Potato sector is one of the competitive areas of the European Union (EU) agriculture. Although Eurostat declared that in 2015 Lithuanian share in the EU-28 harvested production was modest and composed only 0.7%, according to Food and Agriculture Organization of the United Nations (FAOSTAT), this crop remained on the list of top 10 commodities by net production value in Lithuanian agriculture. However, over the past decades the Lithuanian potato sector survived undesired transformations. The aim of this paper is to analyse the changes of the main indicators, related to the potato sector, and vertical price transmission among the chain of potatoes in Lithuania. The conducted research indicates the most important development trends of the potato sector and applies econometric techniques to investigate if there is any long-run relationship between the farm and retail prices of potatoes for the period of 2010 to 2016. Although the statistics show the shrinking production and domestic consumption of potatoes in Lithuania, the analysis of the vertical price transmission does not provide evidence of market inefficiencies. The Johansen cointegration test confirms the existence of a long-run relationship between the farm and retail prices, while the Granger causality test shows that there is a bidirectional causality between the examined series. The M-TAR model does not provide evidence of the farm and retail price asymmetry in the long run.

With the growing demand for e-learning, as well with the striving for excellence, everyone worldwide is encouraged to improve and ensure the quality of e-learning. Quality assurance requires a supportive environment. The purpose of this paper is to propose procedures for evaluating and controlling the quality of e-learning materials. The article reflects on the approach, which is often mentioned in the field of quality assurance, procedures that characterize the processes, helps to sort them, track their progress sequence and identify those responsible. Clearly, the quality of online learning has many dimensions, but this article deals only with the part that relates to the quality of e-learning materials. In January 2018, experts from European Distance Education Secondary School, Riga Distance Education Secondary School and Riga 1st Distance Education Secondary School were interviewed. The questionnaire included questions about the quality assessment of the study materials. Based on the findings of scientific research literature and taking into account the good practice, procedures for the quality control of electronic learning materials were created. The article offers four procedures that include the use of a web-based checklist developed by the author. Activities of procedures can be divided into areas of responsibility that deal with developers of the material, methodological commission, material evaluators and IT administrator. Distance learning program implementers can use the proposed procedures in the process of making and monitoring electronic learning materials. In addition, the checklist helps to identify important conditions and requirements that affect the quality of the study material.

In the research evaluation of the ecosystem services provided by riparian forests in Latvia has been studied. The aim of this research is to investigate the methods and indicators for assessing the value of ecosystem services of riparian forests and to establish the most appropriate methods of ecosystem service valuation in the case of Latvia. The study is based on analysis of scientific publications, special literature and reports of international organizations, studying results of previously performed qualitative and quantitative research methods in the field of ecosystem service evaluation. The results of this study revealed several methods that could be applied for evaluation of ecosystem services provided by riparian forests, taking into account that the set of available data may be limited and considering the costs and span of time that may be necessary to collect the missing data. The results also show that the majority of ecosystem service evaluation indicators can be applied if appropriate earlier studies have been performed and feasible data for similar territories or conditions are available. The knowledge of the methods and indicators for evaluation of ecosystem services is a crucial factor in the decision making process, when decisions on economic development or sustainable management of ecosystem services are made.