There will be a special issue of the Journal of Logic and Computation arising from Logic Colloquium 2009 and the satellite meeting Workshop in Computability Theory 2009, held in Sofia in July-August 2009. Submission is by invitation only.

The deadline for receiving completed articles is: October 16th, 2009.

This special issue was sent to the publisher on August 20, 2010

Enquiries from authors, and articles for refereeing, should be sent to the coordinating editor Alexandra Soskova, or to the appropriate guest editor ( = Barry Cooper, = Andrea Sorbi, = Alexandra Soskova).

Provisional contents Author(s) Title Received Pages Status Marat Arslanov Model-Theoretic Properties of the n-C.E. Degrees Oct. 29, 2009 12 Final version George Barmpalias Compactness Arguments with Effectively Closed Sets for the Study of Relative Randomness Oct. 26, 2009 13 Final version George Barmpalias and Andre Nies Low Upper Bounds in the Turing Degrees Revisited Nov. 05, 2009 7 Final version Laurent Bienvenu, Rupert Hölzl, Thorsten Kräling and Wolfgang Merkle Separations of Non-Monotonic Randomness Notions Oct. 07, 2009 22 Final version Angel V. Ditchev Least Enumerations of Partial Structures Oct. 12, 2009 25 Final version Marat Faizrahmanov and Iskander Kalimullin Turing and Enumeration Jumps in the Ershov Hierarchy Oct. 16, 2009 9 Final version Andrey Frolov Low Linear Orderings Oct. 19, 2009 13 Final version Andrey Frolov, Valentina Harizanov, Iskander Kalimullin, Oleg Kudinov and Russell Miller Spectra of Highn and Nonlown Degrees Oct. 16, 2009 35 Final version Hristo Ganchev and Mariya Soskova Embedding Distributive Lattices in the Σ20 Enumeration Degrees Nov. 6, 2009 13 Final version Alexander Gavryushkin On Constructive Models of Theories with Linear Rudin-Keisler Ordering Oct. 14, 2009 18 Final version Charles Harris Noncuppable Enumeration Degrees via Finite Injury Oct. 16, 2009 24 Final version Iskander Kalimullin Algorithmic Reducibilities of Algebraic Structures Nov. 02, 2009 18 Final version Andrew Lewis Properties of the Jump Classes Oct. 28, 2009 10 Final version Antonio Montalban Counting the Back-And-Forth Types Oct. 19, 2009 18 Final version Anthony Morphett Prompt Enumerations and Relative Randomness Nov. 10, 2009 18 Final version Dimiter Skordev, Andreas Weiermann and Ivan Georgiev M2-Computable Real Numbers Oct. 15, 2009 28 Final version Mariya I. Soskova and Ivan N. Soskov Embedding Countable Partial Orderings in the Enumeration Degrees and the ω-Enumeration Degrees Oct. 15, 2009 25 Final version