Historical review of C-5A lift distribution control systems

Analytical and experimental development work on various load alleviation systems for the C-5A is reviewed to trace the development of the technical and hardware concepts to the present time. Variations in system objectives, means of implementation and effects on loads and airplane performance, stability and control are discussed

Seeing Galaxies Through Thick & Thin. III. HST Imaging of the Dust in Backlit Spiral Galaxies

We present analysis of WFPC2 imaging of two spiral galaxies partially backlit by E/S0 systems in the pairs AM1316-241 and AM0500-620, and the spiral foreground system in NGC 1275. Images in B and I are used to determine the reddening curve of in these systems. The spiral component of AM1316-241 shows dust strongly concentrated in discrete arms, with a reddening law very close to the Milky Way mean. The dust distribution is scale-free between about 100 pc and the arm scale. The spiral in AM0500-620 shows dust concentrated in arms and interarm spurs, with measurable interarm extinction as well. Although its dust properties are less well-determined, we find evidence for a steeper extinction law here. The shape of the reddening law suggests that, at least in AM1316-241, we have resolved most of the dust structure. In AM0500-620, the slope of the fractal perimeter-scale relation steepens systematically from low to high extinction. In AM1316-241, we cannot determine a unique fractal dimension from the defining area-perimeter relation, so the projected dust distribution is best defined as fractal-like. In neither galaxy do we see regions even on single-pixel scales in spiral arms with AB > 2.5. The measurements in NGC 1275 are compromised by our lack of independent knowledge of the foreground system's light distribution, but masked sampling of the absorption suggests an effective reddening curve much flatter than the Milky Way mean (perhaps indicating that the foreground system has been affected by immersion in the hot intracluster gas).Comment: Astronomical Journal, in press. 13 figures. Full-size PostScript figures available at http://www.astr.ua.edu/preprints/kee

A MARKOV CHAIN ANALYSIS OF PORK FARM SIZE DISTRIBUTIONS IN THE SOUTH: REPLY

Livestock Production/Industries,

Scanning Electron Microscopy of Chromosomes and Chromosome Fragments in Transgenic Rainbow Trout

Chromosomes and chromosome fragments from embryonic offspring of a transgenic rainbow trout were examined using scanning electron microscopy (SEM). SEM is an extremely useful technique for studying the structure of chromosome fragments since little morphological detail is revealed by conventional staining methodologies and light microscopy. The chromosome preparations were processed for SEM by combining an osmium-thiocarbohydrazide-osmium (OTO) technique with 2-4 nm of gold deposition. This technique revealed the organization of individual chromatin fibers in chromosome fragments and intact chromosomes. Both a linear chromosome fragment with a width similar to that of an intact chromatid (approximately 0.60 micrometers) and a spherical chromosome fragment with a diameter slightly greater than the width of an intact chromatid (0.66 micrometers) were observed in metaphase chromosome preparations. A connective fiber (200-300 nm in diameter) between a chromosome fragment and a host chromosome was observed. Interconnecting fibers (approximately 30 nm in diameter) between chromosomes, between chromosomes and fragments, and between sister chromatids were observed in every cell examined. We conclude that SEM permits a detailed analysis of chromosome fragment structure and the nature of chromosome-fragment associations that cannot be obtained using conventional light microscopy techniques

The Globular Cluster Systems around NGC 3311 and NGC 3309

We present extensive new photometry in (g',i') of the large globular cluster (GC) system around NGC 3311, the central cD galaxy in the Hydra cluster. Our GMOS data cover a 5.5' field of view and reach a limiting magnitude i' = 26, about 0.5 magnitude fainter than the turnover point of the GC luminosity function. We find that NGC 3311 has a huge population of ~16, 000 GCs, closely similar to the prototypical high specific frequency Virgo giant M87. The color-magnitude distribution shows that the metal-poor blue GC sequence and the metal-richer red sequence are both present, with nearly equal numbers of clusters. Bimodal fits to the color distributions confirm that the blue sequence shows the same trend of progressively increasing metallicity with GC mass that has previously been found in many other large galaxies; the correlation we find corresponds to a scaling of GC metallicity with mass of Z ~ M^0.6 . By contrast, the red sequence shows no change of mean metallicity with mass, but it shows an upward extension to much higher than normal luminosity into the UCD-like range, strengthening the potential connections between massive GCs and UCDs. The GC luminosity function, which we measure down to the turnover point at M_I = -8.4, also has a normal form like those in other giant ellipticals. Within the Hydra field, another giant elliptical NGC 3309 is sitting just 100" from the cD NGC 3311. We use our data to solve simultaneously for the spatial structure and total GC populations of both galaxies at once. Their specific frequencies are S_N (NGC 3311) = 12.5 +/- 1.5 and S_N (NGC 3309) = 0.6 +/-0.4. NGC 3311 is completely dominant and entirely comparable with other cD-type systems such as M87 in Virgo.Comment: 15 pages, 15 figures. Accepted to the Astrophysical Journal. Version with higher resolution figures is available at http://www.thewehners.net/astro/papers/wehner_n3311_highres.pd

Does funding of pensions stimulate economic growth?

Copyright © 2008 Cambridge University Press.Debate over superiority of pension funding over pay-as-you-go links notably to the question whether funding improves economic performance sufficiently to generate additional resources to meet the needs of an ageing population. To address this issue, we design a modified Cobb–Douglas production function with pension assets as a shift factor, and investigate the direct link between pension assets and economic growth employing a dataset covering up to 38 countries, using a variety of appropriate econometric methods. We find positive results for both OECD countries and Emerging Market Economies (EMEs), with consistent evidence for a larger effect for EMEs than OECD countries

Dust Attenuation in Late-Type Galaxies. I. Effects on Bulge and Disk Components

We present results of new Monte Carlo calculations made with the DIRTY code of radiative transfer of stellar and scattered radiation for a dusty giant late-type galaxy like the Milky Way, which illustrate the effect of the attenuation of stellar light by internal dust on the integrated photometry of the individual bulge and disk components. Here we focus on the behavior of the attenuation function, the color excess, and the fraction of light scattered or directly transmitted towards the outside observer as a function of the total amount of dust and the inclination of the galaxy, and the structure of the dusty interstellar medium (ISM) of the disk. We confirm that dust attenuation produces qualitatively and quantitatively different effects on the integrated photometry of bulge and disk, whatever the wavelength. In addition, we find that the structure of the dusty ISM affects more sensitively the observed magnitudes than the observed colors of both bulge and disk. Finally, we show that the contribution of the scattered radiation to the total monochromatic light received by the outside observer is significant, particularly at UV wavelengths, even for a two-phase, clumpy, dusty ISM. Thus understanding dust scattering properties is fundamental for the interpretation of extragalactic observations in the rest-frame UV.Comment: 62 pages, 28 eps-figures, 1 table, accepted for publication in ApJ Main Journa

Non-intersecting leaf insertion algorithm for tree structure models

We present an algorithm and an implementation to insert broadleaves or needleleaves to a quantitative structure model according to an arbitrary distribution, and a data structure to store the required information efficiently. A structure model contains the geometry and branching structure of a tree. The purpose of the work is to offer a tool for making more realistic simulations with tree models with leaves, particularly for tree models developed from terrestrial laser scan (TLS) measurements. We demonstrate leaf insertion using cylinder-based structure models, but the associated software implementation is written in a way that enables the easy use of other types of structure models. Distributions controlling leaf location, size and angles as well as the shape of individual leaves are user-definable, allowing any type of distribution. The leaf generation process consist of two stages, the first of which generates individual leaf geometry following the input distributions, while in the other stage intersections are prevented by doing transformations when required. Initial testing was carried out on English oak trees to demonstrate the approach and to assess the required computational resources. Depending on the size and complexity of the tree, leaf generation takes between 6 and 18 minutes. Various leaf area density distributions were defined, and the resulting leaf covers were compared to manual leaf harvesting measurements. The results are not conclusive, but they show great potential for the method. In the future, if our method is demonstrated to work well for TLS data from multiple tree types, the approach is likely to be very useful for 3D structure and radiative transfer simulation applications, including remote sensing, ecology and forestry, among others

Old and young bulges in late-type disk galaxies

ABRIDGED: We use HSTACS and NICMOS imaging to study the structure and colors of a sample of nine late-type spirals. We find: (1) A correlation between bulge and disks scale-lengths, and a correlation between the colors of the bulges and those of the inner disks. Our data show a trend for bulges to be more metal-enriched than their surrounding disks, but otherwise no simple age-metallicity connection between these systems; (2) A large range in bulge stellar population properties, and, in particular, in stellar ages. Specifically, in about a half of the late-type bulges in our sample the bulk of the stellar mass was produced recently. Thus, in a substantial fraction of the z=0 disk-dominated bulged galaxies, bulge formation occurs after the formation/accretion of the disk; (3) In about a half of the late-type bulges in our sample, however, the bulk of the stellar mass was produced at early epochs; (4) Even these "old" late-type bulges host a significant fraction of stellar mass in a young(er) c component; (5) A correlation for bulges between stellar age and stellar mass, in the sense that more massive late-type bulges are older than less massive late-type bulges. Since the overall galaxy luminosity (mass) also correlates with the bulge luminosity (mass), it appears that the galaxy mass regulates not only what fraction of itself ends up in the bulge component, but also "when" bulge formation takes place. We show that dynamical friction of massive clumps in gas-rich disks is a plausible disk-driven mode for the formation of "old" late-type bulges. If disk evolutionary processes are responsible for the formation of the entire family of late-type bulges, CDM simulations need to produce a similar number of initially bulgeless disks in addition to the disk galaxies that are observed to be bulgeless at z=0.Comment: ApJ in press; paper with high resolution figures available at http://www.exp-astro.phys.ethz.ch/carollo/carollo1_2006.pdf; B, I, and H surface brightness profiles published in electronic tabular for

Disk Galaxies in the Outer Local Supercluster: Optical CCD Surface Photometry and Distribution of Galaxy Disk Parameters

We report new B-band CCD surface photometry on a sample of 76 disk galaxies brighter than B_T = 14.5 mag in the Uppsala General Catalogue of Galaxies, which are confined within a volume located in the outer part of the Local Supercluster. With our earlier published I-band CCD and high S/N-ratio 21cm HI data (Lu et al. 1993), this paper completes our optical surface photometry campaign on this galaxy sample. As an application of this data set, the B-band photometry is used here to illustrate two selection effects which have been somewhat overlooked in the literature, but which may be important in deriving the distribution function of disk central surface brightness (CSB) of disk galaxies from a diameter or/and flux limited sample: a Malmquist-type bias against disk galaxies with small disk scale lengths (DSL) at a given CSB; and a disk inclination dependent selection effect that may, for example, bias toward inclined disks near the threshold of a diameter limited selection if disks are not completely opaque in optical. Taking into consideration these selection effects, we present a method of constructing a volume sampling function and a way to interpret the derived distribution function of CSB and DSL. Application of this method to our galaxy sample implies that if galaxy disks are optically thin, CSB and DSL may well be correlated in the sense that, up to an inclination-corrected limiting CSB of about 24.5 mag per square arcsec that is adequately probed by our galaxy sample, the DSL distribution of galaxies with a lower CSB may have a longer tail toward large values unless the distribution of disk galaxies as a function of CSB rises rapidly toward faint values.Comment: 27 pages including 9 figures and 2 tables. To appear in the October 20, 1998 issue of the Astrophysical Journa