—The southwestern edge of the natural range of smallmouth bass Micropterus dolomieu contains streams that become disconnected pools during summer primarily owing to hydrogeologic conditions, including high evapotranspiration rates. These conditions may complicate fisheries management by affecting fish behavior or mortality rates. The objectives of this study were to characterize summer habitat ...

We report the discovery of a quasi-periodic oscillation (QPO) at 61.0±1.7 Hz with the Rossi X-Ray Timing Explorer in the low-mass X-ray binary and persistently bright atoll source GX 13+1 (4U 1811–17). The QPO had an rms amplitude of 1.7±0.2% (2–13.0 keV) and a FWHM of 15.9±4.2 Hz. Its frequency increased with count rate and its amplitude increased with photon energy. In addition a peaked noise...

laan in (ph.d thesis, tartu. 1999) introduced the principal weak form of condition $(p)$ as condition $(pwp)$ and gave some characterization of monoids by this condition of their acts. in this paper first we introduce condition (g-pwp), a generalization of condition $(pwp)$ of acts over monoids and then will give a characterization of monoids when all right acts satisfy this condition. we also ...

Barbara Janowitz is dire c t o r, Health Services Researc h G roup, Family Health International (FHI), Research Tr iangle Park, NC, USA. Jane Chege is re s e a rch associate, FRONTIERS Project, Population Council, Nairobi, Kenya. A n d rew Thompson, formerly with FHI, is now administ r a t o r, Health Policy Unit, Organization for Economic Cooperation and Development, Paris. Naomi Rutenberg is ...

A ring $R$ with identity is called ``clean'' if $~$for every element $ain R$, there exist an idempotent $e$ and a unit $u$ in $R$ such that $a=u+e$. Let $C(R)$ denote the center of a ring $R$ and $g(x)$ be a polynomial in $C(R)[x]$. An element $rin R$ is called ``g(x)-clean'' if $r=u+s$ where $g(s)=0$ and $u$ is a unit of $R$ and, $R$ is $g(x)$-clean if every element is $g(x)$-clean. In this pa...