3,898 research outputs found
Classification of Dark States in Multi-level Dissipative Systems
Dark states are eigenstates or steady-states of a system that are decoupled
from the radiation. Their use, along with associated techniques such as
Stimulated Raman Adiabatic Passage, has extended from atomic physics where it
is an essential cooling mechanism, to more recent versions in condensed phase
where it can increase the coherence times of qubits. These states are often
discussed in the context of unitary evolution and found with elegant methods
exploiting symmetries, or via the Bruce-Shore transformation. However, the link
with dissipative systems is not always transparent, and distinctions between
classes of CPT are not always clear. We present a detailed overview of the
arguments to find stationary dark states in dissipative systems, and examine
their dependence on the Hamiltonian parameters, their multiplicity and purity.
We find a class of dark states that depends not only on the detunings of the
lasers but also on their relative intensities. We illustrate the criteria with
the more complex physical system of the hyperfine transitions of Rb and
show how a knowledge of the dark state manifold can inform the preparation of
pure states.Comment: additional example
Distorted food pyramid in kids programmes: A content analysis of television advertising watched in Switzerland
Background: In the light of increasing childhood obesity, the role of food advertisements relayed on television (TV) is of high interest. There is evidence of food commercials having an impact on children's food preferences, choices, consumption and obesity. We describe the product categories advertised during kids programmes, the type of food promoted and the characteristics of food commercials targeting children. Methods: A content analysis of the commercials aired during the kids programmes of six Swiss, one German and one Italian stations was conducted. The commercials were collected over a 6-month period in 2006. Results: Overall, 1365 h of kids programme were recorded and 11 613 advertisements were found: 3061 commercials (26.4%) for food, 2696 (23.3%) promoting toys, followed by those of media, cleaning products and cosmetics. Regarding the broadcast food advertisements, 55% were for fast food restaurants or candies. Conclusion: The results of the content analysis suggest that food advertising contributes to the obesity problem: every fourth advertisement is for food, half of them for products high in sugar and fat and hardly any for fruit or vegetables. Long-term exposure to this distortion of the pyramid of recommended food should be considered in the discussion of legal restrictions for food advertising targeting childre
Criação de um modelo para implementação de novas tecnologias da informação em prefeituras
Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de ProduçãoA pesquisa apresenta um modelo para implementação de Tecnologia da Informação (TI) em prefeituras que engloba bases de dados, sistemas de gestão, pregão eletrônico e planejamento estratégico da TI (PETI) e que permite uma futura gestão do conhecimento. O modelo proposto apresenta a seqüência de implementações que devem ser feitas e quais as dificuldades e soluções a elas relacionadas, visando a uma melhoria na administração pública dentro do ambiente de Governo Eletrônico. A importância de um planejamento que inclua todos os componentes dos Sistemas de Informação é fundamental neste enfoque, que trata de uma visão sistêmica desde as bases mais operacionais até chegar a um ambiente mais estratégico, que inclui Data Warehouse e Business Intelligence aplicados à Administração Pública, o que possibilita uma estrutura suficiente para assumir o desafio de realizar a gestão do conhecimento dentro de uma prefeitura. O Sistema de pregão eletrônico tem um caráter estratégico dentro deste modelo proposto e oferece não somente economia e velocidade nas transações, mas também transparência aos cidadãos. Este sistema tem destaque dentro de todo o processo porque permite a comprovação da economia nas compras púbicas, mostrando os benefícios financeiros mensuráveis que a TI pode oferecer, fato que aumenta a certeza do administrador sobre o retorno do investimento. Foi feito um estudo de caso na Prefeitura Municipal de Florianópolis, verificado com base na pesquisa qualitativa que incluiu a observação, entrevistas informais e comparações de resultados comprovados do sistema implantado. O estudo mostrou os impactos financeiros, tecnológicos, de prestação de contas, de integração e políticos da modernização administrativa, destacando que as maiores barreiras na implantação destes sistemas não são tecnológicas, mas sim culturais
Ein Beitrag zum Toxnetz-Explorer: Der Magen-Darm-Trakt
Die vorliegende Abschlussarbeit „Der Magen-Darm-Trakt: Ein Beitrag zum Toxnetz-Explorer“, wurde von Frau Dr. Simone Miriam Keller im Rahmen des Postgradualstudiums Toxikologie und Umweltschutz der Universität Leipzig angefertigt. In der eingereichten Arbeit werden allgemeine Strukturen des Magen-Darm-Trakts sowie die einzelnen Organe anatomisch beschrieben. Es werden die Funktionen und Aufgaben der Organe des Magen-Darm-Trakts bei der Absorption, Metabolisierung und Ausscheidung erläutert sowie die Metabolisierung von Fremdstoffen wie Arzneimittel und toxische Bestandteile von Nahrungsmitteln, am Beispiel des Mykotoxins Patulin, beschrieben. Die Arbeit dient als Grundlage zur Erstellung eines Toxnetz-Explorer Kapitels zum Thema Magen-Darm-Trakt
Incorporação de novas tecnologias de informação e comunicação na área empresarial :: um estudo de caso /
Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico
Metrological advantage at finite temperature for Gaussian phase estimation
In the context of phase estimation with Gaussian states, we introduce a
quantifiable definition of metrological advantage that takes into account
thermal noise in the preparation procedure. For a broad set of states,
\textit{isotropic non-pure Gaussian states}, we show that squeezing is not only
necessary, but sufficient, to achieve metrological advantage. We interpret our
results in the framework of resource theory, and discuss possible sources of
advantage other than squeezing. Our work is a step towards using phase
estimation with pure and mixed state to define and quantify nonclassicality.
This work is complementary with studies that defines nonclassicality using
quadrature displacement estimation.Comment: Changes to wording, figures replace
Focus on teachers: Approaches to promoting health and performance
Gesunde Lehrpersonen sind eine wichtige Voraussetzung für die Gesundheit und den Bildungserfolg der Schülerinnen und Schüler. Allerdings zeigen aktuelle Studien, dass viele Lehrpersonen aufgrund ihrer beruflichen Herausforderungen unter einem hohen Stressniveau leiden. Der vorliegende Beitrag untersucht, wie die Gesundheit von Lehrpersonen gestärkt werden kann. Auf der Ebene der Behörden werden die Rahmenbedingungen als Voraussetzung für die Lehrpersonengesundheit thematisiert. Darüber hinaus wird die Schule als Organisation in den Blick genommen, wobei das Führungsverhalten der Schulleitung sowie die Zusammenarbeit im Team beleuchtet werden. Auf der Ebene des Individuums liegt der Fokus auf dem Erleben von Stress und dem Umgang damit. Basierend auf diesen Erkenntnissen werden Implikationen für die Aus- und Weiterbildung von Lehrpersonen formuliert. (DIPF/Orig.)Teachers\u27 health is a crucial factor for both pupils\u27 health and educational success. Recent research shows, however, that many teachers experience increased levels of stress due to the challenges in their profession. This article discusses strategies for enhancing teachers\u27 health. It explores the role of administrative authorities in the establishment of frameworks that are conducive to teachers\u27 well-being. Furthermore, it examines the organizational aspects within schools, including school principals\u27 leadership behaviour and the dynamics of teamwork. On the level of the individual, the article highlights the importance of understanding stress and coping with it. Based on these findings, implications for teacher education and professional development are formulated. (DIPF/Orig.
- …