Dietary variation and overlap in Central and Northwest European Stephanorhinus kirchbergensis and S. hemitoechus (Rhinocerotidae, Mammalia) influenced by habitat diversity

To trace the dietary evolution of the two abundant Middle to Late Pleistocene rhinoceros species Stephanorhinus kirchbergensis and Stephanorhinus hemitoechus in Europe over several climatic cycles, we examined comprehensive material of stratigraphically well-defined alaeopopulations from different regions and interglacials. Using morphometrics and mesowear analysis, these reconstructions of Stephanorhinus diets indicate that habitat diversity and interspecific competition with closely related rhinoceros species induced variation in feeding behaviour. Although anatomical features of both species suggest significantly higher dietary specializations compared to the Early to early Middle Pleistocene Stephanorhinus hundsheimensis, their mesowear signals are characteristic of a mixed feeder diet, similar to that of extant mammal species in relatively open habitats. Both species retained a degree of dietary flexibility, enabling them to survive in a range of environments. Although each of these rhinoceroses preferred different habitats, species identity alone is not sufficient to establish the real dietary traits of a Stephanorhinus palaeopopulation. As a consequence, their occurrence in a faunal assemblage alone cannot be taken to indicate a specific habitat. S. kirchbergensis and S. hemitoechus were embedded in a dynamic process of temporo-spatial replacements and interspecific differentiation of rhinoceroses in the western Palaearctic. However, dietary specialization in these Middle to Late Pleistocene European rhinoceroses was not the result of a directed time-transgressive evolution. Rather, within the range of each species' ecological tolerance, it was controlled by environmental parameters, with habitat variability as the main factor

High-Field Superconductivity at an Electronic Topological Transition in URhGe

The emergence of superconductivity at high magnetic fields in URhGe is regarded as a paradigm for new state formation approaching a quantum critical point. Until now, a divergence of the quasiparticle mass at the metamagnetic transition was considered essential for superconductivity to survive at magnetic fields above 30 tesla. Here we report the observation of quantum oscillations in URhGe revealing a tiny pocket of heavy quasiparticles that shrinks continuously with increasing magnetic field, and finally disappears at a topological Fermi surface transition close to or at the metamagnetic field. The quasiparticle mass decreases and remains finite, implying that the Fermi velocity vanishes due to the collapse of the Fermi wavevector. This offers a novel explanation for the re-emergence of superconductivity at extreme magnetic fields and makes URhGe the first proven example of a material where magnetic field-tuning of the Fermi surface, rather than quantum criticality alone, governs quantum phase formation.Comment: A revised version has been accepted for publication in Nature Physic

Lagrangian Reachabililty

We introduce LRT, a new Lagrangian-based ReachTube computation algorithm that conservatively approximates the set of reachable states of a nonlinear dynamical system. LRT makes use of the Cauchy-Green stretching factor (SF), which is derived from an over-approximation of the gradient of the solution flows. The SF measures the discrepancy between two states propagated by the system solution from two initial states lying in a well-defined region, thereby allowing LRT to compute a reachtube with a ball-overestimate in a metric where the computed enclosure is as tight as possible. To evaluate its performance, we implemented a prototype of LRT in C++/Matlab, and ran it on a set of well-established benchmarks. Our results show that LRT compares very favorably with respect to the CAPD and Flow* tools.Comment: Accepted to CAV 201

What is Quantum? Unifying Its Micro-Physical and Structural Appearance

We can recognize two modes in which 'quantum appears' in macro domains: (i) a 'micro-physical appearance', where quantum laws are assumed to be universal and they are transferred from the micro to the macro level if suitable 'quantum coherence' conditions (e.g., very low temperatures) are realized, (ii) a 'structural appearance', where no hypothesis is made on the validity of quantum laws at a micro level, while genuine quantum aspects are detected at a structural-modeling level. In this paper, we inquire into the connections between the two appearances. We put forward the explanatory hypothesis that, 'the appearance of quantum in both cases' is due to 'the existence of a specific form of organisation, which has the capacity to cope with random perturbations that would destroy this organisation when not coped with'. We analyse how 'organisation of matter', 'organisation of life', and 'organisation of culture', play this role each in their specific domain of application, point out the importance of evolution in this respect, and put forward how our analysis sheds new light on 'what quantum is'.Comment: 10 page

"Optical conductance fluctuations: diagrammatic analysis in Landauer approach and non-universal effects"

The optical conductance of a multiple scattering medium is the total transmitted light of a diffuse incoming beam. This quantity, very analogous to the electronic conductance, exhibits universal conductance fluctuations. We perform a detailed diagrammatic analysis of these fluctuations. With a Kadanoff-Baym technique all the leading diagrams are systematically generated. A cancellation of the short distance divergencies occurs, that yields a well behaved theory. The analytical form of the fluctuations is calculated and applied to optical systems. Absorption and internal reflections reduce the fluctuations significantly.Comment: 25 pages Revtex 3.0, 18 seperate postscript figure

Cross validation of bi-modal health-related stress assessment

This study explores the feasibility of objective and ubiquitous stress assessment. 25 post-traumatic stress disorder patients participated in a controlled storytelling (ST) study and an ecologically valid reliving (RL) study. The two studies were meant to represent an early and a late therapy session, and each consisted of a "happy" and a "stress triggering" part. Two instruments were chosen to assess the stress level of the patients at various point in time during therapy: (i) speech, used as an objective and ubiquitous stress indicator and (ii) the subjective unit of distress (SUD), a clinically validated Likert scale. In total, 13 statistical parameters were derived from each of five speech features: amplitude, zero-crossings, power, high-frequency power, and pitch. To model the emotional state of the patients, 28 parameters were selected from this set by means of a linear regression model and, subsequently, compressed into 11 principal components. The SUD and speech model were cross-validated, using 3 machine learning algorithms. Between 90% (2 SUD levels) and 39% (10 SUD levels) correct classification was achieved. The two sessions could be discriminated in 89% (for ST) and 77% (for RL) of the cases. This report fills a gap between laboratory and clinical studies, and its results emphasize the usefulness of Computer Aided Diagnostics (CAD) for mental health care

Coulomb excitation of 68^{68}Ni at safe energies

The $B(E2;0^+\to2^+)$ value in $^{68}$Ni has been measured using Coulomb excitation at safe energies. The $^{68}$Ni radioactive beam was post-accelerated at the ISOLDE facility (CERN) to 2.9 MeV/u. The emitted $\gamma$ rays were detected by the MINIBALL detector array. A kinematic particle reconstruction was performed in order to increase the measured c.m. angular range of the excitation cross section. The obtained value of 2.8$^{+1.2}_{-1.0}$ 10$^2$ e$^2$fm$^4$ is in good agreement with the value measured at intermediate energy Coulomb excitation, confirming the low $0^+\to2^+$ transition probability.Comment: 4 pages, 5 figure

R-process enrichment from a single event in an ancient dwarf galaxy

Elements heavier than zinc are synthesized through the (r)apid and (s)low neutron-capture processes. The main site of production of the r-process elements (such as europium) has been debated for nearly 60 years. Initial studies of chemical abundance trends in old Milky Way halo stars suggested continual r-process production, in sites like core-collapse supernovae. But evidence from the local Universe favors r-process production mainly during rare events, such as neutron star mergers. The appearance of a europium abundance plateau in some dwarf spheroidal galaxies has been suggested as evidence for rare r-process enrichment in the early Universe, but only under the assumption of no gas accretion into the dwarf galaxies. Cosmologically motivated gas accretion favors continual r-process enrichment in these systems. Furthermore, the universal r-process pattern has not been cleanly identified in dwarf spheroidals. The smaller, chemically simpler, and more ancient ultra-faint dwarf galaxies assembled shortly after the first stars formed, and are ideal systems with which to study nucleosynthesis events such as the r-process. Reticulum II is one such galaxy. The abundances of non-neutron-capture elements in this galaxy (and others like it) are similar to those of other old stars. Here, we report that seven of nine stars in Reticulum II observed with high-resolution spectroscopy show strong enhancements in heavy neutron-capture elements, with abundances that follow the universal r-process pattern above barium. The enhancement in this "r-process galaxy" is 2-3 orders of magnitude higher than that detected in any other ultra-faint dwarf galaxy. This implies that a single rare event produced the r-process material in Reticulum II. The r-process yield and event rate are incompatible with ordinary core-collapse supernovae, but consistent with other possible sites, such as neutron star mergers.Comment: Published in Nature, 21 Mar 2016: http://dx.doi.org/10.1038/nature1742

Evaluating strategic environmental assessment in the Netherlands: Content, process and procedure as indissoluble criteria for effectiveness

To assess the effectiveness of strategic environmental assessment (SEA) we distinguish between its contribution to the quality of the ultimate policy choice (usefulness, applicability), the procedural quality of the planning process (transparency, timeliness) and the quality of stakeholder participation in the planning process (openness, equity, dialogue). In the context of two case studies involving Dutch planning practice, we argue that when and how an SEA is applied is crucial to understanding its e

Periodic revisions of the international choices criteria: Process and results

Unhealthy diets contribute to an increased risk of non-communicable diseases, which are the leading causes of deaths worldwide. Nutrition policies such as front-of-pack labeling have been developed and implemented globally in different countries to stimulate healthier diets. The Choices Programme, including the International Choices criteria, is an established tool to support the implementation of such policies. The Choices criteria were developed to define the healthier choices per product group, taking saturated fatty acids, trans fatty acids, sodium, sugars, energy, and fiber into account. To keep these criteria updated, they are periodically revised by an independent international scientific committee. This paper explains the most important changes resulting from revisions between 2010 and 2016 and describes the process of the latest revision, resulting in the International Choices criteria version 2019. Revisions were based on national and international nutrition and dietary recommendations, large food composition databases, and stakeholders’ feedback. Other nutrient profiling systems served as benchmarks. The product group classification was adapted and new criteria were determined in order to enhance global applicability and form a credible, intuitively logical system for users. These newly developed criteria will serve as an international standard for healthier products and provide a guiding framework for food and nutrition policies. © 2020 by the authors. Licensee MDPI, Basel, Switzerland