Penicillinase-producing strains of Staphylococcus aureus are transformed into stable L colonies by 70 to 100 subcultures on methicillin-containing medium with a suitable high osmolarity. During transformation, the penicillinase activity is lost. This loss in activity is not the result of only the penicillinase-negative mutants transforming to L colonies. If unstable L colonies are filtered thro...

The problem is studied of testing for stability a class of real polynomials in which the coefficients depend on a number of variable parameters in a multilinear way. We show that the testing for real unstable roo& can be achieved by examining the stability of a finite number of comer polynomials (obtained by setting parameters at their extreme values), while checking for unstable complex'rwts n...

Urocanic acid, produced by the nonoxidative deamination of L-histidine, has been demonstrated as the first intermediate in the degradation of this amino acid in liver (l-6) and in microorganisms (7-9). The subsequent enzymatic degradation of urocanic acid yields ol-r-formamidinoglutaric acid (10-13). The present paper describes the enzymatic formation of an unstable intermediate in this reactio...

We study the stability of laminar wakes past three-dimensional rectangular prisms. The width-to-height ratio is set to $W/H=1.2$ , while length-to-height $1/6< L/H<3$ covers a wide range geometries from thin plates elongated Ahmed bodies. First, global linear analysis yields series pitchfork and Hopf bifurcations: (i) at lower Reynolds numbers $Re$ two stationary modes, $A$ $B$ become uns...

OBJECTIVE To determine the differences in the inflammatory status between diabetic and non-diabetic patients and to evaluate the usefulness of C reactive protein, fibrinogen, and leucocyte count as predictors of death in diabetic patients with unstable coronary disease. DESIGN Nested case-control comparisons of the inflammatory status between diabetic and non-diabetic patients. Prospective co...

Existence and uniqueness theorems for unstable manifolds are well-known. Here we prove certain refinements. Let f : (C, 0) → C be a germ of an analytic diffeomorphism, whose derivative Df(0) has eigenvalues λ1, . . . , λn such that |λ1| ≥ · · · ≥ |λk| > |λk+1| ≥ · · · ≥ |λn|, with |λk| > 1. Then there is a unique k-dimensional invariant submanifold whose tangent space is spanned by the generali...

The loss of enzyme activity during the process of purification is a major obstacle when unstable enzymes are used. Douzou and co-workers introduced the idea of using chromatography at subzero temperature in aqueous/organic solvent systems (Balny et al.. 1975). In the present paper we describe the apparatus and a method of using an aqueous/ organic solvent system to purify unstable enzymes at su...