Spin separation in digital ferromagnetic heterostructures

In a study of the ferromagnetic phase of a multilayer digital ferromagnetic semiconductor in the mean-field and effective-mass approximations, we find the exchange interaction to have the dominant energy scale of the problem, effectively controlling the spatial distribution of the carrier spins in the digital ferromagnetic heterostructures. In the ferromagnetic phase, the majority and minority carriers tend to be in different regions of the space (spin separation). Hence, the charge distribution of carriers also changes noticeably from the ferromagnetic to the paramagnetic phase. An example of a design to exploit these phenomena is given.Comment: 4 pages, 3 figures. Submitted to Phys. Rev.

Variables predictors of the set in the defence complex in volleyball

El objetivo de la investigación fue conocer las variables predictoras de la eficacia de colocación en el complejo de defensa (KII), en ambos géneros, en categorías de formación. La muestra del estudio estuvo compuesta por 2.404 acciones de juego, 1.104 en género masculino y 1.300 en género femenino, desarrolladas por los 34 equipos participantes en el Campeonato de España Under 16. La variable dependiente fue la eficacia de colocación. Las variables independientes se agruparon en: variables de defensa, de colocación en KII y de bloqueo. Los resultados determinaron que, en ambos géneros, la eficacia de defensa, la técnica de colocación y la participación en bloqueo predecían la eficacia de la colocación; en género masculino, zona de defensa y tiempo de colocación; ninguna variable fue predictora únicamente en género femenino. Esta información puede ser relevante para el desarrollo del proceso de entrenamiento en voleibolThe objective of the research was to analyse the variables predictors of the setting efficacy in the defence complex (KII), in youth athlete, in both genders. The study sample was comprised of 2404 game actions, 1104 in the male gender and 1300 in the female gender. The actions were carried out by the 34 teams that participated in the Spanish Under-16 Championship. The dependant variable was the setting efficacy. The results determined that, in both genders, the dig efficacy, setting technique and the participation in block predicted the setting efficacy; in male gender, the defence zone and tempo of set; no predictor variables were exclusive to the female gender. This information may be relevant when developing training processes in volleyballEste estudio se ha realizado gracias a la aportación de la Consejería de Economía e Infraestructuras de la Junta de Extremadura a través del Fondo Europeo de Desarrollo Regiona

Specific increase of a mitochondrial RNA transcript in chronic ethanol-fed rats

AbstractAn in vitro transcription system utilizing isolated mitochondria has been used to study the effect of chronic ethanol consumption on liver mitochondrial DNA transcription. The results obtained showed an overall increase of RNA synthesis and a dramatic accumulation of a discrete polyadenylated RNA species. This effect is a consequence of the chronic ethanol consumption since these changes do not occur when isolated control mitochondria are incubated in the presence of ethanol

End-on PEGylation of heparin: Effect on anticoagulant activity and complexation with protamine

Supplementary data to this article can be found online at https://doi.org/10.1016/j.ijbiomac.2023.125957.Heparin is the most common anticoagulant used in clinical practice but shows some downsides such as short half- life (for the high molecular weight heparin) and secondary effects. On the other hand, its low molecular weight analogue cannot be neutralized with protamine, and therefore cannot be used in some treatments. To address these issues, we conjugated polyethylene glycol (PEG) to heparin reducing end (end-on) via oxime ligation and studied the interactions of the conjugate (Hep-b-PEG) with antithrombin III (AT) and protamine. Isothermal titration calorimetry showed that Hep-b-PEG maintains the affinity to AT. Dynamic light scattering demonstrated that the Hep-b-PEG formed colloidal stable nanocomplexes with protamine instead of large multi-molecular aggregates, associated with heparin side effects. The in vitro (human plasma) and in vivo experiments (Sprague Dawley rats) evidenced an extended half-life and higher anticoagulant activity of the conjugate when compared to unmodified heparin.  The authors thank INNO Laboratório Veterinário for the measurements of in vivo coagulation times, Raul Pacheco for discussions about the ITC results, Teresa Oliveira for her help in the in vivo experiments and Ramón Rail for his help in the 3D structures of Fig. 1, Fig. 4. We thank funding provided by the Portuguese Foundation for Science and Technology (PTDC/QUI-POL/28117/2017 and CEECIND/00814/2017). África González-Fernández thanks Xunta de Galicia (Grupo de Referencia competitiva, GRC-ED431C 2020/02) 2020-2023

Evaluación de la atención en deportistas de artes marciales : expertos vs. novatos

El objetivo del estudio fue determinar las diferencias en el desempeño de una tarea de atención en relación con la pericia en artes marciales. Participaron 12 deportistas de artes marciales expertos y 13 novatos. Se les aplicó el Test of Variables of Attention (Greenberg, 1996) y se analizaron los datos de la prueba para cada variable, condición y segmentos en los que se divide, con un método estadístico no-paramétrico de permutaciones. Las comparaciones intergrupos indicaron una tendencia a que el puntaje global de Trastorno por Déficit de Atención e Hiperactividad (TDAH) de la prueba fuera mejor en los expertos que en los novatos. Se hizo un análisis intragrupo para conocer el comportamiento de cada grupo a lo largo de la prueba; los resultados indicaron que los deportistas expertos muestran mayor consistencia en el número de aciertos y tiempos de reacción a lo largo de la prueba, lo que se traduce como un mejor desempeño cuando se compara con la forma en que los deportistas novatos responden a la tarea. Los resultados sugieren que el entrenamiento físico y mental de las disciplinas de artes marciales podría producir una mejora en las capacidades de atención de los deportistas.The aim of this study is to determine differences in the performance of an attention-related task involving martial arts skills. 12 expert martial arts athletes and 13 novices took part, performing the Test of Variables of Attention (Leark, Greenberg, Kindschi, Dupuy and Hughes, 2007). Using a non-parametric statistical permutation method, the test data for each variable, condition and segment of the test was analysed. Comparisons of the groups showed a trend toward a higher global Attention Deficit Hyperactivity Disorder (ADHD) score by the expert athletes as compared with the novices. In order to find out each group's performance during the test, a statistical intra-group analysis was performed. Generally, the results revealed more consistent accuracy and response times by the experts than by the novice athletes. The results suggest that physical and mental training in the martial arts may increase the attention skills of sportsmen and women.O objectivo do estudo foi determinar as diferenças no desempenho de uma tarefa atencional tendo em conta a perícia em artes marciais.Participaram no estudo 12 desportistas especialistas em artes marciais e 13 iniciantes. Foi aplicado aos participantes o Test of Variables of Attention (Greenberg, 1996) e analisaram-se os dados do teste para cada variável, condição e segmentos em que se dividem, através de um método estatístico nãoparamétrico de permutações. As comparações intergrupos indicaram uma tendência para que a pontuação global de Transtorno do Défice de Atenção e Hiperactividade (TDAH) fosse maior nos especialistas do que nos iniciantes. Foi realizada uma análise intragrupo para conhecer o comportamento de cada grupo ao longo da prova; os resultados indicaram que os desportistas especialistas revelaram maior consistência no número de acertos e tempos de reacção ao longo da prova, o que se traduz num melhor desempenho quando comparados com a forma como os desportistas iniciantes respondem à tarefa. Os resultados sugerem que o treino físico e mental das disciplinas de artes marciais poderia produzir uma melhoria nas capacidades atencionais dos desportistas

Shallow structure beneath the Central Volcanic Complex of Tenerife from new gravity data: implications for its evolution and recent reactivation

We present a new local Bouguer anomaly map of the Central Volcanic Complex (CVC) of Tenerife, Spain, constructed from the amalgamation of 323 new high precision gravity measurements with existing gravity data from 361 observations. The new anomaly map images the high-density core of the CVC and the pronounced gravity low centred in the Las Cañadas caldera in greater detail than previously available. Mathematical construction of a sub-surface model from the local anomaly data, employing a 3D inversion based on 'growing' the sub-surface density distribution via the aggregation of cells, enables mapping of the shallow structure beneath the complex, giving unprecedented insights into the sub-surface architecture. We find the resultant density distribution in agreement with geological and other geophysical data. The modelled sub-surface structure supports a vertical collapse origin of the caldera, and maps the headwall of the ca. 180 ka Icod landslide, which appears to lie buried beneath the Pico Viejo–Pico Teide stratovolcanic complex. The results allow us to put into context the recorded ground deformation and gravity changes at the CVC during its reactivation in spring 2004 in relation to its dominant structural building blocks. For example, the areas undergoing the most significant changes at depth in recent years are underlain by low-density material and are aligned along long-standing structural entities, which have shaped this volcanic ocean island over the past few million years

Unstable spectrum of a relativistic electron beam interacting with a quantum collisional plasma: application to the Fast Ignition Scenario

Quantum and collisional effects on the unstable spectrum of a relativistic electron beam-plasma system are investigated through a two-fluids model. Application is made to the near target center interaction of the relativistic electron beam in the Fast Ignition Scenario. Partial degeneracy effects are found negligible while the most influential factors are the beam temperature and the electron-ion collision frequency of the plasma. The introduction of the latter triggers some oblique unstable modes of much larger wave length than the collisionless ones. Transition from the collisionless regime to the resistive one is thus documented and found discontinuous.Comment: To appear in PPC

Biotic homogenization of oceanic islands depends on taxon, spatial scale and the quantification approach

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