The concept of positional information is central to our understanding of how cells determine their location in a multicellular structure and thereby their developmental fates. Nevertheless, positional information has neither been defined mathematically nor quantified in a principled way. Here we provide an information-theoretic definition in the context of developmental gene expression patterns...

Three solutions to the problem of serial order can be identified: chaining, ordinal and positional theories. Error patterns in serial recall from short-term memory fail to support chaining theories, yet provide unequivocal evidence for positional theories. In a new model of short-term memory, the Start-End Model (SEM), the positions of items in a sequence are coded relative to the start and end...

This paper describes an implementation to compute positional ngram statistics (i.e. Frequency and Mutual Expectation) based on masks, suffix array-based data structures and multidimensional arrays. Positional ngrams are ordered sequences of words that represent continuous or discontinuous substrings of a corpus. In particular, the positional ngram model has shown successful results for the extr...

Languages often single out prominent positions for special consideration, allowing certain elements to appear only in those positions. Often material in the prominent position surfaces faithfully but neutralizes elsewhere (preservation systems), but other systems involve the spreading or migration of features to the prominent position to comply with the positional restriction (overwrite systems...

Recently, several works have analysed the efficiency of photosynthetic complexes in a transient scenario and how that efficiency is affected by environmental noise. Here, following a quantum master equation approach, we study the energy and excitation transport in fully connected networks both in general and in the particular case of the Fenna-Matthew-Olson complex. The analysis is carried out ...

Background: Uterine natural killer (uNK) cells are the most abundant leukocytes in pre-implantation endometrium and early pregnancy deciduas in humans and rodents. They are associated with structural changes in maternal spiral arteries but regulation of their re-cruitment and activation is incompletely understood. The major subpopulation of uNK cells in humans expresses CD56, the neural cell ad...

BACKGROUND The Dix-Hallpike manoeuvre is performed for diagnosis and the Epley manoeuvre used for treatment of posterior canal benign paroxysmal positional vertigo (BPPV). However, musculoskeletal conditions may restrict utility of these manoeuvres. OBJECTIVE The Semont and liberatory manoeuvres are described in this article. These manoeuvres are simple and highly effective for the diagnosis ...