258 research outputs found

    When invasion biology meets taxonomy: Clavelina oblonga (Ascidiacea) is an old invader in the Mediterranean Sea

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    Taxonomic issues often confound the study of invasive species, which sometimes are unrecognized as introduced in newly colonized areas. Clavelina oblonga Herdman, 1880 is an abundant ascidian species along the southeastern coast of the United States and the Caribbean Sea. It was introduced into the eastern Atlantic and Brazil decades ago. In the Mediterranean Sea, a similar species had been described as C. phlegraea Salfi 1929 and reported from southern Italy and Corsica. In the last few years a species of Clavelina has proliferated in the embayments of the Ebro Delta (NW Mediterranean), a zone of active bivalve culture industry where it has smothered mussel spat, leading to economic loss. We here report the morphological and genetic identity of this species, synonymizing the Atlantic C. oblonga and the Mediterranean C. phlegraea (the latter therefore is a synonym of the former). Thus, C. oblonga has existed in the Mediterranean for over 80 years, but was known under a different name. We also found this species in natural habitats in the Iberian Atlantic coast close to the Strait of Gibraltar, raising concerns about an ongoing expansion. In order to obtain information relevant for management, we monitored growth, reproductive cycles and settlement patterns of this ascidian on bivalve cultures in the Ebro Delta. Its biological cycles were markedly seasonal, with peak abundance and reproduction during the warmest months, followed by regression during the cold season. The settlement period was short, mostly concentrated in a single month each year. Avoidance of mussel and oyster seeding during late summer and early autumn can readily reduce the damage caused by this species

    Andosols of the Canary Islands (X). Vitrandepts. Mineralogical characteristics. Their interpretation and classification

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    12 páginas, 8 gráficas.Interpretation, classification and mineralogical characteristics of Vitrandepts are given by the authors. The soils of this group are typically andosoils, with a littie differenciated profil developed on very recent vitric pyroclastic materials. Primary minerals, and volcanic glasses are very abundant in the gross and fine fractions of this soil. Secondary minerals are mainly allophane. Techniques used for mineralogical identifications include X-Ray, Infrared and electron-Microscope.Peer reviewe

    A New Hydrogen Sensor Based on a Pt/GaAs Schottky Diode

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    4 páginas, 7 figuras, 1 tabla.-- PACS: 82.45.Jn; 07.07.Df; 85.30.Hi.A new hydrogen-sensitive detector based on a Pt/GaAs Schottky diode has been fabricated. The devices have beencharacterized by dark current-voltage and capacitance-voltage measurements, as a function of temperature and gas phasecomposition. At 150°C, the detection limit for hydrogen is 6 ppm in a nitrogen environment and 200 ppm in air.Peer reviewe

    Seasonal patterns of settlement and growth of introduced and native ascidians in bivalve cultures in the Ebro Delta (NE Iberian Peninsula)

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    Ascidians are important both as invasive species and as a fouling group in artificial marine habitats, causing negative impacts in aquaculture settings and the surrounding environment. The Ebro Delta is one of the major centres of bivalve production in the Mediterranean and is affected by proliferation of ascidian species (mostly introduced forms). Knowledge of the patterns of settlement and growth of the fouling species is mandatory to attempt mitigation measures. Settlement PVC plates were deployed from May to September 2015 at different depths (0.2, 1 and 2 m) in the Ebro Delta oyster aquaculture facilities. The occurrences of all species and the area cover of a selected subset of 6 species were monitored on a monthly basis from June 2015 to December 2016. Fifteen species were found, of which 10 are introduced. There were some differences between the deployed plates and the oyster ropes in species abundance and composition, likely due to differences in substrate complexity. For instance, Didemnum vexillum and Clavelina oblonga occurred in few plates in contrast to their abundance on oysters. The most abundant species were Styela plicata and Clavelina lepadiformis, which together with Ecteinascidia turbinata showed a preference to grow on plates deployed in May and June. Most of the species grew more at 0.2 m depth than at deeper plates. Thus, to minimise fouling on bivalves, spat immersion during fall and below 1 m depth is recommended. The number of occurrences and cover of the species was found to be similarly informative; suggesting that a periodic monitoring of species occurrence on replicate plates is sufficient for detecting new introduced species as soon as possible and will provide information useful for management

    Lucha frente a la Varroosis en colmenas Layens

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    111 páginas, 89 figuras, 17 tablas . -- Con la colaboración de: Mª Sonia Rodríguez Cruz, José Manuel Ordax de Castro, Raquel Arroyo Palomares, Yolanda Picó García, Juan Manuel Andrés Sánchez, Francisco Javier Fernández Santiago, Miguel Ángel Santos Oliva, Fernando Sánchez-Montejo Álvarez y Aurelio Pérez Sánchez.Actualmente la varroosis es el principal problema de la apicultura a nivel sanitario, tratándose de la enfermedad de las colonias de abejas más importante, y la única que obliga a realizar un tratamiento sistemático de la colmena para que los efectos del parásito no influyan negativamente en el rendimiento o incluso la viabilidad de la misma. Como consecuencia de la importancia de la actividad apícola en Castilla y León y dada la problemática sanitaria a la que se enfrenta el sector apícola, se justifica perfectamente la ejecución de un estudio de lucha frente a la varroosis, realizado en colmena Layens, colmena utilizada por el 80% de los apicultores españoles y mayoritaria en Salamanca. El estudio se ha ejecutado en esta provincia, que dispone del mayor número de apicultores profesionales y de colmenas y persigue que los resultados permitan a los apicultores mejorar la lucha contra esta parasitosis en sus explotaciones apícolas y mantener su viabilidad.Diputación de Salamanca. Organismo Autónomo de Empleo y Desarrollo Rural.N

    Utilization of lactose and presence of the phospho-β-galactosidase (lacG) gene in Lactococcus garvieae isolates from different sources

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    This study evaluates the utilization of lactose (Lac) and the presence of the phospho-β-galactosidase (lacG) gene as markers for distinguishing between fish (Lac-/lacG-) and dairy isolates (Lac+/lacG+) of Lactococcus garvieae, using a panel of L. garvieae isolates from different sources. None of the fish isolates produced acid from lactose (Lac-), however Lac-/lacG- isolates were observed in pigs, cows, birds and humans. Most of the dairy isolates (77.8%) were Lac+/lacG+, but some dairy isolates did not produce acid from this sugar. Data in the present study show that the ability to metabolize lactose and the presence of the lacG gene are heterogeneously scattered among L. garvieae isolates of different sources. Therefore, the use of these criteria as markers to differentiate between L. garvieae isolates of dairy and fish origin should be considered with caution. [Int Microbiol 2010; 13(4):189-193

    Allogeneic adipose tissue-derived mesenchymal stem cells in ischaemic stroke (AMASCIS-02): A phase IIb, multicentre, double-blind, placebo-controlled clinical trial protocol

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    Introduction Stroke is a serious public health problem, given it is a major cause of disability worldwide despite the spread of recanalisation therapies. Enhancement of brain plasticity with stem cell administration is a promising innovative therapy to reduce sequelae in these patients. Methods and analysis We have developed a phase IIb, multicentre, randomised, double-blind, placebo-controlled clinical trial protocol to evaluate the safety and efficacy of intravenous administration of allogeneic adipose tissue-derived mesenchymal stem cells (AD-MSCs) in patients with acute ischaemic stroke, concurrently with conventional stroke treatment. Thirty patients will be randomised on a 1:1 basis to receive either intravenous placebo or allogeneic AD-MSCs as soon as possible within the first 4 days from stroke symptom onset. Patients will be followed up to 24 months after randomisation. The primary objective is the safety assessment of early intravenous administration of allogeneic AD-MSCs by reporting all adverse events and neurological or systemic complications in both treatment groups. Secondary objectives assess efficacy of early intravenous AD-MSC treatment in acute ischaemic stroke by evaluating changes in the modified Rankin Scale and the National Institutes of Health Stroke Scale throughout the follow-up period. In addition, brain repair biomarkers will be measured at various visits. Ethics and dissemination This clinical trial has been approved by the Clinical Research Ethics Committee of La Paz University Hospital (Madrid, Spain) and by the Spanish Agency of Medication and Health Products and has been registered in Eudra CT (2019-001724-35) and ClinicalTrials.gov (NCT04280003). Study results will be disseminated through peer-reviewed publications in Open Access format and at conference presentationsThis clinical trial has been promoted by the La Paz University Hospital Institute for Health Research—IdiPAZ (La Paz University Hospital—Universidad Autónoma de Madrid) and sponsored from a competitive grant from the Carlos III Health Institute Healthcare Research Fund, and cofunded by the European Regional Development Fund (ERDF) 'A way to make Europe'/'Investing in your future' (PIC18/00016). This clinical trial has been supported by Plataforma Española de Investigación Clínica y Ensayos Clínicos, SCReN (Spanish Clinical Research Network), funded by Carlos III Health Institute-General Subdirection for Evaluation and Promotion of Research, research PT17/0017/0013; State Plan for Scientific Investigation, Technology and Innovation (2017–2020) and cofunded by European Regional Development Fund/European Social fund 'A way to make Europe'/'Investing in your future' (grant ID PT17/0017/0013

    Spin degree of freedom in two dimensional exciton condensates

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    We present a theoretical analysis of a spin-dependent multicomponent condensate in two dimensions. The case of a condensate of resonantly photoexcited excitons having two different spin orientations is studied in detail. The energy and the chemical potentials of this system depend strongly on the spin polarization . When electrons and holes are located in two different planes, the condensate can be either totally spin polarized or spin unpolarized, a property that is measurable. The phase diagram in terms of the total density and electron-hole separation is discussed.Comment: 4 pages, 3 figures, Accepted for publication in Physical Review Letter

    Effects of intravenous administration of allogenic bone marrow- and adipose tissue-derived mesenchymal stem cells on functional recovery and brain repair markers in experimental ischemic stroke

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    The electronic version of this article is the complete one and can be found online at: http://stemcellres.com/content/4/1/11Introduction: Stem cell therapy can promote good recovery from stroke. Several studies have demonstrated that mesenchymal stem cells (MSC) are safe and effective. However, more information regarding appropriate cell type is needed from animal model. This study was targeted at analyzing the effects in ischemic stroke of acute intravenous (i.v.) administration of allogenic bone marrow- (BM-MSC) and adipose-derived-stem cells (AD-MSC) on functional evaluation results and brain repair markers. Methods: Allogenic MSC (2 × 106 cells) were administered intravenously 30 minutes after permanent middle cerebral artery occlusion (pMCAO) to rats. Infarct volume and cell migration and implantation were analyzed by magnetic resonance imaging (MRI) and immunohistochemistry. Function was evaluated by the Rogers and rotarod tests, and cell proliferation and cell-death were also determined. Brain repair markers were analyzed by confocal microscopy and confirmed by western blot. Results: Compared to infarct group, function had significantly improved at 24 h and continued at 14 d after i.v. administration of either BM-MSC or AD-MSC. No reduction in infarct volume or any migration/implantation of cells into the damaged brain were observed. Nevertheless, cell death was reduced and cellular proliferation significantly increased in both treatment groups with respect to the infarct group. At 14 d after MSC administration vascular endothelial growth factor (VEGF), synaptophysin (SYP), oligodendrocyte (Olig-2) and neurofilament (NF) levels were significantly increased while those of glial fiibrillary acid protein (GFAP) were decreased. Conclusions: i.v. administration of allogenic MSC - whether BM-MSC or AD-MSC, in pMCAO infarct was associated with good functional recovery, and reductions in cell death as well as increases in cellular proliferation, neurogenesis, oligodendrogenesis, synaptogenesis and angiogenesis markers at 14 days post-infarctThis study was supported by grants from Cellerix, FIS 060575 and PS09/ 01606 (Spanish Ministry of Science), CIDEM (Center for Innovation and Business Development) and by RENEVAS (RD07/0026/2003) (Spanish Neurovascular Network), the Carlos III Research Institute and the Ministry of Science and Innovatio

    Utilization of lactose and presence of the phospho-β-galactosidase (lacG) gene in Lactococcus garvieae isolates from different sources

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    This study evaluates the utilization of lactose (Lac) and the presence of the phospho-β-galactosidase (lacG) gene as markers for distinguishing between fish (Lac-/lacG-) and dairy isolates (Lac+/lacG+) of Lactococcus garvieae, using a panel of L. garvieae isolates from different sources. None of the fish isolates produced acid from lactose (Lac-), however Lac-/lacG- isolates were observed in pigs, cows, birds and humans. Most of the dairy isolates (77.8%) were Lac+/lacG+, but some dairy isolates did not produce acid from this sugar. Data in the present study show that the ability to metabolize lactose and the presence of the lacG gene are heterogeneously scattered among L. garvieae isolates of different sources. Therefore, the use of these criteria as markers to differentiate between L. garvieae isolates of dairy and fish origin should be considered with caution
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