Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 192-211).

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 169-186).

Στόχος της εργασίας είναι να δείξει ότι ένα Σύστημα Σύγχρονης Λήψης και Απεικόνισης [ΣΣΛΑ] ή αλλιώς Microcomputer Based Laboratory [MBL] είναι ευνοϊκό για την μάθηση εννοιών των φυσικών επιστημών, μέσω δημιουργικής διερεύνησης και συνδυάζοντας τον πειραματισμό με αντικείμενα του πραγματικού κόσμου. Αυτό πραγματοποιείται με την παρατήρηση ενδείξεων, με τη λήψη μετρήσεων και με την καταγραφή των μεγεθών που εξελίσσονται, σε πραγματικό χρόνο στην οθόνη του υπολογιστή με τη χρήση αισθητήρων και κατάλληλου λογισμικού, προσφέροντας έτσι μια καλή σύνδεση μεταξύ των φαινομένων και πολλαπλών αναπαραστάσεων τους. / -

Made available in DSpace on 2014-06-11T19:32:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-02-17Bitstream added on 2014-06-13T19:43:40Z : No. of bitstreams: 1 murakami_to_dr_jabo.pdf: 283308 bytes, checksum: 16722a01d68e7e065fd2b025df90dded (MD5) / Os objetivos deste trabalho foram: estimar a prevalência da brucelose bovina nos municípios de Altinópolis e Santo Antonio da Alegria, SP; avaliar fatores de risco associados à taxa de prevalência; comparar as provas do antígeno acidificado tamponado (PAAT) e de soroaglutinação em placa (SAP) como testes de triagem no diagnóstico da brucelose bovina; e comparar as provas de fixação de complemento (FC) e 2-mercaptoetanol (ME) como testes confirmatórios. Foi obtida, aleatoriamente, uma amostra de 1.459 soros sangüíneos de bovinos de 132 rebanhos, que foram examinados pela PAAT e pela SAP. Os soros com reação nesses testes foram examinados também pelas provas de FC e ME. Foram também obtidas, por meio de um questionário, informações sobre características dos animais e dos rebanhos estudados. Constatou-se que 3,43% dos animais foram reagentes pela FC, e 16,67% dos rebanhos tinham pelo menos um animal reagente. Os fatores mais associados à prevalência foram sexo e idade dos animais e a introdução de animais no rebanho sem a exigência de exame de brucelose negativo. A PAAT apresentou melhor desempenho que a SAP como teste de triagem, e a FC apresentou melhor desempenho que a ME como teste confirmatório. / The purposes of this investigation were: to estimate de prevalence of bovine brucellosis in Altinópolis and Santo Antonio da Alegria, State of São Paulo, Brazil; to evaluate risk factors associated to the prevalence rate; to compare the rose Bengal and the plate agglutination serum tests for screening; and to compare the complement fixation and the mercaptoetanol as confirmatory tests. A sample of 1,459 sera from 132 herds were obtained at random and tested by the rose Bengal and the plate agglutination tests. Sera reacting at any of these tests were also tested by the complement fixation and by de mercaptoethanol test. Informations about the animais and the herds studied were also obtained. The results showed that 3.43% of the animals reacted to the complement fixation test, and 16.67% of the herds had at least one reacting animal. The factors more associated to the prevalence rate were sex and age of the animals and the introduction of animals in the herd without a negative test for brucellosis. The rose Bengal plate test peformed better than the plate agglutination test for screening, and the complement fixation test performed better than the mercaptoethanol test for the confirmatory diagnosis.

Orientador: Luís Antonio Mathias / Banca: Raul José Silva Girio / Banca: Sonia Regina Pinheiro / Banca: Paulo Francisco Domingues / Banca: Samir Issa Samara / Resumo: Os objetivos deste trabalho foram: estimar a prevalência da brucelose bovina nos municípios de Altinópolis e Santo Antonio da Alegria, SP; avaliar fatores de risco associados à taxa de prevalência; comparar as provas do antígeno acidificado tamponado (PAAT) e de soroaglutinação em placa (SAP) como testes de triagem no diagnóstico da brucelose bovina; e comparar as provas de fixação de complemento (FC) e 2-mercaptoetanol (ME) como testes confirmatórios. Foi obtida, aleatoriamente, uma amostra de 1.459 soros sangüíneos de bovinos de 132 rebanhos, que foram examinados pela PAAT e pela SAP. Os soros com reação nesses testes foram examinados também pelas provas de FC e ME. Foram também obtidas, por meio de um questionário, informações sobre características dos animais e dos rebanhos estudados. Constatou-se que 3,43% dos animais foram reagentes pela FC, e 16,67% dos rebanhos tinham pelo menos um animal reagente. Os fatores mais associados à prevalência foram sexo e idade dos animais e a introdução de animais no rebanho sem a exigência de exame de brucelose negativo. A PAAT apresentou melhor desempenho que a SAP como teste de triagem, e a FC apresentou melhor desempenho que a ME como teste confirmatório. / Abstract: The purposes of this investigation were: to estimate de prevalence of bovine brucellosis in Altinópolis and Santo Antonio da Alegria, State of São Paulo, Brazil; to evaluate risk factors associated to the prevalence rate; to compare the rose Bengal and the plate agglutination serum tests for screening; and to compare the complement fixation and the mercaptoetanol as confirmatory tests. A sample of 1,459 sera from 132 herds were obtained at random and tested by the rose Bengal and the plate agglutination tests. Sera reacting at any of these tests were also tested by the complement fixation and by de mercaptoethanol test. Informations about the animais and the herds studied were also obtained. The results showed that 3.43% of the animals reacted to the complement fixation test, and 16.67% of the herds had at least one reacting animal. The factors more associated to the prevalence rate were sex and age of the animals and the introduction of animals in the herd without a negative test for brucellosis. The rose Bengal plate test peformed better than the plate agglutination test for screening, and the complement fixation test performed better than the mercaptoethanol test for the confirmatory diagnosis. / Doutor

Type 2 diabetes mellitus (T2DM) is mainly caused by genetic modifications and inappropriate life styles. The complexity of T2DM has brought us challenges for a comprehensive understanding of altered metabolic pathways that contributing to the development of T2DM. Therefore, a comprehensive metabolic analysis is needed. To date, taking regular exercise is a common and effective therapeutic way known to antagonize the metabolic disorders of T2DM. However, the regulatory effects of exercise on T2DM or T2DM induced complications have not been clearly characterized. Here, we present the effect of physical activity on biochemical changes in diabetic db/db mice in plasma, urine, skeletal muscle and kidney samples. Based on liquid chromatography coupled with high resolution Orbitrap mass spectrometry (LC-MS) and gas chromatography coupled with mass spectrometry (GC-MS), two major approaches, untargeted and targeted metabolomics studies, have been developed to delineate metabolic signatures in various kinds of biofluid and tissue samples. Targeted quantification methods on acylcarnitines and acyl-CoA have been developed. Untargeted metabolomics analysis by GC-MS and LC-MS have also been developed to draw a more comprehensive view of the metabolic changes in response to T2DM and exercise on db/db diabetic mice. The transcript expressions of mRNA in pathways of interest have also been measured to confirm the hypothesis. Firstly, a targeted quantification method of acylcarnitines by using high resolution parallel reaction monitoring (PRM) on LC-MS platform has been developed. A total of 117 acylcarnitines were detected from plasma and urine samples. The application of targeted profiling of acylcarnitines in db/m+ control and db/db diabetic mice indicated incomplete amino acid and fatty acid oxidation in diabetic mice. Interestingly, the reduction of medium odd-numbered chain acylcarnitines in urine samples was firstly observed between db/m+ and db/db mice. The high resolution PRM method makes it possible to monitor the widespread metabolic changes of the acylcarnitines in response to stimuli. Besides, the accurate MS and MS/MS spectra data of the 117 acylcarnitines could be used as mass spectrometric resources for the identification of acylcarnitines. In addition to targeted metabolomics analysis, untargeted metabolomics profiling analysis in plasma samples indicated that db/db diabetic mice may be more susceptible to exercise for energy expenditure. Interestingly, all the results from plasma, skeletal muscle and kidney samples may demonstrate that physical activity could mitigate insulin resistance in T2DM mice through improving fatty acid β-oxidation (FAO) and eliminating overloaded intermediate which contribute to insulin resistance. Specifically, the results from kidney samples demonstrated that exercise exhibit beneficial effect in reducing hyperlipidemia, expression levels of inflammatory markers (TNFα, IL-6 and COX2) and fibrosis markers (Collagen 1), and alleviating diabetic nephropathy (DN) induced mesangial expansion in kidneys of diabetic mice. The results of metabolic changes in kidney of db/db mice revealed that the accumulation of acyl-CoA, phospholipids and hydroxylated acylcarnitines were substantially ameliorated by exercise, and the reduction of important enzymes CTP1α and Acadl in FAO were partially reversed. In addition, branched-chain amino acids (BCAA) metabolism which positively related to inflammation (TNFα) was down-regulated in DN mice by exercise. What’s more, the accumulation of uric acid, which contributes to inflammation and tubulointestitial fibrosis in kidney disease, together with its six precursors have also been substantially reduced. The results in kidney samples demonstrated that in addition to beneficial effect in alleviating lipotoxicity through improving FAO efficiency, exercise also ameliorated diabetic induced inflammation and fibrosis via promoting BCAA catabolism and accelerating the elimination of uric acid. Together, the mass spectrometry-based metabolomics study is a powerful tool to investigate the regulatory effect of exercise on complex metabolic diseases. The results may provide informative insights into the underlying the mechanism of exercise on T2DM and T2DM induced complications.

Descrevem-se os achados clínicos e patológicos da paratuberculose em uma criação intensiva de bovinos de leite no municí pio de Capela de Santana, RS. Os sinais clínicos foram observados em oito de um total de 345 bovinos, consistindo em diarréia crônica refratária aos tratamentos, emagrecimento progressivo e queda na produção de leite. As principais lesões macroscópicas, observadas nos oito animais necropsiados, incluíam intestino delgado com acentuado espessamento da parede e superfície mucosa de aspecto reticulado, semelhante às circunvoluções cerebrais, lesão essa perceptível, através da serosa. A luz intestinal estava preenchida com conteúdo fluido e de aspecto leitoso. Os vasos linfáticos do mesentério mostravam-se mais evidentes sendo que alguns tinham aspecto varicoso. Os linfonodos mesentéricos estavam aumentados de volume e, ao corte, fluía grande quantidade de líquido leitoso. Focos de mineralização foram observados na íntima das artérias, nas válvulas cardíacas e na serosa do rúmen. As principais lesões macroscópicas incluíam enterite, linfadenite e linfangite granulomatosa caracterizada por infiltrado inflamatório com macrófagos, células gigantes de Langhans que continham grande quantidade de bacilos álcool-ácido-resistentes. As lesões vasculares consistiam em degeneração e mineralização das túnicas í ntimas e média das artérias de grande calibre associada a proliferação de colágeno. Havia calcificação da serosa do rúmen atrofia hepatocelular difusa e hepatite granulomatosa multifocal. O M. avium subsp. paratuberculosis (Map) foi isolado em amostras de intestino e linfonodos de 8 vacas Holandesas (3,5%) com doença de Johne, dentre 229 amostras cultivadas provenientes de um rebanho leiteiro. Amostras inoculadas em HEYM com micobactina produziram colônias identificadas como Map, segundo as caracterí sticas fenotí picas próprias como: crescimento lento, coloração álcool-ácido-resistente (A.A.R.) e dependência a micobactina. O laboratório de Referência da OIE confirmou a amostra isolada. O M. avium subsp. paratuberculosis (Map) foi isolado em amostras de intestino e linfonodos de 8 vacas Holandesas (3,5%) com doença de Johne, dentre 229 amostras cultivadas provenientes de um rebanho leiteiro Amostras inoculadas em HEYM com micobactina produziram colônias identificadas como Map, segundo as caracterí sticas fenotí picas próprias como: crescimento lento, coloração álcool-ácido-resistente (A.A.R.) e dependência a micobactina. O laboratório de Referência da OIE confirmou a amostra isolada. Não houve isolamento do agente em 221 amostras intestinais quando processadas, após 2 anos de sua colheita. O teste de IDGA aplicado como “screening”, detectou 26 vacas (11,4%) positivas, dentre 228 animais testados e sacrificados em matadouro. O teste de ELISA adsorvido, utilizando o antí geno PPA-3 detectou 125 (39,8%) amostras positivas. O ELISA não adsorvido detectou mais 32 (10,1%) reagentes positivos, dentre os 314 bovinos testados. A prevalência da infecção causada pelo Map em 36 rebanhos leiteiros procedentes de 25 municí pios do Rio Grande do Sul foi estimada em 44,6% das 1316 amostras testadas. A infecção foi identificada em 35 (97,2%) dos 36 rebanhos testados e presentes em todos os municí pios incluí dos. A ocorrência da doença de Johne foi enfatizada, tanto a forma clí nica quanto a infecção subclí nica no Rio Grande do Sul, sugerindo a adoção de medidas de controle sejam aplicadas na proteção dos rebanhos leiteiros nacionais. / The clinical and pathological aspects of bovine paratuberculosis in a dairy herd in the county of Capela de Santana, Rio Grande do Sul, southern Brazil are described. Clinical signs in eight cows out 345 cattle included chronic diarrhea refractory to treatment, progressive emaciation and decreased milk production. Necropsy findings included severe and diffuse thickening of the mucosa of the small intestine with exaggerated reticular pattern, reflected in the serosal surface, similar to cerebral gyri. Intestinal loops were filled with whitish watery contents. The lymphatic vessels of the intestinal serosa and of the mesentery were thickened and tortuous. The mesenteric lymph nodes were enlarged and, on cut surface, there were oozing of milky fluid. Plaques of mineralization were evident in the intima of larger arteries, in the endocardium of the heart valves and in the ruminal serosa. There was also edema of abomasal folds and atrophy of caudate lobe of the liver. The main histopathological findings were granulomatous enteritis, lymphadenitis and lymphangitis. The inflammatory infiltrate was composed of macrophages, epithelioid cells and Langhan`s giant cells containing large numbers of acid-fast bacilli. Vascular lesions included degeneration, calcification and collagen proliferation of the intima and media of larger arteries. Other microscopic lesions included calcification of the ruminal serosa, diffuse hepatocellular atrophy and multifocal granulomatous hepatitis. M. avium subsp. paratuberculosis (Map) was isolated from intestines and lymph nodes samples obtained from 8 Holstein cows (3.5%) with Johne’s Disease among 229 inoculated samples from a unique dairy herd in Rio Grande do Sul State, South Brazil. Cultures on HEYM supplemented with mycobactin yielded colonies identified like Map by phenotypic properties: Slow growth, acid-fast stain and mycobactin dependency. OIE Reference Laboratory in Argentine confirmed the strain like Map. The attempts to isolate the agent from 221 intestinal samples processed after 2 years were unsuccessful. The AGIDT applied as a screening test detected 26 positive cows (11.4%) among 228 tested animals at slaughterhouse. The absorbed ELISA test using PPA-3 antigen detected 125 positive animals (39.8%) and 47 (14.9%) suspect samples among 314 animals tested. Nonabsorbed ELISA test detected more 32 (10.1%) positive animals and 18 (5.7%) suspect samples than absorbed ELISA test. The prevalence of infection caused by Map was estimated in 35 bovine dairy herds in Rio Grande do Sul State by absorbed ELISA using PPA-3 commercial antigen. The ELISA test identified 558 positive (44.6%) animals among 1316 samples tested. The infection was detected in 35 dairy herds (97.2%) among 36 tested and was present in all 25 countries performed. The infection by Map was disseminated in dairy herds in Rio Grande do Sul State. It’ s emphasized the occurrence of clinical and subclinical forms of Johne’ s disease in Rio Grande do Sul and should be necessity the adoption of control measures in the protection of National dairy herds.

Submitted by AMIRA AMARAL DO SIM null (amira@fc.unesp.br) on 2016-04-21T18:36:09Z No. of bitstreams: 1 Sim. A. A. dissertação.pdf: 2487505 bytes, checksum: 148a4856dd53c796419adc96a8ac947c (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-26T16:43:00Z (GMT) No. of bitstreams: 1 sim_aa_me_bauru.pdf: 2487505 bytes, checksum: 148a4856dd53c796419adc96a8ac947c (MD5) / Made available in DSpace on 2016-04-26T16:43:00Z (GMT). No. of bitstreams: 1 sim_aa_me_bauru.pdf: 2487505 bytes, checksum: 148a4856dd53c796419adc96a8ac947c (MD5) Previous issue date: 2016-02-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho foi desenvolvido com o objetivo de avaliar o impacto da utilização de um experimento remoto no processo de ensino e de aprendizagem em aulas de Física do Ensino Médio. Dessa forma, estudamos o impacto do experimento remoto em comparação com o mesmo experimento realizado presencialmente tentando entender em quais aspectos o experimento remoto pode contribuir com o ensino de conceitos de Física quando não se tem o acesso a experimentos presenciais. A análise dos dados de nossa investigação se dá a partir da ocorrência ou não de situações que facilitaram e/ou propiciaram a ocorrências de interações sociais úteis ao processo de ensino e de aprendizagem. A análise das interações foi feita mediante ao processo de construção de argumentos construídos pelos alunos. Os resultados mostram que o experimento remoto, assim como o presencial convencional é um facilitador do processo de interação social entre aluno e professor, sendo essa interação rica e significativa para a aprendizagem, assim, o laboratório remoto se mostra uma boa ferramenta de ensino. / This work was developed to evaluate the impact of using a remote experiment in the teaching and learning process in physics classes at high school. Thus, we studied the impact of remote experiment compared with the same experiment conducted in person trying to understand in which the remote experiment aspects can contribute to the teaching of physics concepts when you do not have access to classroom experiments. Data analysis of our investigation starts from the occurrence of situations that facilitated and/ or enabled the occurrence of social interactions useful to the process of teaching and learning. The analysis of the interactions was made by the process of building arguments built by students. The results show that the remote experiment, as well as the conventional classroom is a facilitator of the process of social interaction between student and teacher, and this rich and meaningful interaction for learning, so the remote laboratory caube cousidered a good teaching tool.

Descrevem-se os achados clínicos e patológicos da paratuberculose em uma criação intensiva de bovinos de leite no municí pio de Capela de Santana, RS. Os sinais clínicos foram observados em oito de um total de 345 bovinos, consistindo em diarréia crônica refratária aos tratamentos, emagrecimento progressivo e queda na produção de leite. As principais lesões macroscópicas, observadas nos oito animais necropsiados, incluíam intestino delgado com acentuado espessamento da parede e superfície mucosa de aspecto reticulado, semelhante às circunvoluções cerebrais, lesão essa perceptível, através da serosa. A luz intestinal estava preenchida com conteúdo fluido e de aspecto leitoso. Os vasos linfáticos do mesentério mostravam-se mais evidentes sendo que alguns tinham aspecto varicoso. Os linfonodos mesentéricos estavam aumentados de volume e, ao corte, fluía grande quantidade de líquido leitoso. Focos de mineralização foram observados na íntima das artérias, nas válvulas cardíacas e na serosa do rúmen. As principais lesões macroscópicas incluíam enterite, linfadenite e linfangite granulomatosa caracterizada por infiltrado inflamatório com macrófagos, células gigantes de Langhans que continham grande quantidade de bacilos álcool-ácido-resistentes. As lesões vasculares consistiam em degeneração e mineralização das túnicas í ntimas e média das artérias de grande calibre associada a proliferação de colágeno. Havia calcificação da serosa do rúmen atrofia hepatocelular difusa e hepatite granulomatosa multifocal. O M. avium subsp. paratuberculosis (Map) foi isolado em amostras de intestino e linfonodos de 8 vacas Holandesas (3,5%) com doença de Johne, dentre 229 amostras cultivadas provenientes de um rebanho leiteiro. Amostras inoculadas em HEYM com micobactina produziram colônias identificadas como Map, segundo as caracterí sticas fenotí picas próprias como: crescimento lento, coloração álcool-ácido-resistente (A.A.R.) e dependência a micobactina. O laboratório de Referência da OIE confirmou a amostra isolada. O M. avium subsp. paratuberculosis (Map) foi isolado em amostras de intestino e linfonodos de 8 vacas Holandesas (3,5%) com doença de Johne, dentre 229 amostras cultivadas provenientes de um rebanho leiteiro Amostras inoculadas em HEYM com micobactina produziram colônias identificadas como Map, segundo as caracterí sticas fenotí picas próprias como: crescimento lento, coloração álcool-ácido-resistente (A.A.R.) e dependência a micobactina. O laboratório de Referência da OIE confirmou a amostra isolada. Não houve isolamento do agente em 221 amostras intestinais quando processadas, após 2 anos de sua colheita. O teste de IDGA aplicado como “screening”, detectou 26 vacas (11,4%) positivas, dentre 228 animais testados e sacrificados em matadouro. O teste de ELISA adsorvido, utilizando o antí geno PPA-3 detectou 125 (39,8%) amostras positivas. O ELISA não adsorvido detectou mais 32 (10,1%) reagentes positivos, dentre os 314 bovinos testados. A prevalência da infecção causada pelo Map em 36 rebanhos leiteiros procedentes de 25 municí pios do Rio Grande do Sul foi estimada em 44,6% das 1316 amostras testadas. A infecção foi identificada em 35 (97,2%) dos 36 rebanhos testados e presentes em todos os municí pios incluí dos. A ocorrência da doença de Johne foi enfatizada, tanto a forma clí nica quanto a infecção subclí nica no Rio Grande do Sul, sugerindo a adoção de medidas de controle sejam aplicadas na proteção dos rebanhos leiteiros nacionais. / The clinical and pathological aspects of bovine paratuberculosis in a dairy herd in the county of Capela de Santana, Rio Grande do Sul, southern Brazil are described. Clinical signs in eight cows out 345 cattle included chronic diarrhea refractory to treatment, progressive emaciation and decreased milk production. Necropsy findings included severe and diffuse thickening of the mucosa of the small intestine with exaggerated reticular pattern, reflected in the serosal surface, similar to cerebral gyri. Intestinal loops were filled with whitish watery contents. The lymphatic vessels of the intestinal serosa and of the mesentery were thickened and tortuous. The mesenteric lymph nodes were enlarged and, on cut surface, there were oozing of milky fluid. Plaques of mineralization were evident in the intima of larger arteries, in the endocardium of the heart valves and in the ruminal serosa. There was also edema of abomasal folds and atrophy of caudate lobe of the liver. The main histopathological findings were granulomatous enteritis, lymphadenitis and lymphangitis. The inflammatory infiltrate was composed of macrophages, epithelioid cells and Langhan`s giant cells containing large numbers of acid-fast bacilli. Vascular lesions included degeneration, calcification and collagen proliferation of the intima and media of larger arteries. Other microscopic lesions included calcification of the ruminal serosa, diffuse hepatocellular atrophy and multifocal granulomatous hepatitis. M. avium subsp. paratuberculosis (Map) was isolated from intestines and lymph nodes samples obtained from 8 Holstein cows (3.5%) with Johne’s Disease among 229 inoculated samples from a unique dairy herd in Rio Grande do Sul State, South Brazil. Cultures on HEYM supplemented with mycobactin yielded colonies identified like Map by phenotypic properties: Slow growth, acid-fast stain and mycobactin dependency. OIE Reference Laboratory in Argentine confirmed the strain like Map. The attempts to isolate the agent from 221 intestinal samples processed after 2 years were unsuccessful. The AGIDT applied as a screening test detected 26 positive cows (11.4%) among 228 tested animals at slaughterhouse. The absorbed ELISA test using PPA-3 antigen detected 125 positive animals (39.8%) and 47 (14.9%) suspect samples among 314 animals tested. Nonabsorbed ELISA test detected more 32 (10.1%) positive animals and 18 (5.7%) suspect samples than absorbed ELISA test. The prevalence of infection caused by Map was estimated in 35 bovine dairy herds in Rio Grande do Sul State by absorbed ELISA using PPA-3 commercial antigen. The ELISA test identified 558 positive (44.6%) animals among 1316 samples tested. The infection was detected in 35 dairy herds (97.2%) among 36 tested and was present in all 25 countries performed. The infection by Map was disseminated in dairy herds in Rio Grande do Sul State. It’ s emphasized the occurrence of clinical and subclinical forms of Johne’ s disease in Rio Grande do Sul and should be necessity the adoption of control measures in the protection of National dairy herds.

abstract: Amorphous phases are detected over large regions of the Martian surface from orbit and in more localized deposits by rovers on the surface. Amorphous silicates can be primary or secondary in origin, both having formed through very different processes, so the unambiguous identification of these phases is important for understanding the geologic history of Mars. Secondary amorphous silicates are poorly understood and underrepresented in spectral libraries because they lack the long-range structural order that makes their crystalline counterparts identifiable in most analytical techniques. Fortunately, even amorphous materials have some degree of short-range order so that distinctions can be made with careful characterization. Two sets of laboratory experiments were used to produce and characterize amorphous weathering products under probable conditions for the Martian surface, and one global spectral analysis using thermal-infrared (TIR) data from the Thermal Emission Spectrometer (TES) instrument was used to constrain variations in amorphous silicates across the Martian surface. The first set of experiments altered crystalline and glassy basalt samples in an open system under strong (pH 1) and moderate (pH 3) acidic conditions. The second set of experiments simulated a current-day Martian weathering scenario involving transient liquid water where basalt glass weathering solutions, formed in circumneutral (pH ~5.5 and 7) conditions, were rapidly evaporated, precipitating amorphous silicates. The samples were characterized using visible and near-infrared (VNIR) spectroscopy, TIR spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). All experiments formed amorphous silicate phases that are new to spectral libraries. Moderately acidic alteration experiments produced no visible or spectral evidence of alteration products, whereas exposure of basalt glass to strongly acidic fluids produced silica-rich alteration layers that are spectrally consistent with VNIR and TIR spectra from the circum-polar region of Mars, indicating this region has undergone acidic weathering. Circum-netural pH basalt weathering solution precipitates are consistent with amorphous materials measured by rovers in soil and rock surface samples in Gale and Gusev Craters, suggesting transient water interactions over the last 3 billion years. Global spectral analyses determine that alteration conditions have varied across the Martian surface, and that alteration has been long lasting. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2016