Life Sciences Commons^™

Alterations In Calcium Homeostasis And The Insulin-Like Growth Factor Signaling Pathway Induced By Carcinogenic Polycyclic And Halogenated Aromatic Hydrocarbons In Human Mammary Epithelial Cells, Stacey L. Tannheimer

Pharmaceutical Sciences ETDs

Breast cancer is a major health concern for women, with only a small percent of the risk factors currently identified. It has been estimated that environmental factors may contribute to up to 80% of breast cancer cases. Many environmental carcinogens, such as polycyclic and halogenated aromatic hydrocarbons (PAHs and HAHs), are proven mammary carcinogens in animal models. Therefore, these studies were conducted to elucidate potential roles of PAHs and HAHs in alterations in known signaling pathways in human mammary epithelial cells (HMEC). Carcinogenic PAHs have previously been shown to produce sustained alterations in the calcium (Ca2') homeostasis of lymphocytes Therefore, …

Physiology And Ecology Of Dispersal Polymorphism In Insects, Anthony J. Zera, Robert F. Denno

Anthony Zera Publications

Studies of dispersal polymorphism in insects have played a pivotal role in advancing our understanding of population dynamics, life history evolution, and the physiological basis of adaptation. Comparative data on wing-dimorphic insects provide the most definitive evidence to date that habitat persistence selects for reduced dispersal capability. The increased fecundity of flightless females documents that a fitness tradeoff exists between flight capability and reproduction. However, only recently have studies of nutrient consumption and allocation provided unequivocal evidence that this fitness trade-off results from a trade-off of internal resources. Recent studies involving wing-dimorphic insects document that flight capability imposes reproductive penalties …

The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin

Biological Sciences Theses & Dissertations

The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …

Use Of Fluorescence Microscopy In An Assay Of Sperm Density For The Gorgonian Coral, Plexaura Kuna, Timothy D. Swain, K. Kim, H. R. Lasker

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The density of sperm in the water column during the broadcast spawning events of marine invertebrates is often undetermined or reported in terms of fertilization potential. The density of sperm during such events can be determined by directly counting numbers of spermatozoa using a modification of the acridine orange direct count (AODC) technique for enumerating bacteria. A number of variables in the handling and processing of samples may bias estimates. Sample collection in glass and rapid fixation and filtration are necessary for reproducible estimates. Once filtered, samples are stable for many months, and counts on filters that were poorly stained …

Development Of Gilts And Boars For Efficient Reproduction, Donald G. Levis, Vernon D. Leibbrandt, Dale W. Rozeboom

Department of Animal Science: Faculty Publications

Successful introduction of replacement gilts and boars into the breeding herd is an important aspect of breeding herd efficiency. To attain herd efficiency, females must ovulate adequate numbers of viable ova, express estrus, show willingness to mate, and conceive in a regular manner. Males must produce adequate numbers of fertile spermatozoa, possess ability and show willingness to mate, and produce high-conception rates. If these qualities are properly developed, pregnancy rate and litter size will be maximized.

The Effect Of Disturbance On The Reproduction And Management Of Captive Cranes, Claire M. Mirande, James W. Carpenter, Ann M. Burke

Proceedings of the North American Crane Workshop

A retrospective analysis of egg laying histories and observations of crane pairs at the International Crane Foundation and the Patuxent Wildlife Research Center indicates that disturbance associated with captivity has adverse impacts on captive breeding. Females on public display laid significantly fewer eggs than those off display (P < 0.05). Crane pairs moved to other pens (other than adjacent pens) or hetween facilities laid slightly fewer eggs than those birds which were not moved. although the results were not statistically significant (P = 0.188). Pen design and construction also appeared to have adverse impacts on breeding. In addition, human activities, intraspecific interactions, and rearing methods influence a bird's response to disturbance, and, therefore, these factors must also be considered in an effective crane management program. Modifying procedures to minimize disturbance, timing necessary disturbances after the breeding and molt seasons, and carefully monitoring birds for signs of stress can result in increased reproductive potential for captive, endangered cranes.

Ubiquitin-Mediated Proteolysis During Gametogenis In Chlamydomonas Reinhardtii, Hall Thomas Mcgee

Honors Theses

Scientists in the field of cell biology have focused considerable attention on a unicellular species of green algae known as Chlamydomonas reinhardtii. This organism is relatively common in bodies of fresh water and some types of soil, but most of the attention is due to its value as a model for biochemical studies. This laboratory has undertaken a broad study of the species including exploration into a special class of proteins, called heat shock proteins, and certain biochemical processes of the organism. The work herein described is a part of this latter study, and also a preliminary step in a …

Ec97-219 1997 Nebraska Swine Report, Duane Reese

University of Nebraska-Lincoln Extension: Historical Materials

The 1997 Nebraska Swine Report was prepared by the staff in Animal Science and cooperating Departments for use in Extension, Teaching and Research programs. This publications deals with research on swine reproduction, breeding, health, nutrition, economics, and housing.

Ec97-274 Management Of Replacement Gilts For Efficient Reproduction, Donald G. Levis

University of Nebraska-Lincoln Extension: Historical Materials

Successfully introducing replacement gilts into the breeding herd is an important aspect of breeding herd efficiency. To attain herd efficiency, females must ovulate adequate numbers of viable ova, express estrus, show willingness to mate and conceive in a regular manner. If these qualities are properly developed, pregnancy rate and litter size will be maximized. A gilt development and management program needs to be designed for gilts from birth to farrowing their first litter.

1997 Nebraska Swine Report, Duane E. Reese

University of Nebraska-Lincoln Extension: Historical Materials

This publication was prepared by the staff in Animal Science and cooperating Departments for use in Extension, Teaching and Research programs. It deals with the results that were done in reproduction, breeding, health, nutrition, seconomics and housing of swine.

G97-1324 Beef Cattle Implant Update, Dicky D. Griffin, Terry L. Mader

University of Nebraska-Lincoln Extension: Historical Materials

This NebGuide discusses the mechanism of action and use strategies for growth promoting implants, including expected responses and cost analysis.

Introduction

Growth promoting implants have been used extensively in beef production for over 30 years. Significant changes in implants and implanting strategies have occurred. Prior to 1987, available implants were estrogenic agents which metabolically enhanced nutrient use to enhance growth. These products improved feed efficiency 5-10 percent and daily gains from 5-15 percent. In 1987, the androgenic (tissue building) agent, trenbolone acetate, was approved for use in growth promoting implants. This compound had an additive effect with existing estrogenic implants. …

Mp68 1996-98 Dairy Report

University of Nebraska-Lincoln Extension: Historical Materials

Annual Report of University of Nebraska-Lincoln Dairy Research for 1997-1998. Topics include:

Time of Initiating Dietary Fat Supplementaion on Lactation and Reproduction

A Soyhull:Soy Lecithin Soapstock Mixture for Early Lactation Dairy Cows

Nonenzymatically Browned Soybeans for Dairy Cattle

Feather and Blood Meal Combination for Lactating Dairy Cows

Impact of Nonfiber Carbohydrate Concentration on Forage Fiber Digestion

Sulfite Liquor-Treated Meat and Bone Meal for Dairy Cows

The OTHER Causes of Infectious Diseases

Test Day Genetic Evaluations

Income and Herdlife

Maternal Genetic and Cytoplasmic Effects in Dairy Cattle

Financial and Management Survey of Nebraska Dairy Producers

Free-Stall Design and Maintenance

Horizontal Silos …