Search results for "formal"

Vuorovaikutusosaaminen ja sen kehittyminen tutkijoiden työssä

2014

Rematrice o filatrice? Donne in un’economia di frontiera (Isole Eolie, inizio dell’Ottocento)

2018

The article explores women’s economic agency in the “border economies” of Mediterranean ports and islands, focusing on the case of Stromboli, in the Sicilian Aeolian Archipelago, in the first half of the nineteenth century. The position of women in the public and the private sphere and the lack of relevant contemporary socio-professional categories makes it difficult to identify their activities, although they are crucial to the understanding of coastal societies. The paper stresses the importance of women’s full involvement in the typical pluriactivity of such communities, combining trade with agriculture and seafaring. In Stromboli, travelers’ reports, notarial and judicial sources show a…

Desymmetrization of Prochiral Cyclobutanones via Nitrogen Insertion: A Concise Route to Chiral γ‐Lactams

2021

Abstract Asymmetric access to γ‐lactams is achieved via a cyclobutanone ring expansion using widely available (1S,2R)‐1‐amino‐2‐indanol for chiral induction. Mechanistic analysis of the key N,O‐ketal rearrangement reveals a Curtin–Hammett scenario, which enables a downstream stereoinduction (up to 88:12 dr) and is corroborated by spectroscopic, crystallographic, and computational studies. In combination with an easy deprotection protocol, this operationally simple sequence allows the synthesis of a range of optically pure γ‐lactams, including those bearing all‐carbon quaternary stereocenters. In addition, the formal synthesis of drug molecules baclofen, brivaracetam, and pregabalin further …

On the Amount of Nonconstructivity in Learning Recursive Functions

2011

Nonconstructive proofs are a powerful mechanism in mathematics. Furthermore, nonconstructive computations by various types of machines and automata have been considered by e.g., Karp and Lipton [17] and Freivalds [11]. They allow to regard more complicated algorithms from the viewpoint of much more primitive computational devices. The amount of nonconstructivity is a quantitative characterization of the distance between types of computational devices with respect to solving a specific problem. In the present paper, the amount of nonconstructivity in learning of recursive functions is studied. Different learning types are compared with respect to the amount of nonconstructivity needed to lea…