Robust strategies for lossy quantum interferometry

We give a simple multiround strategy that permits to beat the shot noise limit when performing interferometric measurements even in the presence of loss. In terms of the average photon number employed, our procedure can achieve twice the sensitivity of conventional interferometric ones in the noiseless case. In addition, it is more precise than the (recently proposed) optimal two-mode strategy even in the presence of loss.Comment: 4 pages, 3 figure

Deconstructing double-barred galaxies in 2D and 3D. II. Two distinct groups of inner bars

The intrinsic photometric properties of inner and outer stellar bars within 17 double-barred galaxies are thoroughly studied through a photometric analysis consisting of: i) two-dimensional multi-component photometric decompositions, and ii) three-dimensional statistical deprojections for measuring the thickening of bars, thus retrieving their 3D shape. The results are compared with previous measurements obtained with the widely used analysis of integrated light. Large-scale bars in single- and double-barred systems show similar sizes, and inner bars may be longer than outer bars in different galaxies. We find two distinct groups of inner bars attending to their in-plane length and ellipticity, resulting in a bimodal behaviour for the inner/outer bar length ratio. Such bimodality is related neither to the properties of the host galaxy nor the dominant bulge, and it does not show a counterpart in the dimension off the disc plane. The group of long inner bars lays at the lower end of the outer bar length vs. ellipticity correlation, whereas the short inner bars are out of that relation. We suggest that this behaviour could be due to either a different nature of the inner discs from which the inner bars are dynamically formed, or a different assembly stage for the inner bars. This last possibility would imply that the dynamical assembly of inner bars is a slow process taking several Gyr to happen. We have also explored whether all large-scale bars are prone to develop an inner bar at some stage of their lives, possibility we cannot fully confirm or discard.Comment: 14 pages, 8 figures, 1 table. Accepted for publication in MNRA

Theory of Weak Hypernuclear Decay

The weak nonmesonic decay of Lambda-hypernuclei is studied in the context of a one-meson-exchange model. Predictions are made for the decay rate, p/n stimulation ratio and the asymmetry in polarized hypernuclear decay.Comment: Standard 41 page Latex fil

Comparison between the Torquato-Rintoul theory of the interface effect in composite media and elementary results

We show that the interface effect on the properties of composite media recently proposed by Torquato and Rintoul (TR) [Phys. Rev. Lett. 75, 4067 (1995)] is in fact elementary, and follows directly from taking the limit in the dipolar polarizability of a coated sphere: the TR ``critical values'' are simply those that make the dipolar polarizability vanish. Furthermore, the new bounds developed by TR either coincide with the Clausius-Mossotti (CM) relation or provide poor estimates. Finally, we show that the new bounds of TR do not agree particularly well with the original experimental data that they quote.Comment: 13 pages, Revtex, 8 Postscript figure

Destination Online Communication: Why Less is Sometimes More. A Study of Online Communications of English Destinations

This research investigates the relationship between Web site design and the Web site end-user experience of a vast number of English tourism destinations, both local and regional ones. Following recent research in the field, this paper evaluates destinations' online communication based on the implemented Web site features and on the effectiveness of the communication itself, borrowing its research methodology from different domains. After content and functionality analysis, a user-experience, scenario-based investigation has been carried out, which demonstrated that complex Web sites do not always serve end-users' needs properly; in other words, Web site complexity is not directly related with good user experience. This research may help destination managers to foster their online communication if they have fewer content and functionalities but are better focused and clearly user-oriented. © 2014 Taylor & Francis

Isolation and characterization of oxidizedoligogalacturonides: meccanism of dampening of damps

Oligogalacturonides (OGs) released upon partial degradation of homogalacturonan, are a well-known class of Damage-Associated Molecular Patterns (DAMPs). Besides inducing immunity, OGs negatively affect plant growth by antagonizing auxin responses. Because the recognition of DAMPs poses the intrinsic risk of activating an exaggerated response that may impair plant survival, dampening mechanisms of DAMPs should exist. Transgenic Arabidopsis plants (OGM plants) expressing a chimeric protein called "OGmachine" accumulate oligogalacturonides (OGs) in their tissues and exhibit enhanced resistance to a variety of pathogens; however the growth of these plants is severely impaired. The prolonged release of OGs triggers defense responses that in the long term are deleterious for the plant. We used the OGM plants as a tool to investigate a possible regulatory mechanism by searching for elicitor-inactive OGs that may derive from elicitor-active OGs through an enzymatic modification. By analyzing the OGs produced in the transgenic plants, modified OGs were isolated. The nature of the modification was investigated by electrospray ionization mass spectrometry and resulted to be the oxidation to galactaric acid of the residue at the reducing end of OGs (oxOGs). OxOGs were tested for their ability to induce defense responses and antagonize auxin responses. In all experiments, they were inactive as compared to the corresponding typical OGs. We succeeded to isolate and characterize one of the enzymes that causes the inactivation of OGs: it is a FAD binding oxidase, that we named OGOX1, capable of producing elicitor-inactive oxidized OGs and H2O2

Long term fish assemblages as units of management in a temperate estuary (Rio de La Plata - SW Atlantic Ocean)

Demersal fish assemblages from trawl surveys in the Rio de la Plata estuary and its inner continental shelf were analyzed from 1975 to 1995. The first two factors of Principal Component Analysis explained 48% of the variance in species distribution, and they are consistent with the results of a cluster analysis. The analysis indicated the existence of three spatially and temporally distinct fish assemblages: internal and external estuarine and inner continental shelf (Uruguayan coastal assemblages). These assemblages were persistent considering the environmental characteristics and their species composition. Despite the changes registered in the species density during the period surveyed, the fish assemblages tend to persist over time. It was demonstrated that the assemblages can be considered as open systems and that there exists a reciprocal flow of organisms between adjacent associations. However, each assemblage showed high spatial and temporal persistence in accordance with the environmental characteristics of the system analyzed. Therefore, and according to the multispecies fisheries operating in the system, each assemblage defined could be considered a unit of management.Foram analisadas as associações dos peixes demersais provenientes de arrastos de prospecção no estuário do Rio de la Plata e sua plataforma interna no período de 1975 a 1995. Os dois primeiros fatores da Análise de Componentes Principais explicaram 48% da variância na distribuição das espécies sendo consistentes com os resultados da análise de agrupamento. Os resultados mostraram a existência de três associações de peixes espacial e temporalmente distintas: uruguaia costeira, estuarina externa e estuarina interna. Essas associações foram consistentes quanto às características ambientais e de composição de espécies. A despeito das mudanças registradas na densidade das espécies ao longo do período analisado, as associações de peixes foram persistentes ao longo do tempo. No presente trabalho foi demonstrado que embora as associações sejam consideradas um sistema aberto, um fluxo recíproco de organismos acontece entre associações adjacentes. Contudo, cada associação apresenta diferentes graus de estabilidade, dependentes da estabilidade física e temporal do habitat, e das interações das espécies nas associações. No entanto, cada associação mostrou alta persistência espacial e temporal, apesar da variabilidade ambiental no sistema analisado. Nesse sentido, e de acordo com a pesca multiespecífica que opera neste sistema, cada associação poderá ser considerada como uma unidade de gestão