Efficient evaluation of decoherence rates in complex Josephson circuits

A complete analysis of the decoherence properties of a Josephson junction qubit is presented. The qubit is of the flux type and consists of two large loops forming a gradiometer and one small loop, and three Josephson junctions. The contributions to relaxation (T_1) and dephasing (T_\phi) arising from two different control circuits, one coupled to the small loop and one coupled to a large loop, is computed. We use a complete, quantitative description of the inductances and capacitances of the circuit. Including two stray capacitances makes the quantum mechanical modeling of the system five dimensional. We develop a general Born-Oppenheimer approximation to reduce the effective dimensionality in the calculation to one. We explore T_1 and T_\phi along an optimal line in the space of applied fluxes; along this "S line" we see significant and rapidly varying contributions to the decoherence parameters, primarily from the circuit coupling to the large loop.Comment: 16 pages, 20 figures; v2: minor revisio

Sports sponsorship and the impact on a brand's purchasing intention and recommendation: Red Bull, more than wings

Sponsorship has proven to be a fast-flourishing marketing tool. Its main essence is, in the companies' perspective, to effectively promote their products and services. Therefore, over the years, companies have begun to behold and consider this tool as a massive gateway for a successful strategical long-term plan. Previous sponsorship studies, have instigated to examine its concept on multiple situations and the implications they entail, but often lack new effective measures and approaches. Hence, the purpose of this investigation is to better understand and scrutinize the effects of Sports Sponsorship - its Awareness, Perceived Quality and Image - on Brand Equity variables, in particular, on Brand Image, Brand Awareness, Brand Loyalty and Perceived Brand Quality. Consequently, with that in mind, there is an examination of the effect/influence on the consumer's Brand Purchasing Intention and Brand Recommendation. Moreover, Red Bull, is used as a main reference. The energy drinks' company was placed on a Sports Sponsorship context, with 3 main sports highlighted (Football/Soccer, Air Racing and Formula 1). The respondents (from a diverse age range), were asked several questions considering Sponsorship and Brand Equity's variables and, their a-posteriori Brand Purchasing Intention and Recommendation - always heeding the Brand´s Sports Sponsorship they consider to be the most important. The results gathered by the following research propose that the presence of a Sports Sponsorship initiative brings no direct influence on a Brand's Purchasing Intention and Recommendation. In addition, Perceived Brand Quality affects both final variables, whereas Brand Awareness impacts none.O Patrocínio tem-se revelado uma ferramenta de rápido crescimento, tendo como principal objetivo, do ponto de vista das empresas, a promoção eficaz dos seus produtos e serviços. Com o passar dos anos, as empresas começaram a reconhecer esta ferramenta como um portal sólido para o sucesso estratégico, no longo prazo. Estudos prévios sobre o Patrocínio têm exibido detalhadas análises, sob diversas situações, todavia, sem um fio condutor eficaz. Portanto, o objetivo desta investigação consiste num melhor escrutínio dos efeitos do Patrocínio no Desporto - a sua Consciência, Qualidade Percetível e Imagem - nas variáveis referentes ao Valor da Marca, mais exatamente, a Imagem da Marca, a Consciência da Marca, a Lealdade à Marca e a Qualidade Percetível da Marca. Consequentemente, é examinado o efeito na Intenção de Compra e Recomendação da Marca. Para além disso, Red Bull, é usada como referência principal de estudo. A empresa de bebidas energéticas foi colocada no contexto dos seus patrocínios desportivos, com realce a três (Futebol, "Air Racing" e Formula 1). Os inquiridos foram questionados relativamente às variáveis de Patrocínio e Valor da Marca, como também, à Intenção de Compra e Recomendação da Marca – considerando o Patrocínio de Desporto por eles considerado como o mais importante para a Marca. Os resultados recolhidos da investigação apontam para que as iniciativas de Patrocínio no Desporto não tenham uma influência direta na Intenção de Compra e Recomendação da Marca. Ademais, a Qualidade Percetível da Marca produz um efeito direto nas duas variáveis dependentes, ao invés da Consciência à Marca

Molecular Mechanisms of Memory Formation and Persistence in the Adult and Aged Brain

Memory formation relies on an orchestrated activation of cellular and molecular mechanisms that drive acquisition and consolidation of memories into a stable form. Research of the past decades has begun to elucidate how activation at the synapse promotes communication to the nucleus, where learning-induced gene expression takes place. This genomic response, that also includes post-transcriptional alterations in the newly-synthetized transcripts, is required for long-term memory formation. In in the first sections of this work, we uncovered a role for the Growth Arrest and DNA Damage γ (Gadd45γ) in memory formation and age-related cognitive decline. We showed that Gadd45γ mediates synapse-to-nucleus communication required for induction of activity-dependent gene expression and memory formation. We further identified that the expression of this protein is tightly regulated in hippocampal neurons. Decreasing or increasing Gadd45γ expression compromised activity-dependent gene expression and memory formation. We further discovered that during murine and human aging the hippocampal expression of this protein is dysregulated, suggesting that it may be involved in age-related cognitive decline. In the next section, we identified the alternative splicing program associated with spatial memory formation. We showed that the DNA methylation reader methyl-CpG-binding protein 2 (MeCP2) is required for the accurate induction of alternative splicing in baseline conditions and after learning. These findings place MeCP2 as a key regulator of adult brain function, particularly cognitive abilities. Lastly, we investigated molecular mechanisms underlying memory persistence. We showed that neuronal PAS domain protein 4 (Npas4) expression is induced several hours after persistent memory learning, but not when mice form short-lasting memories. This delayed expression is dependent on N-Methyl-D-aspartic acid (NMDA) receptor activation several hours after learning. Interestingly, artificially inducing Npas4 expression in a short-lasting memory protocol, further accelerated memory decay. These findings suggest that late Npas4 expression might be a mechanism associated with forgetting. Altogether, in this work we discovered new molecular mechanisms of memory formation and persistence in the adult and aged brain

Fault-Tolerant Computing With Biased-Noise Superconducting Qubits

We present a universal scheme of pulsed operations for the IBM oscillator-stabilized flux qubit comprising the CPHASE gate, single-qubit preparations and measurements. Based on numerical simulations, we argue that the error rates for these operations can be as low as about .5% and that noise is highly biased, with phase errors being stronger than all other types of errors by a factor of nearly 10^3. In contrast, the design of a CNOT gate for this system with an error rate of less than about 1.2% seems extremely challenging. We propose a special encoding which exploits the noise bias allowing us to implement a logical CNOT gate where phase errors and all other types of errors have nearly balanced rates of about .4%. Our results illustrate how the design of an encoding scheme can be adjusted and optimized according to the available physical operations and the particular noise characteristics of experimental devices.Comment: 15 pages, 7 figure

6th EUGEO Congress

info:eu-repo/semantics/draf

Seeking the causes of urban ruination: An empirical research in four Portuguese cities

Urban ruination is an understudied feature in the life of cities. This article discusses its causes. Based on the study of four shrinking Portuguese cities (Lisbon, Barreiro, Guimarães and Vizela), and using Multiple Linear Regression Analysis as the statistical method, the structure of relationships among ruins, economic change, demographic change, social geography and the characteristics of buildings are discussed. Although the study concludes that ruination is a highly contingent phenomenon, the results show that of all the structural fac- tors, demographic ageing and the obsolescence of buildings (poor housing conditions) are the key causes of ruination in the four cities under study. Links between ruination and socio-spatial processes have also been identified.info:eu-repo/semantics/publishedVersio