37,265 research outputs found
Transfected aequorin in the measurement of cytosolic Ca2+ concentration ([Ca2+]c). A critical evaluation.
No full textTargeted recombinant aequorins represent to date the most specific means of monitoring [Ca2+] in subcellular organelles (Rizzuto, R., Simpson, A. W. M., Brini, M., and Pozzan, T. (1992) Nature 358, 325-328; Brini, M., Murgia, M., Pasti, L., Picard, D., Pozzan, T., and Rizzuto, R. (1993) EMBO J. 12, 4813-4819; Kendall, J. M., Dormer, R. L., and Campbell, A. K. (1992) Biochem. Biophys. Res. Commun. 189, 1008-1016). Up until now, however, only limited attention has been paid to the use of recombinant photoproteins for measuring, in mammalian cells, the [Ca2+] in the cytoplasm, a compartment for which effective Ca2+ probes are already available. Here we describe this approach in detail, highlighting the advantages, under various experimental conditions, of using recombinant cytosolic aequorin (cytAEQ) instead of classical fluorescent indicators. We demonstrate that cytAEQ is expressed recombinantly at high levels in transiently transfected cell lines and primary cultures as well as in stably transfected clones, and we describe a simple algorithm for converting aequorin luminescence data into [Ca2+] values. We show that although fluorescent indicators at the usual intracellular concentrations (50-100 microM) are associated with a significant buffering of the [Ca2+]c transients, this problem is negligible with recombinantly expressed aequorin. The large dynamic range of the photoprotein also allows an accurate estimate of the large [Ca2+]c increases that are observed in some cell types such as neurons. Finally, cytAEQ appears to be an invaluable tool for measuring [Ca2+]c in cotransfection experiments. In particular, we show that when cotransfected with an alpha 1-adrenergic receptor (coupled to inositol 1,4,5-trisphosphate generation), cytAEQ faithfully monitors the subpopulation of cells expressing the receptor, whereas the signal of fura-2, at the population level, is dominated largely by that of the untransfected cells
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Fluvial contributions of nutrient salts, dissolved trace elements and organic carbon to the sea by pristine temperate rivers (SW Europe).
No full textBernárdez, P., Ospina-Alvarez, N., Caetano, M., & Prego, R. (2013). Fluvial contributions of nutrient salts, dissolved trace elements and organic carbon to the sea by pristine temperate rivers (SW Europe). Environmental Chemistry, 10(1), 42–53. doi:http://dx.doi.org/10.1071/EN1212
The influence of summer upwelling at the western boundary of the Cantabrian coast
No full textPrego, R., Varela, M., DeCastro, M., Ospina-Alvarez, N., García-Soto, C., & Gómez-Gesteira, M. (2012). The influence of summer upwelling at the western boundary of the Cantabrian coast. Estuarine, Coastal and Shelf Science, 98, 138–144. doi:http://dx.doi.org/10.1016/j.ecss.2011.12.00
One-hundred aortic valve replacements in octogenarians: Outcomes and risk factors for early mortality
No full textBackground and aim of the study: Today, ageing of the western population is causing aortic valve surgery to be performed in elderly patients with increasing frequency. The study aim was to evaluate surgical outcome in octogenarian patients undergoing aortic valve replacement (AVR). Methods: A total of 100 patients (mean age 82.1 +/- 2.7 years; range: 80-95 years) who underwent AVR over a three-year period was reviewed. Concomitant coronary artery bypass grafting was performed in 34% of cases, and a bioprosthesis was implanted in 80%. The mean logistic EuroSCORE was 13.3%. Results: Operative mortality was 8.0%. In multivariate analysis, a logistic EuroSCORE >= 13.5% (p = 0.02), cross-clamp time >= 75 min (p = 0.02) and postoperative acute renal failure were predictors for in-hospital mortality. Follow up was 100% complete; the mean follow up period was 10.6 months. At one year after surgery, the actuarial survival rate of those patients who survived surgery was 86.1%. Postoperative dyspnea at one month (p = 0.004) was the only predictor of short-term mortality. Conclusion: Age in itself should not contraindicate surgery, and healthcare systems should be prepared to accommodate elderly patients who may require special resources
Rare earth elements in coastal sediments of the Northern Galician Shelf: influence of geological features
No full textPrego, R., Caetano, M., Bernardez, P., Brito, P., Ospina-Alvarez, N., & Vale, C. (2012). Rare earth elements in coastal sediments of the Northern Galician Shelf: influence of geological features. Continental Shelf Research, 35, 75–85. doi: http://dx.doi.org/10.1016/j.csr.2011.12.01
Effect Handlers for C via Coroutines - Artifact
No full textArtifact for the Effect Handlers for C via Coroutines paper published at OOPSLA 2024.Alvarez-Picallo, M., Freund, T., Ghica, D. R., & Lindley, S. (2024). Effect Handlers for C via Coroutines - Artifact. In Proceedings of the ACM on Programming Languages (Vol. 8, p. 358). Zenodo. https://doi.org/10.5281/zenodo.1361981
Socio-Economic Evaluation of the Terra Cha Irrigators Community by using a Geographic Information System - Spain
No full textRosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 6 (2004): J. Cancela, X. Neira, T. Cuesta, C. Alvarez, and R. Crecente. Socio-Economic Evaluation of the Terra Cha Irrigators Community by using a Geographic Information System - Spain. (July 2004)
Effects of initial conditions and Mach number in the evolution of Richtmyer-Meshkov instabilities
No full textWe present an experimental study of the effects of shock intensity and initial conditions on the evolution of Richtmyer-Meshkov Instabilities (RMI). This study is carried out in a vertical shock tube with a single interface of sulfur-hexafluoride and air. We use combined particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF) to obtain simultaneous measurements of velocity and density. These measurements enable us to determine single- and multi-point statistics of vector, scalar, and combined fields. We use these statistical descriptors to study the evolution of turbulence mixing in RMIs under different Mach numbers and initial conditions
- …
