Early Modern Classicism and Late Imperial China

Most historians treat late imperial China, 1400-1900, as a time of fading and decay. Indeed, viewed backwards from the Opium War (1839-1842) and Taiping Rebellion (1850-1864), events before 1800 appear to have left China unprepared for modernity. But the 17th and 18th centuries can be considered not only as a 'late imperial' prelude to the end of traditional China, but as an 'early modern' harbinger of things to come

Single-particle shell strengths near the doubly magic nucleus 56Ni and the 56Ni(p,γ)57Cu reaction rate in explosive astrophysical burning

Angle-integrated cross-section measurements of the 56Ni(d,n) and (d,p) stripping reactions have been performed to determine the single-particle strengths of low-lying excited states in the mirror nuclei pair 57Cu−57Ni situated adjacent to the doubly magic nucleus 56Ni. The reactions were studied in inverse kinematics utilizing a beam of radioactive 56Ni ions in conjunction with the GRETINA γ-array. Spectroscopic factors are compared with new shell-model calculations using a full pf model space with the GPFX1A Hamiltonian for the isospin-conserving strong interaction plus Coulomb and charge-dependent Hamiltonians. These results were used to set new constraints on the 56Ni(p,γ)57Cu reaction rate for explosive burning conditions in x-ray bursts, where 56Ni represents a key waiting point in the astrophysical rp-process.peerReviewe

Two-neutron knockout as a probe of the composition of states in Mg 22, Al 23, and Si 24

Simpson and Tostevin proposed that the width and shape of exclusive parallel momentum distributions of the A−2 residue in direct two-nucleon knockout reactions carry a measurable sensitivity to the nucleon single-particle configurations and their couplings within the wave functions of exotic nuclei. We report here on the first benchmarks and use of this new spectroscopic tool. Exclusive parallel momentum distributions for states in the neutron-deficient nuclei 22Mg, 23Al, and 24Si populated in such direct two-neutron removal reactions were extracted and compared to predictions combining eikonal reaction theory and shell-model calculations. For the well-known 22Mg and 23Al nuclei, measurements and calculations were found to agree, supporting the dependence of the parallel momentum distribution width on the angular momentum composition of the shell-model two-neutron amplitudes. In 24Si, a level at 3439(9) keV, of relevance for the important 23Al (p,γ) 24Si astrophysical reaction rate, was confirmed to be the 2+2 state, whereas the 4 + 1 state, expected to be strongly populated in two-neutron knockout, was not observed. This puzzle is resolved by theoretical considerations of the Thomas-Ehrman shift, which also suggests that a previously reported 3471-keV state in 24Si is, in fact, the (0+2) level with one of the largest experimental mirror-energy shifts ever observed.This Rapid Communication was supported by the National Science Foundation (NSF) under Grants No. PHY-1102511 and No. PHY-1565546, by the DOE National Nuclear Security Administration through the Nuclear Science and Security Consortium, under Award No. DE-NA0003180, and by the Department of Energy, Office of Nuclear Physics, under Grants No. DE-FG02-08ER41556 and No. DE-SC0020451. J.A.T acknowledges support from the Science and Technology Facilities Council (U.K.) Grant No. ST/L005743/1. B.A.B. acknowledges support from NSF Grant No. PHY181185

Distinct genetic influences on grammar and phonological short-term memory deficits: evidence from 6-year-old twins.

Children with language impairments have limitations of phonological short-term memory (STM) and have distinctive problems with certain aspects of grammar. Both deficits have been proposed as phenotypic markers of heritable language impairment. We studied 173 twin pairs, selected to be over-representative of children with risk of developmental language impairment, using a battery of standardized language and intelligence tests, a test of nonword repetition to index phonological STM and two elicitation tasks to assess use of verb tense marking. As predicted, the phonological STM and the verb tense measures both discriminated children with risk of language impairment from low risk children, and DeFries-Fulker analysis showed that impairments on both tasks were significantly heritable. However, there was minimal phenotypic and etiological overlap between the two deficits, suggesting that different genes are implicated in causing these two kinds of language difficulty. From an evolutionary perspective, these data are consistent with the view that language is a complex function that depends on multiple underlying skills with distinct genetic origins

Finite-State Computation in Analog Neural Networks: Steps Towards Biologically Plausible Models?

Finite-state machines are the most pervasive models of computation, not only in theoretical computer science, but also in all of its applications to real-life problems, and constitute the best characterized computational model. On the other hand, neural networks ---proposed almost sixty years ago by McCulloch and Pitts as a simplified model of nervous activity in living beings--- have evolved into a great variety of so-called artificial neural networks. Artificial neural networks have become a very successful tool for modelling and problem solving because of their built-in learning capability, but most of the progress in this field has occurred with models that are very removed from the behaviour of real, i.e., biological neural networks. This paper surveys the work that has established a connection between finite-state machines and (mainly discrete-time recurrent) neural networks, and suggests possible ways to construct finite-state models in biologically plausible neural networks