1,710 research outputs found

    Cambios ontogenéticos e intraespecíficos observados en la rádula de Polycera aurantiomarginata García and Bobo, 1984 (Gastropoda Opisthobranchia)

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    Polycera aurantiomarginata García and Bobo 1984 has a stable population in the intertidal area of El Portil beach (Huelva, SW Spain). This fact allowed specimens of different sizes to be collected from March 2001 to December 2003. In this paper, the ontogenetic variations of the radula of P. aurantiomarginata are studied. The radulae of 141 specimens were examined, 138 from El Portil and 3 from La Herradura (Granada, SE Spain). Specimens of 1.5-2 mm in length lack the typical radula described for P. aurantiomarginata. They have the so called pre-radula whose teeth are different in size and shape from the typical radula of the adults. In the specimens of 3 and 4 mm the pre-radula coexists with the characteristic radula, which is the single structure present in the specimens larger than 4 mm. The following features of the radula are included in this study: radular length, number of teeth rows and length of the outer lateral teeth. According to the three measured variables, the affinities among specimens without a pre-radula were established through cluster analysis, which defined three different groups (4-10 mm, 11-22 mm and 23-48 mm). Correlations between specimen length and radula length, number of rows and mean length of outer lateral teeth were significant. Feeding strategies could be related to the different morphology of the radula established by the Cluster analysis.Polycera aurantiomarginata García y Bobo, 1984 muestra una población estable y en la localidad de El Portil (Huelva, SW de España), lo que ha permitido la recolección, desde marzo de 2001 hasta diciembre de 2003, de un alto número de ejemplares de todos los tamaños. En el presente estudio se ha extraído la rádula de 141 animales, 138 recogidos en la zona intermareal de El Portil y 3 en La Herradura (Granada). Los tamaños de los animales han oscilado entre 1.5 mm y 48 mm. Se ha podido observar en los individuos de entre 1.5 y 2 mm la existencia de una pre-rádula cuyos dientes son morfológicamente diferentes a los de la rádula de los individuos mayores; sin embargo, en los ejemplares de 3 y 4 mm esta pre-rádula coexiste con la rádula típica, siendo esta estructura la única presente en individuos de longitud igual o mayor a 4 mm. A cada una de las rádulas extraídas, tanto con pre-rádula o sin ella, se le ha medido la longitud total de la cinta, la longitud del diente lateral externo y el número de filas de dientes. Considerando los tres parámetros medidos, las afinidades entre los ejemplares sin pre-rádula se establecieron a partir de análisis de Cluster, que definieron tres grupos distintos (4-10 mm, 11-22 mm y 23-48 mm). Las correlaciones existentes entre la longitud de los individuos y la longitud de la rádula, el número de filas y la longitud media de los dientes fueron significativas. Las diferencias morfológicas reconocidas en los grupos considerados podrían estar relacionadas con distintas estrategias alimentarias.

    Influence of available resources on medical practitioners’ decision-making process and practice: study of a reference hospital emergency department

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    Objetivo: Evaluar la variación del indicador “periodo de tiempo de observación” dedicado a cada paciente, en respuesta a una reducción del número de camas disponibles. Métodos: Se realizó un estudio «quasiexperimental preprueba postprueba» sin grupo control en una unidad de urgencias durante 2 períodos de un mes. En este tiempo el único cambio fue el número de camas disponibles, que disminuyeron de 20 (período A) a 16 (período B). Resultados: El servicio de urgencias atendió a 7.725 pacientes: 3.706 pacientes en el período A, 335 de los cuales fueron admitidos en la unidad de observación con una estancia media de 1.105,4 minutos por paciente; y 4.019 pacientes en el período B, 570 de los cuales fueron admitidos en la unidad de observación con una estancia media de 686,1 minutos por paciente (p < 0,001). No hubo variaciones en la mortalidad, readmisiones o quejas. Conclusiones: Una disminución en el número de camas disponibles para observación comporta una reducción en el tiempo de estancia de los pacientes

    Monitoring Coxiella burnetii Infection in Naturally Infected Dairy Sheep Flocks Throughout Four Lambing Seasons and Investigation of Viable Bacteria.

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    Progression of Coxiella burnetii infection in four naturally infected sheep flocks, and in their farm environment, was monitored throughout four lambing seasons. Flocks with an active infection were selected based on the presence of C. burnetii DNA in bulk-tank milk (BTM) and a high seroprevalence in yearlings during the previous milking period (Spring 2015). During four consecutive lambing seasons (2015/16-2018/19), samples were collected within 1 week after each lambing period from animals (vaginal swabs, milk and feces from ewes, and yearlings) and the environment (dust indoor sheep premises). BTM samples and aerosols (outdoors and indoors) were monthly collected between lambing and the end of milking. Real-time PCR analyses showed different trends in C. burnetii shedding in the flocks, with a general progressive decrease in bacterial shedding throughout the years, interrupted in three flocks by peaks of reinfection associated with specific management practices. A significant relationship was found between C. burnetii fecal shedding and the bacterial burden detected in dust, whereas shedding by vaginal route affected the detection of C. burnetii in indoor aerosols. Three genotypes were identified: SNP8 (three flocks, 52.9% of the samples), SNP1 (two flocks, 44.8% samples), and SNP5 (one flock, two environmental samples). Coxiella burnetii viability in dust measured by culture in Vero cells was demonstrated in two of the flocks, even during the fourth lambing season. The results showed that infection can remain active for over 5 years if effective control and biosafety measures are not correctly implemented.This work was funded by INIA—Spanish National Institute for Agricultural and Food Research and Technology (RTA2017-00055-C02-00), the European Regional Development Funds (ERDF), and the Basque Government. RÁ-A is beneficiary of a Ph.D. contract funded by INIA (FPI-2015-014). The funders had no role in the study design, data collection and interpretation, or the decision to submit the work for publication.S

    Impacto del rendimiento académico de primer semestre en el abandono de primer año

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    El objetivo de este trabajo es presentar una propuesta sostenible para el seguimiento y evaluación sistemática del abandono de primer curso en titulaciones relacionadas con la Ingeniería Informática, basada en el tratamiento automático de la información disponible en la universidad. En trabajos previos se ha desarrollado una aplicación informática online, ASIA1a (Aplicación para el Seguimiento Institucional del Abandono de primer año). Usando esta aplicación, se puede analizar el impacto sobre el abandono de diferentes variables. En particular, se ha constatado que uno de los mejores predictores del abandono es el rendimiento académico de primer año. Pero esta variable se conoce demasiado tarde para poder adoptar medidas preventivas. El estudio presentado ahora demuestra que se puede predecir el abandono de primer año a partir de los resultados académicos de las asignaturas de primer semestre, con la ventaja de que esta información se conoce antes. Se concluye que es posible, mediante el tratamiento automático de la información, hacer un seguimiento del proceso de integración de los estudiantes de primer año, evaluar la eficacia de los programas de acogida e identificar alumnos en riesgo de abandono, con el fin de proponer acciones específicas.The goal in this work is to present a sustainable proposal to assess first-year drop-out, in Computer Engineering degrees, based on the systems for automatic treatment of information. An online computer application, ASIA1a (Aplicación para el Seguimiento Institucional del Abandono de primer año), was previously developed, and it has been used to analyze the impact of several different variables on the first-year drop-out rate. It has been observed, in particular, that one of the best predictors of drop-out is academic performance throughout the first year. Unfortunately, this information gets to be known too late to be able to take remedial actions. The present study shows that first-year drop-out can be reliably predicted using only the academic results of courses in the first semester, which are known much earlier. One may thus conclude that it is possible to keep track of the integration process of first-year students by using the automatic means of treatment of the information available on them, thus evaluating the efficiency of the welcoming programs, and identifying the students most likely to drop out in order to propose measures to avoid it

    Magnetic anisotropy of maghemite nanoparticles probed by RF transverse susceptibility

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    We present radio frequency magnetic transverse susceptibility measurements on γ-Fe2O3 nanoparticles, which yield an estimation of their effective anisotropy constant, Keff as a function of nanoparticle size. The resulting values range from 4 to 8 × 104 erg/cm3, being on the order of the magnetocrystalline anisotropy in bulk maghemite. Keff values increase as the particle diameter increases. Evidences of anisotropy field distribution given by the size distribution in the samples, and interparticle interactions that increase as the particle size increases, are also observed in the TS measurements. The effects of such interparticle interaction overcome those of thermal fluctuations, in contrast with the behavior of other iron oxide particles.The financial support of the Spanish MINECO MAT2011-23791, MAT2014-53921-R, and MAT2014-54975-R and Aragonese DGA-IMANA E34 and M4 projects is acknowledged.Peer Reviewe

    Discriminant analysis using fatty acids profile, stable carbon isotopes and tocopherols content as tool for feeding system prediction in Iberian pigs

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    Aim of study: The application of three analytical methods (fatty acids: FA, tocopherols: TOC, and isotope ratio: ISO) to distinguish the feeding type received by Iberian pigs during the fattening stage.Area of study: This distinction is very important for the labelling of Iberian high-quality products in the Quercus forest located on the southwest of Iberian Peninsula, where several production systems coexist.Material and methods: Discriminant analysis on fat samples with unknown background obtained from commercial pigs was applied. The feasibility of the combination method to determine the authentication of feeding background was studied on samples from different fattening system: free-range feeding with acorn and pastures (BE); free-range feeding acorn and pastures plus commercial feeds (RE); open-air feeding with commercial feeds (CA); standard feeding with commercial feeds (CE).Main results: In a first application of the methods, the overall success rate was 60.1% for FA, 49.7% for ISO and 49.3% for TOC. When some of the batches were reclassified attending to those previous results and additional information available about farm characteristics, ISO and TOC analyses had a 70% of success rate in the four categories, whereas FA showed 40.5%, attributable to the use of high-oleic commercial diets. The predictions improved with the method combination. The ISO+TOC combination achieved a 84.1% of success in prediction. When it was reduced to just two categories (acorn vs non-acorn), the success reached a 95% for FA+TOC and ISO+TOC.Research highlights: The use of these methods as a complementary tool for quality controls is highly recommended to avoid undesirable misclassifications

    Somatic and germline analysis of a familial Rothmund-Thomson syndrome in two siblings with osteosarcoma

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    Rothmund–Thomson syndrome (RTS) is characterized by a rash that begins in the first few months of life and eventually develops into poikiloderma. Associated symptoms are alterations in the teeth, sparse hair, thin eyebrows, lack of eyelashes, low stature, bone abnormalities, hematological illnesses, gastrointestinal disease, malnutrition, cataracts, and predisposition to cancer, principally to bone tumors and skin cancer. Diagnostic certitude is provided by a genetic study involving detection of pathogenic variants of the RECQL4 gene. We hereby present a familiar case of RTS in two siblings from a Portuguese family, both diagnosed with osteosarcoma. Genomic analysis (203 genes) of both tumors as well as germline analysis of the RECQL4 gene, thus confirming the syndrome in the family, have been performed. The relevance of clinical recognition of the hallmarks of the disease and thus early diagnosis with early intervention is highlighted

    Land-use change and windstorms legacies drove the recolonization dynamics of laurel forests in Tenerife, Canary islands

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    Laurel forests are quite relevant for biodiversity conservation and are among the island ecosystems most severely damaged by human activities. In the past, Canary laurel forests have been greatly altered by logging, livestock and agriculture. The remains of laurel forests are currently protected in the Canary Islands (Spain). However, we miss basic information needed for their restoration and adaptive management, such as tree longevity, growth potential and responsiveness to natural and anthropogenic disturbances. Using dendrochronological methods, we studied how forest dynamic is related to land-use change and windstorms in two well-preserved laurel forests on Tenerife Island. Wood cores were collected from over 80 trees per stand at three stands per forest. We used ring-width series to estimate tree ages and calculate annual basal area increments (BAI), cumulative diameter increases, and changes indicative of released and suppressed growth. Twelve tree species were found in all stands, with Laurus novocanariensis, Ilex canariensis and Morella faya being the most common species. Although some individuals were over 100 years old, 61.8%–88.9% of the trees per stand established between 1940 and 1970, coinciding with a post-war period of land abandonment, rural exodus and the onset of a tourism economy. Some trees have shown growth rates larger than 1 ​cm diameter per year and most species have had increasing BAI trends over the past decades. Strong growth releases occurred after windstorms at both sites, but the effects of windstorms were site-dependent, with the 1958 storm affecting mainly the eastern tip of the island (Anaga massif) and the 1991 storm the western tip (Teno massif). Given the great ability of laurel forest trees to establish after land use cessation and to increase growth after local disturbances such as windstorms, passive restoration may be sufficient to regenerate this habitat in currently degraded areas.12 página
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