Search results for "Copula"

Xanthones and sesquiterpene derivatives from a marine-derived fungus Scopulariopsis sp.

2016

Abstract Two new xanthone derivatives, 12-dimethoxypinselin ( 1 ) and 12- O -acetyl-AGI-B4 ( 2 ), as well as two new phenolic bisabolane-type sesquiterpenes, 11,12-dihydroxysydonic acid ( 15 ) and 1-hydroxyboivinianic acid ( 16 ), together with one new alkaloid, scopulamide ( 21 ) and one new α-pyrone derivative, scopupyrone ( 26 ), in addition to twenty-three known compounds ( 3 – 14 , 17 – 20 , 22 – 25 , 27 – 29 ) were isolated from solid rice cultures of the marine-derived fungus Scopulariopsis sp. obtained from the Red Sea hard coral Stylophora sp. All compounds were unambiguously identified through extensive NMR spectroscopic analyses, and by comparison with the literature. Marfey's re…

Body size and mating strategies in the simultaneous hermaphrodite Oxynoe olivacea (Mollusca, Opisthobranchia, Sacoglossa).

2004

Summary 1To better understand the role and importance of body size in hermaphroditic mating system theory, the mating behaviour of the shelled sacoglossan Oxynoe olivacea was studied. This simultaneous hermaphrodite exhibits bilateral and unilateral sperm transfer and thus it is particularly suitable for studies on hermaphrodite sexual conflict. 2In this study three hypotheses on body size were tested: that O. olivacea partner size has an effect on (i) mating mode choice, (ii) duration of mating modes, and (iii) choice of sexual role. Furthermore, we tested Charnov's hypothesis that in O. olivacea, like many simultaneous hermaphrodites, a sexual conflict exists and the male role is preferre…

La coordinación copulativa con y: condiciones de coordinabilidad

1987

En este trabajo pasamos revista a los diferentes requisitos de coordinabilidad aducidos en la bibliografía que se ha ocupado del tema. Hecho esto, y después de haber presentado el modelo explicativo de la coordinación copulativa que defendemos, tratamos de mostrar que ese modelo es capaz de explicar las condiciones gramaticales a que está sujeta la coordinación copulativa en español.

Using copulas in finding a lower bound for functions of dependent risks

2006

Biocontrol of drosophila suzukii by two fatty acids

2020

International audience; Olfaction is a crucial sense for insects to detect food, seek partners or escape dangers. Volatile molecules are mainly perceived through insects' antenna. Odors bind to specific olfactory receptors located in sensilla. Olfactory sensory neurons then synapse on corresponding specific glomeruli of the antennal lobe, the primary olfaction center. This olfactory information is processed in higher centers to trigger a behavioral response. Understanding how odors can influence insect behavior is fundamental in order to protect cultures from pests. In this work, 2 volatile fatty acids are shown to modify significantly Drosophila suzukii courtship and copulation at increasi…

Uncertain Characterization of Flood Hazard Using Bivariate Analysis Based on Copulas

2015

This study presents a methodology to derive probabilistic flood hazard map in flood prone areas taking into account uncertainties in the definition of design-hydrographs. Particularly, we present an innovative approach to obtain probabilistic inundation and flood hazard maps where hydrological input (synthetic flood design event) to a 2D hydraulic model has been defined by generating flood peak discharges and volumes from a bivariate statistical analysis, through the use of copulas. This study also aims to quantify the contribution of boundary conditions uncertainty in order to explore the impact of this uncertainty on probabilistic flood hazard mapping. The uncertainty of extreme flood eve…

Estimation of synthetic flood design hydrographs using a distributed rainfall–runoff model coupled with a copula-based single storm rainfall generator

2014

Abstract. In this paper a procedure to derive synthetic flood design hydrographs (SFDH) using a bivariate representation of rainfall forcing (rainfall duration and intensity) via copulas, which describes and models the correlation between two variables independently of the marginal laws involved, coupled with a distributed rainfall–runoff model, is presented. Rainfall–runoff modelling (R–R modelling) for estimating the hydrological response at the outlet of a catchment was performed by using a conceptual fully distributed procedure based on the Soil Conservation Service – Curve Number method as an excess rainfall model and on a distributed unit hydrograph with climatic dependencies for the …

Data from: Postmating-prezygotic isolation between two allopatric populations of Drosophila montana: fertilisation success differs under sperm compet…

2017

Postmating but prezygotic (PMPZ) interactions are increasingly recognized as a potentially important early-stage barrier in the evolution of reproductive isolation. A recent study described a potential example between populations of the same species: single matings between Drosophila montana populations resulted in differential fertilisation success because of the inability of sperm from one population (Vancouver) to penetrate the eggs of the other population (Colorado). As the natural mating system of D. montana is polyandrous (females remate rapidly), we set up double matings of all possible crosses between the same populations to test whether competitive effects between ejaculates influe…

Kin selection in interactions between gametes: Gamete competition, gamete limitation, and sex allocation

2023

Kin selection on one hand, and gamete interactions in post-ejaculatory sexual selection on the other are two major research themes that have risen to prominence over the past half century and have simultaneously developed into central fields of research in evolutionary biology. There is a natural connection between the two: when gametes interact with each other, very commonly many of them originate from the same parent and are thus siblings. For example, sperm competition will almost always involve competition between sibling gametes even if the interacting parents are not related to each other. If parents are related to each other, the relatedness between gametes increases further. Here we…