Near-Ground Wireless Coverage Design in Rural Environments

[EN] Due to the broad range of options that wireless systems offer, Wi-Fi products are increasingly being used in agriculture environments to improve farming practices and better control the output of the production. However, the foliage has proven to harm radio-frequency propagation as well as decreasing the coverage area of Wireless Sensor Networks (WSNs). Therefore, near-ground channel characterization can help in avoiding high antennas and vegetation. Nevertheless, theoretical models tend to fail when forecasting near-ground path losses. This paper aims at determining how the field components such as soil, grass and, trunks affect radio-links in near-ground scenarios. To do this, we measure the Received Signal Strength (RSSI), the Signal to Interference Ratio (SIR) and the Round-Trip Time (RTT) of a Wireless Local Area Network (WLAN), at different distances, and the results are compared with 3 prediction models: the Free-Space Propagation Model, Two-Ray Ground Reflection Model and, One-Slope Log-Normal Model. The experiment was carried out by collecting experimental data at two different locations, i.e., an orange tree plantation and a field without vegetation, taking measurements every meter. A comprehensive analysis of the influence of rural environments can help to obtain better near-ground WSN performance and coverage in precision agriculture.This work has been partially supported by European Union through the ERANETMED project ERANETMED3- 227 SMARTWATIR, by the Ministerio de Ciencia, Innovación y Universidades through the Ayudas para la adquisición de equipamiento científico-técnico, Subprograma estatal de infraestructuras de investigación y equipamiento científico-técnico (plan Estatal I+D+i 2017- 2020) (project EQC2018-004988-P), by the Universidad de Granada through the "Programa de Proyectos de Investigación Precompetitivos para Jóvenes Investigadores. Modalidad A jóvenes Doctores of "Plan Propio de Investigación y Transferencia 2019" (PPJIA2019.10) and by the Campus de Excelencia Internacional Global del Mar (CEI·Mar) through the "Ayudas Proyectos Jóvenes Investigadores CEI·Mar 2019" (Project CEIJ-020).Botella-Campos, M.; Jimenez, JM.; Sendra, S.; Lloret, J. (2020). Near-Ground Wireless Coverage Design in Rural Environments. IARIA XPS Press. 14-19. http://hdl.handle.net/10251/178039S141

In vivo immunomodulatory and antioxidant properties of nanoceria (nCeO2) in the marine mussel Mytilus galloprovincialis

Cerium nanoparticles (nCeO2) are increasingly utilized in a wide variety of industrial, environmental and biomedical applications, and are therefore expected to be released in the aquatic environment. Due to its peculiar redox properties, nCeO2 may present unique hazards to environmental and human health. Previous data showed that in the hemocytes of the marine bivalve Mytilus galloprovincialis, in vitro exposure to a particular type of nCeO2 (9 nm, characterized by negative ζ-potential, high H2O2 scavenging capacity and Ce3+/Ce4+ surface ratio) reduced basal ROS production, lysosomal membrane stability and phagocytic activity in the presence of hemolymph serum; the effects observed were partly ascribed to the formation of a SOD-protein corona in the hemolymph. In this work, the in vivo effects of this type of nCeO2 were investigated in mussels exposed to 100 μg/L nCeO2 for 96 h; several lysosomal, immune, inflammatory and antioxidant biomarkers were measured at cellular (hemocytes) and tissue (gills, digestive gland) level. Molecular responses were evaluated in hemocytes and digestive gland by determining expression of 11 selected genes related to known biological functions. The results show specific immunomodulatory and antioxidant effects of nCeO2 at different levels of biological organization in the absence of Cerium tissue accumulation. These data further support the redox mechanisms at the basis of the physiological effects of nCeO2. Finally, in order to evaluate the possible impact at the whole organism level, the effects of nCeO2 were evaluated in the 48 h embryotoxicity assay in a wide concentration range. However, nCeO2 exposure resulted in a small reduction in normal embryo development. Overall, the results demonstrate that in mussels nCeO2 can selectively modulate different physiological processes at different levels of biological organization

Ocean-Atmosphere CO2 Fluxes in the North Atlantic Subtropical Gyre: Association with Biochemical and Physical Factors during Spring

We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI).Sea surface partial pressure of CO2 (pCO2) was measured continuously in a transect of the North Atlantic subtropical gyre between Santo Domingo, Dominican Republic (18.1° N, 68.5° W) and Vigo, Spain (41.9° N, 11.8° W) during spring 2011. Additional biogeochemical and physical variables measured to identify factors controlling the surface pCO2 were analyzed in discrete samples collected at 16 sites along the transect at the surface and to a depth of 200 m. Sea surface pCO2 varied between 309 and 662 μatm, and showed differences between the western and eastern subtropical gyre. The subtropical gyre acted as a net CO2 sink, with a mean flux of −5.5 ± 2.2 mmol m−2 day−1. The eastern part of the transect, close to the North Atlantic Iberian upwelling off the Galician coast, was a CO2 source with an average flux of 33.5 ± 9.0 mmol m−2 day−1. Our results highlight the importance of making more surface pCO2 observations in the area located east of the Azores Islands since air-sea CO2 fluxes there are poorly studied.The authors would like to thank those responsible for the two projects Proyecto Buque Escuela de Oceanografía 2011 (Research Project CTM 2009-08399-E/MAR) and the Malaspina Circumnavigation Expedition 2010 (Research Project Consolider-Ingenio, CSD 2008-00077), both funded by the Spanish Government. Their collaboration made this study possible. The authors would also like to thank J. Gómez-Enri and G. Navarro for their help with the satellite images.Peer reviewe

Not Only Toxic but Repellent: What Can Organisms’ Responses Tell Us about Contamination and What Are the Ecological Consequences When They Flee from an Environment?

The ability of aquatic organisms to sense the surrounding environment chemically and interpret such signals correctly is crucial for their ecological niche and survival. Although it is an oversimplification of the ecological interactions, we could consider that a significant part of the decisions taken by organisms are, to some extent, chemically driven. Accordingly, chemical contamination might interfere in the way organisms behave and interact with the environment. Just as any environmental factor, contamination can make a habitat less attractive or even unsuitable to accommodate life, conditioning to some degree the decision of organisms to stay in, or move from, an ecosystem. If we consider that contamination is not always spatially homogeneous and that many organisms can avoid it, the ability of contaminants to repel organisms should also be of concern. Thus, in this critical review, we have discussed the dual role of contamination: toxicity (disruption of the physiological and behavioral homeostasis) vs. repellency (contamination-driven changes in spatial distribution/habitat selection). The discussion is centered on methodologies (forced exposure against non-forced multi-compartmented exposure systems) and conceptual improvements (individual stress due to the toxic effects caused by a continuous exposure against contamination-driven spatial distribution). Finally, we propose an approach in which Stress and Landscape Ecology could be integrated with each other to improve our understanding of the threat contaminants represent to aquatic ecosystems.Versión del edito

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Curs 0: preparació per als estudis a l’EEBE

Aquest article presenta el desenvolupament i primers resultats d'ús d'un conjunt de cursos virtuals que pretenen proporcionar uns coneixements inicials bàsics de Matemàtiques, Física i !ímica als estudiants que accedeixen a estudis de grau a l'Escola d'Enginyeria de Barcelona Est (EEBE). Els cursos han estat desenvolupats sobre la plataforma Atenea (Moodle). El seu nucli el constitueixen un conjunt de materials per a autoaprenentatge que inclouen documents escrits, vídeos i tests d'autoavaluació. Els documents escrits i els vídeos corresponen tant a explicacions de teoria com a la resolució detallada d'exercicis. En el marc d'una prova pilot, els cursos, de seguiment voluntari durant el període transcorregut entre la matricula (mitjans de juliol) i l'inici de les classes (mitjans de setembre), van ser publicitats a tots els estudiants de nou accés del curs 2021-2022. Encara que la participació va ser més limitada del que s'esperava (únicament el 22% dels estudiants de nou accés es van inscriure), cal destacar que els estudiants que sí que van seguir els cursos van expressar majoritàriament una bona valoració dels mateixos (al respondre un qüestionari de satisfacció). Del desenvolupament dels cursos i de la realització de la prova pilot s'han obtingut unes quantes conclusions que també queden reflectides al final de l'article

Protective intraoperative ventilation with higher versus lower levels of positive end-expiratory pressure in obese patients (PROBESE): study protocol for a randomized controlled trial

Background: Postoperative pulmonary complications (PPCs) increase the morbidity and mortality of surgery in obese patients. High levels of positive end-expiratory pressure (PEEP) with lung recruitment maneuvers may improve intraoperative respiratory function, but they can also compromise hemodynamics, and the effects on PPCs are uncertain. We hypothesized that intraoperative mechanical ventilation using high PEEP with periodic recruitment maneuvers, as compared with low PEEP without recruitment maneuvers, prevents PPCs in obese patients. Methods/design The PRotective Ventilation with Higher versus Lower PEEP during General Anesthesia for Surgery in OBESE Patients (PROBESE) study is a multicenter, two-arm, international randomized controlled trial. In total, 2013 obese patients with body mass index ≥35 kg/m2 scheduled for at least 2 h of surgery under general anesthesia and at intermediate to high risk for PPCs will be included. Patients are ventilated intraoperatively with a low tidal volume of 7 ml/kg (predicted body weight) and randomly assigned to PEEP of 12 cmH2O with lung recruitment maneuvers (high PEEP) or PEEP of 4 cmH2O without recruitment maneuvers (low PEEP). The occurrence of PPCs will be recorded as collapsed composite of single adverse pulmonary events and represents the primary endpoint. Discussion To our knowledge, the PROBESE trial is the first multicenter, international randomized controlled trial to compare the effects of two different levels of intraoperative PEEP during protective low tidal volume ventilation on PPCs in obese patients. The results of the PROBESE trial will support anesthesiologists in their decision to choose a certain PEEP level during general anesthesia for surgery in obese patients in an attempt to prevent PPCs. Trial registration ClinicalTrials.gov identifier: NCT02148692. Registered on 23 May 2014; last updated 7 June 2016. Electronic supplementary material The online version of this article (doi:10.1186/s13063-017-1929-0) contains supplementary material, which is available to authorized users

Comparative effects of seawater acidification on microalgae: Single and multispecies toxicity tests

In order to gain knowledge about the potential effects of acidification in aquatic ecosystems, global change research based on microalgae as sentinel species has been often developed. However, these studies are limited to single species tests and there is still a research gap about the behaviour of microalgal communities under this environmental stressor. Thus, the aim of this study was to assess the negative effects of CO under an ecologically realistic scenario. To achieve this objective, two types of toxicity tests were developed; i) single toxicity tests and ii) multispecies toxicity tests, in order to evaluate the effects on each species as well as the interspecific competition. For this purpose, three microalgae species (Tetraselmis chuii, Phaeodactylum tricornutum and Nannochloropsis gaditana) were exposed to two selected pH levels (7.4, 6.0) and a control (pH 8.0). The pH values were choosen for testing different scenarios of CO enrichment including the exchange atmosphere-ocean (pH 7.4) and natural or anthropogenic sources of CO (pH 6.0). The effects on growth, cell viability, oxidative stress, plus inherent cell properties (size, complexity and autofluorescence) were studied using flow cytometry (FCM). Results showed that T. chuii was the most resistant species to CO enrichment with less abrupt changes in terms of cell density, inherent cell properties, oxidative stress and cell viability. Although P. tricornutum was the dominant species in both single and multispecies tests, this species showed the highest decrease in cell density under pH 6.0. Effects of competence were recorded in the multispecies control (pH 8) but this competence was eclipsed by the effects of low pH. The knowledge of biological interactions made by different microalgae species is a useful tool to extrapolate research data from laboratory to the field.The first author thanks the European Union for the doctoral fellowship (2014-0693/001-001-EMJD) and the funding of this work through the Erasmus Mundus Programme MACOMA. M. Sendra thanks Junta de Andalucía for her post-doctoral fellowship and M.R. de Orte thanks FAPESP for the post-doctoral scholarship under the process BEPE 2017/06686-2

Ingestion and bioaccumulation of polystyrene nanoplastics and their effects on the microalgal feeding of Artemia franciscana

9 pages, 6 figuresNanoplastics (NPs) have become one of the most serious environmental problems nowadays. The environmental issues linked to NPs are attributed to the effects after ingestion in marine organisms. Due to the incipient and controversial information about the effects of PS NPs on the feeding of organisms, the aim of this work is to assess (i) digestion dynamics of Artemia franciscana when exposed to PS NPs as the lowest concentration of PS NPs reported in toxicity test [0 (control), 0.006 and 0.6 mg·L-1] and possible interferences in the ingestion of microalgae and (ii) the accumulation and depuration of PS NPs by A. franciscana. Artemia were subjected to ingestion experiments [24 h and 3.5 h], in which the organisms were exposed to PS NPs or to PS NPs + microalgae. Post-exposure feeding (24 h exposure and 2 h feeding) and depuration (24 h exposure and 24 h of depuration) were also carried out. More than 90% of the PS NPs were ingested by Artemia and bioaccumulated in the mandible, stomach, gut, tail gut and appendages after 24 h. The ingestion of microalgae was not affected by the presence of the PS NPs. Data of post-exposure feeding indicated that Artemia previously exposed to plastic and/or microalgae presented similar microalgal ingestion (around 70%); the highest microalgal consumption (around 90%) was recorded in the treatment in which Artemia were previously starved (no plastic and no microalgae). The presence of PS NPs in the gut after the depuration experiments indicates that 24 h was not enough to eliminate the PS NPsMarta Sendra is grateful to CEI·MAR for their support of the CEIJ-C06.1 project. This research has been funded by the Spanish National Research Plan MINECO (CTM2016-75908-R). C.V.M. Araújo is grateful to the Spanish Ministry of Science, Innovation and Universities for a Juan de la Cierva contract (IJCI-2014-19318)Peer reviewe

Effect of adsorbed TiO2 nano-particles on aquatic organisms

Trabajo presentado en el 10th Iberian Congress on Environmental Contamination and Toxicology y el 7th Iberoamerican Congress on Environmental Contamination and Toxicology (CICTA 2015), celebrados en Vila Real (Portugal) del 14 al 17 de julio de 2015.Titanium dioxide nanoparticles (TiO2 NPs) are widely used in multitude of applications and present a potential risk due to the release to the marine and freshwater systems.TiO2 NPs have been demonstrated to be toxic to unicellular algae, as they can be adsorbed or internalized by the cells. TiO2 NPs could induce toxicity to aquatic organisms through various mechanisms including physical damage, shading effect, oxidative stress and/or internalization. Surface interactions, such as adsorption of NPs oncells, are important toxicity mechanisms. One of the deleterious could be the increase of cell weight due to the adsorption of NPs, which would sink the floating cells out from the photic zone. On the other hand, different NPs can present different surface properties and aggregation states in the NP-cell suspensions, leading to different NP-cell heteroagglomerations. Water chemistry, such as pH and ionic strength (IS), can also influence the aggregation state of NPs and will thus influence the NPs-Cell.Since sizes of both microorganism cells and NPs aggregates are within the scale of colloids, the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory can be applied to analyze the colloidal behavior of NPs and cells in water. In this study, different freshwater and seawater species of microalgae were chosen in order to investigate interactions between algal cells and TiO2 NPs and TiO2 bulk, as well assedimentation rate of NPs, exposed and non exposed,cells in the water column. This is the first study specifically designed in order to check the NP-cell heteroagglomeration and cells sedimentation in water systems. Our findings show new light on bio-nano interaction.N