Investigation on the structural and magnetic properties of sputtered TbFe2/Fe3Ga heterostructures

We have analyzed the structural and magnetic properties of as-grown and annealed [TbFe2/Fe3Ga]n heterostructures grown by sputtering. Evidence of the bcc structure in the Fe3Ga layers has been found. The diffraction peak related to this structure shifts to high angles with the annealing temperature. Also, we have observed a change in the microstructure of the Tb-Fe layers when the thickness layer is reduced in the as-grown heterostructures. Moreover, the Tb content is lower than 33% of the TbFe2 Laves phase and it depends on the layer thickness. The thermal treatments promote the increase of the Tb content, but only in the heterostructures with thick layers. The strong lattice mismatch between the Tb-Fe and Fe-Ga layers seems to prevent a complete Tb diffusion upon the annealing process. Thus, the crystallization of the TbFe2 Laves phase is inhibited in the heterostructures with thin layers, although our experimental results indicate the presence of potential magnetostrictive TbFeGa alloy

Diferenciación de carnes de jabalí europeo (Sus scrofa scrofa) y cerdo doméstico (Sus scrofa domestica) mediante el análisis por PCR de la región mitocondrial D-loop y el gen nuclear MC1R

En este trabajo se describe la diferenciación de carnes procedentes de jabalí europeo (Sus scrofa scrofa) y cerdo doméstico (Sus scrofa domestica) mediante el análisis por PCR de la región mitocondrial D-loop y del gen nuclear que codifica para el receptor 1 de la melanocortina (MC1R). La discriminación por PCR-RFLP de jabalí y cerdo en la región D loop no fue posible. Sin embargo, la técnica de PCR-RFLP desarrollada en el gen MC1R determinó perfiles de bandas característicos que permitieron la diferenciación de jabalí y cerdo mediante el empleo de las endonucleasas BspHI y BstUI.This work describes the differentiation of European wild boar (Sus scrofa scrofa) and domestic swine (Sus scrofa domestica) meats by PCR targeting sequences from the mitochondrial displacement loop (D-loop) region and the nuclear melanocortin receptor 1 (MC1R) gene. Detailed analysis of every D-loop sequence obtained indicated that PCR RFLP differentiation between wild and domestic Sus scrofa meats was not possible. Nevertheless, the PCR-RFLP technique developed targeting the MC1R gene generated characteristic PCR–RFLP profiles that allowed discrimination among meats from wild and domestic swine specimens using BspHI and BstUI endonucleases

The MIRAS “all-licef” calibration mode

Since each of the individual elements of the MIRAS array is a total power radiometer, the zero-spacing visibility can be obtained by the average of all the corresponding antenna temperatures. The main advantage of this option with respect to using the NIR measurements is that amplitude calibration is more consistent between zero-spacing visibility and the rest. On the other hand, total power radiometers are not usually as stable as noise injection radiometers, so a small loose of stability could be expected. Preliminary results show, however, similar performance.Peer ReviewedPostprint (author's final draft

Patterns of scuba diver behaviour to assess environmental impact on marine benthic communities: a suitable tool for management of recreational diving on Benidorm island (Western Mediterranean sea)

Few studies have analyzed the SCUBA divers’ behaviour in the Mediterranean Sea and none of them involved marine unprotected areas. Generally speaking the damage done by individuals is quite low, but the, accumulative effects of these disturbances can cause significant localised destruction of benthic marine organisms. The present study was carried out during the year 2005 on a diving site called La Llosa, on Benidorm Island (Alicante: Western Mediterranean Sea) with more than 7,000 dives per year. Two hundred and seventeen (217) divers were monitored randomly. Each subject was observed underwater for 10 minutes (Rouphael & Inglis, 2001). Samples were randomly collected during the high diving season (June-October). Divers were not aware of this surveillance so as not to interfere with their normal patterns of behaviour. The results showed that 95% of divers came into physical contact with benthic substrata during the 10-min observation period. Fin contact rates were significantly different depending on the diving certification level (Man-Whitney test, p<0.003) detecting the greatest number of contacts within higher diving certification levels (Bonferroni correction). Divers using an underwater light device came intocontact with the substratum significantly more frequently than non-light users (X2, p < 0.022). However, contact rate did not show significant variance across divers using a camera and those who did not (p<0.366). No difference was found between contact rates of divers who were given a briefing and those who were not. Environmental briefing before diving had no effect on the divers’ hand contact rates (X2, p<0.194), which shows a low marine environmental sensitivity level of divers. We concluded that the decrease in scuba divers contact rate would take place given an improvement of environmental awareness, specially among professional divers.Pocos estudios han analizado el comportamiento de los buceadores en el mar Mediterráneo y ninguno se ha centrado en las áreas marinas protegidas. El daño hecho por los buceadores suele ser bajo, pero los efectos acumulados, pueden ser importantes, aunque localizados. Este estudio se llevó a cabo durante el 2005 en una zona de buceo llamada La Llosa, cerca de Benidorm (Alicante, Mediterráneo occidental), con más de 7.000 inmersiones al año. La muestra aleatoria de buceadores llegó al tamaño 217. Se observó a cada buceador durante 10 minutos (Rouphael & Inglis, 2001), en la temporada alta (junio-octubre), de manera que los buceadores no supieran que eran vigilados, para no interferir en su comportamiento habitual. Los resultados mostraron que el 95% de los buceadores entran en contacto físico con los sustratos bentónicos durante el período de observación de 10 min. Las tasas de contacto fueron significativamente diferentes en función del nivel de certificación de buceo (Man-Whitney, p <0,003) detectándose mayor número de contactos en los niveles más altos de certificación de buceo (corrección de Bonferroni). Los buzos que utilizan linterna tuvieron un mayor número de contactos con el sustrato que los que no la usaron (X2, p < 0,022). Pero, no hubo diferentas significativas, entre los que llevaron cámara y no la llevaron (p < 0.366). Tampoco las hubo entre los buzos a los que se dio una conferencia previa a la inmersión y a los que no. La conferencia previa sobre medio ambiente no tuvo efecto sobre el número de contactos con las manos (X2, p < 0,194), lo que demuestra un bajo nivel de sensibilidad de los buceadores ante el medio ambiente marino. Se concluye que la disminución de la tasa de contacto de los buceadores se podría conseguir mejorando su conciencia medioambiental, especialmente la de los buceadores profesionales.Ciencias del Ma

Identificando actividades de matematización horizontal y vertical en un proceso de clasificación

La noción de matematización progresiva se expresa través de una secuencia generada por dos tipos de actividad matemática relacionadas reflexivamente: la matematización horizontal y la vertical (Treffers, 1987). Aunque, frecuentemente, la matematización horizontal se describe a través de la transformación de una situación problemática en un problema matemático propiamente dicho, en nuestro trabajo utilizaremos este concepto en un sentido más amplio que nos permitirá incluir situaciones de partida que sean de naturaleza ya matemática (Rasmussen, Zandieh, King & Teppo, 2005). Las actividades que pueden ser identificadas cuando se produce la matematización horizontal y la matematización vertical han sido descritas por Üzel y Mert Uyangör (2006)

Polymerase chain reaction detection of rabbit DNA in food and animal feed

[EN] A polymerase chain reaction (PCR) based on oligonucleotide primers targeting the mitochondrial 12S rRNA gene was developed for the specific identification of rabbit DNA (Oryctolagus cuniculus) in food and feedstuffs. The specificity of the primers was verified by PCR analysis of DNA from 32 non-target species including mammals, birds, fish, and plant species. Analysis of experimental mixtures demonstrated the presence of rabbit-derived materials in the range of 0.1-100%. Prolonged heat treatment (up to 133ºC for 20 min at 300 kPa) applied to rabbit muscle/oats binary mixtures did not affect the performance of the method, which could therefore be said to be very useful for the accurate identification of rabbit materials in products submitted to denaturing technologies when other methods are not suitable.This study was supported by Grant Nº. AGL 2007-60077 from the Spanish Ministerio de Educación y Ciencia and the Programa de Vigilancia Sanitaria S-0505/AGR/000265 of the Comunidad de Madrid (Spain). Irene Martín is the recipient of a fellowship from the Universidad Complutense de Madrid (Spain). Violeta Fajardo and María Rojas are recipients of fellowships from the Ministerio de Educación y Ciencia (Spain).Martín, I.; García, T.; Fajardo, V.; Rojas, M.; Pegels, N.; Hernández, P.; González, I.... (2009). Polymerase chain reaction detection of rabbit DNA in food and animal feed. World Rabbit Science. 17(1):27-34. doi:10.4995/wrs.2009.667273417

Natural and anthropogenic alterations of the soil affect body condition of the fossorial amphisbaenian Trogonophis wiegamnni in North Africa

Soil alteration is one of the major threats in arid environments, which can have serious consequences for soil biodiversity. However, the ecology of fossorial animals is poorly understood and their low conspicuousness may lead researchers and managers to overlook potential conservation problems. Amphisbaenians are fossorial reptiles and, because of their secretive habits, there is a chronic almost lack of data on their conservation state. Here, we examined the effects of diverse natural (salinization and seagulls influence) and anthropogenic factors (disturbance of the soil physical structure and lead contamination) that affect physical and chemical properties of the soil on body condition of Trogonophis wiegmanni amphisbaenians from the Chafarinas Islands, in North Africa. Results indicated that soil salinization and human induced mechanical disturbance and compaction of the soil affected negatively to body condition of amphisbaenians. In contrast, the increase in organic matter and heavy metals pollutants in the soil, either because of the seagull or anthropogenic influence, did not seem to affect body condition of amphisbaenians. We suggest potential management techniques to solve these problems and emphasize the need for periodic surveys of subterranean herpetofauna to prevent future conservation problems.Legal authorization and financial support was provided by the Organismo Autónomo de Parques Nacionales with additional financial support from a Ministerio de Ciencia e Innovación project (CGL2011-24150/BOS) and from the Regional Government of Andalusia project BIOGEOBIRD (P09-RNM-4987) and FEDER funds.Peer reviewe

Magnetoplasmonic Interferometers and Applications

Comunicación presentada en el 2nd Early Stage Researchers Workshop in Nanoscience, celebrado en Madrid el 28 y 29 de junio de 2012.Surface plasmons polaritons (SPP) are evanescent waves that propagate along a dielectric-metal interface. They can be confined in subwavelength metal structures, i.e. below the diffraction limit, which leads to many possible applications, including miniaturized optical devices. Within that context, the development of active plasmonics is important to achieve nanophotonic devices with advanced functionalities. This requires a system where the plasmon properties can be manipulated using an external agent. Among the different control agents considered so far, the magnetic field seems a promising candidate, since it is able to modify the dispersion relation of SPP at reasonable magnetic field strengths, and with a high switching speed. This modulation comes from the non-diagonal elements of the dielectric tensor, εij, appearing when the magnetic field is turned on. For noble metals, the ones typically used in plasmonics, these elements are proportional to the applied magnetic field but, unfortunately, very small at field values reasonable for developing applications. On the other hand, ferromagnetic metals have sizeable εij values at small magnetic fields (proportional to their magnetization), but are optically too absorbent. A smart system to develop magnetic field tunable plasmonic devices is the use of multilayers of noble and ferromagnetic metals. That is the framework of the present work, where we analyze the magnetic field induced SPP wavevector modulation (Ak) in Au/Co/Au films as a function of the wavelength and its possible application as a sensor.N

Slow growth of magnetic domains helps fast evolution routes for out-of-equilibrium dynamics

Cooling and heating faster a system is a crucial problem in science, technology, and industry. Indeed, choosing the best thermal protocol to reach a desired temperature or energy is not a trivial task. Noticeably, we find that the phase transitions may speed up thermalization in systems where there are no conserved quantities. In particular, we show that the slow growth of magnetic domains shortens the overall time that the system takes to reach a final desired state. To prove that statement, we use intensive numerical simulations of a prototypical many-body system, namely, the two-dimensional Ising model. © 2021 Published by the American Physical Societ