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Cross-reactive antibodies produced by a mammalian host during infection by a particular microparasitic strain usually have the effect of reducing the probability of the host being infected by a different, but closely related, pathogen strain. Such cross-reactive immunological responses thereby induce between-strain competition within the pathogen(More)
The effects of selection by host immune responses on transmission dynamics was analyzed in a broad class of antigenically diverse pathogens. Strong selection can cause pathogen populations to stably segregate into discrete strains with nonoverlapping antigenic repertoires. However, over a wide range of intermediate levels of selection, strain structure is(More)
The design of role-playing games (RPGs) is very complex, involving an intricate interweaving of narrative, quest design, and level design. As an important means for conveying the game's story, quests dictate the setting and contents of levels. Levels provide challenges for the player to overcome in the service of completing quests, and their structure can(More)
We show that the Dual-Tree Complex Wavelet Transform (DTCWT) [1] is a well-suited basis to detect salient keypoints in images as it is: directionally selective, smoothly shift invariant, optimally decimated at coarse scales, invertible (no loss of information) and fast to compute. It is therefore more suitable than the Discrete Wavelet Transform for content(More)
In this paper, we introduce a new multiscale representation for 2-D images named the Inter-Coefficient Product (ICP). The ICP is a decimated pyramid of complex values based on the Dual-Tree Complex Wavelet Transform (DT-CWT). The complex phases of its coefficients correspond to the angles of dominant directional features in their support regions. As a(More)
BACKGROUND Since 1987, the Defense Personnel Security Research Center (PERSEREC) has maintained a database on espionage by American citizens based largely on open sources, and has collected files on each of the 173 individuals in the database. Espionage by Americans is the worst outcome for the personnel security system that works to reduce the risk of(More)
The Curiosity rover discovered fine-grained sedimentary rocks, which are inferred to represent an ancient lake and preserve evidence of an environment that would have been suited to support a martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and(More)
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of(More)
Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a(More)