Search results for "CLASSIFICATION"
showing 10 items of 29475 documents
Terrestrial Inputs Drive Seasonality in Organic Matter and Nutrient Biogeochemistry in a High Arctic Fjord System (Isfjorden, Svalbard)
2020
Climate-change driven increases in temperature and precipitation are leading to increased discharge of freshwater and terrestrial material to Arctic coastal ecosystems. These inputs bring sediments, nutrients and organic matter (OM) across the land-ocean interface with a range of implications for coastal ecosystems and biogeochemical cycling. To investigate responses to terrestrial inputs, physicochemical conditions were characterized in a river- and glacier-influenced Arctic fjord system (Isfjorden, Svalbard) from May to August in 2018 and 2019. Our observations revealed a pervasive freshwater footprint in the inner fjord arms, the geochemical properties of which varied spatially and seaso…
Temperature effects explain continental scale distribution of cyanobacterial toxins
2018
Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect…
Influence of Nanoparticle Exposure on Nervous System Development in Zebrafish Studied by Means of Light Sheet Fluorescence Microscopy
2016
Zebrafish has a remarkable similarity in the molecular signaling processes, cellular structure, anatomy and physiology to other higher order vertebrates, making it an excellent vertebrate model organism (1). Recently, zebrafish has been used for neurotoxicity screening of numerous nanomaterials with a focus on the developmental effects due to the possibility of in vivo visualization of specific neurons and axon tracts by injecting dyes in live animals as well in fixed ones (2). Here we propose Light Sheet Fluorescence Microscopy (LSFM) (3) (4) to perform neurotoxicity studies, in order to study the nervous system architecture and to image 3D structures in the brain of live larvae during the…
Difficulty of getting accurate and precise estimates of population size: The case of the Siberian flying squirrel in Finland
2008
Accurate estimates of population size and distribution are a prerequisite for effective management of populations, but for most species a reliable estimation of the absolute population size is very difficult. In 1998, the Finnish Ministry of Environment set up a working group to plan a national-level survey for estimation and monitoring of the population size of Siberian flying squirrel (Pteromys volans). In 2006, the population size was reported to be 143 000 females. However, evaluation of the magnitude of possible biases was not attempted. Our aim was to test the population size estimate by conducting a resampling study with the methods of the national survey on an eartagged population o…
Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples
2011
Hollow fiber liquid phase micro-extraction (LPME) of linear alkylbenzene sulfonates (LAS) from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM). Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sa…
Lipodepsipeptides from Pseudomonas syringae are partially proteolyzed and are not absorbed by humans: An in vitro study
2008
There are some concerns about the use of Pseudomonas-based products as biocontrol agents because of the hemolytic activity shown by their metabolites. The effects of Pseudomonas lipodepsipeptides (LDPs) on mammals via ingestion and the LDP degradation during the digestion and intestinal permeability have not been evaluated. In this research, the susceptibility of different LDPs to degradation was assayed with enzymatic gastrointestinal digestion, and intestinal permeability to LDPs was investigated in an in vitro system based on an intestinal cell layer system. Results demonstrated that trypsin and chymotrypsin hydrolyze up to 50% of the various LDPs, and that proteolysis was further increa…
Comparison between Citral and Pompia Essential Oil Loaded in Phospholipid Vesicles for the Treatment of Skin and Mucosal Infections
2020
Citrus species extracts are well known sources of bio-functional compounds with health-promoting effects. In particular, essential oils are known for their antibacterial activity due to the high content of terpenes. In this work, the steam-distilled essential oil from the leaves of Citrus limon var. pompia was loaded in phospholipid vesicles. The physico-chemical characteristics of the essential oil loaded vesicles were compared with those of vesicles that were loaded with citral, which is one of the most abundant terpenes of Citrus essential oils. The biocompatibility of the vesicles was assessed in vitro in human keratinocytes. Furthermore, the antimicrobial activity of the vesicles was t…
Selection of Membrane RNA Aptamers to Amyloid Beta Peptide: Implications for Exosome-Based Antioxidant Strategies
2019
The distribution of amyloid beta peptide 42 (Aβ42) between model exosomal membranes and a buffer solution was measured. The model membranes contained liquid-ordered regions or phosphatidylserine. Results demonstrated that up to ca. 20% of amyloid peptide, generated in the plasma (or intracellular) membrane as a result of proteolytic cleavage of amyloid precursor proteins by β- and γ-secretases, can stay within the membrane milieu. The selection of RNA aptamers that bind to Aβ42 incorporated into phosphatidylserine-containing liposomal membranes was performed using the selection-amplification (SELEX) method. After eight selection cycles, the pool of RNA aptamers was isol…
Exploring Bioequivalence of Dexketoprofen Trometamol Drug Products with the Gastrointestinal Simulator (GIS) and Precipitation Pathways Analyses
2019
The present work aimed to explain the differences in oral performance in fasted humans who were categorized into groups based on the three different drug product formulations of dexketoprofen trometamol (DKT) salt&mdash
Vendace (Coregonus albula) Disperse Their Eggs Widely during Spawning
2021
Depending on their reproductive strategy, different fish species either aggregate or disperse eggs and larvae in their reproductive habitat. Because yolk-sac larvae of vendace (Coregonus albula) disperse widely across the littoral and pelagic zones of boreal lakes, it is unclear where the exact spawning and egg incubation locations are. Vendace egg and larvae densities were studied in Lake Southern Konnevesi to clarify its spawning strategy. In autumn 2019, 1–2 weeks prior to spawning, 500 egg samplers were installed in five depth zones in 20 sampling plots. Fertilized eggs were found in 18 plots. The mean density of eggs was 74 eggs m–2 and the mean fertilization rate 85%. During spawning,…