The influence of environmental context on community composition in artificial rockpools associated with seawalls.

Artificial structures have become widespread features of coastal marine environments, and will likely proliferate further over the coming decades. These constitute new hard substrata in the marine environment which provide a fundamentally different habitat than natural shores. Eco-engineering solutions aim to ameliorate these differences by combining ecological knowledge and engineering criteria in the construction and modification of artificial substrata. Vertipools™ are artificial bolt-on rockpools intended for deployment on seawalls, where they have been shown to provide biodiversity benefits. In this study, a total of 32 Vertipools were retrofitted on eight seawalls in different environmental contexts (estuarine vs marine and urban vs rural) along the Irish Sea coastline, and were exposed to the environment for a period of two years. After two years, there were no differences in species richness, species-abundance distributions, diversity, or community composition between the specific environmental contexts examined here. Site-level variation was significant, and communities on Vertipools deployed in marine contexts were more variable in general than those in estuarine contexts. Community composition differed significantly between structural sections of the Vertipools, indicating that different sections provide specific microhabitats for colonisation. This study indicates that Vertipools provide biodiversity benefits in a variety of environmental contexts, and therefore are broadly viable as an eco-engineering solution.

Artificial rockpools: Seaweed colonisation and productivity vary between sites but are consistent across environmental contexts.

Artificial structures are widespread features of coastal environments, but are poor surrogates of natural rocky shores because they generally support depauperate assemblages with reduced population sizes. This has generated significant interest in eco-engineering solutions, including retrofitting seawalls with artificial rockpools to increase water retention and provide microhabitats. Although these have proven effective at individual sites, widespread uptake is contingent on evidence of consistent benefits across a range of contexts. In this study, Vertipools™ were retrofitted on eight seawalls in different environmental contexts (urban v rural and estuarine v marine) along the Irish Sea coastline and were monitored regularly for two years. Seaweed colonisation proceeded in a manner similar to patterns described for natural and artificial intertidal systems in general, consisting of early dominance by ephemeral species followed by the appearance and eventual establishment of perennial habitat-formers. After 24 months, species richness did not differ between contexts, but differed between sites. The units supported populations of large habitat-forming seaweeds at all sites. Productivity and community respiration of the colonising communities differed between sites by up to 0.5 mg O2 L-1 min-1, but not across environmental contexts. This study demonstrates that bolt-on rockpools attract similar levels of biotic colonisation and functioning in a variety of temperate environmental contexts, and could be considered for widespread implementation as an eco-engineering solution.

Dissecting the role of a large chromosomal inversion in life history divergence throughout the Mimulus guttatus species complex.

Chromosomal inversions can play an important role in adaptation, but the mechanism of their action in many natural populations remains unclear. An inversion could suppress recombination between locally beneficial alleles, thereby preventing maladaptive reshuffling with less-fit, migrant alleles. The recombination suppression hypothesis has gained much theoretical support but empirical tests are lacking. Here, we evaluated the evolutionary history and phenotypic effects of a chromosomal inversion which differentiates annual and perennial forms of Mimulus guttatus. We found that perennials likely possess the derived orientation of the inversion. In addition, this perennial orientation occurs in a second perennial species, M. decorus, where it is strongly associated with life history differences between co-occurring M. decorus and annual M. guttatus. One prediction of the recombination suppression hypothesis is that loci contributing to local adaptation will predate the inversion. To test whether the loci influencing perenniality pre-date this inversion, we mapped QTLs for life history traits that differ between annual M. guttatus and a more distantly related, collinear perennial species, M. tilingii. Consistent with the recombination suppression hypothesis, we found that this region is associated with life history in the absence of the inversion, and this association can be broken into at least two QTLs. However, the absolute phenotypic effect of the LG8 inversion region on life history is weaker in M. tilingii than in perennials which possess the inversion. Thus, while we find support for the recombination suppression hypothesis, the contribution of this inversion to life history divergence in this group is likely complex.

Speciation: On the Scent of Mate Discrimination Genes.

Animals use smell to recognize individuals from their own species and find suitable mates. A study of female chemical cues in two species of fruit flies uses a creative genetic strategy to identify an allele that is involved in species recognition and may play an important role in keeping these species apart in nature.

The impact of quality-reporting programs on hospital operations.

We used data from the 2005-06 Community Tracking Study site visits to examine the impact of quality reporting on hospitals' data collection and review processes, feedback and accountability mechanisms, quality improvement activities, and resource allocation. Individual hospitals participate in multiple, varied reporting programs with distinct effects on hospital operations. Reporting programs play complementary roles in encouraging quality improvement but are poorly coordinated and command sizable resources, in large part because of inadequate information technology. Policy should be directed at encouraging formal assessments of how individual and combinations of programs affect quality outcomes, and the development of adaptable information systems.

RNA structure analysis at single nucleotide resolution by selective 2'-hydroxyl acylation and primer extension (SHAPE).

The reactivity of an RNA ribose hydroxyl is shown to be exquisitely sensitive to local nucleotide flexibility because a conformationally constrained adjacent 3'-phosphodiester inhibits formation of the deprotonated, nucleophilic oxyanion form of the 2'-hydroxyl group. Reaction with an appropriate electrophile, N-methylisatoic anhydride, to form a 2'-O-adduct thus can be used to monitor local structure at every nucleotide in an RNA. We develop a quantitative approach involving Selective 2'-Hydroxyl Acylation analyzed by Primer Extension (SHAPE) to map the structure of and to distinguish fine differences in structure for tRNAAsp transcripts at single nucleotide resolution. Modest extensions of the SHAPE approach will allow RNA structure to be monitored comprehensively and at single nucleotide resolution for RNAs of arbitrary sequence and structural complexity and under diverse solution environments.

Can money buy quality? Physician response to pay for performance.

While pay for performance (P4P) has created a nationwide buzz among health plans, physicians and hospitals, most P4P initiatives are still on the drawing board, according to findings from the Center for Studying Health System Change's (HSC) 2005 site visits to 12 nationally representative communities. HSC focused on performance-based payment for physicians, finding that only two HSC communities-Orange County, Calif., and Boston-have significant physician P4P programs. In the other 10 communities, where almost no physicians have received quality-related payments to date, physician attitudes about P4P ranged from skeptical to hostile. P4P, a concept best suited to larger physician groups, may be difficult to implement in markets dominated by small physician practices. In spite of substantial barriers to initiating performance-related payment for physicians, most large health plans and Medicare are planning P4P programs.