Introducing the Emerging Discipline of Statistics Education

Increasing attention has been given over the last decade by the statistics, mathematics and science education communities to the development of statistical literacy and numeracy skills of all citizens and the enhancement of statistics education at all levels. This paper introduces the emerging discipline of statistics education and considers its role in the development of these important skills. The paper begins with information on the growing importance of statistics in today's society, schools and colleges, summarizes unique challenges students face as they learn statistics, and makes a case for the importance of collaboration between mathematicians and statisticians in preparing teachers to teach students how to understand and reason about data. We discuss the differences and interrelations between statistics and mathematics, recognizing that mathematics is the discipline that has traditionally included instruction in statistics. We conclude with an argument that statistics should be viewed as a bridge between mathematics and science and should be taught in both disciplines.     

Interacting effects of syllable and phrase position on consonant articulation

The complexities of how prosodic structure, both at the phrasal and syllable levels, shapes speech production have begun to be illuminated through studies of articulatory behavior. The present study contributes to an understanding of prosodic signatures on articulation by examining the joint effects of phrasal and syllable position on the production of consonants. Articulatory kinematic data were collected for five subjects using electromagnetic articulography (EMA) to record target consonants (labial, labiodental, and tongue tip), located in (1) either syllable final or initial position and (2) either at a phrase edge or phrase medially. Spatial and temporal characteristics of the consonantal constriction formation and release were determined based on kinematic landmarks in the articulator velocity profiles. The results indicate that syllable and phrasal position consistently affect the movement duration; however, effects on displacement were more variable. For most subjects, the boundary-adjacent portions of the movement (constriction release for a preboundary coda and constriction formation for a postboundary onset) are not differentially affected in terms of phrasal lengthening-both lengthen comparably.     

Synthesis of new artemisinin-derived dimers by self-cross-metathesis reaction

[reaction: see text] New artemisinin-derived dimers, fluorinated or not, have been prepared by a self-cross metathesis reaction in the presence of first- or second-generation ruthenium catalysts without degradation of the endoperoxide bridge and with a good E/Z selectivity (up to 100:0).     

On ergodic averages for affine lattice actions on tori

We prove that for a ?^ν-action on a torus as a group of affine transformations all the ergodic averages exist if and only if all the eigenvalues of the automorphism parts of all the affine transformations are roots of unity.     

Recent Advances in Molecularly Imprinted Polymers for Antibiotic Analysis

The abuse and residues of antibiotics have a great impact on the environment and organisms, and their determination has become very important. Due to their low contents, varieties and complex matrices, effective recognition, separation and enrichment are usually required prior to determination. Molecularly imprinted polymers (MIPs), a kind of highly selective polymer prepared via molecular imprinting technology (MIT), are used widely in the analytical detection of antibiotics, as adsorbents of solid-phase extraction (SPE) and as recognition elements of sensors. Herein, recent advances in MIPs for antibiotic residue analysis are reviewed. Firstly, several new preparation techniques of MIPs for detecting antibiotics are briefly introduced, including surface imprinting, nanoimprinting, living/controlled radical polymerization, and multi-template imprinting, multi-functional monomer imprinting and dummy template imprinting. Secondly, several SPE modes based on MIPs are summarized, namely packed SPE, magnetic SPE, dispersive SPE, matrix solid-phase dispersive extraction, solid-phase microextraction, stir-bar sorptive extraction and pipette-tip SPE. Thirdly, the basic principles of MIP-based sensors and three sensing modes, including electrochemical sensing, optical sensing and mass sensing, are also outlined. Fourthly, the research progress on molecularly imprinted SPEs (MISPEs) and MIP-based electrochemical/optical/mass sensors for the detection of various antibiotic residues in environmental and food samples since 2018 are comprehensively reviewed, including sulfonamides, quinolones, β-lactams and so on. Finally, the preparation and application prospects of MIPs for detecting antibiotics are outlined.     

An unconditionally stable time-domain discretization on cartesian meshes for the simulation of nonuniform magnetized cold plasma

In this paper an unconditionally stable, spatially and temporally implicit time-domain discretization for nonuniform magnetized cold plasma is developed. The discrete dispersion relation is free of spurious solutions and approximates the continuous dispersion relation for well-resolved wavelengths and frequencies (kΔ ? π, ωΔ_t ? π). For a specific choice of parameters, the discrete dispersion relation approximates the continuous dispersion relation for all wavelengths and frequencies up to the Nyquist limit. A few examples, amongst them one involving mode conversion, illustrate the new method.