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This work presents the study of the effect of 3 wt% V2O5, Na2O, CaO and FeTiO3 on the stabilization of Aluminum Titanate (Al2TiO5). Samples were prepared by the conventional processing route of dry ball milling followed by wet mixing and final uniaxial pressing at 300 MPa before sintering at 1400ºC. Specimens were heat treated at 1000ºC during 12 and 20 hours in order to evaluate Al2TiO5 decomposition. The microstructure was observed by Scanning Electron Microscopy (SEM) and phases present were determined by X Ray Diffraction (XRD) and Energy Dispersive Spectroscopy (EDS). It has been elucidated the effect of FeTiO3 (Ilmenite) on the improvement of the formation and thermal stabilization of Al2TiO5.En este trabajo se presenta el estudio del efecto de la adición de 3% en peso de V2O5, Na2O, CaO y FeTiO3 en la estabilización térmica del Titanato de Aluminio (Al2TiO5). El procesamiento de las muestras fue mediante la molienda en seco de los polvos de alúmina y titania, mezcla vía húmeda con alcohol isopropílico y sinterización a 1400ºC de los compactos prensados uniaxialmente a 300 MPa. Una vez sinterizadas las muestras fueron tratadas térmicamente a 1000ºC durante 12 y 20 horas para evaluar la descomposición del Al2TiO5. La microestructura de las probetas se analizó mediante Microscopía Electrónica de Barrido (MEB) y las fases presentes se determinaron mediante Difracción de Rayos X (DRX) y Espectroscopía de Rayos X por dispersión de Energía (EDX). Esta caracterización evidenció el efecto beneficioso de la adición de FeTiO3 (Ilmenita) en la formación y estabilización térmica del Al2TiO5. more...

Introduction: Childhood excess weight is a growing public health problem. The aim of this study was to assess temporal trends in the prevalence of overweight, obesity and central obesity in schoolchildren aged 6-9 years in Spain between 2011 and 2019 based on demographic and socioeconomic characteristics., Methodology: The analysis included data from the 2011, 2015 and 2019 rounds of the cross-sectional observational and descriptive ALADINO study in schoolchildren of both sexes aged 6-9 years. We conducted a descriptive analysis of the trends in the prevalence of overweight and obesity (defined according to the criteria of the World Health Organization and the International Obesity Task Force) and of central obesity, in addition to associated demographic and socioeconomic variables., Results: Between 2011 and 2019, the prevalence of overweight (WHO criteria) decreased in boys aged 6, 7 and 8 years (by -5.4%, -5.7% and -5.3%, respectively) and boys whose parents had a higher educational attainment (by -5.3%). In relation to the socioeconomic level, overweight in boys declined at all income levels. However, between 2011 and 2019, both the prevalence of overweight in girls and the prevalence of obesity (applying the WHO and IOTF criteria) and the prevalence of central obesity in both sexes remained stable., Conclusions: The prevalence of overweight and the prevalence of obesity in schoolchildren aged 6-9 years in Spain remain high. Between 2011 and 2019, the prevalence of overweight in children aged 6-8 years and in children whose parents had university degrees decreased, whereas obesity in boys, overweight and obesity in girls and central obesity in both sexes remained stable., (Copyright © 2024 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.) more...

Introduction: Childhood obesity is inversely associated with household socioeconomic status in high-income countries. Our aim was to explore the association between childhood weight status and household socioeconomic status in Spain in relation to family characteristics, perceptions and lifestyle habits and the school environment., Methods: We performed a descriptive analysis of child weight status according to family socioeconomic factors and mediating variables based on data from the ALADINO 2019 study in a sample of 16,665 schoolchildren representative of the population aged 6-9 years in Spain., Results: The prevalence of childhood obesity in households with low socioeconomic status (26.8% boys; 20.4% girls) was, in both sexes, twice as high as in those with higher socioeconomic status (12.1% boys; 8.7% girls). Unhealthy eating habits, sedentary lifestyles (mainly in girls) and the presence of screens in the bedroom (more prevalent in boys) were more frequent in school-aged children from low-income households. On the other hand, in the most disadvantaged households, a history of breastfeeding and physical activity (especially in girls) were less frequent. Similarly, schools attended by children from low-income households were less likely to have their own kitchens and indoor gymnasiums or offer sports activities., Conclusion: A lower household socioeconomic status was associated with poorer dietary and physical activity habits and certain characteristics of the family and school environments that mediate the inverse association between household socioeconomic status and the prevalence of childhood obesity. Girls were less physically active and reported more sedentary lifestyles, while boys had greater access to screens. Interventions to combat childhood obesity should address the identified inequalities., (Copyright © 2023 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.) more...

Coastal areas are affected by multiple stressors like climate change and endocrine disruptors (EDCs). In the laboratory, we investigated the combined effects of increased temperature and EDCs (drospirenone and mercury) on the fitness and gonads' maturation dynamics of the marine gastropod Nucella lapillus for 21 days. Survival was negatively affected by all the stressors alone, while, in combination, a synergistic negative effect was observed. Both chemicals, as single factors, did not cause any effect on the maturation stage of ovaries and testis. However, in the presence of a higher temperature, it was clear a delay in the maturation stage of the ovaries, but not in the testis, suggesting a higher negative impact of the stressors in females than in males. In summary, drospirenone caused a low negative impact in aquatic species, like gastropods, but in combination with other EDCs and/or increased temperature can be a matter of concern., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Patricia Cardoso reports financial support was provided by Fundação para a Ciencia e Tecnologia. Patricia Cardoso reports a relationship with Fundação para a Ciência e Tecnologia that includes: employment and funding grants., (Copyright © 2023. Published by Elsevier Ltd.) more...

Mapping species' geographical distribution is fundamental for understanding current patterns and forecasting future changes. Living on rocky shores along the intertidal zone, limpets are vulnerable to climate change, as their range limits are controlled by seawater temperature. Many works have been studying limpets' potential responses to climate change at local and regional scales. Focusing on four Patella species living on the rocky shores of the Portuguese continental coast, this study aims to predict climate change impacts on their global distribution, while exploring the role of the Portuguese intertidal as potential climate refugia. Ecological niche models combine occurrences and environmental data to identify the drivers of these species' distributions, define their current range, and project to future climate scenarios. The distribution of these limpets was mostly defined by low bathymetry (intertidal) and the seawater temperature. Independent of the climate scenario, all species will gain suitable conditions at the northern distribution edge while losing in the south, yet only the extent of occurrence of P. rustica is expected to contract. Apart from the southern coast, maintenance of suitable conditions for these limpets' occurrence was predicted for the western coast of Portugal. The predicted northward range shift follows the observed pattern observed for many intertidal species. Given the ecosystem role of this species, attention should be given to their southern range limits. Under the current upwelling effect, the Portuguese western coast might constitute thermal refugia for limpets in the future., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Francisco Arenas reports financial support was provided by Foundation for Science and Technology., (Copyright © 2023 Elsevier Ltd. All rights reserved.) more...

Comparing temporal patterns of distribution and abundance of target organisms between protected and harvested shores is essential to assess the extant effectiveness of marine protected areas (MPAs) and whether it is maintained through time. By means of an adapted Beyond-BACI approach, we compared the short- and long-term patterns of variation in the abundance of the sea urchin Paracentrotus lividus and the mussel Mytilus galloprovincialis at a protected shore (within the Parque Litoral Norte MPA, Portugal) and at three adjacent shores subject to intense harvesting over a decadal interval. Despite the existence of the MPA for more than 30 years, we did not obtain clear evidence of its persistent or recent effectiveness on intertidal species of commercial interest. We suggest the need for refining management options along the northern Portuguese coast, possibly by better enforcing current regulations and reconsidering the present design of protection schemes. Moreover, the adopted analytical approach may represent a methodological reference for similar investigations in systems where the perturbation of interest (protection or disturbance) would not occur at a given time during the course of the study, but has been operating since before the first sampling occasion and maintained until subsequent surveys., (Copyright © 2021 Elsevier Ltd. All rights reserved.) more...

Alterations of the physical-chemical properties of the oceans due to anthropogenic activities are, at present, one of the most concerning environmental issues studied by researchers. One of these issues is ocean acidification, mainly caused by overproduction and release of carbon dioxide (CO 2 ) from anthropogenic sources. Another component of environmental degradation is related to the production and release of potential toxic compounds, namely active pharmaceutical ingredients, into the aquatic environment that, combined with oceanic acidification, can cause unpredictable and never before considered deleterious effects on non-target marine organisms. Regarding this issue, the hereby study used predictions of future ocean acidification to simulate realistic scenarios of environmental exposure to a common therapeutic drug, salicylic acid (SA), in the marine gastropod Gibbula umbilicalis under different pH values. This species was exposed to a range of pH values (8.2, 7.9 and 7.6), and to already reported environmentally realistic concentrations (5, 25 and 125 μg/L) of SA. To evaluate the effects of these environmental stressors, key physiological biomarkers (GSTs, CAT, TBARS, AChE and COX) and shell hardness (SH) were quantified. Results from the present study showed that CAT and GSTs activities were enhanced by SA under water acidification; increased lipid peroxidation was also observed in organisms exposed to SA in more acidic media. In addition, the hereby study demonstrated the neurotoxic effects of SA through the inhibition of AChE. Effects were also observed in terms of COX activity, showing that SA absorption may be affected by water acidification. In terms of SH, the obtained data suggest that SA may alter the physical integrity of shells of exposed organisms. It is possible to conclude that the combination of seawater acidification and exposure to toxic xenobiotics (namely to the drug SA) may be strenuous to marine communities, making aquatic biota more susceptible to xenobiotics, and consequently endangering marine life in an unpredictable extent., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.) more...

Here, we present the characterization of three iPSC lines derived from dermal fibroblasts of old healthy subjects. Fibroblasts were reprogrammed using Sendai viral vectors encoding OCT4, SOX2, KLF4 and c-MYC. The iPSCs expressed endogenous pluripotency markers, could generate the three germ layers (ectoderm, mesoderm and endoderm), maintained a stable karyotype, and were free from Sendai vectors and reprogramming factors. These integration-free iPSCs can serve for establishing control cell cultures in studies searching for phenotypes and mechanisms that could potentially be dysregulated in degenerative diseases., Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.) more...

The L444P mutation in the GBA1 gene which encodes β-glucocerebrosidase-1, is a major risk factor for developing Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We report the generation and characterization of an induced pluripotent stem cell (iPSC) line derived from a female PD patient carrying the L444P/wt mutation. The iPSC line presented a normal morphology, expressed endogenous pluripotency markers, could be differentiated into endodermal, mesodermal and ectodermal cells, was free from Sendai vectors and reprogramming factors, had a normal karyotype and maintained the original GBA1 genotype. Thus, this iPSC line can serve to establish cellular models of PD., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.) more...

World's oceans are warming, and recent studies suggest that the Iberian upwelling system may be weakening. To understand the potential consequences of both trends, six intertidal seaweeds that recently followed opposite upward and downward abundance shifts in the Iberian upwelling region were exposed for six weeks to conditions simulating present and warmed scenarios, combined with nutrient treatments emulating the influence and absence of the upwelling. Unlike expectations, a high nutrient supply did not ameliorate the effects of warming. Instead, warming slowed down growth in four seaweeds and accelerated the photosynthesis of downward seaweeds only if nutrients were abundant. In a weakened upwelling scenario, nutrient limitation might more strongly influence the performance of both upward and downward seaweeds than warming. With a normally functioning upwelling, warming might be more detrimental to the performance of some downward seaweeds as they might would lose their ability to benefit from the extra nutrient input., (Copyright © 2019 Elsevier Ltd. All rights reserved.) more...

Mutations in the GBA1 gene, which encodes the lysosomal enzyme Glucocerebrosidase1 are major risk factors for Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We have generated induced pluripotent stem cells (iPSCs) from fibroblasts of four PD patients carrying the N370S/wt or the L444P/wt heterozygous mutations in GBA1. The iPSCs presented a normal morphology, expressed endogenous pluripotency markers and could be differentiated into endodermal, mesodermal and ectodermal cells. These iPSCs were free from Sendai viral vectors and reprogramming factors, had a normal karyotype and maintained the original GBA1 genotype., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.) more...

We aimed to show how the predicted pH decrease in the ocean would alter the toxicity, bioconcentration and dietary transfer of trace metal copper on seagrass ecosystems, on a short-term basis. Seagrass Zostera noltei was exposed to two pH levels (8.36 and 8.03) and three copper levels (nominal concentrations, <3, 30 and 300 μg Cu L -1 ) in a factorial design during 21 days, while Gammarus locusta amphipods were continuously fed with the treated seagrass leaves. We found that the toxicity and bioconcentration of copper in seagrasses were not affected by pH, yet complex copper-pH interactions were observed in the seagrass photosynthesis. We demostrated that seagrasses can act as a copper source in the food web via direct consumption by herbivores. Future research need to investigate the interactive effects on a long-term basis, and to include biochemical and molecular endpoints to provide additional insights to the complex phisiological interactions observed., (Copyright © 2019. Published by Elsevier Ltd.) more...

Freshwater bivalves have suffered major global declines, being the introduction of invasive alien species (IAS) an important, but not well studied, mechanism of threat. This study assessed the predator-prey relationship between two non-native crayfish species (Procambarus clarkii and Pacifastacus leniusculus) and three native (Anodonta anatina, Potomida littoralis and Unio delphinus) and one non-native (Corbicula fluminea) freshwater bivalve species through experiments in laboratory and validation under natural conditions (Sabor River basin, Portugal). All native bivalve species were preyed both in laboratory and in the field; however, both crayfish species were unable to prey C. fluminea. Predation was dependent on crayfish and bivalve species but was not affected neither by crayfish nor bivalve sizes. In the laboratory, the most preyed species by both crayfishes was A. anatina. On average, this species was preyed at least 12% more than other species, when crayfishes had a choice. Similar results were found in the field. We also found signs of competition between both crayfishes, being P. clarkii more dominant and aggressive as this species, on average, manipulated the bivalves 63.6% more times and 24:33 min longer than P. leniusculus, and initiated 55.8% more agnostic bouts. Our results support the idea that P. clarkii and P. leniusculus can affect native freshwater bivalves, but clear interspecific differences were detected. Both crayfishes may have direct and indirect impacts on bivalve populations by increasing mortality or by reducing their fitness. In addition, since both crayfishes do not prey C. fluminea, they offer this IAS another advantage over native bivalves. Given the widespread distribution of both P. clarkii and P. leniusculus and the threatened status of many freshwater bivalves, the dynamics and impacts of this relationship should be taken in account in the implementation of management measures devoted to the conservation of native freshwater bivalves., (Copyright © 2018 Elsevier B.V. All rights reserved.) more...

Innate immune status of the sea urchin Paracentrotus lividus population from two different rocky shore beaches in the northern Portuguese coast was evaluated for a period of one year. Although some ecological studies regarding the effect of toxics on the immune parameters of the sea urchin were made in Portuguese waters, there is a current lack of knowledge concerning their immune status all over the year. In perspective of a changing ecosystem in these waters due to global warming and colonization of new species, it is important to assess the status of the major species living in the area. In this way, immune parameters such as total protein content, nitric oxide concentration, haemolytic activity, protease activity, lysozyme concentration and bactericidal activity were evaluated in the perivisceral coelomic fluid, and were correlated with the gonadal index of the population and water parameters. Also, the spawning period can upset some immune status parameters, and others such as haemolytic activity and bactericidal activity against Vibrio anguillarum, showed a clear correlation with the gonad maturation status. The knowledge of the basal immune status of the species could serve as ecological indicator of some stress agent or contaminant into the field; also, coelomic fluid is suggested as good quality marker to assess the immune status of sea urchins., (Copyright © 2018 Elsevier Ltd. All rights reserved.) more...

Paracentrotus lividus is a common and intensely harvested sea urchin at several European locations, including the Mediterranean Sea and the Atlantic coast of the Iberian Peninsula. The increasing human pressure on this resource due to the growing demand and market value of sea urchin gonads as seafood raises concerns on the ecological sustainability of present fisheries, which are showing a technological improvement and an expansion towards previously non-harvested areas. We examined the abundance of P. lividus of both commercial and non-commercial size before, during and after the harvesting season (from October to April) in the rocky shallow subtidal habitat along the northern Portuguese coast. The abundance of commercial (≥50 mm in test diameter) P. lividus individuals increased in the harvesting season, but drastically dropped by about 90% in the after-harvesting period. Such a pattern was consistent among three rocky shores spanning about 65 km of coast. The multivariate population structure and most size classes of non-commercial sea urchins did not differ depending on the period. The only exception was Class 4 (test diameter between 30 and 40 mm), which was more abundant in the harvesting than in the before- and, further, the after-harvesting period, but only at one shore. Very small (Class 1, test diameter below 10 mm) urchins were never found. The present findings suggest that human harvesting may cause considerable reductions in the abundance of target P. lividus, but that such an effect would not be evident concomitantly with harvesting, but in the subsequent period. Even if just under a precautionary principle, protection strategies focused on sea urchin populations and the harvesting period are advisable to contribute to maintain a sustainable local fishery of P. lividus populations that are likely to be negatively affected also by other natural and anthropogenic perturbations., (Copyright © 2018 Elsevier Ltd. All rights reserved.) more...

Poor physiological acclimatization to climate change has led to shifts in the distributional ranges of various species and to biodiversity loss. However, evidence also suggests the relevance of non-climatic physical factors, such as light, and biotic factors, which may act in interactive or additive way. We used a mechanistic approach to evaluate the ecophysiological responses of four seaweed species (three dominant intertidal fucoids, Fucus serratus, Ascophyllum nodosum, Bifurcaria bifurcata, and the invasive Sargassum muticum) to different conditions of grazing, light irradiance and ultraviolet (UV) radiation. We performed a large-scale mesocosm experiment with a total of 800 individual thalli of macroalgae. The factorial experimental design included major algal traits, photoacclimation, nutrient stoichiometry and chemical defence as response variables. Few significant effects of the factors acting alone or in combination were observed, suggesting a good capacity for acclimatization in all four species. The significant effects were generally additive and there were no potentially deleterious synergistic effects between factors. Fucus serratus, a species currently undergoing a drastic contraction of its southern distribution limit in Europe, was the most strongly affected species, showing overall lower photosynthetic efficiency than the other species. The growth rate of F. serratus decreased when UV radiation was filtered out, but only in the presence of grazers. Moreover, more individuals of this species tended to reach maturity in the absence of grazers, and the nitrogen content of tissues decreased under full-spectrum light. Only the phlorotannin content of tissues of B. bifurcata and of exudates of A. nodosum, both slow-growing species, were positively affected by respectively removal of UVB radiation and the presence of grazers. The findings for S. muticum, a well-established invasive seaweed across European coasts, suggested similar physiological response of this fast-growing species to different levels of grazing activity and light quality/intensity. As expected, this species grew faster than the other species. Bifurcaria bifurcata and A. nodosum only showed minor effects of light quality and grazing on phlorotannins content, which suggests good resistance of these two long-lived species to the experimental conditions. Mechanistic approaches that are designed to analyse interactive effects of physical and biotic factors provide an understanding of physiological responses of species and help to improve the confidence of predictive distribution models., (Copyright © 2018 Elsevier Ltd. All rights reserved.) more...

Since the past century, rising CO 2 levels have led to global changes (ocean warming and acidification) with subsequent effects on marine ecosystems and organisms. Macroalgae-herbivore interactions have a main role in the regulation of marine community structure (top-down control). Gradients of warming prompt complex non-linear effects on organism metabolism, cascading into altered trophic interactions and community dynamics. However, not much is known on how will acidification and grazer assemblage composition shape these effects. Within this context, we aimed to assess the combined effects of warming gradients and acidification on macroalgae-herbivore interactions, using three cosmopolitan species, abundant in the Iberian Peninsula and closely associated in nature: the amphipod Melita palmata, the gastropod Gibbula umbilicalis, and the green macroalga Ulva rigida. Under two CO 2 treatments (ΔCO 2 ≃ 450 μatm) across a temperature gradient (13.5, 16.6, 19.9 and 22.1 °C), two mesocosm experiments were performed to assess grazer consumption rates and macroalgae-herbivore interaction, respectively. Warming (Experiment I and II) and acidification (Experiment II) prompted negative effects in grazer's survival and species-specific differences in consumption rates. M. palmata was shown to be the stronger grazer per biomass (but not per capita), and also the most affected by climate stressors. Macroalgae-herbivore interaction strength was markedly shaped by the temperature gradient, while simultaneous acidification lowered thermal optimal threshold. In the near future, warming and acidification are likely to strengthen top-down control, but further increases in disturbances may lead to bottom-up regulated communities. Finally, our results suggest that grazer assemblage composition may modulate future macroalgae-herbivore interactions., (Copyright © 2017 Elsevier Ltd. All rights reserved.) more...

Differences in the structure and functioning of intensively urbanized vs. less human-affected systems are reported, but such evidence is available for a much larger extent in terrestrial than in marine systems. We examined the hypotheses that (i) urbanization was associated to different patterns of variation of intertidal assemblages between urban and extra-urban environments; (ii) such patterns were consistent across mainland and insular systems, spatial scales from 10scm to 100skm, and a three months period. Several trends emerged: (i) a more homogeneous distribution of most algal groups in the urban compared to the extra-urban condition and the opposite pattern of most invertebrates; (ii) smaller/larger variances of most organisms where these were, respectively, less/more abundant; (iii) largest variability of most response variables at small scale; (iv) no facilitation of invasive species by urbanization and larger cover of canopy-forming algae in the insular extra-urban condition. Present findings confirm the acknowledged notion that future management strategies will require to include representative assemblages and their relevant scales of variation associated to urbanization gradients on both the mainland and the islands., (Copyright © 2016 Elsevier Ltd. All rights reserved.) more...

Aim: Cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS+HIPEC) has been proposed as treatment for advanced epithelial ovarian carcinoma (EOC). No consensus exists on when to administer CRS+HIPEC during the natural history of the disease, namely, as upfront therapy, at first recurrence, or at second or subsequent recurrence., Patients and Methods: We analyzed a series of patients with advanced EOC collected prospectively in an institution with a peritoneal malignant disease treatment program. Patients were treated with CRS+HIPEC upfront, at first recurrence, and at second or subsequent recurrence., Results: We treated 42 patients: 15 upfront, 19 at first recurrence, and 8 at second or subsequent recurrence. Cytoreduction was complete (CC0) in 75% of cases; residual disease was <2.5 mm (CC1) in 25%. Severe morbidity (CTCAE v.3.0, grade 3-4) was 26%, and hospital mortality was 7%. After a median follow-up of 24 months, median overall survival was 77.8 months for patients treated upfront, 62.8 months for patients treated at first recurrence, and 35.7 months for patients treated at second or subsequent recurrence. Disease-free survival was 21.1 months, 18 months, and 5.7 months, respectively. Overall survival in the upfront and first recurrence groups was similar, and statistically significant differences with the second recurrence group were identified (p<0.03)., Conclusions: Treatment of advanced EOC using CRS+HIPEC is promising in terms of overall survival and disease-free survival when administered as upfront and at first recurrence therapy. These results warrant further evaluation in a randomized trial., (Copyright © 2013 Elsevier Ltd. All rights reserved.) more...

Ecosystem engineers such as mussels may affect strongly both the structure of benthic assemblages and the ecosystem functioning. The black-pygmy mussel Limnoperna securis is an invasive species that is spreading along the Galician coast (NW Spain). Its current distribution overlaps with the distribution of the commercial native mussel species Mytilus galloprovincialis, but only in the inner part of two southern Galician rias. Here, we analysed the assemblages associated with clumps of the two mussel species and evaluated if the invasive species increased complexity of habitat. To measure complexity of clumps we used a new method modified from the "chain and tape" method. Results showed that the identity of the mussel influenced macrofaunal assemblages, but not meiofauna. L. securis increased the complexity of clumps, and such complexity explained a high percentage of variability of macrofauna. The shift in dominance from M. galloprovincialis to L. securis may alter habitat structure and complexity, affecting the macrofaunal assemblages with unpredictable consequences on trophic web relations., (Copyright © 2013 Elsevier Ltd. All rights reserved.) more...

Spatial patterns of non-indigenous species show scale-dependent properties. Sargassum muticum is an invasive macroalga widely distributed along the Atlantic Iberian Peninsula. Despite being quite abundant from Norway to South Portugal, there is little information about its patterns of distribution, particularly at a large spatial scale (i.e. thousands of kilometres). Here, we examined the spatial variation in the invasion success of S. muticum from rockpools at multiple spatial scales using a hierarchical design. In addition, we analysed how the richness of native assemblages was related to its invasion success and how this relationship changed over different scales. Most of the variation in the invasion success was found at the smallest scales of pool and plot. Furthermore, the invasibility of native macroalgal assemblages was related to the native species richness, but causes that determined invasion success could not be separated from the effects provoked by the invader. Results suggest that small-scale (centimetres to metres) processes contribute considerably to the heterogeneity of S. muticum invasion success., (Copyright © 2013 Elsevier Ltd. All rights reserved.) more...

Phosphoenolpyruvate carboxykinases, depending on the enzyme origin, preferentially use adenine or guanine nucleotides as substrates. In this work, analyses of the substrate specificity of the Saccharomyces cerevisiae ATP-dependent enzyme have been carried out. Kinetics studies gave relative values of k(cat)/K(m) for the nucleoside triphosphate complexes in the order ATP>>GTP>ITP>UTP>CTP. For the nucleoside diphosphate complexes the order is ADP>>GDP>IDP congruent withUDP>CDP. This shows that the enzyme has a strong preference for ADP (or ATP) over other nucleotides, being this preference about an order of magnitude higher for the diphosphorylated than for the triphosphorylated nucleosides. The calculated binding free energies (kcalmol(-1)) at 25 degrees C are 7.39 and 6.51 for ATP and ADP, respectively. These values decrease with the nucleotide structure in the same order than the kinetic specificity. The binding energy for any triphosphorylated nucleoside is more favourable than for the corresponding diphosphorylated compound, showing the relevance of the P(gamma) for nucleotide binding. Homology models of the adenine and guanine nucleotides in complex with the enzyme show that the base adopts a similar conformation in the diphosphorylated nucleosides while in the triphosphorylated nucleosides the sugar-base torsion angle is 61 degrees for ATP and -53 degrees for GTP. Differences are also noted in the distance between P(beta) and Mn2+ at site 1. This distance is almost the same in the ATP, GTP, and UTP complexes, however in the ADP, GDP and UDP complexes it is 2.9, 5.1, and 7A, respectively. Experimental data obtained with a Thr463Ala mutant enzyme agree with molecular simulation predictions. The results here presented are discussed in terms of the proposed interactions of the nucleotides with the protein. more...