The Myth of The Annular Lipids

In the early 1970s, the existence of a “lipid annulus” stably surrounding the individual intrinsic protein molecules was proposed by several authors. They referred to a number of lipid molecules in slow exchange with the bulk lipid in the bilayer, i.e., more or less protein-bound, and more ordered than the bulk lipid. The annular lipids would control enzyme activity. This idea was uncritically accepted by most scientists working with intrinsic membrane proteins at the time, so that the idea operated like a myth in the field. However, in the following decade, hard spectroscopic and biochemical evidence showed that the proposed annular lipids were not immobilized for a sufficiently long time to influence enzyme or transporter activity, nor were they ordered by the protein. Surprisingly, forty years later, the myth survives, and the term ‘annular lipid’ is still in use, in a different, but even more illogical sense.This research was funded in part by the Spanish Ministerio de Ciencia e Innovación (MCI), Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) (grant No. PID2021-124461NB-I00), by the Basque Government (grant No. IT1625-22), by Fundación Ramón Areces (CIVP20A6619), by Fundación Biofísica Bizkaia, and by the Basque Excellence Research Centre (BERC) program of the Basque Government

Capsaicin affects the structure and phase organization of phospholipid membranes

AbstractCapsaicin is a natural compound with pharmacological and toxicological effects, which given its hydrophobicity, can influence the structure of membranes. The interaction of capsaicin with model membranes of dipalmitoylphosphatidylcholine and dielaidoylphosphatidylethanolamine has been studied by using differential scanning calorimetry, fluorescent probe spectroscopy and 31P-nuclear magnetic resonance. Capsaicin remarkably affects the phase transition of dipalmitoylphosphatidylcholine, shifting the transition temperature to lower values, and giving rise, at relatively high capsaicin concentrations, to the appearance of two peaks in the thermogram. These peaks may correspond to separated phases as indicated by the partial phase diagram. Whereas capsaicin did not affect the fluorescence polarization of the probes diphenylhexatriene and trimethylammonium-diphenylhexatriene, it clearly affected that of the probe 2-anthroyloxystearic acid, indicating that the perturbation produced by capsaicin on the membrane would be mainly at the position where this fluorophore is located. On the other hand, capsaicin, at relatively low concentrations, gives rise to immiscible phases in the presence of dielaidoylphoshatidylethanolamine and decrease the temperature of the lamellar to hexagonal HII phase transition. At concentrations of capsaicin higher than 0.3 mol fraction, isotropic phases were detected. The possible implications of the effects of capsaicin on biological membranes are discussed

Influencia de algunas variables en el ensayo a compresión de probetas testigo en un hormigón autocompactante

La estimación de la resistencia a compresión a través de la evaluación de probetas testigo depende de numerosas variables, entre ellas, el diámetro de la probeta testigo, la dirección de extracción en relación con la dirección del hormigonado, el estado de humedad de la probeta testigo en el momento de ser ensayada, la esbeltez de la probeta testigo, la armadura embebida en la probeta testigo y la edad del hormigón investigado. El objetivo de este trabajo experimental ha sido evaluar, para un hormigón autocompactante, el efecto que presentan algunas de estas variables en el resultado de la resistencia a compresión de las probetas testigo. Estos efectos pueden ser muy diferentes de los que ocurren en el hormigón vibrado, debido a que no existe en este caso un procedimiento específico para la compactación de las probetas moldeadas. Igualmente se han analizado los posibles factores de corrección utilizados en la estimación de la resistencia a compresión de la probeta moldeada a través de la resistencia a compresión de la probeta testigo. Para ello se han fabricado 30 bloques de 50x50x100 cm en HAC cubriendo un amplio rango de resistencias (20 MPa - 80 MPa), de los cuales se extrajeron un total de 360 probetas testigo. Paralelamente a la ejecución de los bloques se han fabricado 90 probetas cilíndricas de 15 30 cm que posteriormente fueron ensayadas a compresión a la misma edad que las probetas testigo (28 días). Los resultados muestran que algunas de las variables incíden de forma muy diferente en estos hormigones que en los hormigones convencionales, en especial la dirección de extracción y el coeficiente de paso para considerar la resistencia en probeta moldeada

An Evolutionary Artificial Neural Network approach for spatio-temporal wave height time series reconstruction

This paper proposes a novel methodology for recovering missing time series data, a crucial task for subsequent Machine Learning (ML) analyses. The methodology is specifically applied to Significant Wave Height (SWH) time series in the field of marine engineering. The proposed approach involves two phases. Firstly, the SWH time series for each buoy is independently reconstructed using three transfer function models: regression-based, correlation-based, and distance-based. The distance-based transfer function exhibits the best overall performance. Secondly, Evolutionary Artificial Neural Networks (EANNs) are utilised for the final recovery of each time series, using as inputs highly correlated buoys that have been intermediately recovered. The EANNs are evolved considering two metrics, the novel squared error relevance area, which balances the importance of extreme and around-mean values, and the well-known mean squared error. The study considers SWH time series data from 15 buoys in two coastal zones in the United States. The results demonstrate that the distance-based transfer function is generally the best transfer function, and that EANNs outperform a range of state-of-the-art ML techniques in 12 out of the 15 buoys, with a number of connections comparable to linear models. Furthermore, the proposed methodology outperforms the two most popular approaches for time series reconstruction, BRITS and SAITS, for all buoys except one. Therefore, the proposed methodology provides a promising approach, which may be applied to time series from other fields, such as wind or solar energy farms in the field of green energy

Gamifying the Classroom for the Acquisition of Skills Associated with Machine Learning: A Two-Year Case Study

Machine learning (ML) is the field of science that combines knowledge from artificial intelligence, statistics and mathematics intending to give computers the ability to learn from data without being explicitly programmed to do so. It falls under the umbrella of Data Science and is usually developed by Computer Engineers becoming what is known as Data Scientists. Developing the necessary competences in this field is not a trivial task, and applying innovative methodologies such as gamification can smooth the initial learning curve. In this context, communities offering platforms for open competitions such as Kaggle can be used as a motivating element. The main objective of this work is to gamify the classroom with the idea of providing students with valuable hands-on experience by means of addressing a real problem, as well as the possibility to cooperate and compete simultaneously to acquire ML competences. The innovative teaching experience carried out during two years meant a great motivation, an improvement of the learning capacity and a continuous recycling of knowledge to which Computer Engineers are faced to

Towards an integrated approach for monitoring the effects of chemical contaminants in the Spanish coastal Mediterranean waters

Oral communicationIn the past twelve years, chemical monitoring surveys in Spanish Mediterranean coastal waters have developed from the use of native mussels to an integrated sampling of native and caged mussels, fish (red mullet) and sediment. In addition, the application of biological effect measurements (using biomarkers and bioassays) in the same matrices is being gradually arising. So far, biological measurements have comprised a suite of biomarkers in fish (EROD, Ala-D and AChE activities, Metallothionein content, DNA integrity and micronuclei abnormalities) and in mussels (Stress on Stress, lysosomal membrane stability, Metallothionein content, Micronuclei frequency, AChE and antioxidant enzymes) as well as the sea urchin embryotoxicity test with Paracentrotus lividus in sediment elutriates. Most of the driving forces behind these changes came from recommendations and Standard Operation Practices provided by expert organizations as MED POL, ICES, and OSPAR, and these changes have considerably increased the costs of monitoring. However, higher costs of intensive monitoring activities will allow contributing to a more realistic assessment of the quality and health status of the marine ecosystem. For this purpose quality assurance and the development of assessment criteria for the selected methods is a prerequisite. These requirements are necessary to meet national and international obligations (EU-MSFD, EU-WFD). Here, we present and discuss the integrated chemical-biological effect approach that is currently being proposed for implementation in the Spanish Mediterranean monitoring programme 2010-2012. The selected biological measurements, the assessment criteria obtained so far and quality assurance processes are discussed in terms of feasibility.The Spanish Mediterranean Biomonitoring Programs of chemical contamination (BMCW and BMIS programs) are conducted by the Instituto Español de Oceanografía (IEO) under the responsibility of the Ministry of Environment (MEDPOLIEO Project in 2006 and 2-ESMARME Project in 2010-2012)

Biomonitoring strategy to assess the effects of chemical pollution along the Iberian Mediterranean Coast: Present state and future development

oral presentationSince 2001, the Oceanographic Centre of Murcia (Spanish Institute of Oceanography, IEO) started to include selected biomarkers within the chemical pollution monitoring activities conducted along the Iberian Mediterranean coast. The main objectives of this biomonitoring programme are: (1) the determination of spatial distribution and temporal trends of chemical pollution in coastal and reference areas; (2) to seek evidence of detrimental biological effects and assess them over time. Sediment samples, feral fish (Mullus barbatus) and wild mussels (Mytilus galloprovincialis) are analysed yearly for selected pollutants (trace metals, organochlorinated compounds and polycyclic aromatic hydrocarbons) and selected biomarkers are measured in fish and/or mussels (EROD activity, metallothionein content, micronuclei frequency, genotoxic damages, acetylcholinesterase, stress on stress and lysosomal membrane stability). An integrated chemical-biological effect assessment approach is being conducted at four selected areas since 2006. Due to its geographical location, Spain contributes to both the CEMP and MEDPOL programmes and our future strategy will be focused to achieve the harmonization of criteria among different programmes and to meet the monitoring requirements in a cost-effective and cost-efficient way. The general strategy and methods of this biomonitoring programme together with some preliminary results and future development (use of caged mussels) are described and discussed.This Biomonitoring Programme was initially funded by the Spanish Institute of Oceanography, IEO (projects BIOMEJIMED I, BIOMEJIMED II and BIOMEJIMED III). Since November 2005 it is funded by Ministry of Environment (MEDPOLIEO project)

Deciphering the Role and Signaling Pathways of PKCα in Luminal A Breast Cancer Cells.

Protein kinase C (PKC) comprises a family of highly related serine/threonine protein kinases involved in multiple signaling pathways, which control cell proliferation, survival, and differentiation. The role of PKCα in cancer has been studied for many years. However, it has been impossible to establish whether PKCα acts as an oncogene or a tumor suppressor. Here, we analyzed the importance of PKCα in cellular processes such as proliferation, migration, or apoptosis by inhibiting its gene expression in a luminal A breast cancer cell line (MCF-7). Differential expression analysis and phospho-kinase arrays of PKCα-KD vs. PKCα-WT MCF-7 cells identified an essential set of proteins and oncogenic kinases of the JAK/STAT and PI3K/AKT pathways that were down-regulated, whereas IGF1R, ERK1/2, and p53 were up-regulated. In addition, unexpected genes related to the interferon pathway appeared down-regulated, while PLC, ERBB4, or PDGFA displayed up-regulated. The integration of this information clearly showed us the usefulness of inhibiting a multifunctional kinase-like PKCα in the first step to control the tumor phenotype. Then allowing us to design a possible selection of specific inhibitors for the unexpected up-regulated pathways to further provide a second step of treatment to inhibit the proliferation and migration of MCF-7 cells. The results of this study suggest that PKCα plays an oncogenic role in this type of breast cancer model. In addition, it reveals the signaling mode of PKCα at both gene expression and kinase activation. In this way, a wide range of proteins can implement a new strategy to fine-tune the control of crucial functions in these cells and pave the way for designing targeted cancer therapies.Work in Murcia was supported by grants BFU2017-87222-P (MICINN, Spain-FEDER) to S.C.-G. and J.C.G.-F. and Fundación Séneca Region de Murcia 20885/PI/18 to S.C.-G.S

Assessment of oceanographic services for the monitoring of highly anthropised coastal lagoons: The Mar Menor case study

Ocean monitoring systems are designed for continuous monitoring to track their evolution and anticipate environmental issues. However, they are often based on IoT systems that offer little spatial coverage and are hard to maintain. Satellite remote sensing offers good geographical coverage but they also face several challenges to become a monitoring system. This paper introduces an easy-to-use software tool to crawl water-quality data from up to 6 satellite instruments from the ESA and NASA. Particularly, Chl-a data is deeply analyzed in terms of reliability and data coverage for a highly anthropised coastal lagoon (Mar Menor, Spain), where serious socio-environmental issues are happening. Our results show a good linear correlation between in situ data and SRS data, reaching values close to 0.9, and stating the relevance of organic matter inputs from ephemeral streams in Chl-a concentrations. Moreover, temporal granularity is increased from 5 to 1.5 days by combining SRS sources.Preprin