Reservoir engineering with arbitrary temperatures for spin systems and quantum thermal machine with maximum efficiency

Abstract Reservoir engineering is an important tool for quantum information science and quantum thermodynamics since it allows for preparing and/or protecting special quantum states of single or multipartite systems or to investigate fundamental questions of the thermodynamics as quantum thermal machines and their efficiencies. Here we employ this technique to engineer reservoirs with arbitrary (effective) negative and positive temperatures for a single spin system. To this end, we firstly engineer an appropriate interaction between a qubit system, a carbon nuclear spin, to a fermionic reservoir, in our case a large number of hydrogen nuclear spins that acts as the spins bath. This carbon-hydrogen structure is present in a polycrystalline adamantane, which was used in our experimental setup. The required interaction engineering is achieved by applying a specific sequence of radio-frequency pulses using Nuclear Magnetic Resonance (NMR), while the temperature of the bath can be controlled by appropriate preparation of the initial hydrogen nuclear spin state, being the predicted results in very good agreement with the experimental data. As an application we implemented a single qubit quantum thermal machine which operates at a single reservoir at effective negative temperature whose efficiency is always 100%, independent of the unitary transformation performed on the qubit system, as long as it changes the qubit state.Comment: 7 pages, 6 figure

Exact Solution of an Evolutionary Model without Ageing

We introduce an age-structured asexual population model containing all the relevant features of evolutionary ageing theories. Beneficial as well as deleterious mutations, heredity and arbitrary fecundity are present and managed by natural selection. An exact solution without ageing is found. We show that fertility is associated with generalized forms of the Fibonacci sequence, while mutations and natural selection are merged into an integral equation which is solved by Fourier series. Average survival probabilities and Malthusian growth exponents are calculated indicating that the system may exhibit mutational meltdown. The relevance of the model in the context of fissile reproduction groups as many protozoa and coelenterates is discussed.Comment: LaTeX file, 15 pages, 2 ps figures, to appear in Phys. Rev.

Understanding Events by Eye and Ear: Agent and Verb Drive Non-anticipatory Eye Movements in Dynamic Scenes

As Macnamara (1978) once asked, how can we talk about what we see? We report on a study manipulating realistic dynamic scenes and sentences aiming to understand the interaction between linguistic and visual representations in real-world situations. Specifically, we monitored participants’ eye movements as they watched video clips of everyday scenes while listening to sentences describing these scenes. We manipulated two main variables. The first was the semantic class of the verb in the sentence and the second was the action/motion of the agent in the unfolding event. The sentences employed two verb classes–causatives (e.g., break) and perception/psychological (e.g., notice)–which impose different constraints on the nouns that serve as their grammatical complements. The scenes depicted events in which agents either moved toward a target object (always the referent of the verb-complement noun), away from it, or remained neutral performing a given activity (such as cooking). Scenes and sentences were synchronized such that the verb onset corresponded to the first video frame of the agent motion toward or away from the object. Results show effects of agent motion but weak verb-semantic restrictions: causatives draw more attention to potential referents of their grammatical complements than perception verbs only when the agent moves toward the target object. Crucially, we found no anticipatory verb-driven eye movements toward the target object, contrary to studies using non-naturalistic and static scenes. We propose a model in which linguistic and visual computations in real-world situations occur largely independent of each other during the early moments of perceptual input, but rapidly interact at a central, conceptual system using a common, propositional code. Implications for language use in real world contexts are discussed

Measured and modelled cloud condensation nuclei (CCN) concentration in São Paulo, Brazil: the importance of aerosol size-resolved chemical composition on CCN concentration prediction

Measurements of cloud condensation nuclei\ud (CCN), aerosol size distribution and non-refractory chemical\ud composition were performed from 16 to 31 October 2012\ud in the São Paulo Metropolitan Area (SPMA), Brazil. CCN\ud measurements were performed at 0.23, 0.45, 0.68, 0.90 and\ud 1.13% water supersaturation and were subsequently compared\ud with the Köhler theory, considering the chemical composition.\ud Real-time chemical composition has been obtained\ud by deploying, for the first time in the SPMA, an aerosol\ud chemical ionization monitor (ACSM). CCN closure analyses\ud were performed considering internal mixtures.\ud Average aerosol composition during the studied period\ud yielded (arithmetic mean ±standard deviation) 4.81±3.05,\ud 3.26±2.10, 0.30±0.27, 0.52±0.32, 0.37±0.21 and\ud 0.04±0.04 μgm−3 for organics, BC, NH4, SO4, NO3\ud and Cl, respectively. Particle number concentration was\ud 12 813±5350 cm−3, with a dominant nucleation mode.\ud CCN concentrations were on average 1090±328 and\ud 3570±1695 cm−3 at SS = 0.23% and SS = 1.13 %, respectively.\ud Results show an increase in aerosol hygroscopicity in the\ud afternoon as a result of aerosol photochemical processing,\ud leading to an enhancement of both organic and inorganic secondary\ud aerosols in the atmosphere, as well as an increase in\ud aerosol average diameter.\ud Considering the bulk composition alone, observed CCN\ud concentrations were substantially overpredicted when compared\ud with the Köhler theory (44.1±47.9% at 0.23% supersaturation and 91.4±40.3% at 1.13% supersaturation).\ud Overall, the impact of composition on the calculated CCN\ud concentration (NCCN) decreases with decreasing supersaturation,\ud partially because using bulk composition introduces\ud less bias for large diameters and lower critical supersaturations,\ud defined as the supersaturation at which the cloud\ud droplet activation will take place. Results suggest that the\ud consideration of only inorganic fraction improves the calculated\ud NCCN.\ud Introducing a size-dependent chemical composition based\ud on filter measurements from previous campaigns has considerably\ud improved simulated values for NCCN (average overprediction\ud error 14.8±38.6% at 0.23% supersaturation and\ud 3.6±21.6% at 1.13% supersaturation). This study provides\ud the first insight on aerosol real-time composition and hygroscopicity\ud at a site strongly impacted by emissions of a unique\ud vehicular fleet due to the extensive biofuel usageFAPES

Antioxidant activity and acute toxicity of Neoglaziovia variegata (Bromeliaceae)

Antioxidant activities of Neoglaziovia variegata were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching and was compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The total phenolics content of the extracts was determined by the Folin-Ciocalteu method. Total flavonoid was also determined. The most significant total phenolic content was of 543.50 ± 9.38 mg of gallic acid equivalent/g for ethyl acetate extract (AcOEt), which presented the best antioxidant activity (IC50 5.08 ± 0.20 μg/ml) for DPPH scavenging. The acute toxicity of Nv-EtOH was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in mice. No mortality and no toxicity signs were observed, indicating low toxicity of the extract. Blood was removed after 14 days for laboratory analysis of hematological and biochemical parameters. Alterations of aspartate aminotransferase (AST) and creatinine were observed. The data obtained showed that the doses induced microscopic alterations in the liver and kidney. In conclusion, the Nv-EtOH can be considered of low toxicity.Keywords: Antioxidant activity, acute toxicity, Neoglaziovia variegata, Bromeliacea

Otimização da extração de ácidos nucleicos de material de punção aspirativa por agulha fina de tiroide obtido de lâminas coradas, tecidos fixados em formalina e emblocados em parafina e amostras de sangue estocadas por longo período

OBJECTIVE: Adequate isolation of nucleic acids from peripheral blood, fine-needle aspiration cells in stained slides, and fresh and formalin-fixed/paraffin-embedded tissues is crucial to ensure the success of molecular endocrinology techniques, especially when samples are stored for long periods, or when no other samples can be collected from patients who are lost to follow-up. Here, we evaluate several procedures to improve current methodologies for DNA (salting-out) and RNA isolation. MATERIALS AND METHODS: We used proteinase K treatment, heat shock, and other adaptations to increase the amount and quality of the material retrieved from the samples. RESULTS: We successfully isolated DNA and RNA from the samples described above, and this material was suitable for PCR, methylation profiling, real-time PCR and DNA sequencing. CONCLUSION: The techniques herein applied to isolate nucleic acids allowed further reliable molecular analyses. Arq Bras Endocrinol Metab. 2012;56(9):618-26OBJETIVO: O isolamento adequado de ácidos nucleicos a partir de sangue periférico, lâmina corada de punção aspirativa por agulha fina, tecido fixado em formalina e emblocado em parafina e tecido fresco é fundamental para assegurar o sucesso de técnicas aplicadas em endocrinologia molecular, principalmente quando lidamos com amostras estocadas por longos períodos ou quando há impossibilidade de nova coleta de amostra de pacientes que perderam o seguimento. Neste trabalho, objetivamos otimizar as metodologias clássicas para a extração de DNA (salting-out) e RNA. MATERIAIS E MÉTODOS: Utilizamos proteinase K, choque térmico, dentre outras modificações, com o objetivo de aumentar a quantidade e a qualidade do material recuperado a partir das amostras descritas acima. RESULTADOS: Isolamos com sucesso DNA e RNA de tais amostras e o material obtido foi adequado para a realização de PCR, perfil de metilação, PCR em tempo real e sequenciamento de DNA. CONCLUSÃO: As técnicas aplicadas neste estudo para isolar ácidos nucleicos permitiram a realização posterior de análises moleculares consistentes e confiáveis. Arq Bras Endocrinol Metab. 2012;56(9):618-26Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaFaculdade de Medicina do ABC Department of Morphology and PhysiologyUNIFESP, EPMSciEL