A robust data cleaning procedure for eddy covariance flux measurements

Abstract. The sources of systematic error responsible for introducing significant biases in the eddy covariance (EC) flux computation are manifold, and their correct identification is made difficult by the lack of reference values, by the complex stochastic dynamics, and by the high level of noise characterizing raw data. This work contributes to overcoming such challenges by introducing an innovative strategy for EC data cleaning. The proposed strategy includes a set of tests aimed at detecting the presence of specific sources of systematic error, as well as an outlier detection procedure aimed at identifying aberrant flux values. Results from tests and outlier detection are integrated in such a way as to leave a large degree of flexibility in the choice of tests and of test threshold values, ensuring scalability of the whole process. The selection of best performing tests was carried out by means of Monte Carlo experiments, whereas the impact on real data was evaluated on data distributed by the Integrated Carbon Observation System (ICOS) research infrastructure. Results evidenced that the proposed procedure leads to an effective cleaning of EC flux data, avoiding the use of subjective criteria in the decision rule that specifies whether to retain or reject flux data of dubious quality. We expect that the proposed data cleaning procedure can serve as a basis towards a unified quality control strategy for EC datasets, in particular in centralized data processing pipelines where the use of robust and automated routines ensuring results reproducibility constitutes an essential prerequisite

Saccharomyces boulardii: a summary of the evidence for gastroenterology clinical practice in adults and children.

Probiotics are viable, nonpathogenic microorganisms (bacteria or yeast) which when administered in adequate amounts, confer a health benefit on the host. At this time, Saccharomyces boulardii is the only yeast commonly used in clinical practice. Literature on this probiotic is wide and even more data become available each year. Thus, it could be problematic for a physician summarize all the best information deriving from basic research and clinical studies. With the aim to help physicians in the use of Saccharomyces boulardii, this paper focuses on the available evidences for its efficacy and safety in different diseases in adult and pediatric patients in order to provide a practical guidance for gastroenterology clinical practice. Indications and dosage for several gastrointestinal diseases for a correct use of this probiotic are provided, and recent insights on its mechanisms of action and possible future clinical application are also discussed

Bostonia: v. 64, no. 1

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Role of nucleus accumbens μ opioid receptors in the effects of morphine on ERK1/2 phosphorylation

Rationale: Despite the critical role attributed to phosphorylated extracellular signal regulated kinase (pERK1/2) in the nucleus accumbens (Acb) in the actions of addictive drugs, the effects of morphine on ERK1/2 phosphorylation in this area are still controversial. Objectives: In order to investigate further this issue, we studied (1) the ability of morphine to affect ERK1/2 phosphorylation in the shell (AcbSh) and core (AcbC) of Sprague-Dawley and Wistar rats and of CD-1 and C57BL/6J mice and (2) the role of dopamine D1 and μ-opioid receptors in Sprague-Dawley rats and CD-1 mice. Methods: The pERK1/2 expression was assessed by immunohistochemistry. Results: In rats, morphine decreased AcbSh and AcbC pERK1/2 expression, whereas in mice, increased it preferentially in the AcbSh compared with the AcbC. Systemic SCH 39166 decreased pERK1/2 expression on its own in the AcbSh and AcbC of Sprague-Dawley rats and CD-1 mice; furthermore, in rats, SCH 39166 disclosed the ability of morphine to stimulate pERK1/2 expression. Systemic (rats and mice) and intra-Acb (rats) naltrexone prevented both decreases, in rats, and increases, in mice. Conclusions: These findings confirm the differential effects of morphine in rats and mice Acb and that D1 receptors exert a facilitatory role on ERK1/2 phosphorylation; furthermore, they indicate that, in rats, removal of the D1-dependent pERK1/2 expression discloses the stimulatory influence of morphine on ERK1/2 phosphorylation and that the morphine’s ability to decrease pERK1/2 expression is mediated by Acb μ-opioid receptors. Future experiments may disentangle the psychopharmacological significance of the effects of morphine on pERK1/2 in the Acb

International cooperation during volcanic crisis: an example from the Italy-El Salvador monitoring system installed at Chaparrastique volcano, El Salvador

On December 29th, 2013, after 12 years of inactivity, a new explosive eruption occurred at Chaparrastique volcano (San Miguel, el Salvador) prompting the evacuation of more than 5000 people. The new eruption that occurred at the volcano has so far been an isolated single explosion of vulcanian type, and was the first eruption since 2002, when the volcano produced a small VEI 1 eruption. The explosion produced an ash plume of considerable (5-10 km) height, generating heavy ash fall in nearby areas downwind, such as in the towns of Chinameca and San Jorge. Pyroclastic density currents also affected the flanks, damaging the coffee plantations and small inhabited areas around the volcano. On January 2014, following a request of support by the government of El Salvador, INGV (Istituto Nazionale di Geofisica e Vulcanologia), organized a task force, V-Emer (Volcano Emergency) to improve the existing monitoring network at Chaparrastque volcano. During a 10 days campaign in El Salvador a temporary network was successfully installed, and it is now run by the volcanologists of MARN (Ministerio de Medio Ambiente y Recursos Naturales, El Salvador). The network is composed of five broadband seismic stations, 3 infrasonic microphones, 2 radiometers, 10 GPS stations, 1 thermal camera, 1 DOAS and 1 multi-gas geochemical station for measurement of SO2 and CO2 fluxes, respectively. Since 27 January, significant collaborative efforts are being done between MARN and INGV for the processing and interpretation of the data collected during monitoring. For facilitating communication and exchange between the members of the cooperation, a mailing list has been created, and weekly meetings are attended by the members for the discussion on a number of scientific and technical aspects. This initiative seeks to make significant advance into volcano monitoring network and data analysis, as well as improving international cooperation during volcanic crisis management. V-EMER group: A. Bonforte, G. Giuffrida,A. La Spina, F. Montalvo, M. Liuzzo, S. Rapisarda, G. Salerno, D. Andronico, E. Biale, A. Cannata, T. Caltabiano, E. Del Bello, M. La Rocca, D. Granieri, L. Lodato, G. Giudice, F. Murè, E. Pecora, M. Prestifilippo, L. Scuderi, L. Zuccarello, G. De Natale, R. Favara, E. Privitera. MARN group: M. Diaz, D. Escobar, E. Gutierrez, D. Hernandez, G. Marroquin, C. Bolaños, L. Handal, C. Polío, B. Palacios, N. Galvez, R. Torres, E. Escobar

Remote sensing of ecosystem light use efficiency with MODIS-based PRI

Several studies sustained the possibility that a photochemical reflectance index (PRI) directly obtained from satellite data can be used as a proxy for ecosystem light use efficiency (LUE) in diagnostic models of gross primary productivity. This modelling approach would avoid the complications that are involved in using meteorological data as constraints for a fixed maximum LUE. However, no unifying model predicting LUE across climate zones and time based on MODIS PRI has been published to date. In this study, we evaluate the effectiveness with which MODIS-based PRI can be used to estimate ecosystem light use efficiency at study sites of different plant functional types and vegetation densities. Our objective is to examine if known limitations such as dependence on viewing and illumination geometry can be overcome and a single PRI-based model of LUE (i.e. based on the same reference band) can be applied under a wide range of conditions. Furthermore, we were interested in the effect of using different faPAR (fraction of absorbed photosynthetically active radiation) products on the in-situ LUE used as ground truth and thus on the whole evaluation exercise. We found that estimating LUE at site-level based on PRI reduces uncertainty compared to the approaches relying on a maximum LUE reduced by minimum temperature and vapour pressure deficit. Despite the advantages of using PRI to estimate LUE at site-level, we could not establish an universally applicable light use efficiency model based on MODIS PRI. Models that were optimised for a pool of data from several sites did not perform well

Eddy Covariance flux errors due to random and systematic timing errors during data acquisition

Modern eddy covariance (EC) systems collect high-frequency data (10–20 Hz) via digital outputs of instru ments. This is an important evolution with respect to the tra ditional and widely used mixed analog/digital systems, as fully digital systems help overcome the traditional limita tions of transmission reliability, data quality, and complete ness of the datasets