The geometric properties of an expandable whirling-membrane solar-energy concentrator

Geometric properties of expandable whirling membrane solar energy concentrator used in conjunction with electrical conversion systems for spacecraft auxiliary power unit

Distribuição do carbono orgânico em Latossolo sob manejo da adubação fosfatada em plantio direto no Cerrado.

O objetivo deste trabalho foi avaliar a distribuição vertical e horizontal do carbono orgânico do solo (CO) sob cinco manejos da adubação fosfatada, no sistema plantio direto. O experimento foi instalado sob Latossolo Vermelho, cultivado durante oito anos com soja ou milho, com milheto como planta de cobertura na entressafra. As parcelas foram submetidas aos tratamentos: aplicação de superfosfato triplo a lanço e no sulco, fosfato natural reativo a lanço e no sulco, e ausência de adição de fertilizante fosfatado (testemunha). A adição anual dos adubos fosfatados, na dose de 80 kg ha‑1 de P2O5, foi realizada em solo inicialmente com baixo teor de fósforo disponível. Amostras foram coletadas perpendicularmente à linha de plantio, em sete pontos distanciados a 12,5 cm, e cinco camadas: 0?2,5, 2,5?5,0, 5,0?10, 10?20 e 20?30 cm. O conteúdo e a distribuição do CO são afetados pela adubação fosfatada, tanto vertical quanto horizontalmente, com os maiores conteúdos observados nos tratamentos com adubos fosfatados. Em comparação com a testemunha, o superfosfato triplo apresentou maior conteúdo de CO até a camada de 5,0?10 cm, e o fosfato natural reativo até 10?20 cm. A aplicação de fósforo em sulcos proporciona maior volume de solo com teores adequados de CO, em comparação à aplicação a lanço

The QUEST large area CCD camera

We have designed, constructed, and put into operation a very large area CCD camera that covers the field of view of the 1.2 m Samuel Oschin Schmidt Telescope at the Palomar Observatory. The camera consists of 112 CCDs arranged in a mosaic of four rows with 28 CCDs each. The CCDs are 600 x 2400 pixel Sarnoff thinned, back-illuminated devices with 13 µm x 13 µm pixels. The camera covers an area of 4.6° x 3.6° on the sky with an active area of 9.6 deg_2. This camera has been installed at the prime focus of the telescope and commissioned, and scientific-quality observations on the Palomar-QUEST Variability Sky Survey were started in 2003 September. The design considerations, construction features, and performance parameters of this camera are described in this paper

Time Domain Explorations With Digital Sky Surveys

One of the new frontiers of astronomical research is the exploration of time variability on the sky at different wavelengths and flux levels. We have carried out a pilot project using DPOSS data to study strong variables and transients, and are now extending it to the new Palomar-QUEST synoptic sky survey. We report on our early findings and outline the methodology to be implemented in preparation for a real-time transient detection pipeline. In addition to large numbers of known types of highly variable sources (e.g., SNe, CVs, OVV QSOs, etc.), we expect to find numerous transients whose nature may be established by a rapid follow-up. Whereas we will make all detected variables publicly available through the web, we anticipate that email alerts would be issued in the real time for a subset of events deemed to be the most interesting. This real-time process entails many challenges, in an effort to maintain a high completeness while keeping the contamination low. We will utilize distributed Grid services developed by the GRIST project, and implement a variety of advanced statistical and machine learning techniques.Comment: 5 pages, 2 postscript figures, uses adassconf.sty. To be published in: "ADASS XIV (2004)", Eds. Patrick Shopbell, Matthew Britton and Rick Ebert, ASP Conference Serie

Effective Hamiltonian Theory and Its Applications in Quantum Information

This paper presents a useful compact formula for deriving an effective Hamiltonian describing the time-averaged dynamics of detuned quantum systems. The formalism also works for ensemble-averaged dynamics of stochastic systems. To illustrate the technique we give examples involving Raman processes, Bloch-Siegert shifts and Quantum Logic Gates.Comment: 5 pages, 3 figures, to be published in Canadian Journal of Physic

Organic carbon distribution in an Oxisol under phosphate fertilizer management and no‑tillage in the Cerrado

The objective of this work was to evaluate the vertical and horizontal distribution of soil organic carbon (SOC) under five managements of phosphate fertilizer in a no‑tillage system. The experiment was established on a Rhodic Haplustox, cultivated with soybean or corn for eight years, with millet as cover crop during the off-season. Plots were subjected to the following treatments: triple superphosphate in the sowing furrow or on surface, reactive natural phosphate on the sowing furrow or on surface, and without the addition of phosphate fertilizer (control). Phosphate fertilizer was applied annually at a dosage of 80 kg ha‑1 of P2O5 on soil initially with a low phosphorous content. Samples were collected perpendicularly to the sowing line in seven sites distanced at 12.5 cm, and in five layers: 0–2.5, 2.5–5.0, 5.0–10, 10–20, and 20–30 cm. The content and the distribution of SOC are vertically and horizontally affected by phosphate fertilization, with highercontents in treatments with phosphate fertilizers. Compared to the control treatment, triple superphosphateshowed higher SOC concentrations until the 5.0–10‑cm layer, and reactive natural phosphate until 10–20 cm. Phosphorus application in furrows provides greater volume of soil with suitable levels of SOC, compared to broadcast application.O objetivo deste trabalho foi avaliar a distribuição vertical e horizontal do carbono orgânico do solo (CO) sob cinco manejos da adubação fosfatada, no sistema plantio direto. O experimento foi instalado sob Latossolo Vermelho, cultivado durante oito anos com soja ou milho, com milheto como planta de cobertura na entressafra. As parcelas foram submetidas aos tratamentos: aplicação de superfosfato triplo a lanço e no sulco, fosfato natural reativo a lanço e no sulco, e ausência de adição de fertilizante fosfatado (testemunha). A adição anual dos adubos fosfatados, na dose de 80 kg ha‑1 de P2O5, foi realizada em solo inicialmente com baixo teor de fósforo disponível. Amostras foram coletadas perpendicularmente à linha de plantio, em sete pontos distanciados a 12,5 cm, e cinco camadas: 0–2,5, 2,5–5,0, 5,0–10, 10–20 e 20–30 cm. O conteúdo e a distribuição do CO são afetados pela adubação fosfatada, tanto vertical quanto horizontalmente, com os maiores conteúdos observados nos tratamentos com adubos fosfatados. Em comparação com a testemunha, o superfosfato triplo apresentou maior conteúdo de CO até a camada de 5,0–10 cm, e o fosfato natural reativo até 10–20 cm. A aplicação de fósforo em sulcos proporciona maior volume de solo com teores adequados de CO, em comparação à aplicação a lanço

Stat1 nuclear translocation by nucleolin upon monocyte differentiation

BACKGROUND: Members of the signal transducer and activator of transcription (Stat) family of transcription factors traverse the nuclear membrane through a specialized structure, called the nuclear pore complex (NPC), which represents a selective filter for the import of proteins. Karyophilic molecules can bind directly to a subset of proteins of the NPC, collectively called nucleoporins. Alternatively, the transport is mediated via a carrier molecule belonging to the importin/karyopherin superfamily, which transmits the import into the nucleus through the NPC. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we provide evidence for an alternative Stat1 nuclear import mechanism, which is mediated by the shuttle protein nucleolin. We observed Stat1-nucleolin association, nuclear translocation and specific binding to the regulatory DNA element GAS. Using expression of nucleolin transgenes, we found that the nuclear localization signal (NLS) of nucleolin is responsible for Stat1 nuclear translocation. We show that this mechanism is utilized upon differentiation of myeloid cells and is specific for the differentiation step from monocytes to macrophages. CONCLUSIONS/SIGNIFICANCE: Our data add the nucleolin-Stat1 complex as a novel functional partner for the cell differentiation program, which is uniquely poised to regulate the transcription machinery via Stat1 and nuclear metabolism via nucleolin

The Palomar-Quest Digital Synoptic Sky Survey

We describe briefly the Palomar-Quest (PQ) digital synoptic sky survey, including its parameters, data processing, status, and plans. Exploration of the time domain is now the central scientific and technological focus of the survey. To this end, we have developed a real-time pipeline for detection of transient sources. We describe some of the early results, and lessons learned which may be useful for other, similar projects, and time-domain astronomy in general. Finally, we discuss some issues and challenges posed by the real-time analysis and scientific exploitation of massive data streams from modern synoptic sky surveys.Comment: Latex, 3 pages, 2 figures, macros included. To appear in refereed proceedings of "Hotwiring the Transient Universe 2007", eds. A. Allan, R. Seaman, and J. Bloom, Astron. Nachr. vol. 329, March, 200