Gravel pits support waterbird diversity in an urban landscape

We assessed the benefit of 11 gravel pits for the settlement of waterbird communities in an urbanized area lacking natural wetlands. Gravel pits captured 57% of the regional species pool of aquatic birds. We identified 39 species, among which five were regionally rare. We used the Self Organizing Map algorithm to calculate the probabilities of presence of species, and to bring out habitat conditions that predict assemblage patterns. The age of the pits did not correlate with assemblage composition and species richness. There was a positive influence of macrophyte cover on waterbird species richness. Larger pits did not support more species, but species richness increased with connectivity. As alternative wetland habitats, gravel pits are attractive to waterbirds, when they act as stepping stones that ensure connectivity between larger natural and/or artificial wetlands separated in space

Diversity of floral visitors to sympatric Lithophragma species differing in floral morphology

Most coevolving relationships between pairs of species are embedded in a broader multispecific interaction network. The mutualistic interaction between Lithophragma parviflorum (Saxifragaceae) and its pollinating floral parasite Greya politella (Lepidoptera, Prodoxidae) occurs in some communities as a pairwise set apart from most other interactions in those communities. In other communities, however, this pair of species occurs with congeners and with other floral visitors to Lithophragma. We analyzed local and geographic differences in the network formed by interactions between Lithophragma plants and Greya moths in communities containing two Lithophragma species, two Greya species, and floral visitors other than Greya that visit Lithophragma flowers. Our goal was to evaluate if non-Greya visitors were common, if visitor assembly differs between Lithophragma species and populations and if these visitors act as effective pollinators. Sympatric populations of L. heterophyllum and L. parviflorum differ in floral traits that may affect assemblies of floral visitors. Visitation rates by non-Greya floral visitors were low, and the asymptotic number of visitor species was less than 20 species in all populations. Lithophragma species shared some of the visitors, with visitor assemblages differing between sites more for L. heterophyllum than for L. parviflorum. Pollination efficacy experiments showed that most visitors were poor pollinators. Single visits to flowers by this assemblage of species resulted in significantly higher seed set in Lithophragma heterophyllum (30.6 ± 3.9 SE) than in L. parviflorum (4.7 ± 3.4 SE). This difference was consistent between sites, suggesting that these visitors provide a better fit to the floral morphology of L. heterophyllum. Overall, none of the non-Greya visitors appears to be either sufficiently common or efficient as a pollinator to impose strong selection on any of these four Lithophragma populations in comparison with Greya, which occurs within almost all populations of these species throughout their geographic ranges

The implications of “pay-for-performance” reimbursement for Otolaryngology – Head and Neck Surgery

Objective: To introduce otolaryngologists to outcomes-linked reimbursement ( pay-for-performance ), identify clinical practice implications and recommend changes for successful transition from the traditional pay-for-effort reimbursement model. Study design: Policy review Results: Payers are actively linking reimbursement to quality. Since the Institute of Medicine issued its report on medical errors in 1999, there has been much public and private concern over patient safety. In an effort to base health care payment on quality, pay-for-performance programs reward or penalize hospitals and physicians for their ability to maintain standards of care established by payers and regulatory groups. More than 100 such programs are operational in the United States today. This reimbursement model relies on detailed documentation in specific patient care areas to facilitate evaluation of outcomes for purposes of determining reimbursement. Since performance criteria for reimbursement have not yet been proposed within Otolaryngology-Head and Neck Surgery, otolaryngologists must be involved to ensure the adoption of reasonable goals and development of reasonable systems for documentation. Conclusion: Pay-for-performance reimbursement is increasingly common in the current era of outcomes-based medicine. It will assume an even greater role over the next 3 years and will directly affect most otolaryngologists

Endemic and epidemic dynamics of cholera: the role of the aquatic reservoir

BACKGROUND: In the last decades, attention to cholera epidemiology increased, as cholera epidemics became a worldwide health problem. Detailed investigation of V. cholerae interactions with its host and with other organisms in the environment suggests that cholera dynamics is much more complex than previously thought. Here, I formulate a mathematical model of cholera epidemiology that incorporates an environmental reservoir of V. cholerae. The objective is to explore the role of the aquatic reservoir on the persistence of endemic cholera as well as to define minimum conditions for the development of epidemic and endemic cholera. RESULTS: The reproduction rate of cholera in a community is defined by the product of social and environmental factors. The importance of the aquatic reservoir depends on the sanitary conditions of the community. Seasonal variations of contact rates force a cyclical pattern of cholera outbreaks, as observed in some cholera-endemic communities. CONCLUSIONS: Further development on cholera modeling requires a better understanding of V. cholerae ecology and epidemiology. We need estimates of the prevalence of V. cholerae infection in endemic populations as well as a better description of the relationship between dose and virulence

Geochemistry, faunal composition and trophic structure in reducing sediments on the southwest South Georgia margin

Despite a number of studies in areas of focused methane seepage, the extent of transitional sediments of more diffuse methane seepage, and their influence upon biological communities is poorly understood. We investigated an area of reducing sediments with elevated levels of methane on the South Georgia margin around 250 m depth and report data from a series of geochemical and biological analyses. Here, the geochemical signatures were consistent with weak methane seepage and the role of sub-surface methane consumption was clearly very important, preventing gas emissions into bottom waters. As a result, the contribution of methane-derived carbon to the microbial and metazoan food webs was very limited, although sulfur isotopic signatures indicated a wider range of dietary contributions than was apparent from carbon isotope ratios. Macrofaunal assemblages had high dominance and were indicative of reducing sediments, with many taxa common to other similar environments and no seep-endemic fauna, indicating transitional assemblages. Also similar to other cold seep areas, there were samples of authigenic carbonate, but rather than occurring as pavements or sedimentary concretions, these carbonates were restricted to patches on the shells of Axinulus antarcticus (Bivalvia, Thyasiridae), which is suggestive of microbe–metazoan interactions

Ground Dwelling Ants as Surrogates for Establishing Conservation Priorities in the Australian Wet Tropics

This study aims to identify a set of areas with high biodiversity value over a small spatial scale within the Australian Wet Tropics. We identified sites of high biodiversity value across an altitudinal gradient of ground dwelling ant communities using three measures of biodiversity. The three measures considered were estimated species richness, complementarity between sites and evolutionary history. The latter measure was derived using the systematic nomenclature of the ants to infer a surrogate phylogeny. The goal of conservation assessments could then be achieved by choosing the most diverse site combinations. This approach was found to be valuable for identifying the most diverse site combinations across an altitudinal gradient that could ensure the preservation of terrestrial ground dwelling invertebrates in the Australian Wet Tropics

Ground Dwelling Ants as Surrogates for Establishing Conservation Priorities in the Australian Wet Tropics

This study aims to identify a set of areas with high biodiversity value over a small spatial scale within the Australian Wet Tropics. We identified sites of high biodiversity value across an altitudinal gradient of ground dwelling ant communities using three measures of biodiversity. The three measures considered were estimated species richness, complementarity between sites and evolutionary history. The latter measure was derived using the systematic nomenclature of the ants to infer a surrogate phylogeny. The goal of conservation assessments could then be achieved by choosing the most diverse site combinations. This approach was found to be valuable for identifying the most diverse site combinations across an altitudinal gradient that could ensure the preservation of terrestrial ground dwelling invertebrates in the Australian Wet Tropics

Global Patterns of Guild Composition and Functional Diversity of Spiders

The objectives of this work are: (1) to define spider guilds for all extant families worldwide; (2) test if guilds defined at family level are good surrogates of species guilds; (3) compare the taxonomic and guild composition of spider assemblages from different parts of the world; (4) compare the taxonomic and functional diversity of spider assemblages and; (5) relate functional diversity with habitat structure. Data on foraging strategy, prey range, vertical stratification and circadian activity was collected for 108 families. Spider guilds were defined by hierarchical clustering. We searched for inconsistencies between family guild placement and the known guild of each species. Richness and abundance per guild before and after correcting guild placement were compared, as were the proportions of each guild and family between all possible pairs of sites. Functional diversity per site was calculated based on hierarchical clustering. Eight guilds were discriminated: (1) sensing, (2) sheet, (3) space, and (4) orb web weavers; (5) specialists; (6) ambush, (7) ground, and (8) other hunters. Sixteen percent of the species richness corresponding to 11% of all captured individuals was incorrectly attributed to a guild by family surrogacy; however, the correlation of uncorrected vs. corrected guilds was invariably high. The correlation of guild richness or abundances was generally higher than the correlation of family richness or abundances. Functional diversity was not always higher in the tropics than in temperate regions. Families may potentially serve as ecological surrogates for species. Different families may present similar roles in the ecosystems, with replacement of some taxa by other within the same guild. Spiders in tropical regions seem to have higher redundancy of functional roles and/or finer resource partitioning than in temperate regions. Although species and family diversity were higher in the tropics, functional diversity seems to be also influenced by altitude and habitat structure

Marine Macroalgal Diversity Assessment of Saba Bank, Netherlands Antilles

Background: Located in the Dutch Windward Islands, Saba Bank is a flat-topped seamount (20–45 m deep in the shallower regions). The primary goals of the survey were to improve knowledge of biodiversity for one of the world’s most significant, but little-known, seamounts and to increase basic data and analyses to promote the development of an improved management plan. Methodology/Principal Findings: Our team of three divers used scuba to collect algal samples to depths of 50 m at 17 dive sites. Over 360 macrophyte specimens (12 putative new species) were collected, more than 1,000 photographs were taken in truly exceptional habitats, and three astonishing new seaweed community types were discovered. These included: (1) ‘‘Field of Greens’ ’ (N 17u30.6209, W63u27.7079) dominated by green seaweeds as well as some filamentous reds, (2) ‘‘Brown Town’ ’ (N 17u28.0279, W63u14.9449) dominated by large brown algae, and (3) ‘‘Seaweed City’ ’ (N 17u26.4859, W63u16.8509) with a diversity of spectacular fleshy red algae. Conclusions/Significance: Dives to 30 m in the more two-dimensional interior habitats revealed particularly robust specimens of algae typical of shallower seagrass beds, but here in the total absence of any seagrasses (seagrasses generally do not grow below 20 m). Our preliminary estimate of the number of total seaweed species on Saba Bank ranges from a minimum of 150 to 200. Few filamentous and thin sheet forms indicative of stressed or physically disturbed environments were observed. A more precise number still awaits further microscopic and molecular examinations in the laboratory. The expedition, while intensive, has only scratched the surface of this unique submerged seamount/atoll