Search results for "Systematics"
showing 10 items of 6702 documents
Effects of precipitation seasonality, irrigation, vegetation cycle and soil type on enhanced weathering – modeling of cropland case studies across fo…
2022
Enhanced weathering (EW) is a promising strategy for carbon sequestration, but several open questions remain regarding the actual rates of dissolution in conditions of natural hydroclimatic variability in comparison to laboratory experiments. In this context, models play a pivotal role, as they allow exploring and predicting EW dynamics under different environmental conditions. Here a comprehensive hydro-biogeochemical model has been applied to four cropland case studies (i.e., Sicily and the Padan plain in Italy and California and Iowa in the USA) characterized by different rainfall seasonality, vegetation (i.e., wheat for Sicily and California and corn for the Padan plain and Iowa), and s…
Variability in δ13C values between individual Daphnia ephippia: Implications for palaeo-studies
2018
The stable carbon isotope ratio (δ13C value) of Daphnia spp. resting egg shells (ephippia) provides information on past changes in Daphnia diet. Measurements are typically performed on samples of ≥20 ephippia, which obscures the range of values associated with individual ephippia. Using a recently developed laser ablation-based technique, we perform multiple δ13C analyses on individual ephippia, which show a high degree of reproducibility (standard deviations 0.1–0.5‰). We further measured δ13C values of 13 ephippia from surface sediments of three Swiss lakes. In the well-oxygenated lake with low methane concentrations, δ13C values are close to values typical for algae (−31.4‰) and the rang…
Interspecific attraction between ground-nesting songbirds and ants: the role of nest-site selection
2021
Abstract Background Interspecific interactions within ecological networks can influence animal fitness and behaviour, including nest-site selection of birds and ants. Previous studies revealed that nesting birds and ants may benefit from cohabitation, with interspecific attraction through their nest-site choice, but mutual interactions have not yet been tested. We explored a previously undescribed ecological link between ground-nesting birds and ants raising their own broods (larvae and pupae) within the birds’ nests in a temperate primeval forest of lowland Europe. We tested whether the occurrence of ant broods within bird nests resulted from a mutual or one-sided interspecific attraction …
Typification and synonymization inPrimulasect.Auricula(Primulaceae)
2005
Supplementing a recent systematic study of Primula sect. Auricula, we here lectotypify or neotypify 27 names applicable to taxa in this section and the name of one related genus. These are P. auricula var. widmerae Pax, P. balbisii Lehm., P. ciliata Moretti, P. cottia Widmer, P. crenata Lam., P. oenensis Thomas ex Gremli, P. glaucescens Moretti, P. glutinosa Wulfen, P. integrifolia L., P. latifolia var. cynoglossifolia Widmer, P. laevigata Duby ex Rchb., P. longobarda Parta, P. lutea Vill., P. marginata Curtis, P. microcalyx Lehm., P. minima L., P. parlatorii Porta ex Caruel, P. villosa Wulfen, P. villosa var. daonensis Leyb., P. viscosa Vill., P. [unranked] Brevihracteae Widmer, P. [unrank…
Nomenclature ofSoldanellaL. (Primulaceae)
2004
Following a revision of Soldanella, we here synonymize 109 non-hybrid names of this genus. We also lectotypify or neotypify 17 names of Soldanella. These are S. alpina L., S. alpina F. W. Schmidt, S. alpina L. var. carestiae Cristofolini et Pignatti, S. alpina L. f. major Cristofolini et Pignatti, S. austriaca Vierh., S. carpatica Vierh., S. marmarossiensis Kldst., S. minima Hoppe, S. minima Hoppe subsp. samnitica Cristofolini et Pignatti, S. minima Hoppe f. latifolia Cristofolini et Pignatti, S. montana Mikan, S. montana Willd., S. montana Willd. subsp. faceta Kress, S. occidentalis Vierh., S. pusilla Baumg., S. pusilla Baumg. f. calcicola Vierh., and S. pusilla Baumg. var. chrysosplenifol…
Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes
2007
Abstract Background The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey. Results We report cloning of two MC receptors from river lamprey. The lamprey receptors, designated MCa and MCb, showed orthology to the MC1 and MC4 receptor subtypes, respectively. The molecular clock analysis suggested that lamprey MC receptor genes were not duplicated recently and diverged from each other more than 400 MYR ago. Expression and pharmacological characterization showed that the lamprey MCa receptor …
Comparison of Two Chemicals for Removing an Entocytherid (Ostracoda: Crustacea) Species from Its Host Crayfish (Cambaridae: Crustacea)
2011
Entocytherids are epifauna on larger crustaceans. We assessed the effectiveness of chlorobutanol and carbonated water for removing entocytherid, Ankylocythere sinuosa, from crayfish, Procambarus clarkii. This was done using different exposure times and by assessing entocytherid and crayfish survival, together with the number of entocytherids removed. According to our results, chlorobutanol submersion of crayfishes in shorter time periods is more effective for removing entocytherids without killing the crayfish host. However, carbonated water submersion is better to extract larger amounts of living entocytherids. Finally, both chemicals are appropriate tools to establish standardised protoco…
Phylogenetic relationship among genera of Polymorphidae (Acanthocephala), inferred from nuclear and mitochondrial gene sequences.
2013
Abstract Acanthocephalans of the family Polymorphidae Meyer, 1931 are obligate endoparasites with complex life cycles. These worms use vertebrates (marine mammals, fish-eating birds and waterfowl) as definitive hosts and invertebrates (amphipods, decapods and euphausiids) as intermediate hosts to complete their life cycle. Polymorphidae has a wordwide distribution, containing 12 genera, with approximately 127 species. The family is diagnosed by having a spinose trunk, bulbose proboscis, double-walled proboscis receptacle, and usually four to eight tubular cement glands. To conduct a phylogenetic analysis, in the current study sequences of the small (18S) and large-subunit (28S) ribosomal RN…
Studies on the fat body of oncopeltus fasciatus invaded by pseudomonas aeruginosa1
1977
A fatal disease in laboratory cultures of Oncopeltus fasciatus is caused by Pseudomonas aeruginosa , which invades the fat body and destroys it. The cellular breakdown was studied by electron microscopy. Infected fat body tissue shrinks, disintegrates, and dissolves. The nuclei, apparently, remain intact until immediately before cell death. Bacteria, which are found singularly in cytoplasm, form an expanding electron-lucent halo. Within this halo, free ribosomes and ribosomes of rough endoplasmic reticulum (ER) disappear. The changes are presumably caused by proteolytic activity of the parasite, which results in the destruction of the fat body and death of the host. Lipid droplets dissolve,…
<p class="HeadingRunIn"><strong>Six new <em>Dinotrema</em> species (Hymenoptera, Braconidae) from Spain, with prescutellar pi…
2013
Descriptions of six new species of the genus Dinotrema from Spain with smooth or only medially sculptured propodeum are provided. The new species described are: D. achterbergi sp. nov., D. broadi sp. nov., D. enanum sp. nov., D. fischerianum sp. nov., D. munki sp. nov. and D. pappi sp. nov.