Calcium Looping with Enhanced Sorbent Performance: Experimental Testing in A Large Pilot Plant

AbstractPostcombustion CO2 capture by Calcium Looping (CaL) has been successfully carried out for more than 700 hours in a 1.7 MWth continuous pilot facility in La Pereda (Spain). The pilot is equipped with two interconnected circulating fluidized bed reactors: a CO2 carbonator, where CaCO3 is formed when CO2 is captured from a combustion flue gas in contact with fine particles of CaO, and an oxy-fired calciner, where a highly concentrated stream of CO2 is generated by decomposing the CaCO3 formed in the carbonator. CaL is a technology that has the potential to achieve a substantial reduction in the cost of CO2 capture because of the capability to recover waste heat and generate more power from the additional fuel fired in the calciner. However, one of the weaknesses of CaL systems is the rapid deactivation of the sorbent. The EU “ReCaL” project (http://recal-project.eu/) aims to develop a robust and simple reactivation process to stabilize sorbent activity in CaL systems, based on the thermodynamic and kinetic ability of the sorbent to increase its CaCO3 conversion under enhanced carbonation conditions. This paper presents a first attempt to demonstrate the concept at the scale of the La Pereda 1.7 MWth pilot plant. It describes the redesign and retrofitting exercise conducted in the pilot and discusses the initial experimental results achieved when one of the loop seals is used as “recarbonator” reactor (putting a small flow of pure CO2 in contact with partially carbonated particles arriving from the carbonator). The findings of this study suggest that recarbonation could be responsible for about 100% increase in the average CO2 carrying capacity of the material used in the CO2 capture step taking place in the carbonator. This could allow CaL systems to operate with very low limestone make-up flow requirements, making this emerging capture technology more competitive

Mechanisms involved in drought stress tolerance triggered by rhizobia strains in wheat

Rhizobium spp. is a well-known microbial plant biostimulant in non-legume crops, but little is known about the mechanisms by which rhizobia enhance crop productivity under drought stress. This work analyzed the mechanisms involved in drought stress alleviation exerted by Rhizobium leguminosarum strains in wheat plants under water shortage conditions. Two (LBM1210 and LET4910) of the four R. leguminosarum strains significantly improved the growth parameters (fresh and dry aerial weight, FW and DW, respectively), chlorophyll content, and relative water content (RWC) compared to a non-inoculated control under water stress, providing values similar to or even higher for FW (+4%) and RWC (+2.3%) than the non-inoculated and non-stressed control. Some other biochemical parameters and gene expression explain the observed drought stress alleviation, namely the reduction of MDA, H2O2 (stronger when inoculating with LET4910), and ABA content (stronger when inoculating with LBM1210). In agreement with these results, inoculation with LET4910 downregulated DREB2 and CAT1 genes in plants under water deficiency and upregulated the CYP707A1 gene, while inoculation with LBM1210 strongly upregulated the CYP707A1 gene, which encodes an ABA catabolic enzyme. Conversely, from our results, ethylene metabolism did not seem to be involved in the alleviation of drought stress exerted by the two strains, as the expression of the CTR1 gene was very similar in all treatments and controls. The obtained results regarding the effect of the analyzed strains in alleviating drought stress are very relevant in the present situation of climate change, which negatively influences agricultural production.This project has been financially supported by European Commission - BBI JU project “Bio-based FERtilising products as the best practice for agricultural management SusTainability (BFERST)”. H2020-BBI-JTI-2018, Grant agreement ID: 837583. NO-L was granted a fellowship from the FPU program by the Spanish Ministry of Education with code (FPU 17/04201)

Maximization of Regional probabilities using Optimal Surface Graphs: Application to Carotid Artery Segmentation in MRI

__Purpose__ We present a segmentation method that maximizes regional probabilities enclosed by coupled surfaces using an Optimal Surface Graph (OSG) cut approach. This OSG cut determines the globally optimal solution given a graph constructed around an initial surface. While most methods for vessel wall segmentation only use edge information, we show that maximizing regional probabilities using an OSG improves the segmentation results. We applied this to automatically segment the vessel wall of the carotid artery in magnetic resonance images. __Methods__ First, voxel-wise regional probability maps were obtained using a Support Vector Machine classifier trained on local image features. Then the OSG segments the regions which maximizes the regional probabilities considering smoothness and topological constraints. __Results__ The method was evaluated on 49 carotid arteries from 30 subjects. The proposed method shows good accuracy with a Dice wall overlap of 74:1%+-4:3%, and significantly outperforms a published method based on an OSG using only surface information, the obtained segmentations using voxel-wise classification alone, and another published artery wall segmentation method based on a deformable surface model. Intra-class correlations (ICC) with manually measured lumen and wall volumes were similar to those obtained between observers. Finally, we show a good reproducibility of the method with ICC = 0:86 between the volumes measured in scans repeated within a short time interval. __Conclusions__ In this work a new segmentation method that uses both an OSG and regional probabilities is presented. The method shows good segmentations of the carotid artery in MRI and outperformed another segmentation method that uses OSG and edge information and the voxel-wise segmentation using the probability maps

Evaluación de los ingresos, empleo, diversidad y captura de carbono en algunas fincas de la cuenca del río la vieja

En 18 fincas del municipio de Alcalá se evaluaron ingresos, empleo, diversidad y captura de carbono. Esto se realizó por medio del estudio de perfil de pobreza que identificó el tipo de empleo y el acceso a los recursos, flujos de caja para el primer semestre de 2005, datos sobre macrofauna edáfica y almacenamiento de carbono en el suelo, y conocimiento de los propietarios o administradores sobre proyectos institucionale

The MAL protein is crucial for proper membrane condensation at the ciliary base, which is required for primary cilium elongation

The base of the primary cilium contains a zone of condensed membranes whose importance is not known. Here, we have studied the involvement of MAL, a tetraspanning protein that exclusively partitions into condensed membrane fractions, in the condensation of membranes at the ciliary base and investigated the importance of these membranes in primary cilium formation. We show that MAL accumulates at the ciliary base of epithelial MDCK cells. Knockdown of MAL expression resulted in a drastic reduction in the condensation of membranes at the ciliary base, the percentage of ciliated cells and the length of the cilia, but did not affect the docking of the centrosome to the plasma membrane or produce missorting of proteins to the pericentriolar zone or to the membrane of the remaining cilia. Rab8 (for which there are two isoforms, Rab8A and Rab8b), IFT88 and IFT20, which are important components of the machinery of ciliary growth, were recruited normally to the ciliary base of MAL-knockdown cells but were unable to elongate the primary cilium correctly. MAL, therefore, is crucial for the proper condensation of membranes at the ciliary base, which is required for efficient primary cilium extensionThis work was supported by the Ministerio de Economıa y Competitividad, Spain [grant numbers BFU2012-32532 and CONSOLIDER COAT CSD2009-00016 to M. A.A.]. G.A. was supported by the Amarouto Program for senior researchers from the Comunidad Autónoma de Madri

Comparison of CT and CMR for detection and quantification of carotid artery calcification:the Rotterdam Study

Background: Carotid artery atherosclerosis is an important risk factor for stroke. As such, quantitative imaging of carotid artery calcification, as a proxy of atherosclerosis, has become a cornerstone of current stroke research. Yet, population-based data comparing the computed tomography (CT) and cardiovascular magnetic resonance (CMR) for the detection and quantification of calcification remain scarce. Methods: A total of 684 participants from the population-based Rotterdam Study underwent both a CT and CMR of the carotid artery bifurcation to quantify the amount of carotid artery calcification (mean interscan interval: 4.9 ± 1.2 years). We investigated the correlation between the amount of calcification measured on CT and CMR using Spearman’s correlation coefficient, Bland-Altman plots, and linear regression. In addition, using logistic regression modeling, we assessed the association of CT and CMR based calcification volumes with a history of stroke. Results: We found a strong correlation between CT and CMR based calcification volumes (Spearman’s correlation coefficient:0.86, p-value ≤0.01). Bland-Altman analyses showed a good agreement, though CT based calcification volumes were systematically larger. Finally, calcification volume assessed with either imaging modality was associated with a history of stroke with similar effect estimates (odds ratio (OR) per 1-SD increase in calcification volume: 1.52 (95% CI:1.00;2.30) for CT, and 1.47 (95% CI:1.01;2.14) for CMR. Conclusion: CT based and CMR based volumes of carotid artery calcification are highly correlated, but CMR based calcification is systematically smaller than those obtained with CT. Despite this difference, both provide comparable information with regard to a history of stroke. Electronic supplementary material The online version of this article (doi:10.1186/s12968-017-0340-z) contains supplementary material, which is available to authorized users

Dietary supplementation with vitamins C and E prevents downregulation of endothelial NOS expression in hypercholesterolemia in vivo and in vitro

Impaired endothelium-dependent vasodilation has been associated with decreased NO bioavailability in hypercholesterolemia. This study aimed to determine whether antioxidant vitamins C and E could improve hypercholesterolemia-derived endothelial dysfunction in the porcine model, and whether observed in vivo results could be reproduced in vitro by incubation of coronary endothelial cells (EC) in the presence of native low-density lipoproteins (LDL). Adult mini-pigs were fed standard (C), cholesterol rich (HC) or cholesterol rich diet supplemented with vitamins C and E (HCV). Endothelium-dependent blood flow increase in response to acetylcholine was determined. Endothelial nitric oxide synthase (eNOS) expression was measured in arterial samples and in EC incubated with LDL isolated from porcine plasma. Vasomotor response to acetylcholine in HC was significantly lower (P<0.05) than control and HCV. There was a significant (P<0.05) decrease in eNOS immunoreactivity in HC, compared with HCV and control. Native LDL from HC, but not from HCV, induced a significant decrease in eNOS expression. Vitamins C and E treatment improved the endothelium-dependent vasomotor capacity and prevented decreased expression of eNOS in hypercholesterolemic pigs. A similar effect could be demonstrated in vitro, by incubation of EC with native LDL, suggesting that the effect of physiologically-modified LDL on eNOS could have a role in recovering vascular function

Carotid artery lumen segmentation in 3D free-hand ultrasound images using surface graph cuts

We present a new approach for automated segmentation of the carotid lumen bifurcation from 3D free-hand ultrasound using a 3D surface graph cut method. The method requires only the manual selection of single seed points in the internal, external, and common carotid arteries. Subsequently, the centerline between these points is automatically traced, and the optimal lumen surface is found around the centerline using graph cuts. To refine the result, the latter process was iterated. The method was tested on twelve carotid arteries from six subjects including three patients with a moderate carotid artery stenosis. Our method successfully segmented the lumen in all cases. We obtained an average dice overlap with respect to a manual segmentation of 84% for healthy volunteers. For the patient data, we obtained a dice overlap of 66.7%

Trypanosoma cruzi infection, discrete typing units and feeding sources among Psammolestes arthuri (Reduviidae: Triatominae) collected in eastern Colombia

Background: Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi, and is transmitted by hematophagous insects of the family Reduviidae. Psammolestes arthuri is a sylvatic triatomine distributed in Colombia and Venezuela which feeds on birds and there are a few studies that have reported Ps. arthuri naturally infected with T. cruzi. In Colombia, Ps. arthuri has been found in dwellings, making it important to evaluate its possible role in the T. cruzi transmission cycle. We aimed to evaluate the presence of T. cruzi and feeding sources of Ps. arthuri to elucidate new possible scenarios of T. cruzi transmission in the country. Methods: A total of 60 Ps. arthuri were collected in Arauca and Casanare, Colombia. We detected and genotyped T. cruzi and identified feeding sources. The frequency of the presence of T. cruzi was obtained and compared with different eco-epidemiological variables. Multiple correspondence analysis was conducted to explore associations between eco-epidemiological variables and the presence of T. cruzi; with these results, a logistic regression was used to determine statistical associations. Results: The infection rate of T. cruzi was 70.7% and was mostly associated with insect stage, sex, bird nest and feeding source. Regarding discrete typing units (DTUs), TcI was found in 54.7% samples, of which 21.7% (5/23) were TcI Dom , 52.1% (12/23) had mixed infection (TcI Dom -TcI Sylv ), and single infection with TcI Sylv was not detected. Mixed infections (TcI/TcII-TcVI) were found in 9.52% (4/42) of the samples; of these, 14.2% (6/42) were TcII-TcVI. A total of 15 feeding sources were identified and the most frequent were: Cranioleuca baroni (35.85%), Homo sapiens (26.42%), Thraupis episcopus (11.32%) and Serinus albogularis (3.77%). Conclusions: Although Ps. arthuri is mainly ornithophilic, this species may be feeding on other animals that can be infected with T. cruzi, possibly playing a role maintaining the zoonotic cycle of the parasite. Further studies with molecular techniques and wider sampling are needed to improve information regarding infection rates, ecotopes and habits with the aim of evaluating whether Ps. arthuri could be a potential T. cruzi vector. © 2019 The Author(s)