Given a pair (semispray $S$, metric $g$) on a tangent bundle, the family of nonlinear connections $N$ such that $g$ is recurrent with respect to $(S, N)$ with a fixed recurrent factor is determined by using the Obata tensors. In particular, we obtain a characterization for a pair $(N, g)$ to be recurrent as well as for the triple $(S, stackrel{c}{N}, g)$ where $stackrel{c}{N}$ is the canonical ...

We call a module M , quasi-catenary if for each pair of quasi-prime submodules K and L of M with K L all saturated chains of quasi-prime submodules of M from K to L have a common finite length. We show that any homomorphic image of a quasi-catenary module is quasi-catenary. We prove that if M   is a module with following properties: (i) Every quasi-prime submodule of M has finite quasi-height;...

Abstract Patterns of extra pair paternity (EPP) and intraspecific brood parasitism (IBP) were studied in a Whiskered Tern Chlidonias hybrida population characterized by female desertion, high level courtship feedings (10%) low copulation (EPC; 0.6%). In this study, we used set microsatellite loci to analyse parentage 56 families from southern Poland. Depending on the method, detected that 1.4%–...

a communication net is usually represented by a linear graph g whose branches represent channels for information flow and whose vertices represent sources, sinks and switching centers. the purpose of this paper is to show that for modeling digital communication nets, conventional use of the concepts of capacity and terminal capacity is inadequate . we will present an alternative to max-flow min...

the purpose of this paper is to obtain necessary and suffcient conditionsfor existence approximate fixed point on geraghty-contraction. in this paper,denitions of approximate -pair fixed point for two maps tα , sα and theirdiameters are given in a metric space.

in this paper, we use petrov-galerkin elements such as continuous and discontinuous lagrange-type k-0 elements and hermite-type 3-1 elements to find an approximate solution for linear fredholm integro-differential equations on $[0,1]$. also we show the efficiency of this method by some numerical examples

let $mathcal {a}$ be an abelian category with enough projective objects and $mathcal {x}$ be a full subcategory of $mathcal {a}$. we define gorenstein projective objects with respect to $mathcal {x}$ and $mathcal{y}_{mathcal{x}}$, respectively, where $mathcal{y}_{mathcal{x}}$=${ yin ch(mathcal {a})| y$ is acyclic and $z_{n}yinmathcal{x}}$. we point out that under certain hypotheses, these two g...

designing and manufacturing the multiple jets simulator and experimental investigation of the multiple jets in crossflow at low velocity ratios have been studied together with design and build a low-speed wind tunnel. a specific rake is used to determine the flow field pressure and changes in static pressure measured by pressure taps in the near field of the jets. there are generally three regi...

all species in the genus lysiphlebus förster (hymenoptera: braconidae, aphidiinae) are solitary endoparasitoids of aphids, which are one of the most difficult and unknown taxonomic groups to identify. a pair of species-specific primers as a molecular marker was designed to identify the most abundant and important aphid parasitoid wasp, l. fabarum marshall, collected from guilan province (iran)....