in this work, we investigate the transfer of some homological properties from a ring $r$ to its amalgamated duplication along some ideal $i$ of $r$ $rbowtie i$, and then generate new and original families of rings with these properties.

for a ring endomorphism $alpha$ and an $alpha$-derivation $delta$, we introduce a concept, so called skew $pi$-armendariz ring, that is a generalization of both $pi$-armendariz rings, and $(alpha,delta)$-compatible skew armendariz rings. we first observe the basic properties of skew $pi$-armendariz rings, and extend the class of skew $pi$-armendariz rings through various ring extensions. we nex...

Michelle McCoy is the Bibliographic Assistant at DePaul University Special Collections and Archives and will graduate with her MLIS from Dominican University in spring 2009. She has undergraduate degrees in Art and Education. ©Michelle McCoy The collaborative effort between two Special Collections librarians and a history professor at DePaul University led to a quarter-long undergraduate projec...

McCoy cells treated in six different ways, in addition to untreated cells, were compared to determine which gave rise to the largest number of Chlamydia trachomatis inclusions when tested with a laboratory-passaged strain. The same batch of cells was treated by irradiation, preinoculation exposure to cytochalasin B or 5-iodo-2'-deoxyuridine, and postinoculation exposure to cycloheximide, hydroc...

This study compared the direct visualisation of elementary bodies in urogenital smears by the direct immunofluorescence test with the isolation of Chlamydia trachomatis in McCoy cell cultures treated with cytochalasin B. C trachomatis was isolated from 41 (16.4%) of 250 unselected specimens in McCoy cell cultures treated with cytochalasin B. Of the 41 culture positive specimens 37 (90%) were di...

Iterative theories, which were introduced by Calvin Elgot, formalise potentially infinite computations as unique solutions of recursive equations. One of the main results of Elgot and his coauthors is a description of a free iterative theory as the theory of all rational trees. Their algebraic proof of this fact is extremely complicated. In our paper we show that by starting with ‘iterative alg...

In this article we obtain some exact results for the 2D Ising model with a general boundary magnetic field and for a finite size system, by an alternative method to that developed by B. McCoy and T.T. Wu. This method is a generalization of ideas from V.N. Plechko presented for the 2D Ising model in zero field, based on the representation of the Ising model using a Grassmann algebra. In this way...

An isolation technique for Chlamydia trachomatis using McCoy cells is described. In contrast to earlier techniques employing such cells, no pretreatment of the cells was used. The glutarimide antibiotic cycloheximide was added to the culture medium used for incubating the cells after infection. Cycloheximide was used at concentrations that depressed, but did not completely inhibit, the metaboli...

By using representative strains of Chlamydia trachomatis serotypes, the efficacy of substituting fetal bovine serum with newborn calf serum for the isolation of this organism in tissue culture was examined. The criteria used were the quality and quantity of the iodine-stained cytoplasmic inclusions and the characteristics of the McCoy cells. Complete substitution of fetal bovine serum with newb...