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Research about Maryland

Source-linked reports with geographic coverage including Maryland.

At least 415 records · Page 23Linked to original sources
USGS1962

Occurrence of Trypanosoma cruzi in Maryland

During 1954-1960, 2005 mammals of 18 species collected at the Patuxent Wildlife Research Center, Maryland, were examined for trypanosomes. T. cruzi was found in 10 raccoons between October 31 and November 30. Infection occurred in 2 percent of all raccoons sampled, and in 11.3 percent of the 80 raccoons sampled in November. Examination was by direct smears, stained smears and cultures of heart blood. Although, in previous studies, at least two experimentally infected raccoons exhibited extended parasitemia (14 and 8 weeks), no such continuing parasitemia was observed in the natural infections. No trypanosomes were found in any of the other mammals examined.

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USGS1961

Trichomonad infection in mourning doves, Zenaidura macroura, in Maryland

During the 10-year period 1950-1960 the incidence of Trichomonas gallinae among several series of mourning doves shot or trapped in Maryland has varied from zero to 12 1/2 percent. Prior to 1959, all isolations of T. gallinae from doves during such surveys had been from birds with well-developed lesions. In 1959, trichomonads were demonstrated in three of 54 normal hunter-killed doves examined in Howard County. The incidence of trichomonad infection among doves which were submitted to the laboratory because they were obviously diseased was much higher. Of 44 clinically ill doves submitted during the period 1950-1960,25 were found to be infected with T. gallinae. In the Maryland area the incidence of trichomonad infection among mourning doves appears to be low, but when infection does occur it is usually due to a pathogenic strain which produces a typical fatal canker.

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USGS1958

Limestone aquifers of Maryland

Limestone rocks are an important source of ground water in the Piedmont and Appalachian areas of Maryland. The major limestone aquifers are the Cockeysville and Wakefield marbles and the Silver Run, Tomstown, Frederick, Grove, Waynesboro, Elbrook, Conococheague, Beekmantown, Stones River, Tonoloway, Helderberg and Greenbrier formations. Drilled and dug wells and springs are common sources of water supply in the limestone areas. The depths of 298 limestone wells range from 8.7 to 1,800 feet and average about 150 feet. The yields of these wells range from 0.1 to 575 gpm. Specific capacities, or yield per foot of drawdown, range in 137 wells from 0.1 to 43 gpm per foot. Springs are common in the limestone areas and their flow varies widely at different times. Most of the known springs are of the 5th magnitude or lower, and therefore have a mean flow of less than 100 gpm. The quality of water from the limestone aquifers is satisfactory for most purposes, but is commonly hard and slightly alkaline. The limestone aquifers are large essentially untapped ground-water reservoirs whose hydrologic character is only partially understood.

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USGS1958

The isolation and identification of Trypanosoma cruzi from raccoons in Maryland

Five raccoons trapped at Patuxent Research Refuge, Laurel, Maryland, were found to have trypanosomes in the blood which were morphologically indistinguishable from Trypanosoma cruzi on stained smears. The organism grew well in culture. It developed and reproduced in Triatoma protracta, T. infestans, T. phyllosoma , and Rhodnius prolixus . Experimental infections were produced in raccoons, opossums, mice, rats, and monkeys by inoculation of blood, culture, and triatome forms. Typical leishmaniform bodies were found in tissue sections of cardiac muscle fibers from naturally and experimentally infected animals. Cross agglutinations carried out with living cultural forms and rabbit antisera demonstrated a close antigenic relationship between the raccoon trypanosome and T. cruzi (Brazil strain). On the basis of (1) morphology, (2) presence of leishmaniform tissue stages, (3) development in triatomes, (4) infectivity to a variety of mammals, (5) culture characteristics, and (6) cross reactions in serological tests, this parasite is considered conspecific with Trypanosoma cruzi (Chagas, 1909) the causative agent of American human trypanosomiasis.

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USGS1957

Eastern glossy ibis nesting in southeastern Maryland

On June 25, 1956, Don P. Fankhauser and I investigated a large heron colony of mixed species, on Mills Island in Chincoteague Bay, Worcester County, Maryland. Large numbers of American Egrets ( Casmerodius albus ), Snowy Egrets ( Leucophoyx thula ), Louisiana Herons ( Hydranassa tricolor ), Little Blue Herons ( Florida caerulea ), and Black-crowned Night Herons ( Nycticorax nycticorax ) were found, all nesting in a dense grove of young red cedar ( Juniperus virginiana ). Much to our surprise, the colony also included at least two pairs of the Eastern Glossy Ibis ( Plegadis falcinellus ). Four adults of this species were repeatedly observed flying low overhead and frequently perching in nearby tree-tops. In addition, two young ibis, about three-fourths grown, were found. These two birds, still unable to fly, would hop and flutter among the tree branches whenever they were approached too closely. The large white crown patch and the peculiar barred markings of the bill were especially noticeable on both of the young.

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USGS1955

Macracanthorhynchus ingens from raccoons in Maryland

There have been very few published records of the occurrence of the acanthocephalan parasite Macracanthorhynchus ingens (von Linstow, 1897) in North America. Chandler (1942) and Moore (1946) reported 11 o 13 raccoons ( Procyon lotor ) trapped in Angelina County, Texas, infected with these intestinal parasites. From 1 to 90 worms occurred in these animals. Chandler and Melvin (1951), in a study of parasites collected from mammals in Pennsylvania, reported M. ingens common in its usual host, the raccoon, and also found immature worms believed to belong to this species in skunk, Mephitis nigra ; mink, Mustela vision ; fox, Urocyon cineraoargenteus ; and mole, Parascalops breweri . Van Cleave (1953), in a review of North American Acanthocephala, lists the definitive host as raccoon of the States of Texas and Pennsylvania. He further states: “It is thought that the apparent discontinuous distribution of M. ingens is due to incomplete records of its occurrence in intervening states.” Subsequently, Goldberg (1954) reported 5 specimens of M. ingens in one of 14 skunks from Beltsville, Md. This parasite appears to be fairly common in raccoons from Maryland, as indicated by material from two stations in the State. Of 44 intestinal tracts collected during the winter months, 1943-1946, at the Patuxent Research Refuge, laurel, Maryland, 22 (50%) contained M. ingens in their intestines (Ediger, 1950). Numbers of these parasites per host varied from 1 to 125. Since then, additional raccoons from the Patuxent Research refuge have been found infected with M. ingens . The parasite has also been noted in raccoons collected from the Blackwater National Wildlife refuge and surrounding areas, near Cambridge on the eastern shore of Maryland. One raccoon obtained in May, 1950, contained five specimens of M. ingens . In a series of raccoons obtained by V.T. Harris, during the winter months 1950-1951, 32 (37%) of 86 raccoons examined were infected with M. ingens . Intensity varied from 1 to 44 worms per raccoon.

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USGS1952

The foods of fur animals of the Patuxent Research Refuge, Maryland

Approximately 300 digestive tracts of fur animals obtained mostly during the winter trapping season and 560 scats from animals live-trapped on the Patuxent Research Refuge near Laurel, Maryland, were analyzed. The resulting data are summarized and a brief description of the area and important habitat types is given. The animals studied include the raccoon, red fox, gray fox, mink, New York weasel, skunk, opossum, and house cat.

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