Towards a compact representation of temporal rasters

Big research efforts have been devoted to efficiently manage spatio-temporal data. However, most works focused on vectorial data, and much less, on raster data. This work presents a new representation for raster data that evolve along time named Temporal k^2 raster. It faces the two main issues that arise when dealing with spatio-temporal data: the space consumption and the query response times. It extends a compact data structure for raster data in order to manage time and thus, it is possible to query it directly in compressed form, instead of the classical approach that requires a complete decompression before any manipulation. In addition, in the same compressed space, the new data structure includes two indexes: a spatial index and an index on the values of the cells, thus becoming a self-index for raster data.Comment: This research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941. Published in SPIRE 201

Regional coherence evaluation in mild cognitive impairment and Alzheimer's disease based on adaptively extracted magnetoencephalogram rhythms

This study assesses the connectivity alterations caused by Alzheimer's disease (AD) and mild cognitive impairment (MCI) in magnetoencephalogram (MEG) background activity. Moreover, a novel methodology to adaptively extract brain rhythms from the MEG is introduced. This methodology relies on the ability of empirical mode decomposition to isolate local signal oscillations and constrained blind source separation to extract the activity that jointly represents a subset of channels. Inter-regional MEG connectivity was analysed for 36 AD, 18 MCI and 26 control subjects in δ, θ, α and β bands over left and right central, anterior, lateral and posterior regions with magnitude squared coherence—c(f). For the sake of comparison, c(f) was calculated from the original MEG channels and from the adaptively extracted rhythms. The results indicated that AD and MCI cause slight alterations in the MEG connectivity. Computed from the extracted rhythms, c(f) distinguished AD and MCI subjects from controls with 69.4% and 77.3% accuracies, respectively, in a full leave-one-out cross-validation evaluation. These values were higher than those obtained without the proposed extraction methodology

Early psychological trauma and adolescence: a psychodynamic approach

After a brief historical  aspects of the concept of trauma are discussed (epidemiological, clinical and therapeutic). It suggests that there should be no confusion between the various aspects and their function (research or therapy). In the clinical work with adolescens trauma should be considered as a basically therapeutic tool. Trauma is an active giving of sense to an accumulation of events in the family history. Recognizing trauma early on, especially in our work with adolescents, transforms our therapies

Steam reforming of pyrolysis oil using nickel-spinel based catalysis

Introduction – Rationale In many areas worldwide, electricity is mainly produced using fuelled generators or as a supplementary power source. The energy efficiency of those units is typically below 30% excluding production and distribution costs. Replacing the fossil fuels used in electricity production with biofuels will allow for lower carbon print, although the amount of biomass available may not be sufficient in arid areas such as the Canadian arctic. It is therefore necessary to reduce the consumption of the propellant by the unit. Fuel cells, which reach an efficiency of 65%, reduce the amount of fuel required by half. Fuel cells do not use liquid fuels directly, but rather a reformer is included to the device to reform the biofuel into syngas or hydrogen-rich syngas. The challenge with reforming complex molecules into syngas lies with carbon deposition. For example, Chen et al.1 tested the La1-xKxMnO3 catalyst, while Xing et al.2 performed catalysis of Co, Ni and Rh over MgAl2O4 for steam reforming of pyrolytic oil from vegetal and both observed carbon deposition. This work focuses on the steam reforming of pyrolytic oils originating from plastic and vegetal materials as biofuels. A comparison is drawn between the behavior of (a) a nickel-alumina spinel catalyst mixed with yttrium oxide stabilized zirconia (YSZ), and (b) a catalyst made of mine wastes (known as UGS), impregnated with nickel. The NiAl2O4-YSZ catalyst used in this study has already been tested for steam reforming of diesel3-5 and other liquid hydrocarbons6 and dry reforming of methane7-8 while the Ni-UGS catalyst has been tested for dry and steam reforming of methane9. Please click Additional Files below to see the full abstract

Observed 1970-2005 cooling of summer daytime temperatures in coastal California

This study evaluated 1950–2005 summer [June–August (JJA)] mean monthly air temperatures for two California air basins: the South Coast Air Basin (SoCAB) and the San Francisco Bay Area (SFBA). The study focuses on the more rapid post-1970 warming period, and its daily minima temperature Tmin and maxima temperature Tmax values were used to produce average monthly values and spatial distributions of trends for each air basin. Additional analyses included concurrent SSTs, 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) sea level coastal pressure gradients, and GCM-downscaled average temperature Tave values. Results for all 253 California National Weather Service (NWS) Cooperative Observer Program (COOP) sites together showed increased Tave values (0.23°C decade−1); asymmetric warming, as Tmin values increase faster than Tmax values (0.27° versus 0.04°C decade−1) and thus decreased daily temperature range (DTR) values (0.15°C decade−1). The spatial distribution of observed SoCAB and SFBA Tmax values exhibited a complex pattern, with cooling (−0.30°C decade−1) in low-elevation coastal areas open to marine air penetration and warming (0.32°C decade−1) in inland areas. Results also showed that decreased DTR values in the basins arose from small increases at inland sites (0.16°C decade−1) combined with large decreases (−0.58°C decade−1) at coastal sites. It is also possible that some of the current observed temperature trends could be associated with low-frequency decadal variability, expected even with a constant radiative forcing. Previous studies suggest that cooling JJA Tmax values in coastal California were a result of increased irrigation, coastal upwelling, or cloud cover. The current hypothesis is that they arise (as a possible “reverse reaction”) from the global warming of inland areas, which results in increased sea-breeze flow activity. GCM model Tave warming decreased from 0.13°C decade−1 at inland sites to 0.08°C decade−1 in coastal areas. Sea level pressure increased in the Pacific high and decreased in the thermal low. The corresponding gradient thus showed a trend of 0.04 hPa 100 km−1 decade−1, supportive of the hypothesis of increased sea-breeze activity

Cherry-stones-based activated carbons as potential adsorbents for CO2/CH4 separation: effect of the activation parameters

This is the accepted version of the following article: Álvarez-Gutiérrez, N., Victoria Gil, M., Rubiera, F. and Pevida, C. (2015), Cherry-stones-based activated carbons as potential adsorbents for CO2/CH4 separation: effect of the activation parameters. Greenhouse Gas Sci Technol, 5: 812–825. doi: 10.1002/ghg.1534, which has been published in final form at http://dx.doi.org/10.1002/ghg.1534A low-cost biomass, cherry stones (CS), was used as a carbon precursor to synthesize two activated carbons to be used for CO2/CH4 separation. Single-step activation with two activating agents, carbon dioxide and steam, was used. The activation conditions that maximize the CO2 adsorption capacity by the adsorbents at 25 ºC and atmospheric pressure were determined by response surface methodology (RSM). The optimum values were 885 ºC and 12% of solid yield when activating with carbon dioxide, but 850 ºC and 15.3% of solid yield when activating with steam. Heating rate did not show a significant effect on the CO2 uptake. CO2 adsorption capacity values up to 11.45 and 10.56 wt.% were achieved under such conditions using carbon dioxide and steam as activating agents, respectively. Carbon dioxide activation promoted the development of microporosity, whereas both micropores and mesopores were developed during steam activation. The CO2/CH4 separation performance at 3 bar of the optimum adsorbents indicated that both cherry-stones-based activated carbons could have great potential as CO2 adsorbents for CO2/CH4 separation. The adsorbent activated with carbon dioxide, CS-CO2, showed a slightly higher adsorption capacity, but the steam-activated sample, CS-H2O, had an enhanced selectivity to separate CO2 from CO2/CH4 binary mixtures.This work was carried out with financial support from the Spanish MINECO (Project ENE2011-23467), co-financed by the European Regional Development Fund (ERDF) and from the Gobierno del Principado de Asturias (PCTI-GRUPIN14-079)Peer reviewe

Wave breaking along the stratospheric polar vortex as seen in ERA-40 data

Planetary wave breaking through the depth of the Northern Hemispheric stratosphere is observed in daily ERA-40 reanalysis data. Strong wave breaking along the vortex edge is objectively diagnosed by noting the large-scale overturning of potential vorticity contours on isentropic surfaces spanning the stratospheric vortex. Breaking events show distinctly different climatologies depending on whether they occur along the upper or lower portion of the stratospheric vortex. During early winter there is a strong negative correlation between the frequency of breaking events in these two regions. Frequent wave breaking in the lower stratosphere in early winter appears to both shield the upper portion of the vortex from wave disturbances and reduce the net upward wave activity flux into the troposphere, thereby allowing the vortex to strengthen into mid-winter