Sedimentology and age determinations on core PS2813-1

Die Rekonstruktion des Einflusses von Strömungen und glazialmarinen Prozessen auf das Sedimentationsgeschehen am Kontinentalhang der Antarktischen Halbinsel im westlichen Weddellmeer basiert auf sedimentologischen und geophysikalischen Daten eines Kolbenlotkerns. Der Sedimentkern wurde während des Fahrtabschnitts ANT-XIV/3 mit dem FS "Polarstern" aus einer mächtigen Levee-Struktur eines Rinnen-Rückensystems gewonnen. Es wurden sedimentologische sowie sedimentphysikalische Untersuchungen an dem Kernmaterial durchgeführt. Die texturellen Änderungen im Kern und die Variationen der gemessenen Parameter ermöglichen eine lithofazielle Gliederung und stratigraphische Einstufung der Sedimentabfolge. Die untersuchten Sedimente umfassen den Zeitraum der vier letzten Klimazyklen bis heute und repräsentieren die Ablagerungsbedingungen von mehr als 340 000 Jahren. Vier Faziestypen wurden unterschieden, die sowohl glaziale als auch interglaziale Ablagerungsräume charakterisieren. (1) Die überwiegend groblaminierten Sedimentabfolgen wurden der Laminitfazies zugeordnet. Unter glazialen Umweltbedingungen kam es infolge schwacher Bodenströmungen zur Ablagerung feinkörniger, laminierter, strömungsbetonter Sedimente. (2) Strukturlose, sehr homogene Sedimentabfolgen des Kems beschreiben einen weiteren, den Kaltzeiten zugeordneten, Faziestyp, der durch geringe Variationen in den Sedimenteigenschaften charakterisiert ist. (3) Kernabschnitte, die weitgehend strukturlos sind bzw. leichte Bioturbationen und relativ viel eistransportiertes Material aufweisen, wurden als IRD-Fazies bezeichnet. Sie repräsentiert den Übergang vom Glazial zum Interglazial, in dem sich das Schelfeis und die Meereisbeckung zurückzogen. In den Sedimenten kam es infolge der gesteigerten Kalbungsrate zur Anreicherung der Eisfracht. (4) Die relativ biogenreichen, hellen Ablagerungen wurden der interglazialzeitlichen Karbonatfazies zugeteilt. Der signifikant erhöhte Anteil planktischer Foraminiferen weist auf eine gesteigerte Bioproduktivität im Oberflächenwasser hin, die aus verstärkten jahreszeitlichen Schwankungen der Meereisbedeckung resultiert. Die betrachteten Sedimentationsprozesse, wie biologische Produktivität, Umlagerungsprozesse durch Meeresströmungen, gravitativer Sedimenttransport und Eistransport, sind das Abbild komplexer Wechselwirkungen aus Meeresspiegelschwankungen, Änderungen ozeanographischer Bedingungen und der Vereisungsdynamik. Das Sedimentationsgeschehen im Untersuchungsgebiet wurde folglich durch die Variationen der vorherrschenden Umweltbedingungen bestimmt. Im Glazial kam es unter einer geschlossenen Meereisbedeckung zur Ablagerung feinkörniger, geschichteter Sedimente. Vorwiegend Turbiditströmungen kontrollierten das Sedimentationsgeschehen innerhalb des betrachteten Rinnen-Rückensystems. Unter dem Einfluß der Coriolis-Kraft und wahrscheinlich einer Konturströmung wurden die suspendierten, feinkörnigen Partikel aus dem zentralen Bereich der Rinne verdriftet und über dem nördlichen Uferwall abgelagert. Höherenergetische gravitative Prozesse beeinflußten das Sedimentationsgeschehen episodisch und sind durch gut sortierte Ablagerungen mit erhöhten Gehalten im Mittel- bis Grobsiltbereich dokumentiert. Höhere Sedimentationsraten in den Glazialen trugen verstärkt zur Bildung des Uferwalls bei. Die Ablagerungen der ebenfalls glazialzeitlichen homogenen Fazies belegen unterschiedliche Ablagerungsbedingungen und eine Verschiebung der dominierenden Prozesse. Während des Übergangs vom Glazial zum Interglazial nahm die Bodenwasserbildungsrate durch das Aufschwimmen des Schelfeises zu, wodurch die Strömungsintensität gesteigert wurde. Eine verstärkte Eisbergaktivität wird durch die Anreichung des IRD-Materials dokumentiert. Während interglazialer Zeiten ermöglichten offen-marine Bedingungen im Südsommer eine leicht erhöhte biologische Produktivität, so daß der Ablagerungsraum durch die Sedimentation biogener Komponenten verstärkt beeinflußt wurde.

Sedimentologic and magnetic data of sediment cores on the western slope of the Mid-Atlantic Ridge

The relative paleointensity (RPI) method assumes that the intensity of post depositional remanent magnetization (PDRM) depends exclusively on the magnetic field strength and the concentration of the magnetic carriers. Sedimentary remanence is regarded as an equilibrium state between aligning geomagnetic and randomizing interparticle forces. Just how strong these mechanical and electrostatic forces are, depends on many petrophysical factors related to mineralogy, particle size and shape of the matrix constituents. We therefore test the hypothesis that variations in sediment lithology modulate RPI records. For 90 selected Late Quaternary sediment samples from the subtropical and subantarctic South Atlantic Ocean a combined paleomagnetic and sedimentological dataset was established. Misleading alterations of the magnetic mineral fraction were detected by a routine Fe/kappa test (Funk, J., von Dobeneck, T., Reitz, A., 2004. Integrated rock magnetic and geochemical quantification of redoxomorphic iron mineral diagenesis in Late Quaternary sediments from the Equatorial Atlantic. In: Wefer, G., Mulitza, S., Ratmeyer, V. (Eds.), The South Atlantic in the Late Quaternary: reconstruction of material budgets and current systems. Springer-Verlag, Berlin/Heidelberg/New York/Tokyo, pp. 239-262). Samples with any indication of suboxic magnetite dissolution were excluded from the dataset. The parameters under study include carbonate, opal and terrigenous content, grain size distribution and clay mineral composition. Their bi- and multivariate correlations with the RPI signal were statistically investigated using standard techniques and criteria. While several of the parameters did not yield significant results, clay grain size and chlorite correlate weakly and opal, illite and kaolinite correlate moderately to the NRM/ARM signal used here as a RPI measure. The most influential single sedimentological factor is the kaolinite/illite ratio with a Pearson's coefficient of 0.51 and 99.9% significance. A three-member regression model suggests that matrix effects can make up over 50% of the observed RPI dynamics.

Sedimentary record of the western Amundsen Sea Embayment after the last glacial maximum

Reliable dating of glaciomarine sediments deposited on the Antarctic shelf since the Last Glacial Maximum (LGM) is very challenging because of the general absence of calcareous (micro-) fossils and the recycling of fossil organic matter. As a consequence, radiocarbon (14C) ages of the acid-insoluble organic fraction (AIO) of the sediments bear uncertainties that are very difficult to quantify. In this paper we present the results of three different chronostratigraphic methods to date a sedimentary unit consisting of diatomaceous ooze and diatomaceous mud that was deposited following the last deglaciation at five core sites on the inner shelf in the western Amundsen Sea (West Antarctica). In three cores conventional 14C dating of the AIO in bulk sediment samples yielded age reversals down-core, but at all sites the AIO 14C ages obtained from diatomaceous ooze within the diatom-rich unit yielded similar uncorrected 14C ages ranging from 13,517±56 to 11,543±47 years before present (yr BP). Correction of these ages by subtracting the core-top ages, which are assumed to reflect present-day deposition (as indicated by 21044 Pb dating of the sediment surface at one core site), yielded ages between ca. 10,500 and 8,400 calibrated years before present (cal yr BP). Correction of the AIO ages of the diatomaceous ooze by only subtracting the marine reservoir effect (MRE) of 1,300 years indicated deposition of the diatom-rich sediments between 14,100 and 11,900 cal yr BP. Most of these ages are consistent with age constraints between 13.0 and 8.0 ka BP for the diatom-rich unit, which we obtained by correlating the relative palaeomagnetic intensity (RPI) records of three of the sediment cores with global and regional reference curves for palaeomagnetic intensity. As a third dating technique we applied conventional 53 radiocarbon dating of the AIO included in acid-cleaned diatom hard parts that were extracted from the diatomaceous ooze. This method yielded uncorrected 14C ages of only 5,111±38 and 5,106±38 yr BP, respectively. We reject these young ages, because they are likely to be overprinted by the adsorption of modern atmospheric carbon dioxide onto the surfaces of the extracted diatom hard parts prior to sample graphitisation and combustion for 14C dating. The deposition of the diatom-rich unit in the western Amundsen Sea suggests deglaciation of the inner shelf before ca. 13 ka BP. The deposition of diatomaceous oozes on other parts of the Antarctic shelf around the same time, however, seems to be coincidental rather than directly related.

Table 2 & Appendix A. Properties of operations injecting CO2 into saline aquifers

The experience from CO2 injection at pilot projects (Frio, Ketzin, Nagaoka, US Regional Partnerships) and existing commercial operations (Sleipner, Snøhvit, In Salah, acid-gas injection) demonstrates that CO2 geological storage in saline aquifers is technologically feasible. Monitoring and verification technologies have been tested and demonstrated to detect and track the CO2 plume in different subsurface geological environments. By the end of 2008, approximately 20 Mt of CO2 had been successfully injected into saline aquifers by existing operations. Currently, the highest injection rate and total storage volume for a single storage operation are approximately 1 Mt CO2/year and 25 Mt, respectively. If carbon capture and storage (CCS) is to be an effective option for decreasing greenhouse gas emissions, commercial-scale storage operations will require orders of magnitude larger storage capacity than accessed by the existing sites. As a result, new demonstration projects will need to develop and test injection strategies that consider multiple injection wells and the optimisation of the usage of storage space. To accelerate large-scale CCS deployment, demonstration projects should be selected that can be readily employed for commercial use; i.e. projects that fully integrate the capture, transport and storage processes at an industrial emissions source.

Microbiological quality of hamburgers sold in the streets of Cuiabá - MT, Brazil and vendor hygiene-awareness

This study evaluated the microbiological quality of hamburgers and the microbe community on the hands of vendors in Cuiabá, Mato Grosso, Brazil, in relation to vendors´ awareness as to what constitute acceptable food-handling practices as part of a broad-spectrum research programme on street foods in Brazil . Sale of the hamburger known as the 'baguncinha' is common and widespread in urban Cuiabá, Mato Grosso, Brazil. Food inspectors encounter various difficulties in carrying out inspections. One hundred and five hamburgers samples were evaluated using conventional methods including tests for facultative aerobic and/or anaerobic mesophytic bacteria, coliform counts at 45 °C, the coagulase test for Staphylococcus, Gram-staining for the presence of Bacillus cereus, Clostridium sulphite reductase and Salmonella spp. The hamburgers were categorized as unsuitable for human consumption in 31.4% of samples, with those testing positive for coliforms and Staphylococcus at unacceptably high levels by Brazilian standards. High levels of microbiological contamination were detected on the hands of the food handlers and mesophytic bacterial counts reached 1.8 × 10(4) CFU/hand. Interviews were carried out by means of questionnaires to evaluate levels of awareness as to acceptable food handling practices and it was found that 80,1% of vendors had never participated in any kind of training.

Hydrochemistry, mineralogy and sulphur isotope geochemistry of acid mine drainage at the Mt Morgan mine environment, Queensland, Australia

Mineralogical, hydrochemical and S isotope data were used to constrain hydrogeochemical processes that produce acid mine drainage from sulfidic waste at the historic Mount Morgan Au–Cu mine, and the factors controlling the concentration of SO4 and environmentally hazardous metals in the nearby Dee River in Queensland, Australia. Some highly contaminated acid waters, with metal contents up to hundreds of orders of magnitude greater than the Australia–New Zealand environmental standards, by-pass the water management system at the site and drain into the adjacent Dee River. Mine drainage precipitates at Mt. Morgan were classified into 4 major groups and were identified as hydrous sulfates and hydroxides of Fe and Al with various contents of other metals. These minerals contain adsorbed or mineralogically bound metals that are released into the water system after rainfall events. Sulfate in open pit water and collection sumps generally has a narrow range of S isotope compositions (δ34S = 1.8–3.7‰) that is comparable to the orebody sulfides and makes S isotopes useful for tracing SO4 back to its source. The higher δ34S values for No. 2 Mill Diesel sump may be attributed to a difference in the source. Dissolved SO4 in the river above the mine influence and 20 km downstream show distinctive heavier isotope compositions (δ34S = 5.4–6.8‰). The Dee River downstream of the mine is enriched in 34S (δ34S = 2.8–5.4‰) compared with mine drainage possibly as a result of bacterial SO4 reduction in the weir pools, and in the water bodies within the river channel. The SO4 and metals attenuate downstream by a combination of dilution with the receiving waters, SO4 reduction, and the precipitation of Fe and Al sulfates and hydroxides. It is suggested here that in subtropical Queensland, with distinct wet and dry seasons, temporary reducing environments in the river play an important role in S isotope systematics

Cenozoic continental weathering and its implications for the palaeoclimate: evidence from Ar-40/Ar-39 geochronology of supergene K-Mn oxides in Mt Tabor, central Queensland, Australia

One hundred and twenty-five mineral grains from 45 visually pure K-bearing Mn oxide (hollandite group) samples collected from weathering profiles in the Mt Tabor region of central Queensland, Australia, were analysed by the Ar-40/Ar-39 laser probe technique. These K-Mn oxides precipitated mainly through a process of cavity filling (direct precipitation from weathering solution), with botryoidal texture formed by micrometric mineral bands. Well-defined and reproducible plateau ages have been obtained for most samples, ranging from 27.2 +/- 0.8 to 6.8 +/- 0.5 Ma (2 sigma). Statistical analysis of the geochronological results by mixture modelling suggests an episodic mineral precipitation history, with two major peaks at 20.2 +/- 0.22 Ma and 16.5 +/- 0.17 Ma. The geochronological results, when combined with information on paragenetic relationships and mineralogical textures obtained from petrographic, scanning electron microscopy, and electron microprobe investigations, indicate that warm and humid palaeoclimatic conditions favourable to intense chemical weathering prevailed in central Queensland from late Oligocene to middle Miocene, particularly in the early Miocene. These results, in conjunction with previous and ongoing investigations in NW and eastern Queensland, suggest that most of Queensland was dominated by humid climates during the Miocene. (C) 2002 Elsevier Science BN. All rights reserved.

Comportamento de violência e fatores associados entre estudantes de Barra do Garças, MT

OBJETIVO: Estimar a prevalência de violência entre adolescentes e jovens adultos e identificar fatores associados. MÉTODOS: Estudo transversal com amostragem aleatória sistemática de 699 estudantes do ensino fundamental e médio da rede pública urbana de Barra do Garças, MT, em 2008. Questionário autopreenchível foi aplicado em sala de aula sem a presença do professor. O desfecho "comportamento violento" foi definido como (1) uso de arma de fogo ou branca, e/ou (2) agressões contra si e ou terceiros, e/ou (3) tentativa de suicídio. As variáveis independentes analisadas foram idade, gênero, condição socioeconômica, uso de álcool, uso de drogas psicoativas, atividade sexual e relacionamento com os pais. Foram realizadas análises univariadas e regressão múltipla ajustada para efeito de agregado. RESULTADOS: A prevalência de violência foi de 18,6%, variando segundo a idade: de 10,1% no grupo de dez e 11 anos; 20,2% dos 12 aos 19 anos; e 4,5% dos 20 e 21 anos. Os fatores associados ao comportamento de violência foram uso de álcool (RP = 2,51, IC95% 1,22;5,15), uso de drogas psicoativas (RP = 2,10, IC95%1,61;2,75), gênero masculino (RP = 1,63, IC95% 1,13;2,35) e relações insatisfatórias entre os pais (RP = 1,64, IC95% 1,25;2,15). CONCLUSÕES: Os resultados indicam alta prevalência de violência entre os adolescentes na faixa etária de 12 a 19 anos, sobretudo entre os usuários de álcool e drogas, do sexo masculino, de família cujos pais não possuem relações satisfatórias. Embora sem significância estatística no modelo final de regressão, a defasagem escolar e nível socioeconômico devem ser considerados em ações educativas de prevenção ao comportamento de violência entre estudantes.

Fluxo migratório de casos de malária em Cuiabá/MT, 1986

Foram estudadas 2.406 pessoas que procuraram a SUCAM/Cuiabá para diagnóstico e tratamento da malária. Destes, 1.151 tiveram lâminas positivas através da gota espessa: 720 P. vivax, 421 P. falciparum e 10 forma mista; 1.255 foram negativos à pesquisa de hematozoários. As entrevistas foram realizadas através de questionário padronizado onde procurou-se categorizar as pessoas conforme o sexo, idade, profissão, naturalidade, renda mensal, procedência e destino. Da análise efetuada vimos que os casos de malária originaram-se mais da micro-região Norte-Matogrossense para a Baixada Cuiabana (56,5%), colocando em risco toda a população desta micro-região, que encontra-se com borrificaçâo suspensa (DDT) na maioria das localidades. É também importante o fluxo de casos de malária do Estado de Rondônia (20,6%) e para os Estados da região Sul e Sudeste (4,4%) do país. Concluímos que medidas urgentes devam ser tomadas para a reformulação da campanha de controle da malária, planejando a intervenção nos aspectos sociais, políticos e econômicos.

Jornada Científica da Embrapa Agrossilvipastoril (4. : 2015 : Sinop, MT).

A IV Jornada Científica da Embrapa Agrossilvipastoril (Jcea) teve como objetivo promover o intercâmbio de conhecimento entre pesquisadores, estudantes e estagiários, colocando em discussão temas relevantes para pesquisa e inovação. Objetivou também valorizar alunos de graduação e pós-graduação, estimulando sua adesão e consolidando sua participação no meio científico e, por fim, divulgar os resultados obtidos. A IV Jcea aconteceu no período de 18 a 20 de agosto de 2015. Foram realizadas duas palestras e seções de apresentação de trabalho em formato de pôster e oral. A programação completa segue abaixo. Como em edições anteriores, foram mantidas atividades de interesse dos participantes, como a publicação e a apresentação de trabalhos técnico-científicos. Nesta edição, foram submetidos ao todo 36 resumos, destes, foram selecionados 18 para apresentação oral. O comitê selecionou os três melhores trabalhos e estes foram premiados com uma menção honrosa. Também foram aceitos para publicação uma revisão de literatura e um relato de caso. O Núcleo de Apoio a Projetos, o Comitê de Iniciação Científica e o Núcleo de Comunicação Organizacional foram responsáveis pela organização do evento.

Inquérito epidemiológico sobre características da população canina e felina de um bairro próximo à zona rural em Cuiabá-MT, visando o controle da raiva animal

Foram avaliados os questionários respondidos por 476 alunos, com idade entre 15 e 20 anos, de uma escola do bairro Pedra 90 em Cuiabá-MT, objetivando conhecer as características da população canina e felina daquele local. Dos 476 domicílios, em 371 (78%), foram registrados 513 cães e 307 gatos. Dos 513 cães, 289 (56,3%) eram machos e 224 (43,7%) fêmeas. Dos 307 gatos, 182 (59,3%) eram machos e 125 (40,7%) fêmeas. Os proprietários de 474 (92,4%) cães e 267 (86,9%) gatos afirmaram ter vacinado seus animais contra raiva.

Síndrome metabólica em hipertensos de Cuiabá - MT: prevalência e fatores associados

FUNDAMENTO: A síndrome metabólica (SM) é um agregado de fatores predisponentes para doenças cardiovasculares e diabete melito, cujas características epidemiológicas são insuficientemente conhecidas nos níveis regional e nacional. OBJETIVO: Estimar a prevalência de SM e fatores associados em uma amostra de hipertensos da área urbana de Cuiabá - MT. MÉTODOS: Estudo de corte transversal (maio a novembro de 2007) em amostra de 120 hipertensos (com 20 anos ou mais), pareados por gênero e selecionados por amostragem sistemática de uma população fonte de 567 hipertensos de Cuiabá. Todos os selecionados responderam a um inquérito em domicílio para obtenção de dados sócio-demográficos e hábitos de vida. Foram medidos: pressão arterial; índice de massa corpórea (IMC); circunferências da cintura e quadril; glicemia; insulinemia; lípides séricos; cálculo do índice de homeostase da resistência insulínica (HOMA); proteína C-reativa; ácido úrico e fibrinogênio. O critério para hipertensão adotado foi: média da PAS > 140mmHg e/ou PAD > 90mmHg, para síndrome metabólica segundo a I Diretriz Brasileira de Síndrome Metabólica e NCEP-ATP III. RESULTADOS: Foram analisados 120 hipertensos (60 mulheres), com média de idade de 58,3 ± 12,6 anos. Observou-se prevalência de SM de 70,8% (IC95% 61,8-78,8), com predomínio entre as mulheres (81,7% vs. 60,0%; p=0,009), sem diferenças entre adultos (71,4%) e idosos (70,2%). A análise de regressão múltipla revelou uma associação positiva entre a SM e o IMC > 25 kg/m², a resistência insulínica e algum antecedente familiar de hipertensão. CONCLUSÃO: Observou-se uma elevada prevalência de SM entre hipertensos de Cuiabá, associada significativamente ao IMC >25 kg/m², à resistência insulínica (Índice HOMA) e, em especial, a uma história familiar de hipertensão. Estes resultados sugerem o aprofundamento deste assunto através de novos estudos.