Population biology of the sea star Anasterias minuta (Forcipulatida: Asteriidae) threatened by anthropogenic activities in rocky intertidal shores of San Matías Gulf, Patagonia, Argentina

In Patagonian coastal areas, intertidal benthic communities are exposed to extreme physical conditions. The interaction between harsh environment and anthropogenic pressure can generate changes in population biology of marine invertebrates, like density and reproduction. The oral brooding sea star Anasterias minuta is a key organism in food chains of Atlantic Patagonian rocky intertidals, hence changes on its population structure can negatively affect shore communities. We studied the population biology of A. minuta and assess the effect of environmental parameters and anthropogenic activities on its population on rocky intertidal shores of San Matías Gulf, Patagonia, Argentina. Seasonal sea surface temperature, pH, salinity, water velocity, desiccation rate, boulders density, and anthropogenic influence (tourists and octopus fishermen) were recorded. In sites with less tourist influence and high refuge, an increase in density was recorded, especially during the summer. Brooding individuals were found in fall and winter, while feeding individuals were observed in all seasons (12 different prey, mainly the molluscs Tegula patagonica and Perumytilus purpuratus). Environmental variables such as boulders density and water velocity were the most important predictor of variation in population structure. Tourism and pH were the most important variables negatively correlated with density.Fil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Bagur Creta, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Grupo de Investigación y Educación en Temas Ambientales; ArgentinaFil: Palomo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Grupo de Investigación y Educación en Temas Ambientales; ArgentinaFil: Bigatti, Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; Argentina. Universidad Nacional de la Patagonia; Argentin

Does rock type account for variation in mussel attachment strength? A test with Brachidontes rodriguezii in the southwestern Atlantic

Mussel attachment strength varies in space and time, frequently in association with variations in wave exposure. Yet, it remains uninvestigated whether different rock types can contribute to variation in mussel attachment. Here we compared the attachment strength of the mussel Brachidontes rodriguezii between soft and hard intertidal rock substrates that are typical of coastal Buenos Aires Province, Argentina: Pampean loess cemented by calcium carbonate and orthoquartzite, respectively. Overall comparisons of mussel attachment across natural platforms of either rock type (10 loess sites and 4 orthoquartzite sites) indicated stronger mussel attachment to orthoquartzite. However, mussel attachment strength did not differ when compared across natural loess platforms and introduced orthoquartzite blocks (i.e., groins and revetments) occurring within the same site. Mussels attaching to loess showed more byssal threads than those attaching to orthoquartzite at the same site. These findings suggest, first, that rock type does not influence mussel attachment strength in our study system, secondly, that overall differences in mussel attachment strength with rock type across natural platforms in our study range are due to confounding influences of co-varying factors (e.g., wave exposure) and, finally, that mussels can increase byssus production to counteract potential substrate failure when attaching to soft, friable rock. The latter likely explains the ability of mussels to maintain relatively stable cover across rocks of contrasting hardness.Fil: Gutierrez, Jorge Luis Ceferino. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Bagur, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Palomo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Abundance data for invertebrate assemblages from intertidal mussel beds along the Atlantic Canadian coast

This data set describes the abundance of invertebrate taxa found in intertidal mussel beds along the Atlantic Canadian coast. The data resulted from a regional-scale study that investigated the effects of wave exposure on the richness and composition of invertebrate assemblages from intertidal mussel beds. Abundance data are provided for taxa representing the Annelida, Arthropoda, Bryozoa, Chordata, Cnidaria, Echinodermata, Mollusca, Nematoda, Nemertea, and Platyhelminthes. The data characterize mussel beds from wave-sheltered and wave-exposed locations spanning 315 km of coast. Univariate and multivariate analyses revealed that the compositional structure of these invertebrate assemblages differed markedly depending on wave exposure. Overall, this data set exhibits important properties that could make it useful to test broader ecological theory. Such properties include its taxonomic diversity, the possession of data for basal, intermediate, and top trophic levels, and the coverage of two extremes of environmental stress. Thus, areas of ecology that could experience advances using this data set are those concerning environmental stress models of community organization, abundance–occupancy relationships, species co-occurrence, species abundance distributions, dominance and rarity, spatial scales of population and community variation, and distribution of functional and phylogenetic diversity.Fil: Scrosati, Ricardo Augusto. Saint Francis Xavier University; CanadáFil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Donnarumma, Luigia. Università degli Studi di Napoli Parthenope. Dipartimento di Scienze e Tecnologie; Itali

Echinoderms diversity in the Southwestern Atlantic

Studies of biodiversity of echinoderms from South America have increased in recent years. Here we summarize sampling done on three expeditions along the Argentinean coast (35º - 55º S) and near the Antarctic Peninsula. The first campaign, Mejillón II (M-II; 2009), was carried out between 35º - 39º S and covered a depth range between 10 to 140 m. The second was part of the Summer Antarctic Campaign 2011 (CAV-III; 2011) that took place around the Antarctic Peninsula, South Shetland and South Orkney Islands (depth range between 67 to 754 m). The last cruise was the final stretch of the Summer Antarctic Campaign 2011 (CAV-IV; 2011), from 39º - 55º S and between 30 - 140 m depth. As result, 74 stations have been studied, of which 68 had at least one echinoderm specimen. From the total number of stations, the occurrence percentages for each class were Asteroidea (68 %), Echinoidea (64 %), Ophiuroidea (55 %), Holothuroidea (51 %) and Crinoidea (20 %). In the M-II campaign, echinoderms were presented in 94 % of the sampled stations, with Echinoidea most frequent (74 %). In the CAV-III campaign echinoderms were presented in all the stations; Ophiuroidea were found in all stations. The lowest occurrence of echinoderms was found in the CAV-IV campaign (82 %), where Asteroidea was present in the 73 % of the samples, and crinoids were absent.Fil: Martinez, Mariano Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Berecoechea, Juan José. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Brogger, Martin Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Penchaszadeh, Pablo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Competencia entre mitílidos en el intermareal rocoso de La Lobería, Río Negro, Argentina

Competitive interactions between individuals from a single or different species can regulate population densities and individual growth. Two mussel species, Brachidontes rodriguezii and Perumytilus purpuratus coexist in the rocky intertidal zone of La Lobería, Río Negro Province, Argentina. The aim of this study was to analyse the effect of intra- and interspecific competition growth and mortality of both bivalve species. An experiment was conducted to evaluate the intra- and interspecific competition using asbestos cement plates of 10 x 10 cm varying mussel densities. The width of P. purpuratus showed a significant increase in presence of B. rodriguezii. There also was a non-significant trend toward decreasing B. rodriguezii size with increasing density of conspecifics and when coexisting with P. purpuratus. Mortality of B. rodriguezii and P. purpuratus did not differ significantly among treatments. Limited supply of P. purpuratus larvae or local tidal conditions that differentially affect each species could be leading to weak competition between both mussel species, thus allowing their coexistence.Las interacciones competitivas entre individuos de una misma o distintas especies pueden regular las densidades poblacionales y el crecimiento individual. Dos especies de mitílidos, Brachidontes rodriguezii y Perumytilus purpuratus, coexisten en el intermareal rocoso de La Lobería, provincia de Río Negro, Argentina. El objetivo de este trabajo fue analizar el efecto de la competencia intra- e interespecífica sobre el crecimiento y la mortalidad de ambas especies de bivalvos. Se realizó un experimento para evaluar la competencia intra- e interespecífica utilizando placas de fibrocemento de 10 x 10 cm variando las densidades de mitílidos. El ancho de P. purpuratus mostró un aumento significativo ante la presencia de B. rodriguezii. Se observó también una tendencia no significativa hacia la disminución de tallas de B. rodriguezii al aumentar la densidad de coespecíficos y al coexistir con P. purpuratus. La mortalidad de B. rodriguezii y P. purpuratus no mostró diferencias significativas entre tratamientos. Un limitado arribo de larvas de P. purpuratus o condiciones locales del intermareal que benefician diferencialmente a las especies podrían llevar a que los efectos de competencia entre estas sean débiles, haciendo posible la coexistencia.Fil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Bagur Creta, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Soria, Sabrina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Gutierrez, Jorge Luis Ceferino. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales; Argentina. Estación Biológica Las Brusquitas. Grupo de Investigación y Educación en Temas Ambientales; ArgentinaFil: Palomo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Estación Biológica Las Brusquitas. Grupo de Investigación y Educación en Temas Ambientales; Argentin

Dátiles de mar: Mejillones que perforan las rocas costeras

A diferencia de sus famosos homónimos producidos por palmeras, los dátiles de mar son animales. Se trata de unos moluscos bivalvos poco conocidos que miden unos pocos centímetros y se distinguen por su capacidad de horadar cavidades en rocas calizas de la zona intermareal. Viven en ellas protegidos de predadores, del embate de olas y de la desecación que los amenaza cuando se retiran las aguas. No perforan las rocas en forma mecánica sino química, pues secretan un ácido que disuelve el carbonato de calcio. Su acción hace que a menudo se los considere perjudiciales, aunque también contribuyen al incremento de la biodiversidad del ambiente costero. Una especie de ellos, llamada Lithophaga patagonica, es muy abundante en las costas argentinas.Fil: Bagur Creta, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Palomo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; ArgentinaFil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; ArgentinaFil: Gutierrez, Jorge Luis Ceferino. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Wave action limits crowding in an intertidal mussel

Intraspecific competition for space is generally invoked as the chief process limiting crowding in sessile or highly sedentary marine invertebrates. However, the mechanisms by which high conspecific density induces individual removal or mortality, in turn restraining crowding in these organisms, generally remain uninvestigated. Here we illustrate that mussel crowding in a southwestern Atlantic rocky intertidal shore is limited by a combination of wave action and space limitation. Brachidontes rodriguezii mussel beds at this site occur primarily as a single layer of individuals because wave forces remove multilayered mussel hummocks quickly after they develop. Mussels in hummocks show lower attachment strength than those in the single-layered matrix. Accordingly, wave conditions associated with the passage of cold fronts (i.e. transition zones from warm air to cold air accompanied by moderate to strong winds and wave action, with 7 d average recurrence times based on historical weather data) cause detectable mussel dislodgment in a high proportion of hummocks but have virtually no impact on single-layered areas. Since wave action is the proximate cause of mussel dislodgment, upper limits to crowding in this species would not be fixed to a particular level of space occupation (i.e. as predictable from inter-individual interference alone) but would be variable in space and time depending on wave exposure. This example suggests a mechanism of population control where the impact of a physical factor on population size is larger at higher population density and supports early hypotheses about the occurrence of density-dependent population control by physical factors when the availability of safe sites is limiting.Fil: Gutierrez, Jorge Luis Ceferino. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Cary Institute of Ecosystem Studies; Estados UnidosFil: Palomo, Maria Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Bagur Creta, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Arribas, Lorena Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Soria, Sabrina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Shared genetic background between children and adults with attention deficit/hyperactivity disorder

Attention deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder characterized by age-inappropriate symptoms of inattention, impulsivity, and hyperactivity that persist into adulthood in the majority of the diagnosed children. Despite several risk factors during childhood predicting the persistence of ADHD symptoms into adulthood, the genetic architecture underlying the trajectory of ADHD over time is still unclear. We set out to study the contribution of common genetic variants to the risk for ADHD across the lifespan by conducting meta-analyses of genome-wide association studies on persistent ADHD in adults and ADHD in childhood separately and jointly, and by comparing the genetic background between them in a total sample of 17,149 cases and 32,411 controls. Our results show nine new independent loci and support a shared contribution of common genetic variants to ADHD in children and adults. No subgroup heterogeneity was observed among children, while this group consists of future remitting and persistent individuals. We report similar patterns of genetic correlation of ADHD with other ADHD-related datasets and different traits and disorders among adults, children, and when combining both groups. These findings confirm that persistent ADHD in adults is a neurodevelopmental disorder and extend the existing hypothesis of a shared genetic architecture underlying ADHD and different traits to a lifespan perspective

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality