Thesis (M.S.)--Oregon State University, 1997. / Typescript (photocopy). Includes bibliographical references (leaves 127-134). Also available on the World Wide Web.

Thesis (Ph.D.)--Ohio University, August, 2003. / Title from PDF t.p. Includes bibliographical references (leaves 171-179)

Thesis (M.A.)--Humboldt State University, 2006. / Includes bibliographical references (leaves 52-56). Also available via Humboldt Digital Scholar.

Thesis (M.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / Serotonin (5-hydroxytryptamine), one of the biologically active amines, has been found in rather large quantities in the dorsal skin of Rana pipiens. Quantitative determination of the endogenous levels of the amine in the whole dorsal skin homogenate extracts were made on a Farrand spectroflourometer, and ranges of 120-200 micrograms per gram of fresh tissue were established. Comparison of whole skin homogenates and homogenates of just the dorsal cutaneous ridges, or dermal plicae, indicated that the amine is localized in these ridges. Acid treatment of the denser more fibrous portions of the homogenate prior to extraction more then noublcc the yields of serotonin. This result showed that the amine is found primarily in the deeper portions of the skin, very likely in the poison glands which are concentrated in the dermal plicae. Skin homogenates were also studied to determine if serotonin is actually synthesized in the skin. A precursor of the amine, 5-hydroxytryptophan, decarboxylates in tne presence of 5-hydroxytryrtophan decarooxylase to produce the amine. 5-hydroxytryrtophan was incubated with the homogenate, under nitrogen, for two hours to determine enzymic activity. Under the conditions of the experiment, no enzymic activity could be shown, indicating that serotonin is not produced in the skin of the frog in detectable amounts. The fact that serotonin levels are so high, and the lack of enzymic activity indicates that once synthesized serotonin is stored in an inactive form or is synthesized elsewhere and transnorted to the skin. / 2031-01-01

No abstract available. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1977

No description available.

Festival de Innovación Educativa de la UPC. Ponente: Dr. Roberto Elias / El primer FIE de la UPC es un espacio de docentes para docentes, en donde se compartirán las estrategias innovadoras de aprendizaje que se han venido aplicando en los últimos meses de educación online. Es una oportunidad para intercambiar conocimiento, seguir aprendiendo y atrevernos a innovar como parte del proceso de enseñanza y aprendizaje.

Mosquitoes are considered to be the deadliest animals in the world due to the diseases they spread. Naturally, most research centers around anthropophilic disease vector mosquitoes such as Aedes aegypti or Anopheles gambiae. However, mosquitoes can feed on, and pose a threat to, more than humans. In fact, mosquitoes can specialize in feeding on a wide variety of hosts, including ectotherms such as amphibians and reptiles. Culex territans is a mosquito that feeds primarily on amphibians and reptiles and is known to transmit parasites to its hosts. However, little else is known about this mosquito. This work dives into the biology, physiology, and vector potential of this mosquito species to provide critical insights into understanding the evolution of feeding on endotherms as well as the importance of Cx. territans to amphibian health. The first study investigates activity patterns and feeding behaviors as well as the potential cues that may attract this mosquito to its hosts. We also compare transcriptomics and anatomy of the heads of three Culex species. The second study compares three Culex species' thermopreference and host-seeking to understand the effects of the differences of geographical distribution and preferred hosts. The last three studies determine the presence of ranaviruses, giant anuran trypanosomes, and the fungus Batrachochytrium dendrobatidis at Mountain Lake Biological Station and explore the potential role of Cx. territans in transmitting these pathogens. Overall, this work provides insights into the biology of Cx. territans and the implications it may have for understanding endotherm-feeding mosquitoes and amphibian disease epidemiology. / Doctor of Philosophy / We are all familiar with the annoying buzzing sound and itching bite of a mosquito. But mosquitoes are more than irritating: they are considered the deadliest animal in the world because of their ability to spread deadly diseases such as malaria and yellow fever to humans. However, not all mosquitoes bite humans. In fact, mosquitoes can feed on the blood of just about any animal, including worms. This work focuses on Culex territans, the northern frog-biting mosquito, which feeds mostly on the blood of amphibians, like frogs and toads. This fascinating mosquito species is present around the world, living in freshwater ponds alongside frogs, but we know very little about it. For example, how does a frog-biting mosquito find a frog host to bite? Once the mosquito bites, how is it able to feed on cold, thick blood through a tiny straw that makes up its mouthparts? While it is feeding, is it spreading diseases that could harm the frog? Because amphibians are experiencing extinctions worldwide, it is important to know if mosquitoes could be involved in their demise. These questions inspired this work to better understand the biology of Cx. territans and to shed light on the biology of other disease-spreading mosquitoes.

No description available.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xiv, 138 p. : ill. Advisor: Thomas C. Grubb, Dept. of Evolution, Ecology, and Organismal Biology. Includes bibliographical references (p. 129-138).