Interrelations Between the Neutron's Magnetic Interactions and the Magnetic Aharonov-Bohm Effect

It is proved that the phase shift of a polarized neutron interacting with a spatially uniform time-dependent magnetic field, demonstrates the same physical principles as the magnetic Aharonov-Bohm effect. The crucial role of inert objects is explained, thereby proving the quantum mechanical nature of the effect. It is also proved that the nonsimply connectedness of the field-free region is not a profound property of the system and that it cannot be regarded as a sufficient condition for a nonzero phase shift.Comment: 18 pages, 1 postscript figure, Late

Correspondences and Quantum Description of Aharonov-Bohm and Aharonov-Casher Effects

We establish systematic consolidation of the Aharonov-Bohm and Aharonov-Casher effects including their scalar counterparts. Their formal correspondences in acquiring topological phases are revealed on the basis of the gauge symmetry in non-simply connected spaces and the adiabatic condition for the state of magnetic dipoles. In addition, investigation of basic two-body interactions between an electric charge and a magnetic dipole clarifies their appropriate relative motions and discloses physical interrelations between the effects. Based on the two-body interaction, we also construct an exact microscopic description of the Aharonov-Bohm effect, where all the elements are treated on equal footing, i.e., magnetic dipoles are described quantum-mechanically and electromagnetic fields are quantized. This microscopic analysis not only confirms the conventional (semiclassical) results and the topological nature but also allows one to explore the fluctuation effects due to the precession of the magnetic dipoles with the adiabatic condition relaxed

Megascopic Quantum Phenomena. A Critical Study of Physical Interpretations

A megascopic revalidation is offered providing responses and resolutions of current inconsistencies and existing contradictions in present-day quantum theory. As the core of this study we present an independent proof of the Goldstone theorem for a quantum field formulation of molecules and solids. Along with phonons two types of new quasiparticles appear: rotons and translons. In full analogy with Lorentz covariance, combining space and time coordinates, a new covariance is necessary, binding together the internal and external degrees of freedom, without explicitly separating the centre-of-mass, which normally applies in both classical and quantum formulations. The generally accepted view regarding the lack of a simple correspondence between the Goldstone modes and broken symmetries, has significant consequences: an ambiguous BCS theory as well as a subsequent Higgs mechanism. The application of the archetype of the classical spontaneous symmetry breaking, i.e. the Mexican hat, as compared to standard quantum relations, i.e. the Jahn-Teller effect, superconductivity or the Higgs mechanism, becomes a disparity. In short, symmetry broken states have a microscopic causal origin, but transitions between them have a teleological component. The different treatments of the problem of the centre of gravity in quantum mechanics and in field theories imply a second type of Bohr complementarity on the many-body level opening the door for megascopic representations of all basic microscopic quantum axioms with further readings for teleonomic megascopic quantum phenomena, which have no microscopic rationale: isomeric transitions, Jahn-Teller effect, chemical reactions, Einstein-de Haas effect, superconductivity-superfluidity, and brittle fracture.Comment: 117 pages, 17 sections, final revised version from 20 May 2019 but uploaded after the DOI was know

Déterminants de migrations des savants et des ingénieurs

Le pouvoir d'attraction des États-Unis sur les professionnels et les scientifiques du monde entier a été maintes fois signalé comme central dans la répartition internationale des compétences. À partir des données de deux enquêtes effectuées en 1967-1968 auprès de professionnels, de scientifiques et de techniciens canadiens, l'auteur propose une évaluation de l'importance de divers facteurs affectant l'émigration des professionnels canadiens vers les États-Unis. Il constate que l'enseignement aux États-Unis est le plus important facteur de la décision de chercher un emploi à plein temps aux États-Unis et que les titulaires des grades les plus élevés sont les plus susceptibles d'émigrer. Les Canadiens français sont moins susceptibles d'émigrer que les autres, de même que ceux qui ne sont pas nés en Amérique du Nord. D'autre part, la probabilité de retour au Canada est inversement proportionnelle à la durée de l'emploi aux États-Unis et, de même que ce sont les étudiants au niveau du doctorat qui sont le plus portés à émigrer, ce sont eux aussi qui sont le moins susceptibles de rentrer au pays.The pull of the United States on professionals and scientists has often been considered as crucial in the distribution of talent throughout the world. Using the results of two surveys conducted in 1967-1968 among Canadian professionals, scientists and technicians, the author proposes to evaluate the relative importance of the different elements affecting the emigration of Canadian professionals to the United States. He finds that having studied in the United States is the most important factor in the decision to look for full time employment there and that persons having studied at the higher levels are the most likely to emigrate. French Canadians and persons not born in North America are less likely to emigrate than others. Moreover, the chances of returning to Canada are inversely proportional to the length of employment in the United States, and whereas students at the doctorate level are the most likely to emigrate, they are also those who are the least likely to come back to the country.El poder de atracción de los Estados Unidos sobre los profesionales y los científicos de todo el mundo ha sido mencionada a menudo como un factor central en la repartición internacional de las competencias. A partir de los datos de dos encuestas realizadas en 1967-1968 sobre profesionales, científicos y técnicos canadienses, el autor propone una evaluación de la importancia de diversos factores que inciden sobre la emigración de los profesionales canadienses a los Estados Unidos. Constata que la enseñanza en los Estados Unidos constituye el factor más importante en la decisión de buscar un empleo a tiempo completo en este país y que los titulares de los grados más elevados son los más susceptibles de emigrar. Los Canadienses franceses así como los nacidos fuera de América del Norte son menos susceptibles de emigrar que los demás. Por otra parte, la probabilidad de retomo al Canadá es inversamente proporcional a la duración del empleo en los Estados Unidos y, así como los estudiantes de doctorado son los más inclinados a emigrar, son también dichos estudiantes los menos susceptibles de volver al país

Déterminants de migrations des savants et des ingénieurs

Le pouvoir d'attraction des États-Unis sur les professionnels et les scientifiques du monde entier a été maintes fois signalé comme central dans la répartition internationale des compétences. À partir des données de deux enquêtes effectuées en 1967-1968 auprès de professionnels, de scientifiques et de techniciens canadiens, l'auteur propose une évaluation de l'importance de divers facteurs affectant l'émigration des professionnels canadiens vers les États-Unis. Il constate que l'enseignement aux États-Unis est le plus important facteur de la décision de chercher un emploi à plein temps aux États-Unis et que les titulaires des grades les plus élevés sont les plus susceptibles d'émigrer. Les Canadiens français sont moins susceptibles d'émigrer que les autres, de même que ceux qui ne sont pas nés en Amérique du Nord. D'autre part, la probabilité de retour au Canada est inversement proportionnelle à la durée de l'emploi aux États-Unis et, de même que ce sont les étudiants au niveau du doctorat qui sont le plus portés à émigrer, ce sont eux aussi qui sont le moins susceptibles de rentrer au pays.</jats:p

Lower button‐cortex distance and lower revision rates with adjustable‐loop compared to fixed‐loop cortical suspension devices for anterior cruciate ligament reconstruction

Abstract Purpose To compare button position following femoral fixation of an anterior cruciate ligament (ACL) graft using fixed‐loop cortical suspension device vs. an adjustable‐loop device. Subsequently, to assess the association of button position‐related factors and revision ACL reconstruction. Methods This was a retrospective cohort study of consecutive patients undergoing ACL reconstruction using fixed‐loop (Endobutton CL) and adjustable‐loop cortical suspension device (Ultrabutton) for femoral fixation in a single institution between 2009 and 2022. Demographic and operative characteristics were recorded. To assess soft tissue interposition the distance between the button and the lateral femoral condyle (LFC) was measured on X‐rays made on the first post‐operative day. Other measurements included button angle, relative position (anterior/middle/posterior), and button migration (assessed using most recent X‐rays). Results Overall, 244 patients were included in the study. 59% of patients in the fixed‐loop group and 41% in the adjustable‐loop group. Hamstrings autograft was utilised most commonly (91%), while the rest of the procedures included allografts. A significantly shorter button distance from the LFC was noted in the post‐operative Antero‐posterior (AP) X‐ray of the adjustable‐loop button, 0.44 ± 0.52 mm versus 0.72 ± 0.84 mm, respectively (p = 0.002). Revision rates were significantly lower in the adjustable‐loop group (4%) versus the fixed‐loop group (12%, p = 0.035). No statistically significant direct association was found between button distance from the LFC and revision ACL reconstruction. Conclusions Adjustable‐loop cortical suspension devices for femoral fixation of an ACL reconstruction were associated with lower revision rates and a lower button‐LFC distance when compared to fixed‐loop devices. Level of Evidence Level III, retrospective comparative cohort study