Realization of manifolds as leaves using graph colorings

It is proved that any (repetitive) Riemannian manifold of bounded geometry can be realized as a leaf of some (minimal) Riemannian matchbox manifold without holonomy. Our methods can be adapted to achieve Cantor transversals or a prescribed holonomy covering, but then the manifold may not be realized as a dense leaf.Comment: 35 page

Environmental drivers of lesser weever stings on the northeast Atlantic coast (A Lanzada beach, Spain)

8 pages, 3 figures, 1 tableMany marine species, including anemones, snails, jellyfish, coral and fish, are venomous to humans, causing serious injuries or even death. Most of these animals live in warm, shallow waters, which increase the chances of an encounter with them. The majority of these interactions with humans are accidental; however, it is not well known under which circumstances (if any) these encounters are more likely to happen. A smart-city initiative was launched for A Lanzada beach (NW Spain) in the summer of 2014. As part of this initiative, lifeguards collated data on all incidents occurring on the beach, including the stings of Echiichthys vipera, the lesser weever. Additionally, a number of environmental parameters were monitored. Using this unique information, statistical models were developed to evaluate under which environmental conditions beach users would be more prone to be stung by lesser weevers. The optimal model showed that stings were more likely at the southern end of this 2.7 km long beach, pointing to differences in sediment composition along the beach as a key factor. Moreover, warmer seawater and higher air temperature increased the chances of being stung. Furthermore, stings increased at low tide and decreased under strong meridional wind conditions. Finally, the number of stings increased with beach occupation up to a levelling-off point. These outcomes suggest that a combination of fish behaviour and favourable climate conditions for beachgoers increases the chances of suffering an accidental encounter with E. vipera. Our results, based on basic environmental information, constitute a simple tool that could be used to provide precautionary advice to beach users to avoid accidental encounters with the lesser weeverPeer reviewe

Environmental characterizacion, demography and threatens for conservation of the population of Culcita macrocarpa C. Presl. in Lugo Province (NW Spain)

Se aportan datos sobre el biotopo y parámetrosdemográficos de la única población conocida hasta estemomento de Culcita macrocarpa C. Presl. en la Provincia deLugo (Galicia, NW España). Los individuos se distribuyen entres subpoblaciones de tamaño desigual (19, 21 y 1 plantas)que crecen entre los 460 y 500 m en ambientes sombríos allado de un curso de auga temporal que discurre por elinterior de un extenso robledal. En conjunto, la proporciónde individuos juveniles y adultos es muy semejante,mostrando los ejemplares una elevada vitalidad, aunquealgo más del 10% de sus frondes están afectadas por lapérdida de superficie fotosintética de origen desconocido.Actualmente no existen factores de amenaza evidentes,aunque la sustitución del bosque en el que se encuentra lapoblación estudiada por plantaciones de crecimiento rápidoo la intensificación del pastoreo podrían afectarnegativamente su conservación. Por esta razón, se proponela declaración de un Espacio Natural Protegido en la cuencadel Río Sor para asegurar la supervivencia de estapoblación de un helecho protegido por su condición deespecie amenazada de extinción.Data on biotope characteristics and demographyof the unique Culcita macrocarpa C. Presl. population knownin Lugo province (Galice, NW Spain) are presented. Theplants form three sub-populations with 19, 21 and 1individuals between 450 and 500 m a.s.l. and grow in ashady and wet biotope near a temporay stream that runsinto a wide common oak-dominated forest. Proportion ofadult and juvenile plants are similar and they show greatvitality in general. Nevertheless, almost 10% of the frondsshow a more or less severe loss of photosynthetic tissuecaused by an unkown agent. Nowadays there is nooutstanding threats that menace this population, butreplacement of native woodlands by rapid-growth speciesplantations or increase cattle preassure could affect in anegative way its future preservation. We suggest that thebetter action to ensure the preservation of the studiedpopulation of this endangered fern is to included the site intoa protected area for conservation