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Widespread environmental impacts of frequent drought episodes in Brazil have resulted in several drought-related diagnostics studies. However, the potential of many "opportunistic sensors", such as the Global Positioning System (GPS), has not yet been considered in hydrological hazard monitoring in Brazil. In this study, the response of the Earth's crust to Brazil's 2012-2015 drought event in different structural provinces is analyzed by comparing GPS-observed vertical crustal deformations (VCDs) with the terrestrial water storage (TWS) derived from the Gravity Recovery and Climate Experiment (GRACE). The results indicate that there is no spatial correlation between annual amplitudes of the TWS and VCDs in different structural provinces apart from the purely elastic response of the crust to TWS dynamics, at almost all the 39 GPS stations that were analyzed. However, approximately 15% of the monitoring stations show that VCD leads TWS with a phase lag of 2-4 months. Errors associated with VCD and TWS are within the accepted range for space geodetic techniques (i.e., GPS and GRACE) and despite the need for further investigation, the phase lead seems to be associated with rainfall, which impacts the TWS through the hydrographs. Overall, the GPS-based drought index (DI VCD ) reflects the water depletion in many regions of Brazil, which agrees with the GRACE-based DI TWS in terms of the Spearman correlation coefficient (ranging from 0.4 to 0.9) in the Amazon, Tocantins, La Plata, and São Francisco river basins. This agreement confirms the drought persistence during the study period and that DI VCD can be used to monitor hydrological droughts. In regions in which DI TWS sufficiently agrees with DI VCD (48% of the sites), near real-time drought monitoring is feasible. This could be useful in the optimization of models for the forward prediction of drought events in other regions worldwide, where GPS vertical displacements strongly correlate with hydrological GRACE signals., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: Viruses are recognized as important agents of gastroenteritis outbreaks in institutions caring for dependent people. We aimed to define norovirus (NoV) and rotavirus (RV) immunochromatographic tests (ICT) and reverse transcription-polymerase chain reaction (RT-PCR) used in gastroenteritis investigations., Methods: Fourteen sites were monitored from 2010 to 2015, with 360 laboratory investigations. Twenty-two outbreaks and 44 sporadic case patients were investigated with ICTs (114 NoVs and 80 RVs) and RT-PCRs (114 NoVs and 52 RVs)., Results: ICTs were useful during outbreaks (identification of NoVs and RVs in respectively 76.5% and 75.0% of episodes) despite the NoV sensitivity limit (55.1%) and the four RV false positive results observed for 10 samples. Given the NoV ICT performance and the observed variations of the NoV and RV prevalence (between 20.0% and 5.0%), ICTs are not appropriate to identify sporadic gastroenteritis case patients. Positive predictive values <60.0% were observed when the prevalence of RV and NoV was low (<5.0%). NoV and RV RT-PCR indications are sporadic gastroenteritis case patients, negative NoV and RV ICT during outbreaks, control of positive RV ICT in cases of suspected NoV and RV co-circulation, patients with long symptom duration, and NoV genogroup and genotype identifications (infection control and epidemiological surveillance). Inclusion of patients with specific clinical symptoms is recommended irrespective of the technique., Conclusion: On the basis of the ICT limits identified in this work, RT-PCR development seems essential to improve viral gastroenteritis investigations in institutions caring for dependent people., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Early events of protein folding can be studied with fast perturbation techniques triggering non-equilibrium relaxation dynamics. A nanosecond laser-excited pH-jump or temperature-jump (T-jump) was applied to initiate helix folding or unfolding of poly-l-glutamic acid (PGA). PGA is a homopolypeptide with titratable carboxyl side-chains whose protonation degree determines the PGA conformation. A pH-jump was realized by the photochemical release of protons and induces PGA folding due to protonation of the side-chains. Otherwise, the helical conformation can be unfolded by a T-jump. We operated under conditions where PGA does not aggregate and temperature and pH are the regulatory properties of its conformation. The experiments were performed in such a manner that the folding/unfolding jump proceeded to the same PGA conformation. We quantified the increase/decrease in helicity induced by the pH-/T-jump and demonstrated that the T-jump results in a relatively small change in helical content in contrast to the pH-jump. This is caused by the strong pH-dependence of the PGA conformation. The conformational changes were detected by time-resolved single wavelength IR-spectroscopy using quantum cascade lasers (QCL). We could independently observe the kinetics for α-helix folding and unfolding in PGA by using different perturbation techniques and demonstrate the high sensitivity of time-resolved IR-spectroscopy to study protein folding mechanisms., (Copyright © 2017 Elsevier B.V. All rights reserved.)