Thesis (Ph. D.)--University of Wisconsin--Madison, 1946. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 89-93).

Thesis (M.S.)--Utah State University, 1968. / Title from title screen (viewed Aug. 14, 2009). Department: Wildlife Resources. Includes vita. Includes bibliographical references. Archival copy available in print.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 65-72).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 210-215).

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 82-87). Also available on the World Wide Web.

Thesis (Ph.D.)--University of Massachusetts Boston, 2005. / Title from PDF title page. Available through UMI ProQuest Digital Dissertations. Includes bibliographical references (p. 82-102). Also issued in print.

Thesis (Ph.D.)--Montana State University--Bozeman, 2007. / Typescript. Chairperson, Graduate Committee: John P. Miller. Includes bibliographical references (leaves 152-171).

Thesis (M.S.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 27, 2007) Includes bibliographical references.

Thesis (Ph.D)--Boston University / Characteristics of deoxyribonuclease II from calf thymus and spleen were described and verified by the following experimental procedures. Nuclei from calf thymus were prepared free of cytoplasm both by washing homogenized tissue in sucrose solutions, and by density gradient centrifugation in organic solvents. The action of the enzyme from nuclei and from a thymus homogenate was found to be similar when measured by light scattering and hyperchromic shift. Deoxyribonuclease II from calf spleen was purified by ammonium sulfate precipitation. Further purification of the enzyme on column chromatography resulted in fractions similar to those reported in the literature. The effect of sodium sulfate on the activity of splenic DNase II, purified by ammonium sulfate precipitation, was measured by the production of acid-soluble nucleotides from deoxyribonucleic acid during hydrolysis. The effect of the sulfate ion was also measured by viscometry, as was the effect of magnesium chloride, manganese chloride, sodium citrate and iodoacetic acid. The substances were all found to be inhibitory, which is in agreement with the results reported in the literature. Deoxyribonucleases active at an acid pH were extracted from representatives of four invertebrate phyla (Echinodermata, Mollusca, Arthropoda and Annelida) and compared with vertebrate deoxyribonuclease II with respect to ionic requirements and pH optima. [TRUNCATED]

In situ measurements of the fertilization success of broadcast spawning marine invertebrates have been conducted mainly on shallow subtidal echinoderm and coral species. In this study, field fertilization success was measured for two infaunal, intertidal polychaetes Arenicola marina and Nereis virens. Both species are epidemic spawners, with populations of A. marina spawning over a few days in autumn while N. virens spawns in early spring. The fertilization success of female Arenicola marina is highly variable, ranging from 0 to 100%, and is determined by male spawning density. It is hypothesised that fertilization success over the entire spawning period is the result of an accumulation of fertilizations each day in the spawning period. Fertilization success was measured indirectly in Nereis virens by transplanting oocytes into the field. At least two spawning periods occurred for the population studied here. Fertilization success was uniformly high during the first period, and in the second fertilization success was highest among those eggs located high in the water column as opposed to those at substratum level. The fertilization strategies of these polychaetes are discussed in the light of these results. Comparative laboratory experiments were performed on factors that affect fertilization success in Arenicola marina. Nereis virens, Asterias rubens and Echinus esculentus, including sperm:egg ratio, sperm-egg contact time and sperm concentration. The extent to which each of these factors affects fertilization success varies with species, and this is explained by gamete attributes and mathematical models. Gamete longevity significantly affects fertilization success, and eggs and sperm of Arenicola marina are extraordinarily long lived compared to those of the other species studied here and elsewhere. Eggs are viable for 5 days after spawning, while dilute sperm remains capable of fertilizing eggs for more than 48 hours. The laboratory data are discussed in terms of the fertilization strategies of each of the species.