Effect of Maternal Hypoxia on Fetal Development: Programming of HIE Phenotype in Neonatal Rat Brain

Developmental programming of health and disease correlates the adverse intrauterine environment and the risk of disease later in life as cardiovascular disease, metabolic diseases, renal dysfunction or neurobehavioral disorders among others. Maternal hypoxia is one of the most common intrauterine growth restricted environment during pregnancy. Perinatal hypoxic-ischemic encephalopathy is an important cause of brain injury in the newborn due to a systematic asphyxia. Our study aims to test the hypothesis that maternal hypoxia affect the organogenesis of the kidney by affecting the kidney structure and focusing on the roles of AT1R and AT2R, while the brain development will also be affected by this maternal insult increasing the vulnerability of this to HIE brain injury and the role of GR and the epigenetic modification that regulate the expression of the GR will be assessed. Finally, the MAPK/ERK pathway as part of the downstream of the neuroprotective mechanism of the GR against neonate HIE brain injury will be evaluated. To address these issues two rats model were established: perinatal hypoxia exposure model in time-dated pregnant rats and hypoxic-ischemic encephalopathy in 10-day-old rat pups. Through these studies we found that maternal hypoxia decrease the number of glomeruli in offspring rat kidneys and a down-regulation on the expression of AT1R was observed in the kidneys of the adult rats in a sex dimorphism way, affecting more the females than the males. In addition, we observed that maternal hypoxia increased the vulnerability of the brain to HIE on P-10 pups by repressing the expression of GR. Epigenetics studies demonstrated that this down-regulation of GR was due to hypermethylation on promoter region of exon variants 17 and 111 of the GR gene. Dexamethasone, a synthetic glucocorticoid, treatment on normoxic P-10 brains increased the expression of LPGDS, and pERK44 and also the level of prostaglandin D2, while, the neuroprotective effect of dexamethasone observed against HIE brain injury on P-10 pups was diminished by MAPK/ERK and LPGDS inhibitor, and by blocking the DP1 receptor. These findings provide a new insight in understanding the pathogenesis of HIE in newborns and may suggest potential targets for the prevention and treatment of HIE brain injury

Single-atom control of the optoelectronic response in sub-nanometric cavities

By means of ab-initio time dependent density functional theory calculations carried out on an prototypical hybrid plasmonic device (two metallic nanoparticles bridged by a one-atom junction), we demonstrate the strong interplay between photoinduced excitation of localized surface plasmons and electron transport through the single atom. Such an interplay is remarkably sensitive to the atomic orbitals of the junction. Therefore, we show the possibility of a twofold tuning (plasmonic response and photoinduced current across the juntion) just by changing a single atom in the device.Comment: 5 pages, 5 figure

Electrically controllable magnetism in twisted bilayer graphene

Twisted graphene bilayers develop highly localised states around AA-stacked regions for small twist angles. We show that interaction effects may induce either an antiferromagnetic (AF) and a ferromagnetic (F) polarization of said regions, depending on the electrical bias between layers. Remarkably, F-polarised AA regions under bias develop spiral magnetic ordering, with a relative $120^\circ$ misalignment between neighbouring regions due to a frustrated antiferromagnetic exchange. This remarkable spiral magnetism emerges naturally without the need of spin-orbit coupling, and competes with the more conventional lattice-antiferromagnetic instability, which interestingly develops at smaller bias under weaker interactions than in monolayer graphene, due to Fermi velocity suppression. This rich and electrically controllable magnetism could turn twisted bilayer graphene into an ideal system to study frustrated magnetism in two dimensions, with interesting potential also for a range of applications.Comment: 7 pages, 3 figures. Minor correction

Modelling the impact of liner shipping network perturbations on container cargo routing: Southeast Asia to Europe application

Understanding how container routing stands to be impacted by different scenarios of liner shipping network perturbations such as natural disasters or new major infrastructure developments is of key importance for decision-making in the liner shipping industry. The variety of actors and processes within modern supply chains and the complexity of their relationships have previously led to the development of simulation-based models, whose application has been largely compromised by their dependency on extensive and often confidential sets of data. This study proposes the application of optimisation techniques less dependent on complex data sets in order to develop a quantitative framework to assess the impacts of disruptive events on liner shipping networks. We provide a categorization of liner network perturbations, differentiating between systemic and external and formulate a container assignment model that minimises routing costs extending previous implementations to allow feasible solutions when routing capacity is reduced below transport demand. We develop a base case network for the Southeast Asia to Europe liner shipping trade and review of accidents related to port disruptions for two scenarios of seismic and political conflict hazards. Numerical results identify alternative routing paths and costs in the aftermath of port disruptions scenarios and suggest higher vulnerability of intra-regional connectivity

Star Formation in a Stellar Mass Selected Sample of Galaxies to z=3 from the GOODS NICMOS Survey (GNS)

We present a study of the star-forming properties of a stellar mass-selected sample of galaxies in the GOODS NICMOS Survey (GNS), based on deep Hubble Space Telescope imaging of the GOODS North and South fields. Using a stellar mass selected sample, combined with HST/ACS and Spitzer data to measure both UV and infrared derived star formation rates (SFR), we investigate the star forming properties of a complete sample of ~1300 galaxies down to log M*=9.5 at redshifts 1.5<z<3. Eight percent of the sample is made up of massive galaxies with M*>10^11 Msun. We derive optical colours, dust extinctions, and ultraviolet and infrared SFR to determine how the star formation rate changes as a function of both stellar mass and time. Our results show that SFR increases at higher stellar mass such that massive galaxies nearly double their stellar mass from star formation alone over the redshift range studied, but the average value of SFR for a given stellar mass remains constant over this 2 Gyr period. Furthermore, we find no strong evolution in the SFR for our sample as a function of mass over our redshift range of interest, in particular we do not find a decline in the SFR among massive galaxies, as is seen at z < 1. The most massive galaxies in our sample (log M*>11) have high average SFRs with values, SFR(UV,corr) = 103+/-75 Msun/yr, yet exhibit red rest-frame (U-B) colours at all redshifts. We conclude that the majority of these red high-redshift massive galaxies are red due to dust extinction. We find that A(2800) increases with stellar mass, and show that between 45% and 85% of massive galaxies harbour dusty star formation. These results show that even just a few Gyr after the first galaxies appear, there are strong relations between the global physical properties of galaxies, driven by stellar mass or another underlying feature of galaxies strongly related to the stellar mass.Comment: 18 pages, 10 figures, accepted for publication in MNRA

Thread-like tentacles in the Mediterranean corals Paramuricea clavata and Corallium rubrum

The occurrence of modified tentacles (i.e. thread-like tentacles) in the Mediterranean octocorals Paramuricea clavata and Corallium rubrum is reported. Colonies of four species of Mediterranean gorgonians were maintained in aquarium conditions for more than 5 months. The development of thread-like tentacles has been observed only in two of the four species. The presence of modified tentacles in other cnidarians has been usually associated with defensive/aggressive behavior. Our observations showed that thread-like tentacles in P. clavata and C. rubrum can also be used for feeding

Influencia del tamaño mínimo de elemento en el análisis tridimensional por elementos finitos del cierre de grieta inducido por plasticidad

Because of the increase of the computational power, during last years the use of three-dimensional finite element models to analyse the plasticity induced crack closure phenomenon has spread. However, the methodology employed is directly inherit from bi-dimensional analysis. As is well known, several numerical parameters can affect to the obtained results, being one of them, the mesh size close to the crack front. In the present work, a CT aluminium alloy specimen has been three-dimensionally modelled in order to analyse the influence of the mesh size close to the crack front. The results have been analysed in terms of the crack opening and closure values as well as taking into account the strain and stress fields around the crack front.Debido al incremento de la capacidad computacional disponible hoy en día, en los últimos años se ha extendido el uso de modelos tridimensionales para el análisis del cierre de grieta en fatiga empleando el método de los elementos finitos. Sin embargo, la metodología que se emplea es directamente heredada de los modelos bidimensionales. Es bien conocido que diferentes parámetros numéricos pueden afectar a los resultados obtenidos, siendo uno de ellos el tamaño de la malla en el entorno del frente de la grieta. En el presente trabajo, se ha modelado tridimensionalmente una probeta CT de una aleación de aluminio, con objeto de evaluar la influencia del tamaño de la malla en el entorno del frente de la grieta, analizando los resultados en función de los valores de apertura y cierre de la grieta, así como considerando los campos de tensiones y deformaciones entrono al frente de la grieta.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Rapidly accelerating subsidence in the Greater Vancouver region from two decades of ERS-ENVISAT-RADARSAT-2 DInSAR measurements

Rapidly accelerating ground subsidence in the south-western part of British Columbia, the third largest metropolitan area in Canada with over 2.3 million of inhabitants, is estimated using the Multidimensional Small Baseline Subset (MSBAS) advanced Differential Interferometric Synthetic Aperture Radar (DInSAR), an effective processing strategy for multi-mission, multi-temporal SAR data. The Synthetic Aperture Radar (SAR) data used in this study consists of seven independent data sets: one ascending and one descending ERS-1/2 and ENVISAT frames, together spanning July 1995–September 2010, and three RADARSAT-2 frames spanning February 2009–October 2012. During the July 1995–October 2012 period we observe fast ground subsidence with a maximum rate of about 2 cm/year in the Greater Vancouver region that includes the Fraser River Delta and the cities of Burnaby, Richmond, Surrey, New Westminster and Vancouver. The rapidly accelerating subsidence is observed beneath the Vancouver International Airport, SkyTrain terminal as well as several agricultural and industrial locales. These time series suggest that the subsidence rate at the studied regions does not decrease with time, as suggested in previous studies, but remains steady or increases. These results also demonstrate the importance of acquiring and appropriately estimating longer time series, as previous studies on the same Greater Vancouver area may have misinterpreted the long term ground deformation rate and direction and underestimated the potential hazard. The long term impact of this subsidence on urban infrastructure can be significant and needs to be investigated further.The work of PG was supported by Banting Postdoctoral Fellowship. The work of KFT was supported by an NSERC Discovery Grant.Peer reviewe