Investigating marine shallow waters dynamics to explore the role of turbidity on ecological responses

The ecological tangible effect of the complex interaction between sediments and water column in shallow waters is represented by turbidity which is a common feature of most aquatic ecosystems: it varies both temporally and spatially; it can cover a huge area and persist for a long period or it can be very localized and temporary. Among many factors able to generate turbidity, wind generated wave action and water mass movements due to tides seem important in causing resuspension of sediments. Although there is much research spent in last decades on this topic and many models to explain the complexity of the wind-water-sediment interaction, some interactive aspects are too site specific and then still poor understood. On the other hand, this interaction involves many physical, chemical and trophic aspects like water flow velocity, turbulence, boundary layer thickness, environmental stresses and, in turn, resuspension, transport, and deposition of particulate matter, mechanical limits to size, larval dispersion, food availability. To get further knowledge on these aspects, we carried out in March 2007 a 5-day-experiment in a Mediterranean shallow area (The Stagnone di Marsala, Western Sicily) by collecting data on wind and water velocities, their directions and the contextual response of the water column in term of turbidity, chlorophyll-a and suspended solids (by ignition). To analyse the interaction, we proceeded step by step. Firstly, we studied data from the two current meters (an acoustic doppler velocimeter 40 ± 2 cm deep, and an electromagnetic current meter 20 ± 2 cm deep). From this data, the water column had the following features: i) during the big semidiurnal tidal transitional phase, the flow field followed a behaviour leading us to hypothesize a logarithmic layer defined by the law of the wall and to obtain friction velocity values with linear regression in good agreement with calculated ones with covariance and TKE method, while ii) during the small tidal transition and at high and low tides, a not-well defined gradient was present (i.e., the mean deviation of the direction of the two water velocities was more than 30° and the flow magnitude at 40 cm was less than that measured at 20 cm implying high values of turbulence intensity). The second step analysed data from multiprobe, ADV, meteorological station and considered turbidity (NTU) as proxy of food availability for consumers. NTU followed a one-day-period and the lower the turbidity, the higher the turbulence (both at 20 and 40 cm)

Autologous Hematopoietic Stem Cell Transplantation (AHSCT): Standard of Care for Relapsing–Remitting Multiple Sclerosis Patients

Abstract Autologous hematopoietic stem cell transplantation (AHSCT) has been used in the treatment of highly active multiple sclerosis (MS) for over two decades. It has been demonstrated to be highly efficacious in relapsing–remitting (RR) MS patients failing to respond to disease-modifying drugs (DMDs). AHSCT guarantees higher rates of no evidence of disease activity (NEDA) than those achieved with any other DMDs, but it is also associated with greater short-term risks which have limited its use. In the 2019 updated EBMT and ASBMT guidelines, which review the clinical evidence of AHSCT in MS, AHSCT indication for highly active RRMS has changed from “clinical option” to “standard of care”. On this basis, AHSCT must be proposed on equal footing with second-line DMDs to patients with highly active RRMS, instead of being considered as a last resort after failure of all available treatments. The decision-making process requires a close collaboration between transplant hematologists and neurologists and a full discussion of risk–benefit of AHSCT and alternative treatments. In this context, we propose a standardized protocol for decision-making and informed consent process

Organic enrichment can increase the impact of microplastics on meiofaunal assemblages in tropical beach systems

The cumulative impact of microplastic and organic enrichment is still largely unknown. Here, we investigated the microplastic contamination, the organic enrichment and their effects on meiofaunal distribution and diversity in two islands of the Maldivian archipelago: one more pristine, and another strongly anthropized. Field studies were coupled with manipulative experiments in which microplastic polymers were added to sediments from the non-anthropized island (i.e., without organic enrichment) to assess the relative effect of microplastic pollution on meiofauna assemblages. Our results reveal that the impact of microplastic contamination on meiofaunal abundance and taxa richness was more significant in the anthropized island, which was also characterized by a significant organic enrichment. Meiofauna exposed experimentally to microplastic contamination showed: i) the increased abundance of opportunistic nematodes and copepods and ii) a shift in the trophic structure, increasing relevance in epistrate-feeder nematodes. Based on all these results, we argue that the coexistence of chronic organic enrichment and microplastics can significantly increase the ecological impacts on meiofaunal assemblages. Since microplastic pollution in the oceans is predicted to increase in the next decades, its negative effects on benthic biodiversity and functioning of tropical ecosystems are expected to worsen especially when coupled with human-induced eutrophication. Urgent actions and management plans are needed to avoid the cumulative impact of microplastic and organic enrichment