8,824 research outputs found
Genetic Recombination in Bacteriophage {varphi}X174
Genetic recombination in bacteriophage {varphi}X174 usually takes place early in the infection process and involves two parental replicative form (double-stranded) DNA molecules. The host recA protein is required; none of the nine known {varphi}X174 cistron products is essential. The products of a single recombination event are nonreciprocal and asymmetric. Typically, only one of the parental genotypes and one recombinant genotype are recovered from a single cell. An alternative, less efficient recombination mechanism which requires an active {varphi}X174 cistron A protein is observed in the absence of the host recA gene product
Daze fasteners
A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces has line element extensions that pass through a common point
The Trouble with Bulls: The Cacce dei Tori in Early Modern Venice
The city of Venice has been historiographically identified with festival. Venetians
staged regular symbolic enactments of the city’s piety, beauty, unity, military valour,
connection with the sea, and sense of justice, usually exploiting Venice’s public
squares, boats, bridges, and canals to give these occasions a unique character. One
festival, however, the cacce dei tori or baiting of bulls, celebrated none of these
virtues and had nothing to do with the sea. Usually found in cities with strong
feudal and economic ties to the countryside, such events would seem out of place
in a city with no such ties and an impractical environment for large animals. The
roots of the cacce dei tori, however, lay more in Venice’s intense neighbourhood
and factional rivalries than in urban-rural tensions.Sur le plan historiographique, on identifie la ville de Venise aux festivals. Les
Vénitiens faisaient régulièrement des mises en scène symboliques de la piété, de la
beauté, de l’unité, de la vaillance militaire, du lieu avec la mer et du sens de la
justice de la ville, exploitant habituellement les places publiques, les bateaux, les
ponts et les canaux de Venise pour conférer un cachet unique à ces occasions. Un
festival, toutefois, le cacce dei tori, ou l’appâtage des taureaux, ne célébrait aucune
de ces vertus et n’avait rien à voir avec la mer. De tels événements, qui se déroulaient
normalement dans des villes ayant de solides liens féodaux et économiques
avec la campagne, paraîtraient incongrus dans une ville ne présentant aucuns liens
de la sorte et offrant un milieu inhospitalier pour des animaux de grande taille. Le
cacce dei tori tire cependant davantage ses racines des fortes rivalités entre les
quartiers et les factions de Venise que des tensions urbano-rurales
Early and late complications of bariatric operation.
Weight loss surgery is one of the fastest growing segments of the surgical discipline. As with all medical procedures, postoperative complications will occur. Acute care surgeons need to be familiar with the common problems and their management. Although general surgical principles generally apply, diagnoses specific to the various bariatric operations must be considered. There are anatomic considerations which alter management priorities and options for these patients in many instances. These problems present both early or late in the postoperative course. Bariatric operations, in many instances, result in permanent alteration of a patient\u27s anatomy, which can lead to complications at any time during the course of a patient\u27s life. Acute care surgeons diagnosing surgical emergencies in postbariatric operation patients must be familiar with the type of surgery performed, as well as the common postbariatric surgical emergencies. In addition, surgeons must not overlook the common causes of an acute surgical abdomen-acute appendicitis, acute diverticulitis, acute pancreatitis, and gallstone disease-for these are still among the most common etiologies of abdominal pathology in these patients
Cryogenic Insulation System
This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system
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