Investigating Stainless Steel Particle Synthesis

This thesis focuses on the chemistry for stainless nanoparticle synthesis in order to develop corrosion resistant nanoparticles. Syntheses within the Maye lab have been successful, however at the large scale these processes have been hindered by low yields as a result of byproduct formation and oxidation loss. This study addresses these problems by introducing a new precursor to synthesize the Fe core of FeCr/Ni stainless core/shell particles. Traditionally iron pentacarbonyl (Fe(CO)5 is used, but this study uses iron acetylacetonate (Fe(acac)3) as a substitute. Although the degradation of Fe(CO)5 is more commonly used and is understood relatively well, Fe(acac)3 is safer and less costly. Properly synthesized particles show high crystallinity and have immense magnetic capabilities. A comparison between the two precursors is completed in this work. The ability for Fe0 particles to act as a core for stainless particles and the effects of shells on the cores is also analyzed. Analysis of the particles was done using thermogravimetric analysis (TGA), Laser Ablation Induced Coupled Plasma Mass Spectrometry (LA-ICPMS), Physical Property Measurement System (PPMS), and x-ray diffraction (XRD). These analysis methods allow for the approximate composition of the particles to be determined and the approximate extent of oxidation to be estimated. Results of the study show that Fe(acac)3 iron particles are less metallic than Fe(CO)5, suggesting that Fe(acac)3 is not an effective substitute for Fe(CO)5. This shows that further research needs to be completed in order to find a potential substitute or create a new route for the successful creation of stainless nanoparticles

Price dispersion in Uruguay

Retail prices for a product vary across time and places. The sources that drive price disp ersion can be grouped into three categories: (i) price diffrences across markets, (ii) price diferences across stores in a market, and (iii) within-store price variation over time. I find there is price dispersion in the retail market in Uruguay. The decomposition shows that 39.16 percent is across-markets, 36.90 percent corresponds to across-store, and 23.94 percent over time. These results highlight the relevance of intertemporal pricing strategies of stores, and how they set prices at the local market to understand price dispersion. Nevertheless, in recent years across-market price dispersion has been increasing, which can imply a structural change of price dispersion sources. The price dispersion phenomenon and its decomposition are heterogeneous. Across products, stores, and over time I find differences in price dispersion as well as differences in the sources behind it

How many species of drosophila (Diptera, Drosophilidae) remain to be described in the forests of São Paulo, Brazil?: species lists of three forest remnants

This paper describes the composition and abundance of Drosophila species found in three forest remnants in the State of São Paulo. A well-standardized sampling procedure applied on four collecting trips to the same sites on four areas resulted on 944 samples. All males collected were identified by analyses of the genitalia, this being the only data set used. One hundred and twenty five species were detected amongst the 29,289 males analyzed. From them 57,6% could be identified as described species. Thirteen of the species found were absent from the previous species list for the state of São Paulo State, thus represent an increase of 13% on the number known. We argue that the majority of the 53 unidentified species are in fact undescribed. The sites studied did not differ significantly in the proportion of identified species. On average identified species were almost seven times more abundant than unidentified ones, and this difference was significant. Rarefaction curve analysis confirmed that the proportion of unidentified species increase with sample size, and did not reach a plateau with our data set. These results illustrate the large richness of Drosophila species in forest remnants of São Paulo State. It also indicates that about half of the species in this region remain to be described. This conclusion is particularly important when one considers that this is a well studied genus of Diptera, on the best sampled region of Brazil.Este trabalho descreve a composição e a abundância de espécies de Drosophila encontradas em três remanescentes florestais do estado de São Paulo. Um procedimento de coletas bem padronizado aplicado em quatro coletas nos mesmos sítios em três áreas resultou em 944 amostras. Todos os machos coletados foram identificados pela análise da genitália, e apenas os dados destes foram analisados. Cento e vinte e cinco espécies foram detectadas entre os 29.289 machos analisados. Destas 57,6% puderam ser identificadas como espécies já descritas. Treze das espécies encontradas estavam ausentes da lista prévia de espécies do estado de São Paulo, resultado em um aumento de 13% nesta lista. A maioria das 53 espécies não identificadas são, provavelmente, não descritas. Os sítios estudados não diferem significativamente na proporção de espécies identificadas. Em média as espécies identificadas foram quase sete vezes mais abundantes do que as não identificadas, e esta diferença foi significativa. Uma análise de curvas de rarefação confirmou que a proporção de espécies não identificadas aumenta com o tamanho amostral, e não atinge um platô em nosso conjunto de dados. Estes resultados ilustram a grande riqueza de espécies de Drosophila nos remanescentes florestais do estado de São Paulo. Eles também indicam que cerca de metade das espécies desta região ainda não foram descritas. Esta conclusão mostra-se particularmente importante considerando que este é um gênero de Diptera bem estudado, na região mais bem amostrada do Brasil.011

Comunicação comunitária no bairro Eldorado dos Carajás: processos de construção discursiva e ideológica

O presente artigo visa apresentar o projeto de pesquisa aprovado pelo programa de Mestrado em Divulgação Científica e Cultural oferecido pelo Labjor/IEL – Unicamp. Inserida no “Projeto Barracão: Eldorado dos Carajás, desenvolvido pelo Laboratório de Estudos Urbanos” (Labeurb/Nudecri – Unicamp), a pesquisa se propõe a refletir o funcionamento dos processos de produção discursiva e ideológica nas mídias comunitárias. Para isso, desenvolveremos oficinas junto aos adolescentes do Eldorado dos Carajás, bairro da periferia de Campinas, a fim de que eles possam produzir um boletim de notícias impresso e um blog virtual. O objetivo é que os adolescentes produzam integralmente esses materiais, desde o conteúdo, como os textos, fotografias e vídeos; até a parte visual, como a diagramação das páginas impressa e online. Todo o processo de elaboração e desenvolvimento das oficinas, bem como os materiais produzidos nelas, constituirão nosso objeto de análise. Avaliaremos assim o discurso produzido, os efeitos sócio-histórico no local e a forma como o exercício do político ocorrerá na produção de mídias comunitárias no bairro

Chromosomal localization of microsatellite loci In drosophila mediopunctata

Drosophila mediopunctata has been used as a model organism for genetics and evolutionary studies in the last three decades. A linkage map with 48 microsatellite loci recently published for this species showed five syntenic groups, which had their homology determined to Drosophila melanogaster chromosomes. Then, by inference, each of the groups was associated with one of the five major chromosomes of D. mediopunctata. Our objective was to carry out a genetic (chromosomal) analysis to increase the number of available loci with known chromosomal location. We made a simultaneous analysis of visible mutant phenotypes and microsatellite genotypes in a backcross of a standard strain and a mutant strain, which had each major autosome marked. Hence, we could establish the chromosomal location of seventeen loci; including one from each of the five major linkage groups previously published, and twelve new loci. Our results were congruent with the previous location and they open new possibilities to future work integrating microsatellites, chromosomal inversions, and genetic determinants of physiological and morphological variation3815558CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES

Species tree estimation for a deep phylogenetic divergence in the New World monkeys (Primates: Platyrrhini)

The estimation of a robust phylogeny is a necessary first step in understanding the biological diversification of the platyrrhines. Although the most recent phylogenies are generally robust, they differ from one another in the relationship between Aotus and other genera as well as in the relationship between Pitheciidae and other families. Here, we used coding and non-coding sequences to infer the species tree and embedded gene trees of the platyrrhine genera using the Bayesian Markov chain Monte Carlo method for the multispecies coalescent (*BEAST) for the first time and to compared the results with those of a Bayesian concatenated phylogenetic analysis. Our species tree, based on all available sequences, shows a closer phylogenetic relationship between Atelidae and Cebidae and a closer relationship between Aotus and the Cebidae clade. The posterior probabilities are lower for these conflictive tree nodes compared to those in the concatenated analysis; this finding could be explained by some gene trees showing no concordant topologies between Aotus and the other genera. Moreover, the topology of our species tree also differs from the findings of previous molecular and morphological studies regarding the position of Aotus. The existence of discrepancies between morphological data, gene trees and the species tree is widely reported and can be related to processes such as incomplete lineage sorting or selection. Although these processes are common in species trees with low divergence, they can also occur in species trees with deep and rapid divergence. The sources of the inconsistency of morphological and molecular traits with the species tree could be a main focus of further research on platyrrhines.Fil: Perez, Sergio Ivan. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Antropología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Klaczko, Julia. Universidade Estadual de Campinas; BrasilFil: dos Reis, Sérgio F.. Universidade Estadual de Campinas; Brasi

Gestão de recursos comuns : regras de uso e padrões de captura de quelônios no Baixo Rio Negro/AM

Dissertação (mestrado)—Universidade de Brasília, Centro de Desenvolvimento Sustentável, Programa de Pós-Graduação em Desenvolvimento Sustentável, 2018.A caça de subsistência, notadamente dos quelônios aquáticos, é uma atividade presente em unidades de conservação no Brasil, a exemplo da Reserva Extrativista do Rio Unini e adjacências, no Estado do Amazonas. A fauna silvestre, sob a ótica dos recursos de uso comum, deve ter seu uso regulado por algum regime de propriedade e por instituições adequadas a realidade local para que a gestão possa ter sucesso no que se refere a aliar a necessidade de conservação das espécies com as necessidades dos usuários locais do recurso. Por outro lado, a caça no Brasil ainda é um tema controverso juridicamente, o que dificulta a implementação de medidas de manejo oficialmente reconhecidas e fragiliza a gestão do recurso. Nesse sentido, esta pesquisa analisou a gestão dos quelônios aquáticos na bacia do rio Unini com o objetivo de entender como instituições formais e informais afetam o uso e a conservação dos quelônios aquáticos. Foram levantadas e classificadas as instituições formais e informais estabelecidas para a gestão dos quelônios na bacia do Unini, e realizada análise de consenso, baseada em entrevistas estruturadas, que constatou que a maioria das instituições são conhecidas e compartilhadas pelos usuários do recurso, mas que algumas das regras constitucionais não têm aderência ao contexto local, o que dificulta a gestão sustentável do recurso. No que se refere ao consumo de quelônios para subsistência feito pelas dez comunidades ribeirinhas do Unini, foram analisados os dados de oito anos de monitoramento para quatro espécies mais consumidas (a tartaruga-da-amazônia Podocnemis expansa, o tracajá Podocnemis unifilis, a irapuca Podocnemis erythrocephala e o cabeçudo Peltocephalus dumerilianus). Constatou-se que a quantidade de quelônios capturados por família no rio Unini não apresentou diferenças significativas ao longo do tempo, e não apresentam uma tendência nem de aumento nem de diminuição do consumo; e que a composição espacial das capturas nas comunidades e no uso de habitats manteve um padrão consolidado ao longo do tempo. A análise das regras formais e informais existentes para a gestão dos quelônios no Unini, e dos padrões de captura de quelônios pelas comunidades demonstram que não existem regras ligadas diretamente ao consumo de quelônios. Os padrões de captura observados deveriam subsidiar adaptações às regras operacionais e de escolha coletiva, adaptadas a realidade local, o que não vem ocorrendo. Esse diagnóstico geral das instituições e dos padrões de captura contribuem para o entendimento da gestão dos quelônios aquáticos no rio Unini e são informações básicas para o delineamento de estratégias de gestão e medidas de manejo que visem à sustentabilidade social, econômica e ambiental. Conclui-se que, apesar de ainda serem necessários avanços relacionados a alguns aspectos, de forma geral, os mecanismos de gestão presentes na RESEX do Unini vão ao encontro dos princípios desejados (design principles) para a governança dos recursos de uso comum e, portanto, são promissores para a manutenção de instituições robustas para a gestão dos recursos naturais da área.In the last few decades, the contributions of common pool resources (CPR) researches were important to the understanding how to accomplish the common management of natural resources without overexploitation. Formal and informal institutions play a key role in resource management, assuring the essential conditions for rules compliance, and working as effective regulators of resources use. Subsistence hunting, notably of aquatic chelonians, is a typical activity in Brazilian protected areas, as the reserve of sustainable use of Unini River, in the Amazonas State. Nevertheless, as usual for all CPR, chelonian subsistence hunting must be regulated in order to reconcile conservation and use. On the other hand, hunting in Brazil is still a controversial issue, from the legal perspective. This can dramatically hamper any management measure, so consequently wildlife hunting will be prone to the open access. In this study, we analyzed institutions established in the Unini River Basin for chelonian management, which operate, formally and informally, through three different levels: operational, collective choice and constitutional. We found no adherence for national rules in local scale, which can be detrimental to the sustainable use of chelonians. We also analyzed eight years long monitoring data for the four most commonly used chelonian species (Podocnemis expansa, Podocnemis unifilis, Podocnemis erythrocephala e Peltocephalus dumerilianus) by ten Unini riverine communities. We found no significant variation in chelonian use through the years. Results show which chelonian species are most hunted, which habitats are most exploited and in what time of the year chelonians are most consumed. These are basic information for efficient decision making in management strategies. Some hunting patterns we have found indicate the need for management rules appropriate to the local context that actually does not exist today. Despite the need for improvements in some aspects, we conclude that current governance system for chelonian species corroborates design principles and therefore can maintain robust institutions for Unini River natural resource management

Variation and heritability of aristal morphology in a natural population of Drosophila mediopunctata

We studied the major sources influencing the variation of the number of aristal branches in a natural population of Drosophila mediopunctata. Flies were collected on six occasions at different altitudes in Parque Nacional do Itatiaia (Brazil). The progenies of these flies were reared in the laboratory at 16.5 degrees C. The number of aristal branches ranges from 11 to 15 and is influenced by sex. Estimates of the natural heritability showed that at least 20% of the total phenotypic variation is due to additive genetic variation. Although the heritability of this trait estimate in the laboratory was larger (42%), the difference between the two estimates is not statistically significant. Thus, for the number of aristal branches, laboratory estimates of heritability provide reasonable estimations of both the magnitude and significance of heritabilities in nature. The mean numbers of aristal branches in the wild-caught flies from different altitudes or months are homogeneous. The same was observed for the means of its progeny kept in the laboratory under controlled conditions. On the other hand, wild-caught females have significantly fewer aristal branches than their laboratory-raised daughters, which suggests that an environmental factor or factors may have an important influence on this trait.1281677

Genitals evolve faster than other traits in Anolis lizards

Organismic and Evolutionary Biolog

Are diet preferences associated to skulls shape diversification in xenodontine snakes?

Snakes are a highly successful group of vertebrates, within great diversity in habitat, diet, and morphology. The unique adaptations for the snake skull for ingesting large prey in more primitive macrostomatan snakes have been well documented. However, subsequent diversification in snake cranial shape in relation to dietary specializations has rarely been studied (e.g. piscivory in natricine snakes). Here we examine a large clade of snakes with a broad spectrum of diet preferences to test if diet preferences are correlated to shape variation in snake skulls. Specifically, we studied the Xenodontinae snakes, a speciose clade of South American snakes, which show a broad range of diets including invertebrates, amphibians, snakes, lizards, and small mammals. We characterized the skull morphology of 19 species of xenodontine snakes using geometric morphometric techniques, and used phylogenetic comparative methods to test the association between diet and skull morphology. Using phylogenetic partial least squares analysis (PPLS) we show that skull morphology is highly associated with diet preferences in xenodontine snakes.Julia Klaczko, Emma Sherratt, Eleonore Z. F. Set