Pilot see,pilot do: Examining the predictors of pilots’ risk management behaviour

Decision-making under uncertainty, known as risk management, is common in many professions including medicine and the military. Within general aviation, it is a skill that pilots are largely expected to acquire through experience. This study sought to determine if there are known markers (i.e., attitude and risk perception) and or personal characteristics (i.e., flight experience and age) that predict the acquisition and utilization of this skill. Fifty-six participants were presented with a risky flight which involved searching for a wayward parachutist with minimal fuel on board their aircraft. A clear distinction in terms of ‘risk perception’ was evident between those pilots who elected to undertake the risky flight (36 participants) and those pilots who did not (20 participants). There was also evidence of attitudinal and demographic differences between the two groups. The results have implications for the selection and training of pilots.     

Phytoremediation and long-term site management of soil contaminated with pentachlorophenol (PCP) and heavy metals

Pentachlorophenol (PCP) is a persistent organic pollutant (POP) previously used as a timber treatment chemical to prevent sap stain and wood rot. Commonly used in wood treatment industries for the last 50 years, there are now many sites worldwide that are contaminated with PCP. Although persistent, PCP is a mobile contaminant and therefore has a propensity to leach and contaminate surrounding environments. Both willow (Salix sp., 'Tangoio') and poplar (Populus sp. 'Kawa') growing in an open-ended plastic greenhouse were found to tolerate soil PCP concentrations of 250 mg kg(-1) or less and both species stimulated a significant increase in soil microbial activity when compared to unplanted controls. Both poplar and willow could not survive PCP concentrations above 250 mg kg(-1) in soil. Pentachlorophenol degradation occurred in both planted and unplanted pots, but a higher rate of degradation was observed in the planted pots. Soil contaminated by wood-treatment activities often contains co-contaminants such as B, Cr, Cu and As, that are also used as timber preservatives. An additional column leaching experiment, done along side the potted trial, found that PCP, B, Cr, Cu and As were all present in the column leachate. This indicates that although Cu, Cr and As are generally considered immobile in the soil, they were mobilised under our column conditions. If a contaminated site were to be hydraulically 'sealed' using plants, a reticulation irrigation system should be installed to capture any contaminant leachate resulting from heavy rains. This captured leachate can either be independently treated, or reapplied to the site. Our data demonstrate a reduction in soil hydraulic conductivity with repeated application of leachate containing PCP and metal compounds but the soil did not become anaerobic. This would need to be considered in site remediation design.     

A Daily Time Series Analysis of StreamWater Phosphorus Concentrations Along an Urban to Forest Gradient

During a 1-year period, we sampled stream water total phosphorus (TP) concentrations daily and soluble reactive phosphorus (SRP) concentrations weekly in four Seattle area streams spanning a gradient of forested to urban-dominated land cover. The objective of this study was to develop time series models describing stream water phosphorus concentration dependence on seasonal variation in stream base flows, short-term flow fluctuations, antecedent flow conditions, and rainfall. Stream water SRP concentrations varied on average by ±18% or ±5.7 μg/L from one week to another, whereas TP varied ±48% or ±32.5 μg/L from one week to another. On average, SRP constituted about 47% of TP. Stream water SRP concentrations followed a simple sine-wave annual cycle with high concentrations during the low-flow summer period and low concentrations during the high-flow winter period in three of the four study sites. These trends are probably due to seasonal variation in the relative contributions of groundwater and subsurface flows to stream flow. In forested Issaquah Creek, SRP concentrations were relatively constant throughout the year except during the fall, when a major salmon spawning run occurred in the stream and SRP concentrations increased markedly. Stream water SRP concentrations were statistically unrelated to short-term flow fluctuations, antecedent flow conditions, or rainfall in each of the study streams. Stream water TP concentrations are highly variable and strongly influenced by short-term flow fluctuations. Each of the processes assessed had statistically significant correlations with TP concentrations, with seasonal base flow being the strongest, followed by antecedent flow conditions, short-term flow fluctuations, and rainfall. Times series models for each individual stream were able to predict ∼70% of the variability in the SRP annual cycle in three of the four streams (r² = 0.57–0.81), whereas individual TP models explained ∼50% of the annual cycle in all streams (r² = 0.39–0.59). Overall, time series models for SRP and TP dynamics explained 82% and 76% of the variability for these variables, respectively. Our results indicate that SRP, the most biologically available and therefore most important phosphorus fraction, has simpler and easier-to-predict seasonal and weekly dynamics.     

Determining the optimum number of increments in composite sampling

Composite sampling can be more cost effective than simple random sampling. This paper considers how to determine the optimum number of increments to use in composite sampling. Composite sampling terminology and theory are outlined and a method is developed which accounts for different sources of variation in compositing and data analysis. This method is used to define and understand the process of determining the optimum number of increments that should be used in forming a composite. The blending variance is shown to have a smaller range of possible values than previously reported when estimating the number of increments in a composite sample. Accounting for differing levels of the blending variance significantly affects the estimated number of increments.

Ecomorphology and disease: cryptic effects of parasitism on host habitat use, thermoregulation, and predator avoidance

Parasites can cause dramatic changes in the phenotypes of their hosts, sometimes leading to a higher probability of predation and parasite transmission. Because an organism's morphology directly affects its locomotion, even subtle changes in key morphological traits may affect survival and behavior. However, despite the ubiquity of parasites in natural communities, few studies have incorporated parasites into ecomorphological research. Here, we evaluated the effects of parasite-induced changes in host phenotype on the habitat use, thermal biology, and simulated predator-escape ability of Pacific chorus frogs (Pseudacris regilla) in natural environments. Frogs with parasite-induced limb malformations were more likely to use ground microhabitats relative to vertical refugia and selected less-angled perches closer to the ground in comparison with normal frogs. Although both groups had similar levels of infection, malformed frogs used warmer microhabitats, which resulted in higher body temperatures. Likely as a result of their morphological abnormalities, malformed frogs allowed a simulated predator to approach closer before escaping and escaped shorter distances relative to normal frogs. These data indicate that parasite-induced morphological changes can significantly alter host behavior and habitat use, highlighting the importance of incorporating the ubiquitous, albeit cryptic, role of parasites into ecomorphological research.     

Dignity,face, and honor cultures: A study of negotiation strategy and outcomes in three cultures

This study compares negotiation strategy and outcomes in countries illustrating dignity, face, and honor cultures. Hypotheses predict cultural differences in negotiators' aspirations, use of strategy, and outcomes based on the implications of differences in self‐worth and social structures in dignity, face, and honor cultures. Data were from a face‐to‐face negotiation simulation; participants were intra‐cultural samples from the USA (dignity), China (face), and Qatar (honor). The empirical results provide strong evidence for the predictions concerning the reliance on more competitive negotiation strategies in honor and face cultures relative to dignity cultures in this context of negotiating a new business relationship. The study makes two important theoretical contributions. First, it proposes how and why people in a previously understudied part of the world, that is, the Middle East, use negotiation strategy. Second, it addresses a conundrum in the East Asian literature on negotiation: the theory and research that emphasize the norms of harmony and cooperation in social interaction versus empirical evidence that negotiations in East Asia are highly competitive. Copyright © 2016 John Wiley & Sons, Ltd.     

Global invasive potential of 10 parasitic witchweeds and related Orobanchaceae

The plant family Orobanchaceae includes many parasitic weeds that are also impressive invaders and aggressive crop pests with several specialized features (e.g. microscopic seeds, parasitic habits). Although they have provoked several large-scale eradication and control efforts, no global evaluation of their invasive potential is as yet available. We use tools from ecological niche modeling in combination with occurrence records from herbarium specimens to evaluate the global invasive potential of each of 10 species in this assemblage, representing several of the worst global invaders. The invasive potential of these species is considerable, with all tropical and subtropical countries, and most temperate countries, vulnerable to invasions by one or more of them.