Nanowire Transistors with Bound-Charge Engineering.

Low-dimensional electronic systems such as silicon nanowires exhibit weak screening which is detrimental to the performance and scalability of nanodevices, e.g., tunnel field-effect transistors.

Revealing Plasma Membrane Nano-Domains with Diffusion Analysis Methods.

Nano-domains are sub-light-diffraction-sized heterogeneous areas in the plasma membrane of cells, which are involved in cell signalling and membrane trafficking. Throughout the last thirty years, these nano-domains have been researched extensively and have been the subject of multiple theories and models: the lipid raft theory, the fence model, and the protein oligomerization theory. Strong evidence exists for all of these, and consequently they were combined into a hierarchal model.

Ab Initio Calculations of Low-Energy Nuclear Scattering Using Confining Potential Traps.

A recently modified method to enable low-energy nuclear scattering results to be extracted from the discrete energy levels of the target-projectile clusters confined by harmonic potential traps is tested. We report encouraging results for neutron-α and neutron-^{24}O elastic scattering from analyzing the trapped levels computed using two different ab initio nuclear structure methods. The n-α results have also been checked against a direct ab initio reaction calculation.

Kinetic roughening of the urban skyline.

We analyze the morphology of the modern urban skyline in terms of its roughness properties. This is facilitated by a database of 10^{7} building heights in cities throughout the Netherlands which allows us to compute the asymptotic height difference correlation function in each city. We find that in cities for which the height correlations display power-law scaling as a function of distance between the buildings, the corresponding roughness exponents are commensurate to the Edwards-Wilkinson and Kardar-Parisi-Zhang equations for kinetic roughening.

Probing relationships between reinforcement learning and simple behavioral strategies to understand probabilistic reward learning.

Background: Reinforcement learning (RL) and win stay/lose shift model accounts of decision making are both widely used to describe how individuals learn about and interact with rewarding environments. Though mutually informative, these accounts are often conceptualized as independent processes and so the potential relationships between win stay/lose shift tendencies and RL parameters have not been explored.

New Method: We introduce a methodology to directly relate RL parameters to behavioral strategy.

Spin-polarized quantum transport in Si dangling bond wires.

We report theoretical modeling of spin-dependent quantum transport properties of dangling bond wires (DBWs) on the Si(100)-2 × 1:H surface. A single spin-polarized dangling bond center (DBC) near the DBW may strongly affect transport as characterized by anti-resonances or dips in the transmission spectra. Such spin-dependent gating can be effective up to a distance of 1.

An apparatus based on an atomic force microscope for implementing tip-controlled local breakdown.

Solid-state nanopores are powerful tools for sensing of single biomolecules in solution. Fabrication of solid-state nanopores is still challenging, however; in particular, new methods are needed to facilitate the integration of pores with larger nanofluidic and electronic device architectures. We have developed the tip-controlled local breakdown (TCLB) approach, in which an atomic force microscope (AFM) tip is brought into contact with a silicon nitride membrane that is placed onto an electrolyte reservoir.

Detection of CMB-Cluster Lensing using Polarization Data from SPTpol.

We report the first detection of gravitational lensing due to galaxy clusters using only the polarization of the cosmic microwave background (CMB). The lensing signal is obtained using a new estimator that extracts the lensing dipole signature from stacked images formed by rotating the cluster-centered Stokes QU map cutouts along the direction of the locally measured background CMB polarization gradient. Using data from the SPTpol 500  deg^{2} survey at the locations of roughly 18 000 clusters with richness λ≥10 from the Dark Energy Survey (DES) Year-3 full galaxy cluster catalog, we detect lensing at 4.

The C-Band All-Sky Survey (C-BASS): Simulated parametric fitting in single pixels in total intensity and polarization.

The cosmic microwave background (CMB) -mode signal is potentially weaker than the diffuse Galactic foregrounds over most of the sky at any frequency. A common method of separating the CMB from these foregrounds is via pixel-based parametric-model fitting. There are not currently enough all-sky maps to fit anything more than the most simple models of the sky.

Successive Kinesin-5 Microtubule Crosslinking and Sliding Promote Fast, Irreversible Formation of a Stereotyped Bipolar Spindle.

Separation of duplicated spindle poles is the first step in forming the mitotic spindle. Kinesin-5 crosslinks and slides anti-parallel microtubules (MTs), but it is unclear how these two activities contribute to the first steps in spindle formation. In this study, we report that in monopolar spindles, the duplicated spindle poles snap apart in a fast and irreversible step that produces a nascent bipolar spindle.

Single-cell analysis for drug development using convex lens-induced confinement imaging.

New technologies have powered rapid advances in cellular imaging, genomics and phenotypic analysis in life sciences. However, most of these methods operate at sample population levels and provide statistical averages of aggregated data that fail to capture single-cell heterogeneity, complicating drug discovery and development. Here we demonstrate a new single-cell approach based on convex lens-induced confinement (CLiC) microscopy.

Correction: Probing the organization and dynamics of two DNA chains trapped in a nanofluidic cavity.

Correction for 'Probing the organization and dynamics of two DNA chains trapped in a nanofluidic cavity' by Xavier Capaldi et al., Soft Matter, 2018, 14, 8455-8465.

Phase-field crystal for an antiferromagnet with elastic interactions.

We introduce a model which contains the essential elements to formulate and study antiferromagnetism, using the phase-field crystal framework. We focus on the question of how magneto-elastic coupling could lift the frustration in the two-dimensional hexagonal antiferromagnetic phase. Using simulations we observe a rich variety of different phases stable in this model.

Fully Quantized Electron Transfer Observed in a Single Redox Molecule at a Metal Interface.

Long-range electron transfer is a ubiquitous process that plays an important role in electrochemistry, biochemistry, organic electronics, and single molecule electronics. Fundamentally, quantum mechanical processes, at their core, manifest through both electron tunneling and the associated transition between quantized nuclear vibronic states (intramolecular vibrational relaxation) mediated by electron-nuclear coupling. Here, we report on measurements of long-range electron transfer at the interface between a single ferrocene molecule and a gold substrate separated by a hexadecanethiol quantum tunneling barrier.

Double-wave reentry in excitable media.

A monolayer of chick embryo cardiac cells grown in an annular geometry supports two simultaneous reentrant excitation waves that circulate as a doublet. We propose a mechanism that can lead to such behavior. The velocity restitution gives the instantaneous velocity of a wave as a function of the time since the passage of the previous wave at a given point in space.

Response of mechanically-created neurites to extension.

We use micromanipulation techniques and real-time particle tracking to develop an approach to study specific attributes of neuron mechanics. We use a mechanical probe composed of a hollow micropipette with its tip fixed to a functionalized bead to induce the formation of a neurite in a sample of rat hippocampal neurons. We then move the sample relative to the pipette tip, elongating the neurite while simultaneously measuring its tension by optically tracking the deflection of the beaded tip.

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements.

Recently, there have been a number of variations of electrostatic force microscopy (EFM) that allow for the measurement of time-varying forces arising from phenomena such as ion transport in battery materials or charge separation in photovoltaic systems. These forces reveal information about dynamic processes happening over nanometer length scales due to the nanometer-sized probe tips used in atomic force microscopy. Here, we review in detail several time-resolved EFM techniques based on non-contact atomic force microscopy, elaborating on their specific limitations and challenges.

Global analyses of Higgs portal singlet dark matter models using GAMBIT.

We present global analyses of effective Higgs portal dark matter models in the frequentist and Bayesian statistical frameworks. Complementing earlier studies of the scalar Higgs portal, we use GAMBIT to determine the preferred mass and coupling ranges for models with vector, Majorana and Dirac fermion dark matter. We also assess the relative plausibility of all four models using Bayesian model comparison.

Hydrogel droplet single-cell processing: DNA purification, handling, release, and on-chip linearization.

The preparation and handling of mammalian single-cell genomic DNA is limited by the complexity bottleneck inherent to performing multi-step, multi-reagent operations in a microfluidic environment. We have developed a method for benchtop preparation of high-molecular weight, intact, single-cell genomes and demonstrate the extraction of long nucleic acid molecules in a microfluidic system. Lymphoblasts are encapsulated inside of alginate microparticles using a droplet microfluidics, and cells are lysed in bulk.

In Silico Evolution of Biochemical Log-Response.

Numerous biological systems are known to harbor a form of logarithmic behavior, from Weber's law to bacterial chemotaxis. Such a log-response allows for sensitivity to small relative variations of biochemical inputs over a large range of concentration values. Here we use a genetic algorithm to evolve biochemical networks displaying a logarithmic response.

Modelling Time-Dependent Acquisition of Positional Information.

Theoretical and computational modelling are crucial to understand dynamics of embryonic development. In this tutorial chapter, we describe two models of gene networks performing time-dependent acquisition of positional information under control of a dynamic morphogen: a toy-model of a bistable gene under control of a morphogen, allowing for the numerical computation of a simple Waddington's epigenetic landscape, and a recently published model of gap genes in Tribolium under control of multiple enhancers. We present detailed commented implementations of the models using python and jupyter notebooks.

Elasticity of Nuclear Pasta.

The elastic properties of neutron star crusts are relevant for a variety of currently observable or near-future electromagnetic and gravitational wave phenomena. These phenomena may depend on the elastic properties of nuclear pasta found in the inner crust. We present large-scale classical molecular dynamics simulations where we deform nuclear pasta.

Relating Franck-Condon blockade to redox chemistry in the single-particle picture.

In this work, we explore Franck-Condon blockade in the "redox limit," where nuclear relaxation processes occur much faster than the rate of electron transfer. To this end, the quantized rate expressions for electron transfer are recast in terms of a quantized redox density of states (DOS) within a single phonon mode model. In the high temperature regime, this single-particle picture formulation of electron transfer is shown to agree well with the semi-classical rate and DOS expressions developed by Gerischer and Hopfield.

Probing the organization and dynamics of two DNA chains trapped in a nanofluidic cavity.

Here we present a pneumatically-actuated nanofluidic platform that has the capability of dynamically controlling the confinement environment of macromolecules in solution. Using a principle familiar from classic devices based on soft-lithography, the system uses pneumatic pressure to deflect a thin nitride lid into a nanoslit, confining molecules in an array of cavities embedded in the slit. We use this system to quantify the interactions of multiple confined DNA chains, a key problem in polymer physics with important implications for nanofluidic device performance and DNA partitioning/organization in bacteria and the eukaryotes.

Sub-microsecond-resolved multi-speckle X-ray photon correlation spectroscopy with a pixel array detector.

Small-angle X-ray photon correlation spectroscopy (XPCS) measurements spanning delay times from 826 ns to 52.8 s were performed using a photon-counting pixel array detector with a dynamic range of 0-3 (2 bits). Fine resolution and a wide dynamic range of time scales was achieved by combining two modes of operation of the detector: (i) continuous mode, where data acquisition and data readout are performed in parallel with a frame acquisition time of 19.