Density functional theory for molecular multiphoton ionization in the perturbative regime

A general implementation of the lowest nonvanishing order perturbation theory for the calculation of molecular multiphoton ionization cross sections is proposed in the framework of density functional theory. Bound and scattering wave functions are expanded in a multicentric basis set and advantage is taken of the full molecular point group symmetry, thus enabling the application of the formalism to medium-size molecules. Multiphoton ionization cross sections and angular asymmetry parameters have been calculated for the two- and four-photon ionization of the H2+ molecule, for linear and circular light polarizations. Both fixed and random orientations of the target molecule have been considered. To demonstrate the efficiency of the proposed methodology, the two-photon cross section and angular asymmetry parameters for the HOMO and HOMO-1 orbital ionization of benzene are also presented

A simple trapped-ion architecture for high-fidelity Toffoli gates

We discuss a simple architecture for a quantum Toffoli gate implemented using three trapped ions. The gate, which in principle can be implemented with a single laser-induced operation, is effective under rather general conditions and is strikingly robust (within any experimentally realistic range of values) against dephasing, heating and random fluctuations of the Hamiltonian parameters. We provide a full characterization of the unitary and noise-affected gate using three-qubit quantum process tomography

Why 'scaffolding' is the wrong metaphor : the cognitive usefulness of mathematical representations.

The metaphor of scaffolding has become current in discussions of the cognitive help we get from artefacts, environmental affordances and each other. Consideration of mathematical tools and representations indicates that in these cases at least (and plausibly for others), scaffolding is the wrong picture, because scaffolding in good order is immobile, temporary and crude. Mathematical representations can be manipulated, are not temporary structures to aid development, and are refined. Reflection on examples from elementary algebra indicates that Menary is on the right track with his ‘enculturation’ view of mathematical cognition. Moreover, these examples allow us to elaborate his remarks on the uniqueness of mathematical representations and their role in the emergence of new thoughts.Peer reviewe

Energy Transport in an Ising Disordered Model

We introduce a new microcanonical dynamics for a large class of Ising systems isolated or maintained out of equilibrium by contact with thermostats at different temperatures. Such a dynamics is very general and can be used in a wide range of situations, including disordered and topologically inhomogenous systems. Focusing on the two-dimensional ferromagnetic case, we show that the equilibrium temperature is naturally defined, and it can be consistently extended as a local temperature when far from equilibrium. This holds for homogeneous as well as for disordered systems. In particular, we will consider a system characterized by ferromagnetic random couplings $J_{ij} \in [ 1 - \epsilon, 1 + \epsilon ]$. We show that the dynamics relaxes to steady states, and that heat transport can be described on the average by means of a Fourier equation. The presence of disorder reduces the conductivity, the effect being especially appreciable for low temperatures. We finally discuss a possible singular behaviour arising for small disorder, i.e. in the limit $\epsilon \to 0$.Comment: 14 pages, 8 figure

Simple Realization Of The Fredkin Gate Using A Series Of Two-body Operators

The Fredkin three-bit gate is universal for computational logic, and is reversible. Classically, it is impossible to do universal computation using reversible two-bit gates only. Here we construct the Fredkin gate using a combination of six two-body reversible (quantum) operators.Comment: Revtex 3.0, 7 pages, 3 figures appended at the end, please refer to the comment lines at the beginning of the manuscript for reasons of replacemen

Density Functional Theory for the Photoionization Dynamics of Uracil

Photoionization dynamics of the RNA base Uracil is studied in the framework of Density Functional Theory (DFT). The photoionization calculations take advantage of a newly developed parallel version of a multicentric approach to the calculation of the electronic continuum spectrum which uses a set of B-spline radial basis functions and a Kohn-Sham density functional hamiltonian. Both valence and core ionizations are considered. Scattering resonances in selected single-particle ionization channels are classified by the symmetry of the resonant state and the peak energy position in the photoelectron kinetic energy scale; the present results highlight once more the site specificity of core ionization processes. We further suggest that the resonant structures previously characterized in low-energy electron collision experiments are partly shifted below threshold by the photoionization processes. A critical evaluation of the theoretical results providing a guide for future experimental work on similar biosystems

Field ultrasound evaluation of some gestational parameters in jennies

The aim of this study was to collect and analyze ultrasound measurements of fetal-maternal structures during normal and pathological pregnancies in jennies, a livestock species of growing interest. For two breeding seasons, 38 jennies of different breeds and crossbreeds aged between 3 and 18 years were monitored weekly by transrectal examination using a portable Esaote ultrasound (MyLab\u2122 30 GOLD VET) with a 5\u20137.5 MHz probe. The jennies were divided into two groups, < 250 kg and >250 kg body weight, and the dates of conception and parturition/abortion were recorded to calculate pregnancy length. Descriptive statistics were performed for the following variables: pregnancy length and maternal-fetal parameters (measurements of the orbit, gastric bubble, thorax, abdomen, gonads, heart rate, umbilical artery velocimetry, and combined utero-placental thickness). A total of 68 pregnancies were studied, 36 of which ended during the study period. The average pregnancy length was 370.82 \ub1 16.6 days for full-term pregnancies (N = 28, 77.8%) and 316.13 \ub1 36.6 days for abortions (N = 8, 22.2%). The season of conception and fetal gender did not affect the pregnancy length. Pregnancy examination can reasonably be performed by two weeks after last service if ovulation date is not known. The orbital diameter was the most reliable parameter for monitoring the physiological development of the embryo and fetus, and it was strongly related to the gestational age. No differences in fetal development were observed in relation to the mother's body weight. The combined utero-placental thickness was not associated with the gestational age and thickening and edema, frequently observed, were not associated with fetal pathologies

Model predictions of wave overwash extent into the marginal ice zone

A model of the extent of wave driven overwash into fields of sea ice floes is proposed. The extent model builds on previous work modelling wave overwash of a single floe by regular waves by including irregular incoming waves and random floe fields. The model is validated against a laboratory experiment. It is then used to study the extent of wave overwash into marginal ice zones consisting of pancake and fragmented floe fields. The effects of wave conditions and floe geometry on predicted extents are investigated. Finally, the model is used to predict the wave overwash extent for the conditions observed during a winter (July) 2017 Antarctic voyage in which the sea surface was monitored by a stereo-camera system

TRAIL treatment prevents renal morphological changes and TGF-\u3b2-induced mesenchymal transition associated with diabetic nephropathy

BACKGROUND: TNF-related apoptosis-inducing ligand (TRAIL) has attracted attention not only as an anti-cancer agent, but also as a potential treatment for diabetes. Animal studies have shown that TRAIL delivery ameliorated glucose control in type 1 and type 2 diabetes. It is currently unknown whether TRAIL positive effects are maintained in more severe forms of type 2 diabetes, and whether they include renoprotection. Our study aimed at evaluating TRAIL effects in a severe form of type 2 diabetes with nephropathy. MATERIALS AND METHODS: A total of 20 db/db mice were treated with saline or TRAIL twice per week for 12 weeks. In parallel, renal tubular epithelial cells were cultured with TGF-\u3b21 in the presence and absence of TRAIL, with and without silencing TRAIL-specific receptor (DR5) and leptin receptor. RESULTS: TRAIL did not improve glucose control, but it significantly reduced circulating interleukin (IL)-6 and resistin. In the kidney, TRAIL treatment significantly ameliorated glomerular and tubular morphology with an improvement in kidney function, but no effect on proteinuria. Our in vitro studies on TGF-\u3b21-treated cells, showed that by binding to DR5, TRAIL rescued normal tubular cell morphology, increasing E-cadherin and reducing \u3b1-smooth muscle actin (SMA) expression, with no effects on cell viability. Interestingly, both in vivo and in vitro, TRAIL reduced the accumulation of the autophagy substrate p62. CONCLUSIONS: Our data confirm TRAIL protective effects against organ damage and shed light on to promising anti-fibrotic actions, which are independent of glucose control. TRAIL anti-fibrotic actions might be due to the rescue of autophagy in diabetes

On the origin of ambiguity in efficient communication

This article studies the emergence of ambiguity in communication through the concept of logical irreversibility and within the framework of Shannon's information theory. This leads us to a precise and general expression of the intuition behind Zipf's vocabulary balance in terms of a symmetry equation between the complexities of the coding and the decoding processes that imposes an unavoidable amount of logical uncertainty in natural communication. Accordingly, the emergence of irreversible computations is required if the complexities of the coding and the decoding processes are balanced in a symmetric scenario, which means that the emergence of ambiguous codes is a necessary condition for natural communication to succeed.Comment: 28 pages, 2 figure