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Full-Text Articles in Life Sciences

Defining Amino Acid Requirements Of Pregnant Sows: Challenges And Opportunities, Christian D. Ramirez-Camba Jan 2022

Defining Amino Acid Requirements Of Pregnant Sows: Challenges And Opportunities, Christian D. Ramirez-Camba

Electronic Theses and Dissertations

The efficient use of protein in animal production is dependent on the protein supply and its constituent amino acids (AA) in relation to the animal's needs. Excess AA are deaminated, and the resulting nitrogen (N) is excreted, whereas suboptimal AA intake reduces animal performance. Both increased nutrient excretion and decreased animal performance reduce the overall efficiency of the production unit. In sows, AA requirements should be adequate for optimizing reproductive performance, as measured, for example, by the number of pigs produced per sow per year while limiting N excretion. There is a desire to feed pregnant sows AA levels that …


The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang Aug 2021

The Impacts Of Climate Change On The Gulf Of Maine Northern Shrimp (Pandalus Borealis) Distribution, Reproduction, And Life, Hsiao-Yun Chang

Electronic Theses and Dissertations

The Gulf of Maine northern shrimp (Pandalus borealis) once supported a significant winter fishery for the Gulf of Maine (GOM). Although the shrimp fishery is not comparable to the lobster business, it provided fishermen and many coastal communities jobs and incomes in winters after lobster seasons. However, a moratorium has been put on the shrimp fishery since 2014 due to record low population abundance and perceived recruitment failures. The recruitment failures have been correlated with warming water temperatures over the past decade. The GOM has been recognized as experiencing rapid warming as a result of global climate change. …


Optimization Of Reproductive Success In Beef Cattle By Implementation Of Estrus Resynchronization, Nutritional Management, And Evaluation Of Disease Prevalance, Kaitlin M. Epperson Jan 2019

Optimization Of Reproductive Success In Beef Cattle By Implementation Of Estrus Resynchronization, Nutritional Management, And Evaluation Of Disease Prevalance, Kaitlin M. Epperson

Electronic Theses and Dissertations

The beef industry is a unique community of operations that employ different management techniques to accomplish a similar goal. Like other facets of animal agriculture, profitability of the beef industry is heavily reliant upon the implemented management practices. Reproductive efficiency is an area of management that has great potential to positively influence the success of beef production. Through the use of reproductive technologies such as estrus synchronization and AI, a greater percentage of females can become bred to superior sires, breeding and calving seasons can be shortened, calf uniformity increased, and economic return maximized (Odde, 1990; Rodgers et al., 2012; …


Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright Dec 2018

Temperature And Polyunsaturated Fatty Acid’S Effect On Daphnia Magna Reproduction, Mark Albright

Electronic Theses and Dissertations

Organisms adapt to their environments by adjusting their biochemistry and physiology; such adaptation is limited by resource availability and physiological constraints. The freshwater crustacean Daphnia magna inhabits a wide range of environments and must survive and reproduce within a range of temperatures. One limit to low-temperature adaptation is thought to be the availability of unsaturated fatty acids necessary to maintain proper fluidity of cellular membranes. D. magna maintained at 10 ºC on a diet poor in unsaturated fatty acids have been observed to produce clutches that fail to develop. However, this has not been observed on a diet rich in …


Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain May 2018

Polyp To Population: A Tale Of Two Corals, Christopher T. Fountain

Electronic Theses and Dissertations

Deep-sea corals are of conservation concern in the North Atlantic due to prolonged disturbances associated with the exploitation of natural resources and a changing environment. As a result, the recovery rates of deep-sea coral communities are of heightened interest. These recovery rates are suggested to be on the order of decades to millennia, based on slow growth rates and longevity, of various deep-sea coral species. In 2014 and 2017 two research cruises in the Gulf of Maine, collected samples of two locally dominant species, Primnoa resedaeformis and Paramuricea placomus. These specimen collections were coupled with video surveys, conducted by …


Improving Techniques To Study Equine Cervical Mucociliary Clearance, Melissa A. Hawkes May 2018

Improving Techniques To Study Equine Cervical Mucociliary Clearance, Melissa A. Hawkes

Electronic Theses and Dissertations

Bacterial uterine infections inflict major losses on the equine breeding industry. These infections usually arise from bacteria introduced at breeding. Micro-currents propelled by ciliated cells between the folds of the uterus and cervix have been proposed as a means by which contaminants are expelled. Previous data have shown possible ciliary micro-currents propelling carbon particles, occasionally rotating, through cervical folds. However, adherence to the epithelium may have interfered with movement of carbon in these studies. Therefore, we tested potentially non-adherent substances to reveal ciliary micro-currents on the equine cervix under high magnification video-endoscopy. We hypothesized that polyethylene green microspheres 1 - …


Evaluation Of Alternative Weed Hosts And Management Strategies For Soybean Cyst Nematode In South Dakota, Pawan Basnet Jan 2018

Evaluation Of Alternative Weed Hosts And Management Strategies For Soybean Cyst Nematode In South Dakota, Pawan Basnet

Electronic Theses and Dissertations

The soybean cyst nematode (SCN; Heterodera glycines, Ichinohe) is an important pathogen of soybean in South Dakota which causes significant yield losses. SCN has been found in 30 South Dakota counties as on 2017 and is estimated to cause yield loss of 1.9 Metric tons (Mt) annually. SCN has diverse crop and weed hosts as it can reproduce in several crops and weeds. The presence of Heterodera glycines (HG) types can reduce the effectiveness of SCN-resistant cultivars and the HG types reproduction on weed hosts can negate the effectiveness of crop rotation by continued build-up in the field. This …


Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich Jan 2017

Local And Systemic Actions Of Gnrh Relating To Estradiol And Associated Reproductive Parameters In Beef Cattle, Jerica J.J. Rich

Electronic Theses and Dissertations

In cattle, estradiol is responsible for modulating many mechanisms involved in successful reproduction. Specifically estradiol is the primary signal for the initiation of standing estrus (Allrich, 1994), and cattle expressing estrus prior to fixed time AI (FTAI) have been reported to have increased preovulatory estradiol concentrations (Perry and Perry, 2008) and increased pregnancy success compared to animals that did not exhibit estrus (Richardson et al., 2016). Gonadotropin releasing hormone, classically, stimulates estradiol production via the two-cell two-gonadotropin hypothesis (Fortune and Quirk, 1988), and GnRH administered systemically in small doses (5 μg) has been reported to elicit an LH pulse similar …


Characterizing The Developmental And Reproductive Toxicities Of Cannabidiol And Δ9-Tetrahydrocannabinol, Dennis Ray Carty Jan 2017

Characterizing The Developmental And Reproductive Toxicities Of Cannabidiol And Δ9-Tetrahydrocannabinol, Dennis Ray Carty

Electronic Theses and Dissertations

Medical marijuana is legal in twenty-nine of the United States and an additional nineteen states have passed legislation for cannabidiol (CBD) treatment of drug-resistant epilepsy, such as Dravet Syndrome (DS) which is diagnosed in children as young as two months. While CBD has shown anecdotal and recently clinical trial efficacy in reducing seizure frequency in DS patients, little is known about the potential adverse side-effects on child physiology, brain development, adult disease, or subsequent generations. Moreover, CBD is rarely administered without including low concentrations of Δ9-tetrahydrocannabinol (THC). The goal of this project is to characterize the relative morphological, behavioral, reproductive, …


Highly Seasonal Reproduction In Desmophyllum Dianthus From The Northern Patagonian Fjords, Keri Feehan Mar 2016

Highly Seasonal Reproduction In Desmophyllum Dianthus From The Northern Patagonian Fjords, Keri Feehan

Electronic Theses and Dissertations

The purpose of this study was to determine the basic reproductive biology and seasonality of the Patagonian fjord coral Desmophyllum dianthus. Desmophyllum dianthus is a deep-sea solitary scleractinian found throughout the world’s oceans and an important benthic habitat builder. The Chilean Patagonian fjords are the only known location where this species occurs >50 m and thus are the only place to collect samples efficiently, effectively and economically. Corals were collected via SCUBA approximately every three months (when conditions permitted) from August 2012 to September 2013 from three sites within the Northern Patagonian fjords – Lilihuape (n=76) and Punta Huinay …


Macgillivray's Seaside Sparrow (Ammodramus Maritimus Macgillivraii) Breeding Biology & Population Density At Tom Yawkey Wildlife Center, Yianni P. Laskaris Jan 2016

Macgillivray's Seaside Sparrow (Ammodramus Maritimus Macgillivraii) Breeding Biology & Population Density At Tom Yawkey Wildlife Center, Yianni P. Laskaris

Electronic Theses and Dissertations

MacGillivray's Seaside Sparrow (Ammodramus maritimus macgillivraii) is a coastal marsh species sensitive to habitat alteration and threatened by coastal wetland loss. Data on seaside sparrow distribution, breeding success, and critical habitats are lacking in South Carolina. To better understand the demographics and incubation behavior of the species, I monitored breeding success, densities, song output, and presence of predators at three 7-hectare plots at the densest known population in the state. I also placed temperature data-loggers in a subset of nests to discern any links between incubation behavior and nest fate. Densities varied from a low of 5 birds/ha in a …


Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc Jan 2013

Benzo[A]Pyrene Effects On Fundulus Heteroclitus Reproductive Endpoints, Frank Booc

Electronic Theses and Dissertations

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) that modulates aromatase enzyme function and, thus, potentially interrupts normal reproductive function. The aim of this study was to use a fish model, Fundulus heteroclitus, to assess whether BaP exposure adversely impacted reproduction. Adult fish were exposed to waterborne BaP concentrations of (0, 1 or 10 μg/L) for 28 days. Males and females were combined for the second half of the exposure (days 14-28) in order to quantitate egg production and fertilization success. Egg fertilization and subsequent hatching success of F1 embryos was significantly decreased by 10 μg/L BaP. In males, both …


The Effects Of Intracerebroventricular Leptin On Milk Availability In Lactating Rats, Brittany Lynita Moore Dec 2012

The Effects Of Intracerebroventricular Leptin On Milk Availability In Lactating Rats, Brittany Lynita Moore

Electronic Theses and Dissertations

Reports have linked energy balance along with adipocyte derived leptin action to improved fertility. Recent evidence indicates that leptin hormone is present in breast milk and leptin receptors are well expressed in mammary epithelial cells. The hypothesis that insufficiency of leptin restraint in the hypothalamus may underlie infertility in rodents and the failure of lactating breast to express adequate amount of milk was tested. Female Sprague-Dawley rats were injected leptin through intracerebroventricular cannulation (ICVC) of the third ventricle. Female rats were mated with stud males and observed throughout gestation. Compared to the control groups, leptin treatment increased prolactin levels in …


Epigenetic Effects Of Benzo(A)Pyrene In Fundulus Heteroclitus And Danio Rerio, Xiefan Fang Jan 2011

Epigenetic Effects Of Benzo(A)Pyrene In Fundulus Heteroclitus And Danio Rerio, Xiefan Fang

Electronic Theses and Dissertations

DNA methylation is one of the epigenetic mechanisms that controls gene expression and is vulnerable to early life environmental toxicant exposures. Our goal was to use two fish models, Fundulus heteroclitus and Danio rerio (zebrafish), to study the benzo(a)pyrene (BaP) effects on DNA methylation status and whether the alterations could contribute to BaP-mediated reproductive and developmental toxicities. Initially, we used Fundulus to study BaP effects on glycine N-methyltransferase (GNMT) expression throughout development. Fundulus embryos were exposed to waterborne BaP at nominally 10 or 100 μg/L and both GNMT mRNA expression and enzyme activity were measured. Quantitative PCR and whole mount …