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  • 1
    Online Resource
    Online Resource
    On the Predation of Doliolids (Tunicata, Thaliacea) on calanoid Copepods
    MDPI AG ; 2022
    In:  Journal of Marine Science and Engineering Vol. 10, No. 9 ( 2022-09-13), p. 1293-
    Details
    In: Journal of Marine Science and Engineering, MDPI AG, Vol. 10, No. 9 ( 2022-09-13), p. 1293-
    Abstract: The main goal of this contribution was to determine the effect of predation of the often abundant to dominant doliolid Dolioletta gegenbauri (Tunicata, Thaliacea) on the abundance of co-occurring planktonic copepods by feeding on their eggs. Previous oceanographic investigations revealed that doliolids had ingested eggs of small calanoid copepods. The ecological significance of such feeding could not be quantified completely because the environmental abundance of such eggs was not known. In this study, the eggs and nauplii of the neritic calanoid Paracalanus quasimodo (Crustacea, Copepoda) were offered to gonozooids and phorozooids of D. gegenbauri with a 6–6.5 mm length together with three species of phytoplankton; i.e., simulating diet conditions on the shelf. We hypothesized that copepod eggs of a similar size as food particles would be readily ingested whereas small nauplii, which could escape, would hardly be eaten by the doliolids. Our results revealed that doliolids have the potential to control small calanoids by ingesting their eggs at high rates but not their nauplii or later stages. Late copepodid stages and adults of co-occurring calanoid species could cause less mortality because they prey less on such eggs than doliolids of a similar weight. However, certain abundant omnivorous calanoid species with pronounced perception and/or capture abilities can prey successfully on the nauplii of small calanoids.
    Type of Medium: Online Resource
    ISSN: 2077-1312
    URL: Article
    DOI: 10.3390/jmse10091293
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2738390-8
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  • 2
    Online Resource
    Online Resource
    Modelling airborne transmission of SARS-CoV-2 at a local scale
    Public Library of Science (PLoS) ; 2022
    In:  PLOS ONE Vol. 17, No. 8 ( 2022-8-30), p. e0273820-
    Details
    In: PLOS ONE, Public Library of Science (PLoS), Vol. 17, No. 8 ( 2022-8-30), p. e0273820-
    Abstract: The coronavirus disease (COVID-19) pandemic has changed our lives and still poses a challenge to science. Numerous studies have contributed to a better understanding of the pandemic. In particular, inhalation of aerosolised pathogens has been identified as essential for transmission. This information is crucial to slow the spread, but the individual likelihood of becoming infected in everyday situations remains uncertain. Mathematical models help estimate such risks. In this study, we propose how to model airborne transmission of SARS-CoV-2 at a local scale. In this regard, we combine microscopic crowd simulation with a new model for disease transmission. Inspired by compartmental models, we describe virtual persons as infectious or susceptible. Infectious persons exhale pathogens bound to persistent aerosols, whereas susceptible ones absorb pathogens when moving through an aerosol cloud left by the infectious person. The transmission depends on the pathogen load of the aerosol cloud, which changes over time. We propose a ‘high risk’ benchmark scenario to distinguish critical from non-critical situations. A parameter study of a queue shows that the new model is suitable to evaluate the risk of exposure qualitatively and, thus, enables scientists or decision-makers to better assess the spread of COVID-19 and similar diseases.
    Type of Medium: Online Resource
    ISSN: 1932-6203
    URL: Article
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    DOI: 10.1371/journal.pone.0273820
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    Language: English
    Publisher: Public Library of Science (PLoS)
    Publication Date: 2022
    detail.hit.zdb_id: 2267670-3
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  • 3
    Online Resource
    Online Resource
    Toward learning dynamic origin-destination matrices from crowd density heatmaps
    IOP Publishing ; 2022
    In:  Journal of Statistical Mechanics: Theory and Experiment Vol. 2022, No. 5 ( 2022-05-01), p. 053401-
    Details
    In: Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, Vol. 2022, No. 5 ( 2022-05-01), p. 053401-
    Abstract: Knowing the origins and destinations of pedestrians’ paths is key to the initialization of crowd simulations. Unfortunately, they are difficult to measure in the real world. This is one major challenge for live predictions during events such as festivals, soccer games, protest marches, and many others. Sensor data can be used to feed real-world observations into simulations in real-time. As input data for this study, we use density heatmaps generated from real-world trajectory data obtained from stereo sensors. Density information is compact, of constant size, and in general easier to obtain than e.g., individual trajectories. Therefore, the information limitation improves the applicability to other scenarios. We include the absolute pedestrian trip counts from origins to destinations during a brief time interval in an OD matrix, including unknown destinations due to sensor errors. Our goal is to estimate these OD matrices from a series of density heatmaps for the same interval. For this, we compute the ground truth OD matrices and density heatmaps using real-world trajectory data from a train station. We employ linear regression as a statistical learning method for estimation. We observe that the linear share of the relationship between density and OD matrix is estimated successfully. Nevertheless, a portion of the data remains that cannot be explained. We attempt to overcome this difficulty with random forest as a nonlinear model. The results indicate that both a linear and a nonlinear model can estimate some features of the OD matrices. However, there is no clear winner in terms of the chosen metric, the R 2 score. Overall, our findings are a strong indicator that OD matrices can indeed be estimated from density heatmaps extracted automatically from sensors.
    Type of Medium: Online Resource
    ISSN: 1742-5468
    URL: Article
    DOI: 10.1088/1742-5468/ac6255
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2022
    detail.hit.zdb_id: 2138944-5
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  • 4
    Online Resource
    Online Resource
    Bayesian inference methods to calibrate crowd dynamics models for safety applications
    Elsevier BV ; 2022
    In:  Safety Science Vol. 147 ( 2022-03), p. 105586-
    Details
    In: Safety Science, Elsevier BV, Vol. 147 ( 2022-03), p. 105586-
    Type of Medium: Online Resource
    ISSN: 0925-7535
    URL: Article
    DOI: 10.1016/j.ssci.2021.105586
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 2021100-4
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  • 5
    Online Resource
    Online Resource
    Identification of Pri-miRNA Stem-Loop Interacting Proteins in Plants Using a Modified Version of the Csy4 CRISPR Endonuclease
    MDPI AG ; 2022
    In:  International Journal of Molecular Sciences Vol. 23, No. 16 ( 2022-08-11), p. 8961-
    Details
    In: International Journal of Molecular Sciences, MDPI AG, Vol. 23, No. 16 ( 2022-08-11), p. 8961-
    Abstract: Regulation at the RNA level by RNA-binding proteins (RBPs) and microRNAs (miRNAs) is key to coordinating eukaryotic gene expression. In plants, the importance of miRNAs is highlighted by severe developmental defects in mutants impaired in miRNA biogenesis. MiRNAs are processed from long primary-microRNAs (pri-miRNAs) with internal stem-loop structures by endonucleolytic cleavage. The highly structured stem-loops constitute the basis for the extensive regulation of miRNA biogenesis through interaction with RBPs. However, trans-acting regulators of the biogenesis of specific miRNAs are largely unknown in plants. Therefore, we exploit an RNA-centric approach based on modified versions of the conditional CRISPR nuclease Csy4* to pull down interactors of the Arabidopsis pri-miR398b stem-loop (pri-miR398b-SL) in vitro. We designed three epitope-tagged versions of the inactive Csy4* for the immobilization of the protein together with the pri-miR398b-SL bait on high affinity matrices. After incubation with nucleoplasmic extracts from Arabidopsis and extensive washing, pri-miR398b-SL, along with its specifically bound proteins, were released by re-activating the cleavage activity of the Csy4* upon the addition of imidazole. Co-purified proteins were identified via quantitative mass spectrometry and data sets were compared. In total, we identified more than 400 different proteins, of which 180 are co-purified in at least two out of three independent Csy4*-based RNA pulldowns. Among those, the glycine-rich RNA-binding protein AtRZ-1a was identified in all pulldowns. To analyze the role of AtRZ-1a in miRNA biogenesis, we determined the miR398 expression level in the atrz-1a mutant. Indeed, the absence of AtRZ-1a caused a decrease in the steady-state level of mature miR398 with a concomitant reduction in pri-miR398b levels. Overall, we show that our modified Csy4*-based RNA pulldown strategy is suitable to identify new trans-acting regulators of miRNA biogenesis and provides new insights into the post-transcriptional regulation of miRNA processing by plant RBPs.
    Type of Medium: Online Resource
    ISSN: 1422-0067
    URL: Article
    DOI: 10.3390/ijms23168961
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2019364-6
    SSG: 12
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  • 6
    Online Resource
    Online Resource
    Feeding of Marine Zooplankton on Microplastic Fibers
    Springer Science and Business Media LLC ; 2022
    In:  Archives of Environmental Contamination and Toxicology Vol. 83, No. 2 ( 2022-08), p. 129-141
    Details
    In: Archives of Environmental Contamination and Toxicology, Springer Science and Business Media LLC, Vol. 83, No. 2 ( 2022-08), p. 129-141
    Abstract: The goal of our study was to examine the effects of low abundances of nylon fibers on feeding rates of calanoid copepods (Crustacea, Copepoda) and doliolids (Tunicata, Thaliacea) in the presence of diatoms at near environmental concentration levels. In addition, we examined microscopically the fecal pellets produced by copepods and doliolids in the presence of fibers. Adult females of the calanoid Eucalanus pileatus and early gonozooids of Dolioletta gegenbauri (both of similar dry weight) cleared the diatom Rhizosolenia alata at similar rates. Nylon fibers were cleared at higher rates by Dolioletta gegenbauri compared to Eucalanus pileatus . Examination of fecal pellets revealed that copepods and doliolids could ingest the about 300 µm long fibers. The latter also ingested the occasionally occurring fibers of  〉  1 mm length. It appears that in seawater fiber abundances of about seven fibers ml −1 did not have a negative effect on feeding of either E. pileatus or D. gegenbauri . As doliolids and copepods remove plastic fibers from seawater by packing them into their pellets, they might play a role in the reduction of microplastic pollution and the microplastic transfer from the water column to the seafloor. Calanoid copepods may limit ingesting fibers by not perceiving them, as compared to doliolids which do not seem to be able to avoid ingesting them.
    Type of Medium: Online Resource
    ISSN: 0090-4341 , 1432-0703
    URL: Article
    DOI: 10.1007/s00244-022-00948-1
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 185986-9
    detail.hit.zdb_id: 1458449-9
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