High-resolution spatial mapping of a superconducting NbN wire using single-electron detection

Superconducting NbN wires have recently received attention as detectors for visible and infrared photons. We present experiments in which we use a NbN wire for high-efficiency (40 %) detection of single electrons with keV energy. We use the beam of a scanning electron microscope as a focussed, stable, and calibrated electron source. Scanning the beam over the surface of the wire provides a map of the detection efficiency. This map shows features as small as 150 nm, revealing wire inhomogeneities. The intrinsic resolution of this mapping method, superior to optical methods, provides the basis of a characterization tool relevant for photon detectors.Comment: 2009 IEEE Toronto International Conference, Science and Technology for Humanity (TIC-STH

Fusion reactor design studies

This progress report will give a detailed breakdown of the work accomplished for ARIES-III during the contract period, November 1, 1990 to October 31, 1991. The areas of effort discussed are: Neutronics; First-Wall; Shield; Safety; Systems; Startup and Shutdown; Energy Conversion; Ripple Loss; and Fuel Resources

Avaliação do crescimento Cedrela odorata em plantio de enriquecimento realizado em clareiras de pós-exploração madeireira.

Avaliou-se o crescimento de Cedrela odorata L. em plantio de enriquecimento de clareiras ocasionadas pela exploração florestal em Almeirim, Pará. Em 2007 foram plantados 126 indivíduos de C. odorata em 8 clareiras. Nas clareiras, níveis de incidência de luz foram atribuídos aos indivíduos, sendo eles: 1,5 (baixa incidência de luz lateral na planta); 2 (luz lateral); 2,5 (luz direta e lateral); e, 3 (alta incidência de luz direta e lateral). Nessas condições, o crescimento dos indivíduos foi avaliado pelas medições sucessivas do diâmetro à altura do peito nos anos de 2012, 2017 e 2018, que permitiram calcular o incremento periódico anual em diâmetro (IPA) em a área basal. O IPA entre 2012 e 2018 foi de 0,2852 cm.ano-1, 0,4400 cm.ano-1, 0,4942 cm.ano-1 e 0,6178 cm.ano-1, para os níveis luminosos de 1,5, 2, 2,5 e 3, respectivamente. A área basal em 2012 foi de 0,02665 m².ha-1, em 2017 de 0,07724 m².ha-¹, e em 2018, 0,08892 m².ha-¹. C. odorata possuiu ótimo desempenho em áreas com alta incidência de luz, como as clareiras, e pode ser recomendada ao plantio de enriquecimento

Connections between Classical and Parametric Network Entropies

This paper explores relationships between classical and parametric measures of graph (or network) complexity. Classical measures are based on vertex decompositions induced by equivalence relations. Parametric measures, on the other hand, are constructed by using information functions to assign probabilities to the vertices. The inequalities established in this paper relating classical and parametric measures lay a foundation for systematic classification of entropy-based measures of graph complexity

Desempeño de Tachigali Glauca tul. bajo diferentes tratamientos en brechas en la Amazônia Oriental.

El desempeño de la especie comercial Tachigali glauca Tul. en el registro de las brechas en tres tratamientos diferentes se analizó en un experimento llevado a cabo en un bosque denso y ombrófilo cosechado en la Amazonía oriental. El estudio comparó durante 9 años, en 28 brechas, las tasas de mortalidad, el incremento periódico anual (IPA) en diámetros y la área basal en los siguientes tratamientos: (i) control (CT) sin intervenciones silvícolas sobre individuos naturalmente establecidos en la brecha; (ii) la conducción de la regeneración natural (RN), pero sometido a tratamientos silvícolas como la limpieza; (iii) la plantación de enriquecimiento (PL) de mudas y plántulas. Los tres tratamientos contaron inicialmente con 9; 11 y 8 brechas y 35; 17 y 129 individuos, respectivamente. Respecto a la tasa de mortalidad, CT presentó total de 1,1% año-1, RN 0,55% año-1 y PL 0,85% año-1. Sin embargo, para el IPA, CT mostró 0.268 cm año-1, RN 0.544 cm año-1 y PL 0.985 cm año-1. Y para el área basal, CT obtuvo 0,04 m²ha-1, RN 0,11 m²ha-1 y PL 1,78 m²ha-1. La principal conclusión es que T.glauca, cuando se somete al tratamiento de RN, presenta una buena respuesta creciente. Aunque su area basal fue menor, su tasa de mortalidad fue baja y PAI alto y en comparación con los otros tratamientos. Estos resultados ayudan a hacer de T.glauca una especie más atractiva para la industria maderera y las actividades de reforestación/restauración.Título em inglês: Performance of tachigali glauca tul. under diferrent treatmentes in eastern amazon gaps

Viral expression and molecular profiling in liver tissue versus microdissected hepatocytes in hepatitis B virus - associated hepatocellular carcinoma.

Background: The molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by studying multiple areas of the same liver from patients with HCC. Methods: We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes along with the intrahepatic expression of HBV. Gene expression profiling was performed on up to 17 WLT specimens obtained at various distances from the tumor center from individual livers of 11 patients with HCC and on selected LCM samples. HBV markers in liver and serum were determined by real-time polymerase chain reaction (PCR)and confocal immunofluorescence. Results: Analysis of 5 areas of the liver showed a sharp change in gene expression between the immediate perilesional area and tumor periphery that correlated with a significant decrease in the intrahepatic expression of HB surface antigen (HBsAg). The tumor was characterized by a large preponderance of down-regulated genes, mostly involved in the metabolism of lipids and fatty acids, glucose, amino acids and drugs, with down-regulation of pathways involved in the activation of PXR/RXR and PPARα/RXRα nuclear receptors, comprising PGC-1α and FOXO1, two key regulators critically involved not only in the metabolic functions of the liver but also in the life cycle of HBV, acting as essential transcription factors for viral gene expression. These findings were confirmed by gene expression of microdissected hepatocytes. Moreover, LCM of malignant hepatocytes also revealed up-regulation of unique genes associated with cancer and signaling Pathways, including two novel HCC-associated cancer testis antigen genes, NUF2 and TTK. Conclusions: Integrated gene expression profiling of whole liver tissue with that of microdissected hepatocytes demonstrated that HBV-associated HCC is characterized by a metabolism switch-off and by a significant reduction in HBsAg. LCM proved to be a critical tool to validate gene signatures associated with HCC and to identify genes that may play a role in hepatocarcinogenesis, opening new perspectives for the discovery of novel diagnostic markers and therapeutic targets

Integrative Network Biology: Graph Prototyping for Co-Expression Cancer Networks

Network-based analysis has been proven useful in biologically-oriented areas, e.g., to explore the dynamics and complexity of biological networks. Investigating a set of networks allows deriving general knowledge about the underlying topological and functional properties. The integrative analysis of networks typically combines networks from different studies that investigate the same or similar research questions. In order to perform an integrative analysis it is often necessary to compare the properties of matching edges across the data set. This identification of common edges is often burdensome and computational intensive. Here, we present an approach that is different from inferring a new network based on common features. Instead, we select one network as a graph prototype, which then represents a set of comparable network objects, as it has the least average distance to all other networks in the same set. We demonstrate the usefulness of the graph prototyping approach on a set of prostate cancer networks and a set of corresponding benign networks. We further show that the distances within the cancer group and the benign group are statistically different depending on the utilized distance measure

Photodetection of propagating quantum microwaves in circuit QED

We develop the theory of a metamaterial composed of an array of discrete quantum absorbers inside a one-dimensional waveguide that implements a high-efficiency microwave photon detector. A basic design consists of a few metastable superconducting nanocircuits spread inside and coupled to a one-dimensional waveguide in a circuit QED setup. The arrival of a {\it propagating} quantum microwave field induces an irreversible change in the population of the internal levels of the absorbers, due to a selective absorption of photon excitations. This design is studied using a formal but simple quantum field theory, which allows us to evaluate the single-photon absorption efficiency for one and many absorber setups. As an example, we consider a particular design that combines a coplanar coaxial waveguide with superconducting phase qubits, a natural but not exclusive playground for experimental implementations. This work and a possible experimental realization may stimulate the possible arrival of "all-optical" quantum information processing with propagating quantum microwaves, where a microwave photodetector could play a key role.Comment: 27 pages, submitted to Physica Scripta for Nobel Symposium on "Qubits for Quantum Information", 200

Quantum Computation by Communication

We present a new approach to scalable quantum computing--a ``qubus computer''--which realises qubit measurement and quantum gates through interacting qubits with a quantum communication bus mode. The qubits could be ``static'' matter qubits or ``flying'' optical qubits, but the scheme we focus on here is particularly suited to matter qubits. There is no requirement for direct interaction between the qubits. Universal two-qubit quantum gates may be effected by schemes which involve measurement of the bus mode, or by schemes where the bus disentangles automatically and no measurement is needed. In effect, the approach integrates together qubit degrees of freedom for computation with quantum continuous variables for communication and interaction.Comment: final published versio