Search results for "Systematic"
showing 10 items of 7608 documents
Migrations of hatchling European pond turtles (Emys orbicularis) after nest emergence
2013
Distances between nest sites of Emys orbicularis and the nearest water bodies can be long. We studied whether a longer distance could affect the probability of hatchling survival, migration time, and body mass loss. In our research area (Lubuskie district, western Poland), nest sites were situated on a slope; the closest water body was in a distance of 72-290 m. Near the water body we constructed a 550 m long drift fence to recapture hatchlings migrating down the slope. We monitored 32 hatchlings from 7 different nests deposited in the years 2008-2010. The hatchlings started to emerge from their nests on 9 and 13 April 2009, 7 and 9 April 2010, 30 March, 7 and 8 April 2011. Then, hatchlings…
Pseudo-diel vertical migration in zooplankton: a whole-lake 15N tracer experiment
2012
Diel vertical migration (DVM) of zooplankton is commonly considered an adaptation for feeding in food-rich and warm surface waters at night and avoiding visual predators during the day. However, the critical assessment of migration patterns frequently suggests that: (i) zooplankton may leave deeper waters with rich, deepchlorophyll layers and move into the epilimnion where food resources are lower and/or (ii) the night-time increase in epilimnetic plankton abundance is not matched by a density decrease in deeper strata. To study these discrepancies, we measured DVM of zooplankton in a 1.3-ha Spanish karst lake (Laguna del Tejo) where the phytoplankton in the deep chlorophyll layer had been …
Vertical diversity of bacteria in an oxygen-stratified humic lake, evaluated using DNA and phospholipid analyses
2009
Microbes play a particularly important role in the food web in lakes with high dissolved organic carbon content. The bacterial community of a polyhumic lake, Mekkojarvi, was studied using DNA techniques and phospholipid fatty acid (PLFA) analysis during the mid-summer period of water column strati- fication. According to the 16S rRNA gene clone libraries and length heterogeneity analysis (LH-PCR), heterotrophic bacteria dominated only in the oxic epilimnion, in which various Actinobacteria (mostly cluster acI-B) and Betaproteobacteria (especially Poly- nucleobacter subcluster PnecC) were common. Se- quences assigned to heterotrophic, methylotrophic, photoautotrophic, and chemoautotrophic ge…
Parasite-induced change in host behaviour and susceptibility to predation in an eye fluke–fish interaction
2004
Abstract Trophically transmitted parasites may increase their transmission efficiency by altering the behaviour of infected hosts to increase their susceptibility to predation by target hosts (the next host in the life cycle). The parasite Diplostomum spathaceum (Trematoda) reduces the vision of its fish intermediate hosts: its metacercariae lodge themselves in the eyes of fish and induce cataract formation, which gives them the opportunity to affect fish behaviour. We examined whether D. spathaceum eye flukes change the preference of fish for the surface layers of the water column or their escape behaviour, which could make the fish more vulnerable to predation by bird hosts. We also studi…
Effects of vegetation at different succession stages on soil properties and water flow in sandy soil
2015
The effects of vegetation at different succession stages on soil properties and water flow were assessed in sandy soil at 3 experimental sites near Sekule village (southwest Slovakia). Site S1 was a pioneer site dominated by mosses, site S2 was an early successional stage with a thin stand of grasses, and site S3 was an early successional stage (more advanced compared to the previous), richer in species, with a denser stand of grasses. It was found that vegetation at different succession stages affected soil properties and water flow in sandy soil, but the order of changes in some soil properties and water penetration depths were different from the order of succession stages.
Recognition of water masses according to geochemical signatures in the Central Mediterranean sea: Y/Ho ratio and rare earth element behaviour
2007
This study reports the results of geochemical investigations carried out in the Strait of Sicily (Central Mediterranean Sea) during the oceanographic cruise BANSIC 2000, focusing on the area around the Pantelleria Island. We evaluate the interface processes between dissolved phase and suspended particulate matter in the water columns on the basis of Y/Ho ratio and rare earth elements and yttrium distributions that are suitable to trace the occurrence of different water layers in Central Mediterranean Area. The main source of trace elements to the sea water system was recognized in the atmospheric fallout, while different scavenging mechanisms among Y and rare earth elements occur. Cation ex…
Long-term recovery of stream habitat structure and benthic invertebrate communities from in-stream restoration
2002
Headwater streams channelized for water transport of timber in Finland are being restored to their pre-channelization state. The primary motivation is the enhancement of sport fisheries, but restoration probably has profound impacts also on other stream organisms. We assessed how such ‘‘single-goal’’ restorations affect benthic macroinvertebrate communities. We revisited the streams sampled by Laasonen et al. [Aquatic Conservation: Marine and Freshwater Ecosystems 8 (1998)] in the early 1990s when the streams had been recently restored. In 1997, the recovery period of these streams ranged from 4 to 8 years. Habitat structure among the stream types represented a distinct recovery gradient, w…
Improving stock unearthing method to measure soil erosion rates in vineyards
2018
Abstract Vineyard soils experience high erosion rates compared to soils from other agricultural land uses. The high soil losses in vineyards limits the sustainability of traditional production schemes and warrants comprehensive research aimed at thwarting the main erosion processes affecting vineyard systems. However, long-term measurements, which include spatial variability of soil erosion rates at the plot scale, are uncommon, as most of the measurements have taken place either at the hillslope or watershed scales. Against this background, the stock unearthing method (SUM) can be considered a useful methodology. However, the current method falls short because it assumes that the topograph…
Crystalline wax coverage of the imaginal cuticle inCalopteryx splendens(Odonata: Calopterygidae)
2009
Abstract In this study we use high resolution SEM to describe the diversity of wax crystals and their distribution on different morphological structures in male individuals of Calopteryx splendens. The entire cuticle surface of this damselfly, with the exception of ommatidia and ocelli, is covered with crystalline wax in dimensions from submicron to micron range. It is shown that shape - rod-like, plate like, filamentous, etc. -, size, and density of crystals vary on different surfaces and in individuals of different ages. Additionally, we demonstrate different types of damage to the crystalline wax layer: scratches, compressions, wear, and contamination. The primary function of the wax cry…
Fracture Resistance of Partial Indirect Restorations Made With CAD/CAM Technology. A Systematic Review and Meta-analysis
2019
Background: The aim of this systematic review and meta-analysis was to determine the fracture resistance and survival rate of partial indirect restorations inlays, onlays, and overlays fabricated using computer-aided design and computer-aided manufacturing (CAD-CAM) technology from ceramics, composite resin, resin nanoceramic, or hybrid ceramic and to analyze the influence of proximal box elevation on fracture resistance. Materials and methods: This systematic review was based on guidelines proposed by the preferred reporting items for systematic reviews and meta-analyses (PRISMA). An electronic search was conducted in databases US National Library of Medicine National Institutes of Health …