120 research outputs found

    An interdisciplinary investigation of a recent submarine mass transport deposit at the continental margin off Uruguay

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    Assessing frequency and extent of mass movement at continental margins is crucial to evaluate risks for offshore constructions and coastal areas. A multidisciplinary approach including geophysical, sedimentological, geotechnical, and geochemical methods was applied to investigate multistage mass transport deposits (MTDs) off Uruguay, on top of which no surficial hemipelagic drape was detected based on echosounder data. Nonsteady state pore water conditions are evidenced by a distinct gradient change in the sulfate (SO42−) profile at 2.8 m depth. A sharp sedimentological contact at 2.43 m coincides with an abrupt downward increase in shear strength from ∼10 to >20 kPa. This boundary is interpreted as a paleosurface (and top of an older MTD) that has recently been covered by a sediment package during a younger landslide event. This youngest MTD supposedly originated from an upslope position and carried its initial pore water signature downward. The kink in the SO42− profile ∼35 cm below the sedimentological and geotechnical contact indicates that bioirrigation affected the paleosurface before deposition of the youngest MTD. Based on modeling of the diffusive re‐equilibration of SO42− the age of the most recent MTD is estimated to be <30 years. The mass movement was possibly related to an earthquake in 1988 (∼70 km southwest of the core location). Probabilistic slope stability back analysis of general landslide structures in the study area reveals that slope failure initiation requires additional ground accelerations. Therefore, we consider the earthquake as a reasonable trigger if additional weakening processes (e.g., erosion by previous retrogressive failure events or excess pore pressures) preconditioned the slope for failure. Our study reveals the necessity of multidisciplinary approaches to accurately recognize and date recent slope failures in complex settings such as the investigated area

    Inorganic and organic geochemical fingerprinting of sediment sources and ocean circulation on a complex continental margin (São Paulo Bight, Brazil)

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    In this study, we use inorganic (metal) and organic (bulk and molecular) markers in sediment samples of the south-eastern Brazilian margin to investigate the response of geochemical fingerprints to the complex hydrodynamic processes present in the area. Results indicate the potential of export of terrigenous siliciclastic and organic constituents to the upper slope, even in an area with limited fluvial supply. Metal contents and especially the ln(Ti = Al) and ln(Fe = K) ratios make it possible to recognise the extension of shelf sediments toward the upper slope. Potassium, here expressedas ln(K = Sc) and ln(K = Al) ratios used as proxies of illite–kaolinite variations, proved to be an important parameter, especially because it allowed us to decipher the imprint of the northward flow of the Intermediate Western Boundary Current (IWBC) in comparison to the southward flows of the Brazil Current (BC) and Deep Western Boundary Current (DWBC). Using organic matter analyses, we were able to evaluate the extent of terrestrial contributions to the outer shelf and slope, even without the presence of significant fluvial input. In addition, molecular markers signify a slight increase in the input of C4-derived plants to the slope sediments, transported from distant areas by the main alongshore boundary currents, indicating that the terrestrial fraction of the organic matter deposited on the slope has a distinct origin when compared to shelf sediments

    Oceanographic processes and products around the Iberian margin: a new multidisciplinary approach

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    Our understanding of the role of bottom currents and associated oceanographic processes (e.g, overflows, barotropic tidal currents) including intermittent processes (e.g, vertical eddies, deep sea storms, horizontal vortices, internal waves and tsunamis) is rapidly evolving. Many deep-water processes remain poorly understood due to limited direct observations, but may generate significant depositional and erosional features on both short-and long-term time scales. This paper describes these oceanographic processes and examines their potential role in the sedimentary features around the Iberian margin. The paper explores the implications of the processes studied, given their secondary role relative to other factors such as mass-transport and turbiditic processes. An integrated interpretation of these oceanographic processes requires an understanding of contourites, sea-floor features, their spatial and temporal evolution, and the near-bottom flows that form them. Given their complex, three-dimensional and temporally-variable nature, integration of these processes into sedimentary, oceanographic and climatological frameworks will require a multidisciplinary approach that includes Geology, Physical Oceanography, Paleoceanography and Benthic Biology. This approach will synthesize oceanographic data, seafloor morphology, sediments and seismic images to improve our knowledge of permanent and intermittent processes around Iberia, and evaluate their conceptual and regional role in the sedimentary evolution of the margin. © 2015, Instituto Geologico y Minero de Espana. All rights reservedEl conocimiento del papel de las corrientes de fondo y los procesos oceanográficos asociados (overflows, corrientes de marea barotrópicas, etc), incluyendo procesos intermitentes (eddies, tormentas profundas, ondas internas, tsunamis, etc), está evolucionando rápidamente. Muchos de estos procesos son poco conocidos, en parte debido a que las observaciones directas son limitadas, si bien pueden generar importantes rasgos deposicionales y/o erosivos a escalas temporales de corto o largo periodo. Este artículo describe dichos procesos oceanográficos y examina su influencia en la presencia de rasgos sedimentarios alrededor del margen Ibérico. El trabajo discute las implicaciones de dichos procesos y el papel secundario que juegan en relación a otros factores tales como los procesos de transporte gravitacionales en masa y los turbidíticos. Para un mejor conocimiento de la sedimentación marina profunda, y en concreto de los sistemas contorníticos, se requiere de una interpretación de estos procesos oceanográficos, cuál es su evolución espacial y temporal, cómo afectan a las corrientes de fondo y cómo se ven afectados por la topografía submarina. Sin embargo, dada su complejidad y su variable naturaleza tridimensional y temporal, es necesario que estos procesos se integren en un marco sedimentológico, oceanográfico y climatológico con un enfoque multidisciplinar que incluyan la Geología, la Oceanografía Física, la Paleoceanografía y la Biología bentónica. Esta integración requiere de una mayor compilación de datos oceanográficos, de un mejor conocimiento de la morfología del fondo marino, y de una mejor caracterización de los sedimentos en ambientes profundos. Todo ello permitirá mejorar nuestro conocimiento de los procesos permanentes e intermitentes alrededor de Iberia y evaluar su verdadero efecto en la evolución sedimentaria delos márgenes continentales que le rodeanPostprint0,000

    Prevalence of age-related hearing loss in Europe: a review

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    Populations are becoming progressively older thus presenting symptoms of diminished organ function due to degenerative processes. These may be physiological or caused by additional factors damaging the organ. Presbyacusis refers to the physiological age-related changes of the peripheral and central auditory system leading to hearing impairment and difficulty understanding spoken language. In contrast to epidemiological data of other continents, the prevalence of age-related hearing loss (ARHL) in Europe is not well defined, due in part to the use of different classification systems. We performed a systematic literature review with the aim of gaining a picture of the prevalence of ARHL in Europe. The review included only population and epidemiological studies in English since 1970 with samples in European countries with subjects aged 60 years and above. Nineteen studies met our selection criteria and additional five studies reported self-reported hearing impairment. When these data were crudely averaged and interpolated, roughly 30% of men and 20% of women in Europe were found to have a hearing loss of 30 dB HL or more by age 70 years, and 55% of men and 45% of women by age 80 years. Apparent problems in comparing the available data were the heterogeneity of measures and cut-offs for grades of hearing impairment. Our systematic review of epidemiological data revealed more information gaps than information that would allow gaining a meaningful picture of prevalence of ARHL. The need for standardized procedures when collecting and reporting epidemiological data on hearing loss has become evident. Development of hearing loss over time in conjunction with the increase in life expectancy is a major factor determining strategies of detection and correction of ARHL. Thus, we recommend using the WHO classification of hearing loss strictly and including standard audiometric measures in population-based health surveys

    Lateral variability of ichnological content in muddy contourites: Weak bottom currents affecting organisms’ behavior

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    Although bioturbation is commonly recognized in contourites, only a few studies have analyzed the ichnological content of these deposits in detail. These studies have mainly focused on meso-scale bigradational sequence (a coarsening upward followed by a fining-upward sequence resulting from variations in current velocity). Here we present data from gravitational cores collected along the NW Iberian Margin showing systematic variation in ichnological content across proximal to distal depocenters within a large-scale elongated contourite drift. Data demonstrate that tracemakers’ behavior varies depending on the distance relative to the bottom current core. Trace fossils are already known to be a useful tool for studying of contouritic deposits and are even used as criterion for differentiating associated facies (e.g., turbidites, debrites), though not without controversy. We propose a mechanism by which the distance to the bottom current core exerts tangible influence on specific macro-benthic tracemaker communities in contourite deposits. This parameter itself reflects other bottom current features, such as hydrodynamic energy, grain size, nutrient transport, etc. Ichnological analysis can thus resolve cryptic features of contourite drift depositional settings.The contribution and research by JD was funded through the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 792314 (ICON-SE). The research of FJR-T was funded by project CGL2015-66835-P (Secretaría de Estado de Investigacion, Desarrollo e Innovacion, Spain), Research Group RNM-178 (Junta de Andalucía), and Scientific Excellence Unit UCE-2016- 05 (Universidad de Granada). AM’s research is funded by the I2C program of the Xunta de Galicia Postdoctoral programme (ED481B 2016/029-0). The research was conducted as part of “The Drifters Research Group” (RHUL) and “Ichnology and Palaeoenvironment Research Group” (UGR) programs

    Abordagem multifatorial do absenteísmo por doença em trabalhadores de enfermagem

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    OBJETIVO: Analisar fatores associados ao absenteísmo por doença autorreferido em trabalhadores de enfermagem. MÉTODOS: Estudo transversal com 1.509 trabalhadores de três hospitais públicos no município do Rio de Janeiro, RJ, em 2006. O absenteísmo foi classificado em três níveis: nenhum dia, poucos dias (um a nove dias) e muitos dias (>; 10 dias), a partir da resposta a uma pergunta do questionário de avaliação do índice de capacidade para o trabalho. As análises de regressão logística levaram em conta um modelo conceitual com base em determinantes distais (condições socioeconômicas), de níveis intermediários I (características ocupacionais) e II (características do estilo de vida), e proximais (doenças e condições de saúde). RESULTADOS: As frequências de absenteísmo por doença foram de 20,3% e 16,6% para poucos e muitos dias, respectivamente. Aqueles que referiram mais de um emprego, doenças osteomusculares e avaliaram sua saúde como ruim ou regular apresentaram chances mais elevadas de absenteísmo. Comparados aos enfermeiros, os auxiliares tiveram menor chance de referir poucos dias e os técnicos, maiores chances de apresentar muitos dias de ausência. Chances mais elevadas de referir muitos dias de ausência foram observadas entre os servidores públicos em relação aos contratados (OR = 3,12; IC95% 1,86;5,22) e entre os casados (OR = 1,73; IC95% 1,14;2,63) e separados, divorciados e viúvos (OR = 2,06; IC95% 1,27;3,35), comparados aos solteiros. CONCLUSÕES: Diferentes variáveis foram associadas às duas modalidades de absenteísmo, o que sugere sua determinação múltipla e complexa, relacionada a fatores de diversos níveis que não podem ser explicados apenas por problemas de saúde.OBJETIVO: Analizar factores asociados al ausentismo por enfermedad auto referida en trabajadores de enfermería. MÉTODOS: Estudio transversal con 1.509 trabajadores de tres hospitales públicos en Rio de Janeiro, Sureste de Brasil, en 2006. El ausentismo fue clasificado en tres niveles: ningún día, pocos días (uno a nueve días) y muchos días (>;10 días), a partir de la respuesta a una pregunta de cuestionario de evaluación del índice de capacidad para el trabajo. Los análisis de regresión logística tomaron en cuenta un modelo conceptual con base en determinantes distales (condiciones socioeconómicas), de nivel intermedio I (características ocupacionales) y II (características de estilo de vida) y, proximales (enfermedades y condiciones de salud). RESULTADOS: Las frecuencias de ausentismo por enfermedad fueron de 20,3% y 16,6% para pocos y muchos días, respectivamente. Aquellos que mencionaron más de un empleo, enfermedades osteomusculares y evaluaron su salud como mala o regular presentaron chances más elevados de ausentismo. En comparación con los enfermeros, los auxiliares tuvieron menor chance de relatar pocos días y los técnicos, mayores chances de presentar muchos días de ausencia. Chances mas elevados de mencionar muchos días de ausencia fueron observados entre los servidores públicos con relación a los contratados (OR=3,12; IC95% 1,86;5,22) y entre los casados (OR= 1,73; IC95% 1,14;2,63) y separados, divorciados y viudos (OR= 2,06; IC95% 1,27;3,35), en comparación con los solteros. CONCLUSIONES: Diferentes variables fueron asociadas con las dos modalidades de ausentismo, lo que sugiere su determinación múltiple y compleja, relacionada con factores de diversos niveles que no pueden ser explicados sólo por problemas de salud.OBJECTIVE: To analyze factors associated with self-reported sickness absenteeism among nursing workers. METHODS: Cross-sectional study with 1,509 workers from three public hospitals in the city of Rio de Janeiro (Southeastern Brazil) in 2006. Absenteeism was classified in three levels: no day, a few days (1-9 days) and many days (>; 10 days), based on the answer to a question of the work ability index questionnaire. The logistic regression analysis considered a conceptual model based on distal (socioeconomic status), intermediate I (occupational characteristics), intermediate II (lifestyle characteristics), and proximal (diseases and health conditions) determinants. RESULTS: The frequencies of sickness absenteeism were 20.3% and 16.6% for a few days and many days, respectively. Those who reported more than one job, musculoskeletal diseases and rated their health as poor or regular had higher odds of absenteeism. Compared to nurses, nursing assistants were less likely to mention a few days, and technicians were more likely to have many days of absence. Higher odds of mentioning many days of absence were observed among public servants, compared to contract workers (OR = 3.12; 95%CI 1.86;5.22), and among married (OR = 1.73; 95%CI 1.14;2.63) and separated, divorced and widowed individuals (OR = 2.06, 95%CI 1.27;3.35), compared to singles. CONCLUSIONS: Different variables were associated with the two forms of absenteeism, which suggests its multiple and complex determination related to factors from different levels that cannot be exclusively explained by health problems
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