In the title compound, C21H11N5S, the pheno-thia-zine unit has a butterfly structure, and the central six-membered ring adopts a boat conformation. The dihedral angle between the benzene rings is 127.64 (6)°, which is smaller than those reported for similar compounds because of the steric repulsion between the pheno-thia-zine and its tetra-cyano-1,3-butadiene substituent. The di-cyano-vinyl gro...

The rate at which genomes diverge during speciation is unknown, as are the physical dynamics of the process. Here, we compare full genome sequences of 32 butterflies, representing five species from a hybridizing Heliconius butterfly community, to examine genome-wide patterns of introgression and infer how divergence evolves during the speciation process. Our analyses reveal that initial diverge...

Associations between biological traits of animals and climate are well documented by physiological and local-scale studies. However, whether an ecophysiological phenomenon can affect large-scale biogeographical patterns of insects is largely unknown. Insects absorb energy from the sun to become mobile, and their colouration varies depending on the prevailing climate where they live. Here we sho...

Two major approaches address the need to predict species distributions in response to environmental changes. Correlative models estimate parameters phenomenologically by relating current distributions to environmental conditions. By contrast, mechanistic models incorporate explicit relationships between environmental conditions and organismal performance, estimated independently of current dist...

Migratory monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate to their overwintering grounds in Mexico. Although polarized light is one of the celestial cues used for orientation, the spectral content (color) of that light has not been fully explored. We cloned the cDNAs of three visual pigment-encoding opsins (ultraviolet [UV], blue, and long wavelength) and f...

On the wavelength-division multiplexing (WDM) optical networks, when the number of wavelengths for realizing a set R of routing requests is beyond the number of wavelengths supported by an optical link, multiple rounds of routing for R are required. R = {(u, v)} is a set of multicasts if each source u sends a message to at least one destination v and each destination v receives a message from e...

Concerns about the potential toxicity of pollen from genetically modified maize on neighbouring butterflies prompted urgent studies, reports Nigel Williams.

That the flap of a butterfly’s wing might lead to a storm or other event halfway around the globe is a popular image used to introduce chaos theory. But two small lepidopterans appear to have played a major part in the scrapping of plans to build a new nuclear power station on a shingle bank in the south-east of England, which is becoming an increasing focus in the International Year of Biodive...

This paper presents a general framework for the computation of projective invariants of arbitrary degree of freedom (dof) trihedral polyhedra. We show that high dof. figures can be broken down into sets of connected four dof. polyhedra, for which known invariants exist. Although the more general shapes do not possess projective properties as a whole (when viewed by a single camera), each subpar...

The paper introduces the butterfly factorization as a data-sparse approximation for the matrices that satisfy a complementary low-rank property. The factorization can be constructed efficiently if either fast algorithms for applying the matrix and its adjoint are available or the entries of the matrix can be sampled individually. For an N ×N matrix, the resulting factorization is a product of O...