An Epidemiological Study of Listeria Monocytogenes Using Virulence, Agglutination, and Agglutinin Adsorption Techniques

The serological characterization of Listeria monocytogenes apparently began with the work by Seastone, who determined that a close serological relationship existed between cultures collected from humans and animals. Schultz et al. and Julianelle et al. later suggested that two serological types existed that could be connected to the origin of the strain. These initial studies were expanded by the work of Paterson, who studied the antigenic structure of Listeria monocytogenes using agglutination and adsorption techniques. Paterson studied somatic and flagellar antigens. The somatic antigens were prepared by growing bacteria on 1% glucose agar at 37°C for 18 h, removed with and suspended in sterile saline. The flagella were destroyed by heating the suspension to 100°C and maintaining this temperature for two hours. Bacteria to be used with intact flagellar antigens were grown in a 1% glucose broth at 25°C for 18 h, after which time the cells were formalin killed. These suspensions were used for the inoculation of the rabbits, tube agglutinations, and reciprocal adsorptions. Paterson divided the genus Listeria into four different serotypes on the basis of their flagellar and somatic antigens. Serotypes 1, 3, and 4 were differentiated on the basis of their somatic antigens; and serotype 2 was differentiated by its flagellar antigens. Paterson\u27s antigenic scheme of Listeria has survived numerous tests and exists in an expanded form with the additions made by Seeliger and Donker-Voet. Serotypes 1 and 4 are the predominant isolates recovered from susceptible vertebrates. These are further divided on the basis of clinical manifestations of the following four animal groups: ruminants, monogastric animals, fowl, and humans. Either localized encephalitis or meningoencephalitis is a characteristic feature of infection in ruminants, while the typical manifestation in monogastric animals is septicemia accompanied by hepatic necrosis. Septicemia is also a characteristic feature of infection in fowl, but in this group, it is associated with myocardial degeneration. Septicemia with associated meningitis or meningoencephalitis is associated with septicemia in human infections. Abortions and other perinatal infections can occur in all mammals, including humans. Clinical manifestations are not effected by the changing pattern of predominance among the two prevalent serotypes 1 and 4

Equiangular tight frames and fourth root seidel matrices

AbstractIn this paper we construct complex equiangular tight frames (ETFs). In particular, we study the grammian associated with an ETF whose off-diagonal entries consist entirely of fourth roots of unity. These ETFs are classified, and we also provide some computational techniques which give rise to previously undiscovered ETFs

Amphibians and Reptiles Captured in Drift Fences in Northwest Wisconsin Pine Barrens

Drift fence surveys were initiated by the Wisconsin Department of Natural Resources (WDNR) in the Crex Meadows Wildlife Area (CMWA) in 1993. Systematic drift fence trapping of amphibians and reptiles in the northwest pine barrens was conducted in a 1996- 97 cooperative effort by the WDNR, the U.S. Forest Service (USFS), and the Great Lakes Indian Fish and Wildlife Commission (GLIFWC). Drift fences were operated in four managed barrens properties, the CMWA, Namekagon Barrens Wildlife Area (NBWA), the Douglas County Wildlife Area (DCWA), and the Moquah Barrens Wildlife Area (MBWA). Eighteen amphibian and reptile species (four salamanders, eight anurans, one turtle, one lizard, four snakes) were captured in ten drift fences in the Northwest Wisconsin Pine Barrens. Fourteen species were captured in the CMWA. The most common species were chorus frogs (Pseudacris triseriata ssp.), wood frogs (Rana sylvatica), and northern spring peepers (P. c. crucifer). The relative abundance of the amphibians and reptiles captured, expressed as mean 1996-97 catch per effort, did not differ between the four managed properties, but species composition did. Only three species were common to all four properties, the blue-spotted salamander (Ambystoma laterale), the eastern American toad (Bufo a. americanus), and the spring peeper. The most likely reason that species composition differs is that the Northwest Wisconsin Pine Barrens is an ecotone for amphibian and reptile species of the western prairies (e.g. tiger salamanders, Ambystoma t. tigrinum) and species of the eastern forests (e.g. spotted salamanders, A. maculatum). All but three tiger salamanders were captured in the southwesternmost property (CMWA) whereas the spotted salamander was captured only in the northeastern-most property (MBWA). Annual variation in CMWA catch/effort rates occurred in total amphibians and reptiles and individual species captured. Total April-May precipitation did not appear to support the catch/effort variation from year to year. However, when broken down into five-day periods, increased catch/effort rates were significantly correlated to precipitation increases, but not to changes in temperature. Timing and amount of precipitation within the breeding season may have impacted herptile movements in the CMWA