Distance to the Nearest Stable Metzler Matrix

This paper considers the non-convex problem of finding the nearest Metzler matrix to a given possibly unstable matrix. Linear systems whose state vector evolves according to a Metzler matrix have many desirable properties in analysis and control with regard to scalability. This motivates the question, how close (in the Frobenius norm of coefficients) to the nearest Metzler matrix are we? Dropping the Metzler constraint, this problem has recently been studied using the theory of dissipative Hamiltonian (DH) systems, which provide a helpful characterization of the feasible set of stable matrices. This work uses the DH theory to provide a block coordinate descent algorithm consisting of a quadratic program with favourable structural properties and a semidefinite program for which recent diagonal dominance results can be used to improve tractability.Comment: To Appear in Proc. of 56th IEEE CD

Dicamptodon and D. ensatus

Number of Pages: 2Integrative BiologyGeological Science

Ambystoma opacum

Number of Pages: 2Integrative BiologyGeological Science

Ambystoma ordinarium

Number of Pages: 2Integrative BiologyGeological Science

Application of a news quality monitoring methodology

This set of case studies has two main purposes Case studies illustrating the usefulness of the quality monitoring framework set out in chapter one of The Future of Quality News Journalism: a cross-continental analysis The material that is produced below is still under development and may be modified when the final draft is produced shortly. a) Introduction This set of case studies has two main purposes. First, to provide examples of how the quality monitoring framework outlined in chapter one might be applied to online news stories of quality mainstream news providers. Second, to provide some representative sample evidence of the quality of the hard news provision of some of the best of the mainstream news providers. This is intended to back up the case for their continuing importance that is made within the bonus chapter (available only online at: HTTP://CLOK.UCLAN.AC.UK/7824) There are several things that it is important to emphasise. First, as chapter one makes clear, the preferred means of quality assessment would be via the kind of expert/professional panels outlined and suggested there. This should enhance the rigour of the evaluative process in so far as several pairs of expert eyes are likely to pick up inconsistencies in the application of that process in a way that would not be possible for one. Given that such panels do not yet exist to apply it and that the purpose here is mainly illustrative, the evaluations have been made by the author alone. That means that they should be treated with greater caution than had they been panel produced, but providing that is remembered it does not detract from their illustrative value. For the purposes of transparency and the need to provide readers with enough information to help them cross-check the judgments for themselves if they so wish, concise sample reasons are provided at the end of each piece as to why the individual quality ratings have been arrive

RNA Turnover: Unexpected Consequences of Being Tailed

In eukaryotic cells, the 3′ poly(A) tails found on mRNA influence their stability and translation. The discovery of a second nuclear poly(A) polymerase complex has fueled a series of reports defining a new and unexpected role for 3′ end poly(A) tails in the nuclear surveillance and turnover of noncoding RNAs and intergenic mRNAs of unknown function

Ambystoma texanum

Number of Pages: 2Integrative BiologyGeological Science