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Articles 151 - 180 of 337

Full-Text Articles in Biology

Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey L. Brelsfoard, Gary Fritz, Roberto Rodriguez May 2006

Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey L. Brelsfoard, Gary Fritz, Roberto Rodriguez

Faculty Research & Creative Activity

Anopheles fluminensis Root is a member of the Arribalzagia Series in the subgenus Anopheles. We report the first record of this species in the department of Cochabamba, Bolivia. This species was sampled from two locations in the foothills of the eastern Andes Mountains within the Chapare Valley. Larvae were collected in fast-flowing, shaded streams at the edges of rocky pools. We provide the first sequence data for the rDNA of An. fluminensis, a partial sequence of the 5.8S and the internal transcribed spacer 2 (ITS2). The ITS2 of An. fluminensis, sequenced from two individuals at one site, was at least …

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Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey Brelsfoard, Gary Fritz, Roberto Rodriguez May 2006

Sequence Analysis Of The Rdna Internal Transcribed Spacer 2 And Polymerase Chain Reaction Identification Of Anopheles Fluminensis (Diptera: Culicidae: Anopheles) In Bolivia, Corey Brelsfoard, Gary Fritz, Roberto Rodriguez

Faculty Research & Creative Activity

Anopheles fluminensis Root is a member of the Arribalzagia Series in the subgenus Anopheles. We report the first record of this species in the department of Cochabamba, Bolivia. This species was sampled from two locations in the foothills of the eastern Andes Mountains within the Chapare Valley. Larvae were collected in fast-flowing, shaded streams at the edges of rocky pools. We provide the first sequence data for the rDNA of An. fluminensis, a partial sequence of the 5.8S and the internal transcribed spacer 2 (ITS2). The ITS2 of An. fluminensis, sequenced from two individuals at one site, was at least …

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The Clapper Rail As An Indicator Species Of Estuarine Marsh Health, James N. Novak, Karen F. Gaines, James C. Cumbee Jr., Gary L. Mills, Alejandro Rodriguez-Navarro, Christopher S. Romanek Jan 2006

The Clapper Rail As An Indicator Species Of Estuarine Marsh Health, James N. Novak, Karen F. Gaines, James C. Cumbee Jr., Gary L. Mills, Alejandro Rodriguez-Navarro, Christopher S. Romanek

Faculty Research & Creative Activity

Clapper Rails (Rallus longirostris) can potentially serve as an indicator species of estuarinemarsh health because of their strong site fi delity and predictable diet consisting predominantly of benthic organisms. These feeding habits increase the likelihood of individuals accumulating signifi - cant amounts of contaminants associated with coastal sediments. Moreover, since Clapper Rails are threatened in most of their western range, additional study of the effects of potential toxins on these birds is essential to conservation programs for this species. Here we present techniques (DNA strand breakage, eggshell structure, and human-consumption risk) that can be used to quantify detrimental effects to …

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Element Levels In Snakes In South Carolina: Differences Between A Control Site And Exposed Site On The Savannah River Site, J. Burger, S. Murray, K. F. Gaines, James M. Novak, T. Punshon, C. Dixon, M. Gochfeld Jan 2006

Element Levels In Snakes In South Carolina: Differences Between A Control Site And Exposed Site On The Savannah River Site, J. Burger, S. Murray, K. F. Gaines, James M. Novak, T. Punshon, C. Dixon, M. Gochfeld

Faculty Research & Creative Activity

Levels of 18 elements, including lead, mercury, selenium, and uranium, were examined in three species of snakes from an exposed and reference site on the Department of Energy’s Savannah River Site in South Carolina. We tested the hypotheses that there were no differences as a function of species, and there were no difference between the exposed and control site for blood and muscle (tail) samples for banded water snake (Nerodia fasciata), brown water snake (N. taxispilota) and cottonmouth (Akistrodon piscivorous). The banded water snakes collected were significantly smaller than the other two species. For blood, there were significant species differences …

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Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara S. Carlsward, William Louis Stern, Benny Bytebier Jan 2006

Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara S. Carlsward, William Louis Stern, Benny Bytebier

Faculty Research & Creative Activity

The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings …

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Survey Of The Illinois Endangered Kankakee Mallow, Iliamna Remote, In Kankakee County, April L. Mcdonnell, Henry R. Owen, Sean C. Jones, Vincent P. Gutowski, John E. Ebinger Jan 2006

Survey Of The Illinois Endangered Kankakee Mallow, Iliamna Remote, In Kankakee County, April L. Mcdonnell, Henry R. Owen, Sean C. Jones, Vincent P. Gutowski, John E. Ebinger

Faculty Research & Creative Activity

Iliamna remota Greene (Malvaceae), endemic only to Langham Island in the Kankakee River, Kankakee County, Illinois, is a state endangered species. During the present study, the size of the population was determined, the habitat structure in and around the individual colonies analyzed, and management recommendation made to potentially increase the size of the population. During the summer of 2005, the I remota population consisted of 1,074 stems in 12 colonies, located along the northwest side of the island. In late June, flowering appeared to be prolific, where means and standard deviations of floral buds and open flowers were 1.6 :t …

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Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Louis Stern, Barbara S. Carlsward Jan 2006

Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Louis Stern, Barbara S. Carlsward

Faculty Research & Creative Activity

Subtribe Oncidiinae comprises a vegetatively heterogeneous assemblage of species that has persistently been incapable of organization. Anatomy was considered to be a possible means to resolve the perplexity of relationships amongst the constituent taxa. The consistent occurrence of a foliar hypodermis, homogeneous mesophyll, conical silica bodies in stegmata, and ubiquitous fibre bundles in leaves provides a matrix for linking the taxa, as do the parenchymatous pith and O-thickened endodermal cell walls in roots. However, the strict consensus of the 40 genera studied was completely unresolved, suggesting that vegetative characters alone are insufficient to assess the relationships amongst these taxa, a …

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Additions To The Flora Of Rhode Island, Gordon Tucker Jan 2006

Additions To The Flora Of Rhode Island, Gordon Tucker

Faculty Research & Creative Activity

The recent checklist of Rhode Island plants (Gould et al. 1998) provides an excellent documentation of the state's vascular flora. Although geographically distant, I have continued to maintain an interest in the flora of my home state since my first publication on the subject (Tucker 1978). Over the past several years, I have made a few collections that are new records for the state flora. Most are non-native species, and are enumerated below by family.

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Sequence Analysis Of Nuclear Rdna Of Anastrepha Suspensa, Ann Fritz Jan 2006

Sequence Analysis Of Nuclear Rdna Of Anastrepha Suspensa, Ann Fritz

Faculty Research & Creative Activity

No abstract provided.

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Survey Of The Illinois Endangered Kankakee Mallow, Iliamna Remota, In Kankakee County, April L. Mcdonnell, Henry R. Owen, Sean C. Jones, Vincent P. Gutowski, John E. Ebinger Jan 2006

Survey Of The Illinois Endangered Kankakee Mallow, Iliamna Remota, In Kankakee County, April L. Mcdonnell, Henry R. Owen, Sean C. Jones, Vincent P. Gutowski, John E. Ebinger

Faculty Research & Creative Activity

Iliamna remota Greene (Malvaceae), endemic only to Langham Island in the Kankakee River, Kankakee County, Illinois, is a state endangered species. During the present study, the size of the population was determined, the habitat structure in and around the individual colonies analyzed, and management recommendation made to potentially increase the size of the population. During the summer of 2005, the I remota population consisted of 1,074 stems in 12 colonies, located along the northwest side of the island. In late June, flowering appeared to be prolific, where means and standard deviations of floral buds and open flowers were 1.6 :t …

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Effect Of In Ovo Exposure To Pcbs And Hg On Clapper Rail Bone Mineral Chemistry From A Contaminated Salt Marsh In Coastal Georgia, Alejandro Rodriquez-Navarro, Christopher S. Romanek, Pedro Alvarez-Lloret, Karen F. Gaines Jan 2006

Effect Of In Ovo Exposure To Pcbs And Hg On Clapper Rail Bone Mineral Chemistry From A Contaminated Salt Marsh In Coastal Georgia, Alejandro Rodriquez-Navarro, Christopher S. Romanek, Pedro Alvarez-Lloret, Karen F. Gaines

Faculty Research & Creative Activity

The effect of Hg and PCBs (Aroclor 1268) on bone characteristics was investigated in a population of Clapper Rails (Rallus longirostris) inhabiting contaminated and unimpacted estuarine marsh systems in coastal Georgia. Exposure to contaminants did not affect the length or weight of leg bones, but it significantly altered the chemical composition of the bone. Specifically, bone in the contaminated site had a higher Ca to P, and lower carbonate and acid phosphate content. These characteristics are typical of more mature bone mineral and indicate that toxicants have accelerated bone maturation. FTIR spectroscopy data revealed a dose dependent change in the …

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Trehalose Uptake Through P2x7 Purinergic Channels Provides Dehydration Protection, Gloria D. Elliott, Jennifer L. Cusick, Xiang-Hong Liu, Michael A. Menze, Trudy Witt, Steven C. Hand, Mehmet Toner Jan 2006

Trehalose Uptake Through P2x7 Purinergic Channels Provides Dehydration Protection, Gloria D. Elliott, Jennifer L. Cusick, Xiang-Hong Liu, Michael A. Menze, Trudy Witt, Steven C. Hand, Mehmet Toner

Faculty Research & Creative Activity

The tetra-anionic form of ATP (ATP4-) is known to induce monovalent and divalent ion fluxes in cells that express purinergic P2X7 receptors (Steinberg et al., 1987; Sung et al., 1985), and with sustained application of ATP it has been shown that dyes as large as 831 daltons can permeate the cell membrane (Steinberg et al, 1987). The current study explores the kinetics of loading α,α-trehalose (342 daltons) into ATP stimulated J774.A1 cells, which are known to express the purinergic P2X7 receptor (Steinberg et al., 1987). Cells that were incubated at 37 ̊C in a 50 mM phosphate buffer (pH 7.0) …

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Flora And Vegetation Of Coneflower Glacial Drift Hill Prairie Natural Area, Moultrie County, Illinois, Gordon C. Tucker, Nicholas L. Owens, John E. Ebinger Jan 2006

Flora And Vegetation Of Coneflower Glacial Drift Hill Prairie Natural Area, Moultrie County, Illinois, Gordon C. Tucker, Nicholas L. Owens, John E. Ebinger

Faculty Research & Creative Activity

The vascular flora of Coneflower Glacial Drift Hill Prairie Natural Area in Moultrie County, east-central Illinois, was studied during the growing seasons of 2002 and 2003. The prairie is located on a steep SW-facing hillside of the Cerro Gordo Glacial Moraine, overlooking the Kaskaskia River Valley and Lake Shelbyville. The flora was documented by general reconnaissance, and the structure of the vegetation was sampled in September 2003 using 0.25 m2 plots placed along two transects. The site supported 164 vascular plant species (including one named hybrid). The native grasses with the highest importance values were Andropogon gerardii (big bluestem) and …

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Additions To The Flora Of Rhode Island, Gordon C. Tucker Jan 2006

Additions To The Flora Of Rhode Island, Gordon C. Tucker

Faculty Research & Creative Activity

The recent checklist of Rhode Island plants (Gould et al. 1998) provides an excellent documentation of the state's vascular flora. Although geographically distant, I have continued to maintain an interest in the flora of my home state since my first publication on the subject (Tucker 1978). Over the past several years, I have made a few collections that are new records for the state flora. Most are non-native species, and are enumerated below by family.

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Sequence Analysis Of Nuclear Rdna Of Anastrepha Suspensa, Ann H. Fritz Jan 2006

Sequence Analysis Of Nuclear Rdna Of Anastrepha Suspensa, Ann H. Fritz

Faculty Research & Creative Activity

No abstract provided.

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Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. C. Jones, W. J. Jordan, Scott J. Meiners, A. N. Miller, A. S. Methven Jan 2006

Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. C. Jones, W. J. Jordan, Scott J. Meiners, A. N. Miller, A. S. Methven

Faculty Research & Creative Activity

Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate …

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Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian Peer, Lyndon Hawkins, Edwin Steinke, Patricia Bollinger, Eric Bollinger Jan 2006

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian Peer, Lyndon Hawkins, Edwin Steinke, Patricia Bollinger, Eric Bollinger

Faculty Research & Creative Activity

The relationship between the Brownheaded Cowbird (Molothrus ater) and its cavitynesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n = 20), but ejected no experimentally added conspecific eggs (n = 66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, …

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Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara Carlsward, William Stern, Benny Bytebier Jan 2006

Comparative Vegetative Anatomy And Systematics Of The Angraecoids (Vandeae, Orchidaceae) With An Emphasis On The Leafless Habit, Barbara Carlsward, William Stern, Benny Bytebier

Faculty Research & Creative Activity

The vegetative anatomy and morphology of 142 species of the angraecoid orchids (Angraecinae + Aerangidinae) and 18 species of Aeridinae were examined using light and scanning electron microscopy. Leafless members of Vandeae were of particular interest because of their unique growth habit. Leafy and leafless members of Angraecinae and Aerangidinae were examined and compared with specimens of Aeridinae. Vandeae were homogeneous in both leaf and root anatomy. A foliar hypodermis and fibre bundles were generally absent. Stegmata with spherical silica bodies were found associated with sclerenchyma and restricted to leaves in almost all specimens examined. Distinct inner tangential wall thickenings …

Go to article

Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Stern, Barbara Carlsward Jan 2006

Comparative Vegetative Anatomy And Systematics Of Oncidiinae (Maxillarieae, Orchidaceae), William Stern, Barbara Carlsward

Faculty Research & Creative Activity

Subtribe Oncidiinae comprises a vegetatively heterogeneous assemblage of species that has persistently been incapable of organization. Anatomy was considered to be a possible means to resolve the perplexity of relationships amongst the constituent taxa. The consistent occurrence of a foliar hypodermis, homogeneous mesophyll, conical silica bodies in stegmata, and ubiquitous fibre bundles in leaves provides a matrix for linking the taxa, as do the parenchymatous pith and O-thickened endodermal cell walls in roots. However, the strict consensus of the 40 genera studied was completely unresolved, suggesting that vegetative characters alone are insufficient to assess the relationships amongst these taxa, a …

Go to article

Flora And Vegetation Of Coneflower Glacial Drift Hill Prairie Natural Area, Moultrie County, Illinois, Gordon Tucker, Nicholas Owens, John Ebinger Jan 2006

Flora And Vegetation Of Coneflower Glacial Drift Hill Prairie Natural Area, Moultrie County, Illinois, Gordon Tucker, Nicholas Owens, John Ebinger

Faculty Research & Creative Activity

The vascular flora of Coneflower Glacial Drift Hill Prairie Natural Area in Moultrie County, east-central Illinois, was studied during the growing seasons of 2002 and 2003. The prairie is located on a steep SW-facing hillside of the Cerro Gordo Glacial Moraine, overlooking the Kaskaskia River Valley and Lake Shelbyville. The flora was documented by general reconnaissance, and the structure of the vegetation was sampled in September 2003 using 0.25 m2 plots placed along two transects. The site supported 164 vascular plant species (including one named hybrid). The native grasses with the highest importance values were Andropogon gerardii (big bluestem) and …

Go to article

Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. Jones, W. Jordan, Scott Meiners, A. Miller, A. Methven Jan 2006

Fungal Spore Dispersal By The Eastern Box Turtle (Terrapene Carolina Carolina), S. Jones, W. Jordan, Scott Meiners, A. Miller, A. Methven

Faculty Research & Creative Activity

Although spores from most macrofungi are wind- or water-dispersed, dispersal may also occur via biotic vectors. The Eastern box turtle (Terrapene carolina carolina) is a facultative mycovore that may play an important role in fungal spore dispersal although, to date, no information exists on fungi occurring in fecal samples of box turtles or on the ecological significance of box turtles as spore dispersal vectors. Consequently, a study of the potential for Eastern box turtles to act as vectors for spore dispersal was initiated by capturing wild turtles and collecting fecal samples. Serial dilutions from fecal samples were made to enumerate …

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Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger Jan 2006

Eastern Bluebirds Eject Brown-Headed Cowbird Eggs, Brian D. Peer, Lyndon R. Hawkins, Edwin P. Steinke, Patricia Blair Bollinger, Eric K. Bollinger

Faculty Research & Creative Activity

The relationship between the Brownheaded Cowbird (Molothrus ater) and its cavitynesting hosts has received little attention because of the assumption that cowbirds rarely parasitize these hosts. We tested the Eastern Bluebird (Sialia sialis), a host that is sometimes heavily parasitized by cowbirds, for egg ejection behavior. Bluebirds ejected 65% of experimentally added cowbird eggs (n = 20), but ejected no experimentally added conspecific eggs (n = 66). This suggests that cowbird parasitism, not conspecific brood parasitism, is the selective pressure responsible for egg ejection in this species. This level of rejection may be conservative because bluebirds nest in dark cavities, …

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Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott J. Meiners Jan 2005

Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott J. Meiners

Faculty Research & Creative Activity

The exotic tree, Acer platanoides, is increasing in forests of northeastern North America, largely within the range of its native congener, Acer saccharum. A combination of field and controlled experiments was used on seeds and seedlings of these congeners to determine species characteristics that may be contributing to these floristic changes. Acer platanoides experienced lower rates of seed predation than A. saccharum in field experiments. Differences in the dispersal and allocation characteristics of the two species were small and not likely to explain the relative success of A. platanoides. Greenhouse- grown seedlings of A. platanoides were much larger than those …

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The Social Environment Affects Mate Guarding Behavior In Japanese Beetles, Popillia Japonica, Yoriko Saeki, Kipp C. Kruse, Paul Switzer Jan 2005

The Social Environment Affects Mate Guarding Behavior In Japanese Beetles, Popillia Japonica, Yoriko Saeki, Kipp C. Kruse, Paul Switzer

Faculty Research & Creative Activity

The effect of the social environment on post-copulatory mate guarding duration in Japanese beetles, (Popillia japonica Newman), was examined in a laboratory experiment. The mate guarding durations of beetles in different sex ratios and densities were observed for 10 hours. Guarding duration was longer when females were larger, suggesting the presence of ‘cryptic’ male mate choice. Densities, but not sex ratio, affected the duration of guarding bouts, with males guarding for longer at higher densities. This result implies that males increase their guarding duration under conditions in which their female may be likely to be encountered by other males. The …

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Vegetation And Flora Of American Beech Woods Nature Preserve, Clark County, Illinois, Bob Edgin, Gordon Tucker, John Ebinger Jan 2005

Vegetation And Flora Of American Beech Woods Nature Preserve, Clark County, Illinois, Bob Edgin, Gordon Tucker, John Ebinger

Faculty Research & Creative Activity

No abstract provided.

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Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott Meiners Jan 2005

Seed And Seedling Ecology Of Acer Saccharum And Acer Platanoides: A Contrast Between Native And Exotic Congeners, Scott Meiners

Faculty Research & Creative Activity

The exotic tree, Acer platanoides, is increasing in forests of northeastern North America, largely within the range of its native congener, Acer saccharum. A combination of field and controlled experiments was used on seeds and seedlings of these congeners to determine species characteristics that may be contributing to these floristic changes. Acer platanoides experienced lower rates of seed predation than A. saccharum in field experiments. Differences in the dispersal and allocation characteristics of the two species were small and not likely to explain the relative success of A. platanoides. Greenhouse- grown seedlings of A. platanoides were much larger than those …

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Habitat And Exposure Modelling For Ecological Risk Assessment: A, T. Edwin Chow, Karen F. Gaines, Michael E. Hodgson, Machelle D. Wilson Jan 2005

Habitat And Exposure Modelling For Ecological Risk Assessment: A, T. Edwin Chow, Karen F. Gaines, Michael E. Hodgson, Machelle D. Wilson

Faculty Research & Creative Activity

Contamination has a dramatic impact on the health of ecosystem and habitat suitability for the inhabited flora and fauna. The Environmental Protection Agency (EPA) mandates an ecological risk assessment (ERA) that evaluates the potential adverse impact of any anthropogenic activities on the ecosystem (US Environmental Protection Agency, 1997. Ecological Risk Assessment Guidance for Superfund: Process for Designing and Conducting Ecological Risk Assessment. EPA/630/R-021011, Washington, DC). This study provides a general framework and specific procedures to predict the contaminant exposure of midsized mammals using a geographical information system (GIS)-based Monte Carlo simulation model. The model was applied to the raccoons (Procyon …

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Temporal Patterns In Fall Migrant Communities In Yucatan, Mexico, Jill Deppe, John Rotenberry Jan 2005

Temporal Patterns In Fall Migrant Communities In Yucatan, Mexico, Jill Deppe, John Rotenberry

Faculty Research & Creative Activity

We quantified temporal turnover in the composition of fall migrant landbird communities along the northern coast of the Yucatan Peninsula using Detrended Correspondence Analysis. The presence of winter residents of many migrant species at the site prevented turnover from being complete. However, early and late season transient communities shared few, if any, species in common. Point-count surveys showed greater compositional change than net surveys that included winter residents. The rate of species turnover was generally slow until the middle of the season, when it reached a maximum, and decreased again toward the end of the season as species composition began …

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Allosteric Models For Multimeric Proteins: Oxygen-Linked Effector Binding In Hemocyanin, Michael A. Menze, Nadja Hellman, Heinz Decker, Manfred K. Grieshaber Jan 2005

Allosteric Models For Multimeric Proteins: Oxygen-Linked Effector Binding In Hemocyanin, Michael A. Menze, Nadja Hellman, Heinz Decker, Manfred K. Grieshaber

Faculty Research & Creative Activity

In many crustaceans, changing concentrations of several low molecular weight compounds modulates hemocyanin oxygen binding, resulting in lower or higher oxygen affinities of the pigment. The nonphysiological effector caffeine and the physiological modulator urate, the latter accumulating in the hemolymph of the lobster Homarus Vulgaris during hypoxia, increase hemocyanin oxygen affinity and decrease cooperativity of oxygen binding. To derive a model that describes the mechanism of allosteric interaction between hemocyanin and oxygen in the presence of urate or caffeine, studies of oxygen, urate, and caffeine binding to hemocyanin were performed. Exposure of lobster hemocyanin to various pH values between 7.25 …

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Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang-Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner Jan 2005

Trehalose Loading Through The Mitochondrial Permeability Transition Pore Enhances Desiccation Tolerance In Rat Liver Mitochondria, Xiang-Hong Liu, Alptekin Aksan, Michael A. Menze, Steven C. Hand, Mehmet Toner

Faculty Research & Creative Activity

Trehalose has extensively been used to improve the desiccation tolerance of mammalian cells. To test whether trehalose improves desiccation tolerance of mammalian mitochondria, we introduced trehalose into the matrix of isolated rat liver mitochondria by reversibly permeabilizing the inner membrane using the mitochondrial permeability transition pore (MPTP). Measurement of the trehalose concentration inside mitochondria using high perfOrmance liquid chromatography showed that the sugar permeated rapidly into the matrix upon opening the MPTP. The concentration of intra matrix trehalose reached 0.29 mmoVmg protein (-190 mM) in 5 min. Mitochondria, with and without trehalose loaded into the matrix, were desiccated in a …

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