This study examines the sustainability and economic viability of intensive common carp (Cyprinus carpio) production in recirculating aquaculture systems (RASs) in Hungary. Using a deterministic model, the research identifies production costs, profitability, and the critical factors influencing economic efficiency. It also evaluates the impact of key variables, such as the feed purchase price, the market-sized common carp sales price, the specific gross yield, the electricity price, and electricity consumption, on economic performance by using a sensitivity analysis. Primary data were collected from an experimental trial conducted under controlled conditions in Hungary, dividing the production process into three phases: pre-rearing, post-rearing, and market-sized fish production. The unit production cost of market-sized common carp in 2024 was 5.47 EUR/kg, with energy (47.01%) and feed (24.18%) as the main cost drivers. While the sales price covered variable costs, it failed to offset fixed costs, resulting in a loss of 0.41 EUR/kg. The results reveal that while RAS technology offers high productivity and efficient resource utilization, its economic viability is challenged by high initial investment and operational costs. Nevertheless, the study identifies optimization opportunities in feed management, water usage, and electricity efficiency to enhance sustainability and profitability. These findings emphasize the importance of integrating economic, environmental, and technological considerations to advance intensive aquaculture practices.

Within global meat production, the position of fish and fishery products are becoming more and more important because quarter of world's animal origin protein supply is produced by fisheries and aquaculture. Therefore the importance of freshwater fish production is also growing at both European and domestic levels. Most determinative quantities of EU-28 production at intensive technological levels are salmon (21.3%), trout (14.0%) and seabass (13.5%), in the aspect of the value of production trout is almost 15.1%.The goal of this study is to present the status of the trout production at international and EU, paying special attention to the main exporting and importing countries. During the research secondary data collection was carried out, which was based on international and national literatures and statistical databases. Following the evaluation of the sectoral production trends over and above the trade data of the sector, advantages/disadvantages of the trout trade was compared based on the comparative advantages (RCA) method. To calculate the RCA index for the different processed products data was provided by COMTRADE and EUROSTAT International Foreign Trade Databases over the 2012-2015 period. The study examines the production trends and the causative relationships behind the RCA index results in detail.

Energy poverty is a multidimensional phenomenon that impairs access to basic energy services and threatens social well-being, particularly in disadvantaged rural communities. This study investigates the extent and drivers of household energy poverty in a Hungarian village through a survey-based analysis (N = 257) conducted in early 2025. The sample is not nationally representative, however, it reflects approximately 20% of the total village population (1331 inhabitants). This study aims to identify vulnerable household profiles, explore correlations between socio-economic and housing factors and perceived thermal comfort, and compare the effectiveness of multiple measurement indicators the 10% rule, low income high cost, 2M, and M/2. We employ descriptive statistics, Pearson correlation, Fuzzy C-Means clustering, and linear regression, revealing that over half of the sample is energy poor according to the 10% rule, while the LIHC method identifies 29%. Our regression results confirm that cluster membership significantly influences perceived comfort levels (R² = 0.063, p = 0.002). We conclude that single-indicator approaches are insufficient to capture the nuanced realities of rural energy poverty, therefore, we recommend the development of a rural energy poverty index. Such a tool could help identify affected households and support the formulation of context-sensitive, evidence-based energy and social policy interventions.

Food insecurity persists even in high-income regions such as the European Union (EU), where more than 88 million tons of edible food are wasted annually. This study explores the relationship between food waste reduction and food security within the EU’s sustainability agenda, particularly the European Green Deal. Using a qualitative methodology, including a literature review and secondary data analysis from sources such as Eurostat, the Food and Agriculture Organization of the United Nations, and Our World in Data, we identify critical drivers of food waste—chiefly at the consumer level—and assess the environmental, economic, and social implications. Our findings indicate that reducing food waste can significantly enhance food availability, reduce greenhouse gas emissions, and preserve water and land resources. Interventions such as food banks, cold chain technologies, regulatory reforms, and support for local food systems are effective solutions. The study underscores the need for integrated policy frameworks that align technological innovation, consumer education, and circular economy principles. The study concludes that reducing food waste is not only an environmental priority but also a socioeconomic necessity for ensuring long-term food security, especially despite climate change and supply chain vulnerabilities.

Broiler transport density plays a crucial role in animal welfare, meat quality, and economic efficiency. The European Food Safety Authority (EFSA) has recently recommended increased space allowances for broilers during transport to improve welfare. This study statistically evaluated the effects of reduced stocking density under commercial Hungarian conditions. A total of 176,198 Ross 308 heavyweight broilers were transported over a 19 km distance at moderate springtime temperature (7–13 °C) using 33 trucks, of which 14 (7 control and 7 test) were included in the comparison. Control trucks followed the EU-regulated density (160 cm²/kg; 5610 birds/truck), while test trucks applied the lower EFSA-recommended density (200–210 cm²/kg; 4334 birds/truck). Dead-on-arrival (DOA) birds and carcass condemnations were evaluated for all transported birds, while injuries and bruising were assessed by sampling 277 carcasses per truck, consistent with industrial auditing practice. Significant differences were observed between the two treatment groups. The reduced-density group showed higher rates of DOA birds (0.61% vs. 0.36% in the control, a 69% relative increase), more wing injuries (6.91% vs. 4.28%, +61%), more bruising (6.76% vs. 3.40%, +98%), and a higher rate of carcass condemnations (0.78% vs. 0.57%, +38%). These findings indicate that increasing space allowance during transport may not improve welfare under moderate continental conditions and may even increase injury risk, with potential economic and environmental consequences for stakeholders. The results highlight the need for further research covering longer journey durations, wider temperature ranges, and alternative crate designs before the broad implementation of the EFSA-recommended transport densities.

Doctoral schools play a key role in training the next generation of researchers and renewing higher education. This study presents the operation, development directions, and international embeddedness of the Doctoral School of Business and Management Sciences at the University of Debrecen. It provides an overview of trends in student enrollment and degree completion, as well as the multidisciplinary and international character of the doctoral program. Special attention is given to the 2025 International Scientific Days conference, where 118 scientific presentations were delivered on topics such as digitalization, sustainability, and artificial intelligence. The study also highlights the significant growth in the doctoral school's publication performance, particularly in terms of internationally indexed, high-ranking academic journal articles. JEL code: A23; I23; O30