization has enabled the commoditization of cloud computing, as the hardware resources have become available to run different environments and share computing resources amongst different enterprises. Two technology types are commonly used in virtualization of hardware, namely, hypervisor and container. The present paper concerns only container technologies. A comprehensive overview of the container technologies for virtualization and the dynamics of their popularity have not been available yet. Without such an overview, the informed fast choice of technologies is hindered. To fill this knowledge gap, a systemic literature review was conducted to reveal the most popular container technologies and the trends in their research.

The paper focuses on the real-world usage of IEEE 802.11 wireless network encryption and Wi-Fi Protected Setup (WPS) function. A brief history on the development of encryption methods and WPS is given. Wireless scanning of 802.11 networks in a capital city has been performed, and the results of it have been analysed. To ascertain the knowledge about the security of wireless networks of the average user, an online survey has been conducted. To test the security of encryption methods and WPS function, practical attacks against private test wireless networks have been made. The authors conclude that the safest way to set up 802.11 network with a pre-shared key is to use Wi-Fi Protected Access 2 (WPA2) encryption without support for WPS function. Statistics in Riga shows that networks are often configured otherwise and thus vulnerable to attacks. Survey results prove that respondents are not well informed regarding the security of wireless networks.

Darbs ir veltīts Empīriskās ticamības (EL) metodei. Ir aplūkotas dažādas literatūrā atrodamās EL pieejas vāji atkarīgiem datiem vienas izlases gadījumā. Tā kā divu izlašu gadījums šajā kontekstā līdz šim nav pētīts, tiek formulēta divu izlašu blokveida empīriskās ticamības (BEL) metode, balstoties uz \textit{Kitamura} formulēto BEL metodi vienas izlases gadījumā. Tiek pierādīts klasiskais $\chi^2$ robežsadalījums un pētīts interesējošā parametra $\Delta$ asimptotiskais sadalījums. Tiek aplūkota gludinātā BEL metode divu izlašu kvantiļu starpībai, kas neiekļaujas vispārīgu novērtējošo vienādojumu formulējumā. Vēl tiek apskatīta Bārtleta korekciju iespējamība divām izlasēm vāji atkarīgiem datiem. Beigās tiek piedāvāti daži no iespējamiem šīs metodes lietojumiem., This work is devoted to empirical likelihood (EL) method. We look at some of the approaches that can be used to deal with weakly dependent data in one-sample case. Since two-sample problems in this context have not been considered before we introduce two-sample blockwise empirical likelihood (BEL) based on \textit{Kitamura} approach in the one-sample case. Classical $\chi^2$ limit distribution is proved and also asymptotic distribution of parameter $\Delta$ is considered. We look at the smoothed BEL method for difference of two-sample quantiles which does not fit in the classical BEL formulation. We also take a short look at Bartlett corrections for weakly dependent two-sample problems. At the end we propose some potential applications.

The most common method to determine the presence of clay in lakebed is coring method. This method requires survey of the whole lake area using stratified sampling method which is time and physical labour consuming process. To lessen the amount of coring samples and narrow the area of clay survey thus making the whole process faster and more effective, research was made to determine the possibility to indentify clay and its sediments using georadar survey or ground penetrating radar (GPR) method. GPR data analysis and coring studies in lake Zeiļu were used to evaluate GPR as potential method in lake clay sediment research. GPR method was tested in summer and winter during ice-covered period.