Rock magnetism in soils of the Pampean plain. Buenos Aires province, Argentina. Linking climate and magnetic behaviour

Results of the study of Argiudolls in two localities (Zarate and Veronica) of the Pampean plain, Argentina, are presented in this contribution. This is a typical area covered by loess. The magnetic studies carried out allowed to determine the presence of detrital magnetite and titanomagnetite, as well as maghemite, pedogenic goethite and superparamagnetic particles (SP). In Veronica soils, a depletion of ferromagnetic minerals is recorded The dominant process in these soils has been the reductive loss of detrital magnetite and titanomagnetite. This is associated with a greater degree of evolution of the soil, which is determined by the concentration and type of detected clays. The higher clay concentration in these soils facilitated reducing conditions and a greater loss of detrital magnetic particles. The loss is reinforced under poor drainage conditions. In the poorly drained soil of Zarate, a concentration of magnetic particles is observed in the Bt horizon, which is associated with an illuviation process. The well drained soil of the same locality shows neoformation of SP particles. These particles would have an ephemeral life until a new wet period in the annual cycle occurs. Although some characteristics of the magnetic signal appear reinforced by the conditions of drainage, this aspect does not seem to be too significant, at least in the Pampean region with low topographic gradients.

Nurses’ perceptions of climate and environmental issues : a qualitative study

Aim: The aim of this study was to explore nurses' perceptions of climate and environmental issues and examine how nurses perceive their role in contributing to the process of sustainable development.  Background: Climate change and its implications for human health represent an increasingly important issue for the healthcare sector. According to the International Council of Nurses Code of Ethics, nurses have a responsibility to be involved and support climate change mitigation and adaptation to protect human health.  Design: This is a descriptive, explorative qualitative study.  Methods: Nurses (n=18) were recruited from hospitals, primary care and emergency medical services; eight participated in semi-structured, in-depth individual interviews and 10 participated in two focus groups. Data were collected from April-October 2013 in Sweden; interviews were transcribed verbatim and analysed using content analysis.  Results: Two main themes were identified from the interviews: (i) an incongruence between climate and environmental issues and nurses' daily work; and (ii) public health work is regarded as a health co-benefit of climate change mitigation. While being green is not the primary task in a lifesaving, hectic and economically challenging context, nurses' perceived their profession as entailing responsibility, opportunities and a sense of individual commitment to influence the environment in a positive direction.  Conclusions: This study argues there is a need for increased awareness of issues and methods that are crucial for the healthcare sector to respond to climate change. Efforts to develop interventions should explore how nurses should be able to contribute to the healthcare sector's preparedness for and contributions to sustainable development.

Climate and acute/subacute paracoccidioidomycosis in a hyper-endemic area in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Organizational safety climate and adherence to standard precautions among dentists

Objective: Check the perception of dentists about safety climate at work in relation to adherence to standard precautions.Methods: It is a quantitative, cross-sectional study conducted through the application of the Safety Climate Scale to a population of 224 dentists who worked in units of primary health care in six municipalities of Parana.Results: The total score of 3.43 (SD = 0.88) reveals that dentists have a poor perception of the incentives and organizational support for adopting standard precautions.Conclusion: Unsatisfactory safety climate, where the perception of dentists about safety in their work environment is deficient, demonstrating fragile management actions of support to safety, lack of a training program in occupational health and deficient feedback to favor the adoption of safe practices.

Influence of the meridional overturning circulation on tropical Atlantic climate and variability

The influence of the meridional overturning circulation on tropical Atlantic climate and variability has been investigated using the atmosphere-ocean coupled model Speedy-MICOM (Miami Isopycnic Coordinate Ocean Model). In the ocean model MICOM the strength of the meridional overturning cell can be regulated by specifying the lateral boundary conditions. In case of a collapse of the basinwide meridional overturning cell the SST response in the Atlantic is characterized by a dipole with a cooling in the North Atlantic and a warming in the tropical and South Atlantic. The cooling in the North Atlantic is due to the decrease in the strength of the western boundary currents, which reduces the northward advection of heat. The warming in the tropical Atlantic is caused by a reduced ventilation of water originating from the South Atlantic. This effect is most prominent in the eastern tropical Atlantic during boreal summer when the mixed layer attains its minimum depth. As a consequence the seasonal cycle as well as the interannual variability in SST is reduced. The characteristics of the cold tongue mode are changed: the variability in the eastern equatorial region is strongly reduced and the largest variability is now in the Benguela, Angola region. Because of the deepening of the equatorial thermocline, variations in the thermocline depth in the eastern tropical Atlantic no longer significantly affect the mixed layer temperature. The gradient mode remains unaltered. The warming of the tropical Atlantic enhances and shifts the Hadley circulation. Together with the cooling in the North Atlantic, this increases the strength of the subtropical jet and the baroclinicity over the North Atlantic.

The last mangroves of Marajo Island - Eastern Amazon: Impact of climate and/or relative sea-level changes

The dynamics, over the last 7500 years, of a mangrove at Marajo Island in northern Brazil were studied by pollen and sedimentary facies analyses using sediment cores. This island, located at the mouth of the Amazon River. is influenced by riverine inflow combined with tidal fluctuations of the equatorial Atlantic Ocean. Herbaceous vegetation intermingled with rainforest dominates the central area of the island, while varzea is the main vegetation type along the littoral. In particular, the modem northeastern coastal zone is covered by a mosaic of dense rainforest, herbaceous vegetation, mangroves, varzea, and restinga. The integration of pollen data and fades descriptions indicates a tidal mud flat colonized by mangroves in the interior of Marajo Island between similar to 7500 cal yr BP and similar to 3200 cal yr BP. During the late Holocene, mangroves retracted to a small area (100-700 m in width) along the northeastern coastal plain. Mangrove expansion during the early and mid Holocene was likely caused by the post-glacial sea-level rise which, combined with tectonic subsidence, led to a rise in tidal water salinity. Salinity must have further increased due to low river discharge resulting from increased aridity during the early and mid Holocene. The shrinking of the area covered by mangrove vegetation during the late Holocene was likely caused by the increase in river discharge during the late Holocene, which has maintained relatively low tidal water salinity in Marajo Island. Tidal water salinity is relatively higher in the northeastern part of the island than in others, due to the southeast-northwest trending current along the littoral. The mixing of marine and riverine freshwater inflows has provided a refuge for mangroves in this area. The increase in flow energy during the last century is related to landward sand migration, which explains the current retraction of mangroves. These changes may indicate an increased exposure to tidal influence driven by the relative sea-level rise, either associated with global fluctuations or tectonic subsidence, and/or by an increase in river water discharge. (C) 2012 Elsevier B.V. All rights reserved.

Tourism: low-cost airlines, climate and economic crisis

Programa de doctorado: Economía