Hydrodynamic forcing and sand permeability influence the distribution of anthropogenic microparticles in beach sediment

The distribution of anthropogenic microparticles (Mps), such as plastic and natural fibres used in textiles, in beach sediments was studied in a human-influenced pocket beach in Liguria (NW Mediterranean Sea). Information on environmental parameters such as rainfall, hydrodynamic characteristics and sediment texture was collected at the same time as the sediment samples. The Mps (416 +- 202 Mps kg-1 on average) were mainly fibres (57\u2013100%), while fragments and spheres showed irregular abundances linked to the draining action of waves on the beach. Uni- and multivariate statistical analyses highlighted that the different spatial and seasonal distribution of fibres primarily depended on the action of the waves that force seawater into the sand, rather than on sedimentation following depositional processes. Wave height and direction had a role in fibre distribution in the sand, as well as sediment permeability and sorting. The occurrence of short-term and spatially-localised hydrodynamic events such as rip currents were observed to influence the abundance of fibres, overlapping the seasonal sequences of beach accretion and erosion that is typical of the area and increasing fibre abundance by transporting those accumulated in the sediments of the submerged beach during winter

Macrofaunal assemblages in canyon and adjacent slope of the NW and Central Mediterranean systems

Macrofaunal assemblages were studied along bathymetric transects in six canyons and four adjacent open slopes of the Mediterranean Sea. The different areas investigated were located approximately along a longitudinal gradient at similar latitudes. Three regions were investigated: the Catalan (from 334 to 1887 m depth), the Ligurian (from 222 to 2005 m depth) and the South Adriatic margins (from 196 to 908 m depth). The analysis of the meso-scale distribution of assemblage structure and biomass showed significant differences among regions, which resulted in high values of \u3b4-diversity. Clear differences in trophic composition were also observed, and a decreasing pattern in the individual body size of macrofaunal organisms moving Eastward. These patterns were apparently linked to changes in food supply, whereas macrofaunal abundance and number of taxa showed a decrease pattern with increasing water depth. When the assemblage structure was compared between canyons and adjacent open slope, a very high \u3b2-diversity was observed, indicating that the bottom topography exerted a strong effect on the assemblage characteristics

The allochthonous material input in the trophodynamic system of the shelf sediments of the Gulf of Tigullio (Ligurian Sea, NW Mediterranean)

The organic allochthonous material input in the benthic system of a NW Mediterranean shelf area was studied using a three-pronged approach, focusing firstly on the evaluation of the sedimentary stable isotope ratios and organic matter (OM) composition, then on the OM recycling processes performed by the microbial organisms, and finally on the potential trophic relationships between the macrobenthic organisms. The highest allochthonous signal, indicating continental input, was observed within the 50-m isobath, while at the 80-m isobath the marine signal was higher, pointing to a rather low continental influence approximately 5 km from the shore. Heavier rainfall, often generating abrupt allochthonous inputs by river outfalls, led to a wider spread of fine sediment particles. Carbohydrates were the compounds that best represented the continental input and these compounds were associated with potential recycling activities by microbiota, pointing to the entry of these C-containing allochthonous materials into the microbial food web. The macrofaunal deposit-feeders used sedimentary OM characterised by a continental signature as a food source, although the isotopic ratios of the organisms also pointed to selective feeding on materials that had a marine signature, especially at our offshore sampling stations. Predators fed on deposit- or suspension-feeders, with a potential selection of the latter during the highest inputs of continental materials occurring in winter

El papel del acoplamiento pelágico-bentónico en la estructuración de las comunidades litorales bentónicas en la bahía de Terra Nova (Mar de Ross) y en el Estrecho de Magallanes

In Antarctic and peri-Antarctic regions, benthic communities are persistent in time and show high biomass and large numbers of individuals, mainly consisting of suspension and deposit feeders. In fact, apart from recruitment, the major factor structuring these communities is the high flow of organic matter from the pelagic domain to the bottom, representing an important energy source for the benthic organisms. The aim of this paper is to review, compile and compare the data from earlier investigations in Terra Nova Bay (Ross Sea) and the Straits of Magellan, in order to come to a more general conclusion about the role of the pelagic-benthic coupling in structuring littoral benthic communities in southern coastal areas. Few measurements of flux rates and the biochemical composition of the sinking particles occurring in Antarctic and peri-Antarctic shallow waters are available, but a compilation of our own data and others allows a comparison of these two systems. The different environmental conditions between Antarctica and the Straits of Magellan lead to differences in the origin of the particulate organic matter and in its biochemical composition, and consequently in the coupling between pelagic and benthic domains. At Terra Nova Bay the summer particulate matter shows a high labile fraction of a good food value: its flux has been evaluated at about 0.67 g m-2d-1. Conversely, the Straits of Magellan show multi-structured ecosystems where the quality and quantity of the organic matter flux towards the bottom change according to the local geomorphology and current dynamics. Moreover, the three-dimensional assemblages of suspension-feeders, so common in Antarctic shallow waters, seem to be absent in the Magellan area. In particular sponges, gorgonarians and bryozoans play a secondary role inside the Straits of Magellan, where polychaetes (60%) and molluscs (9-10%) are dominant on soft bottoms, and where they reach high values in density and biomass. Bivalves seem to play an important role in both regions: for instance, at Terra Nova Bay, the scallop Adamussium colbecki processes about 14 % of the total carbon flux, with an assimilation efficiency of 36 %. This scallop seems to be able to adapt its reproductive period and its trophic behaviour to the changes in the quality and quantity of the pelagic events. The pulsing trend of the vertical flux, which in a few weeks can reach the total annual input, produces significant changes in the physiology (growth, reproduction, spawning) and trophic behaviour of many benthic species, such as sponges and polychaetes. The study of the pelagic-benthic coupling could be essential in the evaluation of the trophic capacity and the environmental response around sites of sea-farming, which are an ever-growing activity in the Magellan area.En las regiones Antártica y periantártica, las comunidades bentónicas son persistentes en el tiempo y muestran altos valores de biomasa y número de individuos. Estas comunidades están constituídas, principalmente, por organismos suspensívoros y detritívoros. Aparte del reclutamiento, el factor más importante en estructurar estas comunidades es el flujo de materia orgánica desde la zona pelágica al bentos, lo que representa una importante fuente de energía para los organismos del fondo. No obstante la gran importancia de la producción primaria como suministro de alimento para las comunidades béntonicas litorales, la información sobre la tasa de flujo y la composición bioquímica del material que sedimenta es reducida. Muestreos rea lizados con trampas de sedimento han mostrado altos valores de flujo de materia orgánica caracterizado por una elevada presencia de paquetes fecales, particularmente importantes en el transporte de materia orgánica desde la zona fótica a las aguas profundas. En Bahía Terra Nova (Mar de Ross) la materia orgánica estival presenta una fracción lábil importante, un alto valor alimentario y un flujo que se evaluó en aproximadamente 0.67 g m-2d-1. Las diferentes condiciones ambientales de la Antártida y el Estrecho de Magallanes ocasionan diferencias en el origen y en la composición bioquímica de la materia orgánica particulada y, consecuentemente, en el acoplamiento entre los dominios pelágico y bentónico. El Estrecho de Magallanes, contrariamente a las observaciones hechas en la Antártida, muestra un sistema de flujo de materia orgánica hacia el fondo , debido a su geomorfología peculiar y a la dinámica de las corrientes. Por otra parte, los agrupamientos tridimensionales de suspensívoros, comunes en las aguas someras antárticas, parecen estar ausentes en el área del Estrecho de Magallanes. Particularmente esponjas, gorgonias y briozoos desempeñan un papel secundario en el interior del Estrecho de Magallanes, donde poliquetos (60%) y moluscos (9-10%) dominan en los fondos blandos, alcanzando altos valores de densidad y biomasa. Los bivalvos desempeñan un papel importante en ambas regiones: en la Bahía de Terra Nova, el pectínido Adamussium colbecki procesa aproximadamente el 14% del flujo total de carbono, con una eficiencia de asimilación del 36%. Este pectínido sería capaz de adaptar su periodo reproductivo y su estrategia trófica a los cambios en la calidad y la cantidad de materia orgánica. Los pulsos del flujo vertical, que en pocas semanas puede alcanzar el suministro total anual, producen cambios significativos en la fisiología (crecimiento, reproducción, freza) y en el comportamiento trófico de algunas especies bentónicas, como esponjas y poliquetos. Finalmente, el estudio del acoplamiento bentos-pélagos puede ser esencial en la evaluación de la capacidad trófica y la respuesta ambiental para la ubicación de zonas de cultivos marinos, actividad en continuo crecimiento en el área de Magallanes

Phytoplankton blooms during austral summer in the Ross Sea, Antarctica: Driving factors and trophic implications

During the austral summer of 2014, an oceanographic cruise was conducted in the Ross Sea in the framework of the RoME (Ross Sea Mesoscale Experiment) Project. Forty-three hydrological stations were sampled within three different areas: the northern Ross Sea (RoME 1), Terra Nova Bay (RoME 2), and the southern Ross Sea (RoME 3). The ecological and photophysiological characteristics of the phytoplankton were investigated (i.e., size structure, functional groups, PSII maximum quantum efficiency, photoprotective pigments), as related to hydrographic and chemical features. The aim was to identify the mechanisms that modulate phytoplankton blooms, and consequently, the fate of organic materials produced by the blooms. The observed biomass standing stocks were very high (e.g., integrated chlorophyll-a up to 371 mg m-2 in the top 100 m). Large differences in phytoplankton community composition, relative contribution of functional groups and photosynthetic parameters were observed among the three subsystems. The diatoms (in different physiological status) were the dominant taxa in RoME 1 and RoME 3; in RoME 1, a post-bloom phase was identified, whereas in RoME 3, an active phytoplankton bloom occurred. In RoME 2, diatoms co-occurred with Phaeocystis antarctica, but were vertically segregated by the upper mixed layer, with senescent diatoms dominating in the upper layer, and P. antarctica blooming in the deeper layer. The dominance of the phytoplankton micro-fraction over the whole area and the high Chl-a suggested the prevalence of non-grazed large cells, independent of the distribution of the two functional groups. These data emphasise the occurrence of significant temporal changes in the phytoplankton biomass in the Ross Sea during austral summer. The mechanisms that drive such changes and the fate of the carbon production are probably related to the variations in the limiting factors induced by the concurrent hydrological modifications to the Ross Sea, and they remain to be fully clarified. The comparison of conditions observed during summer 2014 and those reported for previous years reveal considerably different ecological assets that might be the result of current climate change. This suggests that further changes can be expected in the future, even at larger oceanic scales

Cognitive impairment in malignant forms of multiple sclerosis: balo, marburg, schilder

USMF "Nicolae Testemiţanu", Institutul de Neurologie şi NeurochirurgieMultiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system. The cognitive disorder can occur at any moment during the disease, in the presence or in the absence of the neurological disability. The performed neuropsychological studies certify that 45-65% of patients with multiple sclerosis have a certain degree of cognitive difficulty. The fulminatory, malign and acute forms of MS have certain pathophysiological and clinical presentation peculiarities that are common with those in MS, but in the same time different through evolutional and prognosis peculiarities. The cognitive disorders are a feature of the acute forms, which are violent from the very beginning and can have a subsequent development. In this article there are described 2 clinical cases of the MS fulminatory form, where the cognitive and behavioural severe disorders dominate the clinical picture from the very beginning of the disease. Scleroza multiplă (SM) este o maladie inflamatorie, demielinizantă a sistemului nervos central. Tulburarea cognitivă se poate dezvolta în orice moment pe parcursul maladiei, în prezenţa sau în absenţa dizabilităţii neurologice. În baza studiilor neuropsihologice efectuate s-a demonstrat, că 45- 65 % din pacienţii cu scleroză multiplă suferă de un grad de dificultate cognitivă. Formele fulminante, maligne, acute de SM au unele particularităţi patofiziologice şi de prezentare clinică comune cu cele din SM, dar totodată diferite, prin particularităţile evolutive şi de pronostic. O trăsătură a formelor acute o constituie tulburările cognitive, care sunt brutale de la debut şi se pot manifesta prin progresare ulterioară. În acest articol sunt prezentate 2 cazuri clinice de SM forma fulminantă, în care tulburările cognitive şi de comportament severe domina tabloul clinic chiar de la debutul maladiei

. Ecological role and phylogenetic position of a new habitat-forming species (Canalipalpata, Sabellidae) from the Mediterranean mesophotic soft-bottoms

This study presents a description of Bispira riccardi sp. nov., a new habitat-forming sabellid polychaete from the mesophotic NW Mediterranean Sea. Individuals, up to 20 cm long, show a peculiar morphology of radioles, thoracic uncini, companion chaetae and ventral shield of the collar. The phylogenetic position of this new taxon in the genus Bispira has been validated using nuclear (18S rRNA) and mitochondrial (COI) markers. Aggregations of B. riccardi sp. nov. were found by ROV on horizontal muddy bottoms between 56 and 85 m, in areas subjected to high trophic inputs. Patches are fragmented and dense (up to 943 individuals m 2) probably accounting for various hectares. A 5-days continuous monitoring, carried out using an autonomous lander, revealed that the contraction of the branchial crown was positively affected by temperature and current, rapidly responding to meteorological events. The filtering activity and high density of these fields suggest a considerable impact on the pelagic-benthic coupling and the amount of organic matter in the sediments. Indeed, meiofaunal abundance and diversity within the aggregations resulted significantly higher than in outer stations. These findings highlight the undisclosed potential of the deep Mediterranean Sea for sabellid diversity and their importance as habitat-forming species on mesophotic soft bottoms