Examinando por Autor "Pons, Daniel J."
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Ítem Domestic dog and alien North American mink as reservoirs of infectious diseases in the endangered Southern river otter(Universidad Austral de Chile, 2022) Barros, Macarena; Pons, Daniel J.; Moreno, Andrea; Vianna, Juliana; Ramos, Barbara; Dueñas, Fernando; Coccia, Cristina; Saavedra-Rodríguez, Roberto; Santibañez, Alexis; Medina-Vogel, GonzaloIntroduced alien carnivores are host to infectious diseases that may become an important threat for native carnivore species conservation. Canine distemper virus (CDV) is thought to be transmitted among individuals by direct contact and to present viral dynamics associated with a density-dependent multi-host carnivore community. In contrast, Canine Parvovirus (CPV) is mostly transmitted by indirect contact and does not depend only on the density, but also on the social behaviour of infected as well as susceptible hosts. The objective of this study was to assess how introduced American mink (Neovison vison) can act as a bridge-host between domestic dog (Canis familiaris) and Southern river otter (Lontra provocax) in different dog and mink population density scenarios. Our data show that otters are seropositive to both CDV and PV, as well as a molecular identity to Parvovirus in dogs and minks. Furthermore, a strong positive correlation between dog population density and observed seroprevalence of CDV in dogs, minks, and otters was recorded. For Parvovirus, the observed seroprevalence in mink and otters was not correlated to a higher dog population density, but instead a relationship between dog and mink population densities and social behaviour. Our results suggest that introduced American mink and domestic dogs are reservoirs of CDV and PV, both being diseases of major importance for the conservation of native endangered carnivores in Patagonia. © 2022 Universidad Austral de Chile. All rights reserved.Ítem From hopf fibrations to exotic causal replacements(American Physical Society, 2016-10) Bezares, Miguel; Goulart, Érico; Palomera, Gonzalo; Pons, Daniel J.; Reyes, Enrique G.Topological solitons are relevant in several areas of physics. Recently, these configurations have been investigated in contexts as diverse as hydrodynamics, Bose-Einstein condensates, ferromagnetism, knotted light and non-Abelian gauge theories. In this paper we address the issue of wave propagation about a static Hopf soliton in the context of the Nicole model. Working within the geometrical optics limit, we show that several nontrivial lensing effects emerge due to nonlinear interactions as long as the theory remains hyperbolic. We conclude that similar effects are very likely to occur in effective field theories characterized by a topological invariant such as the Skyrme model of pions.Ítem Improving Trapping Efficiency for Control of American Mink (Neovison vison) in Patagonia(MDPI, 2022-01) Medina-Vogel, Gonzalo; Muñoz, Francisco; Moeggenberg, Meredith; Calvo-Mac, Carlos; Barros-Lama, Macarena; Ulloa, Nickolas; Pons, Daniel J.; Clapperton, B. KayTwo main challenges when controlling alien American mink (Neovison vison) in Patagonia are to maximize campaign efficacy and cost-effectiveness and to avoid trapping native species. We designed and tested new variants of collapsible wire box traps, compared the efficacy of a food-based bait and a scent lure and compared catch rates in different seasons of the year. We used the data to model the efficiency rate of the trapping and to determine the trapping effort required to remove 70–90% of the estimated discrete mink population. Between January 2018 and March 2021, we operated 59 trapping transects over 103 three-day trapping periods in southern Chile. Traps were first baited with canned fish, and afterwards with mink anal gland lure. We compared the efficacy of mink capture with that of our previous study. We trapped 196 mink (125 males, 71 females), with most captures in summer. The medium-sized GMV-18 trap caught more male mink, but the more compact GMV-13 caught fewer non-target rodents and no native mammals. The scent lure was more successful than the canned fish when the previous campaign’s data were included in the analysis. There was also a significant improvement in the proportion of female mink trapped and reduced labour compared with our previous campaign that used larger traps, fish bait and 400–500 m trap spacings. We caught relatively more females than males after the third night of trapping on a transect. Our data analysis supports the use of the GMV-13 variant of wire cage trap as the best trap size: it is effective on female mink, small, cheap and easy to transport. Combined with mink anal scent lure, it reduces the possibility of trapping native species compared with other traps tested in Chile. As the most efficient method for removing at least 70% of the estimated discrete mink population within the area covered by each trap transect in southern Chile tested to date, we recommend trapping campaigns using GMV-13 during summer, with a 200-m trap spacing, for up to 6 days before moving traps to a new site, with a combination of three days with a female scent gland lure, followed by three days with a male scent gland lure. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Variable exponent Sobolev spaces and regularity of domains-II(Springer-Verlag Italia s.r.l., 2023) Górka, Przemysław; Karak, Nijjwal; Pons, Daniel J.We provide necessary conditions on Euclidean domains for inclusions W1,p(·)(Ω) ↪ Lq(·)(Ω) of variable exponent Sobolev spaces. The conditions on the exponent p(·) are log-Hölder and log-log-Hölder continuity, while those on the domain Ω are the measure and the log measure density conditions. Restrictions on the exponents q(·) and p(·) appearing in Górka et al. (J. Geom. Anal. 310: 7304-7319, 2021) are relaxed, improving the results obtained in that work. © 2023, The Author(s).