388 research outputs found
Quantum entanglement and spin control in silicon nanocrystal
Selective coherence control and electrically mediated exchange coupling of
single electron spin between triplet and singlet states using numerically
derived optimal control of proton pulses is demonstrated. We obtained spatial
confinement below size of the Bohr radius for proton spin chain FWHM. Precise
manipulation of individual spins and polarization of electron spin states are
analyzed via proton induced emission and controlled population of energy shells
in pure 29Si nanocrystal. Entangled quantum states of channeled proton
trajectories are mapped in transverse and angular phase space of 29Si axial
channel alignment in order to avoid transversal excitations. Proton density and
proton energy as impact parameter functions are characterized in single
particle density matrix via discretization of diagonal and nearest off-diagonal
elements. We combined high field and low densities (1 MeV/92 nm) to create
inseparable quantum state by superimposing the hyperpolarizationed proton spin
chain with electron spin of 29Si. Quantum discretization of density of states
(DOS) was performed by the Monte Carlo simulation method using numerical
solutions of proton equations of motion. Distribution of gaussian coherent
states is obtained by continuous modulation of individual spin phase and
amplitude. Obtained results allow precise engineering and faithful mapping of
spin states. This would provide the effective quantum key distribution (QKD)
and transmission of quantum information over remote distances between quantum
memory centers for scalable quantum communication network. Furthermore,
obtained results give insights in application of channeled protons subatomic
microscopy as a complete versatile scanning-probe system capable of both
quantum engineering of charged particle states and characterization of quantum
states below diffraction limit linear and in-depth resolution.Comment: 30 pages, 6 figure
Global stability of the coexistence equilibrium for a general class of models of facultative mutualism
Many models of mutualism have been proposed and studied individually. In this paper, we develop a general class of models of facultative mutualism that covers many of such published models. Using mild assumptions on the growth and self-limiting functions, we establish necessary and sufficient conditions on the boundedness of model solutions and prove the global stability of a unique coexistence equilibrium whenever it exists. These results allow for a greater flexibility in the way each mutualist species can be modelled and avoid the need to analyse any single model of mutualism in isolation. Our generalization also allows each of the mutualists to be subject to a weak Allee effect. Moreover, we find that if one of the interacting species is subject to a strong Allee effect, then the mutualism can overcome it and cause a unique coexistence equilibrium to be globally stable
Anger Control
This study was designed to assess the efficiency of anger control training with twenty-three institutionalized male delinquents evidencing verbal and physical aggression. The study employed a two group crossover design. After an initial test session assessing anger with a variety of measures, the immediate treatment group received anger control training. Following this training both groups participated in a test session. The delayed treatment group then received training and both groups were finally tested a third time. For a number of measures, both groups showed significant differences between the first and the second testing sessions. However no significant differences could be attributed to the anger control training
Characterizing Idiomatic Organization in Music: A Theory and Case Study of Musical Affordances
A theory of idiomaticism is developed and illustrated using music for B-
flat valve trumpet. Physical measures were collected from two trumpet performers and
used to construct a computer model of the instrument/performer. Using this model,
several works composed by both trumpet virtuosi and non-trumpet players were
analyzed. A conceptual distinction is made between measures of performance difficulty
(how hard it is to play a particular passage) and measures of performance idiomaticism
(how well suited a passage is to a specific instrument). Methods for characterizing both
difficulty and idiomaticism are described. In general, the results suggest that detailed
modeling of the mechanics of performance can help to pinpoint aspects of musical
organization that arise from performance idioms or affordances. Repercussions for
ethnomusicology, historical musicology and music analysis are discussed
Learning mitigates genetic drift.
Genetic drift is a basic evolutionary principle describing random changes in allelic frequencies, with far-reaching consequences in various topics ranging from species conservation efforts to speciation. The conventional approach assumes that genetic drift has the same effect on all populations undergoing the same changes in size, regardless of different non-reproductive behaviors and history of the populations. However, here we reason that processes leading to a systematic increase of individuals` chances of survival, such as learning or immunological memory, can mitigate loss of genetic diversity caused by genetic drift even if the overall mortality rate in the population does not change. We further test this notion in an agent-based model with overlapping generations, monitoring allele numbers in a population of prey, either able or not able to learn from successfully escaping predators' attacks. Importantly, both these populations start with the same effective size and have the same and constant overall mortality rates. Our results demonstrate that even under these conditions, learning can mitigate loss of genetic diversity caused by drift, by creating a pool of harder-to-die individuals that protect alleles they carry from extinction. Furthermore, this effect holds regardless if the population is haploid or diploid or whether it reproduces sexually or asexually. These findings may be of importance not only for basic evolutionary theory but also for other fields using the concept of genetic drift
Claude de Sainliens, un huguenot bourbonnais au temps de Shakespeare : un résumé très succinct, quelques ajouts et des pistes de recherche
Il n’y avait que très peu de travaux à caractère historique sur Claude de Sainliens avant la publication de ma biographie intitulée Claude de Sainliens : un huguenot bourbonnais au temps de Shakespeare (Paris, Orizons, 2012, 512 pages). Sainliens, qui était originaire du Bourbonnais, région située au centre de la France, naquit en 1564 ou 1565. C’était de loin le plus célèbre professeur de français huguenot dans l’Angleterre élisabéthaine où il trouva refuge en 1564 ou 1565. Il écrivit des grammaires, des dictionnaires, et surtout des manuels scolaires qui constituent pour les historiens des sources primaires du plus grand intérêt parce qu’elles contiennent une multitude d’éléments sur la vie quotidienne au XVIe siècle (nourriture, vêtements, jeux, relations sociales…). Quoiqu’un peu hédoniste et, de son propre aveu, grand amateur de vin, Sainliens était un puritain convaincu qui écrivit un traité contre la danse, et qui mit en garde ses lecteurs contre certaines pratiques jugées démoniaques comme le théâtre. Il se livra même à des activités d’espionnage en Europe continentale de mars 1587 à environ 1593. Shakespeare, qui le détestait, se moqua de lui dans quatre de ses pièces, surtout dans Peines d’amour perdues.There had been very little historical research on Claude de Sainliens until I published a biography entitled Claude de Sainliens: un huguenot bourbonnais au temps de Shakespeare (Paris, Orizons, 2012, 512 pages). Sainliens, who was originally from Bourbonnais, in central France, was born in 1534 or 1535. He was by far the most famous Huguenot teacher of French in Elizabethan England, where he found refuge in 1564 or 1565. He wrote grammars, dictionaries, and above all textbooks, which are extremely interesting sources for historians because they contain a wealth of details on daily life in the sixteenth century (food, clothes, games, social relations…). Though a self-confessed amateur of wine and a bit of a hedonist, Sainliens was a staunch puritan who wrote a treatise against dancing and warned his readers against such demonic activities as theatre-going. He was even a spy in continental Europe from March 1597 to about 1593. He was hated by Shakespeare who mocked him in four of his plays, most especially in Love’s Labour’s Lost
- …