The symmetry problem: current theories and prospects

The structural approach to alternatives (Katzir in Linguist Philos 30(6):669–690, 2007; Fox and Katzir in Nat Lang Semant 19(1):87–107, 2011; Katzir in Semantics, pragmatics and the case of scalar implicatures, Palgrave Macmillan, London, pp 40–71, 2014) is the most developed attempt in the literature at solving the symmetry problem of scalar implicatures. Problematic data with indirect and particularised scalar implicatures have however been raised (Romoli in Snippets 27:14–15, 2013; Trinh and Haida in Nat Lang Semant 25(4):249–270, 2015). To address these problems, Trinh and Haida (2015) proposed to augment the theory with the Atomicity Constraint. Here we show that this constraint falls short of explaining minimal variants of the original problems, and moreover that it runs into trouble with the inferences of sentences involving gradable adjectives like full and empty. We furthermore discuss how the structural approach suffers at times from the problem of ‘too many lexical alternatives’ pointed out by Swanson (Linguist Philos 33(1):31–36, 2010), and at other times from the opposite problem of ‘too few lexical alternatives’. These three problems epitomise the challenge of constructing just enough alternatives under the structural approach to solve the symmetry problem in full generality. Finally, we also sketch another recent attempt at solving the symmetry problem, Bergen et al. (Semant Pragmat 9(20), 2016), which is based on relative informativity and complexity. We argue that Bergen et al. do not provide a general solution to the symmetry problem either, by pointing to some of the open problematic cases that remain for this approach as well. We conclude that while important progress has been made in the theory of alternatives for scalar implicatures in the last few years, a full solution to the symmetry problem has not yet been attained

Probing the 6He halo structure with elastic and inelastic proton scattering

Proton elastic scattering and inelastic scattering to the first excited state of 6He have been measured over a wide angular range using a 40.9A MeV 6He beam. The data have been analyzed with a fully microscopic model of proton-nucleus scattering using 6He wave functions generated from large space shell model calculations. The inelastic scattering data show a remarkable sensitivity to the halo structure of 6He.Comment: 9 pages, 3 figures. RevTeX. Replaced figure 3 with updated figur

alpha-particle production in the scattering of 6He by 208Pb at energies around the Coulomb barrier

New experimental data from the scattering of 6He+208Pb at energies around and below the Coulomb barrier are presented. The yield of breakup products coming from projectile fragmentation is dominated by a strong group of $\alpha$ particles. The energy and angular distributions of this group have been analyzed and compared with theoretical calculations. This analysis indicates that the $\alpha$ particles emitted at backward angles in this reaction are mainly due to two-neutron transfer to weakly bound states of the final nucleus.Comment: 20 pages, 5 figures. Nuclear Physics A792 (2007) 2-1

The cleanability of laser etched surfaces with repeated fouling using Staphylococcus aureus and milk

Biofouling is a serious problem in the food industry, and one way to control biofouling is using topographically patterned surfaces. This in vitro study used a laser surface texturing process to produce six differently patterned topographies which were analysed for their topography and wettability with repeated fouling and cleaning. The surfaces were spray-inoculated with Staphylococcus aureus suspended in either sterile distilled water or whole milk, then spray-cleaned using a chlorinated, alkaline cleaner. The surfaces were cleaned up to 20 times and analysed for changes in their surface properties and biofouling. Analysis of Variance was used to assess the effect of the main factors and two-way interactions. Principal component analysis was used to discern underlying relationships. There were no significant differences (T-Tests) in the overall level of biofouling between the different rippled sub-textures. The spiked surfaces showed no overall increase in biofouling and the number of cleans but were predominantly influenced by the texture sub-type. The less regular spiked surfaces within the medium range showed the lowest levels of biofouling, even with repeated cleaning. This study demonstrated that the use of such surfaces in in vitro studies may reduce biofouling, but particular attention needs to be given to the surface design

Waves and Magnetism in the Solar Atmosphere (WAMIS)

Comprehensive measurements of magnetic fields in the solar corona have a long history as an important scientific goal. Besides being crucial to understanding coronal structures and the Sun's generation of space weather, direct measurements of their strength and direction are also crucial steps in understanding observed wave motions. In this regard, the remote sensing instrumentation used to make coronal magnetic field measurements is well suited to measuring the Doppler signature of waves in the solar structures. In this paper, we describe the design and scientific values of the Waves and Magnetism in the Solar Atmosphere (WAMIS) investigation. WAMIS, taking advantage of greatly improved infrared filters and detectors, forward models, advanced diagnostic tools and inversion codes, is a long-duration high-altitude balloon payload designed to obtain a breakthrough in the measurement of coronal magnetic fields and in advancing the understanding of the interaction of these fields with space plasmas. It consists of a 20 cm aperture coronagraph with a visible-IR spectro-polarimeter focal plane assembly. The balloon altitude would provide minimum sky background and atmospheric scattering at the wavelengths in which these observations are made. It would also enable continuous measurements of the strength and direction of coronal magnetic fields without interruptions from the day–night cycle and weather. These measurements will be made over a large field-of-view allowing one to distinguish the magnetic signatures of different coronal structures, and at the spatial and temporal resolutions required to address outstanding problems in coronal physics. Additionally, WAMIS could obtain near simultaneous observations of the electron scattered K-corona for context and to obtain the electron density. These comprehensive observations are not provided by any current single ground-based or space observatory. The fundamental advancements achieved by the near-space observations of WAMIS on coronal field would point the way for future ground based and orbital instrumentation

Breakup and neutron-transfer effects on 6He+206Pb elastic scattering below the Coulomb barrier

The elastic scattering and inclusive α-particle yield for the 6He + 206Pb system at an incident energy of 18 MeV, just below the nominal Coulomb barrier, have been measured. The α-particle yield at forward angles is also reported. The data are analyzed by means of continuum-discretized coupled-channels, distorted wave Born approximation, and coupled reaction channels calculations. Couplings to the one-neutron- and two-neutron-transfer reactions are found to be able to account for most of the absorption in the entrance channel.This work was supported in part by Grant No. FPA2010-22131-C02-01 from the Spanish Ministry of Science.Departamento de Física AplicadaDepartamento de Ingeniería Eléctrica y Térmic

Sub-barrier fusion of 6He with 206Pb

Cross-sections for the production of 210Po nuclei in 6He + 206Pb collisions over the incident energy range 14–18MeV were measured by means of the activation technique and a radiochemical analysis. The elastic scattering at 18.0MeV was also measured providing a precise value for the 210Po production cross-section at this energy. The results are at variance with the earlier experimental data and rather in accord with the predictions of a density-dependent barrier penetration model for the fusion process. A proper treatment of beam energy distribution for the evaluation of the activation data is discussed

Practical and clinical utility of non-invasive vagus nerve stimulation (nVNS) for the acute treatment of migraine. A post hoc analysis of the randomized, sham-controlled, double-blind PRESTO trial

Background: The PRESTO study of non-invasive vagus nerve stimulation (nVNS; gammaCore®) featured key primary and secondary end points recommended by the International Headache Society to provide Class I evidence that for patients with an episodic migraine, nVNS significantly increases the probability of having mild pain or being pain-free 2 h post stimulation. Here, we examined additional data from PRESTO to provide further insights into the practical utility of nVNS by evaluating its ability to consistently deliver clinically meaningful improvements in pain intensity while reducing the need for rescue medication. Methods: Patients recorded pain intensity for treated migraine attacks on a 4-point scale. Data were examined to compare nVNS and sham with regard to the percentage of patients who benefited by at least 1 point in pain intensity. We also assessed the percentage of attacks that required rescue medication and pain-free rates stratified by pain intensity at treatment initiation. Results: A significantly higher percentage of patients who used acute nVNS treatment (n = 120) vs sham (n = 123) reported a ≥ 1-point decrease in pain intensity at 30 min (nVNS, 32.2%; sham, 18.5%; P = 0.020), 60 min (nVNS, 38.8%; sham, 24.0%; P = 0.017), and 120 min (nVNS, 46.8%; sham, 26.2%; P = 0.002) after the first attack. Similar significant results were seen when assessing the benefit in all attacks. The proportion of patients who did not require rescue medication was significantly higher with nVNS than with sham for the first attack (nVNS, 59.3%; sham, 41.9%; P = 0.013) and all attacks (nVNS, 52.3%; sham, 37.3%; P = 0.008). When initial pain intensity was mild, the percentage of patients with no pain after treatment was significantly higher with nVNS than with sham at 60 min (all attacks: nVNS, 37.0%; sham, 21.2%; P = 0.025) and 120 min (first attack: nVNS, 50.0%; sham, 25.0%; P = 0.018; all attacks: nVNS, 46.7%; sham, 30.1%; P = 0.037). Conclusions: This post hoc analysis demonstrated that acute nVNS treatment quickly and consistently reduced pain intensity while decreasing rescue medication use. These clinical benefits provide guidance in the optimal use of nVNS in everyday practice, which can potentially reduce use of acute pharmacologic medications and their associated adverse events. Trial registration: ClinicalTrials.gov identifier: NCT02686034

Study of the threshold anomaly effect in the reaction 7 Li+ 208 Pb at energies around the Coulomb barrier

The elastic scattering in the reaction7Li+208Pb was investigated in the bombarding energy range from 25 to39 MeV. The real and imaginary parts of the optical potential were analyzed by using a phenomenological potential. A dispersion relation analysis is presented in order to investigate the threshold anomaly effect. It is concluded that7Li has an intermediate behavior between the tightly bound nuclei suchas16O and the loosely bound nuclei such as6Li where the lack of the threshold anomaly is unambiguously observed.Reaction cross sections are also extracted from the elastic scattering data and its comparison with the ones of other systems has been performed to draw hints on the effect of the breakup channel