The elasmobranch fishes possess a remarkable diversity of feeding mechanisms for a group containing relatively few species (~1200). The three most prevalent of these mechanisms involve prey capture during which the predator overtakes its prey (ram), prey is drawn into the mouth of the predator (suction), and relatively stationary consumption of sessile or substrate affixed prey (biting). Biomechanical modeling of cranial force distributions, in situ bite performance trials, and kinematic analysis of prey capture behaviors were employed to identify morphological and behavioral specializations and constraints associated with these feeding mechanisms in lemon Negaprion brevirostris (ram), whitespotted bamboo Chiloscyllium plagiosum (suction), and horn Heterodontus francisci (biting) sharks. Biomechanical modeling of the forces generated by the cranial musculature was used to theoretically estimate the maximum bite force and mechanical loadings occurring throughout the hyostyl ic jaw suspension mechanisms of each species, characterized by suspensory hyomandibular cartilages between the back of the jaws and cranium and anterior ligamentous attachments. To assess the mechanical factors involved in the evolution of elasmobranch jaw suspension mechanisms, the feeding mechanism of the sharpnose sevengill shark Heptranchias perlo was modeled as well. Heptranchias perlo possesses an ancestral amphistylic jaw suspension mechanism including non-suspensory hyomandibular cartilages, a large post-orbital articulation between the jaws and cranium, and anterior ligamentous attachments. Theoretical estimates of maximum bite force were compared to voluntary bite forces measured during in situ bite performance trials. Voluntary bite force measurements allowed the quantification of discrete behavioral attributes of bite force application in each species. To further assess the behavioral specializations associated with these feeding mechanisms, high-speed digital videography w as used to analyze the prey capture cranial kinematics of species. Collectively, these analyses have developed a morphological and behavioral basis from which to understand the functional diversity of the ram, suction, and biting feeding mechanisms in elasmobranchs.

The mental and physical benefits of pet ownership are well established; however, pets can also transmit pathogens to people, with children, elderly, pregnant and immunocompromised individuals at greatest risk of disease. Little is known about the public’s knowledge and practices related to pet-associated disease. Questionnaires were distributed at two general practice physician clinics and to parents/guardians of children diagnosed with diabetes or cancer at specialty practice clinics. Pet ownership and contact were common, with 64-66% of participants having a pet in their household. Acquisition of a new pet, including high-risk pets, was common (20%) following a diagnosis of cancer in children. Pet exposure outside the home was frequently reported for individuals in pet and non-pet owning households (25-52%). Education of respondents about diseases was poor, as only approximately one-third recalled receiving pet-associated disease information. Parents of cancer patients were more likely than parents of diabetes patients to recall receiving this information, yet proportions were low in both groups (32% and 13%, respectively). Respondents’ knowledge of pet-associated pathogens was similar between the groups, with pet owners and parents of diabetic children having higher knowledge. Pet (30-36%) and non-pet (~10%) owning households reported dog/cat bites or scratches during the preceding year. Within the general practice respondents, lower-risk households did not differ from higher-risk households regarding perceived disease risk of pets, zoonotic disease knowledge, recall of being asked by their medical provider if they owned pets, or recall of having received information regarding pet-associated disease risks and preventive measures. Pet ownership, husbandry and infection control practices were similar between low- and high-risk households. Husbandry practices that increase zoonotic disease risk were frequently identified, including feeding high-risk diets, allowing children to clean up fecal material and allowing reptiles to roam through the kitchen. With few exceptions, practices were not associated with the presence of higher-risk members in the household or recall of having previously received zoonotic disease education. There is a need for improved education on zoonotic disease prevention practices for pet- and non pet-owning households, particularly those with individuals at higher risk of infection and those with high-risk species.

Thesis (M.S.)--University of Michigan, 1976.

Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.S.)--University of Michigan, 1976.

Thesis (M.S.)--University of Michigan, 1978.

Thesis (M.S.)--University of Michigan, 1989.

Thesis (M.S.)--University of Michigan, 1973.

Thesis (M.S.)--University of Michigan, 1981.

O sistema estomatognático constitui entidade fisiológica e funcional integrada por um conjunto de órgãos e tecidos, cuja biologia e fisiopatologia são absolutamente interdependentes. A perda dental determina importantes alterações no sistema estomatognático, as quais afetam, particularmente, o osso, a mucosa bucal e a função muscular. A performance mastigatória deteriora com a perda dos dentes, pois esta depende das condições da dentição, que inclui o número de dentes presentes em oclusão funcional, o número de dentes posteriores em contato, as áreas funcionais de contato e o grau de maloclusão. Para que haja a reabilitação funcional do sistema estomatognático e, consequentemente, da função mastigatória em indivíduos com perdas dentais parciais e/ou totais, fatores importantes devem ser considerados, como a reabilitação protética e muscular. Considerando, ainda, ser relevante a influência da musculatura na reabilitação funcional do sistema estomatognático, é importante, avaliar o comportamento da musculatura mastigatória frente às diferentes reabilitações protéticas. Este estudo tem como objetivo analisar a atividade eletromiográfica, a espessura dos músculos masseter e temporal, a força de mordida e a eficiência mastigatória de indivíduos adultos reabilitados com diferentes tipos de prótese dental, e com isso traçar um padrão de comportamento muscular de acordo com os diferentes tipos de reabilitação. Os resultados deste trabalho permitem a avaliação integral do sistema estomatognático do ponto de vista morfológico e funcional. Os aspectos investigados objetivam facilitar diagnósticos e prognósticos, trazendo contribuições para a comprovação da qualidade e estabilidade dos tratamentos. / The stomatognathic system is a physiological and functional entity comprising a set of organs and tissues, whose biology and pathophysiology are absolutely interdependent. The tooth loss causes important changes in the masticatory system which affects bone, oral mucosa and muscle function. The masticatory performance deteriorates with tooth loss because it depends on the dentition, which includes the number of teeth present in functional occlusion, the number of posterior teeth in contact, the size of the functional areas of contact and degree of malocclusion. In order to have the rehabilitation of the stomatognathic system and consequently the masticatory function in patients with partial and / or complete tooth loss, important factors should be considered as muscle and prosthetic rehabilitation. Considering relevant the influence of the muscles in the rehabilitation of the stomatognathic system, the intention of this work was to evaluate the behavior of the masticatory muscles in different prosthetic rehabilitation. This study aims to analyze the electromyographic activity, the thickness of the masseter and temporal muscles, bite force and masticatory efficiency of adult individuals rehabilitated with different types of dental prosthesis, aiming to draw a pattern of muscle according to the different types of rehabilitation. These results allow full assessment of the stomatognathic system in terms of morphological and functional. The study focused aim to facilitate diagnosis and prognosis, bringing contributions to the quality and stability of treatments.