Origins of limited non-basal plasticity in {\mu}-phase at room temperature

We unveil a new non-basal slip mechanism in the {\mu}-phase at room temperature using nanomechanical testing, transmission electron microscopy and atomistic simulations. The (1-105) planar faults with a displacement vector of 0.07[-5502] can be formed by dislocation glide. They do not disrupt the Frank-Kasper packing and therefore enable the accommodation of plastic strain at low temperatures without requiring atomic diffusion. The intersections between the (1-105) planar faults and basal slip result in stress concentration and crack nucleation during loading

Forward displacements of fading objects in motion: the role of transient signals in perceiving position

Visual motion causes mislocalisation phenomena in a variety of experimental paradigms. For many displays objects are perceived as displaced 'forward' in the direction of motion. However, in some cases involving the abrupt stopping or reversal of motion the forward displacements are not observed. We propose that the transient neural signals at the offset of a moving object play a crucial role in accurate localisation. In the present study, we eliminated the transient signals at motion offset by gradually reducing the luminance of the moving object. Our results show that the 'disappearance threshold' for a moving object is lower than the detection threshold for the same object without a motion history. In units of time this manipulation led to a forward displacement of the disappearance point by 175ms. We propose an explanation of our results in terms of two processes: Forward displacements are caused by internal models predicting positions of moving objects. The usually observed correct localisation of stopping positions, however, is based on transient inputs that retroactively attenuate errors that internal models might otherwise cause. Both processes are geared to reducing localisation errors for moving objects

Dislocation-mediated plasticity in the Al2_{2}Cu {\theta}-phase

The deformation behaviour of the intermetallic Al$_{2}$Cu-phase was investigated using atomistic simulations and micropillar compression, where slip on the unexpected {211} and {022} slip planes was revealed. Additionally, all possible slip systems for the intermetallic phases were further evaluated and a preference for the activation of slip systems based on their effective interplanar distances as well as the effective Burgers vector is proposed. The effective interplanar distance corresponds to the manually determined interplanar distance, whereas the effective Burgers vector takes a potential dislocation dissociation into account. This new order is: {211}1/2, {022}1/2 and {022}, {110}, {310}, {022}, {110}1/2, {112} and {112}1/2 from high to low ratio of deff/beff. Also, data on the critical resolved shear stresses of several of these slip systems were measured.Comment: 27 pages, 17 figure

Facing the Spectator

We investigated the familiar phenomenon of the uncanny feeling that represented people in frontal pose invariably appear to ‘‘face you’’ from wherever you stand. We deploy two different methods. The stimuli include the conventional one—a flat portrait rocking back and forth about a vertical axis—augmented with two novel variations. In one alternative, the portrait frame rotates whereas the actual portrait stays motionless and fronto-parallel; in the other, we replace the (flat!) portrait with a volumetric object. These variations yield exactly the same optical stimulation in frontal view, but become grossly different in very oblique views. We also let participants sample their momentary awareness through ‘‘gauge object’’ settings in static displays. From our results, we conclude that the psychogenesis of visual awareness maintains a number—at least two, but most likely more—of distinct spatial frameworks simultaneously involving ‘‘cue–scission.’’ Cues may be effective in one of these spatial frameworks but ineffective or functionally different in other ones

Attenuated asthma phenotype in mice with a fetal-like antigen receptor repertoire

We hypothesized that the scarcity of N-nucleotides might contribute to the inability of the neonate to mount a robust allergic immune response. To test this, we used terminal deoxyribunucleotidyl Transferase defcient (TdT−/−) mice, which express “fetal-like” T cell receptor and immunoglobulin repertoires with largely germline-encoded CDR3 regions. Intraperitoneal sensitization was followed by aerosol provocation with either PBS or the allergen OVA in both TdT−/− mice and wild-type mice to develop allergic respiratory infammation. The efects of this procedure were investigated by lung function test, immunological analysis of serum and brochoalveolar lavage. The local TH2 cytokine milieu was signifcantly attenuated in TdT−/− mice. Within this group, the induction of total IgE levels was also signifcantly reduced after sensitization. TdT−/− mice showed a tendency toward reduced eosinophilic infow into the bronchial tubes, which was associated with the elimination of respiratory hyperreactivity. In conclusion, in a murine model of allergic airway infammation, the expression of fetal-like antigen receptors was associated with potent indications of a reduced ability to mount an asthma phenotype. This underlines the importance of somatically-generated antigen-receptor repertoire diversity in type one allergic immune responses and suggests that the fetus may be protected from allergic responses, at least in part, by controlling N addition

Measurement and Interpretation of Fermion-Pair Production at LEP energies above the Z Resonance

This paper presents DELPHI measurements and interpretations of cross-sections, forward-backward asymmetries, and angular distributions, for the e+e- -> ffbar process for centre-of-mass energies above the Z resonance, from sqrt(s) ~ 130 - 207 GeV at the LEP collider. The measurements are consistent with the predictions of the Standard Model and are used to study a variety of models including the S-Matrix ansatz for e+e- -> ffbar scattering and several models which include physics beyond the Standard Model: the exchange of Z' bosons, contact interactions between fermions, the exchange of gravitons in large extra dimensions and the exchange of sneutrino in R-parity violating supersymmetry.Comment: 79 pages, 16 figures, Accepted by Eur. Phys. J.

Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0

Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.

Determination of the b quark mass at the M_Z scale with the DELPHI detector at LEP

An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light= \ell \equiv u,d,s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: M_b and the b running mass: m_b(M_Z). Data are found to be better described when using the running mass. The measurement yields: m_b(M_Z) = 2.85 +/- 0.18 (stat) +/- 0.13 (exp) +/- 0.19 (had) +/- 0.12 (theo) GeV/c^2 for the CAMBRIDGE algorithm. This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of Quantum Chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 permil.Comment: 24 pages, 10 figures, Accepted by Eur. Phys. J.

A Determination of the Centre-of-Mass Energy at LEP2 using Radiative 2-fermion Events

Using e+e- -> mu+mu-(gamma) and e+e- -> qqbar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, sqrt{s}, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.Comment: 20 pages, 6 figures, Accepted by Eur. Phys. J.