Inductive reasoning and its underlying structure: Support for difficulty and item position effects

This paper reports an investigation of the influence of method effects on the measurement of reasoning and of the relationships of these effects to basic cognitive processes. For this purpose, the variation due to the item-position and difficulty effects was separated from the variation due to the measured latent source of inductive reasoning. Data were collected by means of inductive reasoning items and cognitive tasks measuring working memory (WM) updating, rule learning, and automatization. Confirmatory factor analysis models served the decomposition of the variation of inductive reasoning data into a purified version of inductive reasoning, item-position, and difficulty components. The investigation of the relationships of corresponding latent variables and basic cognitive processes revealed two major associations: (a) the purified version of reasoning correlated with WM updating and (b) the item-position effect correlated with variants of learning. These results could be interpreted as signifying a two-dimensional structure of reasoning associated with executive functioning and learning processes

La production monétaire romaine en orichalque : caractérisation du monnayage et approche du processus d’élaboration par l’expérimentation

Les monnaies d’orichalque (un alliage de cuivre et de zinc aussi appelé laiton) sont émises de façon systématique sous le principat d’Auguste à partir de 23 av. J.-C. Ce monnayage est composé de sesterces, de dupondii et de semis. Des analyses élémentaires effectuées sur ces monnaies par spectrométrie de fluorescence X, par activation avec des neutrons rapides de cyclotron et par voie humide ont montré que la composition de l’alliage monétaire évolue au cours des émissions : la teneur en zinc diminue. Une des hypothèses émises est que cette baisse serait liée aux refontes successives des monnaies lors de la fabrication de nouvelles émissions.Orichalcum coins (an alloy of copper and zinc also named brass) are systematically issued during the Principate of Augustus from 23 B. C. on. These coins are sesterstii, dupondii and semisses. Elementary analysis of these coins by X-ray Fluorescence spectroscopy, by activation with fast neutrons from a cyclotron and by chemical analysis show an evolution of the alloy composition during the issues: the zinc content decreased. An hypothesis is that this decrease is related to successive meltings of the coins for the elaboration of new issues

Basic approaches to improving resource efficiency in the metals industry

Ohne intensive Nutzung von Metallen wäre die Umsetzung von aktuellen Strategien wie die Realisierung der regenerativen Energiegewinnung oder der Elektromobilität in Deutschland undenkbar. Eine gesicherte Versorgung der Industrie mit allen Primärmetallen kann durch faktische Monopolstrukturen sowie tendenziell sinkenden Erzgehalten nicht als garantiert angesehen werden. Durch eine verbesserte Kreislaufführung kann die Ressourceneffizienz erhöht und die Importabhängigkeit reduziert werden. Damit einhergehende Herausforderungen und mögliche Lösungsansätze werden thematisiert.Without the intensive use of metals, the implementation of current strategies such as the realisation of renewable energy production or electromobility in Germany would be unthinkable. A secure supply of all primary metals to industry cannot be considered guaranteed due to de facto monopoly structures and the trend towards decreasing ore contents. Improved recycling can increase resource efficiency and reduce dependence on imports. The challenges associated with this and possible solutions are discussed

Observation of enhanced chiral asymmetries in the inner-shell photoionization of uniaxially oriented methyloxirane enantiomers

Most large molecules are chiral in their structure: they exist as two enantiomers, which are mirror images of each other. Whereas the rovibronic sublevels of two enantiomers are almost identical, it turns out that the photoelectric effect is sensitive to the absolute configuration of the ionized enantiomer - an effect termed Photoelectron Circular Dichroism (PECD). Our comprehensive study demonstrates that the origin of PECD can be found in the molecular frame electron emission pattern connecting PECD to other fundamental photophysical effects as the circular dichroism in angular distributions (CDAD). Accordingly, orienting a chiral molecule in space enhances the PECD by a factor of about 10

Microengineered Hollow Graphene Tube Systems Generate Conductive Hydrogels with Extremely Low Filler Concentration

The fabrication of electrically conductive hydrogels is challenging as the introduction of an electrically conductive filler often changes mechanical hydrogel matrix properties. Here, we present an approach for the preparation of hydrogel composites with outstanding electrical conductivity at extremely low filler loadings (0.34 S m-1, 0.16 vol %). Exfoliated graphene and polyacrylamide are microengineered to 3D composites such that conductive graphene pathways pervade the hydrogel matrix similar to an artificial nervous system. This makes it possible to combine both the exceptional conductivity of exfoliated graphene and the adaptable mechanical properties of polyacrylamide. The demonstrated approach is highly versatile regarding porosity, filler material, as well as hydrogel system. The important difference to other approaches is that we keep the original properties of the matrix, while ensuring conductivity through graphene-coated microchannels. This novel approach of generating conductive hydrogels is very promising, with particular applications in the fields of bioelectronics and biohybrid robotics

Analysis of hydrogen Rydberg spectra in a uniform magnetic field: uncovering the transition from regularity to irregularity in a real quantum system

Studies of the behaviour of quantum systems in a range of energy where their classical counterparts undergo transitions from regularity to irregularity, as manifested in phase space by the gradual destruction of invariant tori, to date have largely been confined to model Hamiltonian systems such as harmonic oscillators with cubic, quartic, or higher-degree polynomial corrections, or the stadium problem. We show that phenomena which have turned out characteristic of the onset of "quantum stochasticity" in these model systems can in fact be recovered in the quantal energy spectra of a "real" physical system, viz. spectra of hydrogen Rydberg atoms in strong magnetic fields. This implies that one has a simple prototype system at hand in which to study - not only in theory but also in experiment, quantitatively and in detail, and as a function of a continuously tunable external parameter - phenomena that are expected to be typical of the quantum properties of nonintegrable systems in general

Visualization in astrophysics

This paper reports on progress we have made in modelling cosmic X·ray sources on supercomputers. The results we present are meant to serve as an example for the fact that sophisticated visualization techniques play a crucial role in scientific computing. Among the graphical methods we demonstrate, raytracing in curved space-time and a physically motivated 3D-volume rendering algorithm might be of interest to the graphics community in general

TIMolol Nasal Spray as a Treatment for Epistaxis in Hereditary Hemorrhagic Telangiectasia (TIM-HHT)—A Prospective, Randomized, Double-Blind, Controlled, Cross-Over Trial

To date, there is no approved local therapeutic agent for the treatment of epistaxis due to hereditary hemorrhagic telangiectasia (HHT). Several case reports suggest the topical use of timolol. This monocentric, prospective, randomized, placebo-controlled, double-blinded, cross-over study investigated whether the effectiveness of the standard treatment with a pulsed diode laser can be increased by also using timolol nasal spray. The primary outcome was severity of epistaxis after three months, while the main secondary outcome was severity of epistaxis and subjective satisfaction after one month. Twenty patients were allocated and treated, of which 18 patients completed both 3-month treatment sequences. Timolol was well tolerated by all patients. Epistaxis Severity Score after three months, the primary outcome measure, showed a beneficial, but statistically nonsignificant (p = 0.084), effect of additional timolol application. Epistaxis Severity Score (p = 0.010) and patients’ satisfaction with their nosebleeds after one month (p = 0.050) showed statistically significant benefits. This placebo-controlled, randomized trial provides some evidence that timolol nasal spray positively impacts epistaxis severity and subjective satisfaction in HHT patients when additively applied to standard laser therapy after one month. However, the effect of timolol was observed to diminish over time. Trials with larger sample sizes are warranted to confirm these findings