Pontryagin Term and Magnetic Mass in 4D AdS Gravity

Indexación: Scopus.In the context of the anti-de Sitter/Conformal Field Theory (AdS/CFT) correspondence, 4D AdS gravity is suitably renormalized by adding the Gauss Bonnet term to the Einstein-Hilbert action. The subsequent addition of the Pontryagin term, with a specific coupling, allows to write the on-shell action in terms of the Weyl tensor and its dual, such that the action becomes stationary for asymptotic (anti) self-dual solutions in the Weyl tensor. The addition to the action of both topological invariants mentioned above does not modify the bulk dynamics, but it does modify the expression of the Noether current and, therefore, the conserved quantities of the theory. Here, we show that the method of Iyer and Wald leads to a fully-covariant Noether charge, which contains both the electric and magnetic parts of the Weyl tensor. For configurations which are globally (anti) self-dual in the Weyl tensor, both the action and the Noether charge identically vanish. This means that, for such spacetimes, the magnetic mass is equal to the electric mass. © Published under licence by IOP Publishing Ltd.This work was funded in part by FONDECYT Grants No. 1131075, 1140296 and 1151107, CONICYT Grant DPI 2014-0115, UNAB Grants DI-735-15/R and DI-1336-16/RG and VRIEA-PUCV Grant 039.345/2016. R.Araneda received financial support from Facultad de Física, Pontificia Universidad Católica de Chile to participate in SOCHIFI Congress.https://iopscience.iop.org/article/10.1088/1742-6596/1043/1/01201

Evaluation of the hygienic behavior of Apis mellifera L. related to the level of infestation of varroa destructor Anderson & Trueman

The beekeeping in Chile has been especially important for the small and medium agriculture due to the several products that can be obtained from the explotation. One of the major problems is the incidence of diseases and parasites, being the acarus ectoparasite Varroa destructor Anderson & Trueman one of the main pathologies because of its difficult control since it's reproduced in brood capped cells, decreasing the population of the colony and in strong infestations making them disappear completely; also by using chemical products for its control, which are not used correctly, producing resistance and leaving residues in the bee products. In order to change this situation it is necessary to find new control alternatives such as genetic resistance through hygienic behavior. The hygienic behavior related to the infestation level of Varroa destructor is analyzed in this work. Twenty one honeybee colonies were involved in this study, which were evaluated from October to December 2005. The percentage of hygienic behavior of each colony was determined through the pin-killed test. Samples to carry out the diagnoses of varroa were also taken. The results showed a low and heterogeneous level of hygienic behavior, where the values fluctuated in the colonies in average from 20% to 80% (2 colonies). The non-existence of correlation was also shown. The evaluated parameters showed an infestation average of 4.5% in adult bee; 7% in worker brood and 31% in drone brood.La apicultura en Chile ha sido importante sobre todo para la pequeña y mediana agricultura, por los diversos productos que se pueden extraer de esta explotación, pero uno de los mayores problemas son la incidencia de enfermedades y parásitos. Una de las principales patologías es el ácaro ectoparásito Varroa destructor Anderson & Trueman, debido a su difícil control, ya que se reproduce en celdas operculadas de cría, disminuyendo la población de la colonia y en infestaciones severas haciéndola desaparecer por completo; además de la utilización de productos químicos para su control, los cuales no son usados correctamente, creando resistencia y dejando residuos en los productos de origen apícola. Para revertir esta situación se hace necesario buscar nuevas alternativas de control, tales como la resistencia genética, por medio del comportamiento higiénico. En este estudio se analiza el comportamiento higiénico en relación al nivel de infestación de Varroa destructor. Para la elaboración de este estudio se utilizaron veintiuna colonias de abejas melíferas, las cuales se evaluaron desde octubre a diciembre del año 2005. A cada colonia se le determinó el porcentaje de comportamiento higiénico a través de la técnica del perforado; conjuntamente se tomaron muestras para realizar los diagnósticos de detección de Varroa. Los resultados evidenciaron un bajo y heterogéneo nivel de comportamiento higiénico, donde los valores fluctuaron en promedio en las colonias desde 20% a 80% (2 colonias) y la inexistencia de correlación. Los parámetros evaluados presentaron infestaciones promedio de: abeja adulta 4,5%; cría obrera 7% y cría de zángano 31%

Synthesis, characterization of a new carbonylated zirconium metallocene using a dichloro-zirconocene derived from partially alkylated s-indacene

Indexación: ScieloThis work describes the synthesis and characterization of new organometallic species, an unprecedented mononuclear zirconium complex bearing a tetraalkylated s-indacene ligand, and secondly, its respective dicarbonyl complex obtained by reduction with Mg/HgCl2. Theoretical calculations of these two compounds were carried out to gain further understanding of these novel molecular systems.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-97072009000300014&lng=es&nrm=is

Propuestas de reformas al derecho canónico presentadas por el arzobispo de Tarragona, Tomás Costa y Fornaguera, al iniciarse la codificación del derecho canónico de 1917

Based on documents in the Vatican Secret Archives, this paper presents the proposals for canon law reform made in 1904 by Tomás Costa y Fornaguera, Archbishop of Tarragona, in response to the Pergratum mihi circular issued by the Vatican Secretariat of State, 25 March 1904, at the start of the 1917 Canon Law codification process, and offers a first assessment of both texts.A partir de documentos del Archivo Secreto Vaticano, se presentan las propuestas de reformas al derecho canónico hechas en 1904 por el arzobispo de Tarragona, Tomás Costa y Fornaguera, en respuesta a la circular Pergratum mihi de la Secretaria de Estado del Vaticano, de 25 de marzo de 1904, al iniciarse la codificación del derecho canónico de 1917 y se hace una primera valoración de conjunto de ellas

Motion analysis of a trapped ion chain by single photon self-interference

We present an optical scheme to detect the oscillations of a two-ion string confined in a linear Paul trap. The motion is detected by analyzing the intensity correlations in the fluorescence light emitted by one or two ions in the string. We present measurements performed under continuous Doppler cooling and under pulsed illumination. We foresee several direct applications of this detection method, including motional analysis of multi-ion species or coupled mechanical oscillators, and sensing of mechanical correlations.Comment: 6 pages, 5 figure

Azadirachtin effectivity in embryogenesis inhibition of Aegorhinus superciliosus (Guérin) (Coleoptera: Curculionidae)

Raspberry is cultivated in the southern part of Chile mainly for export. Its fruit is severely affected by the raspberry weevil (RW) Aegorhinus superciliosus (Guérin), a Curculionidae native of Chile. Little is known about the biology RW and control measures. Conventional insecticides have been tried against the adult, however, their use has been hindered in the practice by the coincidence of the presence of the mature insect with flowering and fructification periods. Entomopathogenic fungi are being incorporated lately, but still not massively used. This work aimed to evaluate azadirachtin, using the commercial product Neem as a growth regulator. Six doses of Neem, 0.5, 1, 2, 3, 4, and 5 ml/L of water, were applied under laboratory conditions, maintaining a check with no insecticide. RW adults stayed confined on the foliage of raspberry bushes treated with Neem during five days and in thirty days during egglaying. Number of eggs, number of emerged larva, percentage of born larva, effectiveness; effective half dose (DE50) and ninety effective dose (DE90) were determined. Neem treatments had significantly lower egg-laying amount, lower emergence of larvae and greater effectiveness, compared to the untreated check. The lowest egg-laying number was obtained with 2 ml of Neem, however, 5 ml of Neem resulted in the smallest number and percent of emerged larvae. DE50 and DE90 were found to be 0.0290 and 8.923 ml of Neem for liter of water, respectively. It was concluded that Neem can significantly alter egg-laying and embryogenesis of the RW.La frambuesa es una fruta de exportación, cuyo cultivo en el sur de Chile es afectado seriamente por el curculiónido Aegorhinus superciliosus (Guérin) o cabrito del frambueso (CF), insecto nativo de Chile. La biología del CF es poco conocida y también su control. Se ha intentado reducir al adulto con insecticidas convencionales; sin embargo, en la práctica se dificulta su uso por coincidir la presencia del insecto adulto con periodos de floración y cosecha de fruta. Recientemente se están incorporando hongos entomopatógenos, pero aún no se aplican masivamente. En este trabajo se experimentó con azadirachtina, utilizando el producto comercial Neem como regulador de crecimiento. Bajo condiciones de laboratorio se aplicaron seis dosis de Neem: 1 ml; 2 ml; 3 ml; 4 ml; 5 ml; 6 ml de Neem por litro de agua. Además, de un testigo sin insecticida. Los adultos del CF se mantuvieron confinados con follaje de frambueso tratados con Neem durante cinco días y en postura por treinta días. Durante este periodo se determinó: cantidad de huevos, cantidad de larvas emergidas, porcentaje de larvas nacidas, grado de eficacia, dosis media efectiva (DE50) y dosis noventa efectiva (DE90). Los tratamientos con Neem fueron significativamente diferentes al testigo, presentando menor postura, menor emergencia de larvas y mayor grado de efectividad. Con 2 ml de Neem se obtuvo la menor postura; sin embargo, la dosis de 5 ml de Neem presentó la menor cantidad de larvas emergidas y el menor porcentaje de emergencia de larvas. La DE50 se determinó en 0,0290 ml de Neem y la DE90 en 8,923 ml de Neem por litro de agua. Con los antecedentes expuestos se concluyó que el Neem tiene un efecto que altera la postura y la embriogénesis del CF

Breaking the entangling gate speed limit for trapped-ion qubits using a phase-stable standing wave

All laser-driven entangling operations for trapped-ion qubits have hitherto been performed without control of the optical phase of the light field, which precludes independent tuning of the carrier and motional coupling. By placing $^{88}$Sr$^+$ ions in a $\lambda=674$ nm standing wave, whose relative position is controlled to $\approx\lambda/100$, we suppress the carrier coupling by a factor of $18$, while coherently enhancing the spin-motion coupling. We experimentally demonstrate that the off-resonant carrier coupling imposes a speed limit for conventional traveling-wave M{\o}lmer-S{\o}rensen gates; we use the standing wave to surpass this limit and achieve a gate duration of $15\ \mu$s, restricted by the available laser power.Comment: S. Saner and O. B\u{a}z\u{a}van contributed equally to this wor

First 230 GHz VLBI Fringes on 3C 279 using the APEX Telescope

We report about a 230 GHz very long baseline interferometry (VLBI) fringe finder observation of blazar 3C 279 with the APEX telescope in Chile, the phased submillimeter array (SMA), and the SMT of the Arizona Radio Observatory (ARO). We installed VLBI equipment and measured the APEX station position to 1 cm accuracy (1 sigma). We then observed 3C 279 on 2012 May 7 in a 5 hour 230 GHz VLBI track with baseline lengths of 2800 M$\lambda$ to 7200 M$\lambda$ and a finest fringe spacing of 28.6 micro-arcseconds. Fringes were detected on all baselines with SNRs of 12 to 55 in 420 s. The correlated flux density on the longest baseline was ~0.3 Jy/beam, out of a total flux density of 19.8 Jy. Visibility data suggest an emission region <38 uas in size, and at least two components, possibly polarized. We find a lower limit of the brightness temperature of the inner jet region of about 10^10 K. Lastly, we find an upper limit of 20% on the linear polarization fraction at a fringe spacing of ~38 uas. With APEX the angular resolution of 230 GHz VLBI improves to 28.6 uas. This allows one to resolve the last-photon ring around the Galactic Center black hole event horizon, expected to be 40 uas in diameter, and probe radio jet launching at unprecedented resolution, down to a few gravitational radii in galaxies like M 87. To probe the structure in the inner parsecs of 3C 279 in detail, follow-up observations with APEX and five other mm-VLBI stations have been conducted (March 2013) and are being analyzed.Comment: accepted for publication in A&

Device-Independent Quantum Key Distribution

Cryptographic key exchange protocols traditionally rely on computational conjectures such as the hardness of prime factorisation to provide security against eavesdropping attacks. Remarkably, quantum key distribution protocols like the one proposed by Bennett and Brassard provide information-theoretic security against such attacks, a much stronger form of security unreachable by classical means. However, quantum protocols realised so far are subject to a new class of attacks exploiting implementation defects in the physical devices involved, as demonstrated in numerous ingenious experiments. Following the pioneering work of Ekert proposing the use of entanglement to bound an adversary's information from Bell's theorem, we present here the experimental realisation of a complete quantum key distribution protocol immune to these vulnerabilities. We achieve this by combining theoretical developments on finite-statistics analysis, error correction, and privacy amplification, with an event-ready scheme enabling the rapid generation of high-fidelity entanglement between two trapped-ion qubits connected by an optical fibre link. The secrecy of our key is guaranteed device-independently: it is based on the validity of quantum theory, and certified by measurement statistics observed during the experiment. Our result shows that provably secure cryptography with real-world devices is possible, and paves the way for further quantum information applications based on the device-independence principle.Comment: 5+1 pages in main text and methods with 4 figures and 1 table; 37 pages of supplementary materia