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Biological Sciences Faculty Publications

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Articles 1531 - 1560 of 1571

Full-Text Articles in Life Sciences

Structure And Surface Exposure Of Protein-Iis Of Neisseria-Gonorrhoeae Js3, Ralph C. Judd May 1985

Structure And Surface Exposure Of Protein-Iis Of Neisseria-Gonorrhoeae Js3, Ralph C. Judd

Biological Sciences Faculty Publications

Colonies of Neisseria gonorrhoeae JS3, each bearing a predominate protein II (PII) type, were derived from a progenitor transparent colony. Five distinct PIIs were identified and isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The PII bands were excised from gels of unlabeled whole cells and from gels containing lysates of surface-radioiodinated bacteria. These were subjected to alpha-chymotrypsin digestion and two-dimensional peptide mapping, which allowed for a comparison of both the primary structures of the PIIs and the identification of surface-exposed regions of the molecules. The results demonstrated that PIIs are unrelated to either Protein I or Protein III in structure …


Community Ecology, Robert K. Rose, Elmer C. Birney Jan 1985

Community Ecology, Robert K. Rose, Elmer C. Birney

Biological Sciences Faculty Publications

COMMUNITIES with Microtus tend to be structurally simple, usually grasslands or tundra, and to have no more than two species of Microtus and rarely more than six species of small mammals. Microtus often dominates both numerically and in total small mammal biomass, especially at higher latitudes. The small mammal community is most influenced by Microtus through its fluctuations in density, and thus also in biomass, by its relatively high level of diurnal activity, and by its year-round activity. Other species of small mammals may be adversely affected because Microtus usually is larger and behaviorally dominant and also because the mere …


Seasonal-Changes In The Habitat Distribution Of Transient Insectivorous Birds In Southeastern Arizona: Competition Mediated, Richard L. Hutto Jan 1985

Seasonal-Changes In The Habitat Distribution Of Transient Insectivorous Birds In Southeastern Arizona: Competition Mediated, Richard L. Hutto

Biological Sciences Faculty Publications

The distribution and abundance of 26 migratory insectivorous bird species were recorded over an elevational habitat gradient in the Chiricahua Mountains, Arizona for the spring and fall migratory seasons. Most of the species used this area only during migratory passage, and 54% exhibited significant shifts in the habitats occupied from spring to fall. The majority (69%) of species also exhibited significant changes in density within habitats between seasons. Using pairwise correlations of bird densities from 7 habitat types and 2 seasons, I identified 5 groups that contained species whose seasonal distributional patterns were similar to one another but independent and …


Chemical Leaf Repellency To An Attine Ant: Seasonal Distribution Among Potential Host Plant Species, Jerome J. Howard Aug 1984

Chemical Leaf Repellency To An Attine Ant: Seasonal Distribution Among Potential Host Plant Species, Jerome J. Howard

Biological Sciences Faculty Publications

The chemical repellency of leaves to the leaf-cutting, fungus-growing ant Atta cephalotes was surveyed for 42 plant species randomly selected from the dry forest of Santa Rosa National Park, Guanacaste, Costa Rica. The sample represents about one-sixth of the potential host plant species available to the ants in the secondary, semideciduous forest at Santa Rosa. Repellencies of leaf extracts were measured by bioassay. A laboratory colony of A. cephalotes collected from Santa Rosa was used. Three-quarters of the species exhibited significantly repellent nonpolar (lipid-soluble) extractables (e.g., terpenoids, steroids, and waxes), and half of the species exhibited repellent polar extractables (e.g., …


Crystallization Of The Gene 45 Protein From The Dna Replication Fork Of Bacteriophage T4, C. Thaller, B. Alberts, E. Goldsmith, S. Sprang, R. Fletterick Feb 1984

Crystallization Of The Gene 45 Protein From The Dna Replication Fork Of Bacteriophage T4, C. Thaller, B. Alberts, E. Goldsmith, S. Sprang, R. Fletterick

Biological Sciences Faculty Publications

The gene 45 protein from bacteriophage T4 has been purified and is crystallized. This protein is part of the T4 DNA replication complex. The crystallized protein is active in complementation assays. X-ray diffraction analysis is in progress; data are measured for the native and several heavy atom derivatives. The crystals diffract to about 3.5-Å resolution.


Factors Affecting Nest Site Location In Gila Woodpeckers, Jerome J. Korol, Richard L. Hutto Feb 1984

Factors Affecting Nest Site Location In Gila Woodpeckers, Jerome J. Korol, Richard L. Hutto

Biological Sciences Faculty Publications

We investigated the locations of Gila Woodpecker (Melanerpes uropygialis) nest sites in Organ Pipe Cactus National Monument, Arizona. A significantly greater proportion of saguaro cacti in arroyos had woodpecker holes than did those on hillsides, ridgetops or desert flats. Saguaros used for nest-hole excavation were taller and more likely to have branches than randomly chosen saguaros. Both active and inactive nest holes were nonrandomly oriented, with the mean vectors of orientation being in northwesterly directions. Variation in nest-hole orientation probably is not due to seasonal differences in excavations because the orientation of spring active (late March) nest holes was not …


Superior Developmental Stability Of Heterozygotes At Enzyme Loci In Salmonid Fishes, Robb F. Leary, Fred W. Allendorf, Kathy L. Knudsen Jan 1984

Superior Developmental Stability Of Heterozygotes At Enzyme Loci In Salmonid Fishes, Robb F. Leary, Fred W. Allendorf, Kathy L. Knudsen

Biological Sciences Faculty Publications

No abstract provided.


The Pan American Shorebird Program: A Progress Report, J. P. Myers, Gonzalo Castro, Brian Harrington, Marshall Howe, John L. Maron, Enrique Ortiz, Michel Sallaberry A., C. T. Schick, Elier Tablio Jan 1984

The Pan American Shorebird Program: A Progress Report, J. P. Myers, Gonzalo Castro, Brian Harrington, Marshall Howe, John L. Maron, Enrique Ortiz, Michel Sallaberry A., C. T. Schick, Elier Tablio

Biological Sciences Faculty Publications

No abstract provided.


Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose Jan 1984

Breeding Birds In Cedar Stands In The Great Dismal Swamp, Karen A. Terwilliger, Robert K. Rose

Biological Sciences Faculty Publications

The Great Dismal Swamp located in the coastal plain on the Virginia- North Carolina border, has long been recognized as a vegetationally distinctive region with many unusual geological and biological features. Formerly at least twice the currently estimated size of 85,000 hectares (Carter 1979), the Great Dismal Swamp is still shrinking because of a dropping water table caused by more than 200 years of logging, ditching, and other human activities. In 1973, the Union Camp Corporation donated a 19,871-hectare tract located near Suffolk, Virginia. to The Nature Conservancy, which transferred the land to the U.S. Fish and Wildlife Service. This …


An Evaluation Of Small Rodents In Four Dismal Swamp Plant Communities, F. Elizabeth Breidling, Frank P. Day Jr., Robert K. Rose Apr 1983

An Evaluation Of Small Rodents In Four Dismal Swamp Plant Communities, F. Elizabeth Breidling, Frank P. Day Jr., Robert K. Rose

Biological Sciences Faculty Publications

Diversity and density of small rodents in the Dismal Swamp are believed to be low. Reasons for this may be excessive predation, heavy interspecific pressure from large rodents, lack of suitable habitat, low food availability or flooding.

Rodent populations were evaluated using live-traps and pitfall traps in four different Dismal Swamp plant communities. Habitat was compared on the basis of phytomass studies previously reported. Flood levels were recorded during live-trapping sessions. Mast from trees was collected in modified mast collectors, and fed to Peromyscus leucopus in the laboratory.

Only two small rodent species were captured: Ochrotomys nuttalli and Peromyscus leucopus …


Rationale And Suggestions For A Hemispheric Color-Marking Scheme For Shorebirds: A Way To Avoid Chaos, J. P. Myers, John L. Maron, Enrique Ortiz, Gonzalo Castro, Marshall Howe, R.I.G. Morrison, Brian A. Harrington Jan 1983

Rationale And Suggestions For A Hemispheric Color-Marking Scheme For Shorebirds: A Way To Avoid Chaos, J. P. Myers, John L. Maron, Enrique Ortiz, Gonzalo Castro, Marshall Howe, R.I.G. Morrison, Brian A. Harrington

Biological Sciences Faculty Publications

No abstract provided.


Amount And Distribution Of Isozyme Variation In Ponderosa Pine From Eastern Montana, John Herbert Woods, G. M. Blake, Fred W. Allendorf Jan 1983

Amount And Distribution Of Isozyme Variation In Ponderosa Pine From Eastern Montana, John Herbert Woods, G. M. Blake, Fred W. Allendorf

Biological Sciences Faculty Publications

Pinus ponderosa seeds from 50 trees in each of six small isolated stands located within a nine kilometer radius of Colstrip, Montana, were examined at 23 isozyme loci. Megagametophyte and embryo tissue from each seed were screened separately. Measures of genetic diversity showed no significant differences between male and female components within or between stands. The average proportion of heterozygous loci per embryo (He) was not significantly different between stands. For all stands combined, He was 0.012. Genotype proportions did not deviate from expected Hardy-Weinberg proportions.

Nearly 99 % of the genetic diversity resided within individual stands, …


Linkage Disequilibrium Generated By Selection Against Null Alleles At Duplicate Loci, Fred W. Allendorf Jan 1983

Linkage Disequilibrium Generated By Selection Against Null Alleles At Duplicate Loci, Fred W. Allendorf

Biological Sciences Faculty Publications

No abstract provided.


Phytoplankton Studies Within The Virginia Barrier Islands. Iii. Phytoplankton Composition In A Saline Pond On Smith Island, Harold G. Marshall Jan 1983

Phytoplankton Studies Within The Virginia Barrier Islands. Iii. Phytoplankton Composition In A Saline Pond On Smith Island, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton that characterized the Smith Island pond was diverse, with several species of diatoms, dinoflagellates and blue-green algae dominant throughout the year. A total of 146 spp. were noted, predominantly composed of ultra and nanoplankters, that includes representatives from coastal waters. The island ponds are considered eutrophic habitats whose composition is influenced by overwash conditions and in turn introduce populations to surrounding pools and water channels.


Shell-Dropping Behavior Of Western Gulls (Larus Occidentalis), John L. Maron Jul 1982

Shell-Dropping Behavior Of Western Gulls (Larus Occidentalis), John L. Maron

Biological Sciences Faculty Publications

Westem Gulls (Larus occidentalis) at Bodega Bay, California drop shelled prey items to break them. I presented Washington clams (Saxidomus nuttalli) of known weight to free-flying gulls to investigate factors affecting shell-dropping behavior. All adult gulls dropped clams, whereas only 55% of immature gulls did so. The other 45% of immature gulls that were given clams pecked at them on the ground instead. Gulls dropped clams on both hard and soft substrates. Flight distance and kleptoparasitism seemed important in influencing drop location. Adult Western Gulls dropped heavy clams from lower heights than they dropped light clams. …


Structure Of Maltoheptaose By Difference Fourier Methods And A Model For Glycogen, E. Goldsmith, S. Sprang, R. Fletterick Apr 1982

Structure Of Maltoheptaose By Difference Fourier Methods And A Model For Glycogen, E. Goldsmith, S. Sprang, R. Fletterick

Biological Sciences Faculty Publications

The structure of the glucose heptamer, maltoheptaose, has been determined by difference Fourier analysis at 0.25 nm resolution through its binding to phosphorylase a. It is a left-handed helical structure, with 6.5 glucose residues per turn and a rise per residue of 2.4 Å. The molecule shows short-range order when no protein is present to stabilize its conformation in solution. With one exception, the individual torsion angles between sugar residues vary over a narrow range and preserve a good O(2)O(3′) hydrogen bond. The length of an individual chain for glycogen can be extrapolated from the maltoheptaose data …


Electrophoretic Variation In Large Mammals. Iii. The Ringed Seal, Pusa-Hispida, The Harp Seal, Pagophilus-Groenlandicus, And The Hooded Seal, Cystophora-Cristata, V. Simonsen, Fred W. Allendorf, W. F. Eanes, F. O. Kapel Jan 1982

Electrophoretic Variation In Large Mammals. Iii. The Ringed Seal, Pusa-Hispida, The Harp Seal, Pagophilus-Groenlandicus, And The Hooded Seal, Cystophora-Cristata, V. Simonsen, Fred W. Allendorf, W. F. Eanes, F. O. Kapel

Biological Sciences Faculty Publications

No abstract provided.


Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam Jan 1982

Electron Microscopic Demonstration Of Neural Connections Using Horseradish Peroxidase: A Comparison Of The Tetramethylbenzidine Procedure With Seven Other Histochemical Methods, Keith A. Carson, M-Marsel Mesulam

Biological Sciences Faculty Publications

Eight methods for the electron microscopic demonstration of horseradish peroxidase (HRP) labeling have been compared in adjacent series of vibratome sections of mouse lumbar spinal cord. The tracer, a HRP-wheat germ agglutinin (WGA) conjugate, was injected into the gastrocnemius muscle complex. Following retrograde axonal transport to the lumbar motor neurons and transganglionic anterograde transport of the tracer to the dorsal horn, the HRP activity was demonstrated in eight series of adjacent sections of lumbar spinal cord using eight methods. These included procedures using tetramethylbenzidine (TMB), benzidine dihydrochloride (BDHC), o-tolidine, paraphenylenediamine-pyrocatechol (PPD-PC), and 4 methods using 3,3'-diaminobenzidine (DAB). All eight methods …


Small Mammals In Openings In Virginia's Dismal Swamp, Robert K. Rose Dec 1981

Small Mammals In Openings In Virginia's Dismal Swamp, Robert K. Rose

Biological Sciences Faculty Publications

In a study of small mammals of openings in the Dismal Swamp of Virginia, seven species were obtained using pitfall traps. Samples included several species rarely caught in the Swamp - seven specimens of the Dismal Swamp subspecies of the southern bog lemming, Synaptomys cooperi helaletes, the first collected in this century; two least shrews, Cryptotis parva; and 15 southeastern shrews, Sorex longirostris fisheri . Results are compared to previous studies, conducted primarily in forested habitats, in which the white-footed mouse, Peromyscus leucopus, and the golden mouse, Ochrotomys nuttalli, were numerically dominant.


Seasonal Variation In The Foraging Behavior Of Some Migratory Western Wood Warblers, Richard L. Hutto Oct 1981

Seasonal Variation In The Foraging Behavior Of Some Migratory Western Wood Warblers, Richard L. Hutto

Biological Sciences Faculty Publications

I observed the foraging behavior of four warbler species (Dendroica petechia, Oporornis tolmiei, Geothlypis trichas, and Wilsonia pusilla) in the summer in Wyoming and in the winter in Nayarit, Mexico. Of six variables (absolute foraging height, relative foraging height, vegetation density, horizontal foraging position, feeding method, and foraging substrate) believed to be potentially important in distinguishing the warbler species ecologically, the two foragingheight variables provided the greatest separation of the four species in both summer and winter. An analysis of the behavioral similarity of each species from summer to winter revealed that feeding method was the least …


Larval Specialization And Phenotypic Variation In Arctopsyche-Grandis (Trichoptera, Hydropsychidae), F. Richard Hauer, Jack Arthur Stanford Jan 1981

Larval Specialization And Phenotypic Variation In Arctopsyche-Grandis (Trichoptera, Hydropsychidae), F. Richard Hauer, Jack Arthur Stanford

Biological Sciences Faculty Publications

Life history, trophic dynamics, abundance, and microdistribution of Arctopsyche grandis (Banks) were investigated in the Flathead River Basin, Montana. Two morphologically and ecological distinct larvae (Type I, with a head stripe and Type II, without a head stripe) were found throughout the drainage except in lower order streams. Type II larvae grew more rapidly and attained a larger size in final instar than Type I larvae. In areas where A. grandis biomass was greatest, Type I larvae were >10 times as abundant as Type II larvae. Type II larvae selected microhabitats characterized by larger interstitial spaces; Type I larvae were …


Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose Jan 1981

Attributes Of Dispersing Meadow Voles In Open-Grid Populations, Raymond D. Dueser, Marcia L. Wilson, Robert K. Rose

Biological Sciences Faculty Publications

Dispersal was investigated in two open-grid populations of meadow voles, Microtus pennsylvanicus (Ord, 1815) an central Virginia (U.S.A.) from November 1974 to April 1978. "Dispersal" was defined as immigration onto open, occupied population grids. Dispersers were distinguished from residents by weight at first capture. Individuals first captured at weights <30 g were classified as residents; those first captured at >30 g were classified as dispersers. Three independent lines of evidence support the validity of the 30-g criterion for recognizing dispersers in these vole populations. With frequent trapping and high trappability, particularly of young animals, this open-grid method of study offers two advantages in the study of dispersal. First, dispersers identified …


Subunit Interactions And The Allosteric Response In Phosphorylase, S. Sprang, R. J. Fletterick Jan 1980

Subunit Interactions And The Allosteric Response In Phosphorylase, S. Sprang, R. J. Fletterick

Biological Sciences Faculty Publications

The contribution of intersubunit interactions to allosterically induced conformational changes in phosphorylase are considered. Phosphorylase a, Pa (phosphorylated at Ser-14), is significantly in the active (R) conformation, while phosphorylase b, Pb (nonphosphorylated), is predominantly in the inactive (T) conformation. The structure of glucose-inhibited (T) Pa has been determined at 2.5-A resolution and atomic coordinates have been measured. These data have been used to calculate the solvent accessible surface area at the subunit interface and map noncovalent interactions between protomers. The subunit contact involves only 6% of the Pa monomer surface, but withdraws an area of 4,600 A2 from solvent. The …


Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall Jan 1980

Phytoplankton Studies Within The Virginia Barrier Islands I. Seasonal Study Of Phytoplankton In Goose Lake, Parramore Island, Harold G. Marshall

Biological Sciences Faculty Publications

The phytoplankton of Goose Lake, an oligohaline lake on Parramore Island, was studied for one year. The populations consisted primarily of ultraplankton and nanoplankton-sized forms with diatoms and chlorophyceans dominant most of the year. A general pattern of seasonally higher cell concentrations in early summer and fall was noted, with an unidentified ultraplankton-sized component prominent throughout the collection period. A list of 154 species is given.


The Structure Of Glycogen Phosphorylase A At 2.5 Å Resolution, Stephen Sprang, Robert J. Fletterick Jul 1979

The Structure Of Glycogen Phosphorylase A At 2.5 Å Resolution, Stephen Sprang, Robert J. Fletterick

Biological Sciences Faculty Publications

The structure of the glucose-inhibited form of glycogen phosphorylase a has been determined at a resolution of 2.5 Å. With the aid of the primary sequence derived by Titani et al. (1977) for this enzyme, we have constructed an atomic model of the 97,400 molecular weight monomer. A substantial improvement in the electron density map over that reported previously (Fletterick et al., 1976b) was achieved by extension of the data set to 2.5 Å and the inclusion of three additional "heavy-atom" derivatives in the phasing procedure. Main-chain and side-chain electron density are clearly resolved in the map, allowing an unambiguous …


Additional Comments On Reproductive Strategies And Population Fluctuations In Microtine Rodents, Michael S. Gaines, William M. Schaffer, Robert K. Rose Jan 1979

Additional Comments On Reproductive Strategies And Population Fluctuations In Microtine Rodents, Michael S. Gaines, William M. Schaffer, Robert K. Rose

Biological Sciences Faculty Publications

Recently, Schaffer and Tamarin (1973) proposed a model relating changes in reproductive effort (RE) to fluctuating densities in microtine rodents (lemmings and voles). They assumed (and presented data supporting this assumption) that the major effect of increased crowding would be a reduction in survival among prereproductives, thereby lowering the effective fecundity (Schaffer and Rosenzweig 1977) of their parents. As a consequence, Schaffer and Tamarin argued that the optimal reproductive expenditure, E(N), should decline with increasing population size, N. They also deduced the shape of the zero-growth isocline, N*(E), for differing levels of RE and plotted both E(N) and N*(E) on …


The Reproductive Cycle Of Microtus Ochrogaster In Eastern Kansas, Robert K. Rose, Michael S. Gaines Jan 1978

The Reproductive Cycle Of Microtus Ochrogaster In Eastern Kansas, Robert K. Rose, Michael S. Gaines

Biological Sciences Faculty Publications

About 800 Microtus ochrogaster were live—trapped at biweekly intervals from May 1971 through March 1973 in 3 grassland study areas in eastern Kansas, USA. Details of reproduction were determined by autopsy. Population density increased through the first winter, reached a peak in April 1972, then declined sharply during that summer and beyond. Body length, but not body mass, tended to be positively related to density. Both sexes matured at about the same weight; development was somewhat prolonged during the winter months, especially in the winter preceding the population peak. Pregnancy rates were high, approaching maximal iteroparity, throughout the study, with …


Isoenzyme Loci In Brown Trout (Salmo Trutta L.) - Detection And Interpretation From Population Data, Fred W. Allendorf, N. Mitchell, N. Ryman, G. Stahl Jan 1977

Isoenzyme Loci In Brown Trout (Salmo Trutta L.) - Detection And Interpretation From Population Data, Fred W. Allendorf, N. Mitchell, N. Ryman, G. Stahl

Biological Sciences Faculty Publications

Previously reported results on natural populations of brown trout (Salmo trutta L.) urged further studies using additional electrophoretically detectable loci. Samples of brain, eye, heart, kidney, liver, and muscle from approximately 50 specimens from each of two populations and a large number of muscle samples from several additional populations were examined. Electrophoretic and staining methods for the 37 enzymes studied are given in detail. Of a total of 69 loci detected, 54 loci were considered usable in population genetics screenings. The expression of the loci coding for these enzymes is described and interpreted. The results presented will serve as …


On The Sedimentation Behavior And Molecular Weight Of 16s Ribosomal Rna From Escherichia Coli, Walter E. Hill, Kenneth R. Bakke, Donald P. Blair Jan 1977

On The Sedimentation Behavior And Molecular Weight Of 16s Ribosomal Rna From Escherichia Coli, Walter E. Hill, Kenneth R. Bakke, Donald P. Blair

Biological Sciences Faculty Publications

No abstract provided.


Live Trap Preference Among Grassland Mammals, Robert K. Rose, Norman A. Slade, James H. Honacki Jan 1977

Live Trap Preference Among Grassland Mammals, Robert K. Rose, Norman A. Slade, James H. Honacki

Biological Sciences Faculty Publications

In two independent studies, small mammals of grassland communities in eastern Kansas, when given a choice, preferred Fitch to Sherman live traps. Except for the harvest mice in the demographic study, the type of preferred trap and magnitude of selection was remarkably comparable, with microtines showing slight, and cricetines strong, preferences overall. The merits of each type of trap are compared, and related to season, weather, prior experience, and trap-associated mortality.