Market for Luca Pacioli\u27s Summa Arithmetica

This paper looks at an aspect of Luca Pacioli and his Summa Arithmetica that has not previously been explored in detail the market for which he wrote the book. In order to do so, it follows a path identified by two clues in the bookkeeping treatise as to the nature of this market that modern eyes, unaware of how life was in late 15th century Italy, have missed. After discussing the curriculum taught in schools at that time, this paper considers a range of possible markets for which the book may have been written. The paper concludes that it was written primarily for, and sold mainly to, merchants who used the book as a reference text, as a source of pleasure from the mathematical puzzles it contained, and as an aid for the education of their sons

Pacioli\u27s forgotten book: The Merchant\u27s Ricordanze

Double entry bookkeeping emerged by the end of the 13th century and was adopted by, for example, the Datini of Prato during the 1380s. In the transition from single to double entry evident in the Datini Archives, initially accounting records were kept in an account book called a Ricordanze. Record books of this name were typical of Tuscany and, when such books were first used in Tuscany, businessmen began to use them also as a form of personal diary and autobiographical record. Others not in business followed suit and maintained purely personal biographical diaries of the same name. For those in business, the Ricordanze thus developed into a hybrid: partly autobiography and personal and, partly, a place to record matters relating to his business, including details of transactions and of other matters he did not wish to forget, such as promises, obligations, and conditional agreements. As revealed in the Datini archives for the 14th and 15th centuries, use of a Ricordanze for this purpose was discontinued in the accounting system and the book was replaced with another called a Memoriale, which contained details of all business transactions. By the time Pacioli wrote the first published description of double entry bookkeeping, the Memoriale was identified as one of the three principal account books of that system. The others were the Giornale [journal] and the Quaderno [ledger]. However, largely unnoticed by accounting scholars, towards the end of his treatise, Pacioli also describes another book that merchants would be wise to keep\u27: a Ricordanze. Not a personal Ricordanze nor a hybrid personal plus business Ricordanze, nor a version of a Memoriale. Pacioli,s Ricordanze was intended to serve a very specific purpose: it was a book dedicated to maintaining a record of things that should not be forgotten. As such, it was intended to provide an extra layer of managerial control over the affairs of the merchant beyond that provided by the double entry system. This paper considers the role of Pacioli\u27s Ricordanze, of the records that may be maintained within it, discusses the merits of maintaining a record book of this type, and questions why such a clearly useful device does not appear to have been adopted even though it was described in the same treatise which led to the universal adoption of double entry bookkeeping

The Multifragmentation Freeze--Out Volume in Heavy Ion Collisions

The reduced velocity correlation function for fragments from the reaction Fe + Au at 100 A~MeV bombarding energy is investigated using the dynamical--statistical approach QMD+SMM and compared to experimental data to extract the Freeze--Out volume assuming simultaneous multifragmentation.Comment: 8 pages; 3 uuencoded figures available with figures command, LateX, UCRL-J-1157

Generation of Intrinsic Vibrational Gap Modes in Three-Dimensional Ionic Crystals

The existence of anharmonic localization of lattice vibrations in a perfect 3-D diatomic ionic crystal is established for the rigid-ion model by molecular dynamics simulations. For a realistic set of NaI potential parameters, an intrinsic localized gap mode vibrating in the [111] direction is observed for fcc and zinc blende lattices. An axial elastic distortion is an integral feature of this mode which forms more readily for the zinc blende than for the fcc structure. Molecular dynamics simulations verify that in each structure this localized mode may be stable for at least 200 cycles.Comment: 5 pages, 4 figures, RevTeX, using epsf.sty. To be published in Phys. Rev. B. Also available at http://www.msc.cornell.edu/~kiselev

quasiharmonic equations of state for dynamically-stabilized soft-mode materials

We introduce a method for treating soft modes within the analytical framework of the quasiharmonic equation of state. The corresponding double-well energy-displacement relation is fitted to a functional form that is harmonic in both the low- and high-energy limits. Using density-functional calculations and statistical physics, we apply the quasiharmonic methodology to solid periclase. We predict the existence of a B1--B2 phase transition at high pressures and temperatures

TECHNICAL ADVANCE: Indel arrays: an affordable alternative for genotyping

SummaryNatural variation and induced mutations are important resources for gene discovery and the elucidation of genetic circuits. Mapping such polymorphisms requires rapid and cost‐efficient methods for genome‐wide genotyping. Here we report the development of a microarray‐based method that assesses 240 unique markers in a single hybridization experiment at a cost of less than US$50 in materials per line. Our genotyping array is built with 70‐mer oligonucleotide elements representing insertion/deletion (indel) polymorphisms between the Arabidopsis thaliana accessions Columbia‐0 (Col) and Landsberg erecta (Ler). These indel polymorphisms are recognized with great precision by comparative genomic hybridization, eliminating the need for array replicates and complex statistical analysis. Markers are present genome‐wide, with an average spacing of approximately 500 kb. PCR primer information is provided for all array indels, allowing rapid single‐locus inquiries. Multi‐well chips allow groups of 16 lines to be genotyped in a single experiment. We demonstrate the utility of the array for accurately mapping recessive mutations, RIL populations and mixed genetic backgrounds from accessions other than Col and Ler. Given the ease of use of shotgun sequencing to generate partial genomic sequences of unsequenced species, this approach is readily transferable to non‐model organisms

Assessment of ion kinetic effects in shock-driven inertial confinement fusion implosions using fusion burn imaging

The significance and nature of ion kinetic effects in D3He-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, NK) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurements of the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (NK3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects

Accounting students' IT applicaton skills over a 10-year period

This paper reports on the changing nature of a range of information technology (IT) application skills that students declare on entering an accounting degree over the period from 1996 to 2006. Accounting educators need to be aware of the IT skills students bring with them to university because of the implications this has for learning and teaching within the discipline and the importance of both general and specific IT skills within the practice and craft of accounting. Additionally, IT skills constitute a significant element within the portfolio of employability skills that are increasingly demanded by employers and emphasized within the overall Higher Education (HE) agenda. The analysis of students' reported IT application skills on entry to university, across a range of the most relevant areas of IT use in accounting, suggest that their skills have continued to improve over time. However, there are significant differential patterns of change through the years and within cohorts. The paper addresses the generalizability of these findings and discusses the implications of these factors for accounting educators, including the importance of recognising the differences that are potentially masked by the general increase in skills; the need for further research into the changing nature, and implications, of the gender gap in entrants' IT application skills; and the low levels of entrants' spreadsheet and database skills that are a cause for concern