Search results for "Lability"
showing 10 items of 802 documents
Insensitivity of Tree-Ring Growth to Temperature and Precipitation Sharpens the Puzzle of Enhanced Pre-Eruption NDVI on Mt. Etna (Italy)
2017
On Mt. Etna (Italy), an enhanced Normalized Difference in Vegetation Index (NDVI) signature was detected in the summers of 2001 and 2002 along a distinct line where, in November 2002, a flank eruption subsequently occurred. These observations suggest that pre-eruptive volcanic activity may have enhanced photosynthesis along the future eruptive fissure. If a direct relation between NDVI and future volcanic eruptions could be established, it would provide a straightforward and low-cost method for early detection of upcoming eruptions. However, it is unclear if, or to what extent, the observed enhancement of NDVI can be attributed to volcanic activity prior to the subsequent eruption. We conse…
New geo-portal for MODIS/SEVIRI image products with geolocation-based retrieval functionality
2015
A large number of remote sensing data sets have been collected in recent years by Earth observation instruments such as the moderate resolution imaging spectroradiometer (MODIS) aboard the Terra/Aqua satellite and the spinning enhanced visible and infrared imager (SEVIRI) aboard the geostationary platform Meteosat Second Generation. The advanced remote sensing products resulting from the analysis of these data are useful in a wide variety of appli- cations but require significant resources in terms of storage, retrieval, and analysis. Despite the wide availability of these MODIS/SEVIRI products, the data coming from these instruments are spread among different locations and retrieved from d…
Ecotoxicity assessment of boreal lake sediments affected by metal mining: Sediment quality triad approach complemented with metal bioavailability and…
2019
Highlights • Ecological risk assessment of metal-contaminated boreal lakes and sediments. • Sediment Quality Triad complemented with bioavailability and body residue studies. • Toxicity studies for natural sediments with several organisms and endpoints • Adverse effects observed. High variation on results between different methods. • Standard toxicity tests not suitable for testing, too low pH hampers the results. There are several methods for studying metal-contaminated freshwater sediments, but more information is needed on which methods to include in ecological risk assessment. In this study, we compliment the traditional Sediment Quality Triad (SQT) approach – including information on c…
Assessment of bioavailability and effects of chemicals due to remediation actions with caging mussels (Anodonta anatina) at a creosote-contaminated l…
2002
A study was conducted at Lake Jämsänvesi in Central Finland, to identify the potential ecotoxicological risks of the remediation operation of a creosote-/PAH-contaminated lake sediment, made by capping during the years 1998-1999. Mussels (Anodonta anatina) were deployed to the lake at the same time as the remediation operation was started in November 1998. The contaminated area (0.5 ha) was covered by a filter geotextile (polypropylene), gravel and sand (1-1.5m) which were spread out on the ice and let to sink onto the bottom of the lake when the ice melted in May 1999. The possible impacts of capping to the adjacent environment were assessed from mussels exposed and particulate material se…
Effects of Activated Carbon on PCB Bioaccumulation and Biological Responses of Chironomus riparius in Full Life Cycle Test
2016
The nonbiting midge Chironomus riparius was used to study the remediation potential and secondary effects of activated carbon (AC, ø 63-200 μm) in PCB contaminated sediments. AC amendments efficiently reduced PCB bioavailability determined by Chironomus riparius bioaccumulation tests and passive samplers. PCBs were shown to transfer from larvae to adults. Lower PCB concentrations were observed in adult midges emerging from AC amended compared to unamended sediments. Increased reproduction, survival, larval growth and gut wall microvilli length were observed with low AC dose (0.5% sediment dw) compared to unamended sediment, indicating an improved success of larvae in the sediment with low o…
Assessment of the bioactivity of creosote-contaminated sediment by liver biotransformation system of rainbow trout.
1999
A sediment site in the Lake Jamsanvesi (municipality of Petajavesi, Finland) contaminated by creosote was investigated to assess the possible ecotoxicological risks it may cause to benthic animals, including ones which may arise due to physical measures in remediating the site. It is suggested that polycyclic aromatic hydrocarbons (PAHs) are bioavailable to fish and other aquatic animals during exposure to contaminated water, sediment, and food. In order to assess toxicological risks of sediment contents to fish, juvenile rainbow trout (Onchorhynchus mykiss) were intraperitoneally dosed with extracts of the creosote-contaminated sediments and their elutriates. This was compared to pristine …
Toxicokinetics, toxicity and lethal body residues of two chlorophenols in the oligochaete worm, Lumbriculus variegatus, in different sediments
2003
Bioavailability, toxicokinetics and toxicity (LC(50)) of water- and sediment-associated 2,4,5-trichlorophenol (2,4,5-TCP) and pentachlorophenol (PCP) were measured in Lumbriculus variegatus Müller in a set of experiments. The critical body residue approach was applied by measuring also the lethal body residues (LBR(50)). Freshwater and three different sediments with various sediment organic carbon (SOC) concentrations were used as exposure media. SOC decreased the bioavailability of both chlorophenols, and the uptake rates decreased by 81% and 91% for 2,4,5-TCP and PCP, respectively, in the sediment with a SOC of 6.9% compared to those in sediment with a SOC of 0.5%. SOC appeared to be an i…
Accumulation of trace metals in sediments in a Mediterranean Lagoon: Usefulness of metal sediment fractionation and elutriate toxicity assessment.
2015
International audience; The authors investigated sediment quality in Bizerte Lagoon (Tunisia) focusing on geochemical characteristics, metal sediment fractionation and elutriate toxicity assessment. Nickel, Cu, Zn, Pb, Cr and Cd partitioning in sediments was studied; accumulation and bioavailability were elucidated using enrichment factors, sequential extractions, redox potential, acid volatile sulfide and biotest procedures in toxicity evaluation. Results revealed an accumulation for Pb and Zn, reaching 99 and 460 mg kg−1 respectively. In addition, the acid volatile sulfide values were high in both eastern and western lagoon areas, thus affecting metal availability. Mean enrichment factor …
BIOAVAILABILITY TO JUVENILE RAINBOW TROUT (ONCORYNCHUS MYKISS) OF RETENE AND OTHER MIXED-FUNCTION OXYGENASE-ACTIVE COMPOUNDS FROM SEDIMENTS
2002
Retene (7-isopropyl-1-methylphenanthrene) is a naturally formed polycyclic aromatic hydrocarbon (PAH) that causes teratogenicity in fish larvae and induction of cytochrome P450 (CYP1A) enzymes. Retene occurs at high concentrations (or =3,300 microg/g dry wt) in surface sediments contaminated by resin acids from pulp mill effluents. To assess the environmental risks of retene, it is important to evaluate conditions affecting its bioavailability and accumulation by fish. Fingerling rainbow trout were exposed to retene-spiked or naturally contaminated sediments and sampled after 4 d to determine liver CYP1A activity and concentrations of retene metabolites in bile as indicators of retene accum…
IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update
2018
In 2014, the IOC published a consensus statement entitled ‘Beyond the Female Athlete Triad: Relative Energy Deficiency in Sport (RED-S)’. The syndrome of RED-S refers to ‘impaired physiological functioning caused by relative energy deficiency and includes, but is not limited to, impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis and cardiovascular health’. The aetiological factor of this syndrome is low energy availability (LEA).1 The publication of the RED-S consensus statement stimulated activity in the field of Female Athlete Triad science, including some initial controversy2 3 followed by numerous scientific publications addressing: 1. The health…