bluuebunny/crossref_metadata_2025_split huggingface dataset:
Color image quantization for frame buffer display
Authors: Heckbert Paul 
Published: November 2005

Algorithms for adaptive, tapered quantization of color images are described. The research is motivated by the desire to display high-quality reproductions of color images with small frame buffers. It is demonstrated that many color images which would normally require a frame buffer having 15 bits per pixel can be quantized to 8 or fewer bits per pixel with little subjective degradation. In most cases, the resulting images look significantly better than those made with uniform quantization.
The color image quantization task is broken into four phases:
1) Sampling the original image for color statistics
2) Choosing a colormap based on the color statistics
3) Mapping original colors to their nearest neighbors in the colormap
4) Quantizing and redrawing the original image (with optional dither).
Several algorithms for each of phases 2-4 are described, and images created by each given.
The role of videotex (Panel Session)
Authors: Botten Brian , Norton John , Schneider Lois , Tompa Frank W. , Godfrey David , Dam Andries van 
Published: November 2005

Frank W. Tompa
Interactive videotex systems may soon emerge as a principal information, entertainment and communications medium relying heavily on computer graphics. Until now, much has been written about the image presentation and data facilities of the several current systems, but videotex literature and research is unexpectedly far removed from mainstream graphics audiences. The purpose of this panel session is therefore to narrow the gap.
In outline, the panel session includes an introduction to videotex, followed by several short presentations covering videotex graphics, experience, alternatives, and prospects.
Brian Botten
David Godfrey
John Norton
Lois Schneider
Andries van Dam
A device independent graphics imaging model for use with raster devices
Authors: Warnock John , Wyatt Douglas K. 
Published: November 2005

In building graphic systems for use with raster devices, it is difficult to develop an intuitive, device independent model of the imaging process, and to preserve that model over a variety of device implementations. This paper describes an imaging model and an associated implementation strategy that:
1. Integrates scanned images, text, and synthetically generated graphics into a uniform device independent metaphor;
2. Isolates the device dependent portions of the implementation to a small set of primitives, thereby minimizing the implementation cost for additional devices;
3. Has been implemented for binary, grey-scale, and full color raster display systems, and for high resolution black and white printers and color raster printers.
Gaze-orchestrated dynamic windows
Authors: Bolt Richard A. 
Published: November 2005

Consider a large-format display before the user, bearing a multiplicity of “windows,” like little movies, the majority dynamic and in color. There are upwards of 20 windows, say, more than a person can ordinarily absorb at once. Some of the windows come and go, reflecting their nature as direct TV linkages into real-time, real-world events. Others are non-real-time, some dynamic, others static but capable of jumping into motion.
Such an ensemble of information inputs reflects the managerial world of the top-level executive of the not too distant electronic future: a world of brevity, fragmentation, variety, above all one of an overwhelming onslaught of events.

The multiplicity and simultaneity of such a display situation ordinarily would make coping with it untenable. The intent of the reported research is to introduce order and control, through the creation of a dynamic,
gaze-interactive
interface.

Making the behavior and reactivity of the “windows” contingent upon measured eyemovements - the point-of-regard of the observer - aims both to help the observer to cope with the onslaught of events on the one hand, yet enable on the other hand continuing close contact with that everchanging ensemble.
A simulation of such a world is described and demonstrated in the composite medium of computer, videodisc, and video special effects. Eye-tracking technology, integrated with speech and manual inputs, controls the display's visual dynamics, and orchestrates its sound accompaniments. All elements are combined to form a testbed for the conception generally, and to explore the associated human factors and stagecraft.
An application of color graphics to the display of surface curvature
Authors: Dill John C. 
Published: November 2005

In developing a mathematical representation for a surface, designers currently must use line drawing graphics to examine the curvature of a line in a plane, a two-dimensional analysis. By combining a result from differential geometry with the use of color raster graphics, the method described in this paper provides a means for the designer to examine surface curvature, a three-dimensional analysis. In particular, a formulation for the Gaussian and average curvatures is given and it is shown how these indicate the presence or absence of protrusions, hollows, etc. in a surface, i.e., how, where, and by how much the surface curves.
Showing a fourth variable, curvature in this case, over a three-dimensional surface is difficult, if not impossible with traditional line drawing computer graphics. The method described solves this problem by using color as a fourth dimension. Examples are given, including both known shapes (torus) and automotive parts (hood, fender).
An integrated system for creating and presenting complex computer-based documents
Authors: Feiner Steven , Nagy Sandor , Van Dam Andries 
Published: November 2005

An experimental system is described for the design, development, and presentation of computer-based documents that combine pictures and text on a high-resolution raster color display. Such documents can be used, for example, for maintenance and repair tasks or computer-aided instruction.

Documents
are directed graphs whose nodes we refer to as
pages
, in analogy to the pages of a paper book. A page includes a set of simultaneously displayed pictures, actions (procedures and processes) triggered when the page is accessed or when pickable picture elements on it are selected, and indexing information. Pages may be nested arbitrarily deeply in
chapters
that serve much the same organizing function as those of conventional books.

The system is comprised of separate programs for laying out and drawing pictures, for graphically specifying the contents of pages, chapters, and their interconnections, and for displaying the document for user interaction.
Examples are given from a prototype document for the maintenance and repair of computerized numerical control equipment. Emphasis was placed on designing actions for simple realtime animation (both by color table techniques and by transforming named primitives and manipulating their attributes), and for finding one's way around the document (displays include: a “timeline” of recently visited pages, immediate predecessor and successor pages, sibling pages and their interconnections, and those pages satisfying key-word retrieval requests).
Two aspects of domain designing
Authors: Rockwood Alyn P. , Jensen Thomas W. 
Published: November 2005

In 1965, Shepard introduced a general interpolation formula for arbitrarily spaced data over any finite dimensional Euclidean space. The deficiencies in his initial results have been corrected and later derivations have been widely applied to surface fitting problems in aviation design and geology.
This paper describes a new research direction in Shepard's method and a new application to computer graphics. In the first, the convex weighting functions are generalized by the creation of a user-defined mathematical domain which is independent of the surface. In the second, the original formula is applied to blend mapping projections for aviation visual simulation and an algorithm for rapid evaluation is presented.
ANSI X3H3 Technical Committee on Computer Graphics (Panel Discussion)
Authors: Puk Richard , Reed Ted , Skall Mark , Wright Tom , Bono Peter 
Published: November 2005

Several members of the American National Standards Institute (ANSI) Technical Committee X3H3 on Computer Graphics will present current issues of the standardization effort. The focus of the discussion will be the technical content of these issues.
The purpose of the panel discussion is to encourage technical dialogue between X3H3 participants and interested parties outside of X3H3. To that end, the presentations will describe major areas of concern, avenues of attack, and proposed solutions.
A software test-bed for the development of 3-D raster graphics systems
Authors: Whitted Turner , Weimer David M. 
Published: November 2005

We describe a set of utility routines for 3-D shaded display which allow us to create raster scan display systems for various experimental and production applications. The principal feature of this system is a flexible scan conversion processor that can simultaneously manage several different object types.
Communications between the scan conversion routine and processes which follow it in the display pipeline can be routed through a structure called a “span buffer” which retains some of the high resolution, three dimensional data of the object description and at the same time has the characteristics of a run length encoded image.
Extended safe havens and between-group dispersal of helpers in a cooperatively breeding cichlid
Authors: Bergmüller Ralph , Taborsky Michael , Peer Katharina , Heg Dik 
Published: November 2005

AbstractIn cooperative breeders, between-group dispersal of helpers is expected to occur if it increases their fitness. Genetic data suggest that helpers in the cooperatively breeding Lake Tanganyika cichlid Neolamprologus pulcher occasionally migrate into nearby groups where they again become helpers. We studied in the field how and why helpers migrate between groups by recording their ranging and social behaviours. We found that helpers spent 5.3% of their time visiting other groups, where they received similar low levels of aggression as within their home group. Large helpers visited other groups more often than small helpers and helpers visited other groups more frequently when the queue in their home group was large, suggesting that helpers with low chances to inherit the territory search for alternatives. Our data show that helpers may use other groups' territories as a refuge, as helpers actively sought shelter within territories of neighbouring groups when we experimentally increased the perceived risk of staying in their home territory. We observed two attempted and one successful case of 'voluntary' (i.e., strategic) between-group dispersal, and experimentally induced three helpers to disperse into other groups. By regular visits, helpers appear to establish familiarity and social relationships with nearby groups, which serve as 'extended safe havens' to hide from predators. In the long run frequent visiting behaviour may facilitate between group dispersal.
Contrasting effects of reduced incubation cost on clutch attendance by male and female European starlings
Authors: van Overveld Thijs , Magrath Michael J.L. , Komdeur Jan 
Published: November 2005

AbstractIn biparental birds, the relative contribution of the sexes to parental care can be viewed as a co-operative equilibrium that reflects the relative costs and benefits to each parent. If there are asymmetries in these costs or benefits, then any changes to the cost of care could result in a corresponding adjustment to their relative contribution. Incubation is a parental activity, shared in many species, which is costly both in terms of energy expenditure and time. In this study we manipulated the cost of incubation for pairs of European starlings (Sturnus vulgaris) by experimentally warming selected clutches to examine how this affected attendance by each parent. We found that total nest attendance did not differ between heated and control nests, although there was some evidence among heated nests that attendance declined with increasing effectiveness of the heater. Furthermore, relative male contribution was greater at heated than control nests resulting from the net effect of females tending to reduce, and males increase, attendance. We suggest that this shift in relative attendance may have been observed because females have a more developed brood patch and are more sensitive and responsive to clutch temperature than males. Consequently, females tended to reduce attendance at heated nests while males, with less reliable information on the clutch's thermal status, increased attendance to compensate for the reduction by the female. We also found that females at heated nests were lighter than at control nests, possibly because they were able to shed the additional fat reserves, a characteristic of incubating birds, earlier than females at control nests. We suggest that adjustment of clutch temperature in biparental species provides a valuable approach to investigating factors, including functional differences, asymmetries in brood value, and parental negotiation rules, that shape the roles of the sexes in incubation.
Size differences within a dominance hierarchy influence conflict and help in a cooperatively breeding cichlid
Authors: Bender Nicole , Hamilton Ian M. , Heg Dik 
Published: November 2005

AbstractIn size-structured groups, conflict over rank, resources or access to breeding opportunities is expected to be greatest among individuals that are similar in size. We tested this general prediction using the cooperatively breeding African cichlid, Neolamprologus pulcher. We predicted that, when size differences between group members were small, we would observe some or all of: increased aggression, increased submissive behaviour, increased help by subordinates or avoidance of dominants by subordinates. We created standardised groups each with a breeder male and female and a large and small helper (both males). The size of all group members was kept constant, with the exception of the breeder males, which were either only slightly larger than the largest helper or much larger. This created either large or small size differences between breeder males and the large helper (the 2nd ranked male in the group). We found that large helpers showed more submissive behaviours, reduced affiliative behaviour and kept further from breeding sites when male breeders were small. We did not find a consistent influence of breeder size on aggression. Together, these results support the prediction that conflict between breeder and helper is increased when breeders are small, but that this conflict is expressed through changes in submissive and affiliative behaviours and in space use rather than aggression. In contrast to our predictions, large helpers increased helping (territorial defence) when the male breeder was large; the reasons for this are unclear.
No evidence for adaptive suppression of joint laying by dominant female Seychelles warblers: an experimental study
Authors: Komdeur Jan 
Published: November 2005

AbstractSeveral theoretical frameworks exist for explaining variation in reproductive allocation between same-sex individuals living within social groups. To determine this adequately, we need to know which party is more able to manipulate reproduction of the other. Theoretical models often sidestep this problem by making the assumption that dominants either have complete or partial control of reproduction by subordinates. This study clearly indicates that in the cooperatively breeding Seychelles warbler (Acrocephalus sechellensis) this assumption is not met. Seychelles warblers occupy year-round territories of different quality (measured as amount of insect food available). Joint laying, in which the dominant and subordinate females lay eggs in the same nest, decreases the fitness of primary females on low-quality territories, but not on high-quality territories. This study found good experimental evidence that dominant females on low-quality territories have no modes to suppress or prevent subordinate females from joint laying: (i) The frequency of joint laying in multi-female groups is independent of territory quality; (ii) There is no aggression among females at the nest around the time of egg laying at either low- or high-quality territories; (iii) Dominant females do not remove the other female's egg or experimentally introduced eggs, before or after laying their own. (iv) Dominant females do not reject an experimentally introduced egg through nest desertion. Given the absence of reproductive control, increased attention to alternative models of reproductive partitioning in vertebrate societies is needed and a realistic model has to take into account interactions within the sexes.
Large group size yields group stability in the cooperatively breeding cichlid Neolamprologus pulcher
Authors: Taborsky Michael , Brouwer Lyanne , Heg Dik , Bachar Zina 
Published: November 2005

AbstractGroup size has been shown to positively influence survival of group members in many cooperatively breeding vertebrates, including the Lake Tanganyika cichlid Neolamprologus pulcher, suggesting Allee effects. However, long-term data are scarce to test how these survival differences translate into changes in group extinction risk, group size and composition. We show in a field study of 117 groups from six different colonies (three from two populations each), that group size critically influences these parameters between years. Within one year, 34% of the groups went extinct. Group size correlated positively between years and large groups did not go extinct. The latter were more likely to contain small helpers the subsequent year, which is a cumulative measure of the previous months' reproductive success. Finally, there was a tendency that large groups were more likely to contain a breeding male and female still a year after the first check. The breeder male size, breeder female size, and largest helper size did not influence these parameters, and also did not correlate with the sizes of these categories of fish after one year. This suggests that group size, and not the body size or fighting ability of group members, was the critical variable determining the success of groups. In total, seven groups had fused with other groups between years. To our knowledge, this is the first study showing long-term benefits of large group size in a cooperatively breeding fish. We discuss the importance of differential survival and dispersal of group members for the demonstrated group size effects.
Reduced retention of radioprotective hematopoietic cells within the bone marrow microenvironment in CXCR4–/– chimeric mice
Authors: Foudi Adlen , Jarrier Peggy , Zhang Yanyan , Wittner Monika , Geay Jean-Francois , Lecluse Yann , Nagasawa Takashi , Vainchenker William , Louache Fawzia 
Published: November 2005

AbstractThe physiologic role of CXCR4 on hematopoietic stem/progenitor cells (HSPCs) is not fully understood. Here, we show that radioprotection of lethally irradiated mice by embryonic day 14.5 (E14.5) CXCR4–/– fetal liver (FL) cells was markedly impaired when compared with CXCR4+/+ counterparts, but this defect was rescued when hosts were engrafted with high cell numbers. This quantitative defect contrasted with a similar content in hematopoietic colony-forming cells (CFCs), splenic colony-forming units (CFUs-S), and Lin– Sca-1+ c-kit+ cells in E14.5 CXCR4–/– and CXCR4+/+ livers. In addition, the homing of HSPCs in the bone marrow was not altered as detected with a CFSE-staining assay. In contrast, a 30-fold increase in CFCs was seen in the circulation of mice stably reconstituted with CXCR4–/– FL cells and this increment was already observed before hematopoiesis had reached a steady-state level. Together, the data strongly suggest that impaired retention may, at least in short-term hematopoietic reconstitution, lead to a diminution in the number of available progenitors required for radioprotection.
Species- and cell type-specific interactions between CD47 and human SIRPα
Authors: Subramanian Shyamsundar , Parthasarathy Ranganath , Sen Shamik , Boder Eric T. , Discher Dennis E. 
Published: November 2005

AbstractCD47 on red blood cells (RBCs) reportedly signals “self” by binding SIRPα on phagocytes, at least in mice. Such interactions across and within species, from mouse to human, are not yet clear and neither is the relation to cell adhesion. Using human SIRPα1 as a probe, antibody-inhibitable binding to CD47 was found only with human and pig RBCs (not mouse, rat, or cow). In addition, CD47-mediated adhesion of human and pig RBCs to SIRPα1 surfaces resists sustained forces in centrifugation (as confirmed by atomic force microscopy) but only at SIRPα-coating densities far above those measurable on human neutrophils, monocytes, and THP-1 macrophages. While interactions strengthen with deglycosylation of SIRPα1, low copy numbers explain the absence of RBC adhesion to phagocytes under physiologic conditions and imply that the interaction being studied is not responsible for red cell clearance in humans. Evidence of clustering nonetheless suggests mechanisms of avidity enhancement. Finally, using the same CD47 antibodies and soluble SIRPα1, bone marrow-derived mesenchymal stem cells were assayed and found to display CD47 but not bind SIRPα1 significantly. The results thus demonstrate that SIRPα-CD47 interactions, which reportedly define self, exhibit cell type specificity and limited cross-species reactivity. (Blood. 2006;107:2548-2556)
Multiplicity and plasticity of natural killer cell signaling pathways
Authors: Chiesa Sabrina , Mingueneau Michael , Fuseri Nicolas , Malissen Bernard , Raulet David H. , Malissen Marie , Vivier Eric , Tomasello Elena 
Published: November 2005

AbstractNatural killer (NK) cells express an array of activating receptors that associate with DAP12 (KARAP), CD3ζ, and/or FcRγ ITAM (immunoreceptor tyrosine-based activation motif)–bearing signaling subunits. In T and mast cells, ITAM-dependent signals are integrated by critical scaffolding elements such as LAT (linker for activation of T cells) and NTAL (non–T-cell activation linker). Using mice that are deficient for ITAM-bearing molecules, LAT or NTAL, we show that NK cell cytotoxicity and interferon-γ secretion are initiated by ITAM-dependent and -independent as well as LAT/NTAL-dependent and -independent pathways. The role of these various signaling circuits depends on the target cell as well as on the activation status of the NK cell. The multiplicity and the plasticity of the pathways that initiate NK cell effector functions contrast with the situation in T cells and B cells and provide an explanation for the resiliency of NK cell effector functions to various pharmacologic inhibitors and genetic mutations in signaling molecules.