674 research outputs found
Preserving a Legacy of Literary Lives: Re-connecting Patrons to one of our most Dynamic Digital Collections
This poster describes a project at West Chester University to re-digitize the Philips Autograph Library Collection. Combining the efforts of the Special Collections, Cataloging, and Interlibrary Loan Departments, the goal is to improve and enhance access to this unique and valuable WCU treasure
Pearling: stroke segmentation with crusted pearl strings
We introduce a novel segmentation technique, called Pearling, for the semi-automatic extraction of idealized models of networks of strokes (variable width curves) in images. These networks may for example represent roads in an aerial photograph, vessels in a medical scan, or strokes in a drawing. The operator seeds the process by selecting representative areas of good (stroke interior) and bad colors. Then, the operator may either provide a rough trace through a particular path in the stroke graph or simply pick a starting point (seed) on a stroke and a direction of growth. Pearling computes in realtime the centerlines of the strokes, the bifurcations, and the thickness function along each stroke, hence producing a purified medial axis transform of a desired portion of the stroke graph. No prior segmentation or thresholding is required. Simple gestures may be used to trim or extend the selection or to add branches. The realtime performance and reliability of Pearling results from a novel disk-sampling approach, which traces the strokes by optimizing the positions and radii of a discrete series of disks (pearls) along the stroke. A continuous model is defined through subdivision. By design, the idealized pearl string model is slightly wider than necessary to ensure that it contains the stroke boundary. A narrower core model that fits inside the stroke is computed simultaneously. The difference between the pearl string and its core contains the boundary of the stroke and may be used to capture, compress, visualize, or analyze the raw image data along the stroke boundary
Complex hybridization patterns in European pond turtles (Emys orbicularis) in the Pyrenean Region
Hybrid zones are natural laboratories allowing insights in genetic processes like lineage diversification, speciation and introgression. Using large sampling, 15 microsatellite loci and a mitochondrial marker, we examined the Pyrenean contact zone of three pond turtle taxa (Emys orbicularis orbicularis, E. o. galloitalica, E. o. occidentalis). The Pyrenees are a biogeographically important region separating many lineages endemic to the Iberian Peninsula from their Western European counterparts. We discovered limited admixture, reflecting a complex biogeographic scenario. Simulations using Approximate Bayesian Computing supported that E. o. orbicularis invaded the Iberian Peninsula in the Holocene, circumventing the Pyrenees along the Mediterranean coast, and hybridized in the northern peninsula with the local coastal subspecies galloitalica, and to a lesser extent, with occidentalis. While E. o. occidentalis, and in particular E. o. orbicularis, expanded their ranges considerably during Holocene warming, E. o. galloitalica remained largely confined to its former Iberian refuge. Admixture among the three taxa is surprisingly low, and a future taxonomic investigation that includes the unstudied subspecies of E. orbicularis from North Africa, Eastern Europe and Asia has to determine whether their current status properly reflects their evolutionary divergence or whether certain taxa should be regarded as full species
MicroRNA profile changes in human immunodeficiency virus type 1 (HIV-1) seropositive individuals
MicroRNAs (miRNAs) play diverse roles in regulating cellular and developmental functions. We have profiled the miRNA expression in peripheral blood mononuclear cells from 36 HIV-1 seropositive individuals and 12 normal controls. The HIV-1-positive individuals were categorized operationally into four classes based on their CD4+ T-cell counts and their viral loads. We report that specific miRNA signatures can be observed for each of the four classes
Aporte de nitrogênio por árvores madeireiras jovens em sistema integrado de produção com plátanos.
Sistemas integrados de produção são alternativas para uma agricultura mais eficiente no uso da terra e promotora de benefícios ambientais e sociais. Os plátanos, em função das suas características, podem ser explorados em associação com outras culturas de interesse econômico, sendo o arranjo produtivo dependente de fatores edafoclimáticos, mercadológicos, culturais etc. Na integração de musáceas com árvores, além dos produtos finais, pode haver outros benefícios para a economia do sistema, como o aporte de nitrogênio (N) pelo uso de leguminosas arbóreas
The problems of genetic support of dividing the black kite (Milvus migrans) into subspecies
The black kite Milvus migrans is a common bird of prey demonstrating remarkable ecological plasticity. It inhabits a variety of habitats and is an increasingly synanthropic species. The black kite is widespread in Eurasia, Africa, Australia and adjacent islands. Palearctic kites migrate to Africa, India and China in winter, but kites of Africa and Australia are partly sedentary and partly seasonal migrants. The wide range and high mobility are the reasons of a complex population structure of the black kite. Commonly five to seven M. migrans subspecies are distinguished, each of which is widespread over extensive areas and has more or less an apparent phenotype. Recently, studies of genetic differences between black kite populations started to emerge. On the grounds of earlier studies of mitochondrial and nuclear genes of this species, we check whether there is a genetic support for separation of the black kite subspecies. Recent studies of some mitochondrial loci substantiate the recognition of at least the European (M. m. migrans), Asian (M. m. lineatus and M. m. govinda), African (M. m. aegyptius and M. m. parasitus), and Australian (M. m. affinis) black kite subspecies. Furthermore, the mitochondrial haplotype difference suggests that the African yellow-billed kite, including M. m. aegyptius and M. m. parasitus, should be a separate species as already proposed, or even two separate species
LABOCA 870 micron dust continuum mapping of selected infrared-dark cloud regions in the Galactic plane
We have mapped four selected about 0.5 deg x 0.5 deg-sized fields containing
Spitzer 8-micron dark regions with APEX/LABOCA at 870 micron. Selected
positions in the fields were observed in C17O(2-1) to obtain kinematic
information. The obtained LABOCA maps are used in conjunction with the Spitzer
IR images. The total number of clumps identified in this survey is 91, out of
which 40 (44%) appear dark at 8 and 24 micron. The remaining clumps are
associated with mid-IR emission. Many of the identified clumps are massive
enough to allow high-mass star formation, and some of them already show clear
signposts of that. Seven clumps associated with extended-like 4.5 micron
emission are candidate extended green objects (EGOs). Filamentary dust "ridges"
were found towards the Spitzer bubbles N10/11 in one of our fields, which
conforms to the triggered high-mass star formation in the system. The relative
number of IR-dark and IR-bright clumps suggest that the duration of the former
stage is about 1.6x10^5 yr. The mass distribution of the total sample of
clumps, and that separately constructed for the IR-dark and IR-bright clumps,
could be fitted at the high-mass end with the power-law function dN/dlogM ~
M^(-0.8...-0.7). The C17O observation positions appear to be dominated by
non-thermal motions, and the data also revealed some potential sites of strong
CO depletion. In G11.36+0.80, which is the best example of a filamentary IRDC
in our sample, the clumps appear to be gravitationally bound. The fragmentation
of the filament can be understood in terms of a "sausage"-type fluid
instability, in agreement with the results for other IRDCs. The formation of
filamentary IRDCs might be caused by converging turbulent flows, and the same
process may play a role in exciting the fluid perturbations responsible for the
fragmentation of the clouds into clumps.Comment: 23 pages, 14 figures, and 6 tables. Accepted for publication in
Astronomy and Astrophysic
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