Subtidal macrozoobenthos communities from northern Chile during and post El Niño 1997–1998

Despite a large amount of climatic and oceanographic information dealing with the recurring climate phenomenon El Niño (EN) and its well known impact on diversity of marine benthic communities, most published data are rather descriptive and consequently our understanding of the underlying mechanisms and processes that drive community structure during EN are still very scarce. In this study, we address two questions on the effects of EN on macrozoobenthic communities: (1) how does EN affect species diversity of the communities in northern Chile? and (2) is EN a phenomenon that restarts community assembling processes by affecting species interactions in northern Chile? To answer these questions, we compared species diversity and co-occurrence patterns of soft-bottoms macrozoobenthos communities from the continental shelf off northern Chile during (March 1998) and after (September 1998) the strong EN event 1997–1998. The methods used varied from species diversity and species co-occurrence analyses to multivariate ordination methods. Our results indicate that EN positively affects diversity of macrozoobenthos communities in the study area, increasing the species richness and diversity and decreasing the species dominance. EN represents a strong disturbance that affects species interactions that rule the species assembling processes in shallow-water, sea-bottom environments

Enhanced electrochemical activity using vertically aligned carbon nanotube electrodes grown on carbon fiber

Vertically aligned carbon nanotubes were successfully grown on flexible carbon fibers by plasma enhanced chemical vapor deposition. The diameter of the CNT is controllable by adjusting the thickness of the catalyst Ni layer deposited on the fiber. Vertically aligned nanotubes were grown in a Plasma Enhanced Chemical Deposition system (PECVD) at a temperature of 630 ºC, d.c. bias of -600 V and 160 and 68 sccm flow of ammonia and acetylene, respectively. Using cyclic voltammetry measurements, an increase of the surface area of our electrodes, up to 50 times higher, was observed in our samples with CNT. The combination of VACNTs with flexible carbon fibers can have a significant impact on applications ranging from sensors to electrodes for fuel cells

Regional variations in occupancy frequency distribution patterns between odonate assemblages in Fennoscandia

Odonate (damselfly and dragonfly) species richness and species occupancy frequency distributions (SOFDs) were analyzed in relation to geographical location in standing waters (lakes and ponds) in Fennoscandia, from southern Sweden to central Finland. In total, 46 dragonfly and damselfly species were recorded from 292 waterbodies. Species richness decreased to the north and increased with waterbody area in central Finland, but not in southern Finland or in Sweden. Species occupancy ranged from 1 up to 209 lakes and ponds. Over 50% of the species occurred in <10% of the waterbodies, although this proportion decreased to the north. In the southern lakes and ponds, none of the species occurred in all lakes, whereas in the north, many species were present in all of the studied waterbodies. The dispersal ability of the species did not explain the observed species occupancy frequencies, but generalist species with a large geographical range occurred in a higher percentage of the waterbodies. At Fennoscandia scale, we found that the unimodal satellite pattern was predominant. However, at smaller scale, we found geographical variations in odonate species SOFD patterns. The most southern communities followed the unimodal satellite‐dominant pattern, whereas in other regions, communities fitted best with the bimodal core–satellite patterns. It seems that the richer species pool in the southern locations, and the larger distribution range of the northern species, skewed the unimodal pattern into a bimodal satellite‐dominant pattern.peerReviewe

Dispersal Reduction: Causes, Genomic Mechanisms, and Evolutionary Consequences

Recent biological analyses suggest that reductions in dispersal ability have beenkey drivers of diversification across numerous lineages. We synthesise emergingdata to highlight similarities regarding the causes and consequences of dispersalreduction across taxa and ecosystems, as well as the diverse genomic mechanismsunderpinning these shifts. Natural selection has acted on standing genetic variationwithin taxa to drive often rapid–and in some cases parallel–losses of dispersal,and ultimately speciation. Such shifts can thus represent an important nexus be-tween adaptive and neutral diversification processes, with substantial evolutionaryconsequences. Recognition of the links between these concepts that are emergingfrom differentfields, taxa and ecosystems is transforming our understanding of thefascinating role of dispersal reduction in the formation of biodiversity.J.M.W. and G.A.M. were supported by Marsden Fund contract UOO1412 (Royal Society of New Zealand). B.C.E. and P.A.B. were supported by Ministerio de Ciencia, Innovación, y Universidades (MICIU) grant CGL2017-85718-P (Agencia Estatal de Investigación/European Regional Development Fund).Peer reviewe