Search results for " Systematics."
showing 10 items of 4820 documents
Parental investment asymmetries of a globally endangered scavenger: unravelling the role of gender, weather conditions and stage of the nesting cycle
2019
Capsule: In Egyptian Vultures Neophron percnopterus, both sexes invested similar parental effort throughout the breeding period. However, there was variation in the degree of intensity of parental ...
Composition and allelopathic effect of essential oils of two thistles: Cirsium creticum (Lam.) D.�Urv. ssp. triumfetti (Lacaita) Werner and Carduus n…
2007
Abstract Cirsium and Carduus are two of the main genera of true thistles. Different species in these genera share a quantity of secondary metabolites and have interesting ecological properties. The essential oils of two species, Cirsium creticum and Carduus nutans, were analysed, showing the presence as main compounds of 4-ethyl guaiacol (15%), hexadecanoic acid (10.6%), (E)-β-damascenone (7.8%), dihydroactinidiolide (6.0%) and 4-vinyl guaiacol (4.5%) for C. creticum and hexadecanoic acid (18.6%), hexahydrofarnesylacetone (7.8%), heptacosane (5.9%), 4-vinyl guaiacol (5.8%), pentacosane (3.8%) and eugenol (3.6%) for C. nutans. The oils were evaluated at different doses for their effect on ge…
Female choice in the kestrel under different availability of mating options
1992
Abstract Mate choice in relation to its fitness consequences on females was studied in kestrels, Falco tinnunculus , in western Finland. The breeding season is short with rapidly declining prospects of successful breeding, suggesting that females should make their mating decision quickly. On average, males arrived a few days before females, but late males arrived much later than early females. Pairs were usually formed within 2 days of male arrival, and only early males were available to early females. Options for female choice differed considerably in years of different kestrel density. In a good vole year, 1988, females had many males to choose from, but in poor vole years, 1989 and 1990,…
MORPHOLOGICAL AND ANATOMICAL STRUCTURE OF GALLS IN GENISTA FLORIDA L. SUBSP. POLYGALIPHYLLA (BROT.) COUTHINO (LEGUMINOSAE)
1999
This paper describes the morphology and anatomy of a structure which appears in the floral racemes of Genista florida L. subsp. polygaliphylla (Brot.) Couthino. In this subspecies the floral racemes have a small number of flowers. This structure develops quite frequently in this taxon, which is found in the northwest of the Iberian Peninsula, but never in Genista florida subsp. florida. Its morphology is simple: bottle-shaped, wide at the base and elongated to a narrow peak at the upper extreme. Anatomical examination shows that these structures have a close similarity to flowers. Since they develop by the oviposition of one insect of the Cecidomyiidae family in the floral buds, they can be…
Determining Behavioural Syndromes in Voles - The Effects of Social Environment
2010
Animal personality and behavioural syndromes have experienced rapid increase in interest in the last few years because of their possible role in the evolution of life histories. However, there is still a scarcity of studies concerning the mechanisms maintaining variation in behaviour as well as addressing their relationships to each other. In this paper, we tested the main assumptions of personality, focusing on the individual variability and repeatability of behaviour, and the identification of behavioural syndromes using the common vole (Microtus arvalis) as the species being studied. We also studied the effects of family group characters (group size, sex ratio and affinity to family) on …
Modulation of immune responses ofRhynchophorus ferrugineus(Insecta: Coleoptera) induced by the entomopathogenic nematodeSteinernema carpocapsae(Nemat…
2014
Aim of this study was to investigate relationships between the red palm weevil (RPW) Rhynchophorus ferrugineus (Olivier) and the entomopathogenic nematode Steinernema carpocapsae (EPN); particularly, the work was focused on the immune response of the insect host in naive larvae and after infection with the EPN. Two main immunological processes have been addressed: the activity and modulation of host prophenoloxidase-phenoloxidase (proPO) system, involved in melanization of not-self and hemocytes recognition processes responsible for not-self encapsulation. Moreover, immune depressive and immune evasive strategies of the parasite have been investigated. Our results suggest that RPW possess a…
Action de la chlorhexidine sur l'expression de la virulence de
1999
Abstract Candida albicans is an opportunistic yeast. Its pathogenicity is linked to the susceptibility of the host surface as well as to particular factors of the strain: adhesion, filamentous growth and secretion of proteolytic enzymes. Chlorhexidine digluconate is an antiseptic with fungicidal properties. The action of the antiseptic on the growth of the yeast shows a minimal inhibitory concentration (MIC) at 50 μg·mL−1 and a minimal fungicidal concentration (MFC) at 100 μg·mL−1. The consequences of antiseptic treatment are studied using two indicators of pathogenicity: filamentation and the secretion of acid proteinase. Concerning the morphological indicator, a complete inhibition of fil…
Stable isotope (δ18O and δ13C) sclerochronology of Callovian (Middle Jurassic) bivalves (Gryphaea (Bilobissa) dilobotes) and belemnites (Cylindroteut…
2014
Abstract Incremental δ 18 O and δ 13 C signals were obtained from three well-preserved specimens of Cylindroteuthis puzosiana and from three well-preserved specimens of Gryphaea ( Bilobissa ) dilobotes from the Peterborough Member of the Oxford Clay Formation (Cambridgeshire, England). Through-ontogeny (sclerochronological) δ 18 O data from G. ( B. ) dilobotes appear to faithfully record seasonal temperature variations in benthic Callovian waters of the study area, which range from c . 14 °C to c . 17 °C (arithmetic mean temperature c . 15 °C). Water depth is estimated to have been in the region of c . 50 m, based upon comparisons between these data, previously published non-incremental sea…
Tarbellastraea (Scleractinia): A new stable isotope archive for Late Miocene paleoenvironments in the Mediterranean
2008
Abstract Geochemical proxy records of sea surface temperature (SST) or sea surface salinity (SSS) variability on intra- and interannual time-scales in corals from geological periods older than Pleistocene are extremely rare due to pervasive diagenetic alteration of coralline aragonite. Very recently, however, stable isotope data (δ18O, δ13C) from specimens of Porites of Late Miocene age (10 Ma) have been shown to preserve original environmental signatures. In this paper we describe new finds of the zooxanthellate corals Porites and Tarbellastraea in exceptional aragonite preservation from the island of Crete in sediments of Tortonian (∼ 9 Ma) and Early Messinian (∼ 7 Ma) age. Systematic, co…
Sexually selected traits evolve positive allometry when some matings occur irrespective of the trait
2014
Positive allometry of secondary sexual traits (whereby larger individuals have disproportionally larger traits than smaller individuals) has been called one of the most pervasive and poorly understood regularities in the study of animal form and function. Its widespread occurrence is in contrast with theoretical predictions that it should evolve only under rather special circumstances. Using a combination of mathematical modeling and simulations, here we show that positive allometry is predicted to evolve under much broader conditions than previously recognized. This result hinges on the assumption that mating success is not necessarily zero for males with the lowest trait values: for examp…