Matching Items (10)

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Anthropomorphic Animated Animals

Description

Anthropomorphic animal characters are common in animation, but there is limited data on the factors that contribute to such a trend. I studied how animated animals in popular movies look

Anthropomorphic animal characters are common in animation, but there is limited data on the factors that contribute to such a trend. I studied how animated animals in popular movies look and behave like humans, and what that indicates about us that we prefer them that way. My study was conducted via literature review, film review, facial measurements, and the creation of my own character. I discovered the physical importance of eyes in proportion to the rest of the face and the emotional importance of those animals acting as metaphors for us as humans.

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Date Created
  • 2016-12

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The Relationship Between Vertebral Osteology and Microhabitat and Prey-capture Methods in Snakes

Description

Vertebral osteology varies greatly among snake species. This variation may be related to specialization in microhabitat and prey-capture. Radiographs of eight preserved male specimens were taken in order to analyze

Vertebral osteology varies greatly among snake species. This variation may be related to specialization in microhabitat and prey-capture. Radiographs of eight preserved male specimens were taken in order to analyze the vertebral length and morphology of snakes which exhibit extreme characteristics in microhabitat utilization and prey-capture methods (highly arboreal, effective constrictor). This group includes two representatives each from four major families within Serpentes: Boidae, Pythonidae, Viperidae, and Colubridae. The four boids and pythons are effective constrictors, while the four vipers and colubrids are non-constricting. One specimen of each pair is highly arboreal, while the other is terrestrial. Findings support previous research in that constrictors had larger total numbers of vertebrae than non-constrictors. When average maximum adult length and morphology of axial musculature was taken into consideration, however, flexibility gained by vertebral number alone does not theoretically confer a mechanical advantage during constriction, at least among the specimens examined. All arboreal specimens had tails with a greater number of vertebrae than their con-familial terrestrial counterpart, implicating greater flexibility in the caudal region as an important characteristic for arboreality across taxa. Examination of segments of 10 vertebrae revealed that the greatest vertebral elongation occurred at the midpoint of the thoracic region. Reduction in size and length of tail vertebrae appears to occur independently of thoracic vertebrae. Colubrids, specifically, demonstrated a unique caudal vertebral elongation pattern which could potentially be advantageous for quick locomotion. These results indicate that caudal morphology may be more important in behavioral specialization than previously thought.

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Date Created
  • 2016-12

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Chemoreception in Octopus bimaculoides

Description

Chemoreception is an important method for an octopus to sense and react to its surroundings. However, the density of chemoreceptors within different areas of the skin of the octopus arm

Chemoreception is an important method for an octopus to sense and react to its surroundings. However, the density of chemoreceptors within different areas of the skin of the octopus arm is poorly documented. In order to assess the relative sensitivity of various regions and the degree to which chemoreception is locally controlled, octopus arms were amputated and exposed to acetic acid, a noxious chemical stimulus that has previously been shown to elicit movement responses in amputated arms (Hague et al., 2013). To test this, 11 wild-caught Octopus bimaculoides (6 females, 5 males) were obtained. Acetic acid vapor was introduced in the distal oral, distal aboral, proximal oral, and proximal aboral regions of amputated arms. The frequency of the occurrence of movement was first analyzed. For those trials in which movement occurred, the latency (delay between the stimulus and the onset of movement) and the duration of movement were analyzed. The distal aboral and distal oral regions were both more likely to move than either the proximal oral or proximal aboral regions (p < 0.0001), and when they did move, were more likely to move for longer periods of time (p < 0.05). In addition, the proximal oral region was more likely to exhibit a delay in the onset of movement compared to the distal oral or distal aboral regions (p < 0.0001). These findings provide evidence that the distal arm is most sensitive to noxious chemical stimuli. However, there were no significant differences between the distal oral and distal aboral regions, or between the proximal oral and proximal aboral regions. This suggests that there may not be a significant difference in the density of chemoreceptors in the aboral versus oral regions of the arm, contrary to claims in the literature. The other independent variables analyzed, including sex, body mass, arm length, anterior versus posterior arm identity, and left versus right arm identity, did not have a significant effect on any of the three dependent variables analyzed. Further analysis of the relative density of chemoreceptors in different regions of the octopus arm is merited.

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Date Created
  • 2020-05

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Statistical Analyses of Octopus bimaculoides Morphology and Physiology

Description

Chapter 1: Functional Specialization and Arm Length in Octopus bimaculoides<br/>Although studies are limited, there is some evidence that octopuses use their arms for specialized functions. For example, in Octopus maya

Chapter 1: Functional Specialization and Arm Length in Octopus bimaculoides<br/>Although studies are limited, there is some evidence that octopuses use their arms for specialized functions. For example, in Octopus maya and O. vulgaris, the anterior arms are utilized more frequently for grasping and exploring (Lee, 1992; Byrne et al., 2006a), while posterior arms are more frequently utilized for crawling in O. vulgaris (Levy et al., 2015). In addition, O. vulgaris uses favored arms when retrieving food and making contact with a T-maze as dictated by their lateralized vision (Byrne, 2006b). O. vulgaris also demonstrates a preference for anterior arms when retrieving food from a Y-maze (Gutnick et. al. 2020). In Octopus bimaculoides bending and elongation were more frequent in anterior arms than posterior arms during reaching and grasping tasks, and right arms displayed deformation more frequently than left arms, with the exception of the hectocotylus (R3) in males (Kennedy et. al. 2020). Given these observed functional differences, the goal of this study was to determine if morphological differences exist between different octopus arm identities, coded as L1-L4 and R1-R4. In particular, the relationship between arm length and arm identity was analyzed statistically. The dataset included 111 intact arms from 22 wild-caught specimens of O. bimaculoides (11 male and 11 female). Simple linear regressions and an analysis of covariance were performed to test the relationship between arm length and a number of factors, including body mass, sex, anterior versus posterior location, and left versus the right side. Mass had a significant linear relationship with arm length and a one-way ANOVA demonstrated that arm identity is significantly correlated with arm length. Moreover, an analysis of covariance demonstrated that independent of mass, arm identity has a significant linear relationship with arm length. Despite an overall appearance of bilateral symmetry, arms of different identities do not have statistically equivalent lengths in O. bimaculoides. Furthermore, differences in arm length do not appear to be related to sex, anterior versus posterior location, or left or right side. These results call into question the existing practice of treating all arms as equivalent by either using a single-arm measurement as representative of all eight or calculating an average length and suggest that morphological analyses of specific arm identities may be more informative.<br/><br/>Chapter 2: Predicting and Analyzing Octopus bimaculoides Sensitivity to Global Anesthetic<br/>Although global anesthetic is widely used in human and veterinary medicine the mechanism and impact of global anesthetic is relatively poorly comprehended, even in well-studied mammalian models. Invertebrate anesthetic is even less understood. In order to evaluate factors that impact anesthetic effectiveness analyses were conducted on 22 wild-caught specimens of Octopus bimaculoides during 72 anesthetic events.Three machine learning models: regression tree, random forest, and generalized additive model were utilized to make predictions of the concentration of anesthetic (percent ethanol by volume) from 11 features and to determine feature importance in making those predictions. The fit of each model was analyzed on three criteria: correlation coefficient, mean squared error, and relative error. Feature importance was determined in a model-specific manner. Predictions from the best performing model, random forest, have a .82 correlation coefficient with experimental values. Feature importance suggests that temperature on arrival and cohabitation factors strongly influence predictions for anesthesia concentration. This likely indicates the transportation process was incurring stress on the animals and that cohabitation was also stressful for the typically solitary O. bimaculoides. This long-term stress could lead to a decline in the animal’s well-being and a lower necessary ethanol concentration (Horvath et al., 2013). This analysis provides information to improve the care of octopus in laboratory settings and furthers the understanding of the effects of global anesthetic in invertebrates, particularly one with a distributed nervous system.

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Date Created
  • 2021-05

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The Functional Anatomy of the Hindlimb of the Ringtail (Bassariscus astutus)

Description

The ringtail (Bassariscus astutus), a member of the Procyonidae, is capable of 180 degrees of hindlimb reversal during headfirst descent down a vertical substrate. The goal of this study was

The ringtail (Bassariscus astutus), a member of the Procyonidae, is capable of 180 degrees of hindlimb reversal during headfirst descent down a vertical substrate. The goal of this study was to determine the presence or absence of myological adaptations related to hindlimb reversal in the ringtail. Data for B. astutus are presented, including muscle weights and muscle maps ascertained from the dissection of four hindlimbs. Data from the current study were compared to published accounts of other species capable of hindlimb reversal, including procyonids (raccoon, coati, kinkajou, olingo), a mustelid (marten), palm civet, mongoose, tree squirrel, common tree shrew, and slow loris. Muscle mass data from this study demonstrate that the hip adductors of scansorial mammals are significantly more robust than those of terrestrial mammals, indicating a myological adaptation for climbing, but not necessarily hindlimb reversal. Among hindlimb reversers, the majority exhibit one belly of m. sartorius, the presence of m. extensor digiti I longus, and a fibular origin for m. fibularis longus. These characteristics indicate an emphasis on hip extension, ankle plantarflexion, and pes inversion. However, these characteristics are more likely due to phylogeny than hindlimb reversal because of their presence in closely-related non-reversers. Additional data on families outside of Carnivora may help determine if these myological traits are indeed due to phylogeny. Other myological data, such as moment arms and cross sectional areas, may provide evidence of adaptations for hindlimb reversal.

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Date Created
  • 2014-05

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Comparative Osteology and Morphometrics of the Caudal Axial Skeleton in Anolis carolinensis and Anolis sagrei

Description

Anole lizards that inhabit the islands and mainland of the Caribbean basin have evolved morphological traits adapted to the microhabitat that they occupy. The anoles on these islands have been

Anole lizards that inhabit the islands and mainland of the Caribbean basin have evolved morphological traits adapted to the microhabitat that they occupy. The anoles on these islands have been characterized as "ecomorphs" or morphologically and behaviorally-adapted groups, including: crown-giant, trunk-crown, trunk, grass-bush, twig, and trunk-ground. Ecomorphs display morphological features that are specifically adapted to the habitat that the anole occupies. One key morphological difference is tail length. While the anoles Anolis carolinensis and A. sagrei have similar ratios of tail length versus snout-to-vent length (SVL), they occupy different microhabitats. Specifically, A. carolinensis inhabits trunk-crown habitats while A. sagrei is found in trunk-ground regions. In this study, I focused on analysis of the caudal vertebrae of these two species, to determine if the structure of the osteological elements reflected differences in microhabitat adaptation. Skeletal preparations reveal that A. carolinensis have 40 \u2014 46 caudal vertebrae, and A. sagrei have 38 \u2014 49 caudal vertebrae. Transverse processes are present in Ca1-8 in A. carolinensis whereas transverse processes in A. sagrei span from Ca1-42 vertebrae. Ca6\u201440 have autotomy planes in A. sagrei, whereas only Ca8\u201417 have autotomy planes in A. carolinensis. These findings indicate that A. carolinensis are limited in the ability to autotomize their tail compared to A. sagrei. A. carolinensis, living higher in the trees than A. sagrei, might incur a greater impairment of locomotor function if autotomized. There appears to be no differences between males and females of both species in respect to vertebrae lengths. Differences between A. carolinensis and A. sagrei in terms of vertebral length are found in Ca12-15, 29-30, 34, and 37. The finding indicates that almost all caudal vertebrae between A. carolinensis and A. sagrei have similar relative lengths, but seven vertebrae have statistically significant differences. The biological significance of the findings is not clear, but functional and myological studies may help elucidate the reason of the observed differences.

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Date Created
  • 2013-05

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The Market For Bodies: Investigating the Landscape of Nontransplant Anatomical Donation Organizations

Description

While there is extensive information available about organizations that receive donated organs for transplant, much less is known about those that accept tissue and whole bodies for medical education and

While there is extensive information available about organizations that receive donated organs for transplant, much less is known about those that accept tissue and whole bodies for medical education and research. Throughout the United States, nontransplant anatomical donation organizations exist within an ambiguous sector of the donation industry, unencumbered by federal regulations. Although these companies adhere to the Uniform Anatomical Gift Act, the lack of a single entity responsible for overseeing their operations has led to public skepticism and animosity among competing businesses. Legislation has the potential to legitimize the industry. For it to be successful, however, the intricacies of a complex market that deals directly with the movement of human remains and intangible issues of human integrity and morality, must be thoroughly understood.

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Date Created
  • 2015-05

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Transcriptomic Analysis of Tail Regeneration in the Lizard Anolis carolinensis Reveals Activation of Conserved Vertebrate Developmental and Repair Mechanisms

Description

Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including

Lizards, which are amniote vertebrates like humans, are able to lose and regenerate a functional tail. Understanding the molecular basis of this process would advance regenerative approaches in amniotes, including humans. We have carried out the first transcriptomic analysis of tail regeneration in a lizard, the green anole Anolis carolinensis, which revealed 326 differentially expressed genes activating multiple developmental and repair mechanisms. Specifically, genes involved in wound response, hormonal regulation, musculoskeletal development, and the Wnt and MAPK/FGF pathways were differentially expressed along the regenerating tail axis. Furthermore, we identified 2 microRNA precursor families, 22 unclassified non-coding RNAs, and 3 novel protein-coding genes significantly enriched in the regenerating tail. However, high levels of progenitor/stem cell markers were not observed in any region of the regenerating tail. Furthermore, we observed multiple tissue-type specific clusters of proliferating cells along the regenerating tail, not localized to the tail tip. These findings predict a different mechanism of regeneration in the lizard than the blastema model described in the salamander and the zebrafish, which are anamniote vertebrates. Thus, lizard tail regrowth involves the activation of conserved developmental and wound response pathways, which are potential targets for regenerative medical therapies.

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Date Created
  • 2014-08-20

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Internal Longitudinal and Transverse Muscles in Relation to Octopus Arm Function

Description

The entirely soft-tissue anatomy of the octopus arm provides the animal with a large amount of freedom of movement, while still allowing the specimen to support itself despite the lack

The entirely soft-tissue anatomy of the octopus arm provides the animal with a large amount of freedom of movement, while still allowing the specimen to support itself despite the lack of a skeletal system. This is made possible through the use of various muscle layers within the octopus arm, which act as muscular hydrostats. Magnetic Resonance imaging of the octopus arm was employed to view the muscle layers within the octopus arm and observe trends and differences in these layers at the proximal, middle, and distal portions of the arms. A total of 39 arms from 6 specimens were imaged to give 112 total imaged sections (38 proximal, 37 middle, 37 distal). Significant increases in both the internal longitudinal muscle layer and the nervous core were found between the proximal and middle, proximal and distal, and middle and distal sections of the arms. This could reflect selection for these structures distally in the octopus arm for predator or other noxious stimuli avoidance. A significant decrease in the transverse muscle layer was found in the middle and distal sections of the arms. This could reflect selection for elongation in the proximal portion of the octopus arm or could be the result of selection for the internal longitudinal muscle layer and nervous core distally. Previous studies on Octopus vulgaris showed a preference for using the proximal arms in the pushing movement of crawling and a preference for using the anterior arms in exploring behaviors (Levy et al., 2015 and Byrne et al., 2006). Differences between the anterior and posterior arms for the transverse muscle layer, internal longitudinal muscle layer, and the nervous core were insignificant, reflecting a lack of structure-function relationships. This could also be due to a low sample size. Differences between the left and right arms for the transverse muscle layer, internal longitudinal muscle layer, and the nervous core were insignificant, supporting previous evidence that left versus right eye and arm preferences in octopus are not population-wide, but individual. Some slight trends can be found for individual arms, but the sample size was too small to make definitive statements regarding differences among specific arms.

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Date Created
  • 2019-05

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Octopus Transverse and Internal Longitudinal Arm Muscles in Relation to Fetching Movements

Description

Octopus arms employ a complex three dimensional array of musculature, called a
muscular hydrostat, which allows for nearly infinite degrees of freedom of movement without
the structure of a skeletal

Octopus arms employ a complex three dimensional array of musculature, called a
muscular hydrostat, which allows for nearly infinite degrees of freedom of movement without
the structure of a skeletal system. This study employed Magnetic Resonance Imaging with a
Gadoteridol-based contrast agent to image the octopus arm and view the internal tissues. Muscle
layering was mapped and area was measured using AMIRA image processing and the trends in
these layers at the proximal, middle, and distal portions of the arms were analyzed. A total of 39
arms from 6 specimens were scanned to give 112 total imaged sections (38 proximal, 37 middle,
37 distal), from which to ascertain and study the possible differences in musculature. The
images revealed significant increases in the internal longitudinal muscle layer percentages
between the proximal and middle, proximal and distal, and middle and distal sections of the
arms. These structural differences are hypothesized to be used for rapid retraction of the distal
segment when encountering predators or noxious stimuli. In contrast, a significant decrease in
the transverse muscle layer was found when comparing the same sections. These structural
differences are hypothesized to be a result of bending behaviors during retraction. Additionally,
the internal longitudinal layer was separately studied orally, toward the sucker, and aborally,
away from the sucker. The significant differences in oral and aboral internal longitudinal
musculature in proximal, middle, and distal sections is hypothesized to support the pseudo-joint
functionality displayed in octopus fetching behaviors. The results indicate that individual
octopus arm morphology is more unique than previously thought and supports that internal
structural differences exist to support behavioral functionality.

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Created

Date Created
  • 2019-05