Oscillator tunneling dynamics in the Rabi model

The familiar Rabi model, comprising a two-level system coupled to a quantum harmonic oscillator, continues to produce rich and surprising physics when the coupling strength becomes comparable to the individual subsystem frequencies. We construct approximate solutions for the regime in which the oscillator frequency is small compared to that of the two-level system and the coupling strength matches or exceeds the oscillator frequency. Relating our fully quantum calculation to a previous semi-classical approximation, we find that the dynamics of the oscillator can be considered to a good approximation as that of a particle tunneling in a classical double-well potential, despite the fundamentally entangled nature of the joint system. We assess the prospects for observation of oscillator tunneling in the context of nano- or micro-mechanical experiments and find that it should be possible if suitably high coupling strengths can be engineered.Comment: 25 pages, 5 figures, preprint forma

La importancia de los intercambios internacionales de recursos fitogenéticos para la mejora de los cultivos en Guatemala

Una de las principales consideraciones para la creación del Tratado Internacional sobre los Recursos Fitogenéticos para la Alimentación y la Agricultura y de su Sistema Multilateral para el acceso y la distribución de beneficios es el reconocimiento de la interdependencia de todos los países sobre los recursos genéticos de los cultivos y forrajes más importantes para la seguridad alimentaria global. Para apoyar la implementación de un sistema global de acceso e intercambio de recursos fitogenéticos, contribuyendo al desarrollo agrícola y la adaptación al cambio climático de los países, es necesario apreciar los beneficios de los intercambios históricos de germoplasma y reconocer que es urgente que un sistema de intercambio facilitado siga en pie y se expanda en el futuro. Tomando el caso de Guatemala, y del maíz y frijoles como cultivos principales, el artículo describe la dinámica de los recursos genéticos de estos dos cultivos, tanto dentro como fuera del país, en el pasado y mirando hacia el futuro. Se ilustra así el grado en que Guatemala depende de germoplasma de otros países para su seguridad alimentaria, y cómo, de manera complementaria, otros países dependen de germoplasma procedente de Guatemala. Se espera que la información presentada aquí estimule y facilite la implementación del Tratado Internacional y del Sistema Multilateral en el país

The importance of international exchanges of plant genetic resources for national crop improvement in Guatemala

One of the main considerations underlying the establishment of the International Treaty on Plant Genetic Resources for Food and Agriculture and its Multilateral System of Access and Benefit Sharing is the recognition of countries’ high interdependence on the genetic resources of the crops and forages which they depend upon for their food security. A continued appreciation of how countries have benefited from facilitated exchange of germplasm in the past and are likely to continue doing so in the future is needed, in order to move forward the implementation of the Multilateral System and creating a truly global pool of genetic resources for countries’ agricultural development and adaptation to climate change. Using Guatemala as a case and maize and beans as key crops, the paper presents a picture of the dynamics of their genetic resources, both inside and outside of the country, over past years and into the future. It illustrates the extent to which Guatemala is dependent upon germplasm from other countries for its food security, and how, in a complementary manner, other countries rely upon germplasm from Guatemala. It is hoped that the information presented here may encourage and facilitate the implementation of the International Treaty and its Multilateral System in the country

Effects of random localizing events on matter waves: formalism and examples

A formalism is introduced to describe a number of physical processes that may break down the coherence of a matter wave over a characteristic length scale l. In a second-quantized description, an appropriate master equation for a set of bosonic "modes" (such as atoms in a lattice, in a tight-binding approximation) is derived. Two kinds of "localizing processes" are discussed in some detail and shown to lead to master equations of this general form: spontaneous emission (more precisely, light scattering), and modulation by external random potentials. Some of the dynamical consequences of these processes are considered: in particular, it is shown that they generically lead to a damping of the motion of the matter-wave currents, and may also cause a "flattening" of the density distribution of a trapped condensate at rest.Comment: v3; a few corrections, especially in Sections IV and

Understanding the functional impact of alternative splicing in human cancer through Proteomics Informed by Transcriptomics

Recent advances in the fields of next generation sequencing and mass spec- trometry have enabled additional depth in sequencing, allowing further de- velopments for the fields of transcriptomics and proteomics. Additionally, software analyses for these data and computing power of machines have also improved over the past years. Yet, even though transcriptomics and proteomics are by essence deeply connected through the central dogma of biology, software pipelines capable of analysing both these data sources to- gether to extract additional biological insights are limited in terms of analysis capabilities and scope of application. This thesis describes the development of PITsuite, a software suite for in- tegrated analysis and visualisation of transcriptomics and proteomics data. Unlike previous software built for integration of transcriptomics and pro- teomics data, PITsuite supports a wide range of experimental designs, includ- ing quantitative protocols and multi-sample experiments. PITsuite comprises two main components: a customisable analysis pipeline, and a graphical user interface for browsing and visualising results. The efficacy of PITsuite was evaluated by application to several datasets from different studies. Notably, PITsuite was applied to transcriptomics and proteomics data from prostate cancer cells, as well as publicly available cancer data from TCGA (Tomczak et al., 2015), in order to understand the role of HNRNPA2B1 in prostate cancer, which findings are available in (Foster et al., 2022). This project led to a new software suite which provides the first software pipeline to integrate quantitative transcrip- tomics, proteomics and public data from the raw files up to visualisation of the results through a bespoke graphical user interface

Notas sobre el género Lepiota (Pers.: Fr.) Gray (Agaricales, Basidiomycotina) en el sudeste español

Se aportan datos corológicos de los 31 txones pertenecientes al género Lepiota (Pers.: Fr.) Gray ss. Kühner (1980) encontrados en el S.E. de la península ibérica. Se propone una nueva combinación: Lepiota subsquarrosa (Locq.) Gea et Honrubia.Notes on the genus Lepiota (Pers.: Fr.) Gray (Agaricales, Basidiomycotina) in South-Fast Spain. Thirty-one taxa of the genus Lepiota (Pers.: Fr.) Gray, sensu Kühner (1980) are recorded. Lepiota subsquarrosa (Locq.) Gea et Honrubia nov. comb. is proposed

Notas sobre el género Lepiota (Pers.: Fr.) Gray (Agaricales, Basidiomycotina) en el sudeste español

Se aportan datos corológicos de los 31 txones pertenecientes al género Lepiota (Pers.: Fr.) Gray ss. Kühner (1980) encontrados en el S.E. de la península ibérica. Se propone una nueva combinación: Lepiota subsquarrosa (Locq.) Gea et Honrubia.Notes on the genus Lepiota (Pers.: Fr.) Gray (Agaricales, Basidiomycotina) in South-Fast Spain. Thirty-one taxa of the genus Lepiota (Pers.: Fr.) Gray, sensu Kühner (1980) are recorded. Lepiota subsquarrosa (Locq.) Gea et Honrubia nov. comb. is proposed

Constraints for quantum logic arising from conservation laws and field fluctuations

We explore the connections between the constraints on the precision of quantum logical operations that arise from a conservation law, and those arising from quantum field fluctuations. We show that the conservation-law based constraints apply in a number of situations of experimental interest, such as Raman excitations, and atoms in free space interacting with the multimode vacuum. We also show that for these systems, and for states with a sufficiently large photon number, the conservation-law based constraint represents an ultimate limit closely related to the fluctuations in the quantum field phase.Comment: To appear in J. Opt. B: Quantum Semiclass. Opt., special issue on quantum contro

Construction of a scale to determinate the usefulness of Blogs in higher education

La incorporación de las herramientas digitales a la educación superior es incuestionable. En el caso de los blogs, estos son empleados de manera más latente, dada su facilidad de creación y empleo, y la no necesidad de poseer conocimientos informáticos para su creación. No obstante, nos cuestionamos si realmente son útiles para el desarrollo del currículo de los actuales estudios universitarios . Para determinar esto se ha procedido a construir una escala de valoración de la utilidad de los blogs en la educación superior. Para poder emplear la misma se ha procedido a realizar un estudio de la validez de la misma a través de la administración del mismo a una muestra de maestros de Educación Primaria en formación de la Universidad de Córdoba (N=162). El principal resultado alcanzado referente a la validez del instrumento señala que el análisis factorial exploratorio realizado a través de matrices po licóricas a nivel de ítem refleja tres factores que miden las tres dimensiones abordadas. La principal conclusión a la que se ha podido llegar es que el conocimiento en la elaboración de los blogs se relaciona estadísticamente con el desarrollo del currícu lo, el desarrollo comunicativo presente en cualquier acto de aprendizaje, y el desarrollo informacional digital

Dynamics of a two-level system strongly coupled to a high-frequency quantum oscillator

Recent experiments on quantum behavior in microfabricated solid-state systems suggest tantalizing connections to quantum optics. Several of these experiments address the prototypical problem of cavity quantum electrodynamics: a two-level system coupled to a quantum harmonic oscillator. Such devices may allow the exploration of parameter regimes outside the near-resonance and weak-coupling assumptions of the ubiquitous rotating-wave approximation (RWA), necessitating other theoretical approaches. One such approach is an adiabatic approximation in the limit that the oscillator frequency is much larger than the characteristic frequency of the two-level system. A derivation of the approximation is presented and the time evolution of the two-level-system occupation probability is calculated using both thermal- and coherent-state initial conditions for the oscillator. Closed-form evaluation of the time evolution in the weak-coupling limit provides insight into the differences between the thermal- and coherent-state models. Finally, potential experimental observations in solid-state systems, particularly the Cooper-pair box--nanomechanical resonator system, are discussed and found to be promising.Comment: 16 pages, 11 figures; revised abstract; some text revisions; added two figures and combined others; added references. Submitted to Phys. Rev.