Historical Evolution of theWave Resource and Energy Production off the Chilean Coast over the 20th Century

The wave energy resource in the Chilean coast shows particularly profitable characteristics for wave energy production, with relatively high mean wave power and low inter-annual resource variability. This combination is as interesting as unusual, since high energetic locations are usually also highly variable, such as the west coast of Ireland. Long-term wave resource variations are also an important aspect when designing wave energy converters (WECs), which are often neglected in resource assessment. The present paper studies the long-term resource variability of the Chilean coast, dividing the 20th century into five do-decades and analysing the variations between the different do-decades. To that end, the ERA20C reanalysis of the European Centre for Medium-Range Weather Forecasts is calibrated versus the ERA-Interim reanalysis and validated against buoy measurements collected in different points of the Chilean coast. Historical resource variations off the Chilean coast are compared to resource variations off the west coast in Ireland, showing a significantly more consistent wave resource. In addition, the impact of historical wave resource variations on a realistic WEC, similar to the Corpower device, is studied, comparing the results to those obtained off the west coast of Ireland. The annual power production off the Chilean coast is demonstrated to be remarkably more regular over the 20th century, with variations of just 1% between the different do-decades.The authors with the Centre for Ocean Energy Research in Maynooth University are supported by Science Foundation Ireland under Grant No. 13/IA/1886. It is also supported by grant CGL2016-76561-R, MINECO/ERDF, UE. Additional funding was received from the University of Basque Country (UPV/EHU, GIU17/002)

MIDAS: A Benchmarking Multi-Criteria Method for the Identification of Defective Anemometers in Wind Farms

A novel multi-criteria methodology for the identification of defective anemometers is shown in this paper with a benchmarking approach: it is called MIDAS: multi-technique identification of defective anemometers. The identification of wrong wind data as provided by malfunctioning devices is very important, because the actual power curve of a wind turbine is conditioned by the quality of its anemometer measurements. Here, we present a novel method applied for the first time to anemometers’ data based on the kernel probability density function and the recent reanalysis ERA5. This estimation improves classical unidimensional methods such as the Kolmogorov–Smirnov test, and the use of the global ERA5’s wind data as the first benchmarking reference establishes a general method that can be used anywhere. Therefore, adopting ERA5 as the reference, this method is applied bi-dimensionally for the zonal and meridional components of wind, thus checking both components at the same time. This technique allows the identification of defective anemometers, as well as clear identification of the group of anemometers that works properly. After that, other verification techniques were used versus the faultless anemometers (Taylor diagrams, running correlation and RMSE RMSE , and principal component analysis), and coherent results were obtained for all statistical techniques with respect to the multidimensional method. The developed methodology combines the use of this set of techniques and was able to identify the defective anemometers in a wind farm with 10 anemometers located in Northern Europe in a terrain with forests and woodlands. Nevertheless, this methodology is general-purpose and not site-dependent, and in the future, its performance will be studied in other types of terrain and wind farmsThis work was financially supported by the Spanish Government through the MINECO project CGL2016-76561-R (MINECO/ERDF, UE), the University of the Basque Country through the Euskoiker PT10477 and GIU 17/002 contracts, and the project DIANEMOS of the Council of Gipuzkoa with Maxwind-Hispavista. ERA5 data were downloaded at no cost from the MARSserver of the ECMWF. Most of the calculations were carried out in the framework of

Molecular architecture of a multifunctional MCM complex

DNA replication is strictly regulated through a sequence of steps that involve many macromolecular protein complexes. One of them is the replicative helicase, which is required for initiation and elongation phases. A MCM helicase found as a prophage in the genome of Bacillus cereus is fused with a primase domain constituting an integrative arrangement of two essential activities for replication. We have isolated this helicase–primase complex (BcMCM) showing that it can bind DNA and displays not only helicase and primase but also DNA polymerase activity. Using single-particle electron microscopy and 3D reconstruction, we obtained structures of BcMCM using ATPγS or ADP in the absence and presence of DNA. The complex depicts the typical hexameric ring shape. The dissection of the unwinding mechanism using site-directed mutagenesis in the Walker A, Walker B, arginine finger and the helicase channels, suggests that the BcMCM complex unwinds DNA following the extrusion model similarly to the E1 helicase from papillomavirus

Effectiveness and safety of integrase strand transfer inhibitors in Spain: a prospective real-world study

IntroductionSecond-generation integrase strand transfer inhibitors (INSTIs) are preferred treatment options worldwide, and dolutegravir (DTG) is the treatment of choice in resource-limited settings. Nevertheless, in some resource-limited settings, these drugs are not always available. An analysis of the experience with the use of INSTIs in unselected adults living with HIV may be of help to make therapeutic decisions when second-generation INSTIs are not available. This study aimed to evaluate the real-life effectiveness and safety of dolutegravir (DTG), elvitegravir/cobicistat (EVG/c), and raltegravir (RAL) in a large Spanish cohort of HIV-1-infected patients.MethodsReal-world study of adults living with HIV who initiated integrase INSTIs DTG, EVG/c, and RAL-based regimens in three settings (ART-naïve patients, ART-switching, and ART-salvage patients). The primary endpoint was the median time to treatment discontinuation after INSTI-based regimen initiation. Proportion of patients experiencing virological failure (VF) (defined as two consecutive viral loads (VL) ≥200 copies/mL at 24 weeks or as a single determination of VL ≥1,000 copies/mL while receiving DTG, EVG/c or RAL, and at least 3 months after INSTI initiation) and time to VF were also evaluated.ResultsVirological effectiveness of EVG/c- and RAL-based regimens was similar to that of DTG when given as first-line and salvage therapy. Treatment switching for reasons other than virological failure was more frequent in subjects receiving EVG/c and, in particular, RAL. Naïve patients with CD4+ nadir <100 cells/μL were more likely to develop VF, particularly if they initiated RAL or EVG/c. In the ART switching population, initiation of RAL and EVG/c was associated with both VF and INSTI discontinuation. There were no differences in the time to VF and INSTI discontinuation between DTG, EVG/c and RAL. Immunological parameters improved in the three groups and for the three drugs assessed. Safety and tolerability were consistent with expected safety profiles.DiscussionWhereas second-generation INSTIs are preferred treatment options worldwide, and DTG is one of the treatment of choices in resource-limited settings, first-generation INSTIs may still provide high virological and immunological effectiveness when DTG is not available

Spatiotemporal Characteristics of the Largest HIV-1 CRF02_AG Outbreak in Spain: Evidence for Onward Transmissions

Background and Aim: The circulating recombinant form 02_AG (CRF02_AG) is the predominant clade among the human immunodeficiency virus type-1 (HIV-1) non-Bs with a prevalence of 5.97% (95% Confidence Interval-CI: 5.41–6.57%) across Spain. Our aim was to estimate the levels of regional clustering for CRF02_AG and the spatiotemporal characteristics of the largest CRF02_AG subepidemic in Spain.Methods: We studied 396 CRF02_AG sequences obtained from HIV-1 diagnosed patients during 2000–2014 from 10 autonomous communities of Spain. Phylogenetic analysis was performed on the 391 CRF02_AG sequences along with all globally sampled CRF02_AG sequences (N = 3,302) as references. Phylodynamic and phylogeographic analysis was performed to the largest CRF02_AG monophyletic cluster by a Bayesian method in BEAST v1.8.0 and by reconstructing ancestral states using the criterion of parsimony in Mesquite v3.4, respectively.Results: The HIV-1 CRF02_AG prevalence differed across Spanish autonomous communities we sampled from (p < 0.001). Phylogenetic analysis revealed that 52.7% of the CRF02_AG sequences formed 56 monophyletic clusters, with a range of 2–79 sequences. The CRF02_AG regional dispersal differed across Spain (p = 0.003), as suggested by monophyletic clustering. For the largest monophyletic cluster (subepidemic) (N = 79), 49.4% of the clustered sequences originated from Madrid, while most sequences (51.9%) had been obtained from men having sex with men (MSM). Molecular clock analysis suggested that the origin (tMRCA) of the CRF02_AG subepidemic was in 2002 (median estimate; 95% Highest Posterior Density-HPD interval: 1999–2004). Additionally, we found significant clustering within the CRF02_AG subepidemic according to the ethnic origin.Conclusion: CRF02_AG has been introduced as a result of multiple introductions in Spain, following regional dispersal in several cases. We showed that CRF02_AG transmissions were mostly due to regional dispersal in Spain. The hot-spot for the largest CRF02_AG regional subepidemic in Spain was in Madrid associated with MSM transmission risk group. The existence of subepidemics suggest that several spillovers occurred from Madrid to other areas. CRF02_AG sequences from Hispanics were clustered in a separate subclade suggesting no linkage between the local and Hispanic subepidemics

Nuevas funciones de los complejos MCM y Cohesina en el mantenimiento de la estabilidad genómica y la organización de la cromatina

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 29-10-2009The six minichromosome maintenance proteins (Mcm2‐7), which presumably constitute the core of the replicative DNA helicase, are present on chromatin in large excess relative to the numer of active replication forks. The function of this apparent surplus is not well understood, as most of them are displaced from the DNA during S‐phase, apparently without having played an active role in DNA replication. At least in yeast, Xenopus and Drosophila the concentration of MCM proteins can be reduced without affecting the DNA replication. This is known as the “MCM paradox”. In the first part of this work we tried to solve this classic controversy of eucharyotic cells. To evaluate the importance of MCM concentration in human cells, we have used RNA interference (RNAi) to modulate the expression of Mcm2‐7 genes and effectively reduce the concentration of Mcm2‐7 proteins on chromatin. We found conditions in which cells are capable of apparently normal replication with a very reduced concentration of Mcm2‐7 complexes. However, under these conditions of limited licensing, cells progressively accumulated DNA lesions and displayed chromosomal fragility. An analysis of origin density revealed that “excess” MCM proteins, although not necessarily active during an unperturbed S‐phase, might activate a reservoir of backup origins that are required to recover from DNA replication stress. Our data show that the chromatin‐bound “excess” Mcm2‐7 complexes are essential to maintain genomic integrity in human cells. Different lines of evidence show that Mcm2‐7 complex or its individual subunits could be involved in other processes apart from DNA replication. The systematic Knock‐Down of these proteins led us to identify an essential role for MCM proteins during the checkpoint activation. Our data indicate that this role would be limited to the replication checkpoint, where the Mcm2 and Mcm5 proteins appear to be essential to promote Chk1 activation upon diverse treatments that cause fork stalling. We show that after checkpoint induction these proteins interacted with the ATR allosteric activator TopBP1, which mails to relocate to affected replication forks in Mcm2 Knocked‐down cells. These data propose the participation of these two single proteins in the activation of the replication checkpoint by locating/estabilizing TopBP1 to stalled forks. Finally, we tried to identify new proteins associated with the MCM complex that could help to understand their different functions. This led us to identify Cohesin, a protein complex that mediates sister chromatid cohesion, as an MCM partner. To our surprise, MCM was not involved in cohesion establishment but Cohesin appeared to be essential for DNA replication. Cohesin is enriched at replication origins and its downregulation led to a decreased density of active origins, delaying S‐phase progression. Taking into account the ability of Cohesin to constrain the DNA topology and its presence in the nucleoskeleton, we demonstrate that Cohesin is an architectural element of the nucleus participating in the generation of chromatin loops. This function affects DNA replication, as some of the matrix‐bound regions are replication origins. This study contributes to our understanding of the roles of Cohesin in a variety of processes and adds new clues to the higher order chromatin organization in the nucleus

Cdc45-MCM-GINS, a new power player for DNA replication

Abstract The identity of the DNA helicase(s) involved in eukaryotic DNA replication is still a matter of debate, but the mini-chromosome maintenance (MCM) proteins are the chief candidate. Six conserved MCM proteins, Mcm2–7, are essential for the initiation and elongation stages of DNA replication, contain ATP binding pockets and can form a hexameric structure resembling that of known prokaryotic and viral helicases. However, biochemical proof of their presumed function has remained elusive. Several recent reports confirm that the MCM complex is part of the cellular machine responsible for the unwinding of DNA during S phase. In one of these reports, the helicase activity of Mcm2–7 is finally revealed, when they are purified in association with two partners: initiation factor Cdc45 and a four-subunit complex called GINS. The Cdc45-MCM-GINS complex could constitute the core of a larger macromolecular structure that has been termed the "replisome progression complex".</p

Excess MCM proteins protect human cells from replicative stress by licensing backup origins of replication

The six main minichromosome maintenance proteins (Mcm2–7), which presumably constitute the core of the replicative DNA helicase, are present in chromatin in large excess relative to the number of active replication forks. To evaluate the relevance of this apparent surplus of Mcm2–7 complexes in human cells, their levels were down-regulated by using RNA interference. Interestingly, cells continued to proliferate for several days after the acute (>90%) reduction of Mcm2–7 concentration. However, they became hypersensitive to DNA replication stress, accumulated DNA lesions, and eventually activated a checkpoint response that prevented mitotic division. When this checkpoint was abrogated by the addition of caffeine, cells quickly lost viability, and their karyotypes revealed striking chromosomal aberrations. Single-molecule analyses revealed that cells with a reduced concentration of Mcm2–7 complexes display normal fork progression but have lost the potential to activate “dormant” origins that serve a backup function during DNA replication. Our data show that the chromatin-bound “excess” Mcm2–7 complexes play an important role in maintaining genomic integrity under conditions of replicative stress