Selective auditory grouping by zebra finches: testing the iambic–trochaic law

Animal science

Characteristics and challenges of the modern Belgian veal industry

In this paper, the modern Belgian veal industry is situated in a European context, and an overview is provided of the major past, present and future challenges for veal production. The production of white veal requires a specific diet and housing conditions to assure a controlled iron anemic state resulting in pale carcasses. In response to the increasing public concern about animal welfare, legal limits for hemoglobin (in 1990), the provision of a minimum quality of solid feed to assure ruminal health and group housing from the age of eight weeks on (in 2007), have been implemented sector-wide. The integrated structure of the sector likely made it possible to realize these radical changes at relatively short notice. Despite the pioneers role the veal industry played in the development of quality labels for food safety and all efforts made towards improved nutrition and housing, the veal production remains highly liable to public criticism on welfare issues. Nowadays, especially the intensive antimicrobial use in relation to high levels of antimicrobial resistance in commensal, pathogenic and zoonotic bacteria in veal calves is strongly criticized. The future challenge lies in the development of veal production systems, which require only few antibiotics, but safeguard animal welfare and revenue

Aharonov-Bohm effect in graphene

We investigate experimentally transport through ring-shaped devices etched in graphene and observe clear Aharonov-Bohm conductance oscillations. The temperature dependence of the oscillation amplitude indicates that below 1 K the phase coherence length is comparable to or larger than the size of the ring. An increase in the amplitude is observed at high magnetic field, when the cyclotron diameter becomes comparable to the width of the arms of the ring. By measuring the dependence on gate voltage, we also observe an unexpected linear dependence of the oscillation amplitude on the ring conductance, which had not been reported earlier in rings made using conventional metals or semiconducting heterostructures.Comment: 14 pages, 5 figure

Gut microbiome studies in CKD: opportunities, pitfalls and therapeutic potential

Interest in gut microbiome dysbiosis and its potential association with the development and progression of chronic kidney disease (CKD) has increased substantially in the past 6 years. In parallel, the microbiome field has matured considerably as the importance of host-related and environmental factors is increasingly recognized. Past research output in the context of CKD insufficiently considered the myriad confounding factors that are characteristic of the disease. Gut microbiota-derived metabolites remain an interesting therapeutic target to decrease uraemic (cardio)toxicity. However, future studies on the effect of dietary and biotic interventions will require harmonization of relevant readouts to enable an in-depth understanding of the underlying beneficial mechanisms. High-quality standards throughout the entire microbiome analysis workflow are also of utmost importance to obtain reliable and reproducible results. Importantly, investigating the relative composition and abundance of gut bacteria, and their potential association with plasma uraemic toxins levels is not sufficient. As in other fields, the time has come to move towards in-depth quantitative and functional exploration of the patient’s gut microbiome by relying on confounder-controlled quantitative microbial profiling, shotgun metagenomics and in vitro simulations of microorganism–microorganism and host–microorganism interactions. This step is crucial to enable the rational selection and monitoring of dietary and biotic intervention strategies that can be deployed as a personalized intervention in CKD

Bipolar supercurrent in graphene

Graphene -a recently discovered one-atom-thick layer of graphite- constitutes a new model system in condensed matter physics, because it is the first material in which charge carriers behave as massless chiral relativistic particles. The anomalous quantization of the Hall conductance, which is now understood theoretically, is one of the experimental signatures of the peculiar transport properties of relativistic electrons in graphene. Other unusual phenomena, like the finite conductivity of order 4e^2/h at the charge neutrality (or Dirac) point, have come as a surprise and remain to be explained. Here, we study the Josephson effect in graphene. Our experiments rely on mesoscopic superconducting junctions consisting of a graphene layer contacted by two closely spaced superconducting electrodes, where the charge density can be controlled by means of a gate electrode. We observe a supercurrent that, depending on the gate voltage, is carried by either electrons in the conduction band or by holes in the valence band. More importantly, we find that not only the normal state conductance of graphene is finite, but also a finite supercurrent can flow at zero charge density. Our observations shed light on the special role of time reversal symmetry in graphene and constitute the first demonstration of phase coherent electronic transport at the Dirac point.Comment: Under review, 12 pages, 4 Figs., suppl. info (v2 identical, resolved file problems

The FDR4ATMOS Project

The FDR4ATMOS project has two main tasks. The focus of task A is to update the SCIAMACHY processing chain for better Ozone total columns. After the full re-processing of the SCIAMACHY mission with processor versions 9 (Level 1) and version 7 (Level 2), the comparison with ground-based data showed that the total Ozone column showed a downward trend of nearly 2% from the beginning of the time series to its end. This trend is an artefact and is likely caused by changes made to the calibration algorithms in the Level 1 processor (the DOAS retrieval algorithm for Ozone was not changed). The most likely reason are changes in the degradation correction that lead to subtle changes in the spectral structures that in the retrieval are interpreted as an atmospheric signature. In task A we will update the Level 0-1 processor with the final aim of a mission re-processing. The second task in the FDR4ATMOS project is to develop a cross-instrument Level 1 product for GOME-1 and SCIAMACHY for the UV, VIS and NIR spectral range with a focus on the spectral windows used for O3, SO2, NO2 total column retrieval and the determination of cloud properties. Contrary to other projects, FDR4ATMOS does not aim to build a harmonised time series on Level 2 products but on Level 1 products, i.e. radiances and reflectances. The GOME-1 and SCIAMACHY instrument together span 17 years of spectrally highly resolved data. The goal of the FDR4ATMOS project is to generate harmonised data sets that allow the user to use it directly in long term trend analysis, independent of the instrument. Since this was never done for highly resolved spectrometers, new methods have to be developed that e.g. take into account the different observation geometries and observation times of the instrument without impacting the spectral structures that are used for the retrieval of the atmospheric species. The resulting algorithms and the processor should also be as generic as possible to be able to transfer the methodology easily to other instruments (e.g. GOME-2, Sentinel-5p) for a future extension of the time series. The FDR4ATMOS started in October 2019 and is currently in phase 1. We will present the goals of the project and first results

Synthetic MRI demonstrates prolonged regional relaxation times in the brain of preterm born neonates with severe postnatal morbidity

Background: To identify preterm infants at risk for neurodevelopment impairment that might benefit from early neurorehabilitation, early prognostic biomarkers of future outcomes are needed. Objective: To determine whether synthetic MRI is sensitive to age-related changes in regional tissue relaxation times in the brain of preterm born neonates when scanned at term equivalent age (TEA, 37–42 weeks), and to investigate whether severe postnatal morbidity results in prolonged regional tissue relaxation times. Materials and methods: This retrospective study included 70 very preterm born infants scanned with conventional and synthetic MRI between January 2017 and June 2019 at TEA. Infants with severe postnatal morbidity were allocated to a high-risk group (n = 22). All other neonates were allocated to a low-risk group (n = 48). Linear regression analysis was performed to determine the relationship between relaxation times and postmenstrual age (PMA) at scan. Analysis of covariance was used to evaluate the impact of severe postnatal morbidity in the high-risk group on T1 and T2 relaxation times. Receiver operating characteristic (ROC) curves were plotted and analysed with area under the ROC curve (AUC) to evaluate the accuracy of classifying high-risk patients based on regional relaxation times. Results: A linear age-related decrease of T1 and T2 relaxation times correlating with PMA at scan (between 37 and 42 weeks) was found in the deep gray matter, the cerebellum, the cortex, and the posterior limb of the internal capsule (PLIC) (p < .005 each), but not in the global, frontal, parietal, or central white matter. Analysis of covariance for both risk groups, adjusted for PMA, revealed significantly prolonged regional tissue relaxation times in neonates with severe postnatal morbidity, which was best illustrated in the central white matter of the centrum semiovale (T1 Δ = 11.5%, T2 Δ = 13.4%, p < .001) and in the PLIC (T1 Δ = 9.2%, T2 Δ = 6.9%, p < .001). The relaxation times in the PLIC and the central white matter predicted high-risk status with excellent accuracy (AUC range 0.82–0.86). Conclusion: Synthetic MRI-based relaxometry in the brain of preterm born neonates is sensitive to age-related maturational changes close to TEA. Severe postnatal morbidity correlated with a significant delay in tissue relaxation. Synthetic MRI may provide early prognostic biomarkers for neurodevelopment impairment