Microscopic Evaluations of Bone in Equine and Muroid Models

The use of advanced imaging techniques has greatly improved orthopedic research and education. Histology of bone is a method of evaluating bone morphology, bony cells, and bone remodeling in two-dimensions, while micro-computed tomography (microCT) is a three-dimensional analysis of bone morphology. Combined, these methods assist in providing a comprehensive analysis of bone. In this dissertation, these techniques were utilized to answer questions currently outstanding in veterinary medicine: the effect of bisphosphonates on equine bone, and variation in murine tarsal anatomy. Bisphosphonates are drugs that reduce osteoclast-mediated bone resorption and have recently been approved for the use in horses. Despite prolific clinical use, there has been little evidence of their effect on bone in horses. Therefore, the goal of these studies was to determine the impact of bisphosphonates on bone in normal, young horses. This was accomplished by evaluating bone biopsies taken before and 60 days after a single bisphosphonate administration. Biopsies were analyzed using microCT and histomorphometry. We found that the bisphosphonates studied have minimal to no effect on bone morphology and remodeling, and therefore conclude that these drugs do not negatively impact bone, and have no effect after 60 days. Mice are the most commonly utilized animal model for orthopedic research, and knowledge of normal anatomy is critical to identify pathologies secondary to disease. We found conflicting evidence regarding the tarsal anatomy in the mouse. While normal tarsal variation exists in other species, this has not been documented in the mouse. Therefore, the purpose of this study was to characterize the tarsal anatomy of the mouse. MicroCT data from muroid tarsi were collected, and representative tarsi were evaluated by histology. Fusion of the central and tarsal bone III was present in all laboratory mice evaluated, but was not present in the laboratory rat or wild white-footed mouse. This fusion was confirmed via histology; however, hyaline cartilage was present, surrounded by mature trabecular bone indicating a joint remnant despite the fused state of the bones. We conclude that in certain laboratory mouse strains, the central and tarsal bone III are fused into a single bone

Concept Mapping as a Tool for Enhancing Self-Paced Learning in a Distance Scenario

Researchers have determined that concept maps serve as effective tools in the traditional science classroom. The purpose of this experimental study was to investigate concept mapping as a tool for student knowledge acquisition in 10th grade science for students in distance learning situations. Research questions were designed to investigate the influence of concept mapping on rate and quality of student knowledge acquisition and retention. This study was a pretest-posttest 2-group comparison study, constructivist in nature and based on the theory of cognitive learning. Participants included 36 students in the 10th grade at an inner-city school in the United States. Control and treatment groups participated in completing pre and posttesting to establish standards for initial understanding and knowledge acquired. Pretest scores were used in a 2-tailed t test to establish equivalence between groups at the beginning of the study. ANOVA was used with test gains to determine differences between treatment and control groups. Cronbach\u27s alpha was conducted to test for concept map interrater reliability. A 2-tailed t test for matched groups was used with concept map scores and treatment group test gains to determine any relationship. No statistically significant relationship between the use of concept maps and distance learning was found. Recommendations for future research include a wider age range for participants and investigations of academic areas such as reading, writing, mathematics, and language acquisition, native and foreign. Implications for positive social change include research with altered parameters to identify an existing tool that may be used by students in the traditional classroom as well as in distance-learning scenarios

St. Augustine in the Seventeenth-Century: Capital of La Florida

In 1600 St. Augustine was the only European settlement in today\u27s United States and the capital of Spain\u27s territory known as La Florida.1 The city was thirty-five years old as the sixteenth century blended into the seventeenth. Threats to St. Augustine\u27s survival began and ended the seventeenth century. The Spanish crown\u27s 1602 investigation about whether to retain St. Augustine began the century. A hundred years later the 1702 siege and burning by invaders from English Carolina ended the century. In between those events, St. Augustine endured decades of epidemics and the rise of piracy. The last third of the century saw an influx of money to build a strong fortress and more soldiers to protect the city and the La Florida colony as English settlements moved ever closer and into Spanish-claimed lands

Tiludronate and clodronate do not affect bone structure or remodeling kinetics over a 60 day randomized trial

Background Tiludronate and clodronate are FDA-approved bisphosphonate drug therapies for navicular disease in horses. Although clinical studies have determined their ability to reduce lameness associated with skeletal disorders in horses, data regarding the effect on bone structure and remodeling is lacking. Additionally, due to off-label use of these drugs in young performance horses, effects on bone in young horses need to be investigated. Therefore, the purpose of this randomized, experimental pilot study was to determine the effect of tiludronate and clodronate on normal bone cells, structure and remodeling after 60 days in clinically normal, young horses. Additionally, the effect of clodronate on bone healing 60 days after an induced defect was investigated. Results All horses tolerated surgery well, with no post-surgery lameness and all acquired biopsies being adequate for analyses. Overall, tiludronate and clodronate did not significantly alter any bone structure or remodeling parameters, as evaluated by microCT and dynamic histomorphometry. Tiludronate did not extensively impact bone formation or resorption parameters as evaluated by static histomorphometry. Similarly, clodronate did not affect bone formation or resorption after 60 days. Sixty days post-defect, healing was minimally affected by clodronate. Conclusions Tiludronate and clodronate do not appear to significantly impact bone tissue on a structural or cellular level using standard dose and administration schedules

Kinematic Analysis of Prey Capture in Coastal Giant Salamanders (Dicamptodon tenebrosus)

Salamanders use a variety of techniques to capture prey that involves a combination of lingual and jaw prehension. For example, some plethodontid salamanders often use ballistic tongue projection to capture prey. Salamanders of the family Dicamptodontidae, are the largest sized terrestrial salamanders in the world which feed on a diverse array of prey items (arthropods, annelids, small mammals, and reptiles). Objectives of our study were to describe and quantify the behavior of terrestrial adult coastal giant salamanders (D. tenebrosus). While there has been much research conducted on aquatic phase D. tenebrosus, little is known about their terrestrial counterparts. Feeding bouts of three distinct prey types (e.g., crickets, earthworms, and slugs) were recorded using high-speed video (420-1000 frames/second) recorded with a Casio Exlim EX-ZR100 digital camera. For a feeding trial, salamanders were offered a prey item with forceps. Trials were repeated on separated days with each salamander (N=12) being exposed to equal ratios of prey items. Videos were analyzed for velocity of initial strike, lingual projection, lower and upper jaw prehension, and feeding success. Non-metric multi-dimensional scaling analysis indicated significant differences in feeding patterns among prey types. Lingual prehension was the prominent method of ingestion when a small prey item was offered (crickets) and the use of upper and lower mandible were used in a snapping motion with larger prey items (earthworms). Future work will incorporate different prey items, as well as examine prey preference and foraging behaviors of D. tenebrosus. Additionally some comparative analysis will be conducted using the tiger salamander (Abystoma tigrinum) and the tailed frog (Ascaphus truei) on the mechanics of prey capture in amphibian taxa

Prevalence of MRSA and Antimicrobial Resistance of Staphylococcus aureus in Maryland Ground Meat Products

Gemstone Team Antibiotic ResistanceThe aim of this study was to evaluate the risk of exposure to antimicrobial-resistant Staphylococcus aureus from food-grade raw ground meat products in Maryland. Samples of ground beef (n = 198), pork (n = 300), and turkey (n = 196), were collected by random sampling from March-August, 2008. All isolates were tested for resistance to methicillin and confirmed S. aureus isolates (n = 200) were tested for susceptibility to 21 additional antimicrobials. Overall, turkey- and pork-derived isolates were more likely to be resistant to commonly used antimicrobials. One isolate from pork was confirmed to be the USA100 strain of MRSA and was resistant to 10 antibiotics. In addition, antibiotic-resistant non-S. aureus isolates were characterized and may represent a source for the transfer of resistance genes to S. aureus. Our findings suggest that meat production practices may impact the prevalence and antimicrobial resistance of S. aureus in ground meat

MusMorph, a database of standardized mouse morphology data for morphometric meta-analyses

Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N = 10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase (www.facebase.org, https://doi.org/10.25550/3-HXMC) and GitHub (https://github.com/jaydevine/MusMorph)

MusMorph, a database of standardized mouse morphology data for morphometric meta-analyses.

Complex morphological traits are the product of many genes with transient or lasting developmental effects that interact in anatomical context. Mouse models are a key resource for disentangling such effects, because they offer myriad tools for manipulating the genome in a controlled environment. Unfortunately, phenotypic data are often obtained using laboratory-specific protocols, resulting in self-contained datasets that are difficult to relate to one another for larger scale analyses. To enable meta-analyses of morphological variation, particularly in the craniofacial complex and brain, we created MusMorph, a database of standardized mouse morphology data spanning numerous genotypes and developmental stages, including E10.5, E11.5, E14.5, E15.5, E18.5, and adulthood. To standardize data collection, we implemented an atlas-based phenotyping pipeline that combines techniques from image registration, deep learning, and morphometrics. Alongside stage-specific atlases, we provide aligned micro-computed tomography images, dense anatomical landmarks, and segmentations (if available) for each specimen (N = 10,056). Our workflow is open-source to encourage transparency and reproducible data collection. The MusMorph data and scripts are available on FaceBase ( www.facebase.org , https://doi.org/10.25550/3-HXMC ) and GitHub ( https://github.com/jaydevine/MusMorph )