New and Exciting in PLoS this week

Article-Level Metrics and the Evolution of Scientific Impact:

Formally published papers that have been through a traditional prepublication peer review process remain the most important means of communicating science today. Researchers depend on them to learn about the latest advances in their fields and to report their own findings. The intentions of traditional peer review are certainly noble: to ensure methodological integrity and to comment on potential significance of experimental studies through examination by a panel of objective, expert colleagues. In principle, this system enables science to move forward on the collective confidence of previously published work. Unfortunately, the traditional system has inspired methods of measuring impact that are suboptimal for their intended uses.

The Unintended Consequences of Clinical Trials Regulations:

The experience of clinical researchers worldwide indicates that a major obstacle to undertaking academic research is the ever-increasing bureaucracy attached to the process. Recent changes in research governance were intended to ensure that clinical trials are safe and informative. However, the regulatory burden is now obstructing high quality science and has become the biggest single threat to research carried out in academia [1]. We illustrate here this international problem by reference to the regulations imposed by the European Union and the incorporation of these restrictions into UK national law concerning Good Clinical Practice (GCP).

Explaining the Linguistic Diversity of Sahul Using Population Models:

About one-fifth of all the world's languages are spoken in present day Australia, New Guinea, and the surrounding islands. This corresponds to the boundaries of the ancient continent of Sahul, which broke up due to rising sea levels about 9000 years before present. The distribution of languages in this region conveys information about its population history. The recent migration of the Austronesian speakers can be traced with precision, but the histories of the Papuan and Australian language speakers are considerably more difficult to reconstruct. The speakers of these languages are presumably descendants of the first migrations into Sahul, and their languages have been subject to many millennia of dispersal and contact. Due to the antiquity of these language families, there is insufficient lexical evidence to reconstruct their histories. Instead we use abstract structural features to infer population history, modeling language change as a result of both inheritance and horizontal diffusion. We use a Bayesian phylogenetic clustering method, originally developed for investigating genetic recombination to infer the contribution of different linguistic lineages to the current diversity of languages. The results show the underlying structure of the diversity of these languages, reflecting ancient dispersals, millennia of contact, and probable phylogenetic groups. The analysis identifies 10 ancestral language populations, some of which can be identified with previously known phylogenetic groups (language families or subgroups), and some of which have not previously been proposed.

The Evolution of a Capacity to Build Supra-Cellular Ropes Enabled Filamentous Cyanobacteria to Colonize Highly Erodible Substrates:

Several motile, filamentous cyanobacteria display the ability to self-assemble into tightly woven or twisted groups of filaments that form macroscopic yarns or ropes, and that are often centimeters long and 50-200 µm in diameter. Traditionally, this trait has been the basis for taxonomic definition of several genera, notably Microcoleus and Hydrocoleum, but the trait has not been associated with any plausible function. Through the use of phylogenetic reconstruction, we demonstrate that pedigreed, rope-building cyanobacteria from various habitats do not form a monophyletic group. This is consistent with the hypothesis that rope-building ability was fixed independently in several discrete clades, likely through processes of convergent evolution or lateral transfer. Because rope-building cyanobacteria share the ability to colonize geologically unstable sedimentary substrates, such as subtidal and intertidal marine sediments and non-vegetated soils, it is also likely that this supracellular differentiation capacity imparts a particular fitness advantage in such habitats. The physics of sediment and soil erosion in fact predict that threads in the 50-200 µm size range will attain optimal characteristics to stabilize such substrates on contact. Rope building is a supracellular morphological adaptation in filamentous cyanobacteria that allows them to colonize physically unstable sedimentary environments, and to act as successful pioneers in the biostabilization process.

The Link between Dengue Incidence and El Niño Southern Oscillation:

In a new study by Johansson and colleagues published in this issue of PLoS Medicine [12], the authors carry out statistical time-series analyses to examine the dynamic relationship between climate variables and the incidence of dengue in Thailand, Mexico, and Puerto Rico. They find no systematic association between multi-annual dengue outbreaks and El Niño Southern Oscillation.

Avian Host-Selection by Culex pipiens in Experimental Trials:

Evidence from field studies suggests that Culex pipiens, the primary mosquito vector of West Nile virus (WNV) in the northeastern and north central United States, feeds preferentially on American robins (Turdus migratorius). To determine the contribution of innate preferences to observed preference patterns in the field, we conducted host preference trials with a known number of adult female C. pipiens in outdoor cages comparing the relative attractiveness of American robins with two common sympatric bird species, European starling, Sternus vulgaris and house sparrow, Passer domesticus. Host seeking C. pipiens were three times more likely to enter robin-baited traps when with the alternate host was a European starling (n = 4 trials; OR = 3.06; CI [1.42-6.46]) and almost twice more likely when the alternative was a house sparrow (n = 8 trials; OR = 1.80; CI = [1.22-2.90]). There was no difference in the probability of trap entry when two robins were offered (n = 8 trials). Logistic regression analysis determined that the age, sex and weight of the birds, the date of the trial, starting-time, temperature, humidity, wind-speed and age of the mosquitoes had no effect on the probability of a choosing a robin over an alternate bird. Findings indicate that preferential feeding by C. pipiens mosquitoes on certain avian hosts is likely to be inherent, and we discuss the implications innate host preferences may have on enzootic WNV transmission.

How Can We Support the Use of Systematic Reviews in Policymaking?:

In the last few years the landscape has changed dramatically for policymakers seeking to use research evidence in the policymaking process. The landscape has also changed for the many stakeholders seeking to use research evidence to influence the policymaking process. The task once seemed overwhelming given the dearth of synthesized research evidence on the "big", typically multifaceted, questions that matter to policymakers and stakeholders [1],[2]. Now it isn't uncommon for these groups to find dozens of systematic reviews that address the governance, financial, and delivery arrangements within health systems that can determine whether a cost-effective program, service, or drug reaches those who need it. For example, teams of African policymakers, stakeholders, and researchers drew on 30 reviews for what at first glance seems a straightforward question: how to support the widespread use of artemisinin-based combination therapy (ACT) to treat uncomplicated falciparum malaria. The review of qualitative studies of people's views about and experiences with medicine sellers provided insights that were as central to the process as reviews of the effectiveness of a particular ACT formulation or the home-based management of malaria [3]-[5].