Mendel, 150 years on

Mendel's paper 'Versuche über Pflanzen-Hybriden' is the best known in a series of studies published in the late 18th and 19th centuries that built our understanding of the mechanism of inheritance. Mendel investigated the segregation of seven gene characters of pea (Pisum sativum), of which four have been identified. Here, we review what is known about the molecular nature of these genes, which encode enzymes (R and Le), a biochemical regulator (I) and a transcription factor (A). The mutations are: a transposon insertion (r), an amino acid insertion (i), a splice variant (a) and a missense mutation (le-1). The nature of the three remaining uncharacterized characters (green versus yellow pods, inflated versus constricted pods, and axial versus terminal flowers) is discussed.

A preference-based semantics for CTD reasoning

In [8] the authors developed a logical system based on the definition of a new non-classical connective ⊗ capturing the notion of reparative obligation. The system proved to be appropriate for handling well-known contrary-to-duty paradoxes but no model-theoretic semantics was presented. In this paper we fill the gap and define a suitable possible-world semantics for the system for which we can prove soundness and completeness. The semantics is a preference-based non-normal one extending and generalizing semantics for classical modal logics.

Mortality Rate: 150 People Died Daily Artworks

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