Search results for "LK"
showing 10 items of 8438 documents
Evolution of yolk androgens in birds: development, coloniality and sexual dichromatism
2007
18 pages; International audience; Current theory recognizes the adaptive value of maternal effects in shaping offspring phenotypes in response to selective pressures and vindicates the value of these traits in fostering adaptation and speciation. Yolk androgens in birds are a relatively well-known maternal effect and have been linked to adaptations related to development, coloniality life, and sexual selection. We tested whether interspecific patterns of yolk androgen levels (androstenedione and testosterone) were related to interspecific variation in development, sexual selection, and coloniality. First, we found no relationship between androgen levels and duration of development as reflec…
From glacial refugia to hydrological microrefugia: Factors and processes driving the persistence of the climate relict tree Zelkova sicula
2021
Abstract With only two tiny populations, the climate relict Zelkova sicula (Sicily, Italy) is one of the rarest trees in the world. It also represents the most marginal member of genus Zelkova that was widespread in the broadleaved forests thriving in warm–temperate climates throughout Eurasia until the Last Glacial Age. Occurring at the westernmost range of the genus under typical Mediterranean climate, the micro‐topographic settings have always appeared crucial for the survival of this relict. However, the factors and processes actually involved in its persistence in the current refugia, as well as the response of similar relict trees in arid environments, are poorly understood worldwide.…
Does trait-based joint species distribution modelling reveal the signature of competition in stream macroinvertebrate communities?
2021
1. The occupancy and abundance of species are jointly driven by local factors, such as environmental characteristics and biotic interactions, and regional‐scale factors, such as dispersal and climate. Recently, it has been shown that biotic interactions shape species occupancies and abundances beyond local extents. However, for small ectothermic animals, particularly for those occurring in freshwater environments, the importance of biotic interactions remains understudied. Species‐to‐species associations from joint species distribution models (i.e. species associations while controlling for environmental characteristics) are increasingly used to draw hypotheses of which species possibly sho…
Ecological niche features override biological traits and taxonomic relatedness as predictors of occupancy and abundance in lake littoral macroinverte…
2018
The degree to which species ecological and biological traits determine their distribution and abundance has intrigued ecologists for a long time, and it has seen a revival in recent years. This topic is important because it provides information about the determinants of species rarity and their conservation implications. We examined the effects of niche breadth, niche position, biological traits and taxonomic relatedness on the interspecific occupancy–abundance relationship, as well as on occupancy and abundance, in lake littoral macroinvertebrates. We sampled 48 lakes in a boreal lake district, found altogether 155 species, and calculated regional occupancy (as the proportion of sites occu…
Poplar Biochar as an Alternative Substrate for Curly Endive Cultivated in a Soilless System
2020
Imminent necessity for eco-friendly and low-cost substitutes to peat is a defiance in the soilless plant cultivation systems. Wood biochar could entirely or partly substitute peat as a plant growing constituent to produce vegetables. Nevertheless, knowledge concerning potential plant performance of leafy green vegetables grown on wood biochar is restricted. The present study assessed the main physicochemical traits of various growing media constituted by decreasing the content of peat and by increasing the percentages of poplar wood biochar. Yield, nutritional and functional properties of curly endive plants cultivated in a protected environment were also tested. Biochar was pyrolyzed from …
Underwater high frequency noise: Biological responses in sea urchin Arbacia lixula (Linnaeus, 1758)
2020
Marine life is extremely sensitive to the effects of environmental noise due to its reliance on underwater sounds for basic life functions, such as searching for food and mating. However, the effects on invertebrate species are not yet fully understood. The aim of this study was to determine the biochemical responses of Arbacia lixula exposed to high-frequency noise. Protein concentration, enzyme activity (esterase, phosphatase and peroxidase) and cytotoxicity in coelomic fluid were compared in individuals exposed for three hours to consecutive linear sweeps of 100 to 200 kHz lasting 1 s, and control specimens. Sound pressure levels ranged between 145 and 160 dB re 1μPa. Coelomic fluid was …
RNA interference in Lepidoptera: an overview of successful and unsuccessful studies and implications for experimental design.
2011
International audience; Gene silencing through RNA interference (RNAi) has revolutionized the study of gene function, particularly in non-model insects. However, in Lepidoptera (moths and butterflies) RNAi has many times proven to be difficult to achieve. Most of the negative results have been anecdotal and the positive experiments have not been collected in such a way that they are possible to analyze. In this review, we have collected detailed data from more than 150 experiments including all to date published and many unpublished experiments. Despite a large variation in the data, trends that are found are that RNAi is particularly successful in the family Saturniidae and in genes involv…
A molecular-based identification resource for the arthropods of Finland
2022
Publisher Copyright: © 2021 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd. To associate specimens identified by molecular characters to other biological knowledge, we need reference sequences annotated by Linnaean taxonomy. In this study, we (1) report the creation of a comprehensive reference library of DNA barcodes for the arthropods of an entire country (Finland), (2) publish this library, and (3) deliver a new identification tool for insects and spiders, as based on this resource. The reference library contains mtDNA COI barcodes for 11,275 (43%) of 26,437 arthropod species known from Finland, including 10,811 (45%) of 23,956 insect species. To quantify the…
Alkaline phosphatase survey in pecorino siciliano PDO cheese
2021
The determination of alkaline phosphatase (ALP) in cheeses has become an official method for controlling cheeses with a protected designation of origin (PDO), all of which use raw milk. PDO cheeses, characterized by high craftsmanship, usually have an uneven quality. However, for these cheeses, it is necessary to establish ALP values so that they can be defined as a raw milk product. In this study, a dataset with Pecorino Siciliano PDO samples was analyzed to determine ALP both at the core and under the rind. The results showed that there was no significant difference between the different zones in Pecorino cheese. A second dataset of 100 pecorino cheese samples determined that ALP was only…
Local consumers are the first line to control biological invasions: a case of study with the whelk Stramonita haemastoma (Gastropoda: Muricidae)
2016
The increasing spread of invasive species in the Mediterranean Sea determines several alterations in local food webs, changing the feeding habits of native organisms. The whelk Stramonita haemastoma is a widespread Mediterranean gastropod that consumes bivalves, barnacles and limpets. Previous studies showed a shift in its diet from the bivalve Mytilaster minimus to the invasive mussel Brachidontes pharaonis, presumably due to a higher energy gain. Here we tested whelks’ preference among natives and a novel prey, calculating the profitability ratio, and integrating those results with biochemical analysis on prey tissues and the routine metabolism of the whelks. Further, we used the scaled f…