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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Simultaneous comparison of the microcirculation in the cheek pouch and mesocaecum of the hamster in response to cold

Brooks, Arthur Maurice January 1964 (has links)
Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / The physiological behavior of the microcirculation in a skinlike surface area (cheek pouch of hamster) is compared with that in a visceral area (mesocaecum) of the same species (golden hamster). A microelectrode test has been used to measure and compare the threshold sensitivity of vascular smooth muscle on arterioles and venules, the susceptibility of small blood vessels to platelet thromboembolism in response to graded electrical stimulation of the endothelial wall, and the tendency of the vessel to rupture resulting in mtcrohemorrhage as the voltage and duration are increased. At room temperature, no significant differences Here found between the reactivity in the cheek pouch and that in the mesocaecum. The effect of low temperature (15°C and 5°C) on the behavior of the microcirculation in the cheek pouch has been investigated during local cooling of a portion of the pouch, during cooling of the entire pouch and during cooling of the entire animal. At decreased temperatures, the blood vessels were significantly less fragile as shown by increased resistance to rhexis following electrical stimulation of the vessel wall with a microelectrode. The reactivity of arteriolar smooth muscle decreased as shown by an elevation in the threshold to direct electrical stimulation; but no significant change occurred in the sensitivity to venular smooth muscle. The threshold for thrombus formation was not clear-cut at lowered temperatures, but there appeared to be a tendency toward increased thresholds. Vasorhexis was decidedly increased with decrease in temperature. Hematocrits and hemoglobin levels were elevated from normal in cold adapted hamsters. Prothrombin times were unexpectedly decreased rather than increased as reported in the literature. Hamsters cold stressed for approximately two weeks at 7°C were also tested with respect to reactions of the microcirculation to electrical stimuli, and their responses were found to be similar to those with local and total body cooling. Blood velocities and volume flows in individual vessels of the microcirculation were measured at room temperature (2.5°C) and also at 15°C and 5°C. Velocities and volume flows were also measured in hamsters not subjected to cold stress but only under the effects of anesthesia. Blood velocities and blood volume flows decreased with decreasing temperature and no correlation was found between the size of vessels and the rate of volume flow. Cold acclimated hamsters had blood velocities and volume flow rates higher than those found in hamsters at room temperature. Sodium pentobarbital has an apparent slowing effect on blood velocity which approaches normal values as the hamster awakens from the anesthesia. The true effectiveness of the protection possible with the "dehydrating" agents ethylene glycol and glycerol, were not evident in these studies because of the toxic levels necessary for such protection. Nevertheless, glycerol was more efficacious than ethylene glycol in ameliorating the responses of the microcirculation to the sequelae of cold injury. The value of Eastern moccasin venom as an indicator of the integrity of the vessel walls by petechial formation is questioned. Lyophilized and crystallized venom at different concentrations was tested on the cheek pouch, and extremely variable results occurred. Data obtained at 15°C with the venom revealed inconsistent results and varying petechial counts and therefore the variability in petechial counts could not be ascribed to cold per se. Cinephotomicrographic recordings of the effects of cold and the "protection" of dehydrating agents have been made on 16mm Kodachrome film. In addition, split-field cinephotomicrography was used to make simultaneous records of the microcirculation of the cheek pouch and mesocaecum on the same picture frame. / 2031-01-01
2

Effect of hot-iron branding on the cheek or upper hind limb on cortisol levels, behaviour and production in feedlot calves

Grobler, Maria Jacoba 25 June 2013 (has links)
Hot-iron branding on the upper hind limb in beef feedlot calves is a usual part of the processing procedure at arrival in many feedlots in South Africa. However, cheek branding is becoming more popular in feedlots due to ease of restraint and better visibility of the brand mark. However, the welfare aspects of cheek branding compared to leg branding have not been investigated. By monitoring physiological and behavioural markers this study was conducted to determine potential stress-related differences between feedlot calves which are branded on the leg, those branded on the cheek and control (sham-branded) animals. Thirty weaned crossbred beef calves, recently arrived at a commercial feedlot, were habituated to handling in a crush for seven days and then randomly divided into three groups of ten. Group A was branded on the cheek, Group B on the hind leg and Group C was sham-branded with a room temperature iron. Group C was further divided into two groups (n = 5) that were either sham-branded on the cheek or on the leg. Blood was collected at 0, 30, 60, 90 and 120 minutes after branding for serum cortisol determination with a commercial radioimmunoassay kit. In addition, faeces were collected from all animals on the day after arrival, as well as at day seven, two and one prior to branding, on the day of branding and for seven consecutive days. Faecal glucocorticoid metabolite levels were determined using a group-specific enzyme immunoassay measuring 11,17-dioxoandrostanes (11,17-DOA). Other outcomes monitored included behavioural traits for seven days after branding, individual average daily weight gain (ADG), morbidity and mortality during the feedlot period and histopathological evaluation of the brand mark on the skin after slaughter. Faecal 11,17-DOA concentrations were higher the day after transport than the day after branding (P < 0.001) indicating higher circulating levels of cortisol during transport. Compared to pre-branding levels, serum cortisol was not significantly higher at 30 minutes after branding in all three groups but hormone levels dropped significantly at 60 minutes post-branding. Concentrations at 90 and 120 minutes were not significantly different from pre-branding concentrations in all three groups. The quantifiable rise seen between 60 and 90 minutes post-branding could have been due to the extended time (up to 2.5 hours) spent in the crush. There were no statistically significant differences in blood cortisol or faecal 11,17-DOA between the cheek, leg or sham branded groups at any time. Vocalization occurred more frequently at the time of branding in the cheek branded group than in either the leg branded (P = 0.030) or the control group (P < 0.001). There were also no significant differences in other behavioural indices between the three groups. Faint brand marks could be seen at the time of slaughter (74 days after branding) on five animals from the leg branded group. No cheek brands were visible. No scarring was seen on histopathological examination. No significant differences were seen in the ADG, and there were no morbidities or mortalities. In conclusion, using the methods described, there were no obvious differences in serum cortisol levels, faecal 11,17-DOA levels, behavioural indicators of pain or production outcomes between feedlot calves branded on the cheek, the leg, or sham branded. / Dissertation (MMedVet)--University of Pretoria, 2012. / Production Animal Studies / unrestricted
3

Avaliação quantitativa de força de bochechas em humanos

Berbert, Monalise Costa Batista January 2013 (has links)
Atualmente, a avaliação da tonicidade de bochechas é realizada de forma perceptual e dependente da experiência do avaliador. Por esse motivo, este trabalho propôs uma alternativa para diminuir a subjetividade da forma de avaliação atual da força das bochechas, a qual pode complementar o diagnóstico fonoaudiológico. Desenvolveu-se um protótipo constituído de uma célula de carga acoplada a uma haste, sistema de conversão, amplificação e transmissão do sinal elétrico. Um estudo inicial buscou avaliar a repetitividade e reprodutibilidade de medições realizadas em sujeitos normais e alterados quanto à força das bochechas. Num segundo estudo visou-se quantificar e analisar a performance de indivíduos com força adequada. Os valores de força no sexo masculino, tanto para força média quanto para força máxima, foram estatisticamente maiores do que os valores entre o sexo feminino. Cinco tipos de curva caracterizam o comportamento da bochecha durante o ensaio. O método de avaliação quantitativa da força das bochechas desenvolvido colaborou para a diminuição da subjetividade da avaliação e foi capaz de registrar a força exercida pelas bochechas. / Currently clinical evaluation of cheeks tone is performed at a perceptual level and depends on the evaluator's experience. Therefore, this study aimed to propose an alternative way of reducing the subjectivity in cheeks strength assessments, which can complement the speech therapist diagnosis. We developed a prototype consists of a load cell coupled to a handle, the conversion system, amplification, and the electrical signal transmission. An initial study was toanalyze of repeatability and reproducibility of measurements performed in normal and abnormal individuals regarding cheek strength. In a second study sought to quantify and analyze the performance of subjects with adequate strength. The force values in males, both for strength and for average maximum force were statistically higher than the values among females. Five types of curve characterize the behaviour of the cheek during the test. The method of quantitative assessment of the cheeks strength developed helped to reduce the subjectivity of the evaluation and it was able to record the force exerted by the cheeks.
4

Avaliação quantitativa de força de bochechas em humanos

Berbert, Monalise Costa Batista January 2013 (has links)
Atualmente, a avaliação da tonicidade de bochechas é realizada de forma perceptual e dependente da experiência do avaliador. Por esse motivo, este trabalho propôs uma alternativa para diminuir a subjetividade da forma de avaliação atual da força das bochechas, a qual pode complementar o diagnóstico fonoaudiológico. Desenvolveu-se um protótipo constituído de uma célula de carga acoplada a uma haste, sistema de conversão, amplificação e transmissão do sinal elétrico. Um estudo inicial buscou avaliar a repetitividade e reprodutibilidade de medições realizadas em sujeitos normais e alterados quanto à força das bochechas. Num segundo estudo visou-se quantificar e analisar a performance de indivíduos com força adequada. Os valores de força no sexo masculino, tanto para força média quanto para força máxima, foram estatisticamente maiores do que os valores entre o sexo feminino. Cinco tipos de curva caracterizam o comportamento da bochecha durante o ensaio. O método de avaliação quantitativa da força das bochechas desenvolvido colaborou para a diminuição da subjetividade da avaliação e foi capaz de registrar a força exercida pelas bochechas. / Currently clinical evaluation of cheeks tone is performed at a perceptual level and depends on the evaluator's experience. Therefore, this study aimed to propose an alternative way of reducing the subjectivity in cheeks strength assessments, which can complement the speech therapist diagnosis. We developed a prototype consists of a load cell coupled to a handle, the conversion system, amplification, and the electrical signal transmission. An initial study was toanalyze of repeatability and reproducibility of measurements performed in normal and abnormal individuals regarding cheek strength. In a second study sought to quantify and analyze the performance of subjects with adequate strength. The force values in males, both for strength and for average maximum force were statistically higher than the values among females. Five types of curve characterize the behaviour of the cheek during the test. The method of quantitative assessment of the cheeks strength developed helped to reduce the subjectivity of the evaluation and it was able to record the force exerted by the cheeks.
5

Avaliação quantitativa de força de bochechas em humanos

Berbert, Monalise Costa Batista January 2013 (has links)
Atualmente, a avaliação da tonicidade de bochechas é realizada de forma perceptual e dependente da experiência do avaliador. Por esse motivo, este trabalho propôs uma alternativa para diminuir a subjetividade da forma de avaliação atual da força das bochechas, a qual pode complementar o diagnóstico fonoaudiológico. Desenvolveu-se um protótipo constituído de uma célula de carga acoplada a uma haste, sistema de conversão, amplificação e transmissão do sinal elétrico. Um estudo inicial buscou avaliar a repetitividade e reprodutibilidade de medições realizadas em sujeitos normais e alterados quanto à força das bochechas. Num segundo estudo visou-se quantificar e analisar a performance de indivíduos com força adequada. Os valores de força no sexo masculino, tanto para força média quanto para força máxima, foram estatisticamente maiores do que os valores entre o sexo feminino. Cinco tipos de curva caracterizam o comportamento da bochecha durante o ensaio. O método de avaliação quantitativa da força das bochechas desenvolvido colaborou para a diminuição da subjetividade da avaliação e foi capaz de registrar a força exercida pelas bochechas. / Currently clinical evaluation of cheeks tone is performed at a perceptual level and depends on the evaluator's experience. Therefore, this study aimed to propose an alternative way of reducing the subjectivity in cheeks strength assessments, which can complement the speech therapist diagnosis. We developed a prototype consists of a load cell coupled to a handle, the conversion system, amplification, and the electrical signal transmission. An initial study was toanalyze of repeatability and reproducibility of measurements performed in normal and abnormal individuals regarding cheek strength. In a second study sought to quantify and analyze the performance of subjects with adequate strength. The force values in males, both for strength and for average maximum force were statistically higher than the values among females. Five types of curve characterize the behaviour of the cheek during the test. The method of quantitative assessment of the cheeks strength developed helped to reduce the subjectivity of the evaluation and it was able to record the force exerted by the cheeks.
6

Interaction Between Winter Dominance and Territory Defense in Male Pronghorn Antelope, Antilocapra Americana

Gunnels, Charles William, IV 01 May 1999 (has links)
In a territorial population of pronghorn from Antelope Island, UT, interaction between male dominance and territory defense was examined. High-ranking males were more likely to defend territories. Closely ranked animals engaged in more dominance interactions than distantly ranked individuals, and middle-ranked animals were involved in disproportionately more interactions than either high- or low-ranking animals. Large males possessed large horns and prongs as well as small cheek patches. Results from a factor analysis suggested that large males defended territories with a high density of sage. However, in this study, we did not observe pronghorn feed on sage during the territorial season. Though male pronghorn practiced resource defense polygyny, large, dominant males did not defend territories with a high density of green vegetation or green forbs. Large males appeared to defend territories with low visibility. In 1996, intruders entered areas that contained females throughout the territorial season. During the next year, highly visible, small territories received the most intrusions. Together, these observations suggest defense of tactical locations. Defending a tactical location may help females avoid harassment and males hide the presence of females. Different populations of pronghorn practice different mating systems. To understand this variation, we examined the behavior patterns/rates of individual territorial and bachelor males. The highest rates of activity and behavior patterns occurred in March/April and in September. Territorial males cheek rubbed at a higher rate than bachelors. Territorial males were more active and SPUD (sniff, paw, urinate, and defecate) marked at a higher rate than bachelor males in 1996. After the formation of a bachelor herd in 1997, bachelor males showed higher rates of male-male interactions than territorial males. Territorial males maintained the same activity and behavioral rates in the presence and absence of females. Dispersion pattern of scent marks was more clumped in the presence of females. These findings suggest cheek rubs function more as a space-claiming behavior while SPUD marking is more strongly associated with male-male interactions. Comparison to male behavior in nonterritorial populations indicates that the behavioral mechanisms are present in all populations to accommodate shifts in social systems.
7

Social Isolation and Cell Phone Use by College Students

Myers, Nichol Elise 01 June 2013 (has links) (PDF)
In our technologically ever-advancing world, cell phones can either help us remain socially connected or can contribute to social isolation by substituting for face-to-face contact. This study examines the levels of social isolation in terms of the state of loneliness and trait of shyness and their correlations with academic achievement in 206 community college and university students to examine the connection between social isolation, GPA and cell phone use in college students. Two instruments used in the collection of data were the Revised Cheek and Buss Shyness Scale (RCBS) and the DeJong Gierveld Loneliness Scale. Correlational analysis was used to examine the relationships between variables. Hypothesis 1 proposed a significant negative relationship between higher levels of cell phone use and academic achievement as measured by self-reported GPA. This was partially supported by the research findings. Hypothesis 2 proposed a significant negative relationship between shyness and higher levels of cell phone use. This was also partially supported by the research findings. Hypothesis 3 proposed a significant positive relationship between loneliness and higher levels of cell phone use. This was not supported by research findings. Implications for further research include examining non-college populations for greater generalization of results and examining additional personality traits.
8

Porovnání raka mramorovaného a raka pruhovaného: přímá interakce a kompetice o zdroje

MAN, Milan January 2019 (has links)
Biological invasions of non-native species are one of the most serious factors threatening global biodiversity. Their negative impacts are particularly evident in the case of freshwater ecosystems and native crayfish populations that live there. Generally, the higher dominance of non-native crayfish species over the native species is relatively well known, but the interactions between non-native crayfish species are significantly less investigated. Although their distribution is increasingly more important and it is obvious that non-native crayfish species will dominate in European waters. However, it is not yet clear which of these crayfish will be more successful. The aim of this diploma thesis was to create a literature review on the topic of interspecific interactions in crayfish with emphasis on native and non-native crayfish species occurring in Europe. The experimental part of the thesis was focused on the comparison of direct interactions and competition for shelter between the widespread spiny-cheek crayfish Faxonius limosus (Rafinesque, 1817) and the newly increasingly occurring marbled crayfish Procambarus virginalis Lyko, 2017. These species are becoming increasingly common in the European wild, but about their mutual direct interactions and competition is largely unknown. During agonistic interactions the marbled crayfish won in significantly more fights than the spiny-cheek crayfish in the absence as well as presence of the shelter. The marbled crayfish established a significantly greater dominance over the females of the spiny-cheek crayfish in the absence and in the presence of shelter, but not over the males. It is also important to say that the presence of the shelter reduces the number of fights and their total duration. There was no significant difference in dominance established by occupation of shelter between the marbled crayfish and the spiny-cheek crayfish. Still, thanks to its aggressiveness, marbled crayfish is able to compete with other non-native species or displace them from freshwater ecosystems.
9

Monitoring invazního raka pruhovaného v ÚN Lipno a evaluace jeho predace vybranými druhy ryb / Monitoring of invasive spiny-cheek crayfish in Lipno dam and the evaluation of its predation on chosen fish species.

SALON, František January 2015 (has links)
Astacologic survey took place in ÚN Lipno and was conducted in time from 2012 till 2013. For the actual mapping of the occurrence of spiny-cheek crayfish, the locations of total 17 places were detected. These monitoring areas were carried out in two ways for collecting the samples. The trapping of all individuals was achieved with special instruments, like pots or traps by hands or with the help of nets. For the caught specimens of spiny-cheek crayfish, which were determined by sex, the length of carapace was measured and as well if possible, the postorbital carapace length was taken. Throughout the whole monitoring, 228 individuals of spiny-cheek crayfish were caught in the amount of 107 (47%) females (CL = 21.5 ? 7.3 mm) and 121 (53%) males (CL = 20.1 ? 5 mm). Another aim of this work was to demonstrate that crayfish figure in fish food menu. Catches of fish were carried out in two ways, using fishing rods or into the clutches. The stomachs and intestines contents were analyzed at caught fish samples. If the condition of the contents of stomachs or intestines were allowed, it was also identified, what kind of food it was. For our annual issues, were included mainly species of piscivor fish. Spiny-cheek crayfish were identified in the stomachs of two species of fish, namely perch and pike.
10

Facial reconstruction according to aesthetic units

Nunez Castaneda, José, Chang Grozo, Silvana 01 October 2020 (has links)
Context: The facial subunit principle organizes the facial skin into subunits. Facial reconstruction for skin cancer based on aesthetic units consists of replacing the entire subunit when a large part of a subunit has been removed. Aims: To determine the prevalence of facial skin cancer, their location by facial aesthetic units, and the type of facial reconstruction used in each of them. Settings and Design: An observational cross-sectional study was conducted at the Head and Neck Surgery Service of a general hospital between 2017 and 2018. Materials and Methods: A population census was conducted during this period. Statistical Analysis Used: The categorical variables were expressed as frequencies (percentages). Continuous variables were described as the means and standard deviations or medians and interquartile ranges. Results: The most common skin cancer was basal cell skin cancer, followed by epithelial skin cancer and, at last, melanoma. In general, the most frequent localization of these cancers was the nose. Conclusions: In spite of primary closure being the most common form of reconstruction, a considerable number of patients required facial reconstruction based on aesthetic facial units, with satisfying results. / Revisión por pares

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