βCaMKII regulates bidirectional long-term plasticity in cerebellar Purkinje cells by a CaMKII/PP2B switch mechanism

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise statedPeer reviewe

Robust Gravitational Wave Burst Detection and Source Localization in a Network of Interferometers Using Cross Wigner Spectra

We discuss a fast cross-Wigner transform based technique for detecting gravitational wave bursts, and estimating the direction of arrival, using a network of (three) non co-located interferometric detectors. The performances of the detector as a function of signal strength and source location, and the accuracy of the direction of arrival estimation are investigated by numerical simulations.Comment: accepted in Class. Quantum Gravit

Modeling the Impulsive Noise Component and its Effect on the Operation of a Simple Coherent Network Algorithm for Unmodeled Gravitational Wave Bursts Detection

An analytic model a la Middleton of the impulsive noise component in the data of interferometric gravitational wave detectors is proposed, based on an atomic representation of glitches. A fully analytic characterization of the coherent network data analysis algorithm proposed by Rakhmanov and Klimenko is obtained, for the simplest relevant case of triggered detection of unmodeled gravitational wave bursts, using the above noise model. The detector's performance is evaluated under a suitable central-limit hypothesis, and the effects of both the noisiness of the pseudo-templates, and the presence of the impulsive noise component are highlighted.Comment: 15 pages, 8 figure

In search of lost time constants and of non-Michaelis–Menten parameters

SummaryUpon completing 100 years since it was published, the work Die Kinetik der Invertinwirkung by Michaelis and Menten (MM) was celebrated during the 6th Beilstein ESCEC Symposium 2013. As the 7th Beilstein ESCEC Symposium 2015 debates enzymology in the context of complex biological systems, a post-MM approach is required to address cell-like conditions that are well beyond the steady-state limitations. The present contribution specifically addresses two hitherto ambiguous constants whose interest was, however, intuited in the original MM paper: (i) the characteristic time constant τ∞, which can be determined using the late stages of any progress curve independently of the substrate concentration adopted; and (ii) the dissociation constant KS, which is indicative of the enzyme–substrate affinity and completes the kinetic portrayal of the Briggs–Haldane reaction scheme. The rationale behind τ∞ and KS prompted us to revise widespread concepts of enzyme's efficiency, defined by the specificity constant kcat/KM, and of the Michaelis constant KM seen as the substrate concentration yielding half-maximal rates. The alternative definitions here presented should help recovering the wealth of published kcat/KM and KM data from the criticism that they are subjected. Finally, a practical method is envisaged for objectively determining enzyme's activity, efficiency and affinity – (EA)2 – from single progress curves. The (EA)2 assay can be conveniently applied even when the concentrations of substrate and enzyme are not accurately known

An integrative assessment to determine the genotoxic hazard of estuarine sediments: combining cell and whole-organism responses

The application of the Comet assay in environmental monitoring remains challenging in face of the complexity of environmental stressors, e.g., when dealing with estuarine sediments, that hampers the drawing of cause-effect relationships. Although the in vitro Comet assay may circumvent confounding factors, its application in environmental risk assessment (ERA) still needs validation. As such, the present work aims at integrating genotoxicity and oxidative DNA damage induced by sediment-bound toxicants in HepG2 cells with oxidative stress-related effects observed in three species collected from an impacted estuary. Distinct patterns were observed in cells exposed to crude mixtures of sediment contaminants from the urban/industrial area comparatively to the ones from the rural/riverine area of the estuary, with respect to oxidative DNA damage and oxidative DNA damage. The extracts obtained with the most polar solvent and the crude extracts caused the most significant oxidative DNA damage in HepG2 cells, as measured by the formamidopyrimidine-DNA glycosylase (FPG)-modified Comet assay. This observation suggests that metals and unknown toxicants more hydrophilic than polycyclic aromatic hydrocarbons may be important causative agents, especially in samples from the rural part of the estuary, where oxidative DNA damage was the most significant. Clams, sole, and cuttlefish responded differentially to environmental agents triggering oxidative stress, albeit yielding results accordant with the oxidative DNA damage observed in HepG2 cells. Overall, the integration of in vivo biomarker responses and Comet assay data in HepG2 cells yielded a comparable pattern, indicating that the in vitro FPG-modified Comet assay may be an effective and complementary line-of-evidence in ERA even in particularly challenging, natural, scenarios such as estuarine environments

Development of a metric of aquatic invertebrates for volunteers (MAIV): a simple and friendly biotic metric to assess ecological quality of streams

Citizen science activities, involving local people in volunteer-supported and sustainable monitoring programs, are common. In this context, the objective of the present work was to develop a simple Metric of Aquatic Invertebrates for Volunteers (MAIV), including a user-friendly tool that can be easily accessed by volunteers, and to evaluate the e ciency of a volunteer monitoring program following an audit procedure. To obtain MAIV values, macroinvertebrate communities were reduced to 18 surrogate taxa, which represented an acceptable compromise between simplicity, e ciency, and reproducibility of the data, compared to the regular Water Framework Directive monitoring. When compared to results obtained with the National Classification System of Portugal, MAIV accurately detected moderate, poor, and bad ecological status. Thus, MAIV can be used by volunteers as a complement to the o cial monitoring program, as well as a prospective early warning tool for local problems related to ecological quality. Volunteers were students supervised by their teachers. Results obtained by volunteers were compared to results obtained by experts on macroinvertebrate identification to measure the e ciency of the procedure, by counting gains and losses on sorting, and identification. Characteristics of groups of volunteers (age and school level) did not influence significantly the e ciency of the procedure, and generally results of volunteers and experts matched.info:eu-repo/semantics/publishedVersio

Glutaraldehyde-crosslinking chitosan scaffolds reinforced with calcium phosphate spray-dried granules for bone tissue applications

The clinical demand for bone scaffolds as an alternative strategy for bone grafting has increased exponentially and, up to date, numerous formulations have been proposed to regenerate the bone tissue. However, most of these structures lack at least one of the fundamental/ideal properties of these materials (e.g., mechanical resistance, interconnected porosity, bioactivity, biodegradability, etc.). In this work, we developed innovative composite scaffolds, based on crosslinked chitosan with glutaraldehyde (GA), combined with different atomized calcium phosphates (CaP) granules - hydroxyapatite (HA) or biphasic mixtures of HA and β - tricalcium phosphate (β-TCP), with improved biomechanical behavior and enhanced biological response. This innovative combination was designed to improve the scaffolds' functionality, in which GA improved chitosan mechanical strength and stability, whereas CaP granules enhanced the scaffolds' bioactivity and osteoblastic response, further reinforcing the scaffolds' structure. The biological assessment of the composite scaffolds showed that the specimens with 0.2% crosslinking were the ones with the best biological performance. In addition, the inclusion of biphasic granules induced a trend for increase osteogenic activation, as compared to the addition of HA granules. In conclusion, scaffolds produced in the present work, both with HA granules or the biphasic ones, and with low concentrations of GA, have shown adequate properties and enhanced biological performance, being potential candidates for application in bone tissue engineering.publishe