Wednesday, August 27, 2014

 

 



Soy un nuevo usuario

Olvidé mi contraseña

Entrada usuarios

Lógica Matemáticas Astronomía y Astrofísica Física Química Ciencias de la Vida
Ciencias de la Tierra y Espacio Ciencias Agrarias Ciencias Médicas Ciencias Tecnológicas Antropología Demografía
Ciencias Económicas Geografía Historia Ciencias Jurídicas y Derecho Lingüística Pedagogía
Ciencia Política Psicología Artes y Letras Sociología Ética Filosofía
 

rss_1.0 Clasificación por Disciplina

Nomenclatura Unesco > (25) Ciencias de la Tierra y Espacio > (2501) Ciencias de la atmósfera > (2501.13) Auroras

Mostrando recursos 1 - 20 de 12,593

1. Extended infrared photoresponse and gain in chalcogen-supersaturated silicon photodiodes - Said, Aurore J.; Recht, Daniel; Sullivan, Joseph T.; Warrender, Jeffrey M.; Buonassisi, Tonio; Persans, Peter D.; Aziz, Michael J.
Highly supersaturated solid solutions of selenium or sulfur in silicon were formed by ion implantation followed by nanosecond pulsed laser melting. n+p photodiodesfabricated from these materials exhibit gain (external quantum efficiency >3000%) at 12 V of reverse bias and substantial optoelectronic response to light of wavelengths as long as 1250 nm. The amount of gain and the strength of the extended response both decrease with decreasing magnitude of bias voltage, but >100% external quantum efficiency is observed even at 2 V of reverse bias. The behavior is inconsistent with our expectations for avalanche gain or photoconductive gain.

2. Insulator-to-Metal Transition in Sulfur-Doped Silicon - Winkler, Mark T.; Recht, Daniel; Sher, Meng-Ju; Said, Aurore J.; Mazur, Eric; Aziz, Michael J.
We observe an insulator-to-metal transition in crystalline silicon doped with sulfur to nonequilibrium concentrations using ion implantation followed by pulsed-laser melting and rapid resolidification. This insulator-to-metal transition is due to a dopant known to produce only deep levels at equilibrium concentrations. Temperature-dependent conductivity and Hall effect measurements for temperatures T>1.7  K both indicate that a transition from insulating to metallic conduction occurs at a sulfur concentration between 1.8 and 4.3×1020  cm−3. Conduction in insulating samples is consistent with variable-range hopping with a Coulomb gap. The capacity for deep states to effect metallic conduction by delocalization is the only known route to bulk...

3. Complications Dawn for Kinetochore Regulation by Aurora - Nannas, Natalie; Murray, Andrew W.
Organisms must faithfully segregate their chromosomes during cell division; mistakes in this process can be costly and even fatal to the organism (1, 2). During mitosis, replicated chromosomes attach to the spindle, a dynamic system of microtubules organized around two poles. Chromosomes attach to the spindle via kinetochores, structures that form on centromeres and bind the ends of microtubules. For accurate segregation, kinetochores on sister chromosomes must attach to microtubules from opposite poles; incorrect attachments lead to missegregation (3). In PNAS, Umbreit et al. (4) expand our understanding of how kinetochore–microtubule interactions can be regulated to correct improper attachments. The...

4. Soil infrastructure evolution and its effect on water transfer processes under contrasted tillage systems - overview of methodologies with preliminary results - Parvin, Nargish; Colinet, Gilles; Garré, Sarah; Bodson, Bernard; Chelin, Marie; Degré, Aurore
The heterogeneity of soil structure and porosity are highly influenced by external factors like tillage systems and other land management approaches. The aim of this project is to investigate the effect of soil tillage along with residue management on the changing pattern of soil structure. This investigation will help to emphasize the different water flow dynamics especially the preferential flow processes through the soil that are influenced by the changes in structural distribution in the soil profile. The experimentation has been started from June 2013 in the research field in Gembloux. Soil profile description together with soil sampling has been...

5. The STRA6 Receptor Is Essential for Retinol-binding Protein-induced Insulin Resistance but Not for Maintaining Vitamin A Homeostasis in Tissues Other Than the Eye* - Berry, Daniel C.; Jacobs, Hugues; Marwarha, Gurdeep; Gely-Pernot, Aurore; O'Byrne, Sheila M.; DeSantis, David; Klopfenstein, Muriel; Feret, Betty; Dennefeld, Christine; Blaner, William S.; Croniger, Colleen M.; Mark, Manuel; Noy, Noa; Ghyselinck, Norbert B.
Background: STRA6 transports retinol into cells and activates cell signaling.

6. Is solar variability reflected in the Nile River? - Ruzmaikin, Alexander; Feynman, Joan; Yung, Yuk L.
We investigate the possibility that solar variability influences North African climate by using annual records of the water level of the Nile collected in 622–1470 A.D. The time series of these records are nonstationary, in that the amplitudes and frequencies of the quasi-periodic variations are time-dependent. We apply the Empirical Mode Decomposition technique especially designed to deal with such time series. We identify two characteristic timescales in the records that may be linked to solar variability: a period of about 88 years and one exceeding 200 years. We show that these timescales are present in the number of auroras reported...

7. Ultraviolet Imaging Spectroscopy shows an active saturnian system - Esposito, Larry W.; Colwell, Joshua E.; Larsen, Kristopher; McClintock, William E.; Stewart, A. Ian F.; Hallett, Janet Tew; Shemansky, Donald E.; Ajello, Joseph M.; Hansen, Candice J.; Hendrix, Amanda R.; West, Robert A.; Keller, H. Uwe; Korth, Axel; Pryor, Wayne R.; Reulke, Ralf; Yung, Yuk L.
Neutral oxygen in the saturnian system shows variability, and the total number of oxygen atoms peaks at 4 x 10^(34). Saturn’s aurora brightens in response to solar-wind forcing, and the auroral spectrum resembles Jupiter’s. Phoebe’s surface shows variable water-ice content, and the data indicate it originated in the outer solar system. Saturn’s rings also show variable water abundance, with the purest ice in the outermost A ring. This radial variation is consistent with initially pure water ice bombarded by meteors, but smaller radial structures may indicate collisional transport and recent renewal events in the past 10^7 to 10^8 years.

8. Dataset compiling oceanic volumetric (mmol O2 or C m-3 d-1) metabolism rates from the dark-light method (GPP-DO), the 14C method (14C-TOC for total organic carbon and 14C-POC for particulate organic production), the 18O method (GPP-18O), the FRRF method (GPP-O2-FRRF) and the 13C method (13C-POC) from published works - Regaudie de Gioux, Aurore; Lasternas, Sebastien; Agustí, Susana; Duarte, Carlos M.
The data set includes published data for volumetric estimates of primary production of natural marine plankton communities produced using at least two different methods applied concurrently. Here, we present and compare the following methods: the oxygen evolution in dark and light incubations (Carpenter 1965; Carrit and Carpenter 1966), the FRRF method (Kolber and Falkowski 1993) and methods based in tracer additions (18O (Bender et al. 1987), 14C (Steeman Nielsen 1952) and 13C (Slawyk et al. 1977)).

9. Acerca de un arte de género en la Argentina contemporánea - Carral, Aurora Mabel
Las artes contemporáneas, en su complejización, no escapan del contexto de globalización económica –cultural y multiculturalismo del mundo actual, por consiguiente cuando hacemos un paneo del arte de fines del Siglo XX y principios del Siglo XXI, nos encontramos con un prisma que se deconstruye constantemente; múltiples fragmentaciones operan y exploran nuevas sensibilidades. Esta ponencia realiza una aproximación a manifestaciones estéticas producidas por artistas mujeres en la Argentina contemporánea desde una perspectiva de género. Su intención no es otra que comprender cómo estas mujeres artistas reflejan en sus obras subjetividades relacionadas a su identidad produciendo diversos sentidos. Esta labor de...

10. Aurora. - Stefanich, Juan, b. 1889
Detached from various issues of Los Anales del Gimnasio Paraguayo.

11. Mujer y arte público: prácticas artísticas de denuncia social - Lombardelli, Martha Alicia; Carral, Aurora Mabel
El presente trabajo se inscribe en el marco del Programa de Incentivo a los Docentes Investigadores. Constituye una aspecto del proyecto de investigación que implementamos a partir del 1º de enero de 2006, denominado: Mujer: distintas lecturas de la construcción de la imagen femenina a través de la perspectiva crítica de género en diversos soportes discursivos en la argentina del siglo XX. La superficie urbana visualmente cubierta de estímulos pertenecientes al arte público, el cual inscribe día a día su presencia, instaura diversas formas de representaciones creando espacios diferenciales de compromiso y reflexión por parte de distintos actores sociales. Previo...

12. Arte memoria y espacio público: intervención urbana - Carral, Aurora Mabel
La experiencia que deseamos compartir en estas Jornadas, se centra en la intervención urbana denominada «30 años no es nada... Entre memoria y olvido», que realizamos en marzo de 2006 en la ciudad de La Plata con motivo de conmemorarse el día 24 de marzo los treinta años del último golpe militar. Mediante ella tratamos de poner de manifiesto la presencia crítica del arte público reconociendo la ciudad como un continente de identidades colectivas, donde la memoria de cada uno se encuentra con la de otros, estableciendo una interactividad. Diversas actividades, como talleres de producción con jóvenes funcionaron como estímulo...

13. Projeto Aurora : processamento paralelo com processadores transputers - Sutil, Cleverson Borges

14. Benzene and Haze Formation in the Polar Atmosphere of Jupiter - Wong, Ah-San; Yung, Yuk L.; Friedson, A. James
Jupiter has a large magnetosphere that episodically precipitates large amounts of energy into the polar atmosphere, giving rise to intense auroras [Clarke et al., 1996; Grodent et al., 2000]. An important consequence of this energy influx is the production of a dark haze [Pryor and Hord, 1991], the formation mechanism of which was hitherto poorly known. Recent observations of benzene on Jupiter [Bézard et al., 2001; Flasar, 2002] provide new clues for a chemical and aerosol model for the formation of heavy hydrocarbon aerosols. The chemistry begins with the destruction of methane by energetic particles, followed by neutral and ion...

15. Recorridos desde el arte para la construcción de la memoria colectiva - Carral, Aurora Mabel
En esta oportunidad presentamos uno de los recorridos denominado «Registros Visuales»; para la realización del mismo se optó por elegir ocho registros visuales que anclan momentos históricos relacionados con estas representaciones paradigmáticas, producciones significativas para la construcción de saberes en los visitantes a la muestra. Las producciones que conforman este guión intenta operar como metáfora visual de la intensidad de la violencia del terrorismo de estado llevado adelante por el gobierno de facto de 1976-1983. Desde este lugar se pretende una doble finalidad pedagógica al articular por un lado la comprensión estética y por el otro proporcionar elementos para la...

16. Local time variations in Jupiter's magnetosphere-ionosphere coupling system - Ray, LC; Achilleos, NA; Yates, JN; Vogt, MF
The ionization of neutral material ejected by Jupiter's volcanically active moon, Io, results in a plasma disc that extends from Io's orbit out through the Jovian magnetosphere. This magnetospheric plasma is coupled to the planetary ionosphere via currents which flow along the magnetic field. Inside of ∼40-R, these currents transfer angular momentum from the planet to the magnetospheric plasma, in an attempt to keep the plasma rigidly corotating with the planet. Jupiter's main auroral emission is a signature of this current system. To date, one-dimensional models of Jupiter's magnetosphere-ionosphere (M-I) coupling have either assumed a dipole field or used a...

17. Polo-like kinase 1 (PLK1) and protein phosphatase 6 (PP6) regulate DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation in mitosis - Douglas, Pauline; Ye, Ruiqiong; Trinkle‑Mulcahy, Laura; Neal, Jessica A.; De Wever, Veerle; Morrice, Nick A.; Meek, Katheryn; Lees‑Miller, Susan P.
The protein kinase activity of the DNA-PKcs (DNA-dependent protein kinase catalytic subunit) and its autophosphorylation are critical for DBS (DNA double-strand break) repair via NHEJ (non-homologous end-joining). Recent studies have shown that depletion or inactivation of DNA-PKcs kinase activity also results in mitotic defects. DNA-PKcs is autophosphorylated on Ser2056, Thr2647 and Thr2609 in mitosis and phosphorylated DNA-PKcs localize to centrosomes, mitotic spindles and the midbody. DNA-PKcs also interacts with PP6 (protein phosphatase 6), and PP6 has been shown to dephosphorylate Aurora A kinase in mitosis. Here we report that DNA-PKcs is phosphorylated on Ser3205 and Thr3950 in mitosis. Phosphorylation of...

18. Diseño de quelatos de lantánidos de alta estabilidad con interés en imagen molecular: Design de chélates de lanthanides à haute stabilité avec intérêt en imagerie moléculaire - Rodríguez Rodríguez, Aurora
La presente Tesis Doctoral se ha centrado en la búsqueda de nuevos quelatos de lantánidos de elevada estabilidad y versatilidad en su posible funcionalización, así como en su potencial interés como sondas en técnicas de Imagen Molecular, especialmente en la Imagen por Resonancia Magnética (IRM). Para ello, se ha tomado como punto de partida el [Gd(dota)(H2O)]-, que es el principio activo del Dotarem® (el agente de contraste más utilizado en clínica). La idea ha sido rediseñar el ligando dota4-, incorporando cadenas colgantes de naturaleza bidentada en sustitución de los grupos carboxilato (monodentados) que presenta este ligando. De esta manera, se...

19. Minimal-Delay Distance Transform for Neighborhood-Sequence Distances in 2D and 3D - Nicolas Normand; Robin Strand; Pierre Evenou; Aurore Arlicot

20. PYME dedicada a las bodas: un modelo turístico diferente - Espartero Vázquez, Aurora; Vázquez Bermúdez, Isabel
The idea of a more practical, also experiential (based in the experience achievedby performing activities), aimed to spend our leisure time in an attractive manner, but at the same time, tourism is getting us to serve other purposes as a new form of tourism. In this case, to go to a brides social club and participate in all activities proposed (like tourism) is a good example of this definition. Sevilla is the city where study the social impact that would result in the implementation of an enterprise of these characteristics.

Página de resultados:
 

Busque un recurso