1221. Small but voracious : invasive generalist consumes more zooplankton in winter than native planktivoreŽiga Ogorelec, Alexander Brinker, Dietmar Straile, 2022, original scientific article Abstract: In recent years, Lake Constance has experienced an invasion and domination of three-spined stickleback (Gasterosteus aculeatus) in the pelagic zone, which has coincided with a decline in the native whitefish (Coregonus wartmanni) population. Similar massive invasions of sticklebacks into pelagic zones have been recognized also in marine areas or small lakes worldwide. However, their diet overlaps with native species is rarely evaluated, especially in the winter season, which often presents a bottleneck for fish survival. In this study, we compared the diet of pelagic sticklebacks with the diet of the substantially larger native whitefish in different seasons, to evaluate the threat of the recent stickleback invasion on whitefish populations. By monthly sampling of zooplankton and both fish species diets, we could demonstrate that sticklebacks select similar prey throughout most of the year and consume more prey than whitefish during the winter. With relations between prey availability and prey selection, interspecific and intraspecific seasonal diet variability and indices like a prey-specific index of relative importance, we discuss the importance of zooplankton species traits and abundance for whitefish and stickleback predation. This study shows that sticklebacks, despite their small size, represent a serious potential diet competitor to native planktivorous fish. Sticklebacks quickly adapt to new environments, and thus we advocate precautions regarding their introduction into similar lakes as Lake Constance, as this could cause irreversible ecological changes.
Keywords: Bythotrephes longimanus, Lake Constance, overwintering strategy, pelagic whitefish diet, planktivory, predator size, seasonal prey selection, stickleback invasion
Published in DiRROS: 18.07.2024; Views: 336; Downloads: 213
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1222. The freshwater balance of the Adriatic Seastudy : a sensitivity studyMartin Vodopivec, Klodian Zaimi, Álvaro Judice Peliz, 2022, original scientific article Abstract: The Adriatic Sea is a narrow semi-enclosed basin with considerable freshwater inflow, connected to the saltier Mediterranean Sea through a narrow strait. The northern and central parts of the basin are characterized by a shallow shelf, while the southern part features a pit exceeding 1,200 m in depth. We conducted a series of modeling experiments over a 16-year period (2000–2015) using different runoff configurations and different sources of atmospheric forcing to investigate the sensitivity of the Adriatic Sea circulation and hydrology to freshwater balance and heat loss. Our results show that the shelf salinity and the salinity of the surface layers in the southern Adriatic are part of a self-amplifying loop involving dense water formation, water exchange with the Mediterranean Sea, and salty water intrusions to the shelf. Therefore, the characteristics of the basin and the water circulation are highly sensitive to the freshwater budget and heat losses. River discharge is subject to large interannual variations and is poorly known for many of the Adriatic freshwater sources. To improve the accuracy of the freshwater budget, we created a new climatology for three Albanian rivers and modulated the monthly climatological discharge in accordance with the rivers Po and Isonzo (Soča). Evaporation, precipitation, and heat losses vary strongly among the available atmospheric reanalyses and we show that the choice of atmospheric forcing has a substantial impact on the hydrology and circulation of the Adriatic Sea.
Published in DiRROS: 18.07.2024; Views: 262; Downloads: 230
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1223. The cytotoxic effects of cannabidiol and cannabigerol on glioblastoma stem cells may mostly involve GPR55 and TRPV1 signallingTamara Lah Turnšek, Bernarda Majc, Metka Novak, Ajda Sušnik, Barbara Breznik, Andrej Porčnik, Roman Bošnjak, Aleksander Sadikov, Marta Malavolta, Selma Halilčević, Jernej Mlakar, Roby Zomer, 2022, original scientific article Abstract: Glioblastoma (GBM) is one of the most aggressive cancers, comprising 60–70% of all gliomas. The large G-protein-coupled receptor family includes cannabinoid receptors CB1, CB2, GPR55, and non-specific ion receptor protein transporters TRPs. First, we found up-regulated CNR1, GPR55, and TRPV1 expression in glioma patient-derived tissue samples and cell lines compared with non-malignant brain samples. CNR1 and GPR55 did not correlate with glioma grade, whereas TRPV1 negatively correlated with grade and positively correlated with longer overall survival. This suggests a tumour-suppressor role of TRPV1. With respect to markers of GBM stem cells, preferred targets of therapy, TRPV1 and GPR55, but not CNR1, strongly correlated with different sets of stemness gene markers: NOTCH, OLIG2, CD9, TRIM28, and TUFM and CD15, SOX2, OCT4, and ID1, respectively. This is in line with the higher expression of TRPV1 and GPR55 genes in GSCs compared with differentiated GBM cells. Second, in a panel of patient-derived GSCs, we found that CBG and CBD exhibited the highest cytotoxicity at a molar ratio of 3:1. We suggest that this mixture should be tested in experimental animals and clinical studies, in which currently used Δ9-tetrahydrocannabinol (THC) is replaced with efficient and non-psychoactive CBG in adjuvant standard-of-care therapy.
Keywords: glioblastoma, glioma, cannabigerol, cannabidiol, cannabinoid receptors, stem cells
Published in DiRROS: 18.07.2024; Views: 273; Downloads: 185
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1224. A small bacteriophage protein determines the hierarchy over co-residential jumbo phage in Bacillus thuringiensis serovar israelensisAnja Pavlin, Anže Lovše, Gregor Bajc, Jan Otoničar, Amela Kujović, Živa Lengar, Ion Gutiérrez-Aguirre, Rok Kostanjšek, Janez Konc, Nadine Fornelos, Matej Butala, 2022, original scientific article Abstract: Bacillus thuringiensis serovar israelensis is the most widely used biopesticide against insects, including vectors of animal and human diseases. Among several extrachromosomal elements, this endospore-forming entomopathogen harbors two bacteriophages: a linear DNA replicon named GIL01 that does not integrate into the chromosome during lysogeny and a circular-jumbo prophage known as pBtic235. Here, we show that GIL01 hinders the induction of cohabiting prophage pBtic235. The GIL01-encoded small protein, gp7, which interacts with the host LexA repressor, is a global transcription regulator and represses the induction of pBtic235 after DNA damage to presumably allow GIL01 to multiply first. In a complex with host LexA in stressed cells, gp7 down-regulates the expression of more than 250 host and pBtic235 genes, many of which are involved in the cellular functions of genome maintenance, cell-wall transport, and membrane and protein stability. We show that gp7 homologs that are found exclusively in bacteriophages act in a similar fashion to enhance LexA’s binding to DNA, while likely also affecting host gene expression. Our results provide evidence that GIL01 influences both its host and its co-resident bacteriophage.
Published in DiRROS: 18.07.2024; Views: 270; Downloads: 216
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1225. Genome-informed design of a LAMP assay for the specific detection of the strain of ‘Candidatus Phytoplasma asteris’ phytoplasma occurring in grapevines in South AfricaŠpela Alič, Marina Dermastia, Johan Burger, Matthew Dickinson, Gerhard Pietersen, Gert Pietersen, Tanja Dreo, 2022, original scientific article Abstract: Grapevine yellows is one of the most damaging phytoplasma-associated diseases worldwide. It is linked to several phytoplasma species, which can vary regionally due to phytoplasma and insect-vector diversity. Specific, rapid, and reliable detection of the grapevine yellows pathogen has an important role in phytoplasma control. The purpose of this study was to develop and validate a specific loop-mediated isothermal amplification (LAMP) assay for detection of a distinct strain of grapevine ‘Candidatus Phytoplasma asteris’ that is present in South Africa, through implementation of a genome-informed test design approach. Several freely available, user-friendly, web-based tools were coupled to design the specific LAMP assays. The criteria for selection of the assays were set for each step of the process, which resulted in four experimentally operative LAMP assays that targeted the ftsH/hflB gene region, specific to the aster yellows phytoplasma strain from South Africa. A real-time PCR was developed, targeting the same genetic region, to provide extensive validation of the LAMP assay. The validated molecular assays are highly specific to the targeted aster yellows phytoplasma strain from South Africa, with good sensitivity and reproducibility. We show a genome-informed molecular test design and an efficient validation approach for molecular tests if reference and sample materials are sparse and hard to obtain.
Keywords: aster yellows, fruit, LAMP, molecular detection, pathogendetection, phytoplasma, Prokaryotes
Published in DiRROS: 17.07.2024; Views: 281; Downloads: 178
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1226. Where and how : new insight for brown algal forest restoration in the AdriaticMartina Orlando-Bonaca, Gilda Savonitto, Valentina Asnaghi, Domen Trkov, Valentina Pitacco, Milijan Šiško, Tihomir Makovec, Petra Slavinec, Ana Lokovšek, Saul Ciriaco, Mariachiara Chiantore, Sara Kaleb, Emmanuelle Patricia Descourvières, Marina Srijemsi, Annalisa Falace, 2022, original scientific article Abstract: Several anthropogenic factors are responsible for the decline of Cystoseira sensu lato (hereafter Cystoseira) forests along Mediterranean coasts. Some Cystoseira species are already regionally extinct, and their decline has been widely recorded. Sustainable and efficient techniques for the restoration of Cystoseira are needed. In this context, the objectives of this study were i) to analyse the reproductive traits of three populations of Gongolaria barbata from three nearby donor sites in the northern Adriatic Sea, assessing the differences in their reproductive potential and reproductive success; and ii) to evaluate the outplanting success in terms of the effectiveness of G. barbata restoration, in relation to the different donor and receiving sites (Miramare MPA and in front of the Marine Biology Station Piran - MBSP) and implemented methods (ex situ and hybrid method combining a mesocosm cultivation and a suspended culture in the field). After 2 weeks of cultivation in mesocosms, half of the tiles with germlings were transported to the receiving sites and placed on suspended lantern nets (hybrid method), which were later (after 3 months) transferred to the seabed on concrete plates with protective cages. The remaining tiles were placed on the seabed on concrete plates with protective cages after a 4-week culture (ex situ method). At both sites, lantern nets and plates were randomly placed at 3 m depth. Thallus length was measured monthly in each treatment. Seedlings in suspended culture showed lower performance at the Miramare MPA, most likely due to the unfavourable environmental conditions. The satisfactory results obtained at MBSP demonstrate the efficiency of the hybrid method and confirm its potential to reduce the cost and time required for cultivation. Since unpredictable climatic events pose the greatest threat to restoration performance, these challenges must be considered when establishing new restoration practices. Moreover, herbivore regulation is extremely urgent and should be planned and implemented on a larger regional scale.
Keywords: canopy-forming algae, restoration, ex situ, cultivation, Mediterranean Sea
Published in DiRROS: 17.07.2024; Views: 297; Downloads: 80
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1227. Assessment of different experimental setups to determineviral filtration efficiency of face masksArijana Filipić, Katja Fric, Maja Ravnikar, Polona Kogovšek, 2022, original scientific article Abstract: Abstract
As a result of the COVID-19 pandemic, many new materials and masks came onto the market. To determine their suitability, several standards specify which properties to test, including bacterial filtration efficiency (BFE), while none describe how to determine viral filtration efficiency (VFE), a property that is particularly important in times of pandemic. Therefore, we focused our research on evaluating the suitability and efficiency of different systems for determining VFE. Here, we evaluated the VFE of 6 mask types (e.g., a surgical mask, a respirator, material for mask production, and cloth masks) with different filtration efficiencies in four experimental setups and compared the results with BFE results. The study included 17 BFE and 22 VFE experiments with 73 and 81 mask samples tested, respectively. We have shown that the masks tested had high VFE (>99% for surgical masks and respirators, ≥98% for material, and 87–97% for cloth masks) and that all experimental setups provided highly reproducible and reliable VFE results (coefficient of variation < 6%). Therefore, the VFE tests described in this study can be integrated into existing standards for mask testing.
Keywords: face masks, virus filtration efficiency, bacterial filtration efficiency, EN 14683:2019+AC:2019, air sampler
Published in DiRROS: 17.07.2024; Views: 285; Downloads: 167
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1228. Trace metals and polycyclic aromatic hydrocarbons in the Eastern Mediterranean sediments : concentration ranges as a tool for quality control of large data collectionsMarina Lipizer, Branko Čermelj, 2022, original scientific article Abstract: Assessing the status of marine pollution at regional and sub-regional scales requires the use of comparable and harmonized data provided by multiple institutions, located in several countries. Standardized data management and quality control are crucial for supporting a coherent evaluation of marine pollution. Taking the Eastern Mediterranean Sea as a case study, we propose an approach to improve the quality control procedures used for sediment pollution data, thus supporting a harmonized environmental assessment. The regional ranges of contaminant concentrations in sediments were identified based on an in-depth literature review, and the lowest measured concentrations were evaluated to determine the “background concentrations” of chemical substances not yet targeted in the Mediterranean Sea. In addition, to verify the suitability of the approach for validating large data collections provided by multiple sources, the determined ranges were used to validate a regional dataset available through EMODnet data infrastructure.
Published in DiRROS: 17.07.2024; Views: 237; Downloads: 146
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1229. Soil water dynamics and olive yield (Olea europaea L.) under different surface drip irrigation treatments in northern MediterraneanMatic Noč, Urša Pečan, Marina Pintar, Maja Podgornik, 2024, original scientific article Abstract: The use of modern irrigation systems and monitoring of soil water status can help improve crop performance and water use efficiency. The influence of different irrigation treatments on soil water content dynamics and olive oil yield was studied over two growing seasons using a surface drip irrigation system in an olive grove in northern Mediterranean climate. Irrigation treatments included optimal irrigation, sustained deficit irrigation (33 % of optimal irrigation), and rainfed treatment. Based on the water applied, we calculated the percentage of replenished estimated evapotranspiration (ETc*) for each treatment using the Penman-Monteith method. Soil water content dynamics were monitored with capacitive probes at five depths (10 to 50 cm). The increase in soil water content at a depth of 30 to 50 cm, which was only achieved with optimal irrigation, resulted in a significantly higher olive oil yield. In contrast, deficit irrigation, despite the addition of water, did not lead to an increase in soil water in the layers below 30 cm, so that the yield was equal to that of rainfed treatment. In irrigated olive groves, it is beneficial to monitor the water content of the soil at several depths to ensure that a sufficient amount of water has been applied.Uporaba sodobnih namakalnih sistemov ter spremljanje stanja vode v tleh lahko pripomore k izboljšanju učinkovitosti rastlinske pridelave in rabe vode. Vpliv različnih načinov namakanja na dinamiko vsebnosti vode v tleh in pri-delek oljčnega olja smo preučevali v dveh rastnih dobah z upo-rabo površinskega kapljičnega namakalnega sistema v oljčnem nasadu v severnem sredozemskem podnebju. Obravnavanja so vključevala optimalno namakanje, trajno namakanje s priman-jkljajem (33 % optimalnega namakanja) in brez namakanja. Na podlagi porabljene vode smo z uporabo metode Penman-Mon-teith izračunali odstotek nadomeščene ocenjene evapotranspi-racije (ETc*) za vsako obravnavo. Dinamiko vsebnosti vode v tleh smo spremljali s kapacitivnimi merilniki na petih globinah (od 10 do 50 cm). Povečanje vsebnosti vode v tleh na globini od 30 do 50 cm, ki je bilo doseženo le z optimalnim namakanjem, je povzročilo večji pridelek oljčnega olja. Nasprotno pa se pri namakanju s primanjkljajem kljub dodajanju vode ni povečala količina vode v tleh v plasteh pod 30 cm, zato je bil pridelek enak pridelku brez namakanja. V namakanih oljčnih nasadih je koristno spremljati vsebnost vode v tleh na več globinah, da se zagotovi, da je bila priskrbljena zadostna količina vode
Keywords: diviner, evapotranspiration, irrigation management, olive, soil depths, volumetric soil water content
Published in DiRROS: 17.07.2024; Views: 239; Downloads: 248
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1230. Learning deep representations of enzyme thermal adaptationGang Li, Filip Buric, Jan Zrimec, Sandra Viknander, Jens Nielsen, Aleksej Zelezniak, Martin K. M. Engqvist, 2022, original scientific article Abstract: Temperature is a fundamental environmental factor that shapes the evolution of organisms. Learning thermal determinants of protein sequences in evolution thus has profound significance for basic biology, drug discovery, and protein engineering. Here, we use a data set of over 3 million BRENDA enzymes labeled with optimal growth temperatures (OGTs) of their source organisms to train a deep neural network model (DeepET). The protein-temperature representations learned by DeepET provide a temperature-related statistical summary of protein sequences and capture structural properties that affect thermal stability. For prediction of enzyme optimal catalytic temperatures and protein melting temperatures via a transfer learning approach, our DeepET model outperforms classical regression models trained on rationally designed features and other deep-learning-based representations. DeepET thus holds promise for understanding enzyme thermal adaptation and guiding the engineering of thermostable enzymes.
Keywords: bioinformatics, deep neural networks, enzyme catalytic temperatures, optimal growth temperatures, protein thermostability, transfer learning
Published in DiRROS: 17.07.2024; Views: 298; Downloads: 200
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