O presente trabalho é a continuação das pesquisas anteriores relacionadas às rochas metamáficas e metaultramáficas da região de Arroio Grande, sudeste do Escudo Sul-rio-grandense. A partir de estudos de campo, microscopia óptica, microscopia eletrônica de varredura e difratometria de raios X, essa associação de rochas (anfibolitos, serpentinitos cromíferos, xistos magnesianos, micaxistos, quartzitos e mármores) foi interpretada como possíveis fragmentos de crosta oceânica relacionados ao encerramento de um paleo-oceano durante o ciclo orogênico Brasiliano/Pan-Africano no Neoproterozoico e denominada de Complexo Ofiolítico Arroio Grande. Nesta dissertação é apresentada uma breve descrição deste complexo ofiolítico e o seu contexto geológico, além de breves considerações sobre sua importância do ponto de vista da evolução do paleocontinente Gondwana Ocidental durante o Neoproterozoico. Em seguida, é apresentado o artigo denominado “Geologia da associação metamáfica-ultramáfica da região de Arroio Grande, sudeste do Escudo Sul-rio-grandense”, aceito para publicação no periódico Pesquisas em Geociências da Universidade Federal do Rio Grande do Sul, no qual são caracterizadas as unidades metamáficas e metaultramáficas do referido complexo. Tais pesquisas têm como principal objetivo adicionar novos dados aos já existentes na literatura, aquecendo as discussões acerca da existência ou não de possíveis ofiolitos na porção oriental do Escudo Uruguaio-Sul-rio-grandense relacionados à ocorrência do paleo-oceano Adamastor, e dos modelos evolutivos para a reconstrução do paleocontinente Gondwana Ocidental. / The present work is the continuation of previous researches related to the metamafic and meta-ultramafic rocks located near the town of Arroio Grande, southeastern Sul-rio-grandense Shield. Through fieldwork, optical microscopy, scanning electron microscopy and X-ray diffraction, this rock association (amphibolites, chromian serpentinites, magnesian schists, mica schists, quartzites and marbles) was interpreted as possible slices of an oceanic crust related to the closure of a paleo-ocean during the Brasiliano/Pan-African orogenic cycle and called Arroio Grande Ophiolitic Complex. A brief description of this ophiolitic complex and his geological setting is presented in this dissertation, with brief considerations on their importance, from the point of view of the Western Gondwana paleocontinent evolution during the Neoproterozoic Era. Subsequently, the article entitled "Geology of the Arroio Grande meta-mafic-ultramafic association, southeastern Sul-riograndense Shield”, accepted for publication in the Pesquisas em Geociências Journal of the Rio Grande do Sul Federal University is presented, where the metamafic and meta-ultramafic units of the aforesaid complex are characterized. Such researches have as main objective to add new data to existing literature, promoting discussions about the possible existence of ophiolites related to the occurrence of the Adamastor paleo-ocean in the eastern portion of the Uruguaio-Sul-rio-grandense Shield and about geologic evolution models for the reconstruction of Western Gondwana paleocontinent.

O Granito Chasqueiro aflora como campos de matacões e lajeados que em planta formam um corpo alongado segundo N50o E com área de aproximadamente 400 km2 localizada no sul da porção oriental do Escudo Sul-Rio-Grandense. Constitui-se de monzo a sienogranito, leucocrático de cor cinza-claro e textura porfirítica com megacristais de K-feldspatos em matriz equigranular, hipidiomórfica grossa, composta por quartzo, K-feldspato, plagioclásio, biotita, hornblenda, opacos (magnetita, hematita) e acessórios (zircão, titanita, apatita e alanita). Os megacristais atingem proporções modais entre 30 a 60 % e variam entre 4 e 8 cm que junto com os minerais máficos da matriz evidenciam uma foliação de fluxo magmático subvertical bem desenvolvida que transaciona lateralmente para uma foliação tectônica nos bordos do granito próximo as zonas de cisalhamento onde ocorrem extensas faixas marcadas por intensa deformação dúctil e geração de protomilonitos. O granito apresenta enclaves máficos microgranulares de composição diorítica apresentando diferentes formas e tamanhos. Geoquimicamente é caracterizado por um magmatismo subalcalino do tipo cálcio-alcalino alto potássio, metaluminoso a levemente peraluminoso, com assinatura característica de granitos gerados em ambiente póscolisional. Processos de fusão crustal, mistura de magmas e cristalização fracionada são sugeridos para a sua evolução. Análises geocronológicas obtidas pelo método UPb (LA-ICPMS) e geoquímica isotópica de Lu-Hf (LA-ICPMS) em zircões do granito indicaram, respectivamente, idade de cristalização 574 ± 3 Ma e valores negativos para εHf sugerindo assim uma relação do granito com o evento deformacional D2 e fontes magmáticas dominantemente crustais com participação de componente mantélico subordinado. / Chaqueiro Granite emerges as boulders fields and slabs that in plant form an elongated body at N50o E with an area of approximately 400 km2 located at the southernmost portion of the eastern Sul-Rio-Grandense Shield, RS. It consists of monzo the syenogranite, light gray and leucocratic porphyritic texture with megacrystals K-feldspar in a coarse equigranular hypidiomorphic matrix, composed of quartz, K-feldspar, plagioclase, biotite, hornblende, opaque minerals and accessories. The modal megacrystals reach proportions between 30 and 60 % and range from 4 and 8 cm together with mafic minerals of the matrix showing a subvertical magmatic foliation and a tectonic foliation prominent in the borders marked by intense ductile deformation and protomylonite generation. Another important aspect of the Chasqueiro Granite is the presence of microgranular mafic enclaves of dioritic composition ubiquitous in the granite, having different shapes and sizes. Geochemically the granite is characterized as a slightly expanded acid sequence formed by a sub-alkaline magmatism of calc-alkaline type with high potassium, metaluminous to lightly peraluminous, with characteristic signature of granites generated in post-collisional tectonic setting. Geochronological analyzes obtained by the U-Pb method (LA-ICPMS) and isotope geochemistry of Lu-Hf (LA-ICPMS) in zircons presenting, respectively, crystallization age 574 ± 3 Ma and negative εHf which suggest a granite relationship with deformational event D2 and supporting a magmatic crustal sources with subordinate mantle component.

O Granito Chasqueiro aflora como campos de matacões e lajeados que em planta formam um corpo alongado segundo N50o E com área de aproximadamente 400 km2 localizada no sul da porção oriental do Escudo Sul-Rio-Grandense. Constitui-se de monzo a sienogranito, leucocrático de cor cinza-claro e textura porfirítica com megacristais de K-feldspatos em matriz equigranular, hipidiomórfica grossa, composta por quartzo, K-feldspato, plagioclásio, biotita, hornblenda, opacos (magnetita, hematita) e acessórios (zircão, titanita, apatita e alanita). Os megacristais atingem proporções modais entre 30 a 60 % e variam entre 4 e 8 cm que junto com os minerais máficos da matriz evidenciam uma foliação de fluxo magmático subvertical bem desenvolvida que transaciona lateralmente para uma foliação tectônica nos bordos do granito próximo as zonas de cisalhamento onde ocorrem extensas faixas marcadas por intensa deformação dúctil e geração de protomilonitos. O granito apresenta enclaves máficos microgranulares de composição diorítica apresentando diferentes formas e tamanhos. Geoquimicamente é caracterizado por um magmatismo subalcalino do tipo cálcio-alcalino alto potássio, metaluminoso a levemente peraluminoso, com assinatura característica de granitos gerados em ambiente póscolisional. Processos de fusão crustal, mistura de magmas e cristalização fracionada são sugeridos para a sua evolução. Análises geocronológicas obtidas pelo método UPb (LA-ICPMS) e geoquímica isotópica de Lu-Hf (LA-ICPMS) em zircões do granito indicaram, respectivamente, idade de cristalização 574 ± 3 Ma e valores negativos para εHf sugerindo assim uma relação do granito com o evento deformacional D2 e fontes magmáticas dominantemente crustais com participação de componente mantélico subordinado. / Chaqueiro Granite emerges as boulders fields and slabs that in plant form an elongated body at N50o E with an area of approximately 400 km2 located at the southernmost portion of the eastern Sul-Rio-Grandense Shield, RS. It consists of monzo the syenogranite, light gray and leucocratic porphyritic texture with megacrystals K-feldspar in a coarse equigranular hypidiomorphic matrix, composed of quartz, K-feldspar, plagioclase, biotite, hornblende, opaque minerals and accessories. The modal megacrystals reach proportions between 30 and 60 % and range from 4 and 8 cm together with mafic minerals of the matrix showing a subvertical magmatic foliation and a tectonic foliation prominent in the borders marked by intense ductile deformation and protomylonite generation. Another important aspect of the Chasqueiro Granite is the presence of microgranular mafic enclaves of dioritic composition ubiquitous in the granite, having different shapes and sizes. Geochemically the granite is characterized as a slightly expanded acid sequence formed by a sub-alkaline magmatism of calc-alkaline type with high potassium, metaluminous to lightly peraluminous, with characteristic signature of granites generated in post-collisional tectonic setting. Geochronological analyzes obtained by the U-Pb method (LA-ICPMS) and isotope geochemistry of Lu-Hf (LA-ICPMS) in zircons presenting, respectively, crystallization age 574 ± 3 Ma and negative εHf which suggest a granite relationship with deformational event D2 and supporting a magmatic crustal sources with subordinate mantle component.

Este trabalho tem como objetivo investigar os processos controladores da mobilidade e concentração de níquel (Ni) em rochas ultramáficas serpentinizadas no Escudo Sul-Riograndense (ESrg), Rio Grande do Sul (RS), Brasil. A composição primária das rochas ultramáficas hospedeiras de Ni constitui um parâmetro relevante, mas os processos secundários são os controladores mais importantes dessas mineralizações, principalmente a serpentinização, pressupondo-se que o Ni possa migrar da olivina ou metamórfica para os minerais do grupo das serpentinas. Para a caracterização mineralógica e textural das rochas ultramáficas serpentinizadas da porção oeste do ESrg, foram aplicadas técnicas de petrografia e Microscopia Eletrônica de Varredura. Para a análise química dos elementos em rocha total foi realizada fluorescência de Raios-X, ICP e ICP-MS. Estas técnicas permitiram classificar quimicamente as rochas e relacionar a variação da intensidade dos eventos metassomáticos, metamórficos e hidrotermais que modificaram a mineralogia dos protólitos. No entanto, foram necessárias estudos de detalhe dos minerais individuais, notadamente olivinas e serpentinas com o uso da microssonda eletrônica para determinar as concentrações de Ni e suas variações nos diferentes corpos ultramáficos investigados. Dessa forma, foi possível quantificar e identificar os minerais concentradores de Ni e a relação dos eventos com a mobilidade e concentração dos elementos. Os resultados de microssonda indicam que as olivinas dos peridotitos do Maciço Pedras Pretas possuem baixos teores de níquel que variam de 0,13% a 0,21% e a média é 0,17%, enquanto que as olivinas dos harzburgitos da Sequência Cerro Mantiqueiras possuem teores mais elevados na média de 0,31%. As olivinas do Pedras Pretas possuem composição homogênea enquanto que aquelas do Cerro Mantiqueiras mostram variações composicionais importantes com conteúdo de Fo 92-98 e teores de níquel entre 0,3% e 0,4%. Tais variações no Cerro Mantiqueiras podem estar relacionadas a diferenças na composição do protólito ou a outro fator desconhecido que necessita futuras investigações. As olivinas e serpentinas no Cambaizinho e Serrinha mostram valores de níquel entre 0,19% a 0,3%, comparáveis ao Cerro Mantiqueiras, porém bem mais elevados que o Pedras Pretas. Este estudo mostra que os corpos ultramáficos do Cambaizinho- Serrinha e Cerro Mantiqueiras possuem potencial para desenvolver depósitos de Ni não sulfetado devido as concentrações relativamente elevadas de Ni nas olivinas. Entretanto, tais depósitos não se desenvolveram devido a dois fatores principais: o primeiro está ligado à superposição de eventos de metamorfismo e deformação recorrentes no tempo e no espaço que propiciaram a mobilização do Ni; o segundo fator é atribuído a ausência de agentes supergênicos favoráveis para a formação de depósitos lateríticos como os observados na região norte do Brasil. / This paper investigates the processes controlling the mobility and concentration of nickel (Ni) in serpentinized ultramafic rocks in the Sul- Riograndense Shield (ESrg), Rio Grande do Sul (RS), Brazil. The primary composition of the ultramafic Ni host is a relevant parameter, but the secondary processes are the almost important controllers of these mineralizations, mainly serpentinization, assuming that Ni may migrate from igneous or metamorphic olivine minerals to the group of serpentine this phase. For the mineralogical and textural characterization of the serpentinized ultramafic rocks of the western portion of ESrg, were applied techniques of petrographic and scanning electron microscopy. For chemical analysis of elements in rock whole was performed X-ray fluorescence, ICP and ICP-MS. Although these techniques allow chemically classification of rocks and relate the variation of intensity in which metasomatics, metamorphic and hydrothermal events, changed the that mineralogy of the rock, however analysis of individual mineral detail, notably olivine and serpentine minerals using the electron microprobe detail, were necessary to determine the concentrations of Ni and variations in different ultramafic bodies investigated. Thus, it was possible to quantify and identify the Ni concentrators minerals and the relationship of events with the mobility and concentration of the elements. The microprobe results indicate that the olivine of peridotite Pedras Pretas have low contents of NiO ranging from 0.13% to 0.21% and averaged 0.17%, while the olivine harzburgites Cerro Mantiqueiras have higher levels of NiO averaging 0.31%. The olivine of Pedras Pretas have a homogeneous composition as those of Cerro Mantiqueiras show important compositional variations with a content of forsterite the Fo 92-98 and NiO contents of between 0.20% and 0.40%. Such variations in Cerro Mantiqueiras may be related to differences in the composition of the protolith or another unknown factor that needs further investigation. The olivine and serpentine in Cambaizinho and Serrinha, show NiO values between 0.19 % to 0.3 %, values comparable to the Cerro Mantiqueiras, but higher than the Pedras Pretas. This study shows that the Cambaizinho, Serrinha and Cerro Mantiqueiras have the potential to develop non- sulphide Ni deposits, due high Ni concentrations in olivine. However, these deposits are not developed due two main factors: the first is linked to the superposition of events the metamorphism and deformation applicants in time and space, that enabled the Ni mobilization; the second factor is attributed to lack preservation of profiles suitable for the Ni concentration, due to uplift and erosion lateritic subsequent.

O presente trabalho é a continuação das pesquisas anteriores relacionadas às rochas metamáficas e metaultramáficas da região de Arroio Grande, sudeste do Escudo Sul-rio-grandense. A partir de estudos de campo, microscopia óptica, microscopia eletrônica de varredura e difratometria de raios X, essa associação de rochas (anfibolitos, serpentinitos cromíferos, xistos magnesianos, micaxistos, quartzitos e mármores) foi interpretada como possíveis fragmentos de crosta oceânica relacionados ao encerramento de um paleo-oceano durante o ciclo orogênico Brasiliano/Pan-Africano no Neoproterozoico e denominada de Complexo Ofiolítico Arroio Grande. Nesta dissertação é apresentada uma breve descrição deste complexo ofiolítico e o seu contexto geológico, além de breves considerações sobre sua importância do ponto de vista da evolução do paleocontinente Gondwana Ocidental durante o Neoproterozoico. Em seguida, é apresentado o artigo denominado “Geologia da associação metamáfica-ultramáfica da região de Arroio Grande, sudeste do Escudo Sul-rio-grandense”, aceito para publicação no periódico Pesquisas em Geociências da Universidade Federal do Rio Grande do Sul, no qual são caracterizadas as unidades metamáficas e metaultramáficas do referido complexo. Tais pesquisas têm como principal objetivo adicionar novos dados aos já existentes na literatura, aquecendo as discussões acerca da existência ou não de possíveis ofiolitos na porção oriental do Escudo Uruguaio-Sul-rio-grandense relacionados à ocorrência do paleo-oceano Adamastor, e dos modelos evolutivos para a reconstrução do paleocontinente Gondwana Ocidental. / The present work is the continuation of previous researches related to the metamafic and meta-ultramafic rocks located near the town of Arroio Grande, southeastern Sul-rio-grandense Shield. Through fieldwork, optical microscopy, scanning electron microscopy and X-ray diffraction, this rock association (amphibolites, chromian serpentinites, magnesian schists, mica schists, quartzites and marbles) was interpreted as possible slices of an oceanic crust related to the closure of a paleo-ocean during the Brasiliano/Pan-African orogenic cycle and called Arroio Grande Ophiolitic Complex. A brief description of this ophiolitic complex and his geological setting is presented in this dissertation, with brief considerations on their importance, from the point of view of the Western Gondwana paleocontinent evolution during the Neoproterozoic Era. Subsequently, the article entitled "Geology of the Arroio Grande meta-mafic-ultramafic association, southeastern Sul-riograndense Shield”, accepted for publication in the Pesquisas em Geociências Journal of the Rio Grande do Sul Federal University is presented, where the metamafic and meta-ultramafic units of the aforesaid complex are characterized. Such researches have as main objective to add new data to existing literature, promoting discussions about the possible existence of ophiolites related to the occurrence of the Adamastor paleo-ocean in the eastern portion of the Uruguaio-Sul-rio-grandense Shield and about geologic evolution models for the reconstruction of Western Gondwana paleocontinent.

A presente investigação tem por objetivo um estudo aprofundado da imagética dos escudos gregos dos séculos VI a.C. e V a.C. Nossa intenção é a de realizar um levantamento sistemático das imagens figuradas nestes escudos com a finalidade de melhor explicitar a natureza deste equipamento defensivo e de melhor compreender a disposição do homem grego diante da guerra. / This thesis presents a systematic study of the emblems depicted on the Greek shield. Our goal is to better understand the nature of this defensive equipment and the disposition of the ancient Greeks towards war.

Toxoplasmosis is an opportunistic disease caused by the protozoan parasite Toxoplasma gondii. The parasite is usually staved off by a healthy immune system and remains dormant in the body. In immunocompromised patients, the parasite can become active and spread throughout the body causing symptoms such as encephalitis, cognitive disorders, seizures, and death. Combination drug therapy is the usual treatment for toxoplasmosis; however, patients suffer from problems of intolerance, allergic reactions, and cytotoxicity. In an effort to identify new drug targets for toxoplasmosis, a series of compounds have been synthesized that can be used as tools to probe the unique pathways used by T. gondii to survive in the human host. One class of these compounds is pyridinyl imidazoles, which have been shown to be active against T. gondii MAP kinases. To set up a protein pull down assay, a biotinylated linker was synthesized. We have also synthesized a compound that’s being used to study the pathways involved in the most active and proliferative form of T. gondii.

Craton cores far from plate boundaries have traditionally been viewed as stable features that experience minimal vertical motion over 100-1000Ma time scales. Here we show that the Fennoscandian Shield in southeastern Sweden experienced several episodes of burial and exhumation from similar to 1800Ma to the present. Apatite, titanite, and zircon (U-Th)/He ages from surface samples and drill cores constrain the long-term, low-temperature history of the Laxemar region. Single grain titanite and zircon (U-Th)/He ages are negatively correlated (104-838Ma for zircon and 160-945Ma for titanite) with effective uranium (eU=U+0.235xTh), a measurement proportional to radiation damage. Apatite ages are 102-258Ma and are positively correlated with eU. These correlations are interpreted with damage-diffusivity models, and the modeled zircon He age-eU correlations constrain multiple episodes of heating and cooling from 1800Ma to the present, which we interpret in the context of foreland basin systems related to the Neoproterozoic Sveconorwegian and Paleozoic Caledonian orogens. Inverse time-temperature models constrain an average burial temperature of similar to 217 degrees C during the Sveconorwegian, achieved between 944Ma and 851Ma, and similar to 154 degrees C during the Caledonian, achieved between 366Ma and 224Ma. Subsequent cooling to near-surface temperatures in both cases could be related to long-term exhumation caused by either postorogenic collapse or mantle dynamics related to the final assembly of Rodinia and Pangaea. Our titanite He age-eU correlations cannot currently be interpreted in the same fashion; however, this study represents one of the first examples of a damage-diffusivity relationship in this system, which deserves further research attention.

Since 2000, a relatively new electric thruster concept has been in research, development, and production at Thales Electron Devices in Germany. This High Efficiency Multistage Plasma Thruster, or HEMPT, has promising lifetime capabilities due to its plasma confinement system. However, the permanent magnet system that offers this and other benefits also creates a hollow plume, where ions are accelerated at angles rather than up the thruster centerline, causing a dip in ion current along the centerline. A laboratory model, built at JPL, was run at Cal Poly to characterize this plume shape and implement a shield to restore a conical shape to the plume. A similar solution was used on a different type of thruster, a cylindrical hall thruster, at Princeton with excellent results. A shield was designed to shunt the magnetic field outside the thruster, where the Princeton experiments have identified a radial magnetic field as the cause for this hollow plume. The thruster was run with and without the shield, taking measurements of the ion current in the plume using a linear probe drive. The shield fixed the plume shape, increasing centerline current by 48%, however it also had detrimental effects on thruster performance, causing a decrease in thrust, specific impulse, and cut the total efficiency in half. The shield design was reexamined and a new design has been suggested for future testing of the HEMPT to restore performance while still fixing the plume shape.

For as long as humans have waged war, they have distinguished between combatant persons that are liable to attack, and protected persons that should enjoy immunity from attack. And for just as long, combatants have exploited such protected persons as "human shields." They have moved protected persons to military targets, and military targets to protected persons with designs as grand as thwarting the outbreak of war itself, and as narrow as deterring attacks within war. This dissertation explores two sets of questions about these strategies and tactics of "interposition," as I call them, at the intersection of international relations, law, and ethics. First: Whence the power of "human shields?" When and how can belligerents, somewhat paradoxically, find safety in exposure with unarmed persons? Under what conditions can noncombatants exposed at flanks, for instance, deny superiorly positioned ambushers, and captives tied to warehouses deny fleets of aircraft? Second: How do we evaluate harm to people deliberately placed in harm's way? And to what extent are our judgments consistent with prevailing prescriptive models from international law and ethics? In this dissertation, I argue that interposition leverages a peculiar kind of threat. And I attribute the force of this threat to its peculiarities, integrating theory from psychology, anthropology, sociology and evidence from detailed case studies, interviews with military commanders, lawyers and soldiers, and accounts from tens of conflicts across the centuries culled from chronicles, archives, and memoirs. The threat is of killing, of directly and foreseeably harming others, of being identified with killing, of being held liable for killing, of authorizing outrage, massacre and scandal. The threat is distinct because it leverages not a hesitancy to incur damage, which is well documented in the conflict literature, but to inflict damage. And it is under some conditions sufficient to deter and compel even the strongest armies to yield and desist. Moreover, I present suggestive experimental evidence demonstrating some degree of conformity between lay intuitions and prevailing international legal and ethical prescriptions on proportionality in war. Lay respondents to a survey-embedded conjoint experiment balanced military value and collateral damage in ways prescribed by mainstream prescriptive models from international law and ethics. In particular, subjects weighed harm to bystanders and involuntary shields the same, but discounted harm to voluntary shields. In sum, the dissertation illuminates prevalent but poorly understood patterns of conflict behavior, and sheds light on understudied aspects of moral and legal judgment about harm in war.