303 research outputs found

    Productos de alfarería de Cerro Macareno, Sevilla : naturaleza y procedencia de las ánforas y otros objetos cerámicos. Siglos VIII al III a. J.C.

    Get PDF
    Son muchos los métodos empleados para el estudio de las arcillas y de los productos cerámicos, contribuyendo de distinta manera, aunque complementaria, en el conocimiento de la composición, procedencia de los materiales, tecnología empleada en su elaboración y en general en todos aquellos procesos que se pudieron seguir en la tibricación del objeto cerámico. Estos métodos pueden ser, bien destructivos, aunque utilizando cantidades muy pequeñas de muestra, o bien no destructivos, cada vez más empleados en la investigación moderna. En el estudio de los materiales cerámicos, bien sea el soporte, o bien sea la pintura que ha servido para decorarlo, se emplea el análisisq\límico tradicional cualitativo y cuantitativo. Para este último se emplea cada \leimás la técnica de la absorción atómica. Asimismo, se emplean los siguientes métodos de análisis por vía física: La espectroscopía de emisión en el ultravioleta, que permite obtener un espectro de emisión en el que la parte más frecuentemente utilizada se sitúa entre 200 y 400 nm (ultravioleta). La espectrometría de fluorescencia de rayos X es una técnica desde hace tiempo utilizada. El método tiene poca sensibilidad para elementos tales como el cobre, níquel, cinc o hierro, a causa del «ruido de fondo» que el mismo aparato emite. La microfluorescencia permite operar directamente sobre una capa de pintura y su análisis no es destructivo. La microsonda electrónica es una aplicación de los principios y de la técnica de la espectrografía de emisión de rayos X. Su poder separador es infinitamente superior al del mejor instrumento óptico. La activación por neutrones, que precisa de una fuente generadora de estas radiaciones (pila atómica), es, por tanto, de muy difícil empleo. En España se utiliza la pila atómica de la Junta de Energía Nuclear. Este análisis permite determinar los elementos mayores, menores y trazas existentes en los objetos cerámicos y en los pigmentos. Es de un gran interés para conocer la procedencia de los materiales empleados, detectando el posible o posibles yacimientos de las arcillas utilizadas. La difracción de rayos X determina la estructura cristalina de los elementos y compuestos químicos ya sean orgánicos o inorgánicos, si bien la técnica no es válida para los compuestos amorfos. Para el estudio de aquellos materiales en los que la pintura se encuentre unida al soporte mediante lacas, gomas o barnices se emplean métodos de absorción en el infrarrojo, así como la cromatografía en fase gaseosa. Los métodos seguidos que se enumeran en el siguiente apartado nos han permitido identificar la procedencia y naturaleza de las arcillas utilizadas en los objetos cerámicos objeto de este estudio.Peer reviewe

    Materias primas y datos tecnológicos de piezas cerámicas antiguas del yacimiento arqueológico de Cerro Macareno (Sevilla)

    Get PDF
    14 páginas, 5 figuras, 7 tablas, 7 referencias.[EN]: A study of twenty eight fragments of amphoras from the archaeological bed of Cerro Macareno (Sevilla) has been done by chemical, physicochemical, X-ray diffraction and thermal methods, in order to establish the nature and provenance of the raw materials and the technological aspects of their fabrication. All the data lead to the conclusion that four of the pieces were probably imported from the Palestine-Phoenicie; the rest were made out of raw materials from the surrounding areas of Cerro Macareno. Most of the pieces were fired below 700°C, only four of them at about 700-750°C, and the other seven, probably from 800-850°C.[ES]: Se estudian la composición química y mineralógica, contenido en determinados elementos escasos, materias primas y temperaturas probables de cocción empleadas en la fabricación de un conjunto de 25 fragmentos de ánforas del yacimiento arqueológico de Cerro Macareno (Sevilla). Los métodos empleados fueron análisis químico, difracción de rayos-X, A.T.D., análisis por activación neutrónica y pruebas de cocción intermitente por calentamiento de cien en cien grados, desde 400° a 1.100° C seguido en cada caso de estudios por difracción de rayos-X y de observación de los cambios de color y aspecto de los cortes de las piezas. De todo ello se concluye que cuatro de las piezas estudiadas son de origen importado (Palesti-na-Fenicia), estando fabricadas las restantes con materiales procedentes de los aluviones del Guadalquivir, en las inmediaciones del Cerro Macareno. Del total de las piezas, 17 se cocieron probablemente a temperaturas inferiores a 700°C, cuatro a 700-750° C y siete a 800-850°C.Peer reviewe

    The ROCK inhibitor Fasudil prevents chronic restraint stress-induced depressive-like behaviors and dendritic spine loss in rat hippocampus

    Get PDF
    Indexación: Web of Science; Scopus.Background: Dendritic arbor simplification and dendritic spine loss in the hippocampus, a limbic structure implicated in mood disorders, are assumed to contribute to symptoms of depression. These morphological changes imply modifications in dendritic cytoskeleton. Rho GTPases are regulators of actin dynamics through their effector Rho kinase. We have reported that chronic stress promotes depressive-like behaviors in rats along with dendritic spine loss in apical dendrites of hippocampal pyramidal neurons, changes associated with Rho kinase activation. The present study proposes that the Rho kinase inhibitor Fasudil may prevent the stress-induced behavior and dendritic spine loss. Methods: Adult male Sprague-Dawley rats were injected with saline or Fasudil (i.p., 10 mg/kg) starting 4 days prior to and maintained during the restraint stress procedure (2.5 h/d for 14 days). Nonstressed control animals were injected with saline or Fasudil for 18 days. At 24 hours after treatment, forced swimming test, Golgi-staining, and immuno-western blot were performed. Results: Fasudil prevented stress-induced immobility observed in the forced swimming test. On the other hand, Fasudiltreated control animals showed behavioral patterns similar to those of saline-treated controls. Furthermore, we observed that stress induced an increase in the phosphorylation of MYPT1 in the hippocampus, an exclusive target of Rho kinase. This change was accompanied by dendritic spine loss of apical dendrites of pyramidal hippocampal neurons. Interestingly, increased pMYPT1 levels and spine loss were both prevented by Fasudil administration. Conclusion: Our findings suggest that Fasudil may prevent the development of abnormal behavior and spine loss induced by chronic stress by blocking Rho kinase activity.https://academic.oup.com/ijnp/article/20/4/336/263217

    Thermodynamics of low dimensional spin-1/2 Heisenberg ferromagnets in an external magnetic field within Green function formalism

    Full text link
    The thermodynamics of low dimensional spin-1/2 Heisenberg ferromagnets (HFM) in an external magnetic field is investigated within a second-order two-time Green function formalism in the wide temperature and field range. A crucial point of the proposed scheme is a proper account of the analytical properties for the approximate transverse commutator Green function obtained as a result of the decoupling procedure. A good quantitative description of the correlation functions, magnetization, susceptibility, and heat capacity of the HFM on a chain, square and triangular lattices is found for both infinite and finite-sized systems. The dependences of the thermodynamic functions of 2D HFM on the cluster size are studied. The obtained results agree well with the corresponding data found by Bethe ansatz, exact diagonalization, high temperature series expansions, and quantum Monte Carlo simulations.Comment: 11 pages, 14 figure

    Olive phenology as a sensitive indicator of future climatic warming in the Mediterranean

    Get PDF
    Experimental and modelling work suggests a strong dependence of olive flowering date on spring temperatures. Since airborne pollen concentrations reflect the flowering phenology of olive populations within a radius of 50 km, they may be a sensitive regional indicator of climatic warming. We assessed this potential sensitivity with phenology models fitted to flowering dates inferred from maximum airborne pollen data. Of four models tested, a thermal time model gave the best fit for Montpellier, France, and was the most effective at the regional scale, providing reasonable predictions for 10 sites in the western Mediterranean. This model was forced with replicated future temperature simulations for the western Mediterranean from a coupled ocean-atmosphere general circulation model (GCM). The GCM temperatures rose by 4·5 °C between 1990 and 2099 with a 1% per year increase in greenhouse gases, and modelled flowering date advanced at a rate of 6·2 d per °C. The results indicated that this long-term regional trend in phenology might be statistically significant as early as 2030, but with marked spatial variation in magnitude, with the calculated flowering date between the 1990s and 2030s advancing by 3–23 d. Future monitoring of airborne olive pollen may therefore provide an early biological indicator of climatic warming in the Mediterranean

    The Role of Demography in the Transition to Sustainable Societies

    Get PDF
    Currently, although the global population has surpassed 7.5 billion and continues to increase in about 80 million each year, attention to demography is almost absent in most of the studies and publications related to the current situation of planetary emergency and the necessary transition to sustainable societies. For this reason, our first aim in this paper has been to discuss if this current lack of attention to demography is justified or not. With this purpose, we begin considering the scientific meaning of Sustainability, in order to overlay distorted and impoverish views of this concept that may hinder our study. Then, we analyse the reasons given by experts for and against the incidence of demographic growth in the current unsustainable situation of planetary emergency. Finally, we present proposals to face the ensemble of interconnected socio-environmental problems (including demographic evolution), to make possible an appropriate transition to sustainable societies. Aunque la población mundial ha sobrepasado los 7500 millones y continúa aumentando anualmente en alrededor de 80 millones, la atención a la demografía está hoy prácticamente ausente en la mayoría de los estudios y publicaciones acerca de la actual situación de emergencia planetaria y la necesidad de una transición a sociedades sostenibles. Con el propósito de analizar si esta falta de atención a la demografía está o no justificada, en esta contribución comenzamos discutiendo el significado científico de Sostenibilidad socioambiental, para evitar concepciones distorsionadas y empobrecidas de este concepto que pueden dificultar dicho análisis. A continuación estudiaremos las razones dadas por distintos expertos a favor y en contra de la incidencia del crecimiento demográfico en la insostenible situación actual de emergencia planetaria. Finalmente presentamos propuestas para hacer frente al conjunto de problemas estrechamente interconectados - incluido el problema demográfico - que caracterizan dicha situación, para hacer así posible una adecuada transición a sociedades sostenibles

    Visually guided inspiration breath-hold facilitated with nasal high flow therapy in locally advanced lung cancer

    Get PDF
    Background and purpose Reducing breathing motion in radiotherapy (RT) is an attractive strategy to reduce margins and better spare normal tissues. The objective of this prospective study (NCT03729661) was to investigate the feasibility of irradiation of non-small cell lung cancer (NSCLC) with visually guided moderate deep inspiration breath-hold (IBH) using nasal high-flow therapy (NHFT). Material and methods Locally advanced NSCLC patients undergoing photon RT were given NHFT with heated humidified air (flow: 40 L/min with 80% oxygen) through a nasal cannula. IBH was monitored by optical surface tracking (OST) with visual feedback. At a training session, patients had to hold their breath as long as possible, without and with NHFT. For the daily cone beam CT (CBCT) and RT treatment in IBH, patients were instructed to keep their BH as long as it felt comfortable. OST was used to analyze stability and reproducibility of the BH, and CBCT to analyze daily tumor position. Subjective tolerance was measured with a questionnaire at 3 time points. Results Of 10 included patients, 9 were treated with RT. Seven (78%) completed the treatment with NHFT as planned. At the training session, the mean BH length without NHFT was 39 s (range 15-86 s), and with NHFT 78 s (range 29-223 s) (p = .005). NHFT prolonged the BH duration by a mean factor of 2.1 (range 1.1-3.9s). The mean overall stability and reproducibility were within 1 mm. Subjective tolerance was very good with the majority of patients having no or minor discomfort caused by the devices. The mean inter-fraction tumor position variability was 1.8 mm (-1.1-8.1 mm;SD 2.4 mm). Conclusion NHFT for RT treatment of NSCLC in BH is feasible, well tolerated and significantly increases the breath-hold duration. Visually guided BH with OST is stable and reproducible. We therefore consider this an attractive patient-friendly approach to treat lung cancer patients with RT in BH

    Proliferative activity in human breast cancer: Ki-67 automated evaluation and the influence of different Ki-67 equivalent antibodies

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Ki67 labeling index (Ki67 LI), the percentage Ki67 immunoreactive cells, is a measure of tumor proliferation, with important clinical relevance in breast cancer, and it is extremely important to standardize its evaluation.</p> <p>Aim</p> <p>To test the efficacy of computer assisted image analysis (CAIA) applied to completely digitized slides and to assess its feasibility in routine practice and compare the results obtained using two different Ki67 monoclonal antibodies.</p> <p>Materials and methods</p> <p>315 consecutive breast cancer routinely immunostained for Ki-67 (223 with SP6 and 92 with MM1 antibodies previously examined by an experienced pathologist, have been re-evaluated using Aperio Scanscope Xs.</p> <p>Results</p> <p>Mean human Ki67 LI values were 36%± 14.% and 28% ± 18% respectively for SP6 and MM1 antibodies; mean CAM Ki67 LI values were 31%± 19% and 22% ± 18% respectively for SP6 and MM1. Human and CAIA evaluation are statistically highly correlated (Pearson: 0.859, p<0.0001), although human LI are systematically higher. An interobserver variation study on CAIA performed on 84 cases showed that the correlation between the two evaluations was linear to an excellent degree.</p> <p>Discussion</p> <p>Our study shows that a) CAIA can be easily adopted in routine practice, b) human and CAIA Ki67 LI are highly correlated, although human LI are systematically higher, c) Ki67 LI using different evaluation methods and different antibodies shows important differences in cut-off values.</p

    Treatment planning comparison in the PROTECT-trial randomising proton versus photon beam therapy in oesophageal cancer:Results from eight European centres

    Get PDF
    PURPOSE To compare dose distributions and robustness in treatment plans from eight European centres in preparation for the European randomized phase-III PROTECT-trial investigating the effect of proton therapy (PT) versus photon therapy (XT) for oesophageal cancer. MATERIALS AND METHODS All centres optimized one PT and one XT nominal plan using delineated 4DCT scans for four patients receiving 50.4 Gy (RBE) in 28 fractions. Target volume receiving 95% of prescribed dose (V95%iCTVtotal) should be >99%. Robustness towards setup, range, and respiration was evaluated. The plans were recalculated on a surveillance 4DCT (sCT) acquired at fraction ten and robustness evaluation was performed to evaluate the effect of respiration and inter-fractional anatomical changes. RESULTS All PT and XT plans complied with V95%iCTVtotal >99% for the nominal plan and V95%iCTVtotal >97% for all respiratory and robustness scenarios. Lung and heart dose varied considerably between centres for both modalities. The difference in mean lung dose and mean heart dose between each pair of XT and PT plans was in median [range] 4.8 Gy [1.1;7.6] and 8.4 Gy [1.9;24.5], respectively. Patients B and C showed large inter-fractional anatomical changes on sCT. For patient B, the minimum V95%iCTVtotal in the worst-case robustness scenario was 45% and 94% for XT and PT, respectively. For patient C, the minimum V95%iCTVtotal was 57% and 72% for XT and PT, respectively. Patient A and D showed minor inter-fractional changes and the minimum V95%iCTVtotal was >85%. CONCLUSION Large variability in dose to the lungs and heart was observed for both modalities. Inter-fractional anatomical changes led to larger target dose deterioration for XT than PT plans

    Planeamiento territorial sostenible: un reto para el futuro de nuestras sociedades; criterios aplicados

    Get PDF
    In a large part of the 17 sustainable development objectives set as goals for humanity by the UN, sustainability can be glimpsed. As a result of the dominant socio-productive model, the only way to head towards more sustainable territories that allow achieving and maintaining the well-being of the world's population is to bear in mind the need to properly plan territorial development. This work reflects on this need and takes a step forward in the definition of the main criteria to achieve territorial sustainability at regional and local scales
    corecore