The (20)Ne interaction in extended matter

Although heavy ion transport theory is developed to a relatively advanced stage, the present limitation in biomedical and electronic applications is the uncertainty in nuclear fragmentation parameters. The present status on Ne-20 beams is discussed and useful formulae are presented for future use in analysis of beam transport experiments

Mechanistic modelling of a recombinase-based two-input temporal logic gate

Site-specific recombinases (SSRs) mediate efficient manipulation of DNA sequences in vitro and in vivo. In particular, serine integrases have been identified as highly effective tools for facilitating DNA inversion, enabling the design of genetic switches that are capable of turning the expression of a gene of interest on or off in the presence of a SSR protein. The functional scope of such circuitry can be extended to biological Boolean logic operations by incorporating two or more distinct integrase inputs. To date, mathematical modelling investigations have captured the dynamical properties of integrase logic gate systems in a purely qualitative manner, and thus such models are of limited utility as tools in the design of novel circuitry. Here, the authors develop a detailed mechanistic model of a two-input temporal logic gate circuit that can detect and encode sequences of input events. Their model demonstrates quantitative agreement with time-course data on the dynamics of the temporal logic gate, and is shown to subsequently predict dynamical responses relating to a series of induction separation intervals. The model can also be used to infer functional variations between distinct integrase inputs, and to examine the effect of reversing the roles of each integrase on logic gate output

Studies of HZE particle interactions and transport for space radiation protection purposes

The main emphasis is on developing general methods for accurately predicting high-energy heavy ion (HZE) particle interactions and transport for use by researchers in mission planning studies, in evaluating astronaut self-shielding factors, and in spacecraft shield design and optimization studies. The two research tasks are: (1) to develop computationally fast and accurate solutions to the Boltzmann (transport) equation; and (2) to develop accurate HZE interaction models, from fundamental physical considerations, for use as inputs into these transport codes. Accurate solutions to the HZE transport problem have been formulated through a combination of analytical and numerical techniques. In addition, theoretical models for the input interaction parameters are under development: stopping powers, nuclear absorption cross sections, and fragmentation parameters

Early Pollen Sensitization in Children Is Dependent upon Regional Aeroallergen Exposure

Introduction. Aeroallergen sensitization occurs at an earlier age than previously noted. The purpose of this paper was to identify which pollens cause early sensitization in young children presenting with rhinitis symptoms. Methods. This paper was a retrospective analysis of skin test results from 2- to 8-year-old patients presenting with a history consistent with allergic rhinitis. Patients were tested to aeroallergens common to the Great Basin along with a histamine and saline control. Pollen counts were obtained from a Reno, NV-certified counting station. Results. 123 children less than 8 years of age were identified. Over 50% of these children were sensitized to at least one aeroallergen. Chemopodaciae, timothy, alfalfa, black walnut, olive, mountain cedar and willow were predominating sensitizing aeroallergens of the Great Basin Region. Pollen counts were notable for a early spring peak for the tree season, grass season in May and weed season in August. Pollen levels continued to November at low levels. Discussion. Aeroallergens causing early sensitization differed from those which had predominately been reported in other regions of the United States. Pediatric allergists should consider performing a local review of sensitizing aeroallergens in their region to assist with identification and management of allergic rhinitis in their youngest patients. Please make style changes as appropriate

Single-cell zeroth-order protein degradation enhances the robustness of synthetic oscillator

In Escherichia coli, protein degradation in synthetic circuits is commonly achieved by the ssrA-tagged degradation system. In this work, we show that the degradation kinetics for the green fluorescent protein fused with the native ssrA tag in each cell exhibits the zeroth-order limit of the Michaelis–Menten kinetics, rather than the commonly assumed first-order. When measured in a population, the wide distribution of protein levels in the cells distorts the true kinetics and results in a first-order protein degradation kinetics as a population average. Using the synthetic gene-metabolic oscillator constructed previously, we demonstrated theoretically that the zeroth-order kinetics significantly enlarges the parameter space for oscillation and thus enhances the robustness of the design under parametric uncertainty

Paramaterizations of inclusive cross sections for pion production in proton-proton collisions. II. Comparison to new data

A set of new, precise data have recently been made available by the NA49 collaboration for charged pion production in proton-proton and proton-Carbon reactions at 158 GeV. The current paper compares this new data to five currently available arithmetic parameterizations. Although a precise fit is not expected, two of the parameterizations do not work very well but the other three are able to provide a moderately good, but not precise fit to the proton-proton data. The best two of these three parameterizations are scaled to the proton-Carbon data and again provide a moderately good, but not precise fit.Comment: 11 pages, 13 figures, Accepted for publication in Physical Review

Diagonal forms of incidence matrices associated with t-uniform hypergraphs

We consider integer matrices N_t(h) whose rows are indexed by the t-subsets of an n-set and whose columns are all images of a particular column h under the symmetric group S_n. Earlier work has determined a diagonal form for N_t(h) when h has at least t ‘isolated vertices’ and the results were applied to the binary case of a zerosum Ramsey-type problem of Alon and Caro involving t-uniform hypergraphs. This paper deals with the case that h does not have as many as t isolated vertices

Shift of the 21+^+_1 state of 10^{10}Be in the ternary cold fission of 252^{252}Cf

Recent experimental data indicate that in the ternary cold fission of $^{252}$Cf the energy of the first excited state of the accompanying light cluster $^{10}$Be is decreased by an amount ranging between $\approx$ 6 and 26 keV. A model is proposed to calculate the shift of the vibrational 2$^+_1$ state in $^{10}$Be when its heavy companions are the even-even nuclei $^{146}$Ba and $^{96}$Sr. The stiffness parameters of the $\beta$-vibrations are calculated within the self-consistent Hartree-Fock method with BCS pairing correlations taken into account, and its change is determined by the interaction of the light cluster with the heavy fragments. The results are pointing to a dependence of the shift magnitude and signature on the relative distance between the three clusters and their mutual orientation. Eventually it is the anharmonic perturbation of the spherical vibrator which is responsible for obtaining a negative energy shift of the 2$^+_1$ state.Comment: 4 pages, 3 figure

The relationships between internal and external threat and right-wing attitudes: A three-wave longitudinal study

The interplay between threat and right-wing attitudes has received much research attention, but its longitudinal relationship has hardly been investigated. In this study, we investigated the longitudinal relationships between internal and external threat and right-wing attitudes using a cross-lagged design at three different time points in a large nationally representative sample (N = 800). We found evidence for bidirectional relationships. Higher levels of external threat were related to higher levels of Right-Wing Authoritarianism and to both the egalitarianism and dominance dimensions of Social Dominance Orientation at a later point in time. Conversely, higher levels of RWA were also related to increased perception of external threat later in time. Internal threat did not yield significant direct or indirect longitudinal relationships with right-wing attitudes. Theoretical and practical implications of these longitudinal effects are discussed

A Quantum Langevin Formulation of Risk-Sensitive Optimal Control

In this paper we formulate a risk-sensitive optimal control problem for continuously monitored open quantum systems modelled by quantum Langevin equations. The optimal controller is expressed in terms of a modified conditional state, which we call a risk-sensitive state, that represents measurement knowledge tempered by the control purpose. One of the two components of the optimal controller is dynamic, a filter that computes the risk-sensitive state. The second component is an optimal control feedback function that is found by solving the dynamic programming equation. The optimal controller can be implemented using classical electronics. The ideas are illustrated using an example of feedback control of a two-level atom