320 research outputs found

    Using artificial neural networks to predict impingement and dislocation in total hip arthroplasty

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    Dislocation after total hip arthroplasty (THA) remains a major issue and an important post-surgical complication. Impingement and subsequent dislocation are influenced by the design (head size) and position (anteversion and abduction angles) of the acetabulum and different movements of the patient, with external extension and internal flexion the most critical movements. The aim of this study is to develop a computational tool based on a three-dimensional (3D) parametric finite element (FE) model and an artificial neural network (ANN) to assist clinicians in identifying the optimal prosthesis design and position of the acetabular cup to reduce the probability of impingement and dislocation. A 3D parametric model of a THA was used. The model parameters were the femoral head size and the acetabulum abduction and anteversion angles. Simulations run with this parametric model were used to train an ANN, which predicts the range of movement (ROM) before impingement and dislocation. This study recreates different configurations and obtains absolute errors lower than 5.5° between the ROM obtained from the FE simulations and the ANN predictions. The ROM is also predicted for patients who had already suffered dislocation after THA, and the computational predictions confirm the patient’s dislocations. Summarising, the combination of a 3D parametric FE model of a THA and an ANN is a useful computational tool to predict the ROM allowed for different designs of prosthesis heads

    The potential of drones and sensors to enhance detection of archaeological cropmarks: a comparative study between multi-spectral and thermal imagery

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    Abstract This paper presents experimentation carried out at the Roman Republican city of La Caridad (Teruel, Spain), where different tools have been applied to obtain multispectral and thermal aerial images to enhance detection of archaeological cropmarks. Two different drone systems were used: a Mikrokopter designed by Tecnitop SA (Zaragoza, Spain) and an eBee produced by SenseFly Company (Cheseaux-sur-Lausanne, Switzerland). Thus, in this study, we have combined in-house manufacturing with commercial products. Six drone sensors were tested and compared in terms of their ability to identify buried remains in archaeological settlements by means of visual recognition. The sensors have different spectral ranges and spatial resolutions. This paper compares the images captured with different spectral range sensors to test the potential of this technology for archaeological benefits. The method used for the comparison of the tools has been based on direct visual inspection, as in traditional aerial archaeology. Through interpretation of the resulting data, our aim has been to determine which drones and sensors obtained the best results in the visualization of archaeological cropmarks. The experiment in La Caridad therefore demonstrates the benefit of using drones with different sensors to monitor archaeological cropmarks for a more cost-effective assessment, best spatial resolution and digital recording of buried archaeological remains

    Servidor de datos y página web para el aprendizaje de SIG en la ingeniería forestal

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    Los Sistemas de Información geográfica (SIG) son una herramienta de trabajo habitual en el ámbito de la ingeniería forestal, tanto en la faceta de redacción de proyectos, como en la investigación sobre el medio ambiente y el territorio. Cada vez hay más información cartográfica disponible desde servidores de diferentes instituciones, por lo que consideramos que es muy útil contar con una herramienta de organización de la información. En el trabajo que se presenta, se pretende proporcionar a los estudiantes e investigadores en materia forestal un portal que contenga información actualizada y ordenada sobre los recursos existentes compatibles con los SIG. Por tanto constituiráuna herramienta de apoyo que facilitarála fase de documentación, búsqueda de datos compatibles y aprendizaje de las herramientas que sirven de base para el desarrollo de cualquier trabajo técnico o de investigación relacionado con el medio ambiente y el territorio que se apoye en los SIG

    What scientists contents are presented by political parties and their impact on the scientific literacy of citizenship. Study of the topic "energy"

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    Este trabajo presenta un análisis del contenido científico de los programas electorales. Con este estudio se pretende determinar cuáles son las exigencias cognitivas que este tipo de documentos demandan en la ciudadanía. Para ello, se han analizado los programas de los cuatro partidos de ámbito estatal que consiguieron mayor número de votos en las elecciones generales de 2011. Los resultados muestran que los partidos tratan diversos temas de carácter científico-tecnológico en sus programas. Por otro lado, el análisis de las exigencias cognitivas de un tópico concreto -energía- parece demandar la posesión de ciertos conocimientos elevados de tipo científico, tecnológico, medioambiental y económico. Las conclusiones recogen algunas consideraciones desde la didáctica de las ciencias experimentales respecto a este tipo de contenidos sociocientíficos que tanto afectan a la ciudadanía.This paper presents an analysis of the scientific content of the electoral programs. The aim of this study is to identify the cognitive demands of these documents on the citizenship. In order to do that, we have analysed the programs of the four most voted national parties in the general elections on 2011 [in Spain]. The results show that the parties deal with various topics of scientific and technological nature in their programs. Furthermore, the analysis of the cognitive demands of a particular topic -energy- seems to demand the possession of a high particular knowledge in science, technology, environment and economy. The conclusions indicate some guidance from the teaching of experimental sciences to work this kind of social-scientific content that highly affect citizens

    Gold/ultra-high molecular weight polyethylene nanocomposites for electrical energy storage: Enhanced recovery efficiency upon uniaxial deformation

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    13 pags., 9 figs.The growing demand for renewable energy sources has prompted the development of dielectric materials with the ability to store and efficiently recover electrical energy. Here, we correlate the structure and thermal conductivity of uniaxially oriented disentangled ultra-high molecular weight polyethylene (dis-UHMWPE) composites reinforced with gold nanoparticles with their electrical properties and potential application as electrical energy storage devices. Stretching increases the orientation of the polymer chains and thus the crystallinity and reduces the aggregation of gold nanoparticles while the thermal conductivity enhances significantly along the orientation axis. The structural changes driven by stretching result in two competing effects; on the one hand, the crystallinity increase reduces the permittivity of the composites and increases the resistivity, while on the other hand the recovery efficiency of oriented materials excels that of unstretched samples by up to 6 times at 5 s. Therefore, our work shows the structure–property relationship in electrical energy storage materials.Engineering and Physical Sciences Research Council, Grant/Award Number: EP/K034405/

    Spinodal-assisted crystallization in polymer melts

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    Recent experiments in some polymer melts quenched below the melting temperature have reported spinodal kinetics in small-angle x-ray scattering before the emergence of a crystalline structure. To explain these observations we propose that the coupling between density and chain conformation induces a liquid-liquid binodal within the equilibrium liquid-crystalline solid coexistence region. A simple phenomenological theory is developed to illustrate this idea, and several experimentally testable consequences are discussed. Shear is shown to enhance the kinetic role of the hidden binodal

    Manejo expectante de gestación ectópica abdominal tras fecundación in vitro en paciente con salpinguectomía bilateral. Reporte de un caso

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    ANTECEDENTES El embarazo ectópico abdominal es el menos habitual de los embarazos ectópicos, con una prevalencia situada entre el 0.9 - 1.4%. La mortalidad materna es elevada, alcanzando un 20% y la viabilidad fetal mínima. El manejo médico en estas situaciones es complicado ya que no está bien establecido debido a su baja frecuencia. CASO CLÍNICO Mujer de 35 años, con antecedente de esterilidad por endometriosis y salpinguectomía bilateral. Tras 5 fecundaciones in vitro (FIV) consigue una primera gestación, con finalización mediante cesárea por no progresión de parto. Acude a urgencias en su segundo embarazo, logrado tras 3 (FIV), con edad gestacional de 7 semanas. Presenta sangrado vaginal escaso y la ecografía demuestra a nivel de Douglas y hacia fosa iliaca izquierda un saco gestacional de 3 cm con embrión sin latido cardiaco de 5 mm. El nivel de ß-hcg es de 1477 mUI/ml. Se diagnostica de gestación ectópica abdominal y se opta por actitud expectante dada la estabilidad clínica de la paciente. En un control a las 48h la ß-Hcg es de 464 mUI/ml y la paciente se mantiene estable. En controles posteriores se observan niveles descendentes de ß-Hcg y tras un mes la resolución es completa. CONCLUSIÓN El embarazo ectópico abdominal es una entidad poco frecuente pero con una alta tasa de mortalidad. Aunque lo más común es optar por un abordaje quirúrgico es necesario individualizar cada caso y basarse en la clínica y las diferentes pruebas diagnósticas para seleccionar aquellos casos que se pueden beneficiar de un manejo conservador. BACKGROUND Abdominal ectopic pregnancy accounts for only 0.9-1.4% of all ectopic pregnancies. The maternal mortality rate is high (up to 20%) and fetal viability mínimum. The managment, specially the conservatory management of these cases is difficult because of our limited experiencie due to its low frecuency. CASE PRESENTATION 35-year-old woman, with history of sterility due to endometriosis that required bilateral laparoscopic salpinguectomy. Her first pregnancy (after 5 in vitro fertilization cicles (IVF)) finalized with a caesarean section because of to the lack of labour progresion. She was admitted to our emergency department during her second pregnancy (after 3 IVF cicles), with 7 weeks of gestational age. She had a little vaginal bleeding. Ultrasound scan showed a 5mm gestational sac with a 3mm embryo without cardiac activity in the pouch of Douglas. The ß-Hcg level was 1477mUI/ml. The final diagnosis was ectopic abdominal pregnancy and it was decided to undertake an expectant management because she was clinically stable. The ß-Hcg level after 48 hours was 464 mUI/ml. In subsequent examinations ß-Hcg showed descending levels and after one month the resolution was completed. CONCLUSION Abdominal ectopic pregnancy is very infrequent but it has a high mortality rate. The most common approach is surgical but it is necessary to study all signs and diagnostic tests to select patients that could get profit from a conservatory management

    Unemployment benefits : discursive convergence, distant realities

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    Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004Unemployment protection systems have certain characteristics in common in Argentina, Uruguay, Spain and Italy: they are compulsory and contributory-proportional, although in Uruguay, it also has a capitalisation supplement. Despite the similarities, they work differently because the context of informal employment chiefly, and unemployment, low salaries and precariousness differ greatly. Consequently, the unemployment protection coverage rate varies. Theories of the Active Welfare State, the Investor State and the reforms of unemployment protection systems have led to a certain modernising language being adopted in these countries: activation, employability, conditionality, lifelong learning, flexibility, which are, among others, words shared with Europe. However, the meanings of these words differ according to the institutional context of each country. In Latin America the welfare state is low institutionalised even almost non-existent, while in Europe it is a diverse institution. Despite this, the four countries share an upward trend in benefit policies, in accordance with the increase in poverty risk

    Quantitative trait locus analysis identifies Gabra3 as a regulator of behavioral despair in mice

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    The Tail Suspension Test (TST), which measures behavioral despair, is widely used as an animal model of human depressive disorders and antidepressant efficacy. In order to identify novel genes involved in the regulation of TST performance, we crossed an inbred strain exhibiting low immobility in the TST (RIIIS/J) with two high-immobility strains (C57BL/6J and NZB/BlNJ) to create two distinct F2 hybrid populations. All F2 offspring (n = 655) were genotyped at high density with a panel of SNP markers. Whole-genome interval mapping of the F2 populations identified statistically significant quantitative trait loci (QTLs) on mouse chromosomes (MMU) 4, 6, and X. Microarray analysis of hippocampal gene expression in the three parental strains was used to identify potential candidate genes within the MMUX QTLs identified in the NZB/BlNJ × RIIIS/J cross. Expression of Gabra3, which encodes the GABAA receptor α3 subunit, was robust in the hippocampus of B6 and RIIIS mice but absent from NZB hippocampal tissue. To verify the role of Gabra3 in regulating TST behavior in vivo, mice were treated with SB-205384, a positive modulator of the α3 subunit. SB-205384 significantly reduced TST immobility in B6 mice without affecting general activity, but it had no effect on behavior in NZB mice. This work suggests that GABRA3 regulates a behavioral endophenotype of depression and establishes this gene as a viable new target for the study and treatment of human depression
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