The Scott rank of a countable structure is a measure, coming from the proof of Scott’s isomorphism theorem, of the complexity of that structure. The Scott spectrum of a theory (by which we mean a sentence of Lω1ω) is the set of Scott ranks of countable models of that theory. In ZFC + PD we give a descriptive-set-theoretic classification of the sets of ordinals which are the Scott spectrum of a ...

Telomere length and stability is a biomarker of aging, stress, and cancer. Shortening of telomeres and high level of DNA damages are known to be associated with aging. Telomere shortening normally occurs during cell division in most cells and when telomeres reach a critically short length, DNA damage signaling and cellular senescence can be triggered. The induction of an adaptive response by sp...

Some 40 years ago, Dana Scott proved that every countable Scott set is the standard system of a model of PA. Two decades later, Knight and Nadel extended his result to Scott sets of size ω1. Here, I show that assuming the Proper Forcing Axiom (PFA), every proper Scott set is the standard system of a model of PA. I define that a Scott set X is proper if it is arithmetically closed and the quotie...

This study aimed at finding features of collocational deviations in the translations of Tuesdays with Mor- rie. In this direction, categories of collocations and collocational clashes, as well as causes of collocation- al clashes were explored. The present work investigated five Persian translations of the novel. All the books were examined completely and all possible collocational clashes were...