let $r$ be a commutative ring with identity and $mathbb{a}(r)$ be the set   of ideals of $r$ with non-zero annihilators. in this paper, we first introduce and investigate the principal ideal subgraph of the annihilating-ideal graph of $r$, denoted by $mathbb{ag}_p(r)$. it is a (undirected) graph with vertices $mathbb{a}_p(r)=mathbb{a}(r)cap mathbb{p}(r)setminus {(0)}$, where   $mathbb{p}(r)$ is...

Fish growth is commonly used as a proxy for fitness but this is only valid if individual growth variation can be interpreted in relation to conspecifics' performance. Unfortunately, assessing individual variation in growth rates is problematic under natural conditions because subjects typically need to be marked, repeated measurements of body size are difficult to obtain in the field, and recap...

this is a survey of some recent applications of abstract algebra, and in particular group rings, to the `communications' areas.

Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC i...

Abstract This chapter aims at summarizing strengths and caveats on the suitability of stable carbon oxygen isotopes in tree rings as recorders for fingerprints environmental influences. First, constraints limiting growth shaping species distribution worldwide are discussed. Second, examples presented conditions under which tree-ring record signals particularly well, but also cases where physiol...

In this paper, we introduce the new notion of n-f-clean rings as a generalization of f-clean rings. Next, we investigate some properties of such rings. We prove that $M_n(R)$ is n-f-clean for any n-f-clean ring R. We also, get a condition under which the denitions of n-cleanness and n-f-cleanness are equivalent.

Culture of dispersed smooth muscle cells is known to cause rapid modulation from the contractile to the synthetic cellular phenotype. However, organ culture of smooth muscle tissue, with maintained extracellular matrix and cell-cell contacts, may facilitate maintenance of the contractile phenotype. To test the influence of culture conditions, structural, functional, and biochemical properties o...

atropine has been used to block cholinergic neurotransmission in basic research. large doses of atropine cause vasodilation of the blood vessels in the skin. this effect is apparently unconnected with the antimuscarinic activity of atropine and seems to be due to a direct action on the blood vessels. it has been suggested that atropine blocks muscarinic receptors at low doses and it induces the...

In temperate climates, tree growth dormancy usually ensures the annual nature of tree rings, but in tropical environments, determination of annual periodicity can be more complex. The purposes of the work are as follows: (1) to generate a reliable tree-ring width chronology for Prioria copaifera Griseb. (Leguminoceae), a tropical tree species dwelling in the Atrato River floodplains, Colombia; ...