Environmental and human factors drive the subtropical marine forests of Gongolaria abies-marina to extinction

Large brown macroalgae are foundational threatened species in coastal ecosystems from the subtropical northeastern Atlantic, where they have exhibited a drastic decline in recent years. This study describes the potential habitat of Gongolaria abies-marina, its current distribution and conservation status, and the major drivers of population decline. The results show a strong reduction of more than 97% of G. abies-marina populations in the last thirty years and highlight the effects of drivers vary in terms of spatial heterogeneity. A decrease in the frequency of high waves and high human footprint are the principal factors accounting for the long-term decline in G. abies-marina populations. UV radiation and sea surface temperature have an important correlation only in certain locations. Both the methodology and the large amount of data analyzed in this study provide a valuable tool for the conservation and restoration of threatened macroalgae.En prensa1,95

Papel de la eminencia talámica, el sistema olfativo principal y el sistema olfativo accesorio en la maduración sexual del encéfalo y las manifestaciones clínico-morfológicas del síndrome de Kallmann

El desarrollo de sistema olfativo y la diferenciación sexual del encéfalo, tanto en el hombre como en los animales, están estrechamente relacionados. Actualmente, se describe la imbricación entre la formación del sistema olfativo principal y la migración de las neuronas que sintetizan la hormona liberadora de gonadotrofinas (GnRF). Estas neuronas GnRF se desplazan por los nervios olfatorios, desde la parte medial del epitelio nasal al bulbo olfatorio, continúan por el encéfalo rostral hasta alcanzar el hipotálamo anterior. Por otro lado, el síndrome de Kallmann es un trastorno genético en el cual se combina el hipogonadismo hipogonadotrópico y la anosmia. El hipogonadismo se caracteriza por la ausencia o reducción de los niveles de hormona liberadora de gonadotrofinas y la anosmia la aplasia del bulbo olfatorio. En esta revisión se analizan las estructuras responsables de la maduración del sistema olfativo principal y accesorio, la diferenciación sexual del encéfalo y su relación con todas las manifestaciones clínicas y morfológicas del síndrome Kallmann. The olfactory system development and brain sexual maturation, in man and animals, are closely related. Currently the overlap between the formation of the olfactory system and the migration of neurons that synthesize gonadotropin-releasing hormone (GnRF) are described. The GnRF neurons migrate from the medial portion of the nasal epithelium through the olfactory nerves and the main olfactory bulb to the anterior hypothalamus. Furthermore, Kallmann syndrome (KS) is a genetic disorder in which combines hypogonadotropic hypogonadism and anosmia. Hypogonadism is characterized by the absence or reduced levels of gonadotropin-releasing hormone and anosmia is due to aplasia of the olfactory bulb. The basic clinical manifestations of KS are: anosmia and the absence of puberty. The structures responsible for the maturation of the main and accessory olfactory systems, the sexual differentiation of the brain and its relationship with all the clinical manifestations of Kallmann syndrome are analyzed in this revie

Survey of the analysis of continuous conformational variability of biological macromolecules by electron microscopy

Single-particle analysis by electron microscopy is a well established technique for analyzing the three-dimensional structures of biological macromolecules. Besides its ability to produce high-resolution structures, it also provides insights into the dynamic behavior of the structures by elucidating their conformational variability. Here, the different image-processing methods currently available to study continuous conformational changes are reviewedThe authors would like to acknowledge support from the Spanish Ministry of Economy and Competitiveness through grants BIO2013-44647-R and BIO2016-76400-R (AEI/ FEDER, UE), Comunidad Autonoma de Madrid through grant S2017/BMD-3817, Instituto de Salud Carlos III through grants PT13 /0001/0009 and PT17/0009/0010,the European Union (EU) and Horizon 2020 through West-Life (EINFRA- 2015-1, Proposal 675858), CORBEL (INFRADEV-1-2014-1, Proposal 654248), ELIXIR–EXCELERATE (INFRADEV-3- 2015, Proposal 676559), iNEXT (INFRAIA-1-2014-2015, Proposal 653706), EOSCpilot (INFRADEV-04-2016, Proposal 739563) and the National Institutes of Health (P41 GM 103712) (IB

Flexible workflows for on-the-fly electronmicroscopy single-particle image processing using Scipion

Electron microscopy of macromolecular structures is an approach that is in increasing demand in the field of structural biology. The automation of image acquisition has greatly increased the potential throughput of electron microscopy. Here, the focus is on the possibilities in Scipion to implement flexible and robust image-processing workflows that allow the electron-microscope operator and the user to monitor the quality of image acquisition, assessing very simple acquisition measures or obtaining a first estimate of the initial volume, or the data resolution and heterogeneity, without any need for programming skills. These workflows can implement intelligent automatic decisions and they can warn the user of possible acquisition failures. These concepts are illustrated by analysis of the well known 2.2 Å resolution β-galactosidase data setThe authors would like to acknowledge financial support from The Spanish Ministry of Economy and Competitiveness through the BIO2016-76400-R (AEI/FEDER, UE) grant, the Comunidad Auto´noma de Madrid through grant S2017/BMD3817, the Instituto de Salud Carlos III (PT17/0009/0010), the European Union (EU) and Horizon 2020 through the CORBEL grant (INFRADEV-1-2014-1, Proposal 654248), the ‘la Caixa’ Foundation (ID 100010434, Fellow LCF/BQ/ IN18/11660021), Elixir–EXCELERATE (INFRADEV-3- 2015, Proposal 676559), iNEXT (INFRAIA-1-2014-2015, Proposal 653706), EOSCpilot (INFRADEV-04-2016, Proposal 739563) and INSTRUCT–ULTRA (INFRADEV03-2016-2017, Proposal 731005

Evolution of austenite static recrystallization and grain size during hot rolling of a V-microalloyed steel

Laboratory double-deformation isothermal tests and multipass continuous cooling hot torsion tests were used to study the static recrystallization of austenite under isothermal and anisothermal conditions as well as to simulate the hot rolling of a 0.13% V-microalloyed steel. Characterization of the evolution of austenite microstructure was carried out. It has been verified that no-recrystallization temperature (Tnr) approximately corresponds to the temperature where recrystallization starts to be incomplete during rolling. However, incomplete recrystallization is visually evident at temperatures 25–50 °C below Tnr, where grain elongation and increase in aspect ratio with temperature drop start to be significant. An accurate method to estimate the recrystallized fraction during hot rolling from stress–strain data and with no need of metallographic studies has been designed. The results of this method have been compared to metallographic measurements, the values of anisothermal fractional softening and the accumulated stress measured in the MFS plots at T < Tnr. A pronounced austenite grain refinement has been detected in the first hot rolling passes after reheating, as grain size decreases from 155 μm to 27 μm in six passes. If the effect of grain size on recrystallization and precipitation is taken into account, the correlation of isothermal and continuous cooling tests as well as the relationship between SRCT and Tnr or RLT temperatures can be better understood.Peer reviewe

DEVELOPMENT OF A HIGH TOUGHNESS BAINITE IN A 38MnV7 STEEL

Previous works have shown that high toughness can be obtained in medium carbon bainitic steel (38MnV7) after a careful control of the chemistry and heat thermal treatment. Charpy-V tests at room temperature provided 40J for the steel after an isothermal bainitic treatment. Further improvement in toughness was obtained by subsequent tempering reaching an absorbed energy value of 50J with a FATT of -40ºC. Present work is oriented to an optimization of the above chemical composition. To attain this purpose six different casting were prepared, ranging the chemical composition as follows %C: 0.35-0.46, %Mn: 1.33-1.84, %V: 0.066 0.14% and %Ti: 0.010-0.025. To appropriate design the thermomechanical cycle, precipitation curves, TTT curves (including the effect of the initial grain size, i.e. austenitization temperature , were determined for each steelPeer Reviewe

Microstructural Unit Controlling Cleavage Crack Propagation in High Strength Bainitic Steels

The strengthening mechanisms which are operative in bainite are very well known: small bainite packet, small width of the laths, dislocation density and size and number of carbide particles (Fe3C), among others. Bainite packet size has been traditionally considered as the value measured by optical microscopy (OM), as electron back scattered diffraction (EBSD) technique is relatively recent. In a V-microalloyed steel with bainitic microstructure of C=0.38%, V=0.12% and N= 0.0214% the average length and width of ferrite laths and of cementite carbides were measured. On the other hand, the bainite packet size was measured by OM and EBSD with a misorientation of 15º. These values of the microstructural units have been taken in account to calculate the effective surface energy ¿p given by Griffith¿s model for cleavage fracture. It was concluded that bainite packet size determined by EBSD with a misorientation angle criterion of 15º was the microstructural parameter that controls cleavage crack propagation. Given the relationship between the average unit crack path (UCP) and the bainite packet size, it was concluded that the effective surface energy of cleavage fracture (¿p) would be between 71.6 and 82.6 J m-2.Peer Reviewe

Influence of the chemical composition and tempering treatment on the toughness of bainitic 38MnV7 steel

This work studies the influence of Mn and the V/N ratio on the toughness of 38MnV7 steel. Four steels with different Mn, N and Ti contents were studied. Lowering the Mn content to approximately 1.5% considerably enhanced toughness by reducing Mn segregation and consequently achieved a more uniform bainitic microstructure. Raising the N content to reach a V/N ratio of close to 5 enhanced the intragranular nucleation of bainite and thus also improved toughness. Isothermal transformation prevented the presence of retained austenite and allowed a complete bainitic transformation. One of the steels contained Ti to control austenite grain growth by the precipitation of TiN particles. However, the results showed that the presence of nanoparticles TiN did not improve the bainitic microstructure. In sum, the work has allowed the obtainment of a 38MnV7 steel with a toughness value (obtained in a Charpy V-Notch impact test) of close to 40 J, and higher than 50 J after tempering at 600 ºC. The steel shows a toughness of close to 20 J at -40 ºC. The optimal composition of the steel (in wt. %) was approximately: C=0.38; Mn=1.53; V=0.11; N=0.0217.Peer Reviewe