Coastline changes and sedimentation related with the opening of an artificial channel: the Valo Grande Delta, SE Brazil

The role played by human activity in coastline changes indicates a general tendency of retreating coasts, especially deltaic environments, as a result of the recent trend of sea level rise as well as the blockage of the transfer of sediments towards the coast, especially due to the construction of dams. This is particularly important in deltaic environments which have been suffering a dramatic loss of area in the last decades. In contrast, in this paper, we report the origin and evolution of an anthropogenic delta, the Valo Grande delta, on the south-eastern Brazilian coast, whose origin is related to the opening of an artificial channel and the diversion of the main flow of the Ribeira de Iguape River. The methodology included the analysis of coastline changes, bathy metry and coring, which were used to determine the sedimentation rates and grain-size changes over time. The results allowed us to recognize the different facies of the anthropogenic delta and establish its lateral and vertical depositional trends. Despite not being very frequent, anthropogenic deltas represent a favorable environment for the record of natural and anthropogenic changes in historical times and, thus, deserve more attention from researchers of different subjects.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) [06/04344-2]info:eu-repo/semantics/publishedVersio

Wearable Biomonitoring Platform for the Assessment of Stress and its Impact on Cognitive Performance of Firefighters: An Experimental Study

Background: Stress is a complex process with an impact on health and performance. The use of wearable sensor-based monitoring systems offers interesting opportunities for advanced health care solutions for stress analysis. Considering the stressful nature of firefighting and its importance for the community’s safety, this study was conducted for firefighters. Objectives: A biomonitoring platform was designed, integrating different biomedical systems to enable the acquisition of real time Electrocardiogram (ECG), computation of linear Heart Rate Variability (HRV) features and collection of perceived stress levels. This platform was tested using an experimental protocol, designed to understand the effect of stress on firefighter’s cognitive performance, and whether this effect is related to the autonomic response to stress. Method: The Trier Social Stress Test (TSST) was used as a testing platform along with a 2-Choice Reaction Time Task. Linear HRV features from the participants were acquired using an wearable ECG. Self-reports were used to assess perceived stress levels. Results: The TSST produced significant changes in some HRV parameters (AVNN, SDNN and LF/HF) and subjective measures of stress, which recovered after the stress task. Although these short-term changes in HRV showed a tendency to normalize, an impairment on cognitive performance was found after performing the stress event. Conclusion: Current findings suggested that stress compromised cognitive performance and caused a measurable change in autonomic balance. Our wearable biomonitoring platform proved to be a useful tool for stress assessment and quantification. Future studies will implement this biomonitoring platform for the analysis of stress in ecological settings

Detrital carbonate sedimentation of the Rocas Atoll, South Atlantic

Located 266 km offshore Brazilian coast, Rocas Reef complex is the only atoll in the South Atlantic. Two scientific expeditions carried out detailed sedimentological studies of the complex. Sand texture was dominant in the sedimentary environment, although other textures such as gravel, sandy gravel and gravelly sand, were also observed. Mean size ranged from fine sand to coarse sand (-1.23 to 2.34ø), with an average value of 0.69ø (sand fraction), which from a geological perspective represents a high-energy environment. The values of mean size varied in the different geomorphologic compartments, a response to variable hydrodynamics on the reef. Sorting ranged from very well sorted to poorly sorted, with a mean value of 0.97ø (moderately sorted). The values of mean size and sorting are directly proportional (i.e. the larger the grain size, the better the sorting), a fact that might be controlled by the decreasing of organism diversity that contributes to the sedimentary environment as the mean size of the particles increase. Skewness parameter was used to correlate positive values to depositional environments. The Kurtosis parameter showed little relevance in this study. The sedimentary particles analyzed are exclusively composed of biogenic grains. In total eleven major groups were described, coralline algae being the most unusual

Heated flint TL-dating for Gruta da Oliveira (Portugal): dosimetric challenges and comparison of chronometric data

The Mousterian stratigraphy of Gruta da Oliveira (Torres Novas, Portugal) contains one of the latest occupations by Neanderthals on the Iberian Peninsula. Thermoluminescence (TL) dates on heated flints were obtained for layers 13 and 14, and compared with the radiocarbon (charcoal and burnt bone) and U/ Th (secondary carbonates) dating results available for those layers and the succession as a whole. As the internal dose rates are very low, the TL age estimates are very dependent on the external dose rates, which show significant variation, including indications of spatial patterning. Through close inspection of the radiation geometries of samples and dosemeters, the appropriate gamma dosimetry is identified and the weighted mean TL ages (1-s) calculated accordingly are 55 7 ka for layer 13 and 77 8 ka for layer 14. These ages are stratigraphically consistent with the radiocarbon chronology for layers 9e11 and with the termini ante and post quem provided by U-series dating for the beginning and end of the accumulation of the deposits. The TL results corroborate that all radiocarbon dates below layer 11 are minimum ages only and, given the constraints derived from the proxy data available, place layer 13 and 14 post MIS 5. Sample as well as dosemeter numbers are low at Gruta da Oliveira, which limits the precision of TLdating of a prehistoric human activity. Further refinement of the chronostratigraphy will be based on Useries dating of non-human-related, interstratified secondary carbonates.info:eu-repo/semantics/publishedVersio

1as. Jornadas de jovens investigadores da Escola Superior Agrária do Instituto Politécnico de Bragança

As I Jornadas de Jovens Investigadores da Escola Superior Agrária do Instituto Politécnico de Bragança são uma iniciativa da Direcção da Escola e das Comissões Científicas dos Mestrados. Com a realização do evento pretende-se que os estudantes apresentem publicamente os seus trabalhos de investigação conducentes à Dissertação, Trabalho de Projecto ou Estágio, realizados no âmbito dos mestrados, expondo-os à apreciação crítica dos colegas e da comunidade científica do IPB. As I Jornadas de Jovens Investigadores visam ainda estimular os estudantes que frequentam a parte curricular dos mestrados a desenvolverem e concluírem as suas teses, bem como dar uma visão geral do trabalho de investigação que se faz na Escola, facilitando a organização de equipas de trabalho multidisciplinares. A Direcção da ESA congratula-se pela significativa adesão dos alunos de mestrado ao evento e aproveita para agradecer os trabalhos recebidos. A realização das I Jornadas de Jovens Investigadores da Escola Superior Agrária do Instituto Politécnico de Bragança só foi possível graças ao empenho de uma vasta e diversificada equipa. Assim, a todos os membros da Comissão Organizadora, moderadores, palestrantes e co-autores dos trabalhos endereçamos os nossos sinceros agradecimentos