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Macro-crustacean fauna of the Vrana Lake Basin in Dalmatia (Croatia)
No full textThe shallow Vrana (Vransko) Lake in Dalmatia, Croatia, is a brackish water (oligohaline) lake that was artificially connected to the Adriatic Sea by the Prosika Canal, built in the 18th century. The aim of this study was to provide an updated overview of macro-crustacean diversity (class Malacostraca) in the Vrana Lake Basin. This synthesis includes all available records, combining the author's field observations with data from the scientific literature, and focuses on macro-crustacean taxa within the orders Amphipoda, Decapoda, Isopoda, and Mysida. Benthic macroinvertebrates were sampled using a hand net between 2011 and 2022, while baited crayfish traps were deployed during a one-night sampling effort in May/June 2024. Specimens of the invasive blue crab were collected manually in 2023 and 2024. In total, 32 sites were surveyed, 29 with a hand net and three exclusively with baited traps. A total of 21 macro-crustacean taxa were recorded in the Vrana Lake Basin between 2011 and 2024, comprising 16 species and five genera. The order Amphipoda was the most taxonomically diverse, with 11 taxa, followed by Isopoda (4), Decapoda (4), and Mysida (2). The highest species richness (16 taxa) was observed at the mouth of the Prosika Canal into the Adriatic Sea. The macro-crustacean fauna of the Vrana Lake Basin represents a unique assemblage of freshwater/oligohaline and brackish/marine species. The freshwater/oligohaline species, including the isopod Proasellus coxalis, amphipod Niphargus dalmatinus, and decapods Palaemon antennarius and Austropotamobius fulcisianus, were more abundant and widely distributed in the tributaries, with P. coxalis and P. antennarius also occurring in the lake. Most of the brackish/marine species were recorded only at the mouth of the Prosika Canal into the Adriatic Sea. Amphipods Gammarus aequicauda and Pectenogammarus stocki, and the isopod Lekanesphaera hookeri, were dominant in the lake and the Prosika Canal during, and immediately after periods of increased salinity. A recent addition to the brackish/marine group is the invasive blue crab (Callinectes sapidus), whose continued spread may pose a serious threat to biodiversity in the Vrana Lake Basin. The endangered white-clawed crayfish (A. fulcisianus) was recorded only in the freshwater Lateral Canal. Its continued monitoring is essential to assess the effectiveness of conservation measures, especially in light of planned sediment and vegetation removal to maintain flow in the canal. Salinization remains the primary threat to aquatic biodiversity in the basin. Urgent implementation of active management strategies, such as construction of a movable gate on the Prosika Canal, is necessary to mitigate this risk. The data presented in this study are critical for understanding and anticipating future changes in the macro-crustacean assemblages of this ecologically sensitive ecosystem
A new record of the critically endangered Smoothback angelshark Squatina oculata from Algerian waters (GFCM-GSA 04): biological data and implications for management
No full textThe Smoothback angelshark Squatina oculata is classified as Critically Endangered on the IUCN Red List of Threatened Species. It has been extirpated from much of its historical range, resulting in a significantly reduced and fragmented current distribution across the Mediterranean. New occurrence records, combined with biological data, are crucial to guide effective conservation measures in the basin. Here, we report the bycatch of a Smoothback angelshark off El Kala waters, at the extreme eastern boundary of Algeria (GFCM-GSA 4), in June 2025. The specimen was identified as a subadult female, measuring 857 mm in total length and weighing 5606.5 g. For the first time in this subarea, morphometric characteristics of an angel shark species were documented, complemented by the integration of Local Ecological Knowledge from fishermen. The possible establishment of a viable S. oculata population in the fishing grounds remains an optimistic hypothesis that cannot be excluded. This rare record from Algerian waters provides valuable insights to help fill knowledge gaps on the species in the southwestern Mediterranean and underscores the urgent need for targeted monitoring and conservation actions in the region
Study on a Constitutive Model for Predicting Hot Deformation Behavior of 34CrNi3MoA Steel for Reducer of Mining Equipment
No full textAs a high-strength medium-carbon quenched and tempered steel, 34CrNi3MoA is used in mining equipment reducer gears primarily due to its excellent mechanical properties, wear resistance, and impact resistance, meeting high-load demands under complex conditions. To develop an accurate constitutive model for predict-ing its high-temperature flow behavior, thermal compression tests were conducted on a Gleeble-3800 simulator at (1000–1200) °C and (0.01–10) s⁻¹ strain rates. A strain-compensated Arrhenius model was established using test data, with its predictability analyzed via correlation coefficient (R) and average absolute relative error (ARRE). Results show the model accurately predicts flow behavior under these conditions, with R = 0.9933 and ARRE = 5.244 %. These findings provide a reference for initial design and numerical prediction of 34CrNi3MoA’s high-temperature flow behavior, and are significant for numerical simulation and parameter optimization in its hot forming processes
Nutritive composition and labelling compliance of pre-packaged fresh eggs from Croatian producers
No full textThe nutrient composition makes the chicken egg a perfectly balanced food in the human diet, serving as a dietary source of protein, fat, and other nutrients. Easily accessible, eggs can be found in almost every household. Although manufacturers are not required to provide nutritional information on egg packaging, many have recognised the benefits of highlighting the nutritional declaration on their products. The aim of this study was to analyse the nutritional composition of different grades of eggs from different producers and farming systems, and to assess compliance with the nutritional tables declared on the products. The study covered a period of five years, from 2020 to 2024, during which 107 packs of fresh chicken eggs from five different Croatian producers were analysed, including barn and cage reared eggs, and different weight classes (M and L). The results showed that the eggs from Croatian producers have high nutritional value and nutrition tables listed on the packaging are accurate for each evaluated class of eggs, for all five producers. In addition, all product labels complied with the requirements for nutritional information in the form of nutritional tables set by the European Union regulations
An Algorithm for Microphone Array Sparse Arrangement and Acoustic Imaging
No full textAcoustic imaging is a technology for visualizing sound fields, which can be used in fault diagnosis of power equipment and gas leak detection. A spiral microphone array with a large number of microphones is generally used in ultrasonic acoustic imaging, but its application is limited due to the high cost. This paper addresses the issue of the high cost for acoustic imaging microphone arrays. On one hand, an adaptability function suitable for acoustic imaging applications is designed, and the genetic algorithm is used for sparse array arrangement to reduce the cost. On the other hand, the beam forming algorithm is also improved by using a time-varying smoothing coefficient to update the cross-power spectral matrix, further enhancing the performance. Experimental results show that by using the algorithms proposed in this paper, a sparse array can achieve acoustic imaging performance close to that of a large array, the cost of usage is significantly reduced
Enhancing Recommendation Accuracy of Item-Based Collaborative Filtering under Data Sparsity
No full textData sparsity remains a major challenge for collaborative filtering (CF) systems, where enhancing recommendation accuracy with limited data is crucial. Traditional CF methods depend on common ratings for similarity computation but often ignore users' bounded rationality in neighbor selection and rating behavior. To overcome these limitations, we propose an Expected Utility-based Collaborative Filtering (EUCF) method with three key contributions: (1) a positioning function computing item expected ratings to capture global patterns, (2) a dynamic similarity criterion incorporating item rating frequency and user rating saturation for adaptive neighbor selection (threshold ε), and (3) an average deviation correction model addressing imperfect ratings. Experiments on MovieLens-1M and Netflix show EUCF outperforms KNN-IBCF, improving MAE by 3.56% and 4.17%, and MSE by 6.02% and 6.45%, respectively. Moreover, EUCF boosts recommendation coverage by 9.96% and 11%, mitigating data sparsity and long-tail challenges. With reduced computational complexity, EUCF ensures better scalability for real-world deployment. The results demonstrate its effectiveness in balancing accuracy, efficiency, and robustness under sparse data conditions
Genetic variability of Linnaea borealis – remnant of Eastern-Southeastern Alpine populations indicates a strong bottleneck and in situ glacial survival
Get PDFIn a rapidly changing environment, habitat loss and fragmentation have primarily led to a decline in the numbers of numerous plant species. We compared the genetic variability of two small, isolated populations of Linnaea borealis L. with three populations from the core distribution area in the boreal region. The results show three main clusters, exemplars from the boreal distribution area being represented in all three clusters. The genetic variability within the two isolated Eastern-Southeastern Alpine populations was found to be very low, while genetic variability between them was very high. In addition, a low proportion of different genotypes was revealed in the Eastern-Southeastern Alpine populations as compared to the northern population. The high genetic variability between the two isolated Eastern-Southeastern Alpine populations indicates that most likely both are glacial relict populations, probably due to consecutive bottlenecks and long-term isolation under specific environmental conditions. Glacial relicts, which tend to be associated with endangered habitats, deserve urgent attention, especially when the recent anthropogenically-driven environmental crisis is considered
Assessing the pure technical efficiency of public primary schools in the City of Zagreb
No full textThis paper is the first to assess the pure technical efficiency (PTE) of 111 public primary schools in the City of Zagreb during the 2022/2023 school year, using an input-oriented Data Envelopment Analysis (DEA) – BCC model. PTE was measured using two input variables (expenditures and number of teachers) and three output variables (average grades, number of pupils who passed the class, and secondary school enrolment points). The analysis revealed substantial variation in efficiency scores, with 20% of schools identified as fully efficient. The average efficiency score was 0.90, suggesting that, on average, schools could reduce inputs by 10 while maintaining current output levels. A follow-up super-efficiency DEA model was applied to rank efficient schools and identify best-practice examples that could serve as models for others. Based on super-efficiency scores, schools were grouped into five performance categories – best practice, efficient, near-efficient, emerging, and low efficiency. Additional findings suggest that larger schools tend to be more efficient and that benchmarking within peer-size groups can help uncover high-performing schools that might otherwise remain under the radar. The results underscore the importance of context-sensitive efficiency evaluation in education and highlight the need for improved data on school characteristics to support more comprehensive, actionable assessments
First record of Lindernia dubia (Linderniaceae) in Georgia, and note on L. procumbens in the South Caucasus
Get PDFLindernia dubia (L.) Pennell, a species of American origin, is reported for the first time from the South Caucasus. In 2023, a relatively large population of L. dubia was found in the Chorokhi River floodplain in the Autonomous Republic of Adjara, Georgia, the South Caucasus. The species is considered to be intensively spreading around temperate and subtropical regions worldwide, commonly occupying disturbed wetland habitats. The new record further expands the introduced range of the species in the Caucasus, where it was first reported from rice-growing regions of the Krasnodar Territory in 2017
Optimization of Batch Processing Through Advanced Management in Public Institution X
No full textThe article discusses the optimization of batch processing in a public institution through the implementation of a proprietary centralized batch management system. The research is based on the analysis of processing log entries from 2018 to 2023 and the implementation of a proprietary information interface developed in C# and connected to an Oracle database. The study highlights the importance of operator roles, structured work orders, and socio-technical alignment between technology and organizational processes. The analysis confirms that advanced planning significantly reduces processing time, thereby improving operational efficiency. However, the impact on overall process success is limited, as reliability appears to depend on additional organizational and infrastructural factors