Search

The development of sustainable shellfish aquaculture is highly dependent on the provision of reliable monitoring and predictive information on the occurrence of harmful algal blooms (HABs). The Portuguese HAB early warning system and shellfish closures presented here is a prototype, developed in the ASIMUTH project. It relies on weekly monitoring data composed of observations of HAB species and toxin concentrations within shellfish, and ocean circulation forecasts generated by an operational oceanographic model. The shellfish harvesting areas comprise coastal areas, estuaries + rías and coastal lagoons. The weekly bulletin characterizes the current shellfish closure situation and next week's forecasts for potentially impacted areas. The period analyzed ranged from 27 July 2013 to 17 March 2014, and describes the first skill assessment of the warning system. The forecast accuracy was evaluated, considering the number of forecasts that were verified to be correct the following week (85%) as well as the number of events not forecasted (false negatives, 12%) and those expected but did not occur (false positives, 3%). Variations were most visible in the first weeks of bulletin implementation and during autumn–winter months. The complementary use of field data, remote sensing and operational models led to more accurate predictions of blooms and range of the event. [ABSTRACT FROM AUTHOR]

Cohesive sediment dynamics in estuarine systems is a major issue in water quality and engineering problems. Numerical models can help to assess the complex dynamics of cohesive sediments, integrating the information collected in monitoring studies. Following a numerical approach we investigated the main factors that influence the cohesive sediment dynamics in an estuarine system composed of large mudflats (Tagus estuary, Portugal). After a spin up period of the bottom layer and considering the combined effect of waves and currents on the bottom shear stress, the dynamics of cohesive sediment during the fortnightly and daily erosion–sedimentation cycle was properly reproduced by the model. The results of cohesive suspended sediments were validated with data from sixteen monitoring stations located along the estuary and turbidity data measured by two multiparametric probes. The hydrodynamics were previously validated by harmonic analysis and with ADCP data. Although tidal currents are the major cause of cohesive sediment erosion, the results suggest that wind waves also play an important role. The simulated sediment mass involved in the fortnightly tidal cycle was in the same order of magnitude of the annual load from the rivers, as observed in previous studies based on field data. [ABSTRACT FROM AUTHOR]

Abstract: The relative impacts of tidal (neap, spring) and river discharge (including a flood event) forcing upon water and sediment circulation have been examined at the rock-bound Guadiana estuary. Near-bed and vertical profiles of current, salinity, turbidity, plus surface suspended sediment concentrations (SSC, at some stations only), were collected at the lower and central/upper estuary during tidal and fortnightly cycles. In addition, vertical salinity and turbidity profiles were collected around high and low water along the estuary. Tidal asymmetry produced faster currents on the ebb than on the flood, especially at the mouth. This pattern of seaward current dominance was enhanced with increasing river flow, due to horizontal advection that was confined within the narrow estuarine channel. The freshwater inputs and, at a degree less, the tidal range controlled the vertical mixing and stratification importance. Well-mixed (spring) and partially stratified (neap) conditions alternated during periods of low river flows, with significant intratidal variations induced by tidal straining (especially at the partially stratified estuary). Highly stratified conditions developed with increasing river discharge. Intratidal variability in the pycnocline depth and thickness resulted from current shear during the ebb. A salt wedge with tidal motion was observed at the lower estuary during the flood event. Depending on the intensity of turbulent mixing, the residual water circulation was dominantly controlled either by tidal asymmetry or gravitational circulation. The SSC was governed by cyclical local processes (resuspension, deposition, mixing, advection) driven by the neap-spring fluctuations in tidal current velocities. More, intratidal variability in stratification indicated the significance of tidal pumping at the partially and highly stratified estuary. The estuary turbidity maximum (ETM) was enhanced with increasing current velocities, and displaced downstream during periods of high river discharge. During the flood event, the ETM was expelled out of the estuary, and the SSC along the estuary was controlled by the sediment load from the drainage basin. Under these highly variable river flow conditions, our observations suggest that sand is exported to the nearshore over the long-term (>years). [Copyright &y& Elsevier]

The article studies acute ascending aortic dissection during pregnancy by researchers from Lisbon, Portugal. Although acute aortic dissection is a very rare case, it is a life-threatening emergency for both the mother and the fetus when it occurs, usually during the during the third trimester or puerperium. The condition necessitates a high index of clinical suspicion and an immediate multidisciplinary approach.

Introduction Rivastigmine is the only approved transdermal therapy for Alzheimer’s disease (AD). Reduced drug concentration variability compared to oral formulations may improve tolerability and optimize treatment effectiveness. Objectives The EXEPT study evaluated patient compliance, caregiver treatment preference and clinical outcomes in patients with mild to moderate AD initiating oral monotherapy (OM) or transdermal monotherapy (TM) with approved AD drugs. Methods EXEPT was a Portuguese observational multicentre trial that prospectively evaluated two cohorts of patients over 6 months (± 3 months): OM and TM, to which patients were assigned according to clinical criteria. Endpoints included patient compliance (evaluated by caregivers on a 0-10 scale), caregiver treatment preference and change in Mental State Examination (MMSE) and Neuropsychiatric Inventory domains scores. Results Eighteen investigators recruited 190 patients (63.5% female, mean age 75.99 [± 7.67]), of which 69.5% were initiated on TM. Patient compliance at study end was significantly higher in the TM group (9.4 versus 8.6 points, p<0.001); 95.3% of caregivers in TM cohort preferred this formulation. MMSE increased by a median of 2.0 points in both cohorts (p<0.001 versus baseline) but no difference was observed between groups (p=0.790). A higher proportion of patients on TM showed reduced agitation/aggression (30.9% versus 15.4%, p=0.035); after controlling for baseline MMSE and use of antipsychotics this difference remained significant (OR=2.795; p=0.030). Conclusions Transdermal rivastigmine was associated with higher compliance and caregiver preference and reduced agitation/aggression compared to OM. These findings may impact treatment decisions in AD patients with agitation and aggression and high caregiver burden. [ABSTRACT FROM AUTHOR]