Specific dynamic action affects the hydrostatic pressure tolerance of the shallow-water spider crab <Emphasis Type="Italic">Maja brachydactyla</Emphasis>

The bathymetric distribution of marine benthic invertebrates is likely governed by a combination of ecological and physiological factors. The present study investigates oxygen consumption and heartbeat rate in response to attempted feeding at 1, 100 and 150 atm in the shallow-water spider crab, Maja brachydactyla, from temperate European waters. No significant difference was evident between the resting heartbeat rate of specimens at 1 or 100 atm, which were 56 and 65 bpm, respectively (Mann–Whitney, U = 5382.0; n = 95, 98; p = 0.079). However, at 150 atm the resting heartbeat rate was significantly higher than that observed for 100 atm at 108 bpm (Mann–Whitney, U = 149.0; n = 45, 98; p < 0.001). At 150 atm, feeding was never observed and coupled with the elevated resting heartbeat rate; it is suggested by 150 atm continued survival is unfeasible. At 1 and 100 atm, feeding instigated a distinct increase in heartbeat rate, which remained elevated for over 30 h. This increase peaked within 1 h at 1 atm. At 100 atm, this required 4 h and postprandial oxygen consumption was significantly higher than at 1 atm (Kruskal–Wallis, H = 85.036; df = 2; p < 0.001). Elevated hydrostatic pressure is hypothesized to extend the duration and the total metabolic energy devoted to specific dynamic action. The metabolic requirements of feeding under hyperbaric conditions may even reach such a critical demand that feeding is entirely inhibited.     

Modelling the distribution of domestic ducks in Monsoon Asia

Domestic ducks are considered to be an important reservoir of highly pathogenic avian influenza (HPAI), as shown by a number of geospatial studies in which they have been identified as a significant risk factor associated with disease presence. Despite their importance in HPAI epidemiology, their large-scale distribution in monsoon Asia is poorly understood. In this study, we created a spatial database of domestic duck census data in Asia and used it to train statistical distribution models for domestic duck distributions at a spatial resolution of 1 km. The method was based on a modelling framework used by the Food and Agriculture Organisation to produce the Gridded Livestock of the World (GLW) database, and relies on stratified regression models between domestic duck densities and a set of agro-ecological explanatory variables. We evaluated different ways of stratifying the analysis and of combining the prediction to optimize the goodness of fit of the predictions. We found that domestic duck density could be predicted with reasonable accuracy (mean RMSE and correlation coefficient between log-transformed observed and predicted densities being 0.58 and 0.80, respectively), using a stratification based on livestock production systems. We tested the use of artificially degraded data on duck distributions in Thailand and Vietnam as training data, and compared the modelled outputs with the original high-resolution data. This showed, for these two countries at least, that these approaches could be used to accurately disaggregate provincial level (administrative level 1) statistical data to provide high resolution model distributions.     

Evaluations of combined zebrafish (Danio rerio) embryo and marine phytoplankton (Diacronema lutheri) toxicity of dissolved organic contaminants in the Ythan catchment,Scotland, UK

A wide variety of organic contaminants including pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) have previously been detected in surface waters in the river Ythan catchment, North East Scotland UK. While the concentrations detected were below Water Framework Directive Environmental Quality Standards (WFD-EQSs) environmental exposures to the diverse mixtures of contaminants, known and unknown, may pose chronic and/or sublethal effects to non target organisms. The present study assessed the embryo and algal toxicity potential of freely dissolved organic contaminants from the Ythan catchment using silicone rubber passive sampling devices (SR-PSDs) and miniaturised bioassay techniques. Zebrafish (Danio rerio) embryos and marine phytoplankton species (Diacronema lutheri) were exposed to extracts from SR-PSDs deployed at different locations along the river Ythan and an undeployed procedural blank. Statistically significant developmental and algal toxicities were measured in all tests of extracts from deployed samples compared with the procedural blanks. This indicates environmental exposure to, and the combined toxicity potential of, freely dissolved organic contaminants in the catchment. The present and previous studies in the Ythan catchment, coupling SR-PSDs and bioassay techniques, have both helped to understand the interactions and combined effects of dissolved organic contaminants in the catchment. They have further revealed the need for improvement in the techniques currently used to assess environmental impact.     

Persistence,variance and toxic levels of organochlorine pesticides in fluvial sediments and the role of black carbon in their retention

The present study assesses the persistence and variation of organochlorine pesticides (OCPs) and their regulation by total organic carbon (TOC) and black carbon (BC) in freshwater sediment. Sediment samples from the Yamuna River, a major tributary of the Ganges (one of the most populated and intensively used rivers in Asia), had high levels of Σ₂₀OCPs (21.41 to 139.95 ng g^?1). β-Hexachlorocyclohexane (β-HCH) was the most predominant component. ΣHCH and Σdichloro-diphenyl-trichloroethane (DDT) constituted ~86 % of Σ₂₀OCPs. Isomer ratios indicated fresh usage of lindane, DDT and technical-grade HCH. Toxicological comparison with freshwater sediment quality guidelines showed γ-HCH and DDT at high levels of concern. β-HCH, α-HCH, endrin, heptachlor epoxide, dichloro-diphenyl-dichloroethane (DDD), dichloro-diphenyl-dichloroethylene and chlordane were above some of the guideline levels. TOC and BC had mean concentrations of 1.37?±?0.51 % and 0.46?±?0.23 mg g^?1, respectively. BC constituted 1.25 to 10.56 % of TOC. We observed low to moderate correlations of BC with isomers of HCH, p,p′-DDT and methoxychlor while of TOC with Σ₂₀OCPs, γ-HCH, endosulfan sulfate and methoxychlor. Principal component analysis enabled correlating and clustering of various OCPs, BC and TOC. OCP distribution was related with pH, electrical conductivity, soil moisture and finer fractions of sediment. OCPs with similarity in properties that determine their interactions with carbonaceous components of sediment clustered together. A number of factors may, thus, be involved in the regulation of interactive forces between BC and OCPs. BC in this study may be more important than TOC in the retention of some OCPs into fluvial sediments, thereby reducing their bioavailability. The finding is probably the first of its kind to report and emphasises the role of BC in the persistence of OCPs in fluvial sediments.     

Usefulness and uses of climate forecasts for agricultural extension in South Carolina,USA

Farmers and extensionists can use forecasts about agro-climatic conditions to reduce risks of agricultural production. Eighteen extension agents, researchers, consultants, and farmers provided feedback about decision support tools that utilize such forecasts during focus groups that were conducted in Florence, South Carolina on January 14, 2011. Climate Risk and County Yield Database were the tools most selected as potentially useful for agricultural extension in South Carolina. An irrigation scheduler was the most frequently mentioned tool to be developed. Also, a survey of Clemson University’s extension personnel was conducted in January and February 2011 to assess interest of South Carolina’s growers and producers in using climate forecasts, eleven potential uses of climate forecasts by extension’s clientele, and potential usefulness to extensionists of twelve specific forecasts. Clemson’s extensionists represent approximately 97 % of the state’s agricultural extensionists. They are more likely than not to agree that growers and producers are interested in using climate forecasts. Most of the state’s extension personnel also think that farmers could use a climate forecast to improve irrigation management and planting schedules. A majority of the state’s extensionists thinks that a freeze alert could be useful to them and the proportion that thinks the forecast could be useful exceeds the proportion that thinks any other forecast could be useful. Most extensionists also think that a forecast of plant moisture stress could be useful to help farmers schedule irrigation. The key survey results are remarkably similar to those from surveys of extension personnel at North Carolina State University in early 2009 and University of Florida in late 2004.     

Effects of nozzle types and 2,4-D formulations on spray deposition

The objective of this study was to evaluate the effects of nozzle types and 2,4-D formulations on spray deposition on different targets. Two field experiments were carried out in a completely randomized design, and treatments were arranged in a factorial scheme. Species in experiment 1 were Sumatran fleabane (Conyza sumatrensis) and Brazil pusley (Richardia brasiliensis) and in experiment 2 were soybeans (Glycine max) and Benghal dayflower (Commelina benghalensis). For both experiments, the first factor corresponded to spray nozzles with different settings (AD 110.015 – 61 and 105 L ha^?1; AD 015-D – 75 and 146 L ha^?1; XR 110.0202 – 200 L ha^?1; and ADIA-D 110.02 – 208 L ha^?1) and the second factor consisted of two formulations of 2,4-D (amine and choline). The formulation of 2,4-D choline has contained Colex-D? Technology. Similar or higher spray deposition was observed on the leaves and artificial targets when using 2,4-D choline as compared to the 2,4-D amine formulation, and these differences in deposition were more evident for nozzles applying lower spray volumes. Deposition was more affected by nozzle type when amine formulation was used, compared to choline formulation.     

Cross-sectional biomonitoring study of pesticide exposures in Queensland,Australia, using pooled urine samples

A range of pesticides are available in Australia for use in agricultural and domestic settings to control pests, including organophosphate and pyrethroid insecticides, herbicides, and insect repellents, such as N,N-diethyl-meta-toluamide (DEET). The aim of this study was to provide a cost-effective preliminary assessment of background exposure to a range of pesticides among a convenience sample of Australian residents. De-identified urine specimens stratified by age and sex were obtained from a community-based pathology laboratory and pooled (n = 24 pools of 100 specimens). Concentrations of urinary pesticide biomarkers were quantified using solid-phase extraction coupled with isotope dilution high-performance liquid chromatography–tandem mass spectrometry. Geometric mean biomarker concentrations ranged from <0.1 to 36.8 ng/mL for organophosphate insecticides, <0.1 to 5.5 ng/mL for pyrethroid insecticides, and <0.1 to 8.51 ng/mL for all other biomarkers with the exception of the DEET metabolite 3-diethylcarbamoyl benzoic acid (4.23 to 850 ng/mL). We observed no association between age and concentration for most biomarkers measured but noted a “U-shaped” trend for five organophosphate metabolites, with the highest concentrations observed in the youngest and oldest age strata, perhaps related to age-specific differences in behavior or physiology. The fact that concentrations of specific and non-specific metabolites of the organophosphate insecticide chlorpyrifos were higher than reported in USA and Canada may relate to differences in registered applications among countries. Additional biomonitoring programs of the general population and focusing on vulnerable populations would improve the exposure assessment and the monitoring of temporal exposure trends as usage patterns of pesticide products in Australia change over time.     

Putting time in perspective: How and why construal level buffers the relationship between wait time and aggressive tendencies

We spend a substantial part of our daily life waiting, and unfortunately, wait time can fuel aggressive tendencies. Our study examines the relationship between wait time, perceived wait time, and aggressive tendencies from a construal level perspective. In Study 1, we found that the higher the construal level, the stronger the relationship between actual and perceived wait time and the stronger relationship between perceived wait time and aggressive tendencies. In Study 2, we manipulated construal level and found that power explains the moderating impact of construal on the wait—aggressive tendencies relationships. Results demonstrate the role of construal in explaining both perceived wait time and aggressive responses to long wait times, suggesting that mental construal influences both the psychological experience of time and the subsequent reaction to that experience. Overall, these results contribute to research on subjective time perspective by enhancing the knowledge and understanding of the determinants and effects of perceived wait time.     

Ecological footprints and shadows in an urban estuary, Narragansett Bay, RI (USA)

Because the rise of cities in North America was much later than in many other parts of the world, their connections to the hinterland were influenced early in their development by railroads and steam-powered water transport. These fossil fuel-based links made it possible to widely separate the ??upstream?? autotrophic supporting systems from the heterotrophic cities. Here, we take a different look at the connection between a city (Providence, RI, USA) and its supporting natural systems by focusing on the export of industrial and metabolic wastes from the city to the ??downstream?? coastal ecosystem in Narragansett Bay. In this way, we can track the history of a city by examining the concentrations of nutrients, metals, and hydrocarbons in the water and sediments of the estuary. In the greater Providence metropolitan area at the head of Narragansett Bay, there was rapid population and industrial expansion during the 1800s without the proper infrastructure to deal with water supply for public safety and health. On the other hand, the absence of a public water supply kept industrial and metabolic wastes largely on land. However, from the fall of 1871, on with the construction of a public water supply and sewer system, human wastes began flowing into the estuary. By reconstructing the historical record of metals and other pollutants, we illustrate clear temporal and spatial gradients of urban impact on the bay. Unfortunately, while numerous studies during the 1970s and 1980s focused on documenting metal and hydrocarbon pollution in the bay, there has been little effort to quantify the impact of mitigation efforts that have greatly reduced the input of metals and hydrocarbons to the system. Nutrient reductions are more recent and ongoing.