Short-term changes in particulate fluxes measured by drifting sediment traps during end summer oligotrophic regime in the NW Mediterranean Sea

Short-term changes in the flux of particulate matter were determined in the central north western Mediterranean Sea (near DYFAMED site) using drifting sediment traps at 200 m depth in the course of the DYNAPROC 2 cruise (14 September–17 October 2004). In this period of marked water column stratification, POC fluxes varied by an order of magnitude, in the range of 0.03–0.29 mgC m<sup>−2</sup> h<sup>−1</sup> over the month and showed very rapid and high variations. Particulate carbon export represented less than 5% of integrated primary production, suggesting that phytoplankton production was essentially sustained by internal recycling of organic matter and retained within the photic zone. While PON and POP fluxes paralleled one another, the elemental ratios POC/PON and POC/POP, varied widely over short-term periods. Values of these ratios generally higher than the conventional Redfield ratio, together with the very low chlorophyll a flux recorded in the traps (mean 0.017 μg m<sup>−2</sup> h<sup>−1</sup>), and the high phaeopigment and acyl lipid hydrolysis metabolite concentrations of the settling material, indicated that the organic matter reaching 200 m depth was reworked (by grazing, fecal pellets production, degradation) and that algal sinking, dominated by nano- and picoplankton, made a small contribution to the downward flux. Over time, the relative abundance of individual lipid classes in organic matter (OM) changed from glycolipids-dominated to neutral (wax esters, triacylglycerols) and phospholipids-dominated, suggesting ecosystem maturation as well as rapid and continual exchanges between dissolved, suspended and sinking pools. Our most striking result was documenting the rapid change in fluxes of the various measured parameters. In the situation encountered here, with dominant regenerated production, a decrease of fluxes was noticed during windy periods (possibly through reduction of grazing). But fluxes increased as soon as calm conditions settle

Simulating Root Growth as a Function of Soil Strength and Yield With a Field-Scale Crop Model Coupled With a 3D Architectural Root Model

Accurate prediction of root growth and related resource uptake is crucial to accurately simulate crop growth especially under unfavorable environmental conditions. We coupled a 1D field-scale crop-soil model running in the SIMPLACE modeling framework with the 3D architectural root model CRootbox on a daily time step and implemented a stress function to simulate root elongation as a function of soil bulk density and matric potential. The model was tested with field data collected during two growing seasons of spring barley and winter wheat on Haplic Luvisol. In that experiment, mechanical strip-wise subsoil loosening (30–60 cm) (DL treatment) was tested, and effects on root and shoot growth at the melioration strip as well as in a control treatment were evaluated. At most soil depths, strip-wise deep loosening significantly enhanced observed root length densities (RLDs) of both crops as compared to the control. However, the enhanced root growth had a beneficial effect on crop productivity only in the very dry season in 2018 for spring barley where the observed grain yield at the strip was 18% higher as compared to the control. To understand the underlying processes that led to these yield effects, we simulated spring barley and winter wheat root and shoot growth using the described field data and the model. For comparison, we simulated the scenarios with the simpler 1D conceptual root model. The coupled model showed the ability to simulate the main effects of strip-wise subsoil loosening on root and shoot growth. It was able to simulate the adaptive plasticity of roots to local soil conditions (more and thinner roots in case of dry and loose soil). Additional scenario runs with varying weather conditions were simulated to evaluate the impact of deep loosening on yield under different conditions. The scenarios revealed that higher spring barley yields in DL than in the control occurred in about 50% of the growing seasons. This effect was more pronounced for spring barley than for winter wheat. Different virtual root phenotypes were tested to assess the potential of the coupled model to simulate the effect of varying root traits under different conditions.Peer Reviewe

Project 8 Phase III Design Concept

We present a working concept for Phase III of the Project 8 experiment, aiming to achieve a neutrino mass sensitivity of $2~\mathrm{eV}$ ($90~\%$ C.L.) using a large volume of molecular tritium and a phased antenna array. The detection system is discussed in detail.Comment: 3 pages, 3 figures, Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

Results from the Project 8 phase-1 cyclotron radiation emission spectroscopy detector

The Project 8 collaboration seeks to measure the absolute neutrino mass scale by means of precision spectroscopy of the beta decay of tritium. Our technique, cyclotron radiation emission spectroscopy, measures the frequency of the radiation emitted by electrons produced by decays in an ambient magnetic field. Because the cyclotron frequency is inversely proportional to the electron's Lorentz factor, this is also a measurement of the electron's energy. In order to demonstrate the viability of this technique, we have assembled and successfully operated a prototype system, which uses a rectangular waveguide to collect the cyclotron radiation from internal conversion electrons emitted from a gaseous $^{83m}$Kr source. Here we present the main design aspects of the first phase prototype, which was operated during parts of 2014 and 2015. We will also discuss the procedures used to analyze these data, along with the features which have been observed and the performance achieved to date.Comment: 3 pages; 2 figures; Proceedings of Neutrino 2016, XXVII International Conference on Neutrino Physics and Astrophysics, 4-9 July 2016, London, U

Complete lung agenesis caused by complex genomic rearrangements with neo-TAD formation at the SHH locus

During human organogenesis, lung development is a timely and tightly regulated developmental process under the control of a large number of signaling molecules. Understanding how genetic variants can disturb normal lung development causing different lung malformations is a major goal for dissecting molecular mechanisms during embryogenesis. Here, through exome sequencing (ES), array CGH, genome sequencing (GS) and Hi-C, we aimed at elucidating the molecular basis of bilateral isolated lung agenesis in three fetuses born to a non-consanguineous family. We detected a complex genomic rearrangement containing duplicated, triplicated and deleted fragments involving the SHH locus in fetuses presenting complete agenesis of both lungs and near-complete agenesis of the trachea, diagnosed by ultrasound screening and confirmed at autopsy following termination. The rearrangement did not include SHH itself, but several regulatory elements for lung development, such as MACS1, a major SHH lung enhancer, and the neighboring genes MNX1 and NOM1. The rearrangement incorporated parts of two topologically associating domains (TADs) including their boundaries. Hi-C of cells from one of the affected fetuses showed the formation of two novel TADs each containing SHH enhancers and the MNX1 and NOM1 genes. Hi-C together with GS indicate that the new 3D conformation is likely causative for this condition by an inappropriate activation of MNX1 included in the neo-TADs by MACS1 enhancer, further highlighting the importance of the 3D chromatin conformation in human disease

Locust: C++ software for simulation of RF detection

The Locust simulation package is a newC++software tool developed to simulate the measurement of time-varying electromagnetic fields using RF detection techniques. Modularity and flexibility allow for arbitrary input signals, while concurrently supporting tight integration with physics-based simulations as input. External signals driven by the Kassiopeia particle tracking package are discussed, demonstrating conditional feedback between Locust and Kassiopeia during software execution. An application of the simulation to the Project8 experiment is described