High activity and Levy searches : jellyfish can search the water column like fish

Over-fishing may lead to a decrease in fish abundance and a proliferation of jellyfish. Active movements and prey search might be thought to provide a competitive advantage for fish, but here we use data-loggers to show that the frequently occurring coastal jellyfish (Rhizostoma octopus) does not simply passively drift to encounter prey. Jellyfish (327 days of data from 25 jellyfish with depth collected every 1 min) showed very dynamic vertical movements, with their integrated vertical movement averaging 619.2 m d−1, more than 60 times the water depth where they were tagged. The majority of movement patterns were best approximated by exponential models describing normal random walks. However, jellyfish also showed switching behaviour from exponential patterns to patterns best fitted by a truncated Lévy distribution with exponents (mean μ = 1.96, range 1.2–2.9) close to the theoretical optimum for searching for sparse prey (μopt ≈ 2.0). Complex movements in these ‘simple’ animals may help jellyfish to compete effectively with fish for plankton prey, which may enhance their ability to increase in dominance in perturbed ocean systems

JeDI: Jellyfish Database Initiative

Global records on gelatinous zooplankton for the past 200 years.The Jellyfish Database Initiative (JeDI) is a scientifically-coordinated global database dedicated to gelatinous zooplankton (members of the Cnidaria, Ctenophora and Thaliacea) and associated environmental data. The database holds 476,000 quantitative, categorical, presence-absence and presence only records of gelatinous zooplankton spanning the past four centuries (1790-2011) assembled from a variety of published and unpublished sources. Gelatinous zooplankton data are reported to species level, where identified, but taxonomic information on phylum, family and order are reported for all records. Other auxiliary metadata, such as physical, environmental and biometric information relating to the gelatinous zooplankton metadata, are included with each respective entry. JeDI has been developed and designed as an open access research tool for the scientific community to quantitatively define the global baseline of gelatinous zooplankton populations and to describe long-term and large-scale trends in gelatinous zooplankton populations and blooms. It has also been constructed as a future repository of datasets, thus allowing retrospective analyses of the baseline and trends in global gelatinous zooplankton populations to be conducted in the future.This project was funded by the National Science Foundation Award OCE-103014

How genetically heterogeneous is Kabuki syndrome?:MLL2 testing in 116 patients, review and analyses of mutation and phenotypic spectrum

MLL2 mutations are detected in 55 to 80% of patients with Kabuki syndrome (KS). In 20 to 45% patients with KS, the genetic basis remains unknown, suggesting possible genetic heterogeneity. Here, we present the largest yet reported cohort of 116 patients with KS. We identified MLL2 variants in 74 patients, of which 47 are novel and a majority are truncating. We show that pathogenic missense mutations were commonly located in exon 48. We undertook a systematic facial KS morphology study of patients with KS at our regional dysmorphology meeting. Our data suggest that nearly all patients with typical KS facial features have pathogenic MLL2 mutations, although KS can be phenotypically variable. Furthermore, we show that MLL2 mutation-positive KS patients are more likely to have feeding problems, kidney anomalies, early breast bud development, joint dislocations and palatal malformations in comparison with MLL2 mutation-negative patients. Our work expands the mutation spectrum of MLL2 that may help in better understanding of this molecule, which is important in gene expression, epigenetic control of active chromatin states, embryonic development and cancer. Our analyses of the phenotype indicates that MLL2 mutation-positive and -negative patients differ systematically, and genetic heterogeneity of KS is not as extensive as previously suggested. Moreover, phenotypic variability of KS suggests that MLL2 testing should be considered even in atypical patients

Beyond Models and Metaphors: Complexity Theory, Systems Thinking and International Relations

The concepts, language and methods of complexity theory have been slowly making their way into international relations (IR), as scholars explore their potential for extending our understanding of the dynamics of international politics. In this article we examine the progress made so far and map the existing debates within IR that are liable to being significantly reconfigured by the conceptual resources of complexity. We consider the various ontological, epistemological and methodological questions raised by complexity theory and its attendant worldview. The article concludes that, beyond metaphor and computational models, the greatest promise of complexity is a reinvigoration of systems thinking that eschews the flaws and limitations of previous instantiations of systems theory and offers an array of conceptual tools apposite to analysing international politics in the twenty-first century