First Steps in the Development of a Wheat Flour Based Lactic Acid Fermentation Technology. Culture Medium Optimization

Batch fermentation experiments were performed to evaluate the potentials of different fractions of wheat as alternative carbon and nitrogen source for an economical production of lactic acid by a homofermentative mesophilic bacterium (Lactobacillus sp. MKT-878 NCAIM B02375). Hydrolysing the starch content of wheat results in well consumable glucose solution, and simultaneously by hydrolysing the insoluble protein content (gluten) of wheat the nitrogen source can be assured as well. The necessary yeast extract concentration was 30 g L–1 on hydrolysed wheat starch solution without gluten fraction. By means of an optimization process we found that the gluten fraction can substitute the major part of the added yeast extract as nitrogen source, and on the basis of a statistical experimental design we created an optimized medium with 8 g L–1 yeast extract and 16 g L–1 gluten supplementation, resulting in 3.54 g L–1h–1 productivity which can be considered as an industrially acceptable process output

Many-body position operator in lattice fermionic systems with periodic boundary conditions

A total position operator $X$ in the position representation is derived for lattice fermionic systems with periodic boundary conditions. The operator is shown to be Hermitian, the generator of translations in momentum space, and its time derivative is shown to correspond to the total current operator in a periodic system. The operator is such that its moments can be calculated up to any order. To demonstrate its utility finite size scaling is applied to the Brinkman-Rice transition as well as metallic and insulating Gutzwiller wavefunctions.Comment: to appear in Journal of Physics A: Mathematical and General (reference will be added later

Making seismology accessible to the public in Nepal: an earthquake location tutorial for education purposes

Earthquakes become a hot topic for discussion in Nepali communities when a big local event happens. Beyond the seismic monitoring and research, efforts to improve the population’s preparedness or to reduce earthquake related risks are limited, and there is a gap between scientific community and society. To establish the missing link between seismology and citizens we have initiated an educational approach called Seismology at School in Nepal and a total of 30 low-cost seismometers have been installed in schools. The program is engaging the public on earthquake related activities and found to be effective in raising the awareness levels of children, promoting broader earthquake learning in the community, thus improving the adaptive capacities and preparedness for future earthquakes. The aim of this work is to present a simple tutorial of earthquake location mainly for Nepali citizens and school teachers. We describe procedures for computing an earthquake epicenter using an open and user-friendly software, Seisgram2K. This tutorial helps the public to have first-order information on earthquakes, by allowing to locate epicenters, which will increase the frequency of earthquake discussion in the community. Open seismic data and the earthquake location tutorial helps to inspire the next generation to study Earth sciences, which is very important and required for earthquake prone countries, like Nepal

Segmentation of the Himalayas as revealed by arc-parallel gravity anomalies

International audienceLateral variations along the Himalayan arc are suggested by an increasing number of studies and carry important information about the orogen’s segmentation. Here we compile the hitherto most complete land gravity dataset in the region which enables the currently highest resolution plausible analysis. To study lateral variations in collisional structure we compute arc-parallel gravity anomalies (APaGA) by subtracting the average arc-perpendicular profile from our dataset; we compute likewise for topography (APaTA). We find no direct correlation between APaGA, APaTA and background seismicity, as suggested in oceanic subduction context. In the Himalayas APaTA mainly reflect relief and erosional effects, whereas APaGA reflect the deep structure of the orogen with clear lateral boundaries. Four segments are outlined and have disparate flexural geometry: NE India, Bhutan, Nepal & India until Dehradun, and NW India. The segment boundaries in the India plate are related to inherited structures, and the boundaries of the Shillong block are highlighted by seismic activity. We find that large earthquakes of the past millennium do not propagate across the segment boundaries defined by APaGA, therefore these seem to set limits for potential rupture of megathrust earthquakes

Strong spin-orbit interaction and gg-factor renormalization of hole spins in Ge/Si nanowire quantum dots

The spin-orbit interaction lies at the heart of quantum computation with spin qubits, research on topologically non-trivial states, and various applications in spintronics. Hole spins in Ge/Si core/shell nanowires experience a spin-orbit interaction that has been predicted to be both strong and electrically tunable, making them a particularly promising platform for research in these fields. We experimentally determine the strength of spin-orbit interaction of hole spins confined to a double quantum dot in a Ge/Si nanowire by measuring spin-mixing transitions inside a regime of spin-blockaded transport. We find a remarkably short spin-orbit length of $\sim$65 nm, comparable to the quantum dot length and the interdot distance. We additionally observe a large orbital effect of the applied magnetic field on the hole states, resulting in a large magnetic field dependence of the spin-mixing transition energies. Strikingly, together with these orbital effects, the strong spin-orbit interaction causes a significant enhancement of the $g$-factor with magnetic field.The large spin-orbit interaction strength demonstrated is consistent with the predicted direct Rashba spin-orbit interaction in this material system and is expected to enable ultrafast Rabi oscillations of spin qubits and efficient qubit-qubit interactions, as well as provide a platform suitable for studying Majorana zero modes

Geosciences Roadmap for Research Infrastructures 2025–2028 by the Swiss Geosciences Community

This community roadmap presents an integrative approach including the most urgent infrastructure requests for the future development of geosciences in Switzerland. It recommends to strengthen the multidisciplinary nature of the geosciences by putting all activities under the roof of the Integrated Swiss Geosciences supported by four specific research infrastructure pillars. The roadmap represents the view of the Swiss scientific community in the field of geosciences and is a formal element of the process to elaborate the Swiss Roadmap for Research Infrastructures 2023. This bottom-up contribution to the identification and selection of important national and international research infrastructures has been coordinated by the Swiss Academy of Sciences (SCNAT) on a mandate by the State Secretariat for Education, Research and Innovation (SERI).ISSN:2297-1564ISSN:2297-157

Ab initio van der Waals interactions in simulations of water alter structure from mainly tetrahedral to high-density-like

The structure of liquid water at ambient conditions is studied in ab initio molecular dynamics simulations using van der Waals (vdW) density-functional theory, i.e. using the new exchange-correlation functionals optPBE-vdW and vdW-DF2. Inclusion of the more isotropic vdW interactions counteracts highly directional hydrogen-bonds, which are enhanced by standard functionals. This brings about a softening of the microscopic structure of water, as seen from the broadening of angular distribution functions and, in particular, from the much lower and broader first peak in the oxygen-oxygen pair-correlation function (PCF), indicating loss of structure in the outer solvation shells. In combination with softer non-local correlation terms, as in the new parameterization of vdW-DF, inclusion of vdW interactions is shown to shift the balance of resulting structures from open tetrahedral to more close-packed. The resulting O-O PCF shows some resemblance with experiment for high-density water (A. K. Soper and M. A. Ricci, Phys. Rev. Lett., 84:2881, 2000), but not directly with experiment for ambient water. However, an O-O PCF consisting of a linear combination of 70% from vdW-DF2 and 30% from experiment on low-density liquid water reproduces near-quantitatively the experimental O-O PCF for ambient water, indicating consistency with a two-liquid model with fluctuations between high- and low-density regions

Moho depths beneath the European Alps: a homogeneously processed map and receiver functions database

We use seismic waveform data from the AlpArray Seismic Network and three other temporary seismic networks, to perform receiver function (RF) calculations and time-to-depth migration to update the knowledge of the Moho discontinuity beneath the broader European Alps. In particular, we set up a homogeneous processing scheme to compute RFs using the time-domain iterative deconvolution method and apply consistent quality control to yield 112 205 high-quality RFs. We then perform time-to-depth migration in a newly implemented 3D spherical coordinate system using a European-scale reference P and S wave velocity model. This approach, together with the dense data coverage, provide us with a 3D migrated volume, from which we present migrated profiles that reflect the first-order crustal thickness structure. We create a detailed Moho map by manually picking the discontinuity in a set of orthogonal profiles covering the entire area. We make the RF dataset, the software for the entire processing workflow, as well as the Moho map, openly available; these open-access datasets and results will allow other researchers to build on the current study.</p