De naaktslak <i>Facelina auriculata</i> (O.F. Müller, 1776) op <i>Eudendrium arbuscula</i> Wright, 1859: nieuwe namen, oude bekenden

The presence of the nudibranch Facelina auriculata (O.F. Müller, 1776) on Eudendrium arbuscula Wright, 1857, in the Oosterschelde (Eastern Scheldt, The Netherlands) is reported. This is the first documented record of E. arbuscula from the Netherlands. The change of name from Facelina coronata (Fornes & Goodsir, 1839) into F. auriculata (O.F. Müller, 1776) is discussed

Extending the functionalities of shear-driven chromatography nano-channels using high aspect ratio etching

An new injection system is presented for shear-driven chromatography. The device has been fabricated by high aspect ratio etching of silicon. The performance of the injection slit is studied through the aid of computational fluid dynamics, and the first experimental results are presented

Depletion-mode Quantum Dots in Intrinsic Silicon

We report the fabrication and electrical characterization of depletion-mode quantum dots in a two-dimensional hole gas (2DHG) in intrinsic silicon. We use fixed charge in a SiO$_2$/Al$_2$O$_3$ dielectric stack to induce a 2DHG at the Si/SiO$_2$ interface. Fabrication of the gate structures is accomplished with a single layer metallization process. Transport spectroscopy reveals regular Coulomb oscillations with charging energies of 10-15 meV and 3-5 meV for the few- and many-hole regimes, respectively. This depletion-mode design avoids complex multilayer architectures requiring precision alignment, and allows to adopt directly best practices already developed for depletion dots in other material systems. We also demonstrate a method to deactivate fixed charge in the SiO$_2$/Al$_2$O$_3$ dielectric stack using deep ultraviolet light, which may become an important procedure to avoid unwanted 2DHG build-up in Si MOS quantum bits.Comment: Accepted to Applied Physics Letters. 5 pages, 3 figure

Long-range forecasting of intermittent streamflow

Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth) of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 6 and 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill

Seeding Change by Visioning Good Anthropocenes

Although we are surrounded by dystopian stories about the age of the Anthropocene, the future does not have to be bleak. Seeds of alternative good futures occur in many places around the world and we can use these to help us think more creatively about pathways to more desirable futures in the Anthropocene. This paper describes the Seeds of Good Anthropocenes (SOGA) project that aims to identify where elements of Good Anthropocenes (‘seeds’) currently exist on the planet and how they can be used to help us envision pathways towards new, positive futures for the Earth and humanity. Each of the seeds is a potential solution that could help to shift us onto a more sustainable trajectory that will ensure both planetary and human wellbeing. The project has developed and combined novel visioning tools that engage a broad set of stakeholders in identifying potentially game-changing seed initiatives, and exploring how these could develop and combine to create radically alternative futures. This new scenario approach has been used in intergovernmental processes such as the UN Environment’s Global Environment Outlook (GEO) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). By tapping into creativity and ingenuity, the SOGA scenario process provides a set of methodological tools through which we can think in new ways about how to navigate towards more desirable futures, starting with the pockets of these futures that are already with us in the present

Structure of the Cytoplasmic Loop between Putative Helices II and III of the Mannitol Permease of Escherichia coli: A Tryptophan and 5-Fluorotryptophan Spectroscopy Study

In this work, four single tryptophan (Trp) mutants of the dimeric mannitol transporter of Escherichia coli, EIImtl, are characterized using Trp and 5-fluoroTrp (5-FTrp) fluorescence spectroscopy. The four positions, 97, 114, 126, and 133, are located in a region shown by recent studies to be involved in the mannitol translocation process. To spectroscopically distinguish between the Trp positions in each subunit of dimeric EIImtl, 5-FTrp was biosynthetically incorporated because of its much simpler photophysics compared to those of Trp. The steady-state and time-resolved fluorescence methodologies used point out that all four positions are in structured environments, both in the absence and in the presence of a saturating concentration of mannitol. The fluorescence decay of all 5-FTrp-containing mutants was highly homogeneous, suggesting similar microenvironments for both probes per dimer. However, Stern-Volmer quenching experiments using potassium iodide indicate different solvent accessibilities for the two probes at positions 97 and 133. A 5 Å two-dimensional (2D) projection map of the membrane-embedded IICmtl dimer showing 2-fold symmetry is available. The results of this work are in better agreement with a 7 Å projection map from a single 2D crystal on which no symmetry was imposed.

Electron and Hole Spin Splitting and Photogalvanic Effect in Quantum Wells

A theory of the circular photogalvanic effect caused by spin splitting in quantum wells is developed. Direct interband transitions between the hole and electron size-quantized subbands are considered. It is shown that the photocurrent value and direction depend strongly on the form of the spin-orbit interaction. The currents induced by structure-, bulk-, and interface-inversion asymmetry are investigated. The photocurrent excitation spectra caused by spin splittings in both conduction and valence bands are calculated.Comment: 7 pages, 3 figure