Tomato journeys from farm to fruit shop

Popular calls to buy products with fewer embodied greenhouse gas (GHG) emissions belie the complexity involved in providing accurate information necessary for such consumer decisions to be effective. This study follows greenhouse-grown tomatoes from Australian farms to fruit shops in Sydney, Australia and investigates practicalities of accounting for GHG emissions in this fresh food chain. Data came from semi-structured interviews with farmers, wholesalers who operate at the (wholesale) Sydney Markets and retailers. GHG emissions were estimated using quantitative methodologies including Australian National Greenhouse Account Factors. A qualitative analysis of stakeholder views and knowledge was also conducted. Conclusions include that, per unit of tomatoes, on-farm GHG emissions appear far greater than those from fuel used for transport to Sydney Markets, and from wholesale or retail activities. Food mile or more comprehensive carbon labelling would probably not be practical for this supply chain. Factors likely to affect potential change among higher emitting participants are costs and availability of lower GHG-emitting practices. Mixed-method studies help identify parts of a chain to target emission reduction efforts.     

Migration,markets, and mangrove resource use on Kosrae,Federated States of Micronesia

Kosrae, Federated States of Micronesia, is a prototype of an island economy prone to economic crowding. Average family size is large, the habitable land area is small, economic activity is limited, and household dependence on natural resources for fuel and food is high. We analyze how economic crowding--and its mitigation through trade and migration policies--affects mangrove resource use. A comparison of household survey data from 1996 and 2000 indicates that despite decreases in US aid and public-sector jobs, average household consumption of mangrove resources has not increased. Migration and remittances have allowed the purchase of imported fuel and building materials substituting for mangrove wood. Despite changing preferences and shifts toward import consumption, population growth and further declines in US financial support will likely cause aggregate demand for mangrove and upland wood to rise. Moreover, continued emigration may accelerate the export of mangrove crabs to off-island Kosraeans.     

"Mobbing" in Hawaiian Monk Seals (Monachus schauinslani): The Value of Simulation Modeling in the Absence of Apparently Crucial Data

Several small populations of Hawaiian monk seals ( Monachus schauinslani ) exhibit male-biased adult sex ratios and "mobbing," an aggressive behavior in which adult males injure and often kill adult females and immature seals of both sexes during mating attempts. Mobbing appears to be limiting the growth of some populations of this endangered species. The frequency of mobbing deaths appears to increase as a population's sex ratio becomes increasingly male-biased, although the exact relationship between these two variables (the mobbing response) is unknown. We developed a stochastic demographic model of a small Hawaiian monk seal population using several different assumptions about the mobbing response. We used the model to explore the origins of male-biased sex ratios in monk seal populations and to determine whether it was possible, given the lack of data on the mobbing response, to evaluate the probable effects of alternative management strategies to address the mobbing problem. Small populations (100 to 200 seals) and those with slower growth rates were more likely to develop male-biased adult sex ratios. Almost all of our modeling scenarios supported the immediate removal of males from populations where mobbing occurs. Our conclusions were relatively unaffected when the assumptions regarding the mobbing response were varied. Thus, a model was helpful even when apparently crucial data were unavailable.     

A comparative study of (239,240)Pu in soil near the former Rocky Flats Nuclear Weapons Facility, Golden, CO

The Rocky Flats Nuclear Weapons Plant near Golden, CO released plutonium into the environment during almost 40 years of operation. Continuing concern over possible health impacts of these releases has been heightened by lack of public disclosure of the US Department of Energy (DOE) activities. A dose reconstruction study for the Rocky Flats facilities, begun in 1990, provided a unique opportunity for concerned citizens to design and implement field studies without participation of the DOE, its contractors, or other government agencies. The Citizens Environmental Sampling Committee was formed in late 1992 and conducted a field sampling program in 1994. Over 60 soil samples, including both surface and core samples, were collected from 28 locations where past human activities would have minimal influence on contaminant distributions in soil. Cesium-137 activity was used as a means to assess whether samples were collected in undisturbed locations. The distribution of plutonium (as (239,240)Pu) in soil was consistent with past sampling conducted by DOE, the Colorado Department of Public Health and Environment, and others. Elevated levels of (239,240)Pu were found immediately east of the Rocky Flats Plant, with concentrations falling rapidly with distance from the plant to levels consistent with background from fallout. Samples collected in areas south, west, and north of the plant were generally consistent with background from fallout. No biases in past sampling due to choice of sampling locations or sampling methodology were evident. The study shows that local citizens, when provided sufficient resources, can design and implement technical studies that directly address community concerns where trust in the regulated community and/or regulators is low.     

False positive fecal coliform in biosolid samples assayed using A-1 medium.

Two most probable number (MPN) methods-lauryl tryptose broth with Escherichia coli broth confirmation and direct A-1 broth incubation (A-1)--were compared for the enumeration of fecal coliform in lime-treated biosolid. Fecal coliform numbers were significantly higher using the A-1 method. Analysis of positive A-1 tubes, however, indicated that a high percentage of these were false positives. Therefore, the use of A-1 broth for 40 CFR Part 503 Pathogen Reduction (CFR, 1993) compliance testing is not recommended.     

Team mental models and team performance: a field study of the effects of team mental model similarity and accuracy

We conducted a field study of 71 action teams to examine the relationship between team mental model similarity and accuracy and the performance of real‐world teams. We used Pathfinder to operationalize team members' taskwork mental models (describing team procedures, tasks, and equipment) and teamwork mental models (describing team interaction processes) and examined team performance as evaluated by expert team assessment center raters. Both taskwork mental model and teamwork mental model similarity predicted team performance. Team mental model accuracy measures were also predictive of team performance. We discuss the implications of our findings and directions for future research. Copyright © 2006 John Wiley & Sons, Ltd.     

Heavier birds react faster to predators: individual differences in the detection of stalking and ambush predators

The relationship between body mass and reactions speed in response to a predatory threat is poorly understood. Theory predicts that different vigilance patterns are optimal for the detection of different predator types. We suggest that birds of different individual state might also differ in their speed of response dependent upon predator type. We used laboratory trials of wild caught chaffinches (Fringilla coelebs) to determine how between individual differences in chaffinch behaviour and state correlate with latency to react to a ground predator model (domestic cat), thus providing a comparison with previous work in the same model system using aerial predator models. In experiment 1, we observed chaffinch responses to a moving cat model, simulating a stalking predator. In experiment 2, we used a camouflaged cat model simulating an ambush predator. Both experiments show evidence suggesting heavier individuals (which previous literature has linked to impaired flight performance) responded more quickly to the model cat. Heavier individuals also had shorter interscan intervals. In contrast to a previous study, both experiments found individuals with a higher intake rate were not faster at responding to the cat model. In addition, individuals in experiment 1 that head turned more while scanning were slower to respond to the stalking cat model. Our work suggests that although heavier individuals may have impaired escape performance they appear to show behavioural compensation by allocating more attention to anti-predator behaviour and by modifying their interscan intervals, resulting in faster response times to a ground predator. We suggest more experiments investigating response time to different predatory types and explicitly manipulating state to elucidate cause and effect.     

4200 years of pine-dominated upland forest dynamics in west-central Mexico: human or natural legacy?

The pine-dominated forests of west-central Mexico are internationally recognized for their high biodiversity, and some areas are protected through various conservation measures including prohibition of human activity. In this region, however, there is evidence for human settlement dating back to ca. AD 1200. It is therefore unclear whether the present forest composition and structure are part of a successional stage following use by indigenous human populations during the past, or due to natural processes, such as climate. We present a study reconstructing the vegetation dynamics of pine-dominated forest over the past 4200 years using paleoecological techniques. Results from fossil pollen and charcoal indicate that, in this region, pine-dominated forests are the native vegetation type and not anthropogenically derived secondary succession. The predominant driving mechanism for the expansion of pine-dominated forest appears to be intervals of aridity and naturally induced burning. A close association is noted between pine abundance and longer-term climatic trends, including intervals of aridity between ca. 4200 and 2500, 1200 and 850, and 500 and 200 cal yr BP and shorter-term trends. Evident periodicity occurs in pine and Poaceae abundance every 80 years. These short-term quasi-periodic oscillations have been recorded in a number of lake and ocean sediments in Mexico and are thought to be linked to solar forcing resulting in drought cycles that occur at approximately the same time intervals.