Signal modeling of high-purity Ge detectors with a small read-out electrode and application to neutrinoless double beta decay search in Ge-76

The GERDA experiment searches for the neutrinoless double beta decay of Ge-76 using high-purity germanium detectors enriched in Ge-76. The analysis of the signal time structure provides a powerful tool to identify neutrinoless double beta decay events and to discriminate them from gamma-ray induced backgrounds. Enhanced pulse shape discrimination capabilities of "Broad Energy Germanium" detectors with a small read-out electrode have been recently reported. This paper describes the full simulation of the response of such a detector, including the Monte Carlo modeling of radiation interaction and subsequent signal shape calculation. A pulse shape discrimination method based on the ratio between the maximum current signal amplitude and the event energy applied to the simulated data shows quantitative agreement with the experimental data acquired with calibration sources. The simulation has been used to study the survival probabilities of the decays which occur inside the detector volume and are difficult to assess experimentally. Such internal decay events are produced by the cosmogenic radio-isotopes Ge-68 and Co-60 and the neutrinoless double beta decay of Ge-76. Fixing the experimental acceptance of the double escape peak of the 2.614 MeV photon to 90%, the estimated survival probabilities at Qbb = 2.039 MeV are (86+-3)% for Ge-76 neutrinoless double beta decays, (4.5+-0.3)% for the Ge-68 daughter Ga-68, and (0.9+0.4-0.2)% for Co-60 decays.Comment: 27 pages, 17 figures. v2: fixed typos and references. Submitted to JINS

TL1A/DR3 axis involvement in the inflammatory cytokine network during pulmonary sarcoidosis

BACKGROUND: TNF-like ligand 1A (TL1A), a recently recognized member of the TNF superfamily, and its death domain receptor 3 (DR3), firstly identified for their relevant role in T lymphocyte homeostasis, are now well-known mediators of several immune-inflammatory diseases, ranging from rheumatoid arthritis to inflammatory bowel diseases to psoriasis, whereas no data are available on their involvement in sarcoidosis, a multisystemic granulomatous disease where a deregulated T helper (Th)1/Th17 response takes place. METHODS: In this study, by flow cytometry, real-time PCR, confocal microscopy and immunohistochemistry analyses, TL1A and DR3 were investigated in the pulmonary cells and the peripheral blood of 43 patients affected by sarcoidosis in different phases of the disease (29 patients with active sarcoidosis, 14 with the inactive form) and in 8 control subjects. RESULTS: Our results demonstrated a significant higher expression, both at protein and mRNA levels, of TL1A and DR3 in pulmonary T cells and alveolar macrophages of patients with active sarcoidosis as compared to patients with the inactive form of the disease and to controls. In patients with sarcoidosis TL1A was strongly more expressed in the lung than the blood, i.e., at the site of the involved organ. Additionally, zymography assays showed that TL1A is able to increase the production of matrix metalloproteinase 9 by sarcoid alveolar macrophages characterized, in patients with the active form of the disease, by reduced mRNA levels of the tissue inhibitor of metalloproteinase (TIMP)-1. CONCLUSIONS: These data suggest that TL1A/DR3 interactions are part of the extended and complex immune-inflammatory network that characterizes sarcoidosis during its active phase and may contribute to the pathogenesis and to the progression of the disease

Sperimentazione di una App di Realt\ue0 Aumentata per comunicare il Patrimonio Culturale: l\u2019Hestercombe Gardens Augmented Visit

Questa esperienza ha avuto luogo in Inghilterra, in Somerset, presso i giardini di Hester- combe. In questo contesto il nostro obiettivo era quello di verificare se l\u2019utilizzo guidato di una App di realt\ue0 mista/aumentata, unita ad una corretta metodologia didattica e con un affiancamento di una guida, possa aiutare gli studenti di classi delle scuole primarie e secondarie a migliorare l\u2019apprendimento dei contenuti storici, artistici e culturali del giardino. Nel paper viene presentata la fase di sviluppo tecnico dell\u2019interfaccia della App e la sua successiva sperimentazione. Dalle prime verifiche sul campo, emerge come il processo di interazione tra Studente/App/Guida sia significativamente pi\uf9 efficace sia nella dimensione dell\u2019attenzione che in quella della memorizzazione dei contenuti ri- spetto ad un utilizzo della App senza alcuna interazione

About the parabolic relation existing between the skewness and the kurtosis in time series of experimental data

In this work we investigate the origin of the parabolic relation between skewness and kurtosis often encountered in the analysis of experimental time-series. We argue that the numerical values of the coefficients of the curve may provide informations about the specific physics of the system studied, whereas the analytical curve per se is a fairly general consequence of a few constraints expected to hold for most systems.Comment: To appear in Physica Script

Efectos de la Exención Tributaria a las Ganancias de Capital en el Precio de las Acciones en Chile

La Reforma al Mercado de Capitales de 2001 en Chile (MK I), estableció la exención del impuesto a la renta para las ganancias de capital provenientes de la enajenación de acciones con presencia bursátil mayor al 25%. Los objetivos de la reforma eran aumentar la participación, la profundidad y la liquidez en el mercado local de acciones. Sin embargo, no es evidente cuál es el efecto que tiene una rebaja tributaria en el precio de las acciones ya que hay dos efectos que actúan en sentido contrario. Por un lado, hay un efecto de capitalización que lleva a un aumento en los precios. Por otro lado, hay un efecto lock-in que lleva a una reducción en los precios. Determinar cuál efecto domina es, por lo tanto, una pregunta que debe responderse empíricamente. Este trabajo contribuye a responder esa pregunta, determinando empíricamente los efectos que tuvo la exención tributaria introducida en 2001 en el precio de las acciones en Chile. Utilizando un estimador de diferencias en diferencias, los resultados muestran un impacto anticipado promedio de alrededor de -14% en el precio de las acciones que se cotizan en la Bolsa de Santiago frente a la futura exención tributaria. La elasticidad del precio respecto a la tasa de impuesto, entre 0.006 y 0.01, es mucho menor a la estimada en la literatura económica para otros países a partir de reformas similares, donde la elasticidad fluctúa entre 0.20 y 0.27. Sin embargo, es de magnitud similar a la elasticidad estimada para períodos de tiempo donde el efecto lock-in domina.Ganancias de Capital, Incidencia Tributaria, Mercado de Capitales, Precio de Acciones.

Attosecond pulse shaping around a Cooper minimum

High harmonic generation (HHG) is used to measure the spectral phase of the recombination dipole matrix element (RDM) in argon over a broad frequency range that includes the 3p Cooper minimum (CM). The measured RDM phase agrees well with predictions based on the scattering phases and amplitudes of the interfering s- and d-channel contributions to the complementary photoionization process. The reconstructed attosecond bursts that underlie the HHG process show that the derivative of the RDM spectral phase, the group delay, does not have a straight-forward interpretation as an emission time, in contrast to the usual attochirp group delay. Instead, the rapid RDM phase variation caused by the CM reshapes the attosecond bursts.Comment: 5 pages, 5 figure

Supercritical Extraction from Vinification Residues: Fatty Acids, α-Tocopherol, and Phenolic Compounds in the Oil Seeds from Different Varieties of Grape

Supercritical fluid extraction has been widely employed in the extraction of high purity substances. In this study, we used the technology to obtain oil from seeds from a variety of grapes, from vinification residues generated in the Southern region of the state of Rio Grande do Sul, Brazil. This work encompasses three varieties of Vitis vinifera (Moscato Giallo, Merlot, and Cabernet Sauvignon) and two of Vitis labrusca (Bordô e Isabel), harvested in 2005 and 2006. We obtained the highest oil content from Bordô (15.40%) in 2005 and from Merlot (14.66%), 2006. The biggest concentration of palmitic, stearic, and linoleic acids was observed in Bordô, 2005, and in Bordô, Merlot, and Moscato Giallo, 2006. Bordô showed the highest concentration of oleic acid and α-tocopherol in both seasons too. For the equivalent of procyanidins, we did not notice significant difference among the varieties from the 2005 harvest. In 2006, both varieties Isabel and Cabernet Sauvignon showed a value slightly lower than the other varieties. The concentration of total phenolics was higher in Bordô and Cabernet Sauvignon. The presence of these substances is related to several important pharmacological properties and might be an alternative to conventional processes to obtain these bioactives