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Articles 21811 - 21840 of 24572
Full-Text Articles in Physical Sciences and Mathematics
Limits To Ice Thickness In Iowa During The Late Wisconsinan, Eric C. Brevik
Limits To Ice Thickness In Iowa During The Late Wisconsinan, Eric C. Brevik
Journal of the Iowa Academy of Science: JIAS
Minimum and maximum limits to Des Moines Lobe ice thickness in Iowa during the Late Wisconsinan glaciation are calculated. These limits are based on minimum and maximum ice thickness calculations for the Des Moines Lobe in eastern North Dakota using crustal depression indicated by Lake Agassiz strandlines. Minimum and maximum basal shear stresses for the Des Moines Lobe are calculated by projecting a flow line from the terminus of the Des Moines Lobe back up-ice to the study site in northeastern North Dakota. Ice thickness in Iowa is then calculated with a method that uses the basal shear stress values. …
Cover - Investigating Amphibian Declines: Proceedings Of The 1998 Declining Amphibians Conference
Cover - Investigating Amphibian Declines: Proceedings Of The 1998 Declining Amphibians Conference
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Interactive Effects Of Anthropogenic, Environmental, And Biotic Stressors On Multiple Endpoints In Hyla Chrysoscelis, Carol A. Britson, Stephen T. Threlkeld
Interactive Effects Of Anthropogenic, Environmental, And Biotic Stressors On Multiple Endpoints In Hyla Chrysoscelis, Carol A. Britson, Stephen T. Threlkeld
Journal of the Iowa Academy of Science: JIAS
Multiple stressors have been proposed as causative agents for declining populations and increased incidence of malformations in amphibians although few studies have examined possible interactions among these stressors. We measured interactive effects of UV radiation, three chemicals, and interspecific competition (with Rana 1phenocephala) on multiple endpoints in Hyla chrysoscelis using a center point- and chemical-free control-enhanced 24 factorial design. UV radiation was transmitted or filtered using OP-4 or OP-3 acrylite filters installed above 72, 500-liter mesocosms on 16 May 1997. Methyl mercury, chlorpyrifos, and atrazine were applied at levels of 0, 10, 50, and 100 % of 400 ppb, …
A Relationship Between Trematode Metacercariae And Bullfrog Limb Abnormalities, James L. Christiansen, Heather Feltman
A Relationship Between Trematode Metacercariae And Bullfrog Limb Abnormalities, James L. Christiansen, Heather Feltman
Journal of the Iowa Academy of Science: JIAS
This study is the first report of statistically significant relationships between limb abnormalities and trematode metacercariae in natural populations of frogs. We examined only parasite associations and did not investigate numerous potential pollutants that have been suggested by others to be associated with frog limb abnormalities. Rana catesbeiana of varying ages with a variety of limb abnormalities were found during the flood of 1993. By June 1994, the receding flood waters had left four pools, each with newly metamorphosing bullfrogs. Only one of the pools contained abnormal individuals and histological examination revealed significantly greater prevalence of trematode metacercarial infection in …
History Of Minnesota Frog Abnormalities: Do Recent Findings Represent A New Phenomenon?, David M. Hoppe
History Of Minnesota Frog Abnormalities: Do Recent Findings Represent A New Phenomenon?, David M. Hoppe
Journal of the Iowa Academy of Science: JIAS
Two lines of investigation were used to determine whether recent Minnesota reports of frog abnormalities differ from historical reports: (1) museum collection studies paired with follow-up field surveys, and (2) comparison of recent and earlier field surveys in west-central Minnesota. For the museum study I examined 2433 northern leopard frogs (Rana pipiens) in the Bell Museum of Natural History collections of the University of Minnesota, collected during 1958-63. 0.7% of frogs were found to have abnormalities, consisting of 0.5% predator amputations and 0.2% malformations. Three types of malformation were found: missing hindlimbs, vestigial feet, and fused digits. Conspicuously absent from …
Field Surveys Of Midwestern And Northeastern Fish And Wildlife Service Lands For The Presence Of Abnormal Frogs And Toads, Kathryn A. Converse, James Mattsson, Laura Eaton-Poole
Field Surveys Of Midwestern And Northeastern Fish And Wildlife Service Lands For The Presence Of Abnormal Frogs And Toads, Kathryn A. Converse, James Mattsson, Laura Eaton-Poole
Journal of the Iowa Academy of Science: JIAS
The national distribution of information on the discovery of malformations in Minnesota frogs in 1995 stimulated collection and examination of newly metamorphosed frogs during 1996. By late summer and early fall of 1996, malformed frogs and toads were reported on U.S. Fish and Wildlife Service (USFWS) lands in Vermont (Northeast, Region 5) and Minnesota (Midwest, Region 3). In response to these reports, biologists in USFWS Regions 3 and 5 conducted a survey, during the summer of 1997 to determine the distribution and type of malformations in frogs and toads on selected Federal lands. Region 3 personnel surveyed 38 field stations …
A Winter/Spring Study Of Salamanders In A Disturbed, Fragmented Habitat Surrounded By Farm Land, James C. Ball
A Winter/Spring Study Of Salamanders In A Disturbed, Fragmented Habitat Surrounded By Farm Land, James C. Ball
Journal of the Iowa Academy of Science: JIAS
The continued development of fragmented habitats contributes to the decline of amphibians species, and there needs to be a method for evaluating the potential of these habitats to sustain amphibian populations. The effect of fragmented and disturbed habitats among salamander species is difficult to assess because these caudates are difficult to find and enumerate. One approach for estimating the total population of salamanders is to sample them when they migrate to their winter/spring breeding ponds. One fragmented habitat in Southern Michigan was sampled for breeding salamanders during the winter/spring of 1997. Four species of salamanders were detected at this site; …
Reduction In Road Mortality In A Northern Leopard Frog Population, Madeleine H. Linck
Reduction In Road Mortality In A Northern Leopard Frog Population, Madeleine H. Linck
Journal of the Iowa Academy of Science: JIAS
Since spring of 1994, Hennepin Parks Natural Resources Management staff, assisted by numerous volunteers, has been working to reduce road mortality among migrating Northern Leopard Frogs (Rana pipiens) adjacent to Baker Park Reserve in Maple Plain, Hennepin County, Minnesota. A county road separates the overwintering site from breeding habitat within the park. With steadily increasing traffic over the years, this population of frogs was in serious decline. For the first two years (1994 and 1995) rescue efforts were limited to the spring collection of frogs as they migrated out of the overwintering lake coward the breeding wetlands, although the road …
Index For Volume 107
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Cover - Table Of Contents
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Weed Seedbanks And Seedling Emergence In A Two And Three Crop Narrow Strip Intercropping/Rotation System, Shawn R. Wright, Douglas D. Buhler, Keith A. Kohler, Richard M. Cruse
Weed Seedbanks And Seedling Emergence In A Two And Three Crop Narrow Strip Intercropping/Rotation System, Shawn R. Wright, Douglas D. Buhler, Keith A. Kohler, Richard M. Cruse
Journal of the Iowa Academy of Science: JIAS
Weed populations in agronomic settings are, in part, a reflection of the cropping system utilized. The goal of this project was to gain an understanding of the weed population dynamics in a narrow strip intercropping (NSI) rotation by assessing the weed seedbank, weed emergence, and seedling establishment over the growing season for a corn-soybean (two-crop), and a corn-soybean-oat+berseem clover (three-crop) system. Field research was conducted in 1994 and 1995, near Nashua, IA, and each crop was grown m 4.6 m wide strips. Giant foxtail and total weed seed densities were significantly lower in the three-crop NSI rotation system than in …
Book Review: An Illustrated Guide To Iowa Prairie Plants, Paul Weihe
Book Review: An Illustrated Guide To Iowa Prairie Plants, Paul Weihe
Journal of the Iowa Academy of Science: JIAS
An Illustrated Guide to Iowa Prairie Plants. Paul Christiansen and Mark Müller. 1999. University of Iowa Press, Iowa City, Iowa. IX + 237 pages. ISBN 0-87745-660-7 hdbd., ISBN 0-87745- 661-5 pbk.
Iowans are increasingly aware of the significance of the tallgrass prairie, and efforts to preserve and protect this once-widespread ecosystem are ongoing. An obvious focus of these efforts 1s to conserve the native flora. When Bison and Elk disappeared from the landscape and row-crop agriculture appeared, a few of the native plants remained in old cemeteries, along roadsides, and in a few prairie remnants. Workers are now attempting to …
Announcements Of Upcoming Meetings And Symposia
Announcements Of Upcoming Meetings And Symposia
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Introduction: A Perspective On Midwest Amphibian Declines, Gary S. Casper
Introduction: A Perspective On Midwest Amphibian Declines, Gary S. Casper
Journal of the Iowa Academy of Science: JIAS
On March 21, 1998, approximately 300 scientists and students gathered at the Milwaukee Public Museum for two days of scientific presentations and intense discussion on amphibian declines and malformities. Never before had so many persons come together to address amphibian conservation in the Midwestern United States (Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio, Iowa, and Missouri).
Photo-Enhanced Toxicity In Amphibians: Synergistic Interactions Of Solar Ultraviolet Radiation And Aquatic Contaminants, Edward E. Little, Robin Calfee, Richard Skinker, Angela Zaga-Parkhurst, Mace G. Barron
Photo-Enhanced Toxicity In Amphibians: Synergistic Interactions Of Solar Ultraviolet Radiation And Aquatic Contaminants, Edward E. Little, Robin Calfee, Richard Skinker, Angela Zaga-Parkhurst, Mace G. Barron
Journal of the Iowa Academy of Science: JIAS
Amphibians experience a broad range of multiple environmental stressors that occur in natural systems. However, the impact of combinations of these stressors on amphibians are rarely examined. The effect of two stressors on amphibians, solar ultraviolet radiation (SUV) and environmental contamination, was investigated. To examine the interactive effects of SUV and environmental contaminants, Hyla venicolor and Rana sphenocephala were exposed in the laboratory to a carbamate insecticide and the water soluble fraction of a weathered petroleum in combination with various intensities of simulated solar radiation (SSR). The contaminants were tested at environmentally relevant concentrations. Synergistic interactions between SSR and these …
Landscape Associations Of Frog And Toad Species In Iowa And Wisconsin, U.S.A., Melinda G. Knutson, John R. Sauer, Douglas A. Olsen, Michael J. Mossman, Lisa M. Hemesath, Michael J. Lannoo
Landscape Associations Of Frog And Toad Species In Iowa And Wisconsin, U.S.A., Melinda G. Knutson, John R. Sauer, Douglas A. Olsen, Michael J. Mossman, Lisa M. Hemesath, Michael J. Lannoo
Journal of the Iowa Academy of Science: JIAS
Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), …
Amphibian Use Of Constructed Ponds On Maryland's Eastern Shore, Catherine E. Merovich, James H. Howard
Amphibian Use Of Constructed Ponds On Maryland's Eastern Shore, Catherine E. Merovich, James H. Howard
Journal of the Iowa Academy of Science: JIAS
Amphibian assemblages were sampled at nine constructed ponds (three in each age category: new ponds-age <1 yr, young ponds-age 4-5 yr, old ponds-age >30 yr) on Maryland's eastern shore (May-October 1994, March-August 1995) using a total of 27 drift fence and funnel trap arrays. The importance of habitat and landscape variables including pond age was considered in explaining amphibian use and distribution across ponds. Specifically, amphibian (1) abundance; (2) composition; (3) diversity; (4) richness; and (5) reproductive success were studied. During both years, we captured 1904 individuals comprising ten species. The most frequently collected species (species found in all treatments) were Bufo fowleri, Rana sphenocephala utricularius, and Rana …1>
Amphibians And Reptiles Captured In Drift Fences In Northwest Wisconsin Pine Barrens, James O. Evrard, Steven R. Hoffman
Amphibians And Reptiles Captured In Drift Fences In Northwest Wisconsin Pine Barrens, James O. Evrard, Steven R. Hoffman
Journal of the Iowa Academy of Science: JIAS
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 …
Differences Among The Spatial Distribution Of Sympatric Amphibians, Robert Brodman
Differences Among The Spatial Distribution Of Sympatric Amphibians, Robert Brodman
Journal of the Iowa Academy of Science: JIAS
To assess amphibian declines, the factors that cause natural fluctuations in population size must be considered (Pechmann et al. 1991). Interspecific competition, predation and pond drying are known to influence patterns of distribution and composition of larval amphibian assemblages (Morin 1983, Brodman 1996, Skelly 1996). While a few studies have quantified amphibian patterns across a large number of ponds, most studies on breeding pond distributions have typically focused on pond characteristics associated with pairs of coexisting species (Thompson and Gates 1982, Skelly 1996). Little has been examined about the differences among the spatial distributions of all potentially interacting amphibian populations …
Amphibian And Reptile Surveys In The Kaskaskia River Drainage Of Illinois During 1997 And 1998, Allan K. Wilson
Amphibian And Reptile Surveys In The Kaskaskia River Drainage Of Illinois During 1997 And 1998, Allan K. Wilson
Journal of the Iowa Academy of Science: JIAS
Currently there is little doubt among the scientific community of the decline of amphibians on an international scale (Berger et al. 1998, Kuzmin 1994, Laurance et al. 1996, Lips 1998) and across North America (Delis et al. 1996, Drost and Fellers 1996, Lannoo 1994). In light of these widespread declines it is essential that current populations be inventoried and evaluated so that future population changes can be detected and hopefully correlated with possible causes. Critical baseline information is lost when monitoring is not implemented until after a problem is detected. The effectiveness of long-term studies in detecting amphibian declines (Beebee …
Editorial Board & Iowa Academy Of Science Officers And Directors
Editorial Board & Iowa Academy Of Science Officers And Directors
Journal of the Iowa Academy of Science: JIAS
No abstract provided.
Higher Population And Twin Row Configuration Does Not Benefit Strip Intercropped Corn, M. M. Harbur, R. M. Cruse
Higher Population And Twin Row Configuration Does Not Benefit Strip Intercropped Corn, M. M. Harbur, R. M. Cruse
Journal of the Iowa Academy of Science: JIAS
Increased corn (Zea mays L.) grain yield with strip intercropping, made possible because of increased edge effects, makes this soil-conserving crop production system appealing to farmers. The objective of this study was to determine the population and row configuration needed to optimize the additional yield potential in each outside corn row. Treatments 'included: 74, 99, and 124 thousand plants ha-1 were grown in twin rows and 74 thousand plants ha-1 grown in single rows. Single rows or twin row centers were spaced 0.76 m. The experiment was conducted at four central Iowa sites during 1996 and 1997. Grain …
Defining Anuran Malformations In The Context Of A Developmental Problem, Carol U. Meteyer, Rebecca A. Cole, Kathryn A. Converse, Douglas E. Docherty, Mark Wolcott, Judy C. Helgen, Richard Levey, Laura Eaton-Poole, James G. Burkhart
Defining Anuran Malformations In The Context Of A Developmental Problem, Carol U. Meteyer, Rebecca A. Cole, Kathryn A. Converse, Douglas E. Docherty, Mark Wolcott, Judy C. Helgen, Richard Levey, Laura Eaton-Poole, James G. Burkhart
Journal of the Iowa Academy of Science: JIAS
This paper summarizes terminology and general concepts involved in animal development for the purpose of providing background for the study and understanding of frog malformations. The results of our radiographic investigation of rear limb malformations in Rana pipiens provide evidence that frog malformations are the product of early developmental errors. Although bacteria, parasites and viruses were identified in these metamorphosed frogs, the relevant window to look for the teratogenic affect of these agents is in the early tadpole stage during limb development. As a result, our microbiological findings must be regarded as inconclusive relative to determining their contribution to malformations …
Effects Of Altosid And Abate-4e On Deformities And Survival In Southern Leopard Frogs Under Semi-Natural Conditions, Donald W. Sparling
Effects Of Altosid And Abate-4e On Deformities And Survival In Southern Leopard Frogs Under Semi-Natural Conditions, Donald W. Sparling
Journal of the Iowa Academy of Science: JIAS
Since 1995 when a group of school children in Minnesota found frogs with supernumerary limbs and missing limbs, there has been widespread interest in the amphibian malformation issue. Despite considerable effort to understand this problem, its extent and seriousness as well as direct causes of these malformations remain unclear. Progress on this issue has been hampered by a scarcity of scientifically reliable information on historical rates of abnormalities under undisturbed conditions and by the normal turnaround times of data collection, sample analysis and publication. One of the very few peer-reviewed publications with field-collected data showed that an average of 12% …
Wetland Mitigation And Amphibians: Preliminary Observations At A Southwestern Illinois Bottomland Hardwood Forest Restoration Site, Kenneth S. Mierzwa
Wetland Mitigation And Amphibians: Preliminary Observations At A Southwestern Illinois Bottomland Hardwood Forest Restoration Site, Kenneth S. Mierzwa
Journal of the Iowa Academy of Science: JIAS
Much has been written on amphibian declines attributed to habitat loss or fragmentation. Much less is known about the response of amphibians to restoration of wetland habitat. Amphibians were monitored at a series of southwestern Illinois wetland mitigation sites from 1995-1998. By the end of the study period, all seven species of amphibians previously known from the site had been found within restored wetlands, and an eighth species had apparently colonized the site. Amphibian species associated with open sunlit wetlands were the first to enter the mitigation sites and were the most abundant. As trees mature and mitigation sites become …
The Wheat Book : Principles And Practice, W K. Anderson, J R. Garlinge
The Wheat Book : Principles And Practice, W K. Anderson, J R. Garlinge
Bulletins 4000 -
Contents : Environment / revised by J. Cramb, J. Courtney and P. Tille - The structure and development of the cereal plant / revised by T.L. Setter and G. Carlton - Germination, vegetative and reproductive growth / revised by T.L. Setter and G. Carlton - Crop water use / D. Tennant - Nutrition / revised by M.D.A. Bolland, R.F. Brennan, J.W. Bowden, M.G. Mason, N.K. Edwards, M.M. Riley and S.W. Gartrell - Wheat in farming systems / revised by B. Bowden, P. Blackwell, P. Carmody, M. Ewing, R. Kingwell, R. L ghman, I. McFarlane, P. Michael, P. Nelson, I. Pritchard, …