The genomic GC contents of both nitrogen-fixing and non-fixing members of eight genera of bacteria are investigated. Analysis by t-tests showed that in the two aerobic general investigated (Aquaspirillum and Vibrio) there is a significantly higher GC content in the nitrogen-fixing members of the genus than in those unable to fix nitrogen, whilst in aerobic genera there is either no GC bias, or ...

For classification problems with ordinal attributes very often the class attribute should increase with each or some of the explanatory attributes. These are called classification problems with monotonicity constraints. Standard classification tree algorithms such as CART or C4.5 are not guaranteed to produce monotone trees, even if the data set is completely monotone. We look at pruning based ...

Proof. Let L/F be an algebraic extension. Let f : L −→ L be a homomorphism fixing F . Recall that field homomorphisms are always injective, it remains to show that it is surjective. Let a ∈ L. As L/F is algebraic, there exists a1, . . . , ad ∈ F such that a satisfy p(x) = x + a1xd−1 + . . .+ ad. Let S = {s ∈ L : p(s) = 0}. As f is a homomorphism fixing the coefficients of the polynomial p(x), i...

Systems of consistent linear equations with symmetric positive semidefinite matrices arise naturally while solving many scientific and engineering problems. In case of a “floating” static structure, the boundary conditions are not sufficient to prevent its rigid body motions. Traditional solvers based on Cholesky decomposition can be adapted to these systems by recognition of zero rows or colum...

In these lectures we describe the construction of a gauge invariant renormalization group equation for pure non-Abelian gauge theory. In the process, a non-perturbative gauge invariant continuum Wilsonian effective action is precisely defined. The formulation makes sense without gauge fixing and thus manifest gauge invariance may be preserved at all stages. In the large N limit (of SU(N) gauge ...

Many optimization problems in queueing theory have functions with integer and real variables. Convexity results for these functions can be obtained by fixing either the integer or the real variable where bounds of the considered function play an important role. Tokgöz, Maalouf and Kumin [11] introduces the concept of mixed convexity for functions with real and integer variables and obtain conve...

A highly efficient bug fixing process and quick release cycles are considered key properties of the open source software development methodology. In this paper, we study the relation between code activities (such as lines of code added per commit), bug fixing activities, and software release dates in a subset of open source projects. To study the phenomenon, we gathered a large data set about t...

1550-7998=20 Diffeomorphism-induced symmetry transformations and time evolution are distinct operations in generally covariant theories formulated in phase space. Time is not frozen. Diffeomorphism invariants are consequently not necessarily constants of the motion. Time-dependent invariants arise through the choice of an intrinsic time, or equivalently through the imposition of time-dependent ...

Seven diazotrophs that grow well under Mo-deficient, N(2)-fixing conditions were isolated from a variety of environments. These isolates fall in the gamma subdivision of the class Proteobacteria and have genes that encode the Mo nitrogenase (nitrogenase 1) and the V nitrogenase (nitrogenase 2). Four of the isolates also harbor genes that encode the iron-only nitrogenase (nitrogenase 3).