The Heron Lake Stock is a lenticular shaped, pretectonic granitoid complex intruding the Jutten metavolcanics of the Savant Lake Greenstone Belt, Wabigoon Subprovince, Superior Province. Mapping, petrography, and chemical analyses have revealed that the stock is essentially trondhjemitic, with minor quartz diorite, granodiorite and quartz monzonite. The trondhjemites have undergone a high degree of sericitization and saussuritization. The grandiorite unit is characterized by secondary K-feldspar and the quartz monzonites are characterized by perthite formation as a result of K-autometasomation is the late stage potash-rich fluids. Late faulting has imposed a secondary foliation along the stock's southern boundary. K/Rb ratios suggest partial melting of lower crust/ upper mantle material producing a trondhjemitic magma. Chemical variation diagrams suggest a process of magmatic differentiation and fractional crystallization. / Thesis / Bachelor of Science (BSc)

A phenomenon of large, upland breeding colonies of cattle egrets in residential areas of Central Texas has been observed since the early 1960s. These large concentrations of breeding birds can be a nuisance to nearby residents and their management has been difficult. To help understand why cattle egrets choose upland, residential breeding sites, and predict where these might occur, the geographic extent of the phenomenon was bounded within Texas, a habitat suitability model constructed, and reproductive success compared by breeding habitat type to evaluate if residential nesting confers an adaptive advantage.. Records of upland cattle egret colonies were found only in Central Texas, not other parts of the state. The habitat suitability model was constructed using total edge of three land use classes: water, forest, and developed classes. The model classified 78.6 % of upland colonies in very high or high suitability classes and 7.1% of colonies in low or very low suitability classes. This distribution was significantly different than expected considering the overall ratio of suitability scores in the entire raster model (p = 0.036). Nineteen active colonies were found in or bordering the Post Oak Savannah and Blackland Prairie ecoregions. Colonies were in residential, urban, island, and flooded tree and shrub habitat. Nests were found in 12 different tree and shrub species. Residential colonies had more breeding pairs, greater nest survival, and were less productive than non-residential colonies on average, but these differences were not statistically significant. Colonies where nest substrate was removed were not reused and no breeding was initiated nearby the next year. Propane cannons discouraged reuse of colony after prolonged application. Herons and egrets likely use residential sites when wetland habitats are limited. Their overall breeding distribution reflects state wide rainfall and wetland availability patterns with upland nesting in Central Texas, wetland nesting in eastern and coastal regions, and little large scale nesting in western Texas. Egrets and herons may use edges of development as breeding sites to limit predation by ground predators when flooded tree and shrub or island habitats are absent, but this hypothesis needs more testing.

Scleractinian corals increasingly are studied as geochemical archives of modern- and palaeoclimate, but microsampling for geochemical data is complicated by: 1) the microstructural complexity and spatial variability in skeletal growth in different coral genera; and 2) the rapidity and scale of diagenetic alteration that occurs in living coralla. Geochemical sampling techniques now have spatial resolution into the sub-micrometer to tens of micrometers range, and it is hoped that the spatial resolution can be translated to temporal resolution. This study investigated the effects on geochemical analyses imposed by microstructure and diagenesis in different live-collected coral genera representing somewhat different depositional environments. Suites of samples of four reef-building genera (Acropora, Pocillopora, Goniastrea and Porites) were collected from three adjacent environments in intertidal and subtidal positions near the reef edge at Heron Reef, Great Barrier Reef and studied by means of optical and scanning electron microscopy, combined with vibrational and energy dispersive spectroscopy. The first section of this study compares and documents the microstructure of the four coral genera. Each genus was found to have very different three-dimensional arrangements of microstructural elements, and a new general growth model was proposed for Acropora, to take into account differences in the timing of precipitation of trabeculae and thickening deposits. The results highlight the complexity and spatial variability of skeletal growth in different coral genera. Because microstructural patterns vary in different genera, direct observation of microstructural elements and growth lines are necessary to allow geochemical microsamples to be placed into series that represent temporal sequences with known degrees of time averaging. Coral growth rates (i.e., rates of extension) are discussed to determine the range of temporal relationships that exist between closely spaced skeletal microstructural elements. Such data are necessary in order for coral skeletogenesis to be understood and are critical for constraining microsampling strategies aimed at developing true time series geochemical data at very fine spatial and temporal scales. The second part of the study focused on early diagenetic alteration of the corals, which is an equally important concern for geochemical analysis. Early marine diagenesis was documented in the same live-collected samples of the four common reef-building coral genera. Samples show extensive early marine diagenesis where parts of the coralla less than three years old contain abundant macro- and microborings (sponges, algae, cyanobacteria and fungi) and significant amounts of aragonite, high-Mg calcite, low-Mg calcite and brucite [Mg(OH)2] cements. Many of the cements are associated with microendoliths and endobionts that inhabit recently abandoned parts of the skeleton. The cements are problematic for palaeoclimate reconstruction because geochemical proxies used for paleoclimate studies are meant to reflect ambient seawater chemistry and conditions, but the occurrence of brucite and low-Mg calcite demonstrates how far fluid chemistry in microenvironments within the corals has evolved from ambient seawater. Some Porites lobata specimens have had as much as 60% of the most recently deposited skeletal aragonite (i.e., the part of the skeleton that projects into the layer of living polyps) bored and replaced by low-Mg calcite cement. The low-Mg calcite cement has significantly different trace element ratios (Sr/Ca(mmol/mol) = 6.3 ± 1.4; Mg/Ca(mmol/mol) = 12.0 ± 5.1) than the host coral skeletal aragonite (Sr/Ca(mmol/mol) = 9.9 ± 1.3; Mg/Ca(mmol/mol) = 4.5 ± 2.3), thus providing a serious challenge for Sr/Ca or Mg/Ca based sea surface temperature calculations. This study illustrates that many diagenetic changes that can radically alter important geochemical characteristics of coral skeleton occur very early on the sea floor (i.e., while corals are still alive). Documented cements altered trace element inventories (e.g., Sr and Mg), thus, interfering with the use of those elements in palaeotemperature calculations. Hence, significant diagenetic changes that jeopardise palaeoclimate data do not require long-term diagenesis or meteoric exposure. Some of the diagenetic changes (e.g., calcite filled borings) occur at scales that are very difficult to detect short of visual inspection using SEM. Hence, vetting of coral samples with SEM is required before any sample is subjected to geochemical analysis.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves [424]-457). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves [424]-457). Also available on the Internet.

Submitted by Marcos Samuel (msamjunior@gmail.com) on 2017-06-09T13:08:24Z No. of bitstreams: 1 TRIÂNGULOS DE HERON Versão Final.pdf: 14272297 bytes, checksum: 09a56c4f9d4538d1f4c89aefff460726 (MD5) / Approved for entry into archive by Vanessa Reis (vanessa.jamile@ufba.br) on 2017-06-13T15:22:30Z (GMT) No. of bitstreams: 1 TRIÂNGULOS DE HERON Versão Final.pdf: 14272297 bytes, checksum: 09a56c4f9d4538d1f4c89aefff460726 (MD5) / Made available in DSpace on 2017-06-13T15:22:30Z (GMT). No. of bitstreams: 1 TRIÂNGULOS DE HERON Versão Final.pdf: 14272297 bytes, checksum: 09a56c4f9d4538d1f4c89aefff460726 (MD5) / Este trabalho propõe uma discussão sobre os triângulos de Heron. Um triângulo é dito heroniano se possui como medida de seus lados e de sua área números inteiros positivos. Veremos que todo triângulo retângulo de lados inteiros é heroniano e que esses são fáceis de determinar, o que não acontece com os demais membros dessa família. Apresentaremos também diversos métodos para gerar esses triângulos, além de explorar suas propriedades. Finalizaremos com a apresentação de duas atividades que podem ser aplicadas na Educação Básica.

Typescript. Includes vita and abstract. Bibliography: Includes bibliographical references (leaves 89-91). / A geometric model using idealized prey behaviors in reaction to wading bird disturbances was developed to hypothesize how wading bird foraging strategy might most efficiently counter those behaviors. The model suggests that for prey responding to wading bird disturbances with flight response distance strongly negatively correlated to their distance from the point of disturbance, wading birds could employ disturbance facilitated social foraging strategy, thereby increasing individual foraging efficiency and selecting for social foraging. In controlled studies of the reactive behaviors of two primary prey species seen to be taken at disparate rates by solitary and socially foraging herons, schooling Shiner Surfperch exhibited behaviors favoring social foraging in herons, while Staghorn Sculpins exhibited no correlation in their flight response distances relative to their proximity to the disturbance, and seemed unlikely to be more efficiently utilized by socially foraging wading birds.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / O presente trabalho tem por objetivo motivar os estudantes a se interessarem por problemas de mÃnimos geomÃtricos, em especial relacionados à simetrias, atravÃs do uso do software educacional Geogebra. Fornecendo um guia de atividades que podem ser aplicadas em sala de aula. Trata do Problema de Heron e do Problema de Fermat, apresentando suas respectivas resoluÃÃes e algumas variaÃÃes interessantes. / His paper has the objective of motivate the students to interest for problems of geometric minimuns, specially those related to symmetry, using the educational software Geogebra. Providing a guide of activities that can be used in classes. Treats about Heronâs Problem and Fermatâs Problem, presenting the resolutions and same interesting variations.

Work includes choosen properties and problems pair with Heronian triangles. It's available like mathematical utility for work in special-interest mathematics on secondary school.

Orientador: Prof. Dr. Márcio Fabiano da Silva / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Mestrado Profissional em Matemática em Rede Nacional, 2017. / Neste trabalho,apresentamos um estudos obre os triângulos que possuem lados e área de medidas inteiras,doravante chamados de Triângulos Heronianos, muito estudados na teoria dos números a partir da fórmula de Heron,que relaciona a área de um triângulo aos seus três lados.Este tema traz o desafio de se encontrar triplas de inteiros que satisfaçam as condições da fórmula de Heron, problema este já resolvido desde o século VI pelo matemático indiano Brahmagupta por meio de parametrizações. Outro fator enriquecedor deste estudo é que esta classe de triângulos apresenta diversas propriedades que, apesar de não serem óbvias,podem ser demonstradas com conceitos de matemática básica,viabilizando o seu ensino nas aulas regulares de matemática. / In this work, we present a study on the triangles that have sides and area that are all integers, hance called Heronian Triangles, well studied in nnumber theory based on Heron¿s formula, which relates the area of a triangle to its three sides.This theme brings the challenge of finding triples of integers that satisfy the conditions of Heron¿s formula, a problem that has been solved since the sixth century by the Indian mathematician Brahmagupta by means of parametrizations. Another enriching factor of this study is that this class of triangles presents several properties that,although not obvious, can be demonstrated with concepts of basic mathematics,facilitating their teaching in regular math classes.