Digital Commons Network^™

"Introduction" (To Alfred Russel Wallace; An Anthology Of His Shorter Writings), Charles H. Smith

DLPS Faculty Publications

No abstract provided.

Fungal Development And Host Cell Responses To The Rust Fungus Puccinia Substriata Var. Indica In Seedling And Mature Leaves Of Susceptible And Resistant Pearl Millet [Abstract], Josephine Taylor, C. W. Mims

Faculty Publications

No abstract provided.

Culture Medium Ph Is Influenced By Basal Medium, Carbohydrate Source, Gelling Agent, Activated Charcoal, And Medium Storage Method, Henry R. Owen, Donna Wengerd, A. Raymond Miller

Faculty Research & Creative Activity

When four carbohydrates were tested against six commonly cited inorganic basal media, post-autoclave pH was highest for carbohydrate-free and sucrose- containing media, and progressively lower for maltose-, P lucose-, and fructose-containing media, respectively, post-autoclave pH for these media without carbohydrates was related to medium buffering capacity. Addition of gelling agents (10 of 11 tested) increased the post¬autoclave pH of MS medium containing sucrose. Neutralized and acid-washed activated charcoal also increased the post-autoclave pH of liquid and agar- solidified MS medium, and the pH changed further during 8 weeks of storage. Changes in medium pH caused by gelling agents, but not …

Scirpus Polyphyllus (Cyperaceae) In New Hampshire, Gordon C. Tucker

Faculty Research & Creative Activity

No abstract provided.

Catch-Effort Estimation Of White-Tailed Deer Population Size, James M. Novak, Kim T. Scribner, William D. Dupont, Michael H. Smith

Faculty Research & Creative Activity

Estimation of population size is important for most research in population biology and in the management of game species. Using a stochastic, catch-effort, competing risks model (Dupont 1983), we estimated the population size of the Savannah River Site white-tailed deer (Odocotleus virginianus) herd for 1965-86. Population size varied markedly in response to changes in both hunting method and pressure. Still hunters preferentially harvested older animals compared to dog hunters. Deer were 2.37 times more susceptible to harvest from dog hunting than from still hunting. Hunter-induced mortality was estimated as 1.73 and 4.10 times as large as nonhunting mortality for still …

Frequency Distribution Of Conception Dates In A White-Tailed Deer Herd, James M. Novak, Olin E. Rhodes, Michael H. Smith, Paul E. Johns

Faculty Research & Creative Activity

Conception dates of white-tailed deer, Odocoi/eus virginia1111s (Zinunennann, 1780) were estimated for the breeding periods of 1974 - 76 and 1984 using fall and winter- spring fetal data. Conception dates estimated from data collected in the fall were biased. This bias resulted in an earlier mean conception date than that based on information which included data from later breeding females. Mean breeding dates differed significantly between female age classes due to delayed conception in fawns which also resulted in a skewed frequency distribution of conception dates. The frequency distribution of conception dates was leptokurtotic, suggesting that the distribution is constrnincd …

Review Of Pacific Marlins: Anatomy And Physiology, By Peter S. Davie, Harry L. Fierstine

Biological Sciences

No abstract provided.

Strategies For Improving The Cytochemical And Immunocytochemical Sensitivity Of Ultrastructurally Well-Preserved, Resin Embedded Biological Tissue For Light And Electron Microscopy, Jan A. Hobot, Geoffrey R. Newman

Scanning Microscopy

Many techniques for processing tissue into resin are available, varying from conventional room temperature to low temperature procedures. The problem is to choose an appropriate method to suit the biological specimen under study. Room temperature approaches with aldehyde and osmium fixation do not give optimal retention of immunoreactivity. Osmium can be removed from sections, but recovery of immunosensitivity is reduced. Osmium post-fixation can be omitted, but heat polymerization of resins causes tissue extraction and loss of immunoreactivity. Alternative techniques rely on the use of milder polymerization methods and avoid osmium. However, while providing an improvement, this alone is not sufficient …

High Voltage Electron Microscopy And Low Voltage Scanning Electron Microscopy Of Human Neoplastic Cell Culture, Marek Malecki

Scanning Microscopy

Improved procedures were developed to correlate cell culture data with the images provided by advanced ultrastructural technologies. These procedures were compatible with the two main types of cellular behavior: adherent, spreading (melanomas, rhabdomyosarcomas) and non-adherent in suspension (leukemias).

The ultrastructure and function of spreading neoplastic cells primarily depend on surface properties of the attaching substrates. Therefore, the films used for cultured cell whole-mount ultrastructural analysis must have adherence features identical to those of standard cell culture vessels. Improved procedures were developed to produce the polystyrene films of required qualities. These films allowed processing of cells for electron microscopy including chemical …

Adsorption Staining Of Freeze-Substituted And Low Temperature Embedded Frog Skeletal Muscle With Cesium: A New Method For The Investigation Of Protein-Ion Interactions, L. Edelmann

Scanning Microscopy

A new adsorption staining method for transmission electron microscopy is described by means of which cellular adsorption sites of alkali-metal ions can be visualized in freeze-substituted and low temperature embedded biological material. The main features of this staining method are: 1) the use of Cs⁺ -ions which are known to accumulate in living cells like K⁺ -ions and 2) the removal of the staining solution from thin sections of the embedded material by centrifugal force. It is shown that sections of freeze-substituted and Lowicryl embedded frog skeletal muscle which has not been treated with chemical fixatives can be …

The Species-Genus Relationship In Antillean Bat Communities, Donald A. Mcfarlane

WM Keck Science Faculty Papers

The ratio of the number of species to the number of genera in an island community has long been recognised as a potential proxy indicator of competitive interaction. An analysis of this relationship in the bat fauna of the Antillean archipelago demonstrates that the observed species-genus ratios are significantly depressed below null-model expectations, and that the magnitude of this depression is inversely proportional to the log of the appropriate island area. These observations are consistent with the hypothesis that interspecific competition may play an important role in structuring Antillean bat communities.

Reproductive Insularity In A Migratory Sparrow: A Field Study Of Lincoln's Sparrow Populations In Southern California, Cin Greyhaven

Theses Digitization Project

Melospiza lincolnii -- San Bernardino and San Jacinto mountain ranges -- migrational return -- Dispersal - Morphometric analysis.

Shrimp Stocking, Salmon Collapse, And Eagle Displacement, Craig N. Spencer, B. Riley Mcclelland, Jack Arthur Stanford

Biological Sciences Faculty Publications

No abstract provided.

Preservation And Immunogold Localization Of Lipids By Freeze-Substitution And Low Temperature Embedding, Wim Voorhout, Ida Van Genderen, Gerrit Van Meer, Hans Geuze

Scanning Microscopy

The success of postembedding immunocytochemistry depends largely on the preparation methods. The requirements for structural preservation and immunocytochemistry are in some cases contradictory. This is especially the case in the study of lipid-rich structures and the localization of lipid components. Earlier work on freeze-substitution has shown that this method is very promising for the preservation of lipids and the immunocytochemical localization of lipids at the electron microscopical level.

In this study we show that freeze-substitution in combination with low temperature embedding in Lowicryl HM20 has fulfilled this promise. Lamellar bodies in alveolar type II cells contain about 90% lipids and …

Diffusion Of Water In Biological Tissues, H. E. Rorschach, C. Lin, C. F. Hazlewood

Scanning Microscopy

A method is presented for obtaining simple approximate solutions for the problem of self-diffusion in an ordered array of obstacles. Our results are compared with some previous exact and approximate solutions, and we find that our method agrees well with the exact results over a large range of the volume fraction of the obstructions. It is shown that there is an important distinction between measurements of the diffusion coefficient by the capillary flow method and the spin-echo method. The modifications for the spin-echo case are given and applied to recent measurements on the anisotropy of the self-diffusion of water in …

Reliability Of Intracellular Water And Ion Distributions As Measured By X-Ray Microanalysis - A Review, Thomas Von Zglinicki

Scanning Microscopy

X-ray microanalysis can be an important tool to reveal the spatial relationships between polyelectrolytes, ions, and water as they occur within cells and tissues in vivo. To reach this goal, at least two of these three closely interrelated variables should be measured independently. Moreover, the absence of systematic errors should be proven.

The present review discusses the probability of artificial ion and water shifts between intracellular compartments due to the growth of dendritic ice crystals much larger than the cross-sectioned remnants commonly seen in frozen-dried sections. Considering the possible mechanism of ice crystal growth it is concluded that ions and …

Cryopreparation Of Tissue For Clinical Applications Of X-Ray Microanalysis, Godfried M. Roomans

Scanning Microscopy

A number of diseases is associated with changes in ion and/or water distribution at the tissue or cell level, and X-ray microanalysis can be used to investigate the relationship between the disease process and the changes in elemental distribution. For analysis of diffusible elements by X-ray microanalysis, the tissue has to be prepared by cryotechniques. To carry out studies of this kind in a clinical environment poses a number of problems. Some of these problems occur already before the tissue is frozen, others are caused by the practical and ethical limitations that are imposed on the freezing method itself when …

Specimen List, Lila Alejandra Sainz-Bacherer

Division of Mammals - Field Notes and Catalogs

No abstract provided.

Freezing: Facts And Hypothesis, J. Dubochet, K. Richter, H.-V. Roy, A. W. Mcdowall

Scanning Microscopy

Hexagonal ice crystals formed in frozen biological specimens are large and branched. They can produce severe structural damage by solute segregation but there are also cases where they seem to cause only minor damage. When cooling is more rapid, cubic ice crystals can be formed. These are small and in general, they cause little damage. These observations can be readily explained with the hypothesis that large hexagonal ice crystals can originate from the rewarming induced transformation of a large number of cubic ice crystals. This transformation would take place without significant solute displacement.

The Ultrastructure Of Cryo-Sections And Intact Vitrified Cells - The Effects Of Cryoprotectants And Acceleration Voltage On Beam Induced Bubbling, P. M. Frederik, P. H. H. Bomans, M. C. A. Stuart

Scanning Microscopy

Chemically fixed pancreas was infiltrated with various cryoprotectants to obtain homogeneously vitrified samples upon cooling. The suitability of these samples for cryo-ultramicrotomy was tested. Contrast was hardly detectable initially in thin cryo-sections but increased upon irradiation, irrespective of the cryoprotectant (glycerol, propylene glycol, methanol) used. Contrast and beam damage were analyzed in vitrified thin films from collagen, phospholipid vesicles and various concentrations of glycerol. Glycerol increased the beam sensitivity of both collagen and phospholipid vesicles, but diminished the contrast between matrix and lipid vesicles or collagen fibers. The effects of glycerol as observed in thin films explain some of the …

Aldehyde Fixation Causes Membrane Vesiculation During Platelet Exocytosis: A Freeze-Substitution Study, E. Morgenstern

Scanning Microscopy

Despite a plethora of reports on the ultrastructure of secretory granule release by exocytosis, the release of coagulant activity from stimulated platelets is still being attributed to membrane vesiculation. Membrane vesiculation and the formation of myelin figures have been shown to be artifacts of glutaraldehyde GA fixation. Cells fixed by direct osmium or rapid freezing are free of such structures. Yet there is still doubt that rapid freezing interferes with vesiculation process. This study has addressed this issue by examining: (1) whether freezing and freeze-substitution affects membrane vesiculation, (2) whether paraformaldehyde-fixation also induces the phenomenon, and (3) whether the aldehyde …

An Evolutionary Perspective On Salt, Hypertension, And Human Genetic Variability, Fatimah Linda Collier Jackson

Department of Biology Faculty Publications

Natural selection for electrolyte conservation has likely been the norm throughout human evolutionary history. However, the current patterns of excessive dietary salt intake create the potential for salt overload. Under these conditions, hypertension may be considered an expected pathological response to an evolutionarily new constraint. The transatlantic Middle Passage may have created a genetic bottleneck for salt conservation in African-Americans. Although the initial consequences of this important historical event probably constricted genetic variability and further magnified the potential for salt-sensitive hypertension, the Middle Passage undoubtedly also served as a more generalized major source of environmental stress and may have stimulated …

Evolution Of Life History Parameters In Animals With Indeterminate Growth, Particularly Fish, Eric Charnov, David Berrigan

Biology Faculty & Staff Publications

Optimal life history theory is used to understand the Beverton-Holt dimensionless numbers for fish life histories

A Taxonomic Study Of Variation In Leptochloa Fascicularis (Lam.) Gray In The Central Great Plains, Todd A. Templeton

Biology Faculty Publications

The morphology of Leptochloa fascicularis (Lam.) Gray (Poaceae) was studied in 25 locations in eastern and central Nebraska to determine if this grass was separable into two distinct taxa as suggested in several recent sources. Field collections were supplemented with herbarium specimens from other parts of the Central Great Plains. Glume and lemma lengths, the characters used in published keys, provided no separations useful in dividing the material into two species or varieties. However, individual local populations exhibited significant differences from each other in these characters. Such local differences appear to be reasonable given the high degree of inbreeding that …

Diurnal Variation In Mass, Metabolic Rate, And Respiratory Quotient In Anna's And Costa's Hummingbirds, Donald R. Powers

Faculty Publications - Department of Biological & Molecular Science

To examine how hummingbirds that do not enter torpor at night store and utilize energy, open-circuit respirometry and a strain gauge were used to measure daily variation in 0 2 consumption (Vo2 ), C02 production, respiratory quotient (RQ), and body mass in Anna's hummingbird, Calypte anna, and Costa's hummingbird, Calypte costae. During the day, Vo2 was highly variable primarily because of dif ferences in activity among individuals. At night Vo2 varied little between individuals, but mean Vo2 was more than two times that predicted from body mass for resting, postabsorptive birds. F0.85), indicating the use of carbohydrate as a …

Osmotic Effects On Mitochondria From Two Species Of Amphibian, Bufo Marinus And Rana Catesbeiana, Jeff Duerr

Faculty Publications - Department of Biological & Molecular Science

The effects ql ionic and/or osmotic change on skeletal muscle mitochondrial performance were investigated. Two substrates, pyruvate and glutamate, and variation in osmotic pressure from 205 to 360 mosm in KCl or mannitol/sucrose media had no effect on maximal respiratory rate (state 3) or coupling (respiratory control ratio) in either species. Over an equivalent range of osmolalities associated with dehydration, organismic maximal 02-consumption rates are severely diminished with increasing osmolalities. The data do not support a mitochondria/limit to organismic 02 consumption under dehydration. There were interspecies differences in state 3 respiration and coupling that were similar to differences noted in …

Decreased Sprint Speed As A Cost Of Reproduction In The Lizard Scelopours Occidentalis: Variation Among Populations, Barry Sinervo, Richard Hedges, Stephen C. Adolph

All HMC Faculty Publications and Research

Decreased mobility of gravid females is thought to be an important cost of reproduction in lizards. We measured sprint speeds of female western fence lizards (Sceloporus occidentalis Baird and Girard) before and after they had oviposited. Females from two California populations were about 20% slower when gravid, females from an Oregon population were about 30% slower, and females from a Washington population were about 45% slower, compared to their speeds after recovering from reproduction. The decrease in sprint speed persisted for several weeks after oviposition, suggesting that reproduction impairs sprint performance by affecting body condition in addition to the burdening …

Patterns Of Hydroxyproline Excretion In Ovariectomized And Estrogen Treated Rats, Gregg Horras

Presidential Scholars Theses (1990 – 2006)

If nuclear binding sites for estrogens exist in bone cells, then the origin of estrogen-deficiency-induced osteopenia may be at the level of bone matrix protein synthesis. Since collagen is the most abundant protein in the bone matrix, and since hydroxyproline is an imino acid nearly exclusive to collagen, a monitoring of the metabolism of hydroxyproline in ovariectomized and estrogen treated rats may provide insight into the patterns of estrogen-deficiency-induced osteopenia. The purpose of our study was to test the hypothesis that ovariectomy will increase urinary hydroxyproline excretion in the rat and that this increase will be reversed by estrogen treatment …

Foreword, Scott F. Gilbert

Biology Faculty Works

No abstract provided.

Long Range Organization Of Alphoid Sequence On Human Chromosome 21, Malini Chawla

Master's Theses

No abstract provided.