2,636 research outputs found
Spread of \u3ci\u3eAcentria Ephemerella\u3c/i\u3e (Lepidoptera: Pyralidae) in Central North America
The aquatic moth, Acentria ephemerella, was first reported from North America in 1927. Recent records from widespread localities in central North America indicate that the range of this European introduction continues to expand. The moth is well established in the western Great Lakes region and is recorded west to the Missouri River valley in Iowa
Star formation activity of intermediate redshift cluster galaxies out to the infall regions
We present a spectroscopic analysis of two galaxy clusters out to ~4Mpc at
z~0.2. The two clusters VMF73 and VMF74 identified by Vikhlinin et al. (1998)
were observed with MOSCA at the Calar Alto 3.5m telescope. Both clusters lie in
the ROSAT PSPC field R285 and were selected from the X-ray Dark Cluster Survey
(Gilbank et al. 2004) that provides optical V- and I-band data. VMF73 and VMF74
are located at respective redshifts of z=0.25 and z=0.18 with velocity
dispersions of 671 km/s and 442 km/s, respectively. The spectroscopic
observations reach out to ~2.5 virial radii. Line strength measurements of the
emission lines H_alpha and [OII]3727 are used to assess the star formation
activity of cluster galaxies which show radial and density dependences. The
mean and median of both line strength distributions as well as the fraction of
star forming galaxies increase with increasing clustercentric distance and
decreasing local galaxy density. Except for two galaxies with strong H_alpha
and [OII] emission, all of the cluster galaxies are normal star forming or
passive galaxies. Our results are consistent with other studies that show the
truncation in star formation occurs far from the cluster centre.Comment: 15 pages, 12 figures. A&A in pres
Metabolite-mediated catalyst conversion of PFK and PFP
Metabolites known to occur in the cytosol of photosynthetic leaf cells were found to mediate the reversible conversion of pyrophosphate—D-fructose-6-phosphate 1-phosphotransferase (PFP) to phosphofructokinase (PFK) in partially purified preparations from spinach leaves. Preincubation of PFP with fructose 2,6-bisphosphate, ATP or fructose 6-phosphate converted PFP to PFK. The reverse reaction (PFK → PFP) was promoted by UDP-glucose plus pyrophosphate. These conversions in catalytic capability were accompanied by changes in molecular mass and charge. The results are in accord with the view that the alterations in PFP and PFK activity, provisionally called ‘metabolite-mediated catalyst conversion’, represent a regulatory mechanism to direct left cytosolic carbon flux in either the biosynthetic or degradatory direction
Metallic magnetism at finite temperatures studied by relativistic disordered moment description: Theory and applications
We develop a self-consistent relativistic disordered local moment (RDLM)
scheme aimed at describing finite temperature magnetism of itinerant metals
from first principles. Our implementation in terms of the
Korringa--Kohn--Rostoker multiple scattering theory and the coherent potential
approximation allows to relate the orientational distribution of the spins to
the electronic structure, thus a self-consistent treatment of the distribution
is possible. We present applications for bulk bcc Fe, L1-FePt and FeRh
ordered in the CsCl structure. The calculations for Fe show significant
variation of the local moments with temperature, whereas according to the mean
field treatment of the spin fluctuations the Curie temperature is
overestimated. The magnetic anisotropy of FePt alloys is found to depend
strongly on intermixing between nominally Fe and Pt layers, and it shows a
power-law behavior as a function of magnetization for a broad range of chemical
disorder. In case of FeRh we construct a lattice constant vs. temperature phase
diagram and determine the phaseline of metamagnetic transitions based on
self-consistent RDLM free energy curves.Comment: 11 pages, 8 figure
Financial Planning for Real Estate Production Decisions
Recently, the production and service components of the real estate business have evolved from collections of mom and pop operations to full-fledged industries comprised of highly competitive, small and medium-sized firms. This evolution to larger-scale business operations has important implications for the type of financial analysis to be conducted by real estate firms in the future. Specifically, the traditional project-specific financial analysis of real estate investment opportunities will be subsumed by strategic financial planning for real estate decisions at the firm level. Even with a radical change in emphasis and interpretation, the discounted cash flow tradition, firmly established in project-specific analysis, is likely to remain since it underlies most strategic financial planning models. This article details how such a model can be used by firms to make real estate production decisions
The galaxy populations from the centers to the infall regions in z~0.25 clusters
We conducted a panoramic spectroscopic campaign with MOSCA at the Calar Alto
observatory. We acquired spectra of more than 500 objects. Approximately 150 of
these spectra were of galaxies that are members of six different clusters,
which differ in intrinsic X-ray luminosity. The wavelength range allows us to
quantify the star formation activity by using the OII and the Halpha lines.
This activity is examined in terms of the large-scale environment expressed by
the clustercentric distance of the galaxies as well as on local scales given by
the spatial galaxy densities. A global suppression of star-formation is
detected in the outskirts of clusters, at about 3Rvir. Galaxies with ongoing
star-formation have similar activity, regardless of the environment. Therefore,
the decline of the star-formation activity inside the investigated clusters is
driven mainly by the significant change in the fraction of active versus
passive populations. This suggests that the suppression of the star-formation
activity occurs on short timescales. We detect a significant population of red
star-forming galaxies whose colors are consistent with the red-sequence of
passive galaxies. They appear to be in an intermediate evolutionary stage
between active and passive types. Since a suppression of star-formation
activity is measured at large clustercentric distances and low projected
densities, purely cluster-specific phenomena cannot fully explain the observed
trends. Therefore, as suggested by other studies, group preprocessing may play
an important role in transforming galaxies before they enter into the cluster
environment. Since models predict that a significant fraction of galaxies
observed in the outskirts may have already transversed through the cluster
center, the effects of ram-pressure stripping cannot be neglected. (ABRIDGED)Comment: Revised version. Astronomy and Astrophysics in press. Important typo
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