Domain Representable Spaces Defined by Strictly Positive Induction

Recursive domain equations have natural solutions. In particular there are domains defined by strictly positive induction. The class of countably based domains gives a computability theory for possibly non-countably based topological spaces. A $qcb_{0}$ space is a topological space characterized by its strong representability over domains. In this paper, we study strictly positive inductive definitions for $qcb_{0}$ spaces by means of domain representations, i.e. we show that there exists a canonical fixed point of every strictly positive operation on $qcb_{0}$ spaces.Comment: 48 pages. Accepted for publication in Logical Methods in Computer Scienc

Biochemical Purification and Functional Analysis of Complexes between the G-Protein Subunit Gβ5 and RGS Proteins

Regulator of G-protein signaling (RGS) proteins of the R7 subfamily (RGS6, 7, 9, and 11) contain a unique Gγ-like (GGL) domain that enables their association with the G-protein β subunit Gβ5. The existence of these complexes was demonstrated by their purification from native tissues as well as by reconstitution in vitro. According to pulse–chase analysis, Gβ5 and RGS7 monomers undergo rapid proteolytic degradation in cells, whereas the dimer is stable. Studies of the functional role of Gβ5–RGS dimers using GTPase activity, ion channel, and calcium mobilization assays showed that, similarly to other RGS proteins, they can negatively regulate G-protein-mediated signal transduction. Protein–protein interactions involving the Gβ5–RGS7 complex can be studied in cells using fluorescence resonance energy transfer utilizing Gβ5, RGS, and Gα subunits fused to the cyan and yellow versions of green fluorescent protein

Arterial-Venous Perfusion Without Anticoagulation to Reverse Accidental Hypothermia

To investigate a means of rewarming individuals suffering from accidental hypothermia, five Yucatan swine were topically cooled to a core body temperature of 30#x00B0;C. No heparin or any other means of anticoagulation was administered. An extracorporeal circuit consisting of polyvinylchloride tubing, a Bio-Pump and an external stainless steel heat exchanger was utilized and primed with an albuminized Ringers solution. An arterial-venous circuit was employed with oxygenation being provided by the animals' lungs. A series of aliquots of blood were taken and analyzed for coagulation prior to cannulation, after stabilization of blood flows, at a rectal rewarming temperature of 32°C and post-decannulation. All subjects were effectively rewarmed to 34°C, with a mean perfusion time of 64.8 ± 8.5 minutes. Coagulation parameters showed very little alteration from the control values taken: PT (11.9 ± .5), PTT (16.0 ± .9), platelet count (456.0 ± 105.6) and normal fibrinogen levels. Necropsy examination revealed only minimal clot formation within either the extracorporeal circuit or the animals' vascular system. Our results support the hypothesis that circulatory assistance and ultimately, extracorporeal circulation may be possible without anticoagulation