Acceptance of the Clark P. Read Mentor Award: The Teague Self Lessons

The transcript of John J. Janovy Jr.\u27s speech upon acceptance of the American Society of Parasitologists\u27 Clark P. Read Mentor Award, 2003

The \u3ci\u3eLeishmania\u3c/i\u3e Years at UNL (Or, My Life as a Cell Biologist, 1966-1981)

Slides for a talk during which Professor Janovy discussed the methods he used in researching Leishmania during the years 1966-1981. Includes lists of references

Review of \u3ci\u3eProtozoology\u3c/i\u3e, 5th ed., by Richard R. Kudo (Thomas, Springfield, 1966)

Review of Protozoology, 5th edition, by Richard R. Kudo, published by Thomas, Springfield, 1966

Community Structure and Seasonal Dynamics of \u3ci\u3eDactylogyrus\u3c/i\u3e spp. (Monogenea) on the Fathead Minnow (\u3ci\u3ePimephales promelas\u3c/i\u3e) from the Salt Valley Watershed, Lancaster County, Nebraska

The gill monogene communities of Pimephales promelas (fathead minnow) in three distinct sites on converging streams were investigated from 2004 to 2006 in three different seasons. Thirty collections of P. promelas were made in southeastern Nebraska along three converging tributaries: Elk Creek (40.88534°N, 96.83366°W), West Oak Creek (40.9082°N, 96.81432°W), and Oak Creek (40.91402°N, 96.770583°W), Lancaster County, Nebraska. In all, 103 P. promelas were collected from Elk Creek, 115 from West Oak Creek, and 78 from Oak Creek and examined for gill monogenes. Among the P. promelas collected, 93.5% were infected with up to three species of Dactylogyrus, including Dactylogyrus simplex Mizelle, 1937, Dactylogyrus bychowskyi Mizelle, 1937, and Dactylogyrus pectenatus Mayes, 1977. Mean intensities at Elk Creek, West Oak Creek, and Oak Creek were 17.6, 22.8, and 25.1, and prevalences 88, 95, and 97%, respectively. At these three sites: (1) P. promelas does not share Dactylogyrus species with Semotilus atromaculatus (creek chub) or Notropis stramineus (sand shiner); (2) fish size and sex are not predictive of Dactylogyrus infection; (3) Dactylogyrus spp. vary (not always predictably) in their seasonal occurrence; (4) populations of Dactylogyrus spp. respond to environmental differences among sites; and (5) the community structure of Dactylogyrus spp. (order of abundance) is independent of environment

Community Structure and Seasonal Dynamics of \u3ci\u3eDactylogyrus\u3c/i\u3e spp. (Monogenea) on the Fathead Minnow (\u3ci\u3ePimephales promelas\u3c/i\u3e) from the Salt Valley Watershed, Lancaster County, Nebraska

The gill monogene communities of Pimephales promelas (fathead minnow) in three distinct sites on converging streams were investigated from 2004 to 2006 in three different seasons. Thirty collections of P. promelas were made in southeastern Nebraska along three converging tributaries: Elk Creek (40.88534°N, 96.83366°W), West Oak Creek (40.9082°N, 96.81432°W), and Oak Creek (40.91402°N, 96.770583°W), Lancaster County, Nebraska. In all, 103 P. promelas were collected from Elk Creek, 115 from West Oak Creek, and 78 from Oak Creek and examined for gill monogenes. Among the P. promelas collected, 93.5% were infected with up to three species of Dactylogyrus, including Dactylogyrus simplex Mizelle, 1937, Dactylogyrus bychowskyi Mizelle, 1937, and Dactylogyrus pectenatus Mayes, 1977. Mean intensities at Elk Creek, West Oak Creek, and Oak Creek were 17.6, 22.8, and 25.1, and prevalences 88, 95, and 97%, respectively. At these three sites: (1) P. promelas does not share Dactylogyrus species with Semotilus atromaculatus (creek chub) or Notropis stramineus (sand shiner); (2) fish size and sex are not predictive of Dactylogyrus infection; (3) Dactylogyrus spp. vary (not always predictably) in their seasonal occurrence; (4) populations of Dactylogyrus spp. respond to environmental differences among sites; and (5) the community structure of Dactylogyrus spp. (order of abundance) is independent of environment

Why We Have Field Stations: Reflections on the Cultivation of Biologists

For a resident of the state of Nebraska, the Cedar Point Biological Station (CPBS), located in scenic limestone bluffs below Kingsley Dam, an earth-filled artificial mountain that impounds a lake 35 kilometers long and 5 kilometers wide, is a bargain in American higher education. In three weeks a student can earn four credits of upper-division coursework, get original research experience, and, most importantly—especially in an educational milieu increasingly characterized by electronic content and electronic course management—get his or her hands on some live wild plants and animals in an appropriate ecological context. This encounter with nature is typically the first for our high-performer premed students on academic scholarships, who regularly attend CPBS after their junior year. The life-long impact of such experience includes lost naïveté with respect to living systems, appreciation of the relationship between environment and health, and, for some, a career choice leading to professional science

Inhibition of In vitro Macrophage Digestion Capacity by Infection with \u3ci\u3eLeishmania donovani\u3c/i\u3e (Protozoa: Kinetoplastida)

Promastigotes of Leishmania donovani transformed into amastigotes and survived in cultured macrophages. Promastigotes of Leptomonas costoris, a kinetoplastid parasite of water striders, transformed into amastigotes but did not survive in cultured macrophages. A significant difference in size between the two species of parasitic protozoa allowed development of a bioassay in which the in vitro digestion rate of L. costoris was taken as a measure of macrophage digestive capacity following preinfection with L. donovani. In a 12- to 24-hr period, macrophage cultures infected with the 2S strain of L. donovani retained 50% more L. costoris than did control macrophages infected with L. costoris alone. The 2S strain has been in culture since 1967 and has retained its infectivity for hamsters, although its virulence is attenuated. In similar experiments with promastigotes of the Khartoum strain of L. donovani, a strain that evidently has lost its infectivity for hamsters, no such suppression of macrophage ability to digest L. costoris was observed. The results suggest that infective strains of Leishmania donovani suppress macrophage function beyond the time at which initial lysosomal fusion with the parasitophorous vacuole occurs

Physid Snails as Sentinels of Freshwater Nematomorphs

Freshwater nematomorphs, or gordiids, are parasitic as larvae, but free-living in aquatic environments as adults. Studies based on the collection of adults have reported gordiids to be widespread, but discontinuous in distribution. However, a relatively short adult life span and unknown life history make the detection of adults difficult. An alternative approach to investigate gordiid distribution is to use cysts. Of all paratenic hosts, snails were chosen because they lacked internal defense reactions to the cysts and become easily infected. Here, it is reported that the occurrence of gordiids on the basis of the cyst stage is much more common than previously reported, thus altering the perception of how common these worms are. Using this modified survey procedure, gordiid cysts were found at 70% of sites examined, in an area where extensive sampling over 3 yr yielded adults only at a single site. Of 1,000 snails dissected, 395 were infected with gordiids (intensity range: 1-465). Furthermore, different types of human-modified landscapes did not affect gordiid distribution, suggesting that as urban and suburban areas sprawl, human encounters or pseudoparasitism with nematomorphs may increase. The results of this study indicate that use of organismal-specific sampling techniques can be critical in studies of parasite distribution and biodiversity

Physid Snails as Sentinels of Freshwater Nematomorphs

Freshwater nematomorphs, or gordiids, are parasitic as larvae, but free-living in aquatic environments as adults. Studies based on the collection of adults have reported gordiids to be widespread, but discontinuous in distribution. However, a relatively short adult life span and unknown life history make the detection of adults difficult. An alternative approach to investigate gordiid distribution is to use cysts. Of all paratenic hosts, snails were chosen because they lacked internal defense reactions to the cysts and become easily infected. Here, it is reported that the occurrence of gordiids on the basis of the cyst stage is much more common than previously reported, thus altering the perception of how common these worms are. Using this modified survey procedure, gordiid cysts were found at 70% of sites examined, in an area where extensive sampling over 3 yr yielded adults only at a single site. Of 1,000 snails dissected, 395 were infected with gordiids (intensity range: 1-465). Furthermore, different types of human-modified landscapes did not affect gordiid distribution, suggesting that as urban and suburban areas sprawl, human encounters or pseudoparasitism with nematomorphs may increase. The results of this study indicate that use of organismal-specific sampling techniques can be critical in studies of parasite distribution and biodiversity

Redescription of the Frog Bladder Fluke \u3ci\u3eGorgoderina attenuata\u3c/i\u3e from the Northern Leopard Frog, \u3ci\u3eRana pipiens\u3c/i\u3e

Morphological characters used to differentiate North American bladder flukes, Gorgoderina spp., are problematic and different authors use different morphological characteristics for distinguishing species. More importantly, no type specimens exist for four of the 12 North American species infecting anuran and caudatan hosts. A redescription of Gorgoderina attenuata (Stafford, 1902) Stafford, 1905 is based on new collections from 6 species of anurans from Arkansas, Nebraska, New York, and Wisconsin. Morphological comparisons between gravid G. attenuata recovered from bullfrogs and northern leopard frogs indicated statistically significant differences in 11 of 28 morphological characters examined. However, there was overlap among all of these characters, and it is unclear whether these morphological types represent host-induced morphological changes in worm morphology or cryptic species. Based on our findings, we suggest that morphological and molecular data from G. attenuata-like worms recovered from the other 23 definitive hosts reported for G. attenuata need to be collected to resolve this issue