Realization of a superconducting atom chip

We have trapped rubidium atoms in the magnetic field produced by a superconducting atom chip operated at liquid Helium temperatures. Up to $8.2\cdot 10^5$ atoms are held in a Ioffe-Pritchard trap at a distance of 440 $\mu$m from the chip surface, with a temperature of 40 $\mu$K. The trap lifetime reaches 115 s at low atomic densities. These results open the way to the exploration of atom--surface interactions and coherent atomic transport in a superconducting environment, whose properties are radically different from normal metals at room temperature.Comment: Submitted to Phys. Rev. Let

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

DWM07 global empirical model of upper thermospheric storm-induced disturbance winds

We present a global empirical disturbance wind model (DWM07) that represents average geospace-storm-induced perturbations of upper thermospheric (200-600 km altitude) neutral winds. DWM07 depends on the following three parameters: magnetic latitude, magnetic local time, and the 3-h Kp geomagnetic activity index. The latitude and local time dependences are represented by vector spherical harmonic functions ( up to degree 10 in latitude and order 3 in local time), and the Kp dependence is represented by quadratic B-splines. DWM07 is the storm time thermospheric component of the new Horizontal Wind Model (HWM07), which is described in a companion paper. DWM07 is based on data from the Wind Imaging Interferometer on board the Upper Atmosphere Research Satellite, the Wind and Temperature Spectrometer on board Dynamics Explorer 2, and seven ground-based Fabry-Perot interferometers. The perturbation winds derived from the three data sets are in good mutual agreement under most conditions, and the model captures most of the climatological variations evident in the data

Paleobiology of a Large Mammal Community From the Late Pleistocene of Sonora, Mexico

A paleontological deposit near San Clemente de Térapa represents one of the very few Rancholabrean North American Land Mammal Age sites within Sonora, Mexico. During that time, grasslands were common, and the climate included cooler and drier summers and wetter winters than currently experienced in northern Mexico. Here, we demonstrate restructuring in the mammalian community associated with environmental change over the past 40,000 years at Térapa. The fossil community has a similar number of carnivores and herbivores whereas the modern community consists mostly of carnivores. There was also a 97% decrease in mean body size (from 289 kg to 9 kg) because of the loss of megafauna. We further provide an updated review of ungulates and carnivores, recognizing two distinct morphotypes of Equus, including E. scotti and a slighter species; as well as Platygonus compressus; Camelops hesternus; Canis dirus; and Lynx rufus; and the first regional records of Palaeolama mirifica, Procyon lotor, and Smilodon cf. S. fatalis. The Térapa mammals presented here provide a more comprehensive understanding of the faunal community restructuring that occurred in northern Mexico from the late Pleistocene to present day, indicating further potential biodiversity loss with continued warming and drying of the region

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

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

Bose-Einstein condensation on a superconducting atom chip

We have produced a Bose-Einstein condensate (BEC) on an atom chip using only superconducting wires in a cryogenic environment. We observe the onset of condensation for 10^4 atoms at a temperature of 100 nK. This result opens the way for studies of atom losses and decoherence in a BEC interacting with a superconducting surface. Studies of dipole-blockade with long-lived Rydberg atoms in a small and dense atomic sample are underway.Comment: 4 pages, 4 figures. Accepted for publication in Europhysics Letter

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