Made available in DSpace on 2015-04-14T13:09:50Z (GMT). No. of bitstreams: 1 389728.pdf: 761156 bytes, checksum: 5bb03734c3b09a4ef16b93cf3d3d2546 (MD5) Previous issue date: 2007-03-23 / Segundo a Environmental Protection Agency (EPA) para um organismo ser selecionado para testes de toxicol?gicos ? necess?rio que se conhe?a: a distribui??o da esp?cie, sua localiza??o dentro da estrutura tr?fica, sua biologia, seus h?bitos nutricionais, sua fisiologia e por fim que sejam desenvolvidas t?cnicas de manuten??o de cultivo destes organismos em laborat?rio. Visando estas regras este trabalho foi dividido em quatro partes: No primeiro trabalho o amphipoda Hyalella curvispina foi coletado mensalmente de setembro 2003 a agosto 2005, na lagoa de Gentil, Tramanda?, Rio Grande do Sul, Brasil, e diferentes par?metros bioqu?micos e a lipoperoxida??o foram medidos. Os resultados sugerem que estes animais armazenam e degradam de forma sazonal as reservas energ?ticas investigadas. Durante o ver?o, o glicog?nio, os lip?dios totais, e os triglicer?deos foram armazenados, e utilizados durante o outono e o inverno. As f?meas armazenam prote?nas na primavera e usam no ver?o; enquanto que os machos armazenam as prote?nas na primavera e usam no inverno. Os n?veis do lipoperoxida??o durante o ano diferiram entre f?meas e machos. Estas varia??es podem estar relacionadas aos fatores bi?ticos (ex. per?odo reprodutivo) e aos fatores abi?ticos (ex. temperatura de ?gua, salinidade). No segundo trabalho foi comparado o efeito de varia??es sazonais no metabolismo energ?tico e nos n?veis de lipoperoxida??o de duas esp?cies simp?tricas de amphipoda, H. pleoacuta e H. castroi. Os animais foram coletados mensalmente de abril 2004 a mar?o 2006, no Vale das Trutas no munic?pio de S?o Jos? dos Ausentes. As an?lises estat?sticas revelaram diferen?as sazonais significativas na composi??o bioqu?mica, bem como, diferen?as entre sexos e esp?cies. Os fatores ambientais (ex., condi??es tr?ficas) e a reprodu??o pareceram ser os principais processos que influenciam os padr?es sazonais da composi??o bioqu?mica. No terceiro trabalho n?s comparamos varia??es no metabolismo energ?tico, nos n?veis de lipoperoxida??o e de par?metros reprodutivos de duas esp?cies de amphipoda, H. pleoacuta e H. curvispina mantido com duas dietas diferentes. Os animais foram coletados no inverno de 2004 e de 2005. No laborat?rio, os animais foram mantidos submersos em aqu?rios sob circunst?ncias controladas, alimentados ad libitum por 30 dias com dieta 1 (somente macr?fitas) ou dieta 2 (macr?fitas e ra??o). A an?lise estat?stica revelou diferen?as significativas na composi??o bioqu?mica entre os sexos e as dietas. A dieta 1 mimetizou a restri??o cal?rica, pois ocorreu uma deple??o do glicog?nio e das prote?nas totais nas duas esp?cies e sexos, este fato ? refor?ado por uma diminui??o nos n?veis do lipoperoxida??o. Nos amphipoda alimentados com a dieta 2, estes padr?es metab?licos foram revertidos. A dieta 2 forneceu informa??es valiosas a respeito da manuten??o adequada em laborat?rio para experimentos toxicol?gicos. As exig?ncias cal?ricas das esp?cies foram supridas somente com a dieta 2, que forneceu mais carboidratos, prote?nas e lip?dios. O quarto estudo investigou os efeitos do Carbofuran no metabolismo energ?tico, na lipoperoxida??o e na atividade do Na+/K+ATPase, e em par?metros reprodutivos nos amphipoda H. pleoacuta e H.curvispina. Os animais foram coletados no inverno de 2006. No laborat?rio, os animais foram mantidos submersos em aqu?rios sob circunst?ncias controladas e expostos ao Carbofuran numa dose de 5 ou 50μg/L por um per?odo de 7 dias. A an?lise estat?stica revelou que o pesticida induz diminui??es significativas no glicog?nio, nas prote?nas, nos lip?dios, nos triglicer?deos, e na Na+/K+ATPase, bem como, um aumento significativo nos n?veis de lipoperoxida??o. O estudo dos par?metros bioqu?micos parece ser promissor, a fim de avaliar e predizer os efeitos dos pesticidas em organismos do n?o-alvo. Os resultados sugerem tamb?m que os par?metros reprodutivos (forma??o dos pares, f?meas ov?geras e n?mero m?dio dos ovos) podem ser crit?rios sens?veis para avaliar efeitos ecotoxicol?gicos. Al?m disso, H. pleoacuta e H. curvispina s?o organismos apropriados para o uso em testes de toxicidade, e n?s sugerimos que s?o esp?cies sens?veis que poderiam ser usadas para monitorar estudos

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9 2 Abstract The object of the study was the soil crust, found on spoil tips after coal mining near Sokolov. Certain type of crusts were compared; non-biological, physico-chemical origin and biological crusts that are made up of algae, mosses and lichens. Individual samples of the crusts underwent the laboratory analysis - Water Drop Penetration Time, Sequencing Electron Microscopy, water infiltration, and field studies, where the measurements were taken by using the erosion pins, the surface of the crusts was evaluated and photographed stereoscopically. The results indicate that the the physical-chemical type of crusts show significantly greater erosion, while the biological crusts are less susceptible to erosion, this phenomenon is probably related to the mechanical firming of the surface. Keywords: Soil crust, Mining soil, Mining, Infiltration, Erosion

Made available in DSpace on 2015-04-14T14:51:38Z (GMT). No. of bitstreams: 1 391815.pdf: 353852 bytes, checksum: 1f18d70cef489dfb3cfe41e9e9478f45 (MD5) Previous issue date: 2007-04-13 / Foi comparado o efeito de diferentes dietas no metabolismo energ?tico, n?veis de lipoperoxida??o e atividade da enzima Na+/K+ATPase de Hyalella castroi assim como sob aspectos reprodutivos. Este crust?ceo vive em ambiente l?mnico no planalto do Rio Grande do Sul, Brasil. Os animais foram coletados durante os meses de outono de 2006 em S?o Jos? dos Ausentes. Em laborat?rio, os animais foram mantidos separados por sexo em aqu?rios sob condi??es controladas e alimentados ad libitum por 21 dias com diferentes dietas, sendo estas isocal?ricas. No final do per?odo experimental, os animais foram imediatamente congelados para determina??o dos diferentes par?metros bioqu?micos. Parte dos animais foram mantidos nas mesmas condi??es j? citadas, por?m em aqu?rios que permitiam o contato entre machos e f?meas. Para an?lise de alguns par?metros reprodutivos (n?mero de pareamentos, n?mero de f?meas ov?geras e n?mero de juvenis eclodidos). A an?lise estat?stica revelou diferen?a significativa na composi??o bioqu?mica ente os sexos e as dietas ao longo do cultivo experimental. As dietas foram capazes de alterar o padr?o bioqu?mico dos animais trazidos de campo e determinaram um alto percentual de sobreviv?ncia ao longo do per?odo de cultivo; contudo, n?o foram adequadas para permitirem o pleno sucesso reprodutivo principalmente em rela??o ao n?mero de f?meas ov?geras, a fertilidade e a qualidade dos ovos. Al?m disso, ambos os sexos mostraram respostas metab?licas e reprodutivas melhores quando alimentados com a dieta 1, a qual possui maior teor de carboidratos (43.19g/100g) e menor de prote?nas (30.88g/100g)

abstract: Biological soil crusts (biocrusts) are topsoil communities of organisms that contribute to soil fertility and erosion resistance in drylands. Anthropogenic disturbances can quickly damage these communities and their natural recovery can take decades. With the development of accelerated restoration strategies in mind, I studied physiological mechanisms controlling the establishment of cyanobacteria in biocrusts, since these photoautotrophs are not just the biocrust pioneer organisms, but also largely responsible for improving key soil attributes such as physical stability, nutrient content, water retention and albedo. I started by determining the cyanobacterial community composition of a variety of biocrust types from deserts in the Southwestern US. I then isolated a large number of cyanobacterial strains from these locations, pedigreed them based on their 16SrRNA gene sequences, and selective representatives that matched the most abundant cyanobacterial field populations. I then developed methodologies for large-scale growth of the selected isolates to produce location-specific and genetically autochthonous inoculum for restoration. I also developed and tested viable methodologies to physiologically harden this inoculum and improve its survival under harsh field conditions. My tests proved that in most cases good viability of the inoculum could be attained under field-like conditions. In parallel, I used molecular ecology approaches to show that the biocrust pioneer, Microcoleus vaginatus, shapes its surrounding heterotrophic microbiome, enriching for a compositionally-differentiated “cyanosphere” that concentrates the nitrogen-fixing function. I proposed that a mutualism based on carbon for nitrogen exchange between M. vaginatus and its cyanosphere creates a consortium that constitutes the true pioneer community enabling the colonization of nitrogen-poor, bare soils. Using the right mixture of photosynthetic and diazotrophic cultures will thus likely help in soil restoration. Additionally, using physiological assays and molecular meta-analyses, I demonstrated that the largest contributors to N2-fixation in late successional biocrusts (three genera of heterocystous cyanobacteria) partition their niche along temperature gradients, and that this can explain their geographic patterns of dominance within biocrusts worldwide. This finding can improve restoration strategies by incorporating climate-matched physiological types in inoculum formulations. In all, this dissertation resulted in the establishment of a comprehensive "cyanobacterial biocrust nursery", that includes a culture collection containing 101 strains, isolation and cultivation methods, inoculum design strategies as well as field conditioning protocols. It constitutes a new interdisciplinary application of microbiology in restoration ecology. / Dissertation/Thesis / Doctoral Dissertation Liberal Studies 2019

Following a wildfire, land management agencies act quickly to protect ecosystem services. We don't currently understand how post-wildfire managers make trade-off decisions in these tight timelines, or if these decisions reflect current science. Using Brunson’s (2014) social-ecological systems multi-scalar model, surveys assessed manager opinions about post-wildfire projects, perceptions of stakeholder opinions, and ability or willingness to consider new science results. Public surveys asked local citizens their opinions about post-wildfire projects. Manager perceptions were measured through semi-structured phone interviews (n = 8) and a structured online survey (n = 256). Public surveys were mailed to 1,000 (971 deliverable, n = 152 usable) residents in rural and urban Great Basin and Mojave Desert ZIP codes. We found coarse- and fine-scale social and political opinions were associated with all post-wildfire management decisions, often creating perceived barriers to project implementation. Conversely, local citizens were more supportive of projects than managers perceived them to be. While the majority of managers and citizens supported the concept of incorporating experimental research, managers were less able to consider more specific research incorporation into actual projects. Ecologically, biological soil crusts (BSC) are emerging as an important fine-scale component of semi-arid restorations. However, even when BSCs are assessed prior to a restoration plan, it is unclear how or if this knowledge has any impact. BSCs were evaluated both socially and ecologically: all manager surveys contained questions specifically related to BSC, and a pilot greenhouse study assessed a) if seed drilling simulations on different stages of BSC may affect restoration plant establishment and b) if BSC excluded the invasive species Bromus tectorum. Similar to other new science results, managers were unlikely to be able/willing to consider BSC status in post-wildfire projects. However, our results suggest the possibility that, even when lightly burned, seeding strategy may influence native plant establishment. In ideal greenhouse conditions, B. tectorum was able to establish readily on both burned and unburned BSC.

Xenoliths preserve evidence of magma-crust interactions in magmatic reservoirs and conduits. They reveal processes of partial melting of country rock, and disintegration into magma. Widespread evidence for frothy xenoliths in volcanic deposits exists, and these evidently indicate processes of gas liberation, bubble nucleation and bubble growth. This report focuses on textural analysis of frothy sandstone xenoliths from Krakatau in Indonesia, Cerro Negro in Nicaragua, Cerro Quemado in El Salvador and from Gran Canaria, Canary Islands, and involves attempts to experimentally reproduce xenolith textures. To achieve this, magmatic conditions acting upon country rock in volcanoes are simulated by subjecting sandstones to elevated temperature and pressure in closed system-autoclaves. Subsequent decompression imitates magma ascent following xenolith entrainment, and is largely responsible for the formation of frothy xenolith textures. The experiments show a range of successive features, such as partial melting, gas-pressure build up, bubble nucleation, growth and development of bubble networks. The experiments closely reproduced textures of natural xenoliths and help to assess the controlling P-T parameters that encourage efficient bubble growth. Conditions proved ideal between 850˚C and 870˚C and pressure release from 1 kbar. Such conditions limit bubble overprinting by secondary crystallization and melt infilling. Country rock lithology proved vital regarding gas pressure build-up and resulting bubble nucleation during decompression. In particular, increased water content and relict crystals in the melt produced appear to ease and promote gas liberation by enabling early and effective bubble nucleation. Moreover, experiments confirm a decisive role for bubble coalescence. These results attest to the great potential of country rock to develop interconnected bubble networks upon magma contact, exsolving large amounts of crustal volatiles into the magma. Volatile input involves a change in magma viscosity and thus an accompanied change in disruptive behaviour, and may hence be responsible for increased potential to cause explosive volcanic eruptions. Moreover, H2O and CO2 vapour are severe greenhouse gases, which seems to be added to the atmosphere from crustal rocks via recycling by volcanic activity, and may have yet underappreciated effects on Earth’s climate.

In the present thesis, “Hydrodynamics of Binary Bose-Einstein Condensates and Hydro-elasticity of the Inner Crust of Neutron Stars”, the hydrodynamic effects, instabilities and superfluid turbulence in binary immiscible ultracold gases, and hydro-elastic macroscopic coupled modes and microscopic structure of the inner layers of the crust of neutron stars, are studied. The ultracold gas dynamics can be realized in the laboratory. The excitation modes of the inner crust determine a number of observable properties such as elasticity, thermal properties and mass transport properties. Here we focus on expanding the details, rather than repeating the results presented in the published articles. In the part of the thesis related to atomic ultracold gases, we utilize the physical parameters in the experimentally realizable parameter region. We numerically simulate the coupled non-linear Schrödinger equations, and calculate observable quantities, such as phase and modulus of the order parameter, conditions needed for observation of the Rayleigh-Taylor instability and for turbulence generation. The numerical calculations are accompanied by analytical description of the processes. The dispersion relation for capillary-gravitational waves at the interface between two ultracold gases, is derived straightforwardly from the superfluid Lagrangian. The equations of motion for centre-of-mass of the superfluids are derived, and then used in our model of the quantum swapping of immiscible superfluids pressed by a strong external force. By numerical simulation, we find that the Kelvin-Helmholtz instability which occurs at the non-linear stage of the Rayleigh-Taylor instability, can generate quantum turbulence with peculiar properties. We find that two-dimensional superfluid systems with weak inter-component repulsion are different from previously studied strongly repulsive binary superfluids, because the quantum Kelvin-Helmholtz instability in weakly repulsive superfluids rolls up the whole interface forming a vortex bundle, similarly to dynamics of the shear fluid layers in the classical hydrodynamics. Production of vortex bundles favours the Kolmogorov spectrum of turbulence, and we find that the Kolmogorov scaling indeed is present in a freely decaying turbulence. In the part of the thesis related to neutron stars, we study the inner crust of neutron stars, where the fully ionized atomic nuclei coexist with a superfluid of neutrons. The interaction between superfluid neutrons and the crystallized Coulomb plasma is due to the interaction between density perturbations (interaction of the scalar type), and between the current - the non-dissipative entrainment effect (interaction of the vector type). We calculate velocities of the collective modes of the crystal coupled to superfluid neutrons. As an input we use the results of microscopic nuclear calculations in the framework of the compressible liquid drop model (the Lattimer and Swesty equation of state), and more recent effective Thomas-Fermi calculations with shell corrections (N. Chamel, and the Brussels theoretical nuclear physics group). Knowledge of velocities as functions of the matter density in the inner crust is important for calculation of a number of dynamic and transport properties. The heat transport properties of the inner crust are directly observable in accreting binary systems (low-mass x-ray binaries). The mass transport properties of the inner crust are directly linked to the rotational evolution, being a key physical ingredient of the pulsar glitch phenomenon. The elastic properties are related to the vibrational modes of the star, and to the breaking stress of the crust. In the second part of our work on neutron stars we investigate the microscopic structure of the inner crust treating the structure as an anisotropic crystal coupled to s-wave superfluid neutron liquid. As we analyse dynamics of the elementary excitations at higher wavenumbers (smaller scales), we reach the edge of the first Brillouin zone. The Lattimer-Swesty data is applicable for wavenumbers much smaller than the edge of the first Brillouin zone. We extrapolate the data through the whole first Brillouin zone to calculate the fastest growth rate of the unstable modes. The crucial step is to calculate the mode velocities in anisotropic crystal incorporating both the induced neutron-proton interactions, and the electron screening properties. We find that the combined influence of these two effects leads to softening of the longitudinal phonon of the lattice above about the Thomas-Fermi screening wavenumber of the electrons. The critical wavenumber when the frequency becomes purely imaginary is about  1/5 - 2/3  of the reciprocal lattice vector, thus validating our assumption. The imaginary mode frequency implies instability at finite wavenumbers. Our calculations suggest that the mode at the first Brillouin zone edge is the most unstable, and thus the structure experiences a displacive phase transition when the central ion of a unit cell of the body-cubic-centred lattice, is displaced to the cube face. Thus, the electronic structure of matter at densities above the neutron drip [1], is richer than previously appreciated, and new microscopic calculations of nuclear structure are necessary which take into account the high-wavenumber physics. Such calculations will provide crucial input to models interpreting the quasi-periodic oscillations in Soft Gamma Repeaters as magnetar x-ray flares, and to the theory of glitches of neutron stars. [1] The neutron drip density is ~3×1011 g cm-3.

This thesis discusses the results from the first multi-source and multi-streamer three-dimensional multichannel seismic experiment conducted over a mid-ocean ridge environment. Prestack time migration was applied to the dataset resulting in the most detailed reflection images of a spreading center and its flanks to date. The key products from this work are maps of crustal velocities, crustal thickness, and Moho transition zone (MTZ) reflection character for a section of the fast-spreading East Pacific Rise (EPR) from 9°37.5’N to 9°57’N, excluding the area from 9°40’N to 9°42’N where no data were collected. Moho reflections were imaged within ~92% of the study area. The derived average crustal thickness and average crustal velocity for the investigated ~880 km2 area are 5920±320 m and 6320±290 m/s, respectively. The average crustal thickness varies little from Pacific to Cocos plate suggesting mostly uniform crustal production in the last ~180 Ka. Detailed analysis of the crustal thickness and MTZ reflection character shows that the third-order segmentation is governed by melt extraction processes within the uppermost mantle while the fourth-order ridge segmentation arises from mid- to upper-crustal processes. This analysis also suggests that both the mechanism of lower-crustal accretion and the volume of melt delivered to the crust vary along the investigated section of the EPR. More efficient mantle melt extraction is inferred at latitudes from 9°42’N to 9°51.5’N, with greater proportion of the lower crust accreted from the AML than for the rest of the study area. Larger volume of melt is delivered to the crust from 9°37.5’N to 9°40’N than to the investigated crust further north. At some locations, the Moho reflections are for the first time unambiguously imaged below the AML away from any ridge discontinuity suggesting that the Moho is formed at zero age at least at some sections of the spreading centers. The first study of the melt content of mid-crustal off-axis magma lenses (OAML), done using amplitude variation with offset technique calibrated for a magmatic plumbing system, shows that these magma bodies contain 0 to 20% melt. This suggests that OAMLs likely contribute little to the overall crustal formation.