Prospective spatial prediction of infectious disease: experience of New York State (USA) with West Nile Virus and proposed directions for improved surveillance

Infectious disease surveillance has become an international top priority due to the perceived risk of bioterrorism. This is driving the improvement of real-time geo-spatial surveillance systems for monitoring disease indicators, which is expected to have many benefits beyond detecting a bioterror event. West Nile Virus surveillance in New York State (USA) is highlighted as a working system that uses dead American Crows (Corvus brachyrhynchos) to prospectively indicate viral activity prior to human onset. A cross-disciplinary review is then presented to argue that this system, and infectious disease surveillance in general, can be improved by complementing spatial cluster detection of an outcome variable with predictive “risk mapping” that incorporates spatiotemporal data on the environment, climate and human population through the flexible class of generalized linear mixed models.

Using decomposition rates to infer how far back tree populations can be reconstructed

To study forest dynamics without relying on the space-for-time substitution, one must be able to follow a population or stand of trees back or forward in time. The method of stand reconstruction looks back in time by aging all the live trees and aging and dating the time of death of dead standing and fallen trees. However, dead trees are lost by decomposition so the record becomes increasingly incomplete with passage of time. Here we present a model of the passage of trees from dead standing to dead decomposed but still datable to completely decomposed and thus undatable or lost. We then generalize a method for calculating the falling rate of dead trees originally proposed in 1985 by A. P. Gore, E. A. Johnson, and H. P. Lo. We do this by removing the assumption that no trees are lost by decomposition, i.e., by using the decomposition rate. Finally, in the most important result, the model allows estimation of how far back a good estimate of the numbers in the population can be made if the decomposition rates are known.     

Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study

This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological–physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.     

Growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu, China

Three treatments, sediment plus lake water (S+W), sterilized sediment plus lake water (SS+W), and sediment plus filtered lake water (S+FW), were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment. The results showed that in the water column, biomass of all algae increased in all treatments when recruitment was initiated, whereas this tendency differed among treatments with further increment of temperature. The process of algal growth consisted of two stages: Stage I, the onset of recruitment and Stage II, the subsequent growth of algae. Compared with S+W, in Stage I, SS+W significantly increased the biomass of cyanophytes by 178.70%, and decreased the biomass of non-cyanophytes by 43.40%; In Stage II, SS+W notably stimulated the growth of all algae, thus incurring the occurrence of phytoplankton bloom. Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS+W, which resulted from the releasing of nutrients from sediment. These results suggest that algal growth in Stage II and algal inocula in the water column can be important factors for the formation of phytoplankton bloom. In addition, possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.     

A within‐individual study of interpersonal conflict as a work stressor: Dispositional and situational moderators

Focusing on interpersonal conflict as a work stressor, the authors used a within‐subjects research design to examine the effect of conflict episodes on employees' negative affect on the job. The roles of agreeableness and social support in moderating the negative effects of conflict episodes were also examined. A two‐week experience‐sampling study revealed that interpersonal conflict influenced employees' intraindividual fluctuations in negative affect. As predicted, agreeableness and social support influenced individuals' patterns of affective responses to conflict, such that conflict was more strongly associated with negative affect for agreeable employees, and for those with lower levels of social support at work. Overall, the results suggest that both personality (agreeableness) and context (social support) significantly moderate the affective implications of interpersonal conflict at work. Copyright © 2010 John Wiley & Sons, Ltd.     

A binational, supply-side evaluation for managing water quality and invasive fouling species on California's coastal boats

Integrated solutions are needed for sustainable management of risks posed by recreational boats to coastal water quality and ecosystems. Fouling organisms roughen vessel hull surfaces, creating friction that slows sailboats and increases fuel consumption by powerboats. Hull fouling control strategies for recreational boats that are stored in the water may include antifouling hull paints, newer alternative hull coatings, periodic in-water hull cleaning, and excluding propagules by surrounding the boat with a slip liner or raising it above water on a lift. Copper discharged to harbor waters from antifouling paints via passive leaching and in-water hull cleaning may elevate dissolved copper levels above government standards. Invasive species carried among boat-hull fouling organisms may be introduced as boats move among coastal areas. Some of these species tolerate copper in antifouling paints and copper-polluted harbor waters. Policy development must consider supply-side capacity, as well as economic and environmental sustainability, in managing these issues. This paper presents a supply-side evaluation useful in developing policies to co-manage water quality and invasive species risks for recreational boats navigating along the coasts of California, the Baja California peninsula and California's Sacramento-San Joaquin Delta. Supply-side perspectives on services, materials, costs, and boat owner behaviors, such as residence and travel patterns, awareness of hull-coating choices and selection of hull coatings, are determined. Analyses include evaluation of risks, risk management capacity and costs, and role of education in risk management. The issues raised are broadly applicable, as they are appearing on research and policy agendas in diverse coastal areas.     

Learning and adaptation in the management of waterfowl harvests

A formal framework for the adaptive management of waterfowl harvests was adopted by the U.S. Fish and Wildlife Service in 1995. The process admits competing models of waterfowl population dynamics and harvest impacts, and relies on model averaging to compute optimal strategies for regulating harvest. Model weights, reflecting the relative ability of the alternative models to predict changes in population size, are used in the model averaging and are updated each year based on a comparison of model predictions and observations of population size. Since its inception the adaptive harvest program has focused principally on mallards (Anas platyrhynchos), which constitute a large portion of the U.S. waterfowl harvest. Four competing models, derived from a combination of two survival and two reproductive hypotheses, were originally assigned equal weights. In the last year of available information (2007), model weights favored the weakly density-dependent reproductive hypothesis over the strongly density-dependent one, and the additive mortality hypothesis over the compensatory one. The change in model weights led to a more conservative harvesting policy than what was in effect in the early years of the program. Adaptive harvest management has been successful in many ways, but nonetheless has exposed the difficulties in defining management objectives, in predicting and regulating harvests, and in coping with the tradeoffs inherent in managing multiple waterfowl stocks exposed to a common harvest. The key challenge now facing managers is whether adaptive harvest management as an institution can be sufficiently adaptive, and whether the knowledge and experience gained from the process can be reflected in higher-level policy decisions.     

Trends in Pesticide Concentrations in Streamsof the Western United States, 1993‐20051

Johnson, Henry M., Joseph L. Domagalski, and Dina K. Saleh, 2010. Trends in Pesticide Concentrations in Streams of the Western United States, 1993‐2005. Journal of the American Water Resources Association (JAWRA) 00(0):1‐22. DOI: 10.1111/j.1752‐1688.2010.00507.x Abstract: Trends in pesticide concentrations for 15 streams in California, Oregon, Washington, and Idaho were determined for the organophosphate insecticides chlorpyrifos and diazinon and the herbicides atrazine, s‐ethyl diproplythiocarbamate (EPTC), metolachlor, simazine, and trifluralin. A parametric regression model was used to account for flow, seasonality, and antecedent hydrologic conditions and thereby estimate trends in pesticide concentrations in streams arising from changes in use amount and application method in their associated catchments. Decreasing trends most often were observed for diazinon, and reflect the shift to alternative pesticides by farmers, commercial applicators, and homeowners because of use restrictions and product cancelation. Consistent trends were observed for several herbicides, including upward trends in simazine at urban‐influenced sites from 2000 to 2005, and downward trends in atrazine and EPTC at agricultural sites from the mid‐1990s to 2005. The model provided additional information about pesticide occurrence and transport in the modeled streams. Two examples are presented and briefly discussed: (1) timing of peak concentrations for individual compounds varied greatly across this geographic gradient because of different application periods and the effects of local rain patterns, irrigation, and soil drainage and (2) reconstructions of continuous diazinon concentrations at sites in California are used to evaluate compliance with total maximum daily load targets.     

Genetic structure of the southeastern United States loggerhead turtle nesting aggregation: evidence of additional structure within the peninsular Florida recovery unit

The southeastern United States supports one of two large loggerhead turtle (Caretta caretta) nesting aggregations worldwide and is therefore critical to global conservation and recovery efforts for the species. Previous studies have established the presence of four demographically distinct nesting populations (management units) corresponding to beaches from (1) North Carolina through northeastern Florida, (2) peninsular Florida, (3) the Dry Tortugas, and (4) northwest Florida. Temporal and geographic genetic structure of the nesting aggregation was examined utilizing partial mitochondrial control region haplotype frequencies from 834 samples collected over the 2002 through 2008 nesting seasons from 19 beaches as well as previously published haplotype data. Most rookeries did not exhibit interannual genetic variation. However, the interannual variation detected did significantly impact the interpretation of spatial genetic structure in northeastern Florida. Based on pairwise F _ST comparisons, exact tests of population differentiation, and analysis of molecular variance, the present study upholds the distinctiveness of the four currently recognized management units and further supports recognition of discrete central eastern, southern (southeastern and southwestern), and central western Florida management units. Further subdivision may be warranted, but more intensive genetic sampling is required. In addition, tools such as telemetry and mark-recapture are needed to complement genetic data and overcome limitations of genetic markers in resolving loggerhead turtle rookery connectivity in the southeastern USA.     

Subpopulation structure of caribou (Rangifer tarandus L.) in arctic and subarctic Canada

Effective management and conservation of species, subspecies, or ecotypes require an understanding of how populations are structured in space. We used satellite-tracking locations and hierarchical and fuzzy clustering to quantify subpopulations within the behaviorally different barren-ground caribou (Rangifer tarandus groenlandicus), Dolphin and Union island caribou (R. t. groenlandicus x pearyi), and boreal (R. t. caribou) caribou ecotypes in the Northwest Territories and Nunavut, Canada. Using a novel approach, we verified that the previously recognized Cape Bathurst, Bluenose-West, Bluenose-East, Bathurst, Beverly, Qamanirjuaq, and Lorillard barren-ground subpopulations were robust and that the Queen Maude Gulf and Wager Bay barren-ground subpopulations were organized as individuals. Dolphin and Union island and boreal caribou formed one and two distinct subpopulation, respectively, and were organized as individuals. Robust subpopulations were structured by strong annual spatial affiliation among females; subpopulations organized as individuals were structured by migratory connectivity, barriers to movement, and/or habitat discontinuity. One barren-ground subpopulation used two calving grounds, and one calving ground was used by two barren-ground subpopulations, indicating that these caribou cannot be reliably assigned to subpopulations solely by calving-ground use. They should be classified by annual spatial affiliation among females. Annual-range size and path lengths varied significantly among ecotypes, including mountain woodland caribou (R. t. caribou), and reflected behavioral differences. An east-west cline in annual-range sizes and path lengths among migratory barren-ground subpopulations likely reflected differences in subpopulation size and habitat conditions and further supported the subpopulation structure identified.