Jukuri

Tervetuloa käyttämään Jukuria, Luonnonvarakeskuksen (Luke) avointa julkaisuarkistoa. Jukurissa on tiedot Luken julkaisutuotannosta. Osa julkaisuista on vapaasti ladattavissa. Luken muodostaneiden tutkimuslaitosten aikaisemmasta julkaisutuotannosta osan tiedot ovat järjestelmässä jo nyt ja kattavuus paranee jatkuvasti.

Kokoelmat

Näytetään 1 - 2 / 2

Viimeksi tallennetut

Effects of alkalinity-controlling chemicals on biofilter performance and sludge properties in freshwater recirculating aquaculture systems
Qi, Wanhe; Vielma, Jouni
Aquacultural engineering (Elsevier, 2026)
This study aims to enrich potassium (K) content in sludge from recirculating aquaculture systems (RAS) by replacing sodium (Na)-based alkalinity-controlling chemicals with K-based derivates. Nine identical pilot-scale RAS rearing rainbow trout (Oncorhynchus mykiss) were operated for 10 weeks in triplicate treatments with K2CO3, NaHCO3, and NaOH as alkalinity-controlling chemicals. Water and sludge samples were collected weekly from the RAS for water quality and sludge property measurements. Results showed that K2CO3 significantly increased K concentrations, reaching average values of 190 mg/L in water samples and 180 mg/kg in sludge samples. These levels were 17–20 times and 14 times higher than those observed in NaHCO3 and NaOH treatments, respectively. All treatments achieved satisfactory biofilter performance (TAN < 1 mg/L and NO2--N < 0.2 mg/L), and good fish production performance (FCR=0.96–1.17, survival > 95%). Significant accumulation of Na in rearing water from NaHCO3 and NaOH treatments was observed with 133 ± 7 mg/L and 136 ± 2 mg/L at the end of experiment, respectively, which are far above phytotoxic Na threshold of 50 mg/L. In contrast, K2CO3 treatment maintained low and stable Na levels over sampling period, ranging from 4.0 ± 1.3 mg/L to 6.3 ± 0.6 mg/L. No difference observed among treatments on other sludge (TN, TP, DM, TSS and SVI30) and water (TN, TP, Ca, Mg, S, and Si) parameters. This study confirms that K2CO3 as an alkalinity-controlling chemical in RAS is a feasible and synergistic solution in unifying alkalinity adjustment and producing a K-rich fertilizer from RAS sludge, which enhances the sustainability and circularity of aquaculture production.
Detection of jeilongvirus circulation in Finnish urban rat populations by a novel pan-jeilong-RT-qPCR
Pulkkinen, Emilia; Sippola, Ella; Sgarabotto, Elena; Suomalainen, Nina; Lilley, Thomas; Meierhofer, Melissa B.; Aivelo, Tuomas; Zöldi, Viktor; Sallinen, Suvi; Smura, Teemu; Henttonen, Heikki; Huitu, Otso; Kinnunen, Tuure; Jääskeläinen, Anne J.; Sironen, Tarja
Journal of virological methods (Elsevier, 2026)
Paramyxoviruses can infect a variety of host species and cause infections among wildlife and humans. Some of these viruses can also cause severe zoonotic infections. Although new paramyxoviruses, such as jeilongviruses, are being recognized, little is known about their host species variation and pathogenesis. The current screening methods to detect paramyxoviruses are either laborious conventional PCR methods or costly next-generation sequencing methods. Therefore, we designed a new pan-jeilong-RT-qPCR assay to detect jeilong- and parajeilongviruses from wildlife samples and screened rat, shrew, and bat samples from Finland and Latvia. With this new real-time PCR assay, we detected jeilongviruses in Finnish urban rat populations during 2020–2023 with a 13% positivity rate, including beilong virus (Jeilongvirus beilongi). This finding highlights the abundance of jeilongvirus in rats and the need for continued surveillance and more detailed characterization of these novel pathogens to evaluate the zoonotic potential of these viruses in rat and other rodent populations.
Modelling of mechanized logging in uneven‑ and even‑aged forest structures subject to continuous cover forestry
Palander, Teijo; Lamminsalo, Juha; Väätäinen, Kari; Muhonen, Timo; Nuutinen, Yrjö
Journal of forestry research (Springer Nature, 2026)
The effect of forest structure affected productivity of harvester operator work in a continuous cover forest. In particular, the effects of the forests consisting of even- and uneven-age trees were compared. In addition to tree variables describing the structure of the forest, variables describing the time taken in each of the work phases were needed to accurately model the logging motions. Modelling also required single tree data from the harvester. The model precisely predicted the relationship between the variables and productivity in both the uneven-aged forest (R2 = 0.96) and the even-aged forest (R2 = 0.92). Both explanatory powers of models were statistically significant. Productivity was explained by the “volume of trunk”, the “length of the operating part of trunk”, the “moving time of the logging device to trunk”, the “felling time of tree” and the “processing time of trunk”. In the uneven-aged forest, the effective-hour productivity was 37.7 m3 E0h−1 and in the even-aged forest 43.5 m3 E0h−1. The work phases “moving the logging device to trunk” and “felling of tree” consumed more time in the uneven-aged forest. The results of the time and motion analysis justify the promotion of training both work phases to increase productivity of harvester operator work. This modelling approach can be recommended for studies on the development of selective logging method for continuous cover forestry.
Effect of Torulaspora delbrueckii and Saccharomyces cerevisiae fermentation on chemical composition of ciders made from traditional Finnish apple cultivars
Wang, Qizai; Laaksonen, Oskar; Jafari, Mahsa Sadat; Okwum, Ada Obianuju; Damerau, Annelie; Heinonen, Maarit; He, Wenjia; Yang, Baoru; Kelanne, Niina
Food bioscience (Elsevier, 2026)
This study investigated the impact of two yeast strains, Saccharomyces cerevisiae (SC) and Torulaspora delbrueckii (TD), on the chemical composition of ciders prepared from the juices of six traditional apple cultivars grown in Finland, aiming to evaluate the potential of these underutilized local cultivars for cider production. Sugars, organic acids and ethanol contents were analyzed using gas chromatography coupled with a flame ionization detector (GC–FID), while volatile compounds were identified and semi-quantified using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS–SPME–CG–MS). Apple cultivar selection had a stronger impact than yeast strain on the sugars and organic acids in ciders, whereas both factors shaped the volatile compound profiles. Among the cultivars, ‘Rambo’ demonstrated the greatest potential for cider aroma development. Specifically, fermentation of ‘Rambo’ juice with TD yielded the highest ester production among all TD-fermented ciders. Volatile profiling further revealed that TD favored the formation of fruity esters while reducing higher alcohol and acetic acid levels, resulting in potentially more complex and fruity aroma, compared to SC. Other cultivar–yeast combinations, such as ‘Aleksanteri’, ‘Antonovka’, or ‘Mustialan Iso Venäläinen’ with SC, could also enhance cider aroma complexity. These findings highlight the potential of underutilized apple cultivars, when combined with tailored yeast selection, to diversify cider profiles and to enhance sensory quality.
Advancement in Seed Collection Timing for Three European Tree Species: Abies alba, Larix decidua and Tilia cordata
Garbacea, Paula; Stoica, Emanuel; Alexandru, Alin-Madalin; Mihai, Georgeta; Himanen, Katri; Konrad, Heino
Seeds : 2 (MDPI AG, 2026)
The collection of high-quality seeds to produce forest seedlings is closely linked with the time of harvesting. Climate warming is already having visible effects in all life stages of forest tree species, including the timing of seed maturation. The purpose of this study was to update the knowledge on seed collection timing and to identify the indicators of physiological maturity for three key Eastern European tree species—silver fir (Abies alba), European larch (Larix decidua), and small-leaved lime (Tilia cordata). Seeds and cones were collected from Romanian clonal seed orchards and evaluated at several stages of seed maturation using germination tests for European larch and tetrazolium viability tests for silver fir and small-leaved lime. The results revealed species-specific differences in seed maturation timing: in silver fir seed viability increased slightly from late August to early September, in European larch germination remained low (≈20%) regardless of harvest time, while small-leaved lime viability declined significantly after late August. These findings suggest that the harvest period observed during the study years occurred earlier than the traditionally recommended intervals and could be linked to recent warming trends. This study highlights the relevance of re-evaluating seed collection schedules under changing climatic conditions, while further multi-year studies are required to confirm these patterns and refine practical recommendations.