233 research outputs found

    Latency-aware resource orchestration in SDN-based packet over optical flexi-grid transport networks

    Get PDF
    In the upcoming 5G networks and following the emerging Software Defined Network/Network Function Virtualization (SDN/NFV) paradigm, demanded services will be composed of a number of virtual network functions that may be spread across the whole transport infrastructure and allocated in distributed Data Centers (DCs). These services will impose stringent requirements such as bandwidth and end-to-end latency that the transport network will need to fulfill. In this paper, we present an orchestration system devised to select and allocate virtual resources in distributed DCs connected through a multi-layer (Packet over flexi-grid optical) network. Three different on-line orchestration algorithms are conceived to accommodate the incoming requests by satisfying computing, bandwidth and end-to-end latency constraints, setting up multi-layer connections. We addressed end-to-end latency requirements by considering both network (due to propagation delay) and processing delay components. The proposed algorithms have been extensively evaluated and assessed (via a number of figures of merit) through experimental tests carried out in a Packet over Optical Flexi-Grid Network available in the ADRENALINE testbed with emulated DCs connected to it.This work has been partially funded by the EC H2020 5GTransformer Project (grant No. 761536)

    Soil carbon stocks and their variability across the forests, shrublands and grasslands of peninsular Spain

    Get PDF
    Accurate estimates of C stocks and fluxes of soil organic carbon (SOC) are needed to assess the impact of climate and land use change on soil C uptake and soil C emissions to the atmosphere. Here, we present an assessment of SOC stocks in forests, shrublands and grasslands of peninsular Spain based on field measurements in more than 900 soil profiles. SOC to a depth of 1 m was modelled as a function of vegetation cover, mean annual temperature, total annual precipitation, elevation and the interaction between temperature and elevation, while latitude and longitude were used to model the correlation structure of the errors. The resulting statistical model was used to estimate SOC in the ∼8 million pixels of the Spanish Forest Map (29.3 × 10⁶ ha). We present what we believe is the most reliable estimation of current SOC in forests, shrublands and grasslands of peninsular Spain thus far, based on the use of spatial modelling, the high number of profiles and the validity and refinement of the data layers employed. Mean concentration of SOC was 8.7 kg m-₂, ranging from 2.3 kg m-₂ in dry Mediterranean areas to 20.4 kg m-₂ in wetter northern locations. This value corresponds to a total stock of 2.544 Tg SOC, which is four times the amount of C estimated to be stored in the biomass of Spanish forests. Climate and vegetation cover were the main variables influencing SOC, with important ecological implications for peninsular Spanish ecosystems in the face of global change. The fact that SOC was positively related to annual precipitation and negatively related to mean annual temperature suggests that future climate change predictions of increased temperature and reduced precipitation may strongly reduce the potential of Spanish soils as C sinks. However, this may be mediated by changes in vegetation cover (e.g. by favouring the development of forests associated to higher SOC values) and exacerbated by perturbations such as fire. The estimations presented here provide a baseline to estimate future changes in soil C stocks and to assess their vulnerability to key global change drivers, and should inform future actions aimed at the conservation and management of C stocks

    Global transpiration data from sap flow measurements: the SAPFLUXNET database

    Get PDF
    Plant transpiration links physiological responses of vegetation to water supply and demand with hydrological, energy, and carbon budgets at the land–atmosphere interface. However, despite being the main land evaporative flux at the global scale, transpiration and its response to environmental drivers are currently not well constrained by observations. Here we introduce the first global compilation of whole-plant transpiration data from sap flow measurements (SAPFLUXNET, https://sapfluxnet.creaf.cat/, last access: 8 June 2021). We harmonized and quality-controlled individual datasets supplied by contributors worldwide in a semi-automatic data workflow implemented in the R programming language. Datasets include sub-daily time series of sap flow and hydrometeorological drivers for one or more growing seasons, as well as metadata on the stand characteristics, plant attributes, and technical details of the measurements. SAPFLUXNET contains 202 globally distributed datasets with sap flow time series for 2714 plants, mostly trees, of 174 species. SAPFLUXNET has a broad bioclimatic coverage, with woodland/shrubland and temperate forest biomes especially well represented (80 % of the datasets). The measurements cover a wide variety of stand structural characteristics and plant sizes. The datasets encompass the period between 1995 and 2018, with 50 % of the datasets being at least 3 years long. Accompanying radiation and vapour pressure deficit data are available for most of the datasets, while on-site soil water content is available for 56 % of the datasets. Many datasets contain data for species that make up 90 % or more of the total stand basal area, allowing the estimation of stand transpiration in diverse ecological settings. SAPFLUXNET adds to existing plant trait datasets, ecosystem flux networks, and remote sensing products to help increase our understanding of plant water use, plant responses to drought, and ecohydrological processes. SAPFLUXNET version 0.1.5 is freely available from the Zenodo repository (https://doi.org/10.5281/zenodo.3971689; Poyatos et al., 2020a). The “sapfluxnetr” R package – designed to access, visualize, and process SAPFLUXNET data – is available from CRAN.EEA Santa CruzFil: Poyatos, Rafael. Universitat Autònoma de Barcelona. Bellaterra (Cerdanyola del Vallès); EspañaFil: Poyatos, Rafael. CREAF. Bellaterra (Cerdanyola del Vallès); EspañaFil: Granda, Víctor. Universitat Autònoma de Barcelona. Bellaterra (Cerdanyola del Vallès); EspañaFil: Granda, Víctor. Joint Research Unit CREAF-CTFC. Bellaterra; EspañaFil: Flo, Víctor. Universitat Autònoma de Barcelona. Bellaterra (Cerdanyola del Vallès); EspañaFil: Adams, Mark A. Swinburne University of Technology. Faculty of Science Engineering and Technology; Australia.Fil: Adams, Mark A. University of Sydney. School of Life and Environmental Sciences; Australia.Fil: Adorján, Balázs. University of Debrecen. Faculty of Science and Technology. Department of Botany; HungríaFil: Aguadé, David. Universitat Autònoma de Barcelona. Bellaterra (Cerdanyola del Vallès); EspañaFil: Aidar, Marcos P. M. Institute of Botany. Plant Physiology and Biochemistry; BrasilFil: Allen, Scott. University of Nevada. Department of Natural Resources and Environmental Science; Estados UnidosFil: Alvarado-Barrientos, M. Susana. Instituto de Ecología A.C. Red Ecología Funcional; México.Fil: Anderson-Teixeira, Kristina J. Center for Tropical Forest Science-Forest Global Earth Observatory, Smithsonian Tropical Research Institute; PanamáFil: Anderson-Teixeira, Kristina J. Conservation Ecology Center. Smithsonian Conservation Biology Institute; Estados UnidosFil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Martínez-Vilalta, Jordi. CREAF. Bellaterra (Cerdanyola del Vallès); EspañaFil: Martínez-Vilalta, Jordi. Universitat Autònoma de Barcelona. Bellaterra (Cerdanyola del Vallès); Españ

    Leaf economics and plant hydraulics drive leaf : wood area ratios

    Get PDF
    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordData accessibility: All data are archived and are available from the TRY plant trait data base: www.try-db.org (https://doi.org/10.1111/j.1365-2486.2011.02451.x).Biomass and area ratios between leaves, stems and roots regulate many physiological and ecological processes. The Huber value Hv (sapwood area/leaf area ratio) is central to plant water balance and drought responses. However, its coordination with key plant functional traits is poorly understood, which prevents developing trait-based prediction models. Based on theoretical arguments, we hypothesise that global patterns in Hv of terminal woody branches can be predicted from variables related to plant trait spectra, i.e., plant hydraulics and size and leaf economics. Using a global compilation of 1135 species-averaged Hv , we show that Hv varies over 3 orders of magnitude. Higher Hv are seen in short small-leaved low-SLA shrubs with low Ks in arid relative to tall large-leaved high-SLA trees with high Ks in moist environments. All traits depend on climate but climatic correlations are stronger for explanatory traits than Hv . Negative isometry is found between Hv and Ks , suggesting a compensation to maintain hydraulic supply to leaves across species. This work identifies the major global drivers of branch sapwood/leaf area ratios. Our approach based on widely available traits facilitates the development of accurate models of aboveground biomass allocation and helps predict vegetation responses to drought.Spanish Ministry of Economy and Competitiveness (MINECO)University of NottinghamSwedish Research Council Forma

    Experimental Demonstration of Extended 5G Digital Fronthaul Over a Partially-Disaggregated WDM/SDM Network

    Get PDF
    © 2021 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] We experimentally demonstrate a 5G digital fronthaul network that relies on multi-adaptive bandwidth/bitrate variable transceivers (BVTs) and an autonomic software-defined networking (SDN) control system for partially-disaggregated wavelength division multiplexing (WDM)/space division multiplexing (SDM). Transmission of 256-QAM 760.32 MHz orthogonal frequency-division multiplexing (OFDM) radio signal is performed, with a total radio transmission capacity of 5.667 Gb/s. Digitized signal samples are carried as a 22.25 Gb/s digitized radio-over-fiber (DRoF) data stream and transmitted over a WDM/SDM infrastructure including 40-wavelength 100-GHz arrayed waveguide gratings (AWGs) and 19-core fiber. The autonomic SDN controller deploys a control loop for the multi-adaptive OFDM-based BVTs that monitors the per-subcarrier signal to noise ratio (SNR) and assigns the optimal constellation based on the actual signal degradation. An error vector magnitude (EVM) below the targeted 2.1% is achieved while setting up connections in less than 5 s.This work was supported in part by the EC H2020 BLUESPACE Project under Grant 762055 and in part by the Spanish MICINN AURORAS Project under Grant RTI2018-099178.Fabrega, JM.; Múñoz, R.; Nadal, L.; Manso, C.; Svaluto Moreolo, M.; Vilalta, R.; Martínez, R.... (2021). Experimental Demonstration of Extended 5G Digital Fronthaul Over a Partially-Disaggregated WDM/SDM Network. IEEE Journal on Selected Areas in Communications. 39(9):2804-2815. https://doi.org/10.1109/JSAC.2021.3064645S2804281539

    PK-guided switch between standard half-life and extended half-life factor VII products

    Get PDF
    P117 Introduction: Extended half-life (EHL) factor VIII (FVIII) requires improvements in half-life (t1/2) & area under the curve (AUC) of 1.3 & 1.25 times compared to standard half-life (SHL) products. The aim of this study is compare pharmacokinetics (PK) after the switch from SHL to EHL in patients with hemophilia A (HA). Methods: Multicenter comparative, cross-sectional, prospective study analyzing PK differences after switch from SHL to EHL (ef-moroctocog alfa [rFVIII-Fc] & rurioctocog alfa pegol [PEG-rFVIII]). WAPPS- Hemo® was used to analyze PK parameters with 2-3 samples: t1/2; AUC, peak level (PL); trough level at 24, 48 & 72 hours (TL24, TL48, TL72); & time to reach FVIII levels of 1, 2, 5% (T1%, T2%, T5%). Ratio of t1/2 & AUC, the number of weekly doses & the dose/kg/week before & after the switch were compared. Wilcoxon & Kruskal-Wallis tests (SPSS®) were used to compare the PK parameters. Results: Eightythree patients from 8 Spanish hospitals were analyzed (62 rFVIII-Fc; 21 PEG-rFVIII), 79 had severe HA & 4 moderate HA. Median age was 30 years (range = 3-64) & no differences in weight were observed between both periods.Dose/kg/week & weekly infusion frequency were reduced after the switch to EHL, & significant improvements were observed in all PK parameters after the change from SHL to EHL (Table 1). The median ratios of t1/2 & AUC were 1.3 (IQR:1.2-1.6) and 1.6 (IQR:1.3-2.2) in the entire cohort. In patients with =12 years ratios of t1/2 & AUC were 1.4 (IQR:1.3-1.6) & 1.7 (IQR:1.3-2.3), and in the cohort of 16 patients <12 years treated with rFVIII-Fc were 1.3 (IQR:0.9-1.5) and 1.4 (IQR:1.1- 2.1).After the switch to EHL, median weekly dose frequency (30%, IQR:0-33.3%) & dose/kg/week (16.9%, IQR:8.7-32.8%) were reduced. In a small subset of 15 younger patients the dose/kg/week was increased a median of 28.6% (IQR:11.7-40-7%). No differences were observed in any of the PK parameters & median ratios of t1/2 & AUC in patients aged =12 years treated with rFVIII-Fc vs. PEG-rFVIII (46 rFVIII-Fc; 21 PEG-rFVIII). Discussion/Conclusion: EHL FVIII have shown significant PK improvements in clinical real practice, allowing to reduce weekly infusion number & dose/kg/week. Outside the clinical trial setting, we have observed an increase in t1/2 & AUC ratios accordingly to EHL definition. Comparisons regarding clinical outcomes (bleeding rate after switch) will be performed after a follow-up of 1 year with EHL for the full cohort

    Control orchestration protocol:unified transport API for distributed cloud and network orchestration

    Get PDF
    In the context of the fifth generation of mobile technology (5G), multiple technologies will converge into a unified end-to-end system. For this purpose, software defined networking (SDN) is proposed, as the control paradigm will integrate all network segments and heterogeneous optical and wireless network technologies together with massive storage and computing infrastructures. The control orchestration protocol is presented as a unified transport application programming interface solution for joint cloud/network orchestration, allowing interworking of heterogeneous control planes to provide provisioning and recovery of quality of service (QoS)-aware end-to-end services. End-to-end QoS is guaranteed by provisioning and restoration schemes, which are proposed for optical circuit/packet switching restoration by means of signal monitoring and adaptive modulation and adaptive route control, respectively. The proposed solution is experimentally demonstrated in an international multi-partner test bed, which consists of a multi-domain transport network comprising optical circuit switching and optical packet switching domains controlled by SDN/OpenFlow and Generalized Multiprotocol Label Switching (GMPLS) control planes and a distributed cloud infrastructure. The results show the dynamic provisioning of IT and network resources and recovery capabilities of the architecture.Grant numbers : This work was partially supported by the Spanish MINECO project DESTELLO (TEC2015-69256-R)

    Experimental demonstration of advanced service management in SDN/NFV Fronthaul Networks deploying ARoF and PoF

    Get PDF
    We demonstrate two advanced services deployed in a novel SDN/NFV optical fronthaul network combining analog radio over fiber (ARoF) and power over fiber (PoF); vertical service management for virtual content delivery networks (vCDNs), and user mobility and remote optical power management for femto cells

    Material docent en format digital per a assignatures d'experimentació en química

    Get PDF
    En aquesta comunicació es presenta un projecte elaborat arran de l’interès mostrat per un grup de professorat en disposar de material audiovisual propi i comú per a assignatures experimentals de química de diferents titulacions impartides per diferents centres de la Universitat Politècnica de Catalunya (UPC). Els autors d’aquest treball pertanyen al Grup de Recursos per a la Didàctica de la Química (GReDiQ), integrat en el projecte RIMA (http://www.upc.edu/rima) de l’Institut de Ciències de l’Educació de la UPC. L’elaboració de material audiovisual digital constitueix un dels objectius principals plantejats pel GReDiQ i pretén generar tant un material de suport per a les activitats pre-laboratorio, com un element motivador i que faciliti l’aprenentatge de l’alumnat en les sessions de laboratori de les matèries de Química i Enginyeria química, que apareixen com assignatures de formació bàsica en gairebé tots els plans d’estudi dels nous Graus d’Enginyeria que s’ estan implantant a la UPC. La utilització del material audiovisual digital possibilita que l’alumnat prengui consciència de les activitats de laboratori, així com dels hàbits bàsics de manipulació i seguretat en el laboratori, del fonament d’operacions bàsiques o instrumentació a utilitzar.Peer Reviewe
    corecore