The confined hydrogen atom with a moving nucleus

We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first--order perturbation theory and by a more accurate variational approach. We show that it is greater than the one for the case in which the nucleus is clamped at the center of the box. Present approach resembles the well-known treatment of the helium atom with clamped nucleus

Aplicaciones del uso de la técnica de espectroscopía de reflectancia difusa en química forense para la carcterización de autenticidad de los sellos de correos de España

Dentro del área de las Ciencias Forenses, la Documentoscopia es una de sus secciones más atractivas. Tan atractiva como es la Filatelia, el coleccionismo de efectos postales, en el mundo moderno. La Espectroscopía de Reflectancia Difusa, debido a tener como principal característica el ser una técnica no destructiva y de fácil manejo, puede ser una herramienta de gran valor para el estudio de la autenticidad de piezas filatélicas. En este trabajo, presentamos un análisis cualitativo de varios sellos antiguos españoles procedentes de diferentes emisiones desde el reinado de Isabel II hasta Alfonso XIII, profundizando en la Serie del Gobierno Provisional de 1870 -caracterizada por la profusión de los variados colores encontrados a lo largo de los 13 valores que componen la serie completa-, e incluso estudiando efectos auténticos frente a otros ejemplares falsos indubitadosIn the area of forensic sciences, the questioned document examination is one of its most attractive sections. As attractive as philately, the collecting of postal effects, in the modern world. Diffuse reflectance spectroscopy, due to have as main characteristic being a technique of non-destructive and easy to use, can be a tool of great value to the study of the philatelic pieces authenticity. In this work, using Diffuse Reflectance Spectroscopy, we present qualitative analysis of several early Spanish stamps issued from different emissions since the reign of Queen Isabel II to King Alfonso XIII, deepening over the series of the Provisional Government issued in 1870 - characterized by the profusion of variations of the colors found among the 13 values that compose the complete series-, and even studying authentic effects against other counterfeit recognized as fake copies

A model of maxilla resection to test new hybrid implants:macroporous titanium and tissue engineering elements

Maxillary bone loss in commonly found in humans, due to bone ageing, tooth loos, periodontal disease and, more severely, to trauma, radiotherapy and tumor resection. Masillofacial reconstructive surgery is a still unmet clinical demand, available therapies include grafting of autologous or heterologous bone tissue and/or the implantation of metallic plates, buy these treatments are still unable to resume form and function. The emrgence of 3D-printing technology applied to metal alloys now allows the manufacturing of customized, patient-tailored prosthetic implants. However, poor bone quiality at the implant site due to ageing or disease still hamper proper osseointegration. By combining Electron Beam Melting metal sintering and tissue engineering, we are developing hybrid maxillofacial implants, wher a metal framework of Ti6Al4V alloy confers both and appropiaate shape and mechanical stabilty, while stem cells and osteogenic molecules stimulate bone growth into the metal framework, thus pormoting osseointegration. We hereby present the in vitro work driving to the development of our hybrid maxillofacial prostheses, as well as the setting up of an in vivo model of complete maxilla full resection, created in order to test the prostheses in a preclinical studyUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Tycho Brahe's supernova: light from centuries past

The light curve of SN 1572 is described in the terms used nowadays to characterize SNeIa. By assembling the records of the observations done in 1572--74 and evaluating their uncertainties, it is possible to recover the light curve and the color evolution of this supernova. It is found that, within the SNe Ia family, the event should have been a SNIa with a normal rate of decline, its stretch factor being {\it s} $\sim$ 0.9. Visual light curve near maximum, late--time decline and the color evolution sustain this conclusion. After correcting for extinction, the luminosity of this supernova is found to be M$_{V}$ $=$ --19.58 --5 log (D/3.5 kpc) $\pm$ 0.42.Comment: 28 pages, 3 figures, 3 tables. submitted to ApJ (Main Journal

Active Learning Methodologies in Teacher Training for Cultural Sustainability

Within the framework of sustainable development, the concept of cultural heritage is linked to the heritage awareness of a specific spatial context, and to the conservation of collective memory. Despite the clear interest in cultural sustainability, the lack of research devoted to interpreting different teaching methods for transmitting patrimonial assets and preserving natural heritage is noteworthy. For this reason, the present study takes various scientific contributions as the background for considering sustainable education as a fundamental instrument to recover and conserve heritage resources, both from an informative and educational point of view. The aim of this study was to assess the training of new teachers in terms of the particular skills needed to develop active learning methods related to the teaching of heritage sustainability. The research sample consisted of 488 students in the Degree in Primary Education program. The methodology combined both qualitative and quantitative techniques, to obtain information from both observation and an opinion survey given to the students. The results show several opinions related to achieving and facilitating the implementation of innovative methodologies, due to a lack of initial university training. Generally speaking, this work provided an opportunity for students to analyze a series of prejudices regarding their working methods, and to overcome excessive theorization in their university studies

Measurement of the Bs0-Bs0 oscillation frequency δms in Bs0→Ds-(3)π decays

The Bs0-Bs0 oscillation frequency δms is measured with 36 pb-1 of data collected in pp collisions at s=7TeV by the LHCb experiment at the Large Hadron Collider. A total of 1381 Bs0→Ds-π+ and Bs0→Ds-π+π-π + signal decays are reconstructed, with average decay time resolutions of 44 fs and 36 fs, respectively. An oscillation signal with a statistical significance of 4.6σ is observed. The measured oscillation frequency is δm s=17.63±0.11(stat)±0.02(syst)ps -1

Antiglycative effect of fruit and vegetable seed extracts: Inhibition of AGE formation and carbonyl-trapping abilities

BACKGROUND: Advanced glycation end-products (AGEs) are the final products derived from the non-enzymatic glycation process. AGEs are involved in the development of several health complications associated with diabetes and aging. Searching for anti- AGE extracts is necessary to mitigate the effects of age-related pathologies. RESULTS: The antioxidant and antiglycative activities of eight aqueous extracts of fruit and vegetable seeds were evaluated. All seed extracts (3.6 mg mL-1) exhibited anti-AGE activity in protein-glucose assay, ranging from 20 to 92% inhibition compared with aminoguanidine (4.87 mmol L-1). Green pepper extract exerted the highest anti-AGE activity. However, peach and pomegranate extracts exhibited the highest anti-AGE activity in protein-methylglyoxal assay, ranging from 0 to 79% inhibition. Hazelnut, almond and sesame extracts were not effective when methylglyoxal was the promoter. Apricot and peach extracts appeared to inhibit the formation of AGEs through their capacity for direct trapping of 1,2-dicarbonyls (IC50=0.14 mg mL-1). No relationship between antioxidant and phenolic compound content and antiglycative activity was found. Therefore other hydrophilic constituents in addition to phenolic acids must be involved in the antiglycative activity of the extracts. CONCLUSION: Aqueous extracts of fruits and vegetables can be considered in the prevention of glycation-associated complications of age-related pathologies. © 2012 Society of Chemical Industry.Peer Reviewe

The SCOFF-c: Psychometric properties of the Catalan version in a Spanish adolescent sample

Objective The objective of this study is to validate the Catalan version of the SCOFF questionnaire with a community sample of adolescents. Method This study used a community sample of 954 participants (475 girls and 479 boys; aged between 10.9 and 17.3 years and from the city of Barcelona) and a risk group of 78 participants (35 men and 43 women; derived from the community sample) that have exceeded ≥95 percentile in at least two of the three scales of the Eating Disorders Inventory-2 (EDI-2): Drive for Thinness, Bulimia, and Body Dissatisfaction. Results There were significant differences in total SCOFF scores across gender and school grades. The SCOFF best cutoff point was 2 (sensitivity=73.08%; specificity=77.74%). Concurrent validity with the EDI-2 varied between low and moderate. The reliability of the SCOFF questionnaire was moderate. Exploratory factor analysis of the SCOFF questionnaire showed a two-factor structure for the total sample and for girls, and one factor for boys. Conclusion The best cutoff point for this community sample is 2. The data suggest that the SCOFF questionnaire could be a useful screening questionnaire to enable the detection of groups possibly at risk for eating disorders among adolescent Spanish community samples

Atomistic Origin of Urbach Tails in Amorphous Silicon

Exponential band edges have been observed in a variety of materials, both crystalline and amorphous. In this paper, we infer the structural origins of these tails in amorphous and defective crystalline Si by direct calculation with current {\it ab initio} methods. We find that exponential tails appear in relaxed models of diamond with suitable point defects. In amorphous silicon (a-Si), we find that structural filaments of short bonds and long bonds exist in the network, and that the tail states near the extreme edges of both band tails are are also filamentary, with much localization on the structural filaments. We connect the existence of both filament systems to structural relaxation in the presence of defects and or topological disorder.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let