Ambystoma opacum

Number of Pages: 2Integrative BiologyGeological Science

Phase detector assembly Patent

Detector assembly for discriminating first signal with respect to presence or absence of second signal at time of occurrence of first signa

Systematics of the North American menhadens: molecular evolutionary reconstructions in the genus Brevoortia (Clupeiformes: Clupeidae)

Evolutionary associations among the four North American species of menhadens (Brevoortia spp.) have not been thoroughly investigated. In the present study, classifications separating the four species into small-scaled and large-scaled groups were evaluated by using DNA data, and genetic associations within these groups were explored. Specifically, data from the nuclear genome (microsatellites) and the mitochondrial genome (mtDNA sequences) were used to elicit patterns of recent and historical evolutionary associations. Nuclear DNA data indicated limited contemporary gene flow among the species, and also indicated higher relatedness within the small-scaled and large-scaled menhadens than between these groups. Mitochondrial DNA sequences of the large-scaled menhadens indicated the presence of two ancestral lineages, one of which contained members of both species. This result may indicate genetic diver-gence (reproductive isolation) followed by secondary contact (hybridization) between these species. In contrast, a single ancestral lineage indicated incomplete genetic divergence between the small-scaled menhaden. These results are discussed in the context of the biology and demographics of each species

Dicamptodon and D. ensatus

Number of Pages: 2Integrative BiologyGeological Science

Effects of equivalence ratio and dwell time on exhaust emissions from an experimental premixing prevaporizing burner

A flame-tube study was performed to determine the effects of equivalence ratio and residence time on exhaust emissions with premixed, prevaporized propane fuel. Nitrogen oxides emissions as low as .3 g NO2/kg fuel were measured with greater than 99% combustion efficiency at 800 K inlet temperature and an equivalence ratio of .4. For a constant combustion efficiency, lower nitrogen oxides emissions were obtained by burning very lean with relatively long residence times than by using somewhat higher equivalence ratios with shorter times

The ground state and the long-time evolution in the CMC Einstein flow

Let (g,K)(k) be a CMC (vacuum) Einstein flow over a compact three-manifold M with non-positive Yamabe invariant (Y(M)). As noted by Fischer and Moncrief, the reduced volume V(k)=(-k/3)^{3}Vol_{g(k)}(M) is monotonically decreasing in the expanding direction and bounded below by V_{\inf}=(-1/6)Y(M))^{3/2}. Inspired by this fact we define the ground state of the manifold M as "the limit" of any sequence of CMC states {(g_{i},K_{i})} satisfying: i. k_{i}=-3, ii. V_{i} --> V_{inf}, iii. Q_{0}((g_{i},K_{i}))< L where Q_{0} is the Bel-Robinson energy and L is any arbitrary positive constant. We prove that (as a geometric state) the ground state is equivalent to the Thurston geometrization of M. Ground states classify naturally into three types. We provide examples for each class, including a new ground state (the Double Cusp) that we analyze in detail. Finally consider a long time and cosmologically normalized flow (\g,\K)(s)=((-k/3)^{2}g,(-k/3))K) where s=-ln(-k) is in [a,\infty). We prove that if E_{1}=E_{1}((\g,\K))< L (where E_{1}=Q_{0}+Q_{1}, is the sum of the zero and first order Bel-Robinson energies) the flow (\g,\K)(s) persistently geometrizes the three-manifold M and the geometrization is the ground state if V --> V_{inf}.Comment: 40 pages. This article is an improved version of the second part of the First Version of arXiv:0705.307

Ambystoma ordinarium

Number of Pages: 2Integrative BiologyGeological Science