Co-existence of two mytilids in a heterogeneous environment: mortality, growth and strength of shell and byssus attachment

14 páginas, 1 apéndice, 5 tablas, 7 figurasThe co-existence patterns of 2 mytilid species were studied in order to evaluate the performance of the alien mussel Xenostrobus securis and the indigenous Mytilus galloprovincialis through monospecific and mixed co-habiting experiments in the Ría de Vigo (northwest Spain). Mytilus galloprovincialis was found to be the best performer in all tests. Shell growth was ~4-fold greater for the indigenous mussel when deployed without interspecific competition and regardless of density. Differences in shell growth were found to be similar within mixed populations wherein M. galloprovincialis showed greater ability for upward migratory movements on the mixed beds and distanced itself from the mud influenced layer. The alien X. securis, however, was found to inhabit underneath the M. galloprovincialis layer, which resulted in higher mortality rates. Species-specific features such as byssus filaments and lifestyle may account for such different behaviour. M. galloprovincialis secreted thicker and stronger shells and byssus regardless of their density in both monospecific and mixed experiments. This might indicate that the indigenous mussel performs better when confronted with abiotic stress or biotic pressure. The alien X. securis is currently found to establish high-density patches of individuals at the confluence of main rivers that flow into the estuary (highly heterogeneous scenario). Such behaviour favours its settlement far from the native mussel influence area. X. securis also colonises hard substrates that are not-fully occupied by other invertebrates, but its range was found to be limited by the presence of the indigenous mussel.This study was funded by the project AGL2010-16464 (Ministerio de Ciencia e Innovación, Spanish Government).Peer reviewe

Evolution and challenges in the design of computational systems for triage assistance

AbstractCompared with expert systems for specific disease diagnosis, knowledge-based systems to assist decision making in triage usually try to cover a much wider domain but can use a smaller set of variables due to time restrictions, many of them subjective so that accurate models are difficult to build. In this paper, we first study criteria that most affect the performance of systems for triage assistance. Such criteria include whether principled approaches from machine learning can be used to increase accuracy and robustness and to represent uncertainty, whether data and model integration can be performed or whether temporal evolution can be modeled to implement retriage or represent medication responses. Following the most important criteria, we explore current systems and identify some missing features that, if added, may yield to more accurate triage systems

Firewood and timber exploitation during the third and second millennia BC in Northwestern Iberia: wood resources, territories and chaîne opératoire

Human societies established productive strategies in order to obtain the material resources needed for their day‐to‐day life, including firewood and timber. These strategies were determined by the environmental supply, and also by the cultural characteristics and technical capacities of these communities. This paper presents charcoal analysis data from four Chalcolithic and Bronze Age open‐air settlements located in the northwest of the Iberian Peninsula and occupied during the third and second millennia BC. These results contribute to the knowledge of the exploitation of wooden resources, of the territories where these resources were collected, and of the firewood and timber production process. The identified wood taxa point to a diversified exploitation of the territory, where firewood and timber were collected and/or felled in the deciduous woodland, the river banks and scrubland areas. The characteristics of the wood elements used, the degree of growth ring curvature, the minimum diameter of twigs or logs, etc., as well as other data from archaeological contexts, such as the length of the postholes, were all taken into account to establish hypotheses related to the operative chaine of forest resources. The wooden resources consumed in each site allowed us to hypothesize about the territory of each community.As sociedades humanas estabelecem toda uma série de estratégias produtivas destinadas a obter os meios materiais necessários para a sua existência, entre elas, o aprovisionamento de lenha e de madeira. Estas estratégias, além de estarem condicionadas pela oferta ambiental, são igualmente resultantes das caraterísticas culturais e das capacidades técnicas das comunidades. Os dados arqueobotânicos que se apresentam procedem de vários lugares de habitação do Calcolítico e da Idade do Bronze da fachada ocidental do Noroeste peninsular com cronologias que abarcam o 3º e parte do 2º milénios AC. Os resultados obtidos permitiram identificar uma exploração diversificada dos recursos lenhosos que combinava a recolha de lenha e de madeira da floresta climácica com a proveniente das áreas de mato. As formações arbóreas situadas nas margens dos cursos de água também constituíram fonte de aprovisionamento de combustíveis e, provavelmente, de madeira. A análise dendrológica das amostras registando o grau de curvatura dos anéis de crescimento anual, o diâmetro mínimo dos ramos ou troncos consumidos, entre outras características, em inter‑relação com determinados contextos arqueológicos (dimensões dos buracos de poste, por exemplo), proporcionaram hipóteses relacionadas com a cadeia técnica‑operativa dos recursos florestais. A caracterização dos recursos usados em cada um dos casos de estudo permitiu, igualmente, colocar hipóteses sobre o território de vivência, de circulação e de exploração de cada comunidade.Fundação para a Ciência e Tecnologi

Electrochemical sensing platform with gold nanoparticles capped by PDDA for benzyl alcohol determination

An electrochemical sensor has been developed, by modifying screen-printed carbon devices (SPCE) with photochemically synthesized gold nanoparticles (AuNP), to determine benzyl alcohol, a preservative widely used in the cosmetic industry. To obtain the AuNP with the best properties for electrochemical sensing applications, the photochemical synthesis was optimized using chemometric tools. A response surface methodology based on central composite design was used to optimize the synthesis conditions, as irradiation time, and the concentrations of metal precursor and the capping/reducing agent (poly(diallyldimethylammonium) chloride, PDDA). The anodic current of benzyl alcohol on SPCE modified with the AuNP was used as response of the system. The best electrochemical responses were obtained using the AuNP generated by irradiating for 18 min a 7.20 × 10−4 mol L−1 AuCl4−-1.7% PDDA solution. The AuNP were characterized by transmission electron microscopy, cyclic voltammetry and dynamic light scattering. The nanocomposite-based sensor formed by the optimal AuNP (AuNP@PDDA/SPCE) was used to determine benzyl alcohol by linear sweep voltammetry in 0.10 mol L−1 KOH. The anodic current at + 0.017 ± 0.003 V (vs. AgCl) was used as analytical signal. Detection limit obtained under these conditions was 2.8 µg mL−1. The AuNP@PDDA/SPCE was applied to determine benzyl alcohol in cosmetic samplesOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

Development of a glass-ceramic glaze formulated from industrial residues to improve the mechanical properties of the porcelain stoneware tiles

In this research a mixture of 90%wt of industrial residues (recycled soda-lime glass and ashes from a coalpower thermal plant) have been vitrified for their use as ‘‘secondary raw material”. Then, a glaze suspen-sion was prepared to be applied on the porcelain stoneware tile. The tested pieces have been fired by aconventional porcelain cycle at 1180 °C of maximum temperature. The XRD, XRF, SEM/EDS and thedilatometric analysis have been the instrumental techniques used to characterize the material. Finally,an ecological glass-ceramic glaze perfectly fitting on porcelain ceramic tile has been produced, exhibitinga unique phase, anorthite, which ensures a high flexural strength (around 96 MPa) and a significantVickers microhardness of 250 GPa, improving the mechanical properties of a conventional the porcelainceramic tile

Arsenic distribution in a pasture area impacted by past mining activities

[EN]Former mine exploitations entail a serious threat to surrounding ecosystems as after closure of mining activities their unmanaged wastes can be a continuous source of toxic trace elements. Quite often these mine sites are found within agricultural farming areas, involving serious hazards as regards product (feed/food) quality. In this work a grazing land impacted by the abandoned mine exploitation of an arsenical deposit was studied so as to evaluate the fate of arsenic (As) and other trace elements and the potential risks involved. With this aim, profile soil samples (0–50 cm) and pasture plant species (Agrostis truncatula, Holcus annus and Leontodon longirostris) were collected at different distances (0–100 m) from the mine waste dump and analyzed for their trace element content and distribution. Likewise, plant trace element accumulation from impacted grazing soils and plant trace element translocation were assessed. The exposure of livestock grazing animals to As was also evaluated, establishing its acceptability regarding food safety and animal health. International soil guideline values for As in grazing land soils (50 mg kg−1) resulted greatly exceeded (up to about 20-fold) in the studied mining-affected soils. Moreover, As showed a high mobilization potential under circumstances such as phosphate application or establishment of reducing conditions. Arsenic exhibited relatively high translocation factor (TF) values (up to 0.32–0.89) in pasture plant species, reaching unsafe concentrations in their above-ground tissues (up to 32.9, 16.9 and 9.0 mg kg−1 in Agrostis truncatula, Leontodon longirostris and Holcus annus, respectively). Such concentrations represent an elevated risk of As transfer to the high trophic-chain levels as established by international legislation. The limited fraction of arsenite found in plant roots should play an important role in the relatively high As root-to-shoot translocation shown by these plant species. Both soil ingestion and pasture intake resulted important entrance pathways of As into livestock animals, showing quite close contribution levels. The cow acceptable daily intake (ADI) of As regarding food safety was surpassed in some locations of the study area when the species Agrostis truncatula was considered as the only pasture feed. Restrictions in the grazing use of lands with considerable As contents where this plant was the predominant pasture species should be established in order to preserve food quality. Therefore, the exposure of livestock animals to As via both soil ingestion and pasture consumption should be taken into account to establish the suitability of mining-impacted areas for gazing

Green extracellular synthesis of silver nanoparticles by Pseudomonas alloputida, their growth and biofilm-formation inhibitory activities and synergic behavior with three classical antibiotics

Bacterial resistance to antibiotics is on the rise and hinders the fight against bacterial infections, which are expected to cause millions of deaths by 2050. New antibiotics are difficult to find, so alternatives are needed. One could be metal-based drugs, such as silver nanoparticles (AgNPs). In general, chemical methods for AgNPs’ production are potentially toxic, and the physical ones expensive, while green approaches are not. In this paper, we present the green synthesis of AgNPs using two Pseudomonas alloputida B003 UAM culture broths, sampled from their exponential and stationary growth phases. AgNPs were physicochemically characterized by transmission electron microscopy (TEM), total reflection X-ray fluorescence (TXRF), infrared spectroscopy (FTIR), dynamic light scattering (DLS), and X-ray diffraction (XRD), showing differential characteristics depending on the synthesis method used. Antibacterial activity was tested in three assays, and we compared the growth and biofilm-formation inhibition of six test bacteria: Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epidermidis. We also monitored nanoparticles’ synergic behavior through the growth inhibition of E. coli and S. aureus by three classical antibiotics: ampicillin, nalidixic acid, and streptomycin. The results indicate that very good AgNP activity was obtained with particularly low MICs for the three tested strains of P. aeruginosa. A good synergistic effect on streptomycin activity was observed for all the nanoparticles. For ampicillin, a synergic effect was detected only against S. aureus. ROS production was found to be related to the AgNPs’ antibacterial activit

Expresión de E-cadherina, laminina y colágeno IV en la evolución de displasia a carcinoma epidermoide oral

Objetivos: Estudiar la pérdida o reducción de la adhesión celular mediada por E-cadherina en leucoplasias, carcinomas epidermoides y metástasis ganglionares. Estudiar la pérdida de continuidad de la expresión de laminina y colágeno IV en la membrana basal epitelial en el desarrollo biológico de las leucoplasias y carcinomas orales. Material y metodo: Hemos estudiado 124 muestras de pacientes portadores de leucoplasias y carcinomas orales con diversos diagnósticos que abarcan desde epitelio normal (13 muestras), displasias leves (2), displasias moderadas (12), carcinomas in situ (13) carcinomas microinvasores (11) Carcinoma epidermoide oral (64 muestras) y metástasis ganglionar (9). Se construyeron 7 bloques de tissue microarrays con aguja de 2mm y se realizó un estudio mediante técnica inmunohistoquímica para E-cadherina (clona 36, T.D. ABD Company), Laminina (078P, Biogenex) y Colágeno IV (PHM12, Biogenex). Resultados: En Displasias Leves y Moderadas presentan pérdida de expresión de E-cadherina, Laminina, y Colágeno IV (20%). En Carcinomas in situ y Microinvasores, presentaron pérdida de expresión de E-cadherina (73%), y en Laminina y Colágeno IV (57%). En los carcinomas epidermoides, encontramos pérdida de expresión de E-cadherina (90%) y discontinuidad en la M. basal (70%). Todas las metástasis ganglionares presentaron pérdida de E-cadherina y discontinuidad en Laminina y Colágeno IV. Conclusiones: La pérdida de expresión de E-cadherina se incrementa al aumentar el grado de displasia de las lesiones. La perdida de continuidad en la expresión de laminina y Colágeno IV sigue una evolución paralela desde displasias a metástasis ganglionares. La disminución en la expresión de los tres marcadores ha sido significativa en la evolución de las lesiones orales.Objectives: Study the loss or reduction of the cellular adhesion mediated for E-cadherin in oral leukoplakias, oral squamous cell carcinomas and metastatic nodules. Study the loss of continuity of the laminin and collagen IV expression in the epithelial basal membrane from the biological development of the oral leukoplakias and oral carcinomas. Material and method: we have studied 124 samples of patient payees leukoplakias and oral carcinomas with diverse diagnosis that embrace from normal epithelium (13 samples), mild dysplasias (2), moderate dysplasias (12), 'in situ' carcinomas (13), microinvasive carcinomas (11) oral squamous cell carcinomas (64 samples) and metastatic nodules (9). 7 blocks of tissue microarrays were built with needle of 2mm and was carried out a study by means of immunohistochemical technique for E-cadherin (clone 36, Biogenex), Laminin (078P, Biogenex) and Collagen IV (PHM12, Biogenex). Results: In Mild and Moderate Dysplasias the results present loss of E-cadherin, Laminin, and Collagen IV (20%) expression. 'in situ' and microinvasive carcinomas, the results presented loss of E-cadherin expression (73%), and loss in Laminin and Collagen IV expression (57%). In the squamous cell carcinomas , we find E-cadherin underexpression (90%) and discontinuity in the Basal Membrane. (70%). All the metastatic nodules presented loss of E-cadherin expression and discontinuity in Laminin and Collagen IV expression. Conclusions: The loss of E-cadherin expression is increased when increasing the dysplasia grade of lesions. The loss of continuity in the laminin and Collagen IV expression follow a parallel evolution from dysplasias to metastatic nodules. The underexpression of the three markers has been significant in the evolution of the oral lesions

Evaluación de resultados en el tratamiento quirúrgico de las fracturas aisladas de cabeza de radio en el adulto

Presentamos una serie de 35 pacientes intervenidos en nuestro servicio por fractura aislada de cabeza de radio. El objetivo ha sido evaluar el resultado funcional del tratamiento quirúrgico de estas fracturas en el adulto, la correlación de los diferentes sistemas de evaluación de resultados y determinar los factores pronóstico. Las fracturas se clasificaron según Mason evaluando los resultados utilizando la escala de valoración del hospital par cirugía especial (HSSA) de Inglis y Pellici, el índice de clasificación funcional de Broberg y Morrey y la escala de evaluación funcional del codo de la Clínica Mayo. En más del 80% de los casos se obtuvieron resultados buenos ó excelentes, con una flexión media de 139% y un déficit de extensión de 10º. Los tres métodos de valoración mostraron un índice de concordancia estadísticamente significativo resultado por tanto ser equiparables. El retraso en la cirugía resultó ser un factor pronóstico en el resultado final (p<0.05) mientras que el tipo de fractura y de cirugía muestran tendencia a influir en el resultado final.Functional outcome after surgery for isolated radial head fractures in adults was assessed using three different outcome assessment approaches and favourable prognostic factors were determined. Thirty-five patients with radial head fractures were operated. Fractures were grouped according to the Mason classification, and the results obtained were assessed by means of the hospital for special surgery assessment (HSSA) system. Broberg and Morrey functional classification index and the Mayor Clinic elbow functional in over 80% of cases, with an average flexion of 139 degrees and an extension defect of 10 degrees. All three assessment system yielded statistically significant concordant scores, and was thus considered to be equivalent. Surgical delay proved to be a significant prognostic factor of the end result (p<0.05), while the type of fracture and surgery employed tended to influence outcome