Enthesitis indices identify different patients with this characteristic in axial and peripheral spondyloarthritis and also in psoriatic arthritis: ASAS-PerSpA data.

BACKGROUND: In axial spondyloarthritis (axSpA), peripheral SpA (pSpA) and psoriatic arthritis (PsA), enthesitis is a hallmark clinical feature that can be assessed by the SPARCC index, LEI, MASES and MEI. These indices evaluate different locations, which may identify different numbers of patients with enthesitis among SpA subtypes. Thus, the aim of this study was to evaluate whether the proportion of patients with at least one enthesitis across these three most prevalent SpA subtypes differs according to the index used and to evaluate the level of agreement among indices in detecting patients with enthesitis. METHODS: A total of 4185 patients (2719 axSpA, 433 pSpA and 1033 PsA) from the international and cross-sectional ASAS-PerSpA study were included. The proportion of patients with enthesitis identified by the indices was evaluated across the three diseases. Pairwise agreement between indices was computed using Cohen's kappa. RESULTS: The prevalence rates of patients with at least one enthesitis according to the MEI, MASES, SPARCC index and LEI were 17.2%, 13.5%, 10.7%, and 8.3%, respectively. In axSpA, the indices that identified the most patients with enthesitis were the MEI and MASES (98.7% and 82.4%, respectively); in pSpA and PsA, the indices that identified the most patients with enthesitis were the MEI and SPARCC index (MEI: 100% and SPARCC: 84.6%; MEI: 97.3% and SPARCC: 77%, respectively). In the total population, the MASES vs. MEI showed the strongest agreement (absolute agreement 96.3%; kappa: 0.86); similar results were obtained in axSpA patients (97.3%; 0.90). In pSpA and PsA patients, the SPARCC vs. MEI (97.2%; 0.90 and 95.4%; 0.83, respectively) showed the strongest agreement. CONCLUSIONS: These results suggest that the prevalence of patients with enthesitis across SpA subtypes differs depending on the disease and the index used. The MEI and MASES appeared best for assessing enthesis in SpA and axSpA, while the MEI and SPARCC index appeared best for assessing enthesitis in pSpA and PsA.

Kinetic Monte Carlo simulations for heterogeneous catalysis: Fundamentals, current status, and challenges.

Kinetic Monte Carlo (KMC) simulations in combination with first-principles (1p)-based calculations are rapidly becoming the gold-standard computational framework for bridging the gap between the wide range of length scales and time scales over which heterogeneous catalysis unfolds. 1p-KMC simulations provide accurate insights into reactions over surfaces, a vital step toward the rational design of novel catalysts. In this Perspective, we briefly outline basic principles, computational challenges, successful applications, as well as future directions and opportunities of this promising and ever more popular kinetic modeling approach.

Cognitive stimulation has potential for brain activation in individuals with Rett syndrome.

BACKGROUND: Knowledge regarding neuropsychological training in Rett syndrome (RS) is scarce. The aim of this study was to assess the outcome and the duration of the effect of cognitive stimulation on topographic electroencephalography (EEG) data in RS. METHODS: Twenty female children diagnosed with RS were included in the analysis. Girls with RS conducted a cognitive task using an eye-tracker designed to evaluate access and choice skills. EEG data were acquired during the experimental procedure including two 10-min baseline stages before and after the task. Topographical changes of several EEG spectral markers including absolute and relative powers, Brain Symmetry Index and entropy were assessed. RESULTS: Topographic significance probability maps suggested statistical decreases on delta activity and increases on beta rhythm associated with the cognitive task. Entropy increased during and after the task, likely related to more complex brain activity. A significant positive interaction was obtained between Brain Symmetry Index and age showing that the improvement of interhemispheric symmetry was higher in younger girls (5-10 years). CONCLUSIONS: According to our findings, significant alterations of brain rhythms were observed during and after cognitive stimulation, suggesting that cognitive stimulation may have effects on brain activity beyond the stimulation period. Finally, our promising results also showed an increase brain symmetry that was especially relevant for the younger group. This could suggest an interaction of the eye-tracking cognitive task; however, further studies in this field are needed to assess the relation between brain asymmetries and age.

Fisiopatología de la osteoporosis en las enfermedades articulares inflamatorias crónicas / Pathophysiology of osteoporosis in chronic inflammatory joint diseases

El sistema inmune y el hueso comparten con frecuencia los mismos nichos y espacios anatómicos, existiendo una estrecha relación funcional entre ambos. Esto hace que haya una interacción constante entre ellos, con un flujo bidireccional de información entre las células inmunes y las del tejido óseo (osteoclastos, osteoblastos y osteocitos), muchas veces desconocida, en la que intervienen múltiples mediadores inflamatorios y diversos factores de crecimiento y diferenciación celular. Ello conduce a una interacción muy estrecha entre inflamación y pérdida ósea. De hecho, la osteoporosis (OP) es una de las complicaciones sistémicas más frecuentes en las enfermedades inflamatorias crónicas (EIC). La prevalencia de OP en las EIC es variable y depende de cada escenario patológico. La artritis reumatoide (AR) es una de las enfermedades paradigmáticas de inflamación crónica, donde la presencia de OP es frecuente, apareciendo incluso antes de que aparezcan los primeros síntomas de la enfermedad. La patogenia de la OP asociada a la AR es compleja e incluye la colaboración de múltiples citoquinas proinflamatorias que favorecen la osteoclastogénesis e inhiben la formación ósea. Entre todas destacan el factor de necrosis tumoral alfa (conocido en inglés como TNF-α) y diversas interleuquinas (IL) como IL-1, IL-6 e IL-17. De todas, IL-6 tiene un papel jerárquico relevante. En esta revisión se repasa el papel de las citoquinas proinflamatorias en la destrucción ósea y articular en diferentes EIC, con especial énfasis en la AR, planteándose las bases de posibles vías que abran nuevos horizontes terapéuticos en el marco de las EIC. (AU)

The immune system and the bone often share the same anatomical niches and spaces, as there is a close functional relationship between both of them. As a consequence, there is a constant interaction between them and a bidirectional flow of information between the immune cells and those of the bone tissue (osteoclasts, osteoblasts and osteocytes) often unknown, in which multiple inflammatory mediators and various growth and cell differentiation factors are involved. This leads to a very close interaction between inflammation and bone loss. In fact, osteoporosis (OP) is one of the most frequent systemic complications in chronic inflammatory diseases (CIDs). The prevalence of OP in CIDs depends on each pathological scenario. Rheumatoid arthritis (RA) is a paradigmatic disease which causes chronic inflammation, where the presence of OP is frequent and shows even prior to the appearance of the first symptoms of the RA. The pathogenesis of RA-associated OP is complex and includes the cooperation of multiple pro-inflammatory cytokines that promote osteoclastogenesis and inhibit bone formation. Tumor necrosis factor alpha (TNF-α) and different interleukins (IL), such as IL-1, IL-6 and IL-17, stand out among all, IL-6 having a relevant hierarchical role. In this study, we review the role of pro-inflammatory cytokines in bone and joint destruction in different CIDs, giving special emphasis to RA, as we set out the bases of possible pathways that open new therapeutic horizons in the their framework. (AU)

Significant differences in access to tests and treatments for multiple myeloma between public and private systems in Latin America. Results of a Latin American survey. GELAMM (Grupo de Estudio Latino Americano de Mieloma Múltiple).

The incidence of multiple myeloma (MM) has increased in the last 20 years, particularly in middle and low-middle income countries. Access to diagnostic and prognostic tests and the availability of effective care is highly variable globally. Latin America represents 10% of the world population, distributed in countries of varied size, population, and socio-economic development. In the last decade, great improvements have been made in the diagnosis and treatment of MM. Applying these advances in real life is a challenge in our region. Local data regarding MM standards of care and outcomes are limited. A survey was carried out among hematologists from 15 Latin American countries to describe access to MM diagnostic and prognostic tests and the availability of effective care options. This study provides real-world data for MM in our region, highlighting striking differences between public and private access to essential analyses and therapeutic options.

Trypanosoma cruzi cleaves galectin-3 N-terminal domain to suppress its innate microbicidal activity.

Galectin-3 is the best-characterized member of galectins, an evolutionary conserved family of galactoside-binding proteins that play central roles in infection and immunity, regulating inflammation, cell migration and cell apoptosis. Differentially expressed by cells and tissues with immune privilege, they bind not only to host ligands, but also to glycans expressed by pathogens. In this regard, we have previously shown that human galectin-3 recognizes several genetic lineages of the protozoan parasite Trypanosoma cruzi, the causal agent of Chagas' disease or American trypanosomiasis. Herein we describe a molecular mechanism developed by T. cruzi to proteolytically process galectin-3 that generates a truncated form of the protein lacking its N-terminal domain - required for protein oligomerization - but still conserves a functional carbohydrate recognition domain (CRD). Such processing relies on specific T. cruzi proteases, including Zn-metalloproteases and collagenases, and ultimately conveys profound changes in galectin-3-dependent effects, as chemical inhibition of parasite proteases allows galectin-3 to induce parasite death in vitro. Thus, T. cruzi might have established distinct mechanisms to counteract galectin-3-mediated immunity and microbicide properties. Interestingly, non-pathogenic T. rangeli lacked the ability to cleave galectin-3, suggesting that during evolution two genetically similar organisms have developed different molecular mechanisms that, in the case of T. cruzi, favoured its pathogenicity, highlighting the importance of T. cruzi proteases to avoid immune mechanisms triggered by galectin-3 upon infection. This study provides the first evidence of a novel strategy developed by T. cruzi to abrogate signalling mechanisms associated with galectin-3-dependent innate immunity.

Perfil clínico y sociodemográfico de la epilepsia en adultos de un centro de referencia de Colombia / Clinical and sociodemographic profile of epilepsy in adults from a reference centre in Colombia

Objetivos: Describir las características clínicas y sociodemográficas de pacientes con epilepsia de un centro de referencia de Colombia. Métodos: Estudio de corte transversal. Se incluyó a los pacientes con diagnóstico de epilepsia que acudieron al centro de epilepsia Neurocentro en el período comprendido entre los años 2013 y 2016. La información se obtuvo de las historias clínicas. Resultados: Se estudió a 354 pacientes con diagnóstico de epilepsia. La mediana de edad fue de 37 años y el 52% eran hombres. El 57% presentó crisis de tipo focales, el 38% de tipo generalizada y 6% sin clasificar. La etiología más prevalente fue la criptogénica (21%) seguida de la traumática (14%). La mediana de tiempo de evolución de la epilepsia y de inicio de las crisis fue de 23 años y 11 años, respectivamente. La comorbilidad psiquiátrica se encontró en el 18% de los pacientes. El 40% presentó algún grado de deterioro cognitivo y la misma proporción refirió efectos adversos a los antiepilépticos en algún momento durante su tratamiento. El manejo farmacológico con antiepilépticos en monoterapia se presentó en el 36%. La farmacorresistencia fue hallada en 37% de los estudiados. Se realizó intervención quirúrgica en el 14% del total de pacientes. Conclusiones: Observamos que la comorbilidad psiquiátrica, el deterioro cognitivo, las reacciones adversas a los antiepilépticos y la farmacorresistencia son frecuentes entre los pacientes epilépticos en Colombia. Esperamos que este estudio sirva como soporte para lograr una legislación en salud más integral que mejore la calidad de vida de estos pacientes teniendo en cuenta todas las variables que influyen en la enfermedad

Objectives: To describe the sociodemographic and clinical characteristics of a cohort of patients with epilepsy from a reference centre in Colombia. Methods: Cross-sectional study including patients diagnosed with epilepsy who attended our epilepsy centre (Neurocentro) between 2013 and 2016. Data were gathered from patients' medical histories. Results: We gathered data from a total of 354 patients diagnosed with epilepsy. Median age was 37 years; 52% were men. Seizures were focal in 57% of the patients and generalised in 38%; seizure type was not determined in 6% of the sample. The most frequent aetiology was cryptogenic (21%), followed by traumatic (14%). Median time of disease progression and age at onset were 23 and 11 years, respectively. Psychiatric comorbidities were found in 18% of the patients and 40% had some degree of cognitive impairment. Around 40% of our sample reported adverse reactions to antiepileptic drugs at some point during treatment. Antiepileptic drugs were administered in monotherapy in 36% of the patients. Around 37% had drug-resistant epilepsy and 14% underwent surgery. Conclusions: Psychiatric comorbidities, cognitive impairment, adverse drug reactions, and drug-resistant epilepsy are common among epileptic patients in Colombia. Knowledge of the factors with an impact on epilepsy may lay the foundations for improving management of these patients on the administrative level and improving quality of life

The most recurrent monogenic disorders that overlap with the phenotype of Rett syndrome.

Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that is caused by mutations in the MECP2 gene; however, defects in other genes (CDKL5 and FOXG1) can lead to presentations that resemble classic RTT, although they are not completely identical. Here, we attempted to identify other monogenic disorders that share features of RTT. A total of 437 patients with a clinical diagnosis of RTT-like were studied; in 242 patients, a custom panel with 17 genes related to an RTT-like phenotype was run via a HaloPlex-Target-Enrichment-System. In the remaining 195 patients, a commercial TruSight-One-Sequencing-Panel was analysed. A total of 40 patients with clinical features of RTT had variants which affect gene function in six genes associated with other monogenic disorders. Twelve patients had variants in STXBP1, nine in TCF4, six in SCN2A, five in KCNQ2, four in MEF2C and four in SYNGAP1. Genetic studies using next generation sequencing (NGS) allowed us to study a larger number of genes associated with RTT-like simultaneously, providing a genetic diagnosis for a wider group of patients. These new findings provide the clinician with more information and clues that could help in the prevention of future symptoms or in pharmacologic therapy.

Detection of White Root Rot in Avocado Trees by Remote Sensing.

White root rot, caused by the soilborne fungus Rosellinia necatrix, is an important constraint to production for a wide range of woody crop plants such as avocado trees. The current methods of detection of white root rot are based on microbial and molecular techniques, and their application at orchard scale is limited. In this study, physiological parameters provided by imaging techniques were analyzed by machine learning methods. Normalized difference vegetation index (NDVI) and normalized canopy temperature (canopy temperature - air temperature) were tested as predictors of disease by several algorithms. Among them, logistic regression analysis (LRA) trained on NDVI data showed the highest sensitivity and lowest rate of false negatives. This algorithm based on NDVI could be a quick and feasible method to detect trees potentially affected by white root rot in avocado orchards.

Clinical and sociodemographic profile of epilepsy in adults from a reference centre in Colombia. / Perfil clínico y sociodemográfico de la epilepsia en adultos de un centro de referencia de Colombia.

OBJECTIVES: To describe the sociodemographic and clinical characteristics of a cohort of patients with epilepsy from a reference centre in Colombia. METHODS: Cross-sectional study including patients diagnosed with epilepsy who attended our epilepsy centre (Neurocentro) between 2013 and 2016. Data were gathered from patients' medical histories. RESULTS: We gathered data from a total of 354 patients diagnosed with epilepsy. Median age was 37 years; 52% were men. Seizures were focal in 57% of the patients and generalised in 38%; seizure type was not determined in 6% of the sample. The most frequent aetiology was cryptogenic (21%), followed by traumatic (14%). Median time of disease progression and age at onset were 23 and 11 years, respectively. Psychiatric comorbidities were found in 18% of the patients and 40% had some degree of cognitive impairment. Around 40% of our sample reported adverse reactions to antiepileptic drugs at some point during treatment. Antiepileptic drugs were administered in monotherapy in 36% of the patients. Around 37% had drug-resistant epilepsy and 14% underwent surgery. CONCLUSIONS: Psychiatric comorbidities, cognitive impairment, adverse drug reactions, and drug-resistant epilepsy are common among epileptic patients in Colombia. Knowledge of the factors with an impact on epilepsy may lay the foundations for improving management of these patients on the administrative level and improving quality of life.

Safety and dose modification for patients receiving niraparib.

Background: Niraparib is a poly(ADP-ribose) polymerase inhibitor approved in the USA and Europe for maintenance treatment of adult patients with recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer who are in complete or partial response to platinum-based chemotherapy. In the pivotal ENGOT-OV16/NOVA trial, the dose reduction rate due to treatment-emergent adverse event (TEAE) was 68.9%, and the discontinuation rate due to TEAE was 14.7%, including 3.3% due to thrombocytopenia. A retrospective analysis was carried out to identify clinical parameters that predict dose reductions. Patients and methods: All analyses were carried out on the safety population, comprising all patients who received at least one dose of study drug. Patients were analyzed according to the study drug consumed (i.e., as treated). A predictive modeling method (decision trees) was used to identify important variables for predicting the likelihood of developing grade ≥3 thrombocytopenia within 30 days after the first dose of niraparib and determine cut-off points for chosen variables. Results: Following dose modification, 200 mg was the most commonly administered dose in the ENGOT-OV16/NOVA trial. Baseline platelet count and baseline body weight were identified as risk factors for increased incidence of grade ≥3 thrombocytopenia. Patients with a baseline body weight <77 kg or a baseline platelet count <150 000/µl in effect received an average daily dose ∼200 mg (median = 207 mg) due to dose interruption and reduction. Progression-free survival in patients who were dose reduced to either 200 or 100 mg was consistent with that of patients who remained at the 300 mg starting dose. Conclusions: The analysis presented suggests that patients with baseline body weight of <77 kg or baseline platelets of <150 000/µl may benefit from a starting dose of 200 mg/day. ClinicalTrials.gov ID: NCT01847274.

Predicting soil water content at - 33 kPa by pedotransfer functions in stoniness 1 soils in northeast Venezuela.

Soil water content is a key property in the study of water available for plants, infiltration, drainage, hydraulic conductivity, irrigation, plant water stress and solute movement. However, its measurement consumes time and, in the case of stony soils, the presence of stones difficult to determinate the water content. An alternative is the use of pedotransfer functions (PTFs), as models to predict these properties from readily available data. The present work shows a comparison of different widely used PTFs to estimate water content at-33 kPa (WR-33kPa) in high stoniness soils. The work was carried out in the Caramacate River, an area of high interest because the frequent landslides worsen the quality of drinking water. The performance of all evaluated PTFs was compared with a PTF generated for the study area. Results showed that the Urach's PTF presented the best performance in relation to the others and could be used to estimate WR-33kPa in soils of Caramacate River basin. The calculated PTFs had a R2 of 0.65. This was slightly higher than the R2 of the Urach's PTF. The inclusion of the rock fragment volume could have the better results. The weak performance of the other PTFs could be related to the fact that the mountain soils of the basin are rich in 2:1 clay and high stoniness, which were not used as independent variables for PTFs to estimate the WR-33kPa.

Gene Silencing of Argonaute5 Negatively Affects the Establishment of the Legume-Rhizobia Symbiosis.

The establishment of the symbiosis between legumes and nitrogen-fixing rhizobia is finely regulated at the transcriptional, posttranscriptional and posttranslational levels. Argonaute5 (AGO5), a protein involved in RNA silencing, can bind both viral RNAs and microRNAs to control plant-microbe interactions and plant physiology. For instance, AGO5 regulates the systemic resistance of Arabidopsis against Potato Virus X as well as the pigmentation of soybean (Glycine max) seeds. Here, we show that AGO5 is also playing a central role in legume nodulation based on its preferential expression in common bean (Phaseolus vulgaris) and soybean roots and nodules. We also report that the expression of AGO5 is induced after 1 h of inoculation with rhizobia. Down-regulation of AGO5 gene in P. vulgaris and G. max causes diminished root hair curling, reduces nodule formation and interferes with the induction of three critical symbiotic genes: Nuclear Factor Y-B (NF-YB), Nodule Inception (NIN) and Flotillin2 (FLOT2). Our findings provide evidence that the common bean and soybean AGO5 genes play an essential role in the establishment of the symbiosis with rhizobia.

Modelling the collective response of heterogeneous cell populations to stationary gradients and chemical signal relay.

The directed motion of cell aggregates toward a chemical source occurs in many relevant biological processes. Understanding the mechanisms that control this complex behavior is of great relevance for our understanding of developmental biological processes and many diseases. In this paper, we consider a self-propelled particle model for the movement of heterogeneous subpopulations of chemically interacting cells towards an imposed stable chemical gradient. Our simulations show explicitly how self-organisation of cell populations (which could lead to engulfment or complete cell segregation) can arise from the heterogeneity of chemotactic responses alone. This new result complements current theoretical and experimental studies that emphasise the role of differential cell-cell adhesion on self-organisation and spatial structure of cellular aggregates. We also investigate how the speed of individual cell aggregations increases with the chemotactic sensitivity of the cells, and decreases with the number of cells inside the aggregates.

Beyond mean-field approximations for accurate and computationally efficient models of on-lattice chemical kinetics.

Modeling the kinetics of surface catalyzed reactions is essential for the design of reactors and chemical processes. The majority of microkinetic models employ mean-field approximations, which lead to an approximate description of catalytic kinetics by assuming spatially uncorrelated adsorbates. On the other hand, kinetic Monte Carlo (KMC) methods provide a discrete-space continuous-time stochastic formulation that enables an accurate treatment of spatial correlations in the adlayer, but at a significant computation cost. In this work, we use the so-called cluster mean-field approach to develop higher order approximations that systematically increase the accuracy of kinetic models by treating spatial correlations at a progressively higher level of detail. We further demonstrate our approach on a reduced model for NO oxidation incorporating first nearest-neighbor lateral interactions and construct a sequence of approximations of increasingly higher accuracy, which we compare with KMC and mean-field. The latter is found to perform rather poorly, overestimating the turnover frequency by several orders of magnitude for this system. On the other hand, our approximations, while more computationally intense than the traditional mean-field treatment, still achieve tremendous computational savings compared to KMC simulations, thereby opening the way for employing them in multiscale modeling frameworks.

Landslides susceptibility change over time according to terrain conditions in a mountain area of the tropic region.

Susceptibility to landslides in mountain areas results from the interaction of various factors related to relief formation and soil development. The assessment of landslide susceptibility has generally taken into account individual events, or it has been aimed at establishing relationships between landslide-inventory maps and maps of environmental factors, without considering that such relationships can change in space and time. In this work, temporal and space changes in landslides were analysed in six different combinations of date and geomorphological conditions, including two different geological units, in a mountainous area in the north-centre of Venezuela, in northern South America. Landslide inventories from different years were compared with a number of environmental factors by means of logistic regression analysis. The resulting equations predicted landslide susceptibility from a range of geomorphometric parameters and a vegetation index, with diverse accuracy, in the study area. The variation of the obtained models and their prediction accuracy between geological units and dates suggests that the complexity of the landslide processes and their explanatory factors changed over space and time in the studied area. This calls into question the use of a single model to evaluate landslide susceptibility over large regions.

Clinical Evolution After Enzyme Replacement Therapy in Twins with the Severe Form of Maroteaux-Lamy Syndrome.

Mucopolysaccharidosis type VI (MPS VI) is a progressive, autosomal, recessive lysosomal disorder. This disorder, due to a deficiency in N-acetylgalactosamine-4-sulfatase (ASB), results in an accumulation of glycosaminoglycan (GAG), causing multiple organ failures. In this study, monochorionic biamniotic twins with the severe form of MPS VI underwent enzyme replacement therapy (ERT) with weekly infusions of recombinant human ASB (galsulfase) at 1 mg/kg. After 9 years of ERT, a comprehensive clinical examination was performed. Several types of biochemical, immunological, and genetic investigations were also conducted. Both twins showed the typical symptoms and signs of MPS VI at baseline, including short stature, progressive dysmorphic facial features, and dysostosis multiplex. Twin 2 presented stronger multisystemic involvement, with marked musculoskeletal, neurological, and odontological components. She also developed an ischemic spinal cord lesion after surgery, which is the first case described in the literature in Maroteaux-Lamy syndrome. However, the extent of disease was found to be equally stabilized in the two sisters, concretely the cardiac and respiratory functions and body length. The early diagnosis and treatment of MPS VI are critical for an optimal clinical outcome, and further evidence for the new treatment strategies is needed.

Ongoing expansion of the worldwide invader Didemnum vexillum (Ascidiacea) in the Mediterranean Sea: high plasticity of its biological cycle promotes establishment in warm waters.

Non-indigenous ascidians are of particular concern to aquaculture industry and, paradoxically, the activities associated with it represent an important way to translocate these species worldwide. In 2012 a non-indigenous ascidian was found covering the oyster crops in the Ebro Delta (Western Mediterranean). We have identified the ascidian genetically and morphologically as Didemnum vexillum Kott, 2002. This finding indicates that the species is currently expanding its distribution in the Mediterranean Sea, as it has recently been found in the eastern basin (Venice, Adriatic Sea). Introduced populations of D. vexillum are found in temperate and cold waters worldwide, and a successful establishment in the Mediterranean implies a remarkable capacity of adaptability to warm, subtropical conditions. We assessed the life cycle (growth and reproduction) of the ascidian at the studied site. The species has a marked seasonal cycle, with regression in the warmest months and reappearance during winter. In spring D. vexillum reaches its maximum abundance, followed by a peak in reproduction just before regression. This cycle is reversed with respect to the one observed in colder waters, highlighting a plastic biological cycle of this invader and an hitherto unknown ability to establish itself in warm waters. We also analysed the genetic structure of the population of the Ebro Delta and the one established in the Lagoon of Venice using COI sequence data. The low genetic diversity in our samples (three haplotypes) was consistent with what is observed in the introduced populations worldwide. It is likely that the ascidian was introduced with oyster stock from bivalve cultures in the Atlantic French coasts, where the same three haplotypes have been reported. The high boating activity in the Ebro Delta makes further human-mediated transport of the species highly likely, and nearby fishing grounds can be severely affected if invaded. It is urgent to implement measures to prevent the continuous expansion of this ascidian pest in the Mediterranean.