403 research outputs found

    Damage Spreading in a Driven Lattice Gas Model

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    We studied damage spreading in a Driven Lattice Gas (DLG) model as a function of the temperature TT, the magnitude of the external driving field EE, and the lattice size. The DLG model undergoes an order-disorder second-order phase transition at the critical temperature Tc(E)T_c(E), such that the ordered phase is characterized by high-density strips running along the direction of the applied field; while in the disordered phase one has a lattice-gas-like behaviour. It is found that the damage always spreads for all the investigated temperatures and reaches a saturation value DsatD_{sat} that depends only on TT. DsatD_{sat} increases for TTc(E=)TT_c(E=\infty) and is free of finite-size effects. This behaviour can be explained as due to the existence of interfaces between the high-density strips and the lattice-gas-like phase whose roughness depends on TT. Also, we investigated damage spreading for a range of finite fields as a function of TT, finding a behaviour similar to that of the case with E=E=\infty.Comment: 13 pages, 7 figures. Submitted to "Journal of Statistical Mechanics: Theory and Experiment

    Toward understanding calmodulin plasticity by molecular dynamics

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    Aim: Calmodulin interacts in many different ways with its ligands. We aim to shed light on its plasticity analysing the changes followed by the linker region and the relative position of the lobes using conventional Molecular Dynamics (cMD), accelerated MD (aMD) and scaled MD (sMD). Materials & Methods: Three different structures of calmodulin are compared, obtaining a total of 2.5 μs of molecular dynamics, which have been analysed using the principal component analysis and clustering methodologies Results: sMD simulations reach conformations that cMD is not able to, without compromising the stability of the protein. On the other hand, aMD requires optimization of the setup parameters to be useful. Conclusion: SMD is useful to study flexible proteins, highlighting those factors that justify its promiscuit

    Plant Traits and Phylogeny Predict Soil Carbon and Nutrient Cycling in Mediterranean Mixed Forests

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    Soil functioning is closely linked to the interactions between biological communities with the physical environment. Yet, the impact of plant community attributes on metabolic processes promoting soil nutrient cycling remains largely unknown. We hypothesized that the plant community acts as a regulating agent of nutrient mobilization in soils according to the phylogenetic and morpho-functional traits of plant species of which it is composed. Rhizosphere soils were collected in autumn and spring under 32 tree and shrub species in two Mediterranean mixed forests (four plots in each) located in southern Spain, and nine soil enzymatic activities related to C, N and P mobilization were assessed. Phylogeny and morpho-functional traits of plant species were recorded and their imprint in soil enzymatic activities across forests was determined. The results showed a plant phylogenetic signal for N mobilization in both forests, while it varied across forests for non-labile C and P mobilization. The plant phylogenetic signals were primarily driven by lineages that diversified through the Miocene, about 25 Myr ago. In addition, leaf traits and plant’s mycorrhizal type explained soil enzymatic activities independently from phylogeny. C and P mobilization increased under ectomycorrhizal plants, whilst enhanced N mobilization did occur under arbuscular mycorrhizal ones. The plant community composition led to a different carbon and nutrient mobilization degree, which in turn was mediated by distinct microbial communities mirroring differentiated resource-acquisition strategies of plants. Our results highlight the role of plant traits and mycorrhizal interactions in modulating carbon and nutrient cycling in Mediterranean mixed forest soils.CRUE-CSIC Springer Natur

    The Contribution of Cytosolic Group IVA and Calcium-Independent Group VIA Phospholipase A2s to Adrenic Acid Mobilization in Murine Macrophages

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    Producción CientíficaAdrenic acid (AA), the 2-carbon elongation product of arachidonic acid, is present at significant levels in membrane phospholipids of mouse peritoneal macrophages. Despite its abundance and structural similarity to arachidonic acid, very little is known about the molecular mechanisms governing adrenic acid mobilization in cells of the innate immune system. This contrasts with the wide availability of data on arachidonic acid mobilization. In this work, we used mass-spectrometry-based lipidomic procedures to define the profiles of macrophage phospholipids that contain adrenic acid and their behavior during receptor activation. We identified the phospholipid sources from which adrenic acid is mobilized, and compared the data with arachidonic acid mobilization. Taking advantage of the use of selective inhibitors, we also showed that cytosolic group IVA phospholipase A2 is involved in the release of both adrenic and arachidonic acids. Importantly, calcium independent group VIA phospholipase A2 spared arachidonate-containing phospholipids and hydrolyzed only those that contain adrenic acid. These results identify separate mechanisms for regulating the utilization of adrenic and arachidonic acids, and suggest that the two fatty acids may serve non-redundant functions in cells.Ministerio de Economía, Industria y Competitividad (grant SAF2016-80883-R

    Transcriptome Analysis and Intraspecific Variation in Spanish Fir (Abies pinsapo Boiss.)

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    Spanish fir (Abies pinsapo Boiss.) is an endemic, endangered tree that has been scarcely investigated at the molecular level. In this work, the transcriptome of Spanish fir was assembled, providing a large catalog of expressed genes (22,769), within which a high proportion were full-length transcripts (12,545). This resource is valuable for functional genomics studies and genome annotation in this relict conifer species. Two intraspecific variations of A. pinsapo can be found within its largest population at the Sierra de las Nieves National Park: one with standard green needles and another with bluish-green needles. To elucidate the causes of both phenotypes, we studied different physiological and molecular markers and transcriptome profiles in the needles. “Green” trees showed higher electron transport efficiency and enhanced levels of chlorophyll, protein, and total nitrogen in the needles. In contrast, needles from “bluish” trees exhibited higher contents of carotenoids and cellulose. These results agreed with the differential transcriptomic profiles, suggesting an imbalance in the nitrogen status of “bluish” trees. Additionally, gene expression analyses suggested that these differences could be associated with different epigenomic profiles. Taken together, the reported data provide new transcriptome resources and a better understanding of the natural variation in this tree species, which can help improve guidelines for its conservation and the implementation of adaptive management strategies under climatic change.This research was funded by research projects “Genómica funcional del pinsapo” and “Genómica del pinsapo: Estudios estructurales y funcionales” (grant numbers UMA18-FEDERJA-018 and P20-00507-R, funded by Junta de Andalucía, PAIDI) and “Modulators of adaptive capacity to climate change in forests: integration from the landscape to the gene/transcriptome in relict mountain conifers (CoMoReAdapt)” (grant number CGL2013-48843-C2-1-R, funded by the Spanish Ministry of Economy and Competitiveness, National Program for R + D+i). Partial funding for open access charge: Universidad de Málag

    Modelling and cooling power control of an absorption machine

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    [Resumen] El artículo presenta el modelado y control de la potencia frigorífica de una máquina de absorción solar, la cual se supone que está abastecida con un reservorio de energía térmica, utilizada para sistemas de climatización. Se pretende satisfacer la demanda de frío de una instalación. El modelado de cada uno de los componentes ha sido implementado en Simulink, con el objetivo de obtener la simulación completa de la planta. En el simulador, el sistema de refrigeración propuesto presenta lazos de control para mantener las variables de salida de los caudales y temperaturas en referencias establecidas. Finalmente, se presentan los resultados de la simulación que muestran el comportamiento de la planta y que avalan el buen funcionamiento del sistema de control.[Abstract] The article presents the modeling and control of the cooling capacity of a absorption machine feeded by a energy reservoir, used for air conditioning systems. It is intended to satisfy the cooling demand of an installation. The modeling of each of the components has been implemented in Simulink, in order to obtain the complete simulation of the plant. In the simulator, the proposed refrigeration system presents control loops to maintain the output variables of the flow rates and temperatures in established references. Finally, the results of the simulation are presented, which show the behavior of the plant and support the good performance of the control system.Junta de Andalucía; US-138150

    The relationship between physician and cancer patient when initiating adjuvant treatment and its association with sociodemographic and clinical variables

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    Purpose The aim of this study was to analyze differences in physician and patient satisfaction in shared decision-making (SDM); patients' emotional distress, and coping in subjects with resected, non-metastatic cancer. Methods 602 patients from 14 hospitals in Spain were surveyed. Information was collected regarding physician and patient satisfaction with SDM, participants' emotional distress and coping, as well as patient sociodemographic and clinical characteristics by means of specific, validated questionnaires. Results Overall, 11% of physicians and 19% of patients were dissatisfied with SDM; 22% of patients presented hopelessness or anxious preoccupation as coping strategies, and 56% presented emotional distress. By gender, female patients showed a higher prevalence of dissatisfaction with SDM (23 vs 14%), anxious preoccupation (26 vs 17%), and emotional distress (63 vs 44%) than males. Hopelessness was more prevalent in individuals with stage III disease than those with stages I-II (28 vs 18%). Conclusion Physicians must be mindful of the importance of emotional support and individual characteristics when communicating treatment options, benefits, and adverse effects of each alternative to oncological patients

    HIV-1 diagnosis using dried blood spots from patients in Kinshasa, DRC: a tool to detect misdiagnosis and achieve World Health Organization 2030 targets

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    Introduction: Currently, only 54% of the population of the Democratic Republic of the Congo (DRC) know their HIV status. The aim of this study was to detect HIV misdiagnosis from rapid diagnostic tests (RDT) and to evaluate serological immunoassays using dried blood spots (DBS) from patients in Kinshasa, DRC. Methods: Between 2016 and 2018, 365 DBS samples were collected from 363 individuals and shipped to Spain. The samples were from people with a new HIV positive ( n = 123) or indeterminate ( n = 23) result, known HIV-positive patients ( n = 157), and a negative control group ( n = 62). HIV serology was performed using Elecsys HIV combi PT (Roche), VIDAS HIV Duo Quick (BioMerieux), and Geenius (BioRad). In addition, HIV RNA detection was performed in all samples using the COBAS AmpliPrep/COBAS Taqman HIV-1 Test 2.0 (Roche). Results: Overall, 272 samples were found to be positive and 93 to be negative for HIV serology. The sensitivity was 100% for both Elecsys and VIDAS techniques, but specificity was slightly higher for the VIDAS test: 100% (96.1-100%) vs 98.9% (94.1-99.9%). Of the 23 indeterminate cases using RDT, only three cases were true-positives with a detectable viral load. Eleven samples out of the 280 classified as positive by RDT corresponded to nine patients who had received a false diagnosis of HIV through RDT (3.9%); six of them had been on antiretroviral therapy for at least 2 years. Conclusions: Elecsys HIV combi PT and VIDAS HIV Duo Quick immunoassays showed high sensitivity and specificity when using DBS. RDT-based serological diagnosis can lead to HIV misdiagnosis with personal and social consequences in sub-Saharan Africa. (c) 2021 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/

    Immune surveillance for six vaccinable pathogens using paired plasma and dried blood spots in HIV infected and uninfected children in Kinshasa

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    Child vaccination reduces infant mortality rates. HIV-infected children present higher risk of diseases than non-infected. We report the protection coverage rates for 6 vaccine-preventable diseases in a paediatric population from the Democratic Republic of the Congo (DRC) and the impact of HIV infection, providing the first data on the validity of dried blood samples (DBS) to monitor the immune protection. During 2016-2018 DBS from 143 children/adolescents were collected in Kinshasa (DRC), being 52 HIV-infected. Forty-two had a paired plasma sample. Protective IgG was quantified (VirClia-IgG,VIRCELL) to obtain the optimal cut-off in IgG detection in DBS. ROC curves were generated with R software and statistical analyses with Stata. Protective IgG levels varied across pathogens, not reaching herd immunity. HIV-infected presented lower vaccine protection than uninfected for all analyzed pathogens, except rubella, with statistically significant differences for measles (30.8% vs. 53.8%; p = 0.008) and tetanus (3.8% vs. 22%; p = 0.0034). New cut-offs were calculated when using DBS to improve test performance. We reinforce the necessity to increase pediatric vaccination coverage in Kinshasa, especially in HIV seropositive, with less capacity to maintain adequate antibody levels. DBS were useful to monitor vaccination coverage in seroprevalence studies in resource-limited settings, after optimizing the cut-off value for each pathogen
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