Broadband transverse susceptibility in multiferroic Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22

Producción CientíficaNoncollinear spin systems with magnetically induced ferroelectricity from changes in spiral magnetic ordering have attracted significant interest in recent research due to their remarkable magnetoelectric effects with promising applications. Single phase multiferroics are of great interest for these new multifunctional devices, being Y-type hexaferrites good candidates, and among them the ZnY compounds due to their ordered magnetic behaviour over room temperature. Polycrystalline Y type hexaferrites with composition Ba0.5Sr1.5Zn2Fe2O22 (BSZFO) were sintered in 1050 °C–1250 °C temperature range. Transverse susceptibility measurements carried out on these BSZFO samples in the temperature range 80–350 K with DC fields up to ± 5000 Oe reveal different behaviour depending on the sintering temperature. Sample sintered at 1250 °C is qualitatively different, suggesting a mixed Y and Z phase like CoY hexaferrites. Sintering at lower temperatures produce single phase Y-type, but the transverse susceptibility behaviour of the sample sintered at 1150 °C is shifted at temperatures 15 K higher. Regarding the DC field sweeps the observed behaviour is a peak that shifts to lower values with increasing temperature, and the samples corresponding to single Y phase exhibit several maxima and minima in the 250 K–330 K range at low DC applied field as a result of the magnetic field induced spin transitions in this compound.Ministerio de Ciencia, Innovación y Universidades; Agencia Estatal de Investigación with FEDER (MAT2016-80784-P

Android Malware Characterization using Metadata and Machine Learning Techniques

Android Malware has emerged as a consequence of the increasing popularity of smartphones and tablets. While most previous work focuses on inherent characteristics of Android apps to detect malware, this study analyses indirect features and meta-data to identify patterns in malware applications. Our experiments show that: (1) the permissions used by an application offer only moderate performance results; (2) other features publicly available at Android Markets are more relevant in detecting malware, such as the application developer and certificate issuer, and (3) compact and efficient classifiers can be constructed for the early detection of malware applications prior to code inspection or sandboxing.Comment: 4 figures, 2 tables and 8 page

Erosión minera en la cuenca del arroyo Peñalén (Parque Natural del Alto Tajo, Guadalajara)

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Affective Variables in Second Language Acquisition and their Effect on the Spanish Academic Context

For many students, learning a Second Language (SL) can either be a rewarding or a threatening experience. Recent studies claim that this is caused by the role that the affective domain plays in the learning process. Since the affective variables are considered the least understood by researchers in Second Language Acquisition (SLA), this paper focuses on them. The main purpose in this research is to study the connection among anxiety, attitude and motivation and their effect on the academic performance of sixty-six Spanish students who are learning English as a SL. Teachers are also observed to know to what extent they alter those students’ attitudes, feelings of anxiety and motivation towards their language classes.  Since the students who take part in this research share the same teacher, other two teachers are observed in order to analyze whether they have the same effect on their students or not. Results point out that there are clear contrasts between bilingual and non bilingual students and the different performances of the three teachers who were observed.DOI: 10.20420/rlfe.2015.000

Software tools for conducting bibliometric analysis in science: An up-to-date review

Bibliometrics has become an essential tool for assessing and analyzing the output of scientists, cooperation between universities, the effect of state-owned science funding on national research and development performance and educational efficiency, among other applications. Therefore, professionals and scientists need a range of theoretical and practical tools to measure experimental data. This review aims to provide an up-to-date review of the various tools available for conducting bibliometric and scientometric analyses, including the sources of data acquisition, performance analysis and visualization tools. The included tools were divided into three categories: general bibliometric and performance analysis, science mapping analysis, and libraries; a description of all of them is provided. A comparative analysis of the database sources support, pre-processing capabilities, analysis and visualization options were also provided in order to facilitate its understanding. Although there are numerous bibliometric databases to obtain data for bibliometric and scientometric analysis, they have been developed for a different purpose. The number of exportable records is between 500 and 50,000 and the coverage of the different science fields is unequal in each database. Concerning the analyzed tools, Bibliometrix contains the more extensive set of techniques and suitable for practitioners through Biblioshiny. VOSviewer has a fantastic visualization and is capable of loading and exporting information from many sources. SciMAT is the tool with a powerful pre-processing and export capability. In views of the variability of features, the users need to decide the desired analysis output and chose the option that better fits into their aims

Analysis and proposal of intervention in a case of pregnancy delusion

Introducción: Se presenta el caso de una mujer con diagnóstico de esquizofrenia paranoide. Mantiene la creencia delirante de estar embarazada a pesar de la certeza y evidencia de lo contrario. Ha rechazado el tratamiento farmacológico así como realizarse determinadas pruebas médicas necesarias para la mejora de su salud por miedo a dañar al feto. Por motivos de accesibilidad para intervenir con la paciente, se presenta una evaluación exhaustiva junto al planteamiento de los objetivos de tratamiento, siendo este último diseñado de forma hipotética sin que haya sido posible su aplicación. Método: Se han utilizado diferentes fuentes de información, principalmente, la entrevista clínica y varios instrumentos sobre sintomatología positiva y ajuste psicosocial. Se sugiere como hipótesis explicativa de esta convicción delirante de embarazo, la interpretación errónea de experiencias perceptivas anómalas (amenorrea, náuseas, mareos, distensión abdominal…). Resultados: La focalización de la atención únicamente a las experiencias sobre el estado físico, debido al deseo de ser madre, junto a este sesgo en la interpretación estaría reforzando la propia ideación delirante de embarazo al convertirse en la única alternativa para explicar tal complejidad. No se aplicó la intervención propuesta debido al abandono del tratamiento. Discusión: Para una mejor comprensión de este tipo de problemática, en cuanto a su naturaleza y factores implicados así como para el diseño de intervenciones psicológicas eficaces, se insiste en la importancia de realizar un mayor número de investigacionesIntroduction: The case of a woman with paranoid schizophrenia diagnosis is presented. She showed the delusional belief of being pregnant, conception that faithfully remains despite of the certainty and evidence of the opposite. She has denied drug treatment and medical tests needed to improve their health made for fear of damaging the fetus. Due to receptiveness reasons to interact with the patient, a thorough examination is made along with the treatment objectives, being this last one designed hypothetically because its application has never been possible. Method: Many different information sources has been used, mainly the clinical interview and few instruments related to positive symptomatology and psychosocial adjustment. As an explanatory hypothesis suggested for the delusional conviction of being pregnant, the wrong interpretation of abnormal perceptive experiences (amenorrhea, nauseas, dizziness, abdominal distension…). Results: To focus the attention uniquely on the experiences of the physical condition, due to the desire of being a mother, along with this bias on the interpretation would be reinforcing its own delusional conception of pregnancy becoming the only alternative to explain such a complexity. Did not apply the proposed intervention due to the abandonment of treatment. Discussion: For a better comprehension of this problematic type, regarding to its nature and implied factors as well as for the design of effective psychological interventions, it insists on the importance of carry out a greater number of researches