Fusion11 Conference Summary

A summary account of the conference "Fusion11", held in Saint Malo, France, May 2-6, 2011.Comment: 10 pages, 13 figure

Plant functional constraints on foliar N:P ratios in a tropical forest landscape

Although large scale analyses of foliar N:P ratios suggest and overall pattern of P limitation in tropical forests, analyses within the biome are less indicative of a consistent pattern of nutrient limitation. High tree species diversity and soil heterogeneity are important factors driving the variability of foliar chemistry in the tropics; however, this variability could be reduced at the level of the functional characteristics of the species present at a site. In this study it is hypothesized that foliar N:P ratios would be more constrained when the species are grouped according to functional characteristics, and would reveal patterns of nutrient limitation. The study was conducted in a tropical forest landscape of the Porce region in Colombia, which consists of patches of primary and secondary forests of different ages. The functional groupings revealed consistent patterns of conservative N cycling in species present at young secondary sites, as well as conservative P cycling of the species present later in succession and in primary forests. Although the observed data have limitations in terms of capturing the overall variability for each functional group, the classification used here provided support for the proposed hypotheses. It is concluded that functional composition, rather than taxonomic composition, can potentially improve our understanding of nutrient cycling in tropical forests

Small clique number graphs with three trivial critical ideals

The critical ideals of a graph are the determinantal ideals of the generalized Laplacian matrix associated to a graph. In this article we provide a set of minimal forbidden graphs for the set of graphs with at most three trivial critical ideals. Then we use these forbidden graphs to characterize the graphs with at most three trivial critical ideals and clique number equal to 2 and 3.Comment: 33 pages, 3 figure

Theory summary. Hard Probes 2012

I provide a summary of the theoretical talks in Hard Probes 2012 together with some personal thoughts about the present and the future of the field.Comment: 8 pages. Proceedings of the conference Hard Probes 2012 - Sardinia - Italy - May 27 -June 1 2012 --- Comments welcom

Updating the bathymetry of the Maltese Islands : a national-scale marine survey employing interferometric sonar

Chapter 8The ERDF project detailed a requirment for the scanning of an extensive area of 415 square kilometers employing an interferometric sonar. The process, though hampered by high wind and adverse sea conditions was completed as per contract requirements, yielding interesting new information of the bathymetric landscapes of the Maltese Islands. Survey design: The campaign for the bathymetric survey of the Maltese islands, carried out during the summers of 2012 and 2013, summed total area of about 415 square kilometres and covered depths between 15 and 200 m. Th e total survey area was divided into 28 survey blocks, laid out so each one was completed during a full day of work. This rule applied to all the blocks except for blocks 16 and 17 which were completed over the course of two days each. Each survey block was completed by running survey lines parallel to the blocks’ longitudinal axis. During rough weather, lines were run parallel to predominant wave direction to minimise vessel roll. Line spacing ranged from 50 to 300 metres and was decided by a combination of the sensor’s accuracy at increasing horizontal range, depth, seabed type and sea state. Crosslines were also run for each block, usually on the boundary, to allow for additional data checks between neighbouring blockspeer-reviewe