60 research outputs found

    Latitudinal environmental niches and riverine barriers shaped the phylogeography of the Central Chilean endemic Dioscorea humilis (Dioscoreaceae)

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    The effects of Pleistocene glaciations and geographical barriers on the phylogeographic patterns of lowland plant species in Mediterranean-climate areas of Central Chile are poorly understood. We used Dioscorea humilis (Dioscoreaceae), a dioecious geophyte extending 530 km from the Valparaíso to the Bío-Bío Regions, as a case study to disentangle the spatio-temporal evolution of populations in conjunction with latitudinal environmental changes since the Last Inter-Glacial (LIG) to the present. We used nuclear microsatellite loci, chloroplast (cpDNA) sequences and environmental niche modelling (ENM) to construct current and past scenarios from bioclimatic and geographical variables and to infer the evolutionary history of the taxa. We found strong genetic differentiation at nuclear microsatellite loci between the two subspecies of D. humilis, probably predating the LIG. Bayesian analyses of population structure revealed strong genetic differentiation of the widespread D. humilis subsp. humilis into northern and southern population groups, separated by the Maipo river. ENM revealed that the ecological niche differentiation of both groups have been maintained up to present times although their respective geographical distributions apparently fluctuated in concert with the climatic oscillations of the Last Glacial Maximum (LGM) and the Holocene. Genetic data revealed signatures of eastern and western postglacial expansion of the northern populations from the central Chilean depression, whereas the southern ones experienced a rapid southward expansion after the LGM. This study describes the complex evolutionary histories of lowland Mediterranean Chilean plants mediated by the summed effects of spatial isolation caused by riverine geographical barriers and the climatic changes of the Quaternary. Copyright: © 2014 Bischoff et al.Financial support for this study was provided by a Fundación BBVA BIOCON 05-093/06 project grant to PC and JGSM. JV was supported by a Fundación BBVA Ph.D. grant. JGSM was supported by two consecutive Spanish Aragón Government ‘‘Araid’’ and Spanish Ministry of Science and Innovation ‘‘Ramón y Cajal’’ postdoctoral contracts. PC was partially funded by a Bioflora (http://bifi.es/bioflora/) research team grant co-funded by the Spanish Aragón Government and the European Social Fund.Peer Reviewe

    Limitations of Grundy and Kabaila s Simplified Method and Its Repercussion on the Safety and Serviceability of Successively Shored Building Structures

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    [EN] One of the most critical stages for a structure s safety is its construction process, and this problem is even more acute in buildings with reinforced concrete structures. These structures are usually built by shoring successive floors, so that the most recently poured floor rests on the lower floors by means of shores. It is therefore vitally important to have calculation tools available to estimate the loads to which the shores and slabs will be subjected in each stage of construction. A number of calculation methods have been proposed to date, of which the one proposed by Grundy and Kabaila in 1963 is the best known and most frequently used. This paper analyzes the limitations of Grundy and Kabaila s method by means of a parametric study of finite-element method simulations that identified a large number of situations in which this method presented unsafe results in terms of the estimated loads on slabs. In many situations, therefore, applying this method could gravely affect a building s in-service behavior and durability. The paper s final objectives are to make the reader aware of the limitations of Grundy and Kabaila s method and the need to use the more refined methods that are now available to estimate the loads on shores and slabs in reinforced concrete buildings under constructionThe authors would like to express their gratitude to the Spanish Ministry of Education, Culture and Sport for funding received under the FPU Program (FPU13/02466) and to the Generalitat Valenciana (GV/2015/063).Adam Martínez, JM.; Buitrago Moreno, M.; Moragues Terrades, JJ.; Calderón García, PA. (2017). Limitations of Grundy and Kabaila s Simplified Method and Its Repercussion on the Safety and Serviceability of Successively Shored Building Structures. Journal of Performance of Constructed Facilities. 31(5):1-2. doi:10.1061/(ASCE)CF.1943-5509.0001038S1231

    Diagnosis of invasive candidiasis by enzyme-linked immunosorbent assay using the N-terminal fragment of Candida albicans hyphal wall protein 1

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    <p>Abstract</p> <p>Background</p> <p>The diagnosis of invasive candidiasis is difficult because there are no specific clinical manifestations of the disease and colonization and infection are difficult to distinguish. In the last decade, much effort has been made to develop reliable tests for rapid diagnosis of invasive candidiasis, but none of them have found widespread clinical use.</p> <p>Results</p> <p>Antibodies against a recombinant N-terminal fragment of the <it>Candida albicans </it>germ tube-specific antigen hyphal wall protein 1 (Hwp1) generated in <it>Escherichia coli </it>were detected by both immunoblotting and ELISA tests in a group of 36 hematological or Intensive Care Unit patients with invasive candidiasis and in a group of 45 control patients at high risk for the mycosis who did not have clinical or microbiological data to document invasive candidiasis. Results were compared with an immunofluorescence test to detect antibodies to <it>C. albicans </it>germ tubes (CAGT). The sensitivity, specificity, positive and negative predictive values of a diagnostic test based on the detection of antibodies against the N-terminal fragment of Hwp1 by immunoblotting were 27.8 %, 95.6 %, 83.3 % and 62.3 %, respectively. Detection of antibodies to the N-terminal fragment of Hwp1 by ELISA increased the sensitivity (88.9 %) and the negative predictive value (90.2 %) but slightly decreased the specificity (82.6 %) and positive predictive values (80 %). The kinetics of antibody response to the N-terminal fragment of Hwp1 by ELISA was very similar to that observed by detecting antibodies to CAGT.</p> <p>Conclusion</p> <p>An ELISA test to detect antibodies against a recombinant N-terminal fragment of the <it>C. albicans </it>germ tube cell wall antigen Hwp1 allows the diagnosis of invasive candidiasis with similar results to those obtained by detecting antibodies to CAGT but without the need of treating the sera to adsorb the antibodies against the cell wall surface of the blastospore.</p

    Improving construction processes of concrete building structures using load limiters on shores

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    This paper analyses the redistribution of maximum loads using a system of load limiters on shores in which the limiters yield at a given load and thus reduce the maximum load absorbed by the shores. For this analysis a finite element modelling (FEM) of an experimental building was developed in which load limiters had been fitted to the shores to restrict their maximum load to a given value. This was designed to: (a) optimise slab construction costs by using shores of lower load-bearing capacities, (b) improve safety during the construction of consecutive concrete slab floors by reducing maximum loads and redistributing loads amongst the shores; and (c) increase structural efficiency by more efficient use of the materials employed due to load redistribution. It has been estimated that using load limiters in this way can reduce total shoring costs in a building project by between 30% and 40%.The authors would like to express their gratitude to the Universitat Politecnica de Valencia for funding this research project (PAID-06-11) and also to the Encofrados J. Alsina Company for their invaluable cooperation.Buitrago Moreno, M.; Alvarado Vargas, YA.; Adam Martínez, JM.; Calderón García, PA.; Gasch, I.; Moragues, JJ. (2015). Improving construction processes of concrete building structures using load limiters on shores. Engineering Structures. 100:104-115. doi:10.1016/j.engstruct.2015.06.007S10411510

    Phonological and semantic verbal fluency test: Scoring criteria and normative data for clustering and switching strategies for Colombian children and adolescents

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    Background: Verbal fluency tests (VFT) are highly sensitive to cognitive deficits. Usually, the score on VFT is based on the number of correct words produced, yet it alone gives little information regarding underlying test performance. The implementation of different strategies (cluster and switching) to perform effi-ciently during the tasks provide more valuable information. However, normative data for clustering and switching strategies are scarce. Moreover, scoring criteria adapted to Colombian Spanish are missing. Aims: (1) To describe the Colombian adaptation of the scoring system guidelines for clustering and switching strategies in VFT; (2) to determine its reliability; and (3) to provide normative data for Colombian children and adolescents aged 6–17 years. Methods & Procedures: A total of 691 children and adolescents from Colombia completed phonological (/f/, /a/, /s/, /m/, /r/ and /p/) and semantic (animals and fruits) VFT, and five scores were calculated: total score (TS), number of clusters (NC), cluster size (CS), mean cluster size (MCS) and number of switches (NS). The intraclass correlation coefficient was used for interrater reliability. Hierarhical multiple regressions were conducted to investigate which strategies were associated with VFT TS. Multiple regressions were conducted for each strategy, including as predictors age, age2, sex, mean parents’ education (MPE), MPE2 and type of school, to generate normative data. Outcomes & Results: Reliability indexes were excellent. Age was associated with VFT TS, but weakly compared with strategies. For both VFT TS, NS was the strongest variable, followed by CS and NC. Regarding norms, age was the strongest predictor for all measures, while age2 was relevant for NC (/f/phoneme) and NS (/m/ phoneme). Participants with higher MPE obtained more NC, and NS, and larger CS in several phonemes and categories. Children and adolescents from private school generated more NC, NS and larger CS in /s/phoneme. Conclusions & Implications: This study provides new scoring guidelines and normative data for clustering and switching strategies for Colombian children and adolescents between 6 and 17 years old. Clinical neuropsychologists should include these measures as part of their everyday practice.Open access funding provided by Universidad Pública de Navarra

    Application of structured light system technique for authentication of wooden panel paintings

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    [EN] This paper presents a new application of photogrammetric techniques for protecting cultural heritage. The accuracy of the method and the fact that it can be used to carry out different tests without contact between the sample and the instruments can make this technique very useful for authenticating and cataloging artworks. The application focuses on the field of pictorial artworks, and wooden panel paintings in particular. In these works, the orography formed by the brushstrokes can be easily digitalized using a photogrammetric technique, called Structured Light System, with submillimeter accuracy. Thus, some of the physical characteristics of the brushstrokes, like minimum and maximum heights or slopes become a fingerprint of the painting. We explain in detail the general principles of the Structured Light System Technique and the specific characteristics of the commercial set-up used in this work. Some experiments are carried out on a sample painted by us to check the accuracy limits of the technique and to propose some tests that can help to stablish a methodology for authentication purposes. Finally, some preliminary results obtained on a real pictorial artwork are presented, providing geometrical information of its metric features as an example of the possibilities of this applicationThis work was financially supported by Generalitat Valenciana through Contract No. AICO/2015/005.Buchón Moragues, FF.; Bravo, JM.; Ferri García, M.; Redondo, J.; Sánchez Pérez, JV. (2016). Application of structured light system technique for authentication of wooden panel paintings. Sensors. 16(881):1-10. https://doi.org/10.3390/s16060881S1101688

    Análisis de la situación de los estudios agronómicos y forestales en Europa. Anexo III: análisis de los estudios europeos

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    El documento que se presenta es el resultado del análisis de la situación actual en estas ingenierías y del estudio del futuro de las mismas. Todas las propuestas que aquí se hacen se han consensuado en las sesiones del Plenario del grupo de trabajo. Por ello, es justo reconocer la aportación que este trabajo puede suponer a la futura Convergencia Europea en la Educación Superior

    Adiciones y correcciones a la orquidoflora valenciana, VII

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    Se aportan datos sobre algunos táxones de Orchidaceae que resultan escasos en la Comunidad Valenciana o en determinadas de sus comarcas; a destacar la presencia de Ophrys santonica y O. × pseudospeculum en Alicante.It is shown some data about rare taxa of Orchidaceae at the Valencian Community (E Spain) or expansions of area to new shires; to emphasize the presence of Ophrys santonica and O. × pseudospeculum in Alicante

    Zinc-Doped Iron Oxide Nanoparticles as a Proton-Activatable Agent for Dose Range Verification in Proton Therapy

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    Proton therapy allows the treatment of specific areas and avoids the surrounding tissues. However, this technique has uncertainties in terms of the distal dose fall-off. A promising approach to studying the proton range is the use of nanoparticles as proton-activatable agents that produce detectable signals. For this, we developed an iron oxide nanoparticle doped with Zn (IONP@Zn-cit) with a hydrodynamic size of 10 nm and stability in serum. Cytotoxicity, defined as half of the surveillance, was 100 &mu;g Zn/mL in the U251 cell line. The effect on clonogenic cell death was tested after X-ray irradiation, which suggested a radioprotective effect of these nanoparticles at low concentrations (1&ndash;10 &mu;g Zn/mL). To evaluate the production of positron emitters and prompt-gamma signals, IONP@Zn-cit was irradiated with protons, obtaining prompt-gamma signals at the lowest measured concentration (10 mg Zn/mL). Finally, 67Ga-IONP@Zn-cit showed accumulation in the liver and spleen and an accumulation in the tumor tissue of 0.95% ID/g in a mouse model of U251 cells. These results suggest the possibility of using Zn nanoparticles as proton-activatable agents to verify the range by prompt gamma detection and face the challenges of prompt gamma detection in a specific biological situation, opening different avenues to go forward in this field
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