Prefrontal control over motor cortex cycles at beta-frequency during movement inhibition

A fully adapted behavior requires maximum efficiency to inhibit processes in the motor domain [ 1 ]. Although a number of cortical and subcortical brain regions have been implicated, converging evidence suggests that activation of right inferior frontal gyrus (r-IFG) and right presupplementary motor area (r-preSMA) is crucial for successful response inhibition [ 2, 3 ]. However, it is still unknown how these prefrontal areas convey the necessary signal to the primary motor cortex (M1), the cortical site where the final motor plan eventually has to be inhibited or executed. On the basis of the widely accepted view that brain oscillations are fundamental for communication between neuronal network elements [ 4–6 ], one would predict that the transmission of these inhibitory signals within the prefrontal-central networks (i.e., r-IFG/M1 and/or r-preSMA/M1) is realized in rapid, periodic bursts coinciding with oscillatory brain activity at a distinct frequency. However, the dynamics of corticocortical effective connectivity has never been directly tested on such timescales. By using double-coil transcranial magnetic stimulation (TMS) and electroencephalography (EEG) [ 7, 8 ], we assessed instantaneous prefrontal-to-motor cortex connectivity in a Go/NoGo paradigm as a function of delay from (Go/NoGo) cue onset. In NoGo trials only, the effects of a conditioning prefrontal TMS pulse on motor cortex excitability cycled at beta frequency, coinciding with a frontocentral beta signature in EEG. This establishes, for the first time, a tight link between effective cortical connectivity and related cortical oscillatory activity, leading to the conclusion that endogenous (top-down) inhibitory motor signals are transmitted in beta bursts in large-scale cortical networks for inhibitory motor control

Novel Measurement Technique of the Tibial Slope on Conventional MRI

The posterior inclination of the tibial plateau, which is referred to as posterior tibial slope, is determined routinely on lateral radiographs. However, radiographically, it is not always possible to reliably recognize the lateral plateau, making a separate assessment of the medial and lateral plateaus difficult. We propose a technique to measure the plateaus separately by defining a tibial longitudinal axis on a conventional MRI. The medial plateau posterior tibial slope obtained from radiographs was compared with MR images in 100 consecutive patients with knee pain when ligament or meniscal injury was assumed. The posterior tibial slope on MRI correlated with those on radiographs. The mean posterior tibial slope was 3.4° smaller on MRI compared with radiographs (4.8°±2.4° versus 8.2°±2.8°, respectively). The reproducibility was slightly better on radiographs than MRI (±0.9° versus±1.4°). Twenty-one of the 100 cases had more than a 5° difference (range, −8.7° to 8.9°) between the medial and lateral plateaus. The proposed technique allows measurement of the posterior tibial slope of the medial and lateral plateaus on a standard knee MRI. By using this novel measurement technique, a reliable assessment of the medial and lateral tibial plateaus is possible. Level of Evidence: Level III, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidenc

Effects of Noise in a Cortical Neural Model

Recently Segev et al. (Phys. Rev. E 64,2001, Phys.Rev.Let. 88, 2002) made long-term observations of spontaneous activity of in-vitro cortical networks, which differ from predictions of current models in many features. In this paper we generalize the EI cortical model introduced in a previous paper (S.Scarpetta et al. Neural Comput. 14, 2002), including intrinsic white noise and analyzing effects of noise on the spontaneous activity of the nonlinear system, in order to account for the experimental results of Segev et al.. Analytically we can distinguish different regimes of activity, depending from the model parameters. Using analytical results as a guide line, we perform simulations of the nonlinear stochastic model in two different regimes, B and C. The Power Spectrum Density (PSD) of the activity and the Inter-Event-Interval (IEI) distributions are computed, and compared with experimental results. In regime B the network shows stochastic resonance phenomena and noise induces aperiodic collective synchronous oscillations that mimic experimental observations at 0.5 mM Ca concentration. In regime C the model shows spontaneous synchronous periodic activity that mimic activity observed at 1 mM Ca concentration and the PSD shows two peaks at the 1st and 2nd harmonics in agreement with experiments at 1 mM Ca. Moreover (due to intrinsic noise and nonlinear activation function effects) the PSD shows a broad band peak at low frequency. This feature, observed experimentally, does not find explanation in the previous models. Besides we identify parametric changes (namely increase of noise or decreasing of excitatory connections) that reproduces the fading of periodicity found experimentally at long times, and we identify a way to discriminate between those two possible effects measuring experimentally the low frequency PSD.Comment: 25 pages, 10 figures, to appear in Phys. Rev.

Characterizing quantum gases in correlated-disorder realizations using density-density correlations

The role of disorder on physical systems has been widely studied in the macroscopic and microscopic world. While static disorder is well understood in many cases, the impact of time-dependent disorder on quantum gases is still poorly investigated. In our experimental setup, we produce and characterize time-dependent optical-speckle disorder for ultracold quantum gases with tunable correlation time. Experimentally, coherent light illuminates a combination of a static and a rotating diffuser, thereby collecting a spatially varying phase due to the diffusers' structure and a temporally variable phase due to the relative rotation. The rotation speed of the diffuser determines a characteristic time scale of the dynamics. It can be tuned within a broad range matching typical time scales of the quantum gases investigated. We characterize the dynamic speckle pattern ex-situ by measuring its intensity distribution and in-situ by observing its impact on a molecular Bose-Einstein condensate. As one diffuser rotates relative to the other around the common optical axis, we trace the optical speckle's intensity correlations and the quantum gas' density-density correlations. Our results show comparable outcomes for both measurement methods. The setup allows us to tune the disorder potential adapted to the characteristics of the quantum gas. These studies pave the way for investigating nonequilibrium physics in interacting quantum gases using controlled dynamical-disorder potentials.Comment: 12 pages, 8 figure

Ponašanje termički modificiranog drva u vanjskim uvjetima primjene – trajnost, abrazija i izgled

Thermally modified timber (TMT) is increasingly offered in Europe as an alternative to preservative treated timber. TMT durability in field tests as well as its moisture sorption behaviour in façade application was determined so as to consider its suitability for outdoor use. Additionally, abrasion and crack-formation of TMT deckings were examined and the optical appearance of a TMT façade was evaluated after 5 years of service. After 7.5 years exposure in ground contact, the various TMT materials tested were classed as “slightly durable” to “not durable” whereas the classification in above ground exposure was “very durable” to “moderately durable”, which was in line with the reduced moisture sorption of TMT in weathered application. Moreover, the TMT-decking showed less abrasion and crack-formation compared to references, though the TMT façade revealed considerable discoloration by weathering. Hence, the suitability of TMT for above ground use is suggested, but a surface treatment is obligatory if discoloration is objectionable.Termički modificirano drvo (TMT) sve se više nudi u Europi kao alternativa kemijski zaštićenom drvu. Za ocjenu prikladnosti TMT-a za vanjsku upotrebu ispitivana je biološka trajnost u vanjskim uvjetima, kao i sorpcija vode u elementima fasade. Dodatno je ispitivana otpornost na abraziju i nastajanje pukotina u TMT podovima, te je napravljen vizualni pregled TMT fasade nakon petogodišnje upotrebe. Nakon 7,5 godina izloženosti u dodiru s tlom, različiti TMT materijali ocijenjeni su kao "slabo otporni" do "neotporni" dok su ocjene tog istog materijala za izlaganje iznad tla bile "vrlo otporno" do "srednje otporno". Dobivene su ocjene, u skladu sa smanjenom sorpcijom vode TMT materijala u vanjskoj upotrebi. Štoviše, TMT podovi pokazali su manju abraziju i pukotine od referentnog drva, iako su TMT elementi fasade pokazali veću diskoloraciju uzrokovanu abiološkom razgradnjom. Dakle, TMT je u vanjskim uvjetima i iznad tla preporučljiv za upotrebu, ali uz obveznu površinsku obradu ako se želi izbjeći diskoloracija

Performance of thermally modified timber (TMT) in outdoor application - durability, abrasion and optical appearance

Thermally modified timber (TMT) is increasingly offered in Europe as an alternative to preservative treated timber. TMT durability, infield tests as well as its moisture sorption behaviour in facade application was determined so as to consider its suitability for outdoor use. Additionally, abrasion and crack-formation of TMT deckings were examined and the optical appearance of a TMT facade was evaluated after 5 years of service. After 7.5 years exposure in ground contact, the various TMT materials tested were classed as "slightly durable" to "not durable" whereas the classification in above ground exposure was "very durable" to "moderately, durable", which was in line with the reduced moisture sorption of TMT in weathered application. Moreover, the TMT-decking showed less abrasion and crack-formation compared to references, though the TMT facade revealed considerable discoloration by weathering. Hence, the suitability of TMT for above ground use is suggested, but a surface treatment is obligatory if discoloration is objectionable

Enhancing methane production from food waste fermentate using biochar. The added value of electrochemical testing in pre-selecting the most effective type of biochar

Background: Recent studies have suggested that addition of electrically conductive biochar particles is an effective strategy to improve the methanogenic conversion of waste organic substrates, by promoting syntrophic associations between acetogenic and methanogenic organisms based on interspecies electron transfer processes. However, the underlying fundamentals of the process are still largely speculative and, therefore, a priori identification, screening, and even design of suitable biochar materials for a given biotechnological process are not yet possible. Results: Here, three charcoal-like products (i.e., biochars) obtained from the pyrolysis of different lignocellulosic materials, (i.e., wheat bran pellets, coppiced woodlands, and orchard pruning) were tested for their capacity to enhance methane production from a food waste fermentate. In all biochar-supplemented (25 g/L) batch experiments, the complete methanogenic conversion of fermentate volatile fatty acids proceeded at a rate that was up to 5 times higher than that observed in the unamended (or sand-supplemented) controls. Fluorescent in situ hybridization analysis coupled with confocal laser scanning microscopy revealed an intimate association between archaea and bacteria around the biochar particles and provided a clear indication that biochar also shaped the composition of the microbial consortium. Based on the application of a suite of physico-chemical and electrochemical characterization techniques, we demonstrated that the positive effect of biochar is directly related to the electron-donating capacity (EDC) of the material, but is independent of its bulk electrical conductivity and specific surface area. The latter properties were all previously hypothesized to play a major role in the biochar-mediated interspecies electron transfer process in methanogenic consortia. Conclusions: Collectively, these results of this study suggest that for biochar addition in anaerobic digester operation, the screening and identification of the most suitable biochar material should be based on EDC determination, via simple electrochemical tests. © 2017 The Author(s)

Epoxy Resin Nanocomposites: The Influence of Interface Modification on the Dispersion Structure—A Small-Angle-X-ray-Scattering Study

The surface functionalization of inorganic nanoparticles is an important tool for the production of homogeneous nanocomposites. The chemical adaptation of the nano-filler surface can lead to effective weak to strong interactions between the fillers and the organic matrix. Here we present a detailed systematic study of different surface-functionalized particles in combination with a SAXS method for the systematic investigation of the interface interaction in the development of epoxy nanocomposites. We investigated the effect of surface modification of spherical SiO2 nanoparticles with 9 nm and 72 nm diameter and crystalline ZrO2 nanoparticles with 22 nm diameter on the homogeneous distribution of the fillers in diethylenetriamine (DETA) cured bisphenol-F-diglycidylether epoxy resin nanocomposites. Unmodified nanoparticles were compared with surface-modified oxides having diethylene glycol monomethyl ethers (DEG), 1,2-diols, or epoxy groups attached to the surface. The influence of surface modification on dispersion quality was investigated by transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) for inorganic filler contents of 3, 5 and 10 wt%. It was shown that the dispersion quality can be optimized by varying the coupling agent end group to obtain homogeneous and transparent nanomaterials. UV/VIS measurements confirmed the transparency/translucency of the obtained materials. The relationship between particle–matrix interaction and particle–particle interaction plays a decisive role in homogeneity and is controlled by the surface groups as well as by the type, size, and morphology of the nanoparticles themselves

Evaluation des Projekts "Naturnahe Spiel- und Pausenplätze" : Pilotphase 2021 und 2022

Naturnahe Spiel- und Pausenplätze bieten ein grosses Potential für die Förderung einer gesunden Entwicklung von Kindern. Aus diesem Grund unterstützt die Roger Federer Foundation zusammen mit Kooperationspartner:innen die Verbreitung von naturnahen Spiel- und Pausenplätzen an Schweizer Schulen. In einer ersten Pilotphase (2021-2022) erhielten insgesamt 31 Schulen aus der Deutschschweiz und der Romandie unter der Voraussetzung eines sozioökonomisch benachteiligten Umfeld finanzielle und fachliche Unterstützung für die Gestaltung ihres naturnahen Spiel- und Pausenplatzes. Sie wurden bei der Umsetzung, dem partizipativen Prozess und hinsichtlich der pädagogischen Nutzung begleitet und beraten. Mit der vorliegenden Evaluation wurden der Planungs- und Umsetzungsprozess, die in der Pilotphase erarbeiteten Dokumentationen, namentlich ein Planungs- und Gestaltungsdossier und ein pädagogisches Dossier sowie erste Wirkungen des naturnahen Spiel- und Pausenplatzes bewertet. Letztere umfassen die Art und Weise wie die neuen Spiel- und Pausenplätze in den Unterricht und die Betreuung integriert werden und inwiefern sich das Spielverhalten der Schüler:innen aufgrund des neuen Platzes verändert