Search results for "Ala"
showing 10 items of 18976 documents
The effect of fish life-history structures on the topologies of aquatic food webs
2021
Biological organisms can vastly change their ecological functionality due to changes in body size and diet across their life. Consequently, it has been increasingly recognized that to attain sufficient biological realism, food webs may need to include life-history structures. The objective of the work is to study theoretically whether and how the inclusion of life-history structures affects the food web topology. Topological research was done by applying network theory metrics for three different food web types with two different sizes that were generated by using the niche-model. The dynamical modeling was performed by using an allometric trophic network modeling approach. The different ty…
In utero behavioral imprinting to predation risk in pups of the bank vole
2020
Abstract In the predator–prey arms race, survival-enhancing adaptive behaviors are essential. Prey can perceive predator presence directly from visual, auditory, or chemical cues. Non-lethal encounters with a predator may trigger prey to produce special body odors, alarm pheromones, informing conspecifics about predation risks. Recent studies suggest that parental exposure to predation risk during reproduction affects offspring behavior cross-generationally. We compared behaviors of bank vole (Myodes glareolus) pups produced by parents exposed to one of three treatments: predator scent from the least weasel (Mustela nivalis nivalis); scent from weasel-exposed voles, i.e., alarm pheromones;…
Bank vole alarm pheromone chemistry and effects in the field
2021
Chemical communication plays an important role in mammalian life history decisions. Animals send and receive information based on body odour secretions. Odour cues provide important social information on identity, kinship, sex, group membership or genetic quality. Recent findings show, that rodents alarm their conspecifics with danger-dependent body odours after encountering a predator. In this study, we aim to identify the chemistry of alarm pheromones (AP) in the bank vole, a common boreal rodent. Furthermore, the vole foraging efficiency under perceived fear was measured in a set of field experiments in large outdoor enclosures. During the analysis of bank vole odour by gas chromatograph…
Negative associations between parasite avoidance, resistance and tolerance predict host health in salmonid fish populations
2020
Genetic variation in defence against parasite infections is fundamental for host–parasite evolution. The overall level of defence of a host individual or population includes mechanisms that reduce parasite exposure (avoidance), establishment (resistance) or pathogenicity (tolerance). However, how these traits operate and evolve in concert is not well understood. Here, we investigated genetic variation in and associations between avoidance, resistance and tolerance in a natural host–parasite system. Replicated populations of Atlantic salmon ( Salmo salar ) and sea trout (an anadromous form of brown trout, Salmo trutta ) were raised under common garden conditions and infected with the eye fl…
The effects of different combinations of fixed and moving bed bioreactors on rainbow trout (Oncorhynchus mykiss) growth and health, water quality and…
2019
Abstract The effect of bioreactor design on nitrification efficiency has been well studied, but less is known about the overall impacts on water quality. Besides nitrification, submerged fixed bed bioreactors (FBBR) trap fine solid particles, whereas moving bed bioreactors (MBBR) grind solids, possibly increasing solids and particle accumulation in the system. In this experiment, the effects of different combinations of fixed bed and moving bed bioreactors on water quality, solids removal, particle size distribution, fish health based on histopathological changes and nitrification efficiency were studied in laboratory scale recirculating aquaculture systems (RAS) with rainbow trout (Oncorhy…
First record of <em>Arctodiaptomus wierzejskii</em> (Richard, 1888) (Copepoda Calanoida Diaptomidae) from Malta
2020
Diaptomid copepods belonging to the genus Arctodiaptomus Kiefer, 1932 were collected in two temporary water bodies in Malta. The morphological identification of the collected specimens proved that they belong to Arctodiaptomus wierzejskii (Richard, 1888) even if a morphological peculiarity pertaining to the morphology of the male right antennule of the Maltese populations was observed and here briefly discussed. This finding constitutes the first record of a calanoid copepod from the inland waters of the Maltese Islands.
Epibiontes en juveniles de tortugas carey Eretmochelys imbricata varadas en la costa del Departamento de Rocha, Uruguay
2016
The hawksbill turtle (Eretmochelys imbricata) is the most threatened sea turtle species in the world. An important aspect of the biology of sea turtles is the study of colonizing fauna, i.e., their epibiota. The aim of this study is a taxonomic determination on the epibiota found on 4 hawksbills turtles stranded in 2009 and 2011 on the coast of Rocha Department, Uruguay. The epibiota was composed by algae from the class Phaeophyceae (Sphacelaria sp. and Hincksia mitchelliae) and invertebrates from the classes Cirripedia (Platylepas hexastylos, Chelonibia testudinaria and Amphibalanus improvisus) and Hirudinea (Ozobranchus margoi), with greater predominance of P. hexastylos cirripeds (n= 365…
Evaluation of microbiological and physico‐chemical parameters of retail ready‐to‐eat mono‐varietal salads
2019
An integrated microbiological and physico-chemical approach was applied to evaluate the decay of mono-varietal ready-to-eat escarole (Cichorium endivia var. latifolium) and red chicory (Cichorium intybus L. var. foliosum Hegi) during refrigeration. Total mesophilic microorganisms, including pseudomonads, and total psychrotrophic microorganisms were detected at high numbers in all samples just after packaging and at the expiry date. The dominant microbial populations analyzed by classical culture-dependent methods belonged to Pseudomonas and yeasts. Illumina sequencing identified Janthinobacterium lividum and Pseudomonas veronii as main species. Regarding the physico-chemical quality between…
Cytotoxic polyoxygenated isopimarane diterpenoids from the edible rhizomes of Kaempferia galanga (kencur)
2020
Abstract Kaempferia galanga (Family Zingiberaceae) is a widely distributed Asian medicinal plant and cultured crop. Several traditional uses of the rhizomes of this plant have been reported with widely using as flavors and spice in cooking. The present work concerned the isolation and identification as well as antiproliferative activity of metabolites of the rhizomes of K. galanga. Three new polyoxygenated isopimarane diterpenoids, kaemgalangols B-D (1-3), were isolated and identified in addition to 20 knowns (4-27), one monoterpene (28), and five known phenolic compounds (29-33). The chemical structures of the isolated compounds were established mainly based upon the spectroscopic analysis…
Variation in leaf anatomical traits relates to the evolution of C4 photosynthesis in Tribuloideae (Zygophyllaceae)
2019
Abstract Tribuloideae (Zygophyllaceae, Zygophyllales) is a warm-climate clade of mostly creeping herbs with an uncertain number of C4 species from at least two genera, raising the possibility of multiple C4 origins within this lineage. To delineate C3 and C4 distributions within Tribuloideae, we conducted a phylogenetic analysis using four genetic markers from 78 accessions of Tribuloideae. δ13C values from 68 Tribuloideae members detected 42 C4 species in the genera Kallstroemia, Tribulopis and Tribulus, and no C4 in Balanites, Neoluederitzia, and Sisyndite. All Kallstroemia are C4, while Tribulopis and Tribulus include C3 species. Two independent C4 origins are supported, one in Tribulus …