Search results for "SPECIALIZATION"
showing 10 items of 134 documents
Gene expression is more strongly associated with behavioural specialization than with age or fertility in ant workers.
2018
The ecological success of social insects is based on division of labour, not only between queens and workers, but also among workers. Whether a worker tends the brood or forages is influenced by age, fertility and nutritional status, with brood carers being younger, more fecund and more corpulent. Here, we experimentally disentangle behavioural specialization from age and fertility in Temnothorax longispinosus ant workers and analyse how these parameters are linked to whole-body gene expression. A total of 3,644 genes were associated with behavioural specialization which is ten times more than associated with age and 50 times more than associated with fertility. Brood carers were characteri…
Morphological traits predict host-tree specialization in wood-inhabiting fungal communities
2020
Tree species is one of the most important determinants of wood-inhabiting fungal community composition, yet its relationship with fungal reproductive and dispersal traits remains poorly understood. We studied fungal communities (total of 657 species) inhabiting broadleaved and coniferous dead wood (total of 192 logs) in 12 semi-natural boreal forests. We utilized a trait-based hierarchical joint species distribution model to examine how the relationship between dead wood quality and species occurrence correlates with reproductive and dispersal morphological traits. Broadleaved trees had higher species richness than conifers, due to discomycetoids and pyrenomycetoids specializing in them. Re…
Effects of Natura 2000 on nontarget bird and butterfly species based on citizen science data
2020
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30…
Community structure affects trophic ontogeny in a predatory fish.
2016
While most studies have focused on the timing and nature of ontogenetic niche shifts, information is scarce about the effects of community structure on trophic ontogeny of top predators. We investigated how community structure affects ontogenetic niche shifts (i.e., relationships between body length, trophic position, and individual dietary specialization) of a predatory fish, brown trout (Salmo trutta). We used stable isotope and stomach content analyses to test how functional characteristics of lake fish community compositions (competition and prey availability) modulate niche shifts in terms of (i) piscivorous behavior, (ii) trophic position, and (iii) individual dietary specialization. …
Water temperature, not fish morph, determines parasite infections of sympatric Icelandic threespine sticklebacks (Gasterosteus aculeatus)
2013
Parasite communities of fishes are known to respond directly to the abiotic environment of the host, for example, to water quality and water temperature. Biotic factors are also important as they affect the exposure profile through heterogeneities in parasite distribution in the environment. Parasites in a particular environment may pose a strong selection on fish. For example, ecological differences in selection by parasites have been hypothesized to facilitate evolutionary differentiation of freshwater fish morphs specializing on different food types. However, as parasites may also respond directly to abiotic environment the parasite risk does not depend only on biotic features of the hos…
Species interactions, environmental gradients and body size shape population niche width
2021
1. Competition for shared resources is commonly assumed to restrict population-level niche width of coexisting species. However, the identity and abundance of coexisting species, the prevailing environmental conditions, and the individual body size may shape the effects of interspecific interactions on species’ niche width. 2. Here we study the effects of interspecific and intraspecific interactions, lake area and altitude, and fish body size on the trophic niche width and resource use of a generalist predator, the littoral-dwelling large, sparsely rakered morph of European whitefish (Coregonus lavaretus; hereafter LSR whitefish). We use stable isotope, diet and survey fishing data from 14 …
Committee Parliamentary Specialization Index. Explaining MPs’ specialisation in the Spanish Congreso de los Diputados
2019
Nowadays legislatures are largely based on committee systems. This enables a division of work and specialisation, in the context of highly complex politics and policy development. It seems clear that MP specialisation in the field of the committee they serve on is an important political asset, both for MPs and their parliamentary party group. This paper presents the Committee Parliamentary Specialization Index. This index measures the degree an MP is specialised in the jurisdiction of the committee they serve on. In the second part of the paper, the index is applied to the Spanish Congreso de los Diputados, an interesting case for testing this multi-faceted index, to find institutional, pol…
Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant
2018
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Second…
Bariery rozwoju rodzinnych gospodarstw rolnych w opinii ich właścicieli z województwa opolskiego = Barriers to the development of family farms in the…
2018
Celem opracowania jest identyfikacja zmian w zachowaniach organizacyjnych i produkcyjnych właścicieli towarowych gospodarstw rolnych służących zapewnieniu trwałości gospodarstw oraz poznanie głównych barier, których przezwyciężenie jest istotne dla budowania potencjałów rozwojowych rolnictwa i obszarów wiejskich w województwie opolskim. W badaniach uwzględniono czynniki egzogeniczne i endogeniczne, w szczególności: politykę rolną, wielowarstwowe otoczenie instytucjonalne, gotowość rolników do inwestowania, zmiany w technologii produkcji, poszukiwanie nisz specjalizacyjnych. Źródłem informacji były badania ankietowe przeprowadzone wśród właścicieli gospodarstw, produkujących głównie na rynek…
Anthropometric characteristics and vertical jump abilities by player position and performance level of junior female volleyball players
2021
Although absolute jump heights should be considered an important factor in judging the performance requirements of volleyball players, limited data is available on age-appropriate categories. The purpose of this study is to determine the differences in specific anthropometric characteristics and jumping performance variables in under−19 female volleyball players in relation to playing position and performance level. The sample of subjects consisted of 354 players who prepared for the U19 Women’s Volleyball European Championship 2020 (17.4 ± 0.8 years, 1.81 ± 0.07 m, 67.5 ± 7.1 kg). Playing positions analyzed were setters (n = 55), opposites (n = 37), middle blockers (n = 82), outside hitter…