Behavioral and computational aspects of language and its acquisition

One of the greatest challenges facing the cognitive sciences is to explain what it means to know a language, and how the knowledge of language is acquired. The dominant approach to this challenge within linguistics has been to seek an efficient characterization of the wealth of documented structural properties of language in terms of a compact generative grammar—ideally, the minimal necessary set of innate, universal, exception-less, highly abstract rules that jointly generate all and only the observed phenomena and are common to all human languages. We review developmental, behavioral, and computational evidence that seems to favor an alternative view of language, according to which linguistic structures are generated by a large, open set of constructions of varying degrees of abstraction and complexity, which embody both form and meaning and are acquired through socially situated experience in a given language community, by probabilistic learning algorithms that resemble those at work in other cognitive modalities.     

Studies of the parameters of a transverse volume discharge in a Ne-SF<Subscript>6</Subscript>-C<Subscript>6</Subscript>H<Subscript>14</Subscript> mixture

Results are presented from studies of the electric and emission parameters of transverse volume discharges in neon-sulfur-hexafluoride-propane mixtures at a total pressure of 3–12 kPa. The spatial characteristics of a transverse volume discharge, the plasma radiation spectra in the 130- to 550-nm wavelength range, the waveforms of the discharge voltage and current, and the yield of carbonic products of propane decomposition are investigated at different pressures and different composition of the Ne-SF₆-C₆H₁₄ mixture.     

A holographic model of deconfinement and chiral symmetry restoration

We analyze the finite temperature behavior of the Sakai-Sugimoto model, which is a holographic dual of a theory which spontaneously breaks a U(N_f)_L × U(N_f)_R chiral flavor symmetry at zero temperature. The theory involved is a 4 + 1 dimensional supersymmetric SU(N_c) gauge theory compactified on a circle of radius R with anti-periodic boundary conditions for fermions, coupled to N_f left-handed quarks and N_f right-handed quarks which are localized at different points on the compact circle (separated by a distance L). In the supergravity limit which we analyze (corresponding in particular to the large N_c limit of the gauge theory), the theory undergoes a deconfinement phase transition at a temperature T_d = 1/2πR. For quark separations obeying L > L_c ? 0.97 ∗ R the chiral symmetry is restored at this temperature, but for L < L_c ? 0.97 ∗ R there is an intermediate phase which is deconfined with broken chiral symmetry, and the chiral symmetry is restored at T_χSB ? 0.154/L. All of these phase transitions are of first order.     

Synthesis of new thieno and pyrazolo[2,1]benzothiazepine derivatives with potential antidepressant properties

In this paper we describe a series of new thieno and pyrazolo[2,1]benzothiazepine derivatives 7a‐o which were synthesized by two different methods both starting from the previously described tricyclic alcohols 1–3 . Several components of this series were effective p. o. (per os, orally) in different pharmacological tests currently employed in the evaluation of antidepressant activity.     

Coupled Amplitude-Streaming Flow Equations for Nearly Inviscid Faraday Waves in Small Aspect Ratio Containers

Summary. We derive a set of asymptotically exact coupled amplitude-streaming flow ({CASF}) equations governing the evolution of weakly nonlinear nearly inviscid multimode Faraday waves and the associated streaming flow in finite geometries. The streaming flow is found to play a particularly important role near mode interactions. Such interactions come about either through a suitable choice of parameters or through breaking of degeneracy among modes related by symmetry. An example of the first case is provided by the interaction of two nonaxisymmetric modes in a circular container with different azimuthal wavenumbers. The second case arises when the shape of the container is changed from square to slightly rectangular, or from circular to slightly noncircular but with a plane of symmetry. The generation of streaming flow in each of these cases is discussed in detail and the properties of the resulting CASF equations are described. A preliminary analysis suggests that these equations can resolve discrepancies between existing theory and experimental results in the first two of the above cases.     

Amended Formula for the Decay of Radioactive Material for Cosmic Times

An amended formula for the decay of radioactivematerial is presented. It is a modification of thestandard exponential formula. The new formula appliesfor long cosmic times comparable to the Hubble time. It reduces to the standard formula for shorttimes. It is shown that the material decays faster thanexpected. The application of the new formula to directmeasurements of the age of the universe and its implications are briefly discussed.     

The catwalk task: Reflections and synthesis: Part 2

In this article we recount our experiences with a series of encounters with the catwalk task and reflect on the professional growth that these opportunities afforded. First, we individually reflect on our own mathematical work on the catwalk task. Second, we reflect on our experiences working with a group of community college students on the catwalk task and our interpretations of their mathematical thinking. In so doing we also detail a number of innovative and novel student-generated representations of the catwalk photos. Finally, we each individually reflect on the entire experience with the catwalk problem, as mathematics learners, as teachers, and as professionals.     

Oscillator strengths and photoionisation cross sections for Rydberg transitions in acetaldehyde

Oscillator strengths for electronic transitions involving Rydberg states of acetaldehyde, as well as cross sections for all the dipole allowed photoionisation channels, all ending in the ground state of the molecular cation, are reported. The molecular quantum defect orbital method, which has proved to be reliable in previous applications to molecular Rydberg states, has been used. Despite its relevance for atmospheric chemistry and astrophysics, only a few data seem to be available in the literature. The continuity of the calculated differential oscillator strength across the ionisation threshold has been adopted as a quality criterion. To our knowledge, predictions of oscillator strengths for transitions to high-lying Rydberg states, as well as of photoionisation profiles on acetaldehyde are made here for the first time and we are not aware of any reported experimental data. We, thus, hope the present results may be useful in the interpretation of the spectrum of acetaldehyde and might be of help in future experimental measurements.