Modeling discards in Trawling Mediterranean Northern Alboran Sea Fishery

Target and Bycatch species metrics estimated from fishery-dependent data were explored to assess their use in governance of habitat conservation in respect to fisheries. Fishing data collected by onboard observers in otter-trawl boats between 2011 and 2012 at monthly sampling frequency in the Alboran Sea (Western Mediterranean) were used to build maps of sensitivity to fishing stress. Maps were drawn by means kriging interpolation techniques of biomass and abundance (Catch Per Unit of Effort, CPUE) in kilogram and number per fishing hour of blue whiting (Micromesistius poutassou), European hake (Merluccius merluccius), and red mullets (Mullus barbatus and Mullus surmuletus) target species, seabreams (Pagellus acarne, Pagellus bogaraveo, and Pagellus erythrinus), and mackerels (Trachurus mediterraneus, Trachurus trachurus, and Trachurus picturatus) bycatch species and Bogue (Boops boops) bycatch discarded species. Modelling discards by means Generalised Additive Models (GAMs) use environmental (sea surface temperature and chlorophyll-a from satellite data and NAO climatic index); spatial (latitude, longitude, depth and port) and temporal (season, haul duration, moon phase), as well as technical (boat length and power) explanatory variables. The main causes of discards, for both target and bycatch species, are associated to the seasonality of the recruitment and the changes on the spatial distribution of habitat preferences along their ontogeny. Environmental variables did not reveal significant effects, showing that operational oceanography standard products must be not enough to assess discards, and therefore products providing information on specific ecological processes to discards must be designed with this purpose. In Bycatch species, such as sea breams, mackerels and bogue, discards were also highly dependent of the port and boat (fleet/boat strategies, power, etc, and market preferences). The higher discards corresponded to these bycatch pelagic or bentho-pelagic species. Keywords: Discards, Otter-trawl fisheries, fishery conservation, operational oceanography, spatial modelin

Heterogeneous nanotribological response of polymorphic self-assembled monolayers arising from domain and phase dependent friction

Micro-/nanoelectromechanical systems demand robust ultrathin films for lubrication. As they can drastically modify the frictional properties of surfaces, few nanometers thick self-assembled monolayers (SAMs) constitute accepted candidates as boundary lubricants. Their high stability and easy preparation make them attractive also for low cost applications. Given their high order, organosulfur SAMs have been archetypal systems for structural investigations, but few efforts have been devoted to analyze the influence of lateral inhomogeneities on their surface properties. The impact on the frictional response of the surface due to the existence of crystalline domains with lateral dimension in the sub-micrometer range is considered here. To this end, two polymorphic structures of self-assembled monolayers of ω-(4′-methylbiphenyl-4-yl) butane-1-thiol coexisting on Au(111) are investigated by scanning tunneling and force microscopy. Described by rectangular 5(raiz de 5) x3 (α-phase) and oblique 6 (raiz de 3) x 2 (raiz de 3) (β-phase) unit cells, they exhibit pronouncedly different frictional responses. The lateral nano-tribological heterogeneity of the surface is further influenced by the azimuthal orientation dependence of friction for each phase. In particular, this phenomenon is exploited in the less densely packed β-phase for which the separate analysis of forward and backward lateral force scans is used to differentiate domains rotated 180°. The results demonstrate the level of structural control required in the design of SAMs for nano-tribology applications.This work has been supported by the Spanish Government through grants MAT2010-20020 and NANOSELECT CSD2007-00041. M. Paradinas thanks financial support through the Spanish BES-2008-003588 FPI fellowship and C. Munuera from the ‘‘Juan de la Cierva’’ postdoctoral program JCI-2011-08815. Partial support by EPSRC (EP/E061303/1, EP/D036828/1) is also gratefully acknowledged.Peer Reviewe

Decoding crystallographic domains of molecular systems by cantilever torsion imaging

Resumen del póster presentado a la 13th European Conference on Surface Crystallography and Dynamics, celebrada en Donostia-San Sebastián (España) del 19 al 21 de junio de 2017.From the physical point of view, the tribological response, in particular frictional properties, of organic surfaces is an obvious subject of interest by itself. As a powerful tool to understand different dissipation mechanisms at surfaces, we commonly employ the scanning force microscope by measuring the lateral force perpendicular to the scan direction (also known as friction force microscopy, FFM). As for inorganic materials, FFM helps visualizing regions of different chemical nature. However, more subtle surface characteristics influence the frictional properties of molecular systems and well-designed and sensitive FFM measurements permit obtaining detailed structural details as molecular order (stick-slip) as well as molecular tilt angles and/or tilt angle azimuths. This is the case of observing friction anisotropy or friction asymmetry. The term anisotropy refers to the variation of friction with the relative orientation angle between sliding surfaces and is commonly correlated with surface crystallographic orientations, while asymmetry refers to a change in friction when the sliding direction is changed by 180°. FFM has been successfully employed in organic self-assembled monolayers (SAMs) not only to discriminate between ordered configurations presenting different friction coefficients or different packing, but also to decipher between equivalent structural domains as well as to identify highly dissipative transient molecular configurations during phase transitions. Outstandingly, crystallographic aspects including "stick-slip" can also be extracted from the torsion of the cantilever during scanning along its axis in the so-called transverse shear microscopy (TSM).Peer reviewe

Chemical shifts assignments of the archaeal MC1 protein and a strongly bent 15 base pairs DNA duplex in complex

International audienceMC1 is the most abundant architectural protein present in Methanosarcina thermophila CHTI55 in laboratory growth conditions and is structurally unrelated to other DNA-binding proteins. MC1 functions are to shape and to protect DNA against thermal denaturation by binding to it. Therefore, MC1 has a strong affinity for any double-stranded DNA. However, it recognizes and preferentially binds to bent DNA, such as four-way junctions and negatively supercoiled DNA minicircles. Combining NMR data, electron microscopy data, biochemistry, molecular modelisation and docking approaches, we proposed recently a new type of DNA/protein complex, in which the monomeric protein MC1 binds on the concave side of a strongly bent 15 base pairs DNA. We present here the NMR chemical shifts assignments of each partner in the complex, 1H 15N MC1 protein and 1H 13C 15N bent duplex DNA, as first step towards the first experimental 3D structure of this new type of DNA/protein complex