Teleportation of geometric structures in 3D

Simplest quantum teleportation algorithms can be represented in geometric terms in spaces of dimensions 3 (for real state-vectors) and 4 (for complex state-vectors). The geometric representation is based on geometric-algebra coding, a geometric alternative to the tensor-product coding typical of quantum mechanics. We discuss all the elementary ingredients of the geometric version of the algorithm: Geometric analogs of states and controlled Pauli gates. Fully geometric presentation is possible if one employs a nonstandard representation of directed magnitudes, formulated in terms of colors defined via stereographic projection of a color wheel, and not by means of directed volumes.Comment: typos corrected, one plot remove

Threat-sensitive anti-predator defence in precocial wader, the northern lapwing Vanellus vanellus

Birds exhibit various forms of anti-predator behaviours to avoid reproductive failure, with mobbing—observation, approach and usually harassment of a predator—being one of the most commonly observed. Here, we investigate patterns of temporal variation in the mobbing response exhibited by a precocial species, the northern lapwing (Vanellus vanellus). We test whether brood age and self-reliance, or the perceived risk posed by various predators, affect mobbing response of lapwings. We quantified aggressive interactions between lapwings and their natural avian predators and used generalized additive models to test how timing and predator species identity are related to the mobbing response of lapwings. Lapwings diversified mobbing response within the breeding season and depending on predator species. Raven Corvus corax, hooded crow Corvus cornix and harriers evoked the strongest response, while common buzzard Buteo buteo, white stork Ciconia ciconia, black-headed gull Chroicocephalus ridibundus and rook Corvus frugilegus were less frequently attacked. Lapwings increased their mobbing response against raven, common buzzard, white stork and rook throughout the breeding season, while defence against hooded crow, harriers and black-headed gull did not exhibit clear temporal patterns. Mobbing behaviour of lapwings apparently constitutes a flexible anti-predator strategy. The anti-predator response depends on predator species, which may suggest that lapwings distinguish between predator types and match mobbing response to the perceived hazard at different stages of the breeding cycle. We conclude that a single species may exhibit various patterns of temporal variation in anti-predator defence, which may correspond with various hypotheses derived from parental investment theory

Phase-space formulation of quantum mechanics and quantum state reconstruction for physical systems with Lie-group symmetries

We present a detailed discussion of a general theory of phase-space distributions, introduced recently by the authors [J. Phys. A {\bf 31}, L9 (1998)]. This theory provides a unified phase-space formulation of quantum mechanics for physical systems possessing Lie-group symmetries. The concept of generalized coherent states and the method of harmonic analysis are used to construct explicitly a family of phase-space functions which are postulated to satisfy the Stratonovich-Weyl correspondence with a generalized traciality condition. The symbol calculus for the phase-space functions is given by means of the generalized twisted product. The phase-space formalism is used to study the problem of the reconstruction of quantum states. In particular, we consider the reconstruction method based on measurements of displaced projectors, which comprises a number of recently proposed quantum-optical schemes and is also related to the standard methods of signal processing. A general group-theoretic description of this method is developed using the technique of harmonic expansions on the phase space.Comment: REVTeX, 18 pages, no figure

Variation of Basal EROD Activities in Ten Passerine Bird Species – Relationships with Diet and Migration Status

Inter-specific differences in animal defence mechanisms against toxic substances are currently poorly understood. The ethoxyresorufin-O-deethylase (EROD) enzyme plays an important role in defence against toxic chemicals in a wide variety of animals, and it is an important biomarker for environmental contamination. We compared basal hepatic EROD activity levels among ten passerine species to see if there is inter-specific variation in enzyme activity, especially in relation to their diet and migration status. Migratory insectivores showed higher EROD activity compared to granivores. We hypothesize that the variable invertebrate diet of migratory insectivores contains a wider range of natural toxins than the narrower diet of granivores. This may have affected the evolution of mixed function oxidases (MFO) system and enzyme activities. We further tested whether metabolic rates or relative liver size were associated with the variation in detoxification capacity. We found no association between EROD activity and relative (per mass unit) basal metabolic rate (BMR). Instead, EROD activity and relative liver mass (% of body mass) correlated positively, suggesting that a proportionally large liver also functions efficiently. Our results suggest that granivores and non-migratory birds may be more vulnerable to environmental contaminants than insectivores and migratory birds. The diet and migration status, however, are phylogenetically strongly connected to each other, and their roles cannot be fully separated in our analysis with only ten passerine species

Influence of Growth Conditions and Doping on Physical Properties of Gallium Antimonide Single Crystals

Gallium antimonide (GaSb) single crystals were grown by modified Czochralski method integrated with in situ synthesis in a flowing atmosphere of pure hydrogen. The influence of charge material purity as well as other technological parameters on GaSb crystals quality was investigated. High purity undoped GaSb single crystals were grown with residual acceptors concentration < 1.4 × $10^{17} cm^{-3}$ and high mobility ≈ 690 $cm^2$/Vs (at 300 K). P-type GaSb crystals were doped with silicon (carrier concentration up to 2 × $10^{19} cm^{-3}$) and with zinc (up to 1 × $10^{19} cm^{-3}$). Tellurium doped n-type GaSb single crystals were obtained with concentration up to 2 × $10^{18} cm^{-3}$. Electrical parameters were investigated by the Hall measurements (300 K and 77 K). Temperature dependent Hall measurements (10 ÷ 300 K) were used to compare the quality of undoped GaSb (obtained from Sb of different purity). Dopant concentration was estimated by glow discharge mass spectroscopy analysis. Axial and radial distribution of carrier concentration were investigated especially for Te-doped crystals (low segregation coefficient of Te in GaSb). Great contribution of compensation and self-compensation mechanisms is shown especially for the beginning part of grown crystals and for low Te-doping level. Radial distribution of physical properties for crystals grown in 〈100〉 direction is not axisymmetrical especially for doped GaSb crystals

Doping gallium antimonide single crystals for n-type and p-type conductivity

Monokryształy antymonku galu domieszkowane na typ przewodnictwa n oraz na typ p orientacji otrzymane zostały zmodyfikowaną metodą Czochralskiego zintegrowaną z syntezą in-situ. Zbadano wpływ parametrów technologicznych na skuteczność procesu domieszkowania i dobrano parametry w celu otrzymania monokryształów o pożądanym typie przewodnictwa oraz koncentracji nośników. Uzyskano monokryształy GaSb typu n (domieszkowane tellurem) o koncentracji nośników w zakresie od 1 x 10[indeks górny]17 do 1 x 10[indeks górny]18 cm. Otrzymane monokryształy GaSb typu p posiadały koncentrację w zakresie od 4 x 10[indeks górny]17 do 2 x 10[indeks górny]19 cm³ (domieszkowane krzemem) oraz koncentrację od 2 x 10[indeks górny]18 do 1 x 10[indeks górny]19 cm³ (domieszkowane cynkiem). Zbadano wpływ koncentracji domieszki (Te, Zn, Si), jak też sposobu jej wprowadzania (Si), na własności elektryczne otrzymanych kryształów.Gallium antimonide (GaSb) single crystals with n--type or p-type conductivity were grown by modified Czochralski method integrated with in-situ synthesis. The influence of technological parameters on doping process and its effectivity was investigated. Tellurium doped n-type GaSb single crystals were obtained with carrier concentration from 1 x 10[sup]17 to 1 x 10[sup]18 cm-³. GaSb p-type single crystals were obtained with carrier concentration from 4 x 10[sup]17 to 2 x 10[19] cm-³ (Si-doped) and from 2 x 10[sup]18 to 1 x 10[sup]19 cm-³ (Zn-doped). Dopant concentration was estimated by GDMS analysis