Pacioli and humanism: pitching the text in Summa Arithmetica

Despite the wide cross-disciplinary influence of Fra’ Luca Pacioli’s Summa de Arithmetica, Geometria, Proportioni et Proportionalita (Summa), it has been criticized as being both difficult to read and written in a mixture of bad Italian and bad Latin; but, paradoxically, intellectuals of Pacioli’s day praised the style of writing in Summa. Can both viewpoints be correct? The answer to this question is sought by identifying what may have inspired Pacioli to write Summa in the manner he did. In doing so, the article considers the times in which he lived and, in particular, the impact that Renaissance Humanism and Humanist Education may have had upon his writing style. The article finds both views were correct in their own timeframes and contexts and that Pacioli’s writing style was both an appropriate one with which to address a contemporary merchant society and one which would impress and gain the approval of his fellow humanist educators and patrons

The market for Luca Pacioli's 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

U-Pb geochronology of the Lime Hill gneissic complex, Cape Breton Island, Nova Scotia

Low-grade metasedimentary rocks of Late Proterozoic age in the Bras d'Or Terrane of Cape Breton Island contain small areas of gneissic rocks which were previously undated. New U-Pb data indicate that the Lime Hill gneissic complex is the product of an Early Cambrian intrusive/metamorphic event Two intrusions at Lime Hill give similar ages which indicate that emplacement and deformation of foliated tonalitic orthogneiss were followed very quickly by intrusion of massive granitic dykes at about 540 to S4S Ma. U-Pb analyses of metamorphic monazite from the Lime Hill paragneiss indicate that these rocks last cooled through the closure temperature of the U-Pb system for monazite (650-700°C) at about 549 Ma. All zircon fractions analyzed from the tonalitic orthogneiss and granitic dyke contain older inherited zircons which yield an apparent age range of at least 1.4 to 23 Ga. The presence of an inherited monazite component may suggest that the rocks have been affected by an older metamorphic event and are in fact older than the Malagawatch Formation, as suggested by published ore lead isotopic values. RÉSUMÉ Des roches métasédimentaires faiblement meétamorphisees d'âge protérozolque tardif et faisant partie de la Lanière de Bras d'Or (ile du Cap Breton), renferment des Hots de roches gneissiques dont l'âge n'avait pas encore été déterminé. De nouvelles données U-Pb indiquent que le complexe gneissique de Lime Hill est le résultat d'un épisode intrusif ou métamorphique datant du deimt du Cambrien. A Lime Hill, deux intrusions ont produit des âges semblables qui montrent que l'emplacement et la déformation d'un orthogneiss tonalitique furent suivis très rapidement par l'intrusion de dykes granitiques massifs, il y a environ 540 à 545 Ma. Des analyses U-Pb d'une monazite métamoiphique provenant du paragneiss de Lime Hill indiquent que le demier réfroidissement de ces roches en deca de la température de clôture du système U-Pb pour la monazite, i.e. de 650 à 700°C, eût lieu vers 549 Ma. Toutes les portions de zircons extraites de l'orthogneiss tonalitique et du dyke granitique comprennent des zircons remaniés qui donnent un âge apparent dont la gamme s'étend de 1.4 à 2.3 Ga. La présence d'une composante de monazite remaniée semble suggèrer que les roches ont subi un épisode antérieur de métamorphisme, et indiquer que les roches sont en réalité plus vieilles que la Formation de Malagawatch, tel que suggèré par les valeurs publiées des isotopes du plomb du minéral. [Traduit par le journal

Strategic manoeuvres and impression management: communication approaches in the case of a crisis event

This historical study examines the actions of the Australian former asbestos company, James Hardie, when faced with a potentially ruinous corporate scandal between 2001 and 2007. The company became vilified as public awareness grew of the damage to public health its use of asbestos had caused. In response, it set- up a knowingly underfunded compensation fund supported by a strategy of misinformation and denial. Its actions are analysed using Oliver’s typology of strategic responses and theories of crisis management and crisis communications, providing insights into the company’s motivations for adopting strategies that took it to the brink of financial collaps

The generation of influenza-specific humoral responses is impaired in ST6Gal I-deficient mice.

Posttranslational modification of proteins, such as glycosylation, can impact cell signaling and function. ST6Gal I, a glycosyltransferase expressed by B cells, catalyzes the addition of alpha-2,6 sialic acid to galactose, a modification found on N-linked glycoproteins such as CD22, a negative regulator of B cell activation. We show that SNA lectin, which binds alpha-2,6 sialic acid linked to galactose, shows high binding on plasma blasts and germinal center B cells following viral infection, suggesting ST6Gal I expression remains high on activated B cells in vivo. To understand the relevance of this modification on the antiviral B cell immune response, we infected ST6Gal I(-/-) mice with influenza A/HKx31. We demonstrate that the loss of ST6Gal I expression results in similar influenza infectivity in the lung, but significantly reduced early influenza-specific IgM and IgG levels in the serum, as well as significantly reduced numbers of early viral-specific Ab-secreting cells. At later memory time points, ST6Gal I(-/-) mice show comparable numbers of IgG influenza-specific memory B cells and long-lived plasma cells, with similarly high antiviral IgG titers, with the exception of IgG2c. Finally, we adoptively transfer purified B cells from wild-type or ST6Gal I(-/-) mice into B cell-deficient (microMT(-/-)) mice. Recipient mice that received ST6Gal I(-/-) B cells demonstrated reduced influenza-specific IgM levels, but similar levels of influenza-specific IgG, compared with mice that received wild-type B cells. These data suggest that a B cell intrinsic defect partially contributes to the impaired antiviral humoral response

Quantum gates with topological phases

We investigate two models for performing topological quantum gates with the Aharonov-Bohm (AB) and Aharonov-Casher (AC) effects. Topological one- and two-qubit Abelian phases can be enacted with the AB effect using charge qubits, whereas the AC effect can be used to perform all single-qubit gates (Abelian and non-Abelian) for spin qubits. Possible experimental setups suitable for a solid state implementation are briefly discussed.Comment: 2 figures, RevTex