Probing the surface magnetic field structure in RX J1856.5-3754

The evolution of magnetic field in isolated neutron stars is one of the most important ingredients in the attempt to build a unified description of these objects. A prediction of field evolution models is the existence of an equilibrium configuration, in which the Hall cascade vanishes. Recent calculations have explored the field structure in this stage, called the Hall attractor. We use X-ray data of near-by, cooling neutron stars to probe this prediction, as these sources are surmised to be close to or at Hall attractor phase. We show that the source RX J1856.5-3754 might be closer to the attractor than other sources of its class. Our modelling indicates that the properties of surface thermal emission, assuming that the star is in the Hall attractor, are in contradiction with the spectral data of RX J1856.5-3754.Comment: 9 pages, accepted to MNRA

Fractional Brownian motions ruled by nonlinear equations

In this note we consider generalized diffusion equations in which the diffusivity coefficient is not necessarily constant in time, but instead it solves a nonlinear fractional differential equation involving fractional Riemann-Liouville time-derivative. Our main contribution is to highlight the link between these generalised equations and fractional Brownian motion (fBm). In particular, we investigate the governing equation of fBm and show that its diffusion coefficient must satisfy an additive evolutive fractional equation. We derive in a similar way the governing equation of the iterated fractional Brownian motion.Comment: 7 page

Natural Compounds: Molecular Weapons against Leukemia\u2019s

Nowadays cancer is one of the main reasons of death all over the world and it is estimated that deaths caused by cancer will grow dramatically in the next decades. Even if chemotherapy is the election therapy for solid tumors, as well as leukemias and lymphomas, cancer treatments are in continuous evolution trying to solve the problem of resistance mainly due to low accumulation of the drug in tumor cells (MDR). Natural compounds represent a valid alternative to treat several disease and recently the scientific community focus on these natural compounds and plant metabolites with therapeutic activities and low toxicities compared with synthetic ones. A combination therapy, that join conventional chemotherapy with natural plant metabolites, is now considered a new promising strategy to overcome MDR and reduce cellular toxicity; in particular, in leukemia due to its very complex origin and development of leukemogenesis. Here, we want to summarize and update the recent applications of natural compounds in the treatment of leukemia

Extracellular vesicles: Small bricks for tissue repair/regeneration

Extracellular vesicles (EVs) are nano-sized membrane vesicles involved in intercellular communication. EVs have pleiotropic actions in physiological and pathological conditions. The ability of EVs to transports proteins, drugs and nucleic acid, to target specific cells and to increase the stability of therapeutic cargo, make EVs interesting as new devices for the treatment of human disease. In a recently published issue of European journal of pharmaceutical sciences, Silva and colleagues reviewed the ability of EVs to modulate tissue repair and regeneration, focusing on their roles and therapeutic potential as immunomodulatory messengers. In this perspective, we discussed the open questions regarding the dual role of EVs in immune system, as well as the technical limitation of the procedure for EVs isolation and administration in clinical practices. EV-based therapies require further studies to consider EVs as promising candidate for a novel cell-free therapy in the context of regeneration medicine

A Comment on "A note on polarized light from Magnetars: QED effects and axion-like particles" by L.M. Capparelli, L. Maiani and A.D. Polosa

The recent detection of a large polarization degree in the optical emission of an isolated neutron star led to the suggestion that this has been the first evidence of vacuum polarization in a strong magnetic field, an effect predicted by quantum electrodynamics but never observed before. This claim was challanged in a paper by Capparelli, Maiani & Polosa (2017), according to whom a much higher polarization degree would be necessary to positively identify vacuum polarization. Here we show that their conclusions are biased by several inadequate assumptions and have no impact on the original claim.Comment: 10 pages, 2 figure

Teaching Words Through Picture-books: Early Learning of Nouns and Adjectives

El objetivo del trabajo que se informa fue investigar el aprendizaje de adjetivos y sustantivos mediante libros ilustrados en niños de tres años de edad. Se diseñaron dos estudios con una metodología cuasi-experimental en los que se enseñó a los niños un sustantivo o un adjetivo. Luego los participantes debían extender la palabra aprendida primero al objeto representado por la imagen, y luego a un nuevo ejemplar de la misma categoría de objeto (sustantivo) o propiedad de objeto (adjetivo). El Estudio 1 comparó el aprendizaje de sustantivos y adjetivos. Se encontró que los niños aprendieron el sustantivo pero no el adjetivo, lo que indicaría que para ellos aprender adjetivos a través de libros con imágenes es más difícil que aprender sustantivos. El Estudio 2 exploró el impacto de la información descriptiva sobre el aprendizaje de un adjetivo que refería a una propiedad visual (estampado). Esta información destacaba, por un lado, el núcleo del concepto, el estampado, y por otro la intención comunicativa del interlocutor. Se contrastó la ejecución de los niños en función de la información provista por la experimentadora. Los datos obtenidos muestran que si los niños reciben información descriptiva sobre el aspecto de la imagen que debe conectarse con la palabra, logran relacionarlo con la propiedad a la que refiere, aprendiendo el adjetivo. Los resultados de esta investigación aportan información relevante acerca de la relación entre el aprendizaje del lé- xico y el desarrollo conceptual y subrayan la relevancia del contexto sociopragmático en el aprendizaje de palabras.Picture-books reading are a very common practice between children and adults. In these interactions parents assume that their children learn lots of things, especially words. But, is this interaction effective as a word learning device? Is it the same to teach different kind of words? The main question of this research arises in the intersection of two fields: symbolic compre - hension of pictures and word learning. Three main ideas guided this research. Symbolic under - standing of pictures is a very complex process that involves cognitive and social skills. The sociopragmatic context has an impact in the cognitive processes involved in word learning. There is a strong relationship between word learning and conceptual development. The aim of this research was to explore 3-year-old children´s learning of nouns and adjectives in a picture-book reading situation. We designed two studies using a cuasiexperimental approach. In Study 1 we compared two groups of children: one learned a noun (category condition) and the other an adjective (property condition). The noun was pompe, a word that does not exist but has a Spanish morphologic structure. The adjective, pompeado, was built based on the word pompe, adding the suffix-ado; suffix marks that the word is an adjective. Toddlers were exposed to the new words during a picturebook reading interaction with the experimenter, then, they had to solve two successive tests. In the first test of the category condition participants had to apply the new noun learned via pictures to the real object. In the second test they had to extend the new noun to a new exemplar, an object with the same shape but different color. In the first test of the property condition, participants had to apply the new adjective learned via pictures to the real object with the property. In the second test they had to extend the adjective to a new exemplar, a new object with the same target-property. The second tests were taken as strong indicators of word learning as they involved some kind of generalization. In the first test both groups, category and property, applied the word to the real object. In the second test, while children in the category condition extended the noun to another exemplar, children in the property condition did not extend the adjective to another exemplar with the same property. In a second study we explored if children need more cues to extend the adjective to another exemplar with the same property, and truly learn the adjective. Study 2 investigated the impact of descriptive information in word learn - ing. We set two groups on the basis of the information provided by the experimenter. One group received descriptive information highlight - ing the specific aspect of the picture that had to be mapped with the property. The other group did not receive this additional information. We found that only the participants that received descriptive information extended the word pompeado to a new exemplar with the target property. We propose that the descriptive information worked high - lighting the communicative intention of the experimenter as well as the core of the concept. Underscoring the perceptual feature allowed much more than making a superficial association, as the descriptive information pointed directly to the heart of the concept. Overall, the results of this research are consistent with previous studies that found that it is more difficult for young children to learn adjectives than nouns. The results also highlight the strong relationship between word learning and conceptual development. This re - search provides strong evidence concerning the importance of socio the pragmatic context on referential understanding and word learning.Fil: Mareovich, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Abierta Interamericana; ArgentinaFil: Taverna, Andrea S.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Universitario del Gran Rosario; ArgentinaFil: Peralta, Olga Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentina. Universidad Abierta Interamericana; Argentin

Evidence of vacuum birefringence from the polarisation of the optical emission from an Isolated Neutron Star

Isolated Neutron Stars are some of the most exciting stellar objects known to astronomers: they have the most extreme magnetic fields, with values up to $10^{15}$ G, and, with the exception of stellar-mass black holes, they are the most dense stars, with densities of $\approx 10^{14}$ g cm$^{-3}$. As such, they are perfect laboratories to test theories of electromagnetism and nuclear physics under conditions of magnetic field and density unattainable on Earth. In particular, the interaction of radiation with strong magnetic fields is the cause of the {\em vacuum birefringence}, an effect predicted by quantum electrodynamics in 1936 but that lacked an observational evidence until now. Here, we show how the study of the polarisation of the optical radiation from the surface of an isolated neutron star yielded such an observational evidence, opening exciting perspectives for similar studies at other wavelengths.Comment: 5 pages, 1 figure, Contributed to the 13th Patras Workshop on Axions, WIMPs and WISPs, Thessaloniki, May 15 to 19, 201

The developmental pathways of preschool children with acute lymphoblastic leukemia: communicative and social sequelae one year after treatment

Early childhood is considered to be a period of rapid development, with the acquisition of abilities predicting future positive school competences. Motor, cognitive, and social diculties related to cancer therapies heavily impact the development of children with cancer. This study focused on two main aims: To assess the developmental pathways of preschool children with acute lymphoblastic leukemia one year post-treatment and to compare these abilities both with those of a control group of healthy peers and with Italian norms. Forty-four children and their families, recruited through the Hematology-Oncologic Clinic of the Department of Child andWoman Health (University of Padua), agreed to participate in this study. The children\u2019s mean age was 4.52 years (SD = 0.94, range = 2.5\u20136 years), equally distributed by gender, all diagnosed with acute lymphoblastic leukemia. Matched healthy peers were recruited through pediatricians\u2019 ambulatories. Each family was interviewed adopting the Vineland adaptive behavior scales. Paired sampleWilcoxon tests revealed that children were reported to have significantly more developmental diculties than their healthy peers. When compared with Italian norms, they scored particularly low in verbal competence, social, and coping skills. No significant association was found between treatment variables and developmental abilities. These findings suggest that the creation of specialized interventions, both for parents and children, may fill the possible delays in children\u2019s development probably due to stress, lack of adequate stimulation, or dicult adaptation

Predição do poder calorífico em Eucalyptus grandis através da espectroscopia de infravermelho próximo (NIR).

EVINCI. Resumo 043