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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

Geometric Morphometric Analysis of Third Instar Larvae of Common Blow Fly (Diptera: Calliphoridae) Genera for Forensic Identification

Gregory Nigoghosian (6984845) 15 August 2019 (has links)
<p>In terms of forensic entomology, one area that is scrutinized most is the estimation of a minimum post mortem interval (mPMI) based on insects that are present at a crime scene. The identification of the insects found at the scene if the first step to calculate a mPMI. However, currently there are no methods that can present the courts with accurate statistical error rates in identification, because the current methods are reliant on an expert’s use of a morphological key to identify the specimen, and this identification method does not produce a confidence value. This project aimed to test a method of identification using geometric morphometrics that can produce confidence intervals to provide to the courtrooms. </p><p> Before any identification could start, a standard preservation protocol was developed to ensure that all diagnostic features are preserved, and specimens can be identified in the same way. A clearing method was designed to clear specimens within 24hrs using potassium hydroxide, so they can be dissected and mounted the next day. The dissection of the specimens was a simple six-step procedure to split the mouth hooks, the cuticle and the posterior spiracle. This procedure ensures that all diagnostic features are preserved on a microscope slide.</p><p> With all of the features preserved, the microscope slide is photographed for storage and an investigator can perform geometric morphometrics to identify the insect. This study tested the application of geometric morphometrics to distinguish between three genera of Calliphoridae (<i>Calliphora</i>,<i>Lucilia</i>, <i>Phormia</i>), from three locations in the US (Delaware, Indiana, California). Results showed significant (p-value: <0.05) variation in shape among all genera. When genera were tested for shape differences based on location, these variations were also significant (p-value: <0.05). The implication of these results is that enough shape difference exists to distinguish between these genera and to distinguish between populations.</p>
2

Advanced Studies in Veterinary Anatomy: Angiogenesis in Caprine Reproductive Organs of Non-Pregnant and Pregnant Normal and Swainsonine-Treated Does

Hafez, Shireen Abdelgawad 22 April 2005 (has links)
The female reproductive organs are among the few adult tissues in which periodic angiogenesis normally occurs. Pathological angiogenesis can occur in various conditions, such as solid tumors. Vascular endothelial growth factor (VEGF) signaling often represents a critical rate-limiting step in physiological and pathological angiogenesis. This study utilizes development of utero-ovarian vasculature during pregnancy in goats as a model of physiological angiogenesis. Non-pregnant does and does at 4, 7, 10, 13, 16, and 18 weeks of gestation were used. Arteries of the reproductive tract were injected <i>in situ</i> with Microfil®. The tracts were fixed, dehydrated, and rendered transparent to reveal the paths of arteries. The ovarian artery was tortuous and lay in close apposition to the uterine tributary of the ovarian vein in all specimens studied. In non-pregnant does, this arrangement may serve as a local utero-ovarian pathway for the corpus luteum (CL) luteolysis at the end of non-fertile estrous cycle. During pregnancy, this arterio-venous arrangement may transfer luteotropic substances from uterus to ovary, which may serve in maternal recognition of pregnancy and fit the fact that the goat is CL dependent throughout gestation. In some cases of triplets, the size of the uterine branch of the ovarian artery was equal to or even larger than that of its parent artery and/or the ipsilateral uterine artery; and the vaginal artery contributed a connecting branch to the uterine artery. These physiological adaptations of the ovarian and/or vaginal arteries correlate well with the increasing nutrient demands of the growing multiple fetuses. In a second experiment, the vasculature of the uterus and ovaries was injected <i>in situ</i> with a mixture of Batson's No.17® and methyl methacrylate and then processed for observation by SEM. The microvasculature differed between non-pregnant and pregnant does, and with advancing gestation. We concluded that goats possess a <i>multivillous</i> type placenta. Capillary sinusoids and crypts on the fetal surface of the caruncle may compensate for the negative effect of the increased interhemal distance. Intussusceptive angiogenesis should be considered as equally possible and important mechanism as sprouting angiogenesis during placental development. Capillary diameters increased significantly during pregnancy especially after 4 weeks. Capillary density index was 66.8, 68.7, 55.5, 63.5, 70.1, 70.4, 64.5 percent in non-pregnant, 4, 7, 10, 13, 16, and 18 weeks of pregnancy, respectively. In the ovary, coiling of the ovarian branch of the ovarian artery around the ovarian tributary of the ovarian vein was observed. This may represent a local channel required for product transport from ovarian vein to ovarian artery and might have a role in regulating blood pressure to various ovarian structures. Immunolocalization of VEGF was performed as a third experiment. Immunostaining was observed in cyto- trophoblasts, maternal epithelial tissues, and vascular endothelium and smooth muscle, but not in binucleate giant cells or connective tissue. No apparent differences were observed in intensity and pattern of VEGF staining associated with advancing gestation. Luteal and follicular cells, and endothelium and smooth muscles of the ovarian vasculature positively stained. Patterns and intensity of staining of VEGF suggest that the fetus is directing its own survival by producing growth factors affecting fetal and maternal tissues. VEGF may have a role in growth and differentiation of cytotrophoblasts, as well as, development and maintenance of CL. In the fourth experiment, the sequential expression of VEGF and its receptors (fms-like tyrosine kinase, Flt-1 and kinase-insert domain-containing receptor, KDR) was measured using real-time quantitative PCR. Targets were detected in all studied tissues; however, levels of expression differed according to the stage of pregnancy. Expression of VEGF and its receptor mRNAs increased with advancing pregnancy, which correlates with the expansion of vasculature during pregnancy. Differences in the time-courses of the expression of Flt-1 and KDR mRNAs during pregnancy suggest that each receptor plays a different role in the angiogenic process. As an application of our model of angiogenesis, we tested the effect of swainsonine (active compound of locoweed and a potential anti-cancer drug) on the process. Does treated with swainsonine were euthanized at 7 and 18 weeks. No significant differences were found in sinusoidal diameters in treated does at 7 weeks, but a decrease in capillary density index was noted. In the ovary, focal avascular areas were observed in the corpus luteum of swainsonine-treated does at 7 weeks of pregnancy. Swainsonine caused great distortion in the uterine and ovarian vasculature at 18 weeks. A decrease in intensity of the immunoreactivity to VEGF antibody was observed in tissues from swainsonine-treated does at 7 and 18 weeks. There was no substantial effect of swainsonine on the expression of VEGF and its receptors' mRNAs in any of the studied tissues (except in the left ovary, where it had an inhibitory effect) at 7 weeks of pregnancy, but it had an inhibitory effect at 18 weeks. Demonstration of swainsonine's potential to negatively affect vascular development and suppress genes likely involved in angiogenesis at critical stages of blood vessel proliferation lends credibility to its potential as anti-cancer drug. / Ph. D.
3

Análise do preparo de canais radiculares realizado pelos alunos do curso de Odontologia da UFES utilizando-se a diafanização

Martin, Georje de 12 July 2013 (has links)
Made available in DSpace on 2016-12-23T13:54:30Z (GMT). No. of bitstreams: 1 Georje De Martin.pdf: 1822887 bytes, checksum: 44cf4db2a72f6678823eeb4f428a165a (MD5) Previous issue date: 2013-07-12 / The first contact of students with Endodontics Dentistry School of the Federal University of Espírito Santo is in the fifth period of the course in the Discipline of Endodontics I. In it, students know the Endodontics principles: morphology, coronary access, root canal preparation techniques, disinfection and obturation of the root canal system. Learning occurs in previously extracted teeth before the academics have any contact with the endodontic clinic at the Discipline of Endodontics II in the following period. The aim of this study was to analyze through the clearing technique the canals were prepared during this Discipline (laboratory). The quality of the preparation chemical-mechanical techniques was examined concern the shaping of the root canal and compared the best result of the same, visualized the anatomical features of the root canal system, compared the radiographic exam of the teeth and clearing technique and also checked whether the students have assimilated the knowledge of Endodontics. The data collected were subjected to Binomial test,Kappa and Chi-square test. These showed that: the modeling of root canals analyzed by the clearing technique, 67% were modeled with a statistical significance of 0.002 (p<0.05), as the comparison between the preparation chemical-mechanical techniques used in relation to the relative frequency the variable modeling of the root canals was 65.9% when modeled channels prepared with step-back technique and 68.2% of teeth modeled when prepared by Oregon Modified technique (p=0.8206) with no statistically significant difference between techniques, and as the concordance of the results of variable modeling of the root canals between the radiographic examination (73.8%) and clearing technique (67%) yielded a Kappa value=0.511 showing a moderate agreement between the two visualization techniques. It was concluded that: the modeling of channels was satisfactory showing that students are assimilating the knowledge of the Discipline; radiography proved to be limited in view of the channel modeling and also in view of the anatomical features of the root canal system, and also that the clearing technique is a visualization technique accessible and essential to the development of education in the Discipline of Endodontics / O primeiro contato dos acadêmicos do Curso de Odontologia da Universidade Federal do Espírito Santo com a Endodontia ocorre no quinto período do curso na Disciplina de Endodontia I. Nele, os acadêmicos conhecem os princípios que permeiam a Endodontia: morfologia, acesso coronário, técnicas de preparo, desinfecção e a obturação do sistema de canais radiculares. O aprendizado ocorre em dentes previamente extraídos e precede o contato dos acadêmicos com a clínica endodôntica na Disciplina de Endodontia II no período seguinte. O objetivo dessa pesquisa foi analisar através da técnica de diafanização, os canais radiculares preparados durante a Disciplina de Endodontia I (laboratorial). Nestes se analisaram a qualidade das técnicas de preparo químico-mecânico quanto a modelagem do canal radicular e comparativamente o melhor resultado das mesmas, visualizou-se as características anatômicas do sistema de canais radiculares, comparou-se o exame radiográfico e a diafanização dos dentes e também se verificou se os alunos assimilaram os conhecimentos da Endodontia. Os dados coletados foram submetidos ao teste Binomial, teste Kappa e ao teste Qui-quadrado. Estes demonstraram que: quanto a modelagem dos canais radiculares analisados pela técnica da diafanização, 67% foram modelados com significância estatística de 0,002 (p<0,05); quanto à comparação entre as técnicas de preparo químicomecânico utilizadas, a freqüência relativa em relação à variável modelagem dos canais foi de 65,9% de canais modelados quando preparados pela técnica Escalonada Regressiva e de 68,2% de dentes modelados quando preparados pela técnica de Oregon Modificada (p=0,8206) estatisticamente não havendo diferença entre as técnicas; e quanto à concordância dos resultados da variável modelagem do canal, entre o exame radiográfico (73,8%) e a técnica da diafanização (67%) obteve-se um valor Kappa=0,511 mostrando uma concordância moderada entre as duas técnicas de visualização. Concluiu-se que: a modelagem dos canais foi satisfatória mostrando que os alunos estão assimilando os conhecimentos da Disciplina; a radiografia revelou-se limitada na visualização da modelagem dos canais e na visualização das características anatômicas do sistema de canais radiculares; e que a diafanização é uma técnica de visualização acessível e imprescindível para a evolução do ensino na Disciplina de Endodontia

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