Long-time behavior of an angiogenesis model with flux at the tumor boundary

This paper deals with a nonlinear system of partial differential equations modeling a simplified tumor-induced angiogenesis taking into account only the interplay between tumor angiogenic factors and endothelial cells. Considered model assumes a nonlinear flux at the tumor boundary and a nonlinear chemotactic response. It is proved that the choice of some key parameters influences the long-time behaviour of the system. More precisely, we show the convergence of solutions to different semi-trivial stationary states for different range of parameters.Comment: 17 page

Drought Resistance by Engineering Plant Tissue-Specific Responses

Drought is the primary cause of agricultural loss globally, and represents a major threat to food security. Currently, plant biotechnology stands as one of the most promising fields when it comes to developing crops that are able to produce high yields in water-limited conditions. From studies of Arabidopsis thaliana whole plants, the main response mechanisms to drought stress have been uncovered, and multiple drought resistance genes have already been engineered into crops. So far, most plants with enhanced drought resistance have displayed reduced crop yield, meaning that there is still a need to search for novel approaches that can uncouple drought resistance from plant growth. Our laboratory has recently shown that the receptors of brassinosteroid (BR) hormones use tissue-specific pathways to mediate different developmental responses during root growth. In Arabidopsis, we found that increasing BR receptors in the vascular plant tissues confers resistance to drought without penalizing growth, opening up an exceptional opportunity to investigate the mechanisms that confer drought resistance with cellular specificity in plants. In this review, we provide an overview of the most promising phenotypical drought traits that could be improved biotechnologically to obtain drought-tolerant cereals. In addition, we discuss how current genome editing technologies could help to identify and manipulate novel genes that might grant resistance to drought stress. In the upcoming years, we expect that sustainable solutions for enhancing crop production in water-limited environments will be identified through joint efforts

On providing mobility management in WOBANs: Integration with PMIPv6 and MIH

The Wireless-Optical Broadband Access Network (WOBAN) is a promising access architecture that combines the high performance of optical networks with the ubiquity and convenience of wireless technologies. This article proposes a network-based mobility framework that is specially tailored for WOBANs. The proposed architecture is based on Proxy Mobile IPv6 and IEEE 802.21 mobility management protocols, but it also defines a number of optimizations that enable the seamless handover of mobile nodes. In particular, the hierarchical architecture together with the broadcast-and-select nature of the optical part of the WOBAN are leveraged to: optimize the mobility of users with respect to the overall network resources, both at the wireless access and optical distribution parts, remove the overhead of IP-in-IP tunneling between the PMIPv6 entities, and perform an efficient bicasting during the handover process to minimize packet loss.The authors would like to acknowledge the support of the EU-funded MEDIEVAL (grant FP7-ICT-2009-5/258053), the CAM-funded Medianet project (under code S-2009/TIC-1468) and the MICINN research grant TIN2010-20136-C03.European Community's Seventh Framework ProgramPublicad

Spatially Resolved Star Formation Main Sequence of Galaxies in the Califa Survey

Cano-Díaz, M. et. al.The >main sequence of galaxies> - defined in terms of the total star formation rate ψ versus the total stellar mass M - is a well-studied tight relation that has been observed at several wavelengths and at different redshifts. All earlier studies have derived this relation from integrated properties of galaxies. We recover the same relation from an analysis of spatially resolved properties, with integral field spectroscopic (IFS) observations of 306 galaxies from the CALIFA survey. We consider the SFR surface density in units of log(M yr Kpc) and the stellar mass surface density in units of log(M Kpc) in individual spaxels that probe spatial scales of 0.5-1.5 Kpc. This local relation exhibits a high degree of correlation with small scatter (σ = 0.23 dex), irrespective of the dominant ionization source of the host galaxy or its integrated stellar mass. We highlight (i) the integrated star formation main sequence formed by galaxies whose dominant ionization process is related to star formation, for which we find a slope of 0.81 ± 0.02; (ii) for the spatially resolved relation obtained with the spaxel analysis, we find a slope of 0.72 ± 0.04; and (iii) for the integrated main sequence, we also identified a sequence formed by galaxies that are dominated by an old stellar population, which we have called the retired galaxies sequence.Financial support: M.C.D. and S.F.S.: DGAPA-UNAM funding; CONACyT-180125 and PAPIIT IA-100815 projects. Z.S.: EU Marie Curie Career Integration Grant >SteMaGE> PCIG12-GA-2012-326466. Y.A.: RyC-2011-09461 and AYA2013-47742-C4-3-P projects from the Spanish MINECO and the SELGIFS programme, funded by the EU (FP7-PEOPLE-2013-IRSES-612701). C.J.W.: Marie Curie Career Integration Grant 303912. R.M.G.D.: AyA2014-57490-P and J.A. P12-FQM2828 grants. J.F.B.: AYA2013-48226-C3-1-P from the Spanish MINECO grant. L.G.: Millennium Science Initiative through grant IC120009, and by CONICYT through FONDECYT grant 3140566.Peer Reviewe

Mobility management: deployment and adaptability aspects through mobile data traffic analysis

The expected boost in mobile data traffic and the evolution towards the next generation of networks are making cellular operators reconsider whether current approaches for handling mobility could be improved, according to the characteristics of the mobile traffic that actually flows through real networks. In this work, we make use of extensive analysis of real network traces to infer the main characteristics of mobile data traffic for a particular operator. Our analysis focuses on the features related to mobility, i.e., location information, number of handovers, or duration of the data traffic exchange. New techniques to gather the mobility characteristics of the user based on data and control packets correlation are designed and applied to compare the gains of deploying different mobility management approaches.The research leading to these results has received funding from the EU Seventh Framework Programme (FP7/2007-2013) under grant agreement 318115 (Connectivity management for eneRgy Op- timised Wireless Dense networks, CROWD). The work of Antonio de la Oliva has also been funded by the EU H2020 5G-Crosshaul Project (grant no. 671598)

Inflammatory Animal Model for Parkinson's Disease: The Intranigral Injection of LPS Induced the Inflammatory Process along with the Selective Degeneration of Nigrostriatal Dopaminergic Neurons

We have developed an animal model of degeneration of the nigrostriatal dopaminergic neurons, the neuronal system involved in Parkinson's disease (PD). The implication of neuroinflammation on this disease was originally established in 1988, when the presence of activated microglia in the substantia nigra (SN) of parkinsonians was reported by McGeer et al. Neuroinflammation could be involved in the progression of the disease or even has more direct implications. We injected 2 μg of the potent proinflammatory compound lipopolysaccharide (LPS) in different areas of the CNS, finding that SN displayed the highest inflammatory response and that dopaminergic (body) neurons showed a special and specific sensitivity to this process with the induction of selective dopaminergic degeneration. Neurodegeneration is induced by inflammation since it is prevented by anti-inflammatory compounds. The special sensitivity of dopaminergic neurons seems to be related to the endogenous dopaminergic content, since it is overcome by dopamine depletion. Compounds that activate microglia or induce inflammation have similar effects to LPS. This model suggest that inflammation is an important component of the degeneration of the nigrostriatal dopaminergic system, probably also in PD. Anti-inflammatory treatments could be useful to prevent or slow down the rate of dopaminergic degeneration in this disease

"Narrow" Graphene Nanoribbons Made Easier by Partial Hydrogenation

It is a challenge to synthesize graphene nanoribbons (GNRs) with narrow widths and smooth edges in large scale. Our first principles study on the hydrogenation of GNRs shows that the hydrogenation starts from the edges of GNRs and proceeds gradually toward the middle of the GNRs so as to maximize the number of carbon-carbon $\pi$-$\pi$ bonds. Furthermore, the partially hydrogenated wide GNRs have similar electronic and magnetic properties as those of narrow GNRs. Therefore, it is not necessary to directly produce narrow GNRs for realistic applications because partial hydrogenation could make wide GNRs "narrower"

Facile Synthesis of High Quality Graphene Nanoribbons

Graphene nanoribbons have attracted attention for their novel electronic and spin transport properties1-6, and because nanoribbons less than 10 nm wide have a band gap that can be used to make field effect transistors. However, producing nanoribbons of very high quality, or in high volumes, remains a challenge. Here, we show that pristine few-layer nanoribbons can be produced by unzipping mildly gas-phase oxidized multiwalled carbon nanotube using mechanical sonication in an organic solvent. The nanoribbons exhibit very high quality, with smooth edges (as seen by high-resolution transmission electron microscopy), low ratios of disorder to graphitic Raman bands, and the highest electrical conductance and mobility reported to date (up to 5e2/h and 1500 cm2/Vs for ribbons 10-20 nm in width). Further, at low temperature, the nanoribbons exhibit phase coherent transport and Fabry-Perot interference, suggesting minimal defects and edge roughness. The yield of nanoribbons was ~2% of the starting raw nanotube soot material, which was significantly higher than previous methods capable of producing high quality narrow nanoribbons1. The relatively high yield synthesis of pristine graphene nanoribbons will make these materials easily accessible for a wide range of fundamental and practical applications.Comment: Nature Nanotechnology in pres