Applying mesh conformation on shape analysis with missing data

A mesh conformation approach that makes use of deformable generic meshes has been applied to establishing correspondences between 3D shapes with missing data. Given a group of shapes with correspondences, we can build up a statistical shape model by applying principal component analysis (PCA). The conformation at first globally maps the generic mesh to the 3D shape based on manually located corresponding landmarks, and then locally deforms the generic mesh to clone the 3D shape. The local deformation is constrained by minimizing the energy of an elastic model. An algorithm was also embedded in the conformation process to fill missing surface data of the shapes. Using synthetic data, we demonstrate that the conformation preserves the configuration of the generic mesh and hence it helps to establish good correspondences for shape analysis. Case studies of the principal component analysis of shapes were presented to illustrate the successes and advantages of our approach

The Functional Importance of Forbs in Grassland Ecosystems

Herbaceous vegetation in grassland ecosystems is characterised by grass dominance in a species-rich forb-grass mixture. Forbs (i.e. the non-graminoid herbaceous component) represent the largest proportion of total species- and functional richness, which secure important ecosystem functions. Although grasses remain the most important forage source, certain forb species provide nutritious food sources for herbivores. Moreover, forbs provide food- and habitat sources to enhance invertebrate diversity and hence, agricultural food security through the maintenance of healthy pollinator communities. Important food and medicinal sources for human livelihoods in developing countries are also largely contributed by forbs. However, the dynamics and ecology of forb species are poorly understood in rangeland systems. Increasing global pressures are threatening the hyper-diverse grassland ecosystems (including African savannas) and in particular the diversity of the forb flora. The sub-ordinate role of forbs in savanna and grassland rangeland management practices led us to accumulate evidence of important ecosystem functions and services provided by this diverse life form. In this study, we present results that were obtained from several independent studies in which forb data were collected and analysed as an equally important herbaceous life form, to contribute to our current understanding of the ecology of grassland ecosystems. Our results revealed evidence of forbs as important forage for large African mammalian herbivores, including domestic cattle, during periods when other forage resources are severely limited. However, sustained overgrazing can severely deplete forb populations and diversity. Forbs as grazing indicators have been identified as the basis of a proposed forb-condition scoring method for mesic grasslands. Furthermore, the importance of intermediate disturbances, such as moderate grazing and/or the maintenance of crop field margins were identified for invertebrate community conservation. Studies on useful indigenous plants exposed forbs as an important life form to provide food- and medicinal resources to human livelihoods in African grassland ecosystems

Azimuth axis optical alignment system Final report

Azimuth axis optical alignment system to monitor and measure attitude or angular position of remote object about azimuth axis using phase information imposed on returning beam of ligh

Red Quasars and Quasar Evolution: the Case of BALQSO FIRST J155633.8+351758

We present the first near-IR spectroscopy of the z=1.5 radio-loud BALQSO FIRST J155633.8+351758. Both the Balmer decrement and the slope of the rest-frame UV-optical continuum independently suggest a modest amount of extinction along the line of sight to the BLR (E(B-V)~0.5 for SMC-type screen extinction at the QSO redshift). The implied gas column density along the line of sight is much less than is implied by the weak X-ray flux of the object, suggesting that either the BLR and BAL region have a low dust-to-gas ratio, or that the rest-frame optical light encounters significantly lower mean column density lines of sight than the X-ray emission. From the rest-frame UV-optical spectrum, we are able to constrain the stellar mass content of the system. Comparing the maximal stellar mass with the black hole mass estimated from the bolometric luminosity of the QSO, we find that the ratio of the black hole to stellar mass may be comparable to the Magorrian value, which would imply that the Magorrian relation is already in place at z=1.5. However, multiple factors favor a much larger black hole to stellar mass ratio. This would imply that if the Magorrian relation characterizes the late history of QSOs, and the situation observed for F1556+3517 is typical of the early evolutionary history of QSOs, central black hole masses develop more rapidly than bulge masses. [ABRIDGED]Comment: 23 pages, 4 embedded postscript figures; Accepted for publication in The Astronomical Journal, December 200

Blob ejection from advection-dominated accretion flow: observational consequences

There is increasing evidence for the presence of an optically thin advection-dominated accretion flow (ADAF) in low luminosity active galactic nuclei and radio-loud quasars. The present paper is devoted to explore the fate of a blob ejected from an ADAF, and to discuss its observational consequences. It is inevitable for the ejected blob to drastically expand into its surroundings. Consequently, it is expected that a group of relativistic electrons should be accelerated, which may lead to nonthermal flares, since a strong shock will be formed by the interaction between the blob and its surroundings. Then the blob cools down efficiently, leading to the appearance of recombination lines about $10^5$s after its ejection from an ADAF. We apply this model to NGC 4258 for some observational prediction, and to PKS 2149--306 for the explanation of observational evidence. Future simultaneous observations of recombination X-ray lines and continuum emission are highly desired to test the present model.Comment: 4 pages in emulateapj.sty, no figure. Accepted by ApJ Letter

A Very Radio-Loud Narrow-Line Seyfert 1: PKS 2004-447

We have discovered a very radio-loud Narrow-Line Seyfert 1 candidate: PKS 2004-447. This Seyfert is consistent with the formal definition for NLS1s, although it does not have quite the same spectral features as some typical members of this subclass. Only ROSAT survey data is available at X-ray wavelengths, so it has not been possible to compare this source with other NLS1s at these wavelengths. A full comparison of this source with other members of the subclass will improve our physical understanding of NLS1s. In addition, using standard calculations, we estimate the central black hole to have a mass of $\sim 5 \times 10^6 M_{\odot}$. This does not agree with predictions in the literature, that radio-loud AGN host very massive black holes.Comment: 15 pages, 4 figures, accepted for publication in ApJ, minor typos change