New and Exciting in PLoS ONE

There are 21 new articles published tonight on PLoS ONE. As always, read, rate, comment, annotate, volunteer to do a Journal Club, and, if you blog about it, send trackbacks....Here are my picks:

A Televised, Web-Based Randomised Trial of an Herbal Remedy (Valerian) for Insomnia:

To combat the symptoms of insomnia, many people resort to non-prescribed herbal remedies such as valerian. In this randomised trial, the authors recruited 405 participants through a televised Norwegian health program and found only moderately beneficial effects of valerian on people with insomnia. However, the methods used to execute this trial suggest new ways of conducting research to evaluate the effects of health care interventions, and of improving public understanding and use of randomised trials.

Small-Scale Fisheries Bycatch Jeopardizes Endangered Pacific Loggerhead Turtles:

Industrial-scale fisheries are known to cause a decline in the number of large migratory animals through unintended catches. However the impact of smaller fisheries on these animals is poorly known. In this paper, Peckham and colleagues use satellite tracking data to monitor 30 North Pacific loggerhead turtles over a period of 10 years. Their results reveal that small-scale fisheries may be as detrimental to large migratory species as the larger industrial-scale fisheries.

Preventing Establishment: An Inventory of Introduced Plants in Puerto Villamil, Isabela Island, Galapagos:

As part of an island-wide project to identify and eradicate potentially invasive plant species before they become established, a program of inventories is being carried out in the urban and agricultural zones of the four inhabited islands in Galapagos. This study reports the results of the inventory from Puerto Villamil, a coastal village representing the urban zone of Isabela Island. We visited all 1193 village properties to record the presence of the introduced plants. In addition, information was collected from half of the properties to determine evidence for potential invasiveness of the plant species. We recorded 261 vascular taxa, 13 of which were new records for Galapagos. Most of the species were intentionally grown (cultivated) (73.3%) and used principally as ornamentals. The most frequent taxa we encountered were Cocos nucifera (coconut tree) (22.1%) as a cultivated plant and Paspalum vaginatum (salt water couch) (13.2%) as a non cultivated plant. In addition 39 taxa were naturalized. On the basis of the invasiveness study, we recommend five species for eradication (Abutilon dianthum, Datura inoxia, Datura metel, Senna alata and Solanum capsicoides), one species for hybridization studies (Opuntia ficus-indica) and three species for control (Furcraea hexapetala, Leucaena leucocephala and Paspalum vaginatum).

Identification and Classification of Hubs in Brain Networks:

Brain regions in the mammalian cerebral cortex are linked by a complex network of fiber bundles. These inter-regional networks have previously been analyzed in terms of their node degree, structural motif, path length and clustering coefficient distributions. In this paper we focus on the identification and classification of hub regions, which are thought to play pivotal roles in the coordination of information flow. We identify hubs and characterize their network contributions by examining motif fingerprints and centrality indices for all regions within the cerebral cortices of both the cat and the macaque. Motif fingerprints capture the statistics of local connection patterns, while measures of centrality identify regions that lie on many of the shortest paths between parts of the network. Within both cat and macaque networks, we find that a combination of degree, motif participation, betweenness centrality and closeness centrality allows for reliable identification of hub regions, many of which have previously been functionally classified as polysensory or multimodal. We then classify hubs as either provincial (intra-cluster) hubs or connector (inter-cluster) hubs, and proceed to show that lesioning hubs of each type from the network produces opposite effects on the small-world index. Our study presents an approach to the identification and classification of putative hub regions in brain networks on the basis of multiple network attributes and charts potential links between the structural embedding of such regions and their functional roles.

The Origins of Novel Protein Interactions during Animal Opsin Evolution:

Biologists are gaining an increased understanding of the genetic bases of phenotypic change during evolution. Nevertheless, the origins of phenotypes mediated by novel protein-protein interactions remain largely undocumented.

Here we analyze the evolution of opsin visual pigment proteins from the genomes of early branching animals, including a new class of opsins from Cnidaria. We combine these data with existing knowledge of the molecular basis of opsin function in a rigorous phylogenetic framework. We identify adaptive amino acid substitutions in duplicated opsin genes that correlate with a diversification of physiological pathways mediated by different protein-protein interactions.

This study documents how gene duplication events early in the history of animals followed by adaptive structural mutations increased organismal complexity by adding novel protein-protein interactions that underlie different physiological pathways. These pathways are central to vision and other photo-reactive phenotypes in most extant animals. Similar evolutionary processes may have been at work in generating other metazoan sensory systems and other physiological processes mediated by signal transduction.