Search results for "TACE"
showing 10 items of 739 documents
Concreções calcárias da formação Santana, bacia do Araripe: uma proposta de classificação.
2007
18 pages; The calcareous concretions of the Santana Formation have been known since 1800 thanks to the work of João da Silva Feijó (1800). Their study was promoted internationally by the report of von Spix and von Martius (1823-1831), and their richness in fossil fishes led Silva Santos to name them “ichthyoliths” in 1950. Here we propose a classification for the various types of calcareous concretions that occurred in the Santana Formation (Late Cretaceous, Araripe Basin). We consider their geographic distribution and we propose a terminological uniformization for the descriptions of that material. This will serve future statistical, geographical, geochemical and taphonomical studies that,…
Turvemaiden maankäytön vaikutukset kuoriameebayhteisöihin
2013
Turvemaiden maankäytöllä on todettu olevan monenlaisia ympäristövaikutuksia, kuten esimerkiksi kasvihuoneilmiötä vauhdittavat kaasupäästöt (esim. CO2 & CH4), turvetuotannon vesistövaikutukset ja turpeenpolton päästöt. Lisäksi turvemaiden maankäytöllä on vahvoja vaikutuksia soihin. Maankäytön ympäristövaikutusten arvioinnissa on käytetty apuna monia eliöryhmiä, esimerkiksi pohjaeläimiä, eläinplanktonia ja kaloja. Kuoriameebat (Testacea) ovat ryhmä pieniä, lajistoltaan monimuotoisia ja laajalle levinneitä yksisoluisia eliöitä. Ne ovat pääasiallisesti akvaattisia eliöitä, ja niitä esiintyy muun muassa turvemailla, kosteikoissa ja järvissä. Kuoriameebat sopivat erityisesti turvemaassa tapahtuvi…
Enhanced Thin-Film Transistor Performance by Combining 13,6-N-Sulfinylacetamidopentacene with Printed PEDOT:PSS Electrodes
2011
Bottom-contact/bottom-gate organic thin-film transistors (OTFTs) are fabricated using a soluble pentacene precursor (13,6-N-sulfinylacetamidopentacene; SAP) and inkjet printed PEDOT:PSS electrodes on bare SiO2 dielectrics. Saturation mobility, Ion/Ioff ratio, and threshold voltage parameters, respectively, of 0.27 cm2 V−1 s−1, 105, and −4.25 V were measured under ambient conditions after the thermal conversion of SAP to pentacene in 100 μm long channel OTFT devices. The results obtained by the above solution approach are comparable to that of vapor-phase grown pentacene-based OTFTs with photolithographic gold contacts and organic buffer layers and/or inorganic injection layers. The present …
Quantification of cadmium-induced metallothionein in crustaceans by the silver-saturation method
1995
Metallothionein (MT) has been proposed as a specific biochemical probe for metal exposure of aquatic organisms. It is recognized that its usefulness as a monitoring tool depends on the full understanding of its function and on the possibility of measuring its concentration in tissues. Therefore the study of MT in crustaceans is interesting from two different points of view: the need to understand mechanisms associated with the toxicology of metals, and the potential use of this protein for monitoring metal-contamined environments. Several methods have been developed for quantitative measurements of MT in biological samples. Immunochemical and electrochemical procedures are reliable techniqu…
Population structure, life cycle, and trophic niche of the glacial relict amphipod, Gammaracanthus lacustris, in a large boreal lake
2019
Ecology of the glacial relict macrocrustacean Gammaracanthus lacustris, a rare inhabitant of deep Fennoscandian lakes, is poorly understood. We studied the life cycle and trophic position of this cold‐stenothermic amphipod in Lake Paasivesi, eastern Finland. The study is based on intensive sampling and analyses of fatty acid composition as well as stable carbon (δ13C) and nitrogen (δ15N) isotope ratios. Both day and night, the G. lacustris population occurred at depths below 25 m at temperatures 40 mm and live up to 4 years. The oldest and the largest individuals and females seemed to favour the deepest zones. In October, almost 100% of females with length at least 25 mm (i.e. females presu…
Preliminary study on the unusual properties in the habitat of Ranunculetum baudotii in Central Europe
2011
Abstract The study examines the patches of the saltwater association Ranunculetum baudotii in a new, atypical site; i.e., located more than 400 km away from the Baltic coastal line. They were found in a karst spring, and were the first locality of the community identified in Poland. The water and sediments within the patches were analyzed chemically in the laboratory, but, conductivity, water temperature and O2 content were measured in the field. The spring was determined to be a relatively stable aquatic habitat, with a typical chemical composition of subterranean water (a prevalence of hydro-carbonate, calcium and magnesium ions), and rich, e.g., in nitrogen and phosphorus, and disturbed …
Pyriproxyfen, a juvenoid hormone analog, does not induce male production in parthenogenetic lineages of Eucypris virens (Crustacea: Ostracoda)
2007
Analogs of juvenoid hormones are increasingly recommended for controlling insect pests in agriculture. One of these analogs, pyriproxyfen, was found to be very potent in inducing male production in Daphnia under laboratory conditions, even after acute exposure. Other studies also demonstrated a major role of juvenoid hormones for the sex determination in arthropods that have sex chromosomes. We exposed parthenogenetic lineages of the freshwater ostracod Eucypris virens to a wide range of pyriproxyfen concentrations, and compared mortality and fecundity between treated and control animals. Animals exposed to the highest concentrations of pyriproxyfen (3-30 nM) experienced a higher mortality …
Experimental test on the use of MS-222 for ostracod anaesthesia: concentration, immersion period and recovery time
2010
Anaesthesia of animals may be useful for different purposes, particularly for veterinary reasons or in experimental research, for manipulation or treatment of immobilized but alive animals. Its use in crustaceans is not uncommon, but it has never been described for Ostracoda. We provide brief and preliminary guidelines on the use of the tricaine mesylate (MS-222) on the widespread freshwater ostracod Eucypris virens and we show that this compound is an effective anaesthetic used as a bath treatment at minimum concentrations of 500 mg L-1. This value is considerably higher than that recommended for other aquatic animals like fish. Recovery time, ranging from 5 to 15 minutes, is mostly determ…
Comparative ultrastructure and carbohydrate composition of gastroliths from Astacidae, Cambaridae and Parastacidae freshwater crayfish (Crustacea, De…
2012
21 pages; International audience; Crustaceans have to cyclically replace their rigid exoskeleton in order to grow. Most of them harden this skeleton by a calcification process. Some decapods (land crabs, lobsters and crayfish) elaborate calcium storage structures as a reservoir of calcium ions in their stomach wall, as so-called gastroliths. For a better understanding of the cyclic elaboration of these calcium deposits, we studied the ultrastructure of gastroliths from freshwater crayfish by using a combination of microscopic and physical techniques. Because sugars are also molecules putatively involved in the elaboration process of these biomineralizations, we also determined their carbohy…
Dieta del delfín de Risso (Grampus griseus) en el Mediterráneo occidental
2006
DIETA DEL DELFÍN DE RISSO (GRAMPUS GRISEUS) EN EL MEDITERRÁNEO OCCIDENTAL. – Se ha analizado el contenido gastrointestinal de quince ejemplares de Grampus griseus varados en el Mediterráneo occidental entre 40º25’N 00º32’W y 37º35’N 00º45’E durante el período 1987 a 2003. Los resultados indican una dieta teutófaga, basada principalmente en cefalópodos oceánicos destacando los octópodos pelágicos, especialmente Argonauta argo, como la presa más abundante (media = 41,28%; SD±34,32). Algunas especies pertenecientes a las familias mmastrephidae, Histioteuthidae y Onychoteuthidae son también componentes frecuentes de la misma. La distribución batimétrica de los cefalópodos indica que el área de …