32,751 research outputs found
Critical exponents for random knots
The size of a zero thickness (no excluded volume) polymer ring is shown to
scale with chain length in the same way as the size of the excluded volume
(self-avoiding) linear polymer, as , where . The
consequences of that fact are examined, including sizes of trivial and
non-trivial knots.Comment: 4 pages, 0 figure
Spiniferaphonte, a new genus of Laophontidae (Copepoda: Harpacticoida), with notes on the occurrence of processes on the caudal rami
A new genus and species of Laophontidae, Spiniferaphonte ornata n. gen., n. sp., is described from the coast of Kenya. The new genus is closely related to Laophontina and Wellsiphontina as shown by the following synapomorphies: a denticulate operculum, a sexually dimorphic P4 exopod (reduced chaetotaxy of the ultimate segment in the male), and the absence of sexual dimorphism in the P2 and P3 endopods. The two-segmented exopod of PI and the presence of a seta on the endopodal part of the male P5 are plesiomorphies indicating that the new genus represents a separate lineage within this group. The proposal of the new genus Spiniferaphonte is supported by the following autapomorphies: three smooth setae on the female P5 exopod and a robust, dorsally bent, and strongly sclerotised caudal seta V. Within the Laophontidae, it is striking that the presence of distinct, thorn-like processes on the caudal rami is limited to interstitial genera. Distinct processes on the proximal segments of the antennule and a proximally thickened caudal seta V also appear to be associated with this interstitiality. These structures may play a role in the movement and the anchoring of the animals in their interstitial habitat
Monopoles and flux strings from SU(2) adjoint scalars
We construct, in an SU(2) gauge theory with two adjoint scalars, flux strings
with monopoles attached at the ends. One scalar breaks SU(2) to U(1) and
produces monopoles, the other then breaks the U(1) and produces strings.
Dualizing, we write the theory in terms of effective string variables and show
that the flux in the string is exactly saturated by the monopoles at the ends.Comment: 12 pp. v2: added several references and reworded some statement
Approaches to Interpreter Composition
In this paper, we compose six different Python and Prolog VMs into 4 pairwise
compositions: one using C interpreters; one running on the JVM; one using
meta-tracing interpreters; and one using a C interpreter and a meta-tracing
interpreter. We show that programs that cross the language barrier frequently
execute faster in a meta-tracing composition, and that meta-tracing imposes a
significantly lower overhead on composed programs relative to mono-language
programs.Comment: 33 pages, 1 figure, 9 table
Review of the New World genera of the Leafhopper Tribe Erythroneurini (Hemiptera: Cicadellidae: Typhlocycbinae)
The genus-level classification of New World Erythroneurini is revised based on results of a phylogenetic
analysis of 100 morphological characters. The 704 known species are placed into 18
genera. Erasmoneura Young and Eratoneura Young, previously treated as subgenera of Erythroneura
Fitch, and Erythridula Young, most recently treated as a subgenus of Arboridia Zachvatkin,
are elevated to generic status. Three species previously included in Erasmoneura are placed in a
new genus, Rossmoneura (type species, Erythroneura tecta McAtee). The concept of Erythroneura
is thereby narrowed to include only those species previously included in the nominotypical
subgenus. New World species previously included in Zygina Fieber are not closely related to the
European type species of that genus and are therefore placed in new genera. Neozygina, n. gen.,
based on type species Erythroneura ceonothana Beamer, includes all species previously included
in the ???ceonothana group???, and Zyginama, n. gen., based on type species Erythroneura ritana
Beamer, includes most species previously included in the ???ritana group??? of New World Zygina.
Five additional new genera are described to include other previously described North American
Erythroneurini: Hepzygina, n. gen., based on type species Erythroneura milleri Beamer and also
including E. aprica McAtee; Mexigina, n. gen., based on type species Erythroneura oculata McAtee;
Nelionidia, n. gen., based on type species N. pueblensis, n. sp., three additional new species,
and Erythroneura amicis Ross; Neoimbecilla, n. gen., based on type species Erythroneura kiperi
Beamer and one new species; and Illinigina, n. gen., based on type species Erythroneura illinoiensis
Gillette. Five new genera, based on previously undescribed species, are also recognized:
Aztegina, n. gen, based on A. punctinota, n. sp., from Mexico; Amazygina, n. gen., based on type
species A. decaspina, n. sp., and three additional new species from Ecuador; Hamagina, n. gen.,
based on type species H. spinigera, n. sp., and two additional new species from Peru and Ecuador;
Napogina, n. gen., based on type species N. recta, n. sp., and one additional new species from
Ecuador; Perugina, n. gen., based on type species P. denticula, n. sp., from Peru; and Spinigina, n.
gen., based on type species S. hirsuta, n. sp., and an additional new species from Peru. Phylogenetic
analysis suggests that the New World Erythroneurini consist of three lineages resulting from
separate invasions from the Old World.published or submitted for publicationis peer reviewe
Conceptual painting
Conceptual Painting is an essay that examines if the notion of conceptual painting is a misnomer or if painting is a conceptual approach to art, akin to other mediums. It looks at this through 3 artists, Ben Cook, Pavel Buchler and Anikam Toren
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