Quasars Clustering at z approx 3 on Scales less sim 10 h^{-1} Mpc

We test the hypothesis whether high redshift QSOs would preferentially appear in small groups or pairs, and if they are associated with massive, young clusters. We carried out a photometric search for \Ly emitters on scales $\lesssim 10 h^{-1}$ Mpc, in the fields of a sample of 47 $z\approx3$ known QSOs. Wide and narrow band filter color-magnitude diagrams were generated for each of the $6'.6\times6'.6$ fields. A total of 13 non resolved objects with a significant color excess were detected as QSO candidates at a redshift similar to that of the target. All the candidates are significantly fainter than the reference QSOs, with only 2 of them within 2 magnitudes of the central object. Follow-up spectroscopic observations have shown that 5, i.e., about 40% of the candidates, are QSOs at the same redshift of the target; 4 are QSOs at different z (two of them probably being a lensed pair at z = 1.47); 2 candidates are unresolved HII galaxies at z$\sim$0.3; one unclassified and one candidate turned out to be a CCD flaw. These data indicate that at least 10% of the QSOs at z$\sim$3 do have companions. We have also detected a number of resolved, rather bright \Ly Emitter Candidates. Most probably a large fraction of them might be bright galaxies with [OII] emission, at z$\approx$ 0.3. The fainter population of our candidates corresponds to the current expectations. Thus, there are no strong indication for the existence of an overdensity of \Ly galaxies brighter than m $\approx$ 25 around QSOs at $z\approx$ 3.Comment: 29 pages, 8 figures, tar gzip LaTex file, accepted to appear in Ap

The Socio-Environmental Survey: a tool for an integrated study of protected areas. The case of Sierra Sur de Sevilla and Sierra de Cádiz

La declaración de Espacios Naturales Protegidos ha producido con frecuencia conflictos con las poblaciones locales en la gestión de la conservación de la naturaleza. En respuesta a esta realidad han surgido nuevos métodos y estrategias que buscan una mejor integración de la componente social en las áreas protegidas. Este artículo presenta los resultados de una Encuesta Socio-Ambiental (ESA) realizada durante la elaboración de una propuesta de Espacio Natural Protegido para la Red de Espacios Naturales Protegidos de Andalucía en la campiña agrícola del Subbético, entre las provincias de Sevilla y Cádiz (sur de España). A partir de los datos obtenidos se propone y discute la aplicación de la figura de Paisaje Protegido (tipo Categoría V de UICN) asociada a un modelo de gestión participativa abierta.The declaration of Protected Areas has frequently led to conflicts with local populations because of nature conservation management. In response to this reality new methods and strategies are emerging that are looking for a better integration of the social component in Protected Areas. This article shows the results of a Socio-Environmental Survey (SES) conducted during the elaboration of a Protected Area proposal for the Andalusian Protected Areas Network in the Subbetic agricultural “campiña”, between Seville and Cádiz provinces (Southern Spain). Based on the data obtained, the application of the Protected Landscape figure (type Category V of IUCN) associated to an open participatory management model is proposed and discussed

Does deterministic coexistence theory matter in a finite world?

Contemporary studies of species coexistence are underpinned by deterministic models that assume that competing species have continuous (i.e., noninteger) densities, live in infinitely large landscapes, and coexist over infinite time horizons. By contrast, in nature, species are composed of discrete individuals subject to demographic stochasticity and occur in habitats of finite size where extinctions occur in finite time. One consequence of these discrepancies is that metrics of species' coexistence derived from deterministic theory may be unreliable predictors of the duration of species coexistence in nature. These coexistence metrics include invasion growth rates and niche and fitness differences, which are now commonly applied in theoretical and empirical studies of species coexistence. In this study, we tested the efficacy of deterministic coexistence metrics on the duration of species coexistence in a finite world. We introduce new theoretical and computational methods to estimate coexistence times in stochastic counterparts of classic deterministic models of competition. Importantly, we parameterized this model using experimental field data for 90 pairwise combinations of 18 species of annual plants, allowing us to derive biologically informed estimates of coexistence times for a natural system. Strikingly, we found that for species expected to deterministically coexist, community sizes containing only 10 individuals had predicted coexistence times of more than 1000 years. We also found that invasion growth rates explained 60% of the variation in intrinsic coexistence times, reinforcing their general usefulness in studies of coexistence. However, only by integrating information on both invasion growth rates and species' equilibrium population sizes could most (>99%) of the variation in species coexistence times be explained. This integration was achieved with demographically uncoupled single-species models solely determined by the invasion growth rates and equilibrium population sizes. Moreover, because of a complex relationship between niche overlap/fitness differences and equilibrium population sizes, increasing niche overlap and increasing fitness differences did not always result in decreasing coexistence times, as deterministic theory would predict. Nevertheless, our results tend to support the informed use of deterministic theory for understanding the duration of species' coexistence while highlighting the need to incorporate information on species' equilibrium population sizes in addition to invasion growth rates

Identifying "Useful" Fitness Models: Balancing the Benefits of Added Complexity with Realistic Data Requirements in Models of Individual Plant Fitness

Direct species interactions are commonly included in individual fitness models used for coexistence and local diversity modeling. Though widely considered important for such models, direct interactions alone are often insufficient for accurately predicting fitness, coexistence, or diversity outcomes. Incorporating higher-order interactions (HOIs) can lead to more accurate individual fitness models but also adds many model terms, which can quickly result in model overfitting. We explore approaches for balancing the trade-off between tractability and model accuracy that occurs when HOIs are added to individual fitness models. To do this, we compare models parameterized with data from annual plant communities in Australia and Spain, varying in the extent of information included about the focal and neighbor species. The best-performing models for both data sets were those that grouped neighbors based on origin status and life form, a grouping approach that reduced the number of model parameters substantially while retaining important ecological information about direct interactions and HOIs. Results suggest that the specific identity of focal or neighbor species is not necessary for building well-performing fitness models that include HOIs. In fact, grouping neighbors by even basic functional information seems sufficient to maximize model accuracy, an important outcome for the practical use of HOI-inclusive fitness models

Intertwining symmetry algebras of quantum superintegrable systems on the hyperboloid

A class of quantum superintegrable Hamiltonians defined on a two-dimensional hyperboloid is considered together with a set of intertwining operators connecting them. It is shown that such intertwining operators close a su(2,1) Lie algebra and determine the Hamiltonians through the Casimir operators. By means of discrete symmetries a broader set of operators is obtained closing a so(4,2) algebra. The physical states corresponding to the discrete spectrum of bound states as well as the degeneration are characterized in terms of unitary representations of su(2,1) and so(4,2).Comment: 11 pages, 5 figure

La Encuesta Socio Ambiental: instrumento para el estudio integrado de espacios naturales protegidos. Aplicación a la Sierra Sur de Sevilla y Sierra de Cádiz

The declaration of Protected Areas has frequently led to conflicts with local populations because of nature conservation management. In response to this reality new methods and strategies are emerging that are looking for a better integration of the social component in Protected Areas. This article shows the results of a Socio-Environmental Survey (SES) conducted during the elaboration of a Protected Area proposal for the Andalusian Protected Areas Network in the Subbetic agricultural “campiña”, between Seville and Cádiz provinces (Southern Spain). Based on the data obtained, the application of the Protected Landscape figure (type Category V of IUCN) associated to an open participatory management model is proposed and discussed.La declaración de Espacios Naturales Protegidos ha producido con frecuencia conflictos con las poblaciones locales en la gestión de la conservación de la naturaleza. En respuesta a esta realidad han surgido nuevos métodos y estrategias que buscan una mejor integración de la componente social en las áreas protegidas. Este artículo presenta los resultados de una Encuesta Socio-Ambiental (ESA) realizada durante la elaboración de una propuesta de Espacio Natural Protegido para la Red de Espacios Naturales Protegidos de Andalucía en la campiña agrícola del Subbético, entre las provincias de Sevilla y Cádiz (sur de España). A partir de los datos obtenidos se propone y discute la aplicación de la figura de Paisaje Protegido (tipo Categoría V de UICN) asociada a un modelo de gestión participativa abierta

Optical Spectroscopy of nearby type1-LINERs

We present the highlights from our recent study of 22 local (z$<$0.025) type-1 LINERs from the Palomar Survey, on the basis of optical long-slit spectroscopic observations taken with TWIN/CAHA, ALFOSC/NOT and HST/STIS (Cazzoli et al. 2018). Our goals were threefold: (a) explore the AGN- nature of these LINERs by studying the broad (BLR-originated) H$\alpha$ component; (b) derive a reliable interpretation for the multiple narrow components of emission lines by studying their kinematics and ionisation mechanism (via standard BPTs); (c) probe the neutral gas in the nuclei of these LINERs for the first time. Hence, kinematics and fluxes of a set of emission lines, from H$\beta$ to [SII], and the NaD doublet in absorption have been modelled and measured, after the subtraction of the underlying light from the stellar component.Comment: Proceedings of the IAU Symposium 356, 'Nuclear activity in galaxies across cosmic time'. Based on Cazzoli et al. 2018, MNRAS, 480, 1106 available at https://academic.oup.com/mnras/article/480/1/1106/505038