Global ETD Search

1	INSIGHTS INTO THE ECOLOGY OF VESPERTILIONIDAE THORUGH SKULL MORPHOLOGY AND ROOST SELECTION Matthew S Dunn (17552733) 08 December 2023 (has links) <p dir="ltr">Bat population numbers are declining in the Midwestern United States. Reasons for decline are multifaceted (habitat degradation, fatalities at wind turbines, White Nose Syndrome, and declining insect populations), and many species are listed as endangered (Myotis sodalis, Myotis septentrionalis, Perimyotis subflavus). Other species in the Midwestern United States have no conservation status (Eptesicus fuscus), or are only listed as a species of concern (Lasiurus cinereus, Lasiurus borealis, Lasionycteris noctivagans). Bats play a crucial role in our ecosystems, providing both ecological and economic benefit as pollinators and insect population regulators. Thus, conserving these species is vital. To gain better insight into the ecology of Midwestern bat species I studied five species in two respects. First, I investigated the availability of roosts for a colony of endangered Myotis sodalis near Indianapolis. This colony has withstood high levels of urbanization and habitat degradation. Therefore, understanding what aspects of the roosting area has allowed for continued use by the colony is crucial for future conservation efforts. I used an Akaike’s Information Criteria approach to rank models that best differentiate between the current roosting area and surrounding landscape. I identified that the roosting area contained a greater number of large standing dead trees (Snags >42.6 cm) that are able to serve as primary roosts for the colony. These results demonstrate that a colony of Indiana bats may be able to withstand urbanization if they have enough large DBH snags available in the area. Future conservation efforts in a heavily urbanized environment should focus on the maintaining large snags as primary roosts. Second, I studied the morphological variation of four species (Lasiurus cinereus, Lasiurus borealis, Lasionycteris noctivagans, and Eptesicus fuscus) to parse out differences that may lead to niche specialization. These four species share habitat and foraging range and therefore may directly compete for resources. However, despite declining insect populations these four species have moderately stable populations. I collected approximately 30 craniums and mandibles for each species and compared the linear size differences between landmarks and the overall shape variation from these landmarks. Due to different phylogenies and body sizes, the four species were different from one another in all 24 linear measurements. In regards to shape variation, the Eptesicini bat craniums had characteristics of more gracile species. In addition, the mandibles of Eptesicini were highly distinct. Lasionycteris noctivagans was the least durable and Eptesicus fuscus had 10 specialization for hard bodied prey consumption. These results suggest potential niche specialization due variation in morphology.</p> Behavioural ecology Animal structure and function Vertebrate biology Roost Selection Morphology Indiana Bat Myotis sodalis Vespertilionidae Ecomorphology
2	Magnetic Resonance Imaging Guided Neuromodulation of Gastric Physiology Kun-Han Lu (6615527) 25 June 2020 (has links) The stomach is a digestive organ in the gastrointestinal tract that regulates food intake and paces digestion of nutrients and fluids. The emptying and motility patterns of the stomach are crucial rate-determining processes in maintaining energy homeostasis in the body. Dysregulation of gastric functions often leads to distressing conditions such as gastroesophageal reflux diseases, functional dyspepsia, gastroparesis and obesity. Gastric disorders affect more than 60 million people in the US, producing significant medical and economic burden. These diseases are often chronic and greatly compromise quality of life. As the causes of these diseases remain largely unknown, effects of current pharmacological, dietary, or surgical treatments are often dismal. In this regard, neuromodulation of peripheral nerves emerges as a promising electroceutical therapy for remedying gastric disorders. However, therapeutic effects were shown to be modest, largely due to the inability to validate or calibrate the efficacy and stability of neuromodulation methods with appropriate physiological readouts. To address these problems, here I developed a non-invasive, repeatable online high-resolution magnetic resonance imaging protocol, empowered with advanced image processing algorithms, to track gastric emptying, antral motility, pyloric motility, intestinal filling and absorption in a rat model. The protocol can be used to guide tuning and optimization of stimulation parameters of neuromodulation without perturbing ongoing and spontaneous physiology. The proposed technology and findings are expected to pave the way for the use of gastric MRI to evaluate the efficacy of therapeutics in treating gastric disorders under both preclinical and clinical settings. Physiology Computer Engineering Radiology and Organ Imaging Neurosciences not elsewhere classified Animal Structure and Function Magnetic Resonance Imaging Gastrointestinal Physiology Rat Image Processing Vagus Nerve Stimulation
3	Hemodynamic and Geometric Changes of the Female Reproductive System in Health and Disease Jessica L Ma (8799200) 05 May 2020 (has links) <p>Preterm birth is the leading cause of newborn mortality, with 15 million babies born premature worldwide every year. Children that do survive early delivery are more likely to develop cognitive abnormalities, motor deficits, heart disease, cerebral palsy, and more. While little is known about the pathophysiology of preterm birth, several pregnancy-related complications are related to preterm birth, namely cervical insufficiency and preeclampsia. In the former, premature cervical remodeling and softening can result in the shortening of the cervix, increasing a woman’s risk of preterm birth; this condition is called cervical insufficiency (CI), which is the inability of the cervix to remain closed as a result of weakened tissues. CI is currently measured by a one-dimensional sonographic cervical length, where < 25 mm indicates shortening. Preeclampsia is a disorder that can be explained through the Page kidney phenomenon: compression of the left renal vein (LRV) causes renal venous outflow obstruction, leading to elevated intrarenal pressure and hypertension. The supine pressor test (SPT) is a diagnostic tool for preeclampsia where a positive test is defined by an increase of 20 mmHg in diastolic blood pressure (BP) when shifting from the left lateral recumbent to the supine position. Due to the intense risk of morbidity and mortality for both the mother and the fetus, the need to monitor BP changes is critical. Currently, there is an unmet clinical need to characterize the hemodynamic and geometric properties of the female reproductive organs throughout gestation. Utilizing ultrasound imaging can increase our knowledge about the 3D anatomy and systemic changes during pregnancy, unravel risk factors, establish preventative methods, and standardize treatment plans. In this thesis research, we developed a murine model to 1) examine the pathophysiology of renal vein stenosis, and 2) investigate the effects of stenosis on various cervical dimensions. Renal vein stenosis was found to greatly impact blood flow velocities, as well as cervical width (<i>p<0.05</i>). LRV and cervical area and height also trend towards significance, and there is negative damage to the left kidney and placentae within the stenosed cohort. We also conducted a human study that showed reduced change in postural BP in patients with higher body mass index (BMI). Systolic and diastolic BP in the supine position was significantly greater than in the lateral position for all BMIs with a baseline increase in BP of approximately 9-14 mmHg. These findings suggest that therapeutic positioning and close monitoring of BP could mitigate the risk of developing related disorders in pregnancy.</p> Physiology Health Care Foetal Development and Medicine Obstetrics and Gynaecology Community Child Health Health and Community Services Medical Devices Animal Physiology - Systems Animal Structure and Function pregnancy preeclampsia blood pressure medical devices diagnostic technology ultrasound imaging
4	<b>CHARACTERIZATION OF SERPINA1 IN ADULT SPINAL HOMEOSTASIS TO INFORM TREATMENT STRATEGIES</b> Neharika Bhadouria (17266174) 07 December 2023 (has links) <p dir="ltr">People suffering from COPD are also known to suffer from other musculoskeletal issues like fracture risk, back pain, etc. Intervertebral disc degeneration (IVD) is a prominent cause of back pain and inflammation, influenced by factors such as aging, sudden loading, and genetics. <i>SERPINA1</i>, a common genetic variant in individuals with chronic obstructive pulmonary disease (COPD), encodes the alpha-antitrypsin protein (AAT). AAT deficiency is also associated with IVD degeneration, bone loss, and gait impairment. Currently, AAT-deficient individuals receive costly and short-lived weekly AAT injections, with no established guidelines for managing IVD degeneration and osteoporosis. Our primary research objective was to examine the effects of <i>serpinA1a/c</i> using a mouse model with global knockout (KO) of <i>serpinA1a/c</i>, generated through CRISPR technology, on intervertebral discs (IVD) and bone. We found that global deletion of <i>serpinA1a/c</i> was found to cause IVD elastin degradation, leading to a loss of mechanical properties. Moreover, <i>serpinA1</i> was associated with increased bone-resorbing cells (osteoclasts) and a reduction in bone-forming cells (osteoblasts). Notably, sexual dimorphism was observed, with female IVDs exhibiting less degeneration than male counterparts, and <i>serpinA1a/c</i> KO mice were protected from mechanically-induced tail compression. Even in human IVDs, males expressed more AAT-1 compared to female IVDs. There are no FDA-approved drugs currently existing for IVD degeneration. Since IVD degeneration frequently occurs in individuals with osteoporosis, it shows a probable cross-talk happening between IVD and bone. In our study, we found the association of <i>serpinA1 </i>with estrogen receptor alpha and osteoclasts. Hence, we investigated the potential of raloxifene, an FDA-approved selective estrogen receptor modulator (SERM) typically prescribed to post-menopausal women for osteoporosis treatment, in averting IVD degeneration and improving mechanical characteristics in IVD. Our findings suggest that raloxifene injection may retard IVD degeneration induced by AAT deficiency, particularly in male mice. Furthermore, the latter study touched upon a conditional <i>serpinA1a</i> mouse model crossed with aggrecan-cre, specifically targeting <i>serpinA1a</i>-expressing cells in the IVD while sparing bone. Conditional <i>serpinA1a</i> deletion induced mild IVD degeneration without affecting bone loss. In summary, this study serves as a foundation for testing potential treatments for AAT patients with IVD degeneration and osteoporosis. It also provides compelling evidence for considering raloxifene as a treatment option for IVD degeneration in AAT-deficient patients experiencing IVD-related pain.</p> Genetically modified animals Animal structure and function Respiratory diseases Orthopaedics Pain Surgery Biomedical imaging Biomechanics SERPINA1 gene Raloxifene/pharmacokinetic Intervertebraldisc bone intervertebral disc injury Human intervertebral disc discogenic pain genetically modified animals Sex dimorphism aging behavioral assays Magnetic resonance Imaging Chronic obstructive pulmonary disease Spine biomechanics AAT-1 alpha-antitrypsin emphysema crosstalk treatment EVISTA tail disc lumbar disc tail compression FTIR QPCR Gene expression SerpinA1 isoforms lung conditional KO mice Global KO mice

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