Nitrogen versus phosphorus limitation in a subtropical coastal embayment (Moreton Bay; Australia): Implications for management

An approach combining nutrient budgets, dynamic modelling, and field observations of phytoplankton and nitrogen (N₂)-fixing Lyngbya majuscula following changes in wastewater N loads, was used to demonstrate that Moreton Bay is potentially phosphorus (P) limited. Modelling and nutrient budgeting shows that benthic N-fixation loads are high, allowing the system to overcome any potential N-limitation. Phytoplankton biomass has shown little change from 1991 to 2006 in the sections of Moreton Bay most impacted by wastewater effluents, despite a large reduction in wastewater N loads from 2000 to 2002. This is consistent with modelling that also showed no reduction in primary productivity associated with reduced N loads. Most importantly, there have been rapid increases in the occurrence of N-fixing L. majuscula in Moreton Bay as wastewater P loads have increased relative to wastewater N loads. This is also consistent with modelling. This work supports the premise that there may be fundamental differences in nutrient limitation of primary production between subtropical and temperate coastal systems due to differences in the importance of internal nitrogen sources and sinks (N-fixation and denitrification). These differences need to be recognised for optimum management of coastal systems.     

Swine odor analyzed by odor panels and chemical techniques

The National Research Council identified odors as a significant animal emission and highlighted the need to develop standardized protocols for sampling and analysis. The purpose of our study was to compare different odor sampling techniques for monitoring odors emitted from stored swine manure. In our study, odorous headspace air from swine manure holding tanks were analyzed by human panels and analytical techniques. Odorous air was analyzed by human panels using dynamic dilution olfactometry (DDO). Chemical analysis used acid traps for ammonia (NH?), fluorescence for hydrogen sulfide (H?S), and thermal desorption gas chromatography-mass spectrometry for volatile organic compounds (VOCs). Chemical analysis included the use of gas chromatography-olfactometry (GC-O) for determining key odorants. Chemical odorant concentrations were converted to odor activity values (OAVs) based on literature odor thresholds. The GC-O technique used was GC-SNIF. Dilution thresholds measured by different odor panels were significantly different by almost an order of magnitude even though the main odorous compound concentrations had not changed significantly. Only 5% of the key odorous VOCs total OAVs was recovered from the Tedlar bags used in DDO analysis. Ammonia was the only chemical odorant significantly correlated with DDO analysis in the fresh (1 wk) and aged manure. Chemical analysis showed that odor concentration stabilized after 5 to 7 wk and that HS was the most dominant odorant. In aged manure, neither volatile fatty acids (VFAs) nor HS was correlated with any other chemical odorant, but NH, phenols, and indoles were correlated, and phenols and indoles were highly correlated. Correlation of odorant concentration was closely associated with the origin of the odorant in the diet. Key odorants determined by chemical and GC-O included indoles, phenols, NH?, and several VFAs (butanoic, 3-methylbutanoic, and pentanoic acids).     

Comparisons of soil surface sealing methods to reduce fumigant emission loss

State and federal regulatory agencies depend on quality field data for determining the effects of agricultural management practices on fumigant emissions to develop sound, science-based policies and regulations on preplant soil fumigants. Field plot tests, using growers' standard field operation procedures, were used to simultaneously determine the effectiveness of several commonly proposed emission reduction methods, in a trial involving shank injection of Telone II [a.i. 1,3-dichloropropnene (1,3-D)] to a sandy loam soil to a target rate of 372 kg ha(-1). The experiment was conducted in late September 2008 in the San Joaquin Valley of California. Fumigant emissions were captured using dynamic flux chambers. The results showed that virtually impermeable film (VIF) reduced emissions >95% when compared to bare soil, and the glue joints in the film did not significantly affect the tarp performance. The VIF also created a more uniform distribution of gaseous fumigant in the soil profile, which would likely benefit pest control efficacy. Standard high-density polyethylene (HDPE) tarp reduced total 1,3-D emissions about 50% (higher than most reported values) in this trial, whereas postfumigation intermittent water treatments (seals) reduced cumulative emission losses by approximately 20%. Adding 49.4 Mg ha (equivalent to 20 tons per acre) of composted dairy manure to surface soils did not reduce 1,3-D emissions during this experiment. Use of VIF was the most promising technique in reducing emissions and has the potential to allow lower application rates while providing satisfactory pest control.     

Field evaluation of a new plastic film (vapor safe) to reduce fumigant emissions and improve distribution in soil

Preplant soil fumigation is an important pest management practice in coastal California strawberry production regions. Potential atmospheric emissions of fumigants from field treatment, however, have drawn intensive environmental and human health concerns; increasingly stringent regulations on fumigant use have spurred research on low-emission application techniques. The objectives of this research were to determine the effects of a new low-permeability film, commonly known as totally impermeable film (TIF), on fumigant emissions and on fumigant distribution in soil. A 50/50 mixture of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) was shank-applied at 314 kg ha in two location-separate field plots (0.4 ha each) in Ventura County, California, in fall 2009. One plot was surface-covered with standard polyethylene (PE) film, and the other was covered with TIF immediately after fumigant application. Data collection included emissions, soil-gas phase concentration profile, air concentration under the film, and soil residuals of the applied fumigants. Peak emission flux of 1,3-D and CP from the TIF field was substantially lower than from the PE field. Total through-film emission loss was 2% for 1,3-D and <1% for CP from the TIF field during a 6-d film covering period, compared with 43% for 1,3-D and 12% for CP from the PE field. However, on film-cutting, greater retention of 1,3-D in the TIF field resulted in a much higher emission surge compared with the PE field, while CP emissions were fairly low in both fields. Higher concentrations and a more uniform distribution in the soil profile for 1,3-D and CP were observed under the TIF compared with the PE film, suggesting that the TIF may allow growers to achieve satisfactory pest control with lower fumigant rates. The surging 1,3-D emissions after film-cutting could result in high exposure risks to workers and bystanders and must be addressed with additional mitigation measures.     

Participatory adaptation planning and costing. Applications in agricultural adaptation in western Kenya

Adaptation to climate change is an important theme in the strategy and policy of institutions around the world. Billions of dollars are allocated every year, based on cost estimates of actions to cope with, or benefit from the impacts of climate change. Costing adaptation, however, is complex, involving multiple actors with differing values and a spectrum of possible adaptation strategies and pathways. Currently, expert driven, top-down approaches dominate adaptation costing in practice. These approaches are subject to misallocation, with global funds not always reaching vulnerable communities in most need. This paper introduces an analytical framework called Participatory Social Return on Investment (PSROI), which provides a structured framework for multi-stakeholder planning, selection and valuation of appropriate methods of adaptation. The broader economic, social and environmental impacts of these adaptation actions are explored and valued through a participatory process. PSROI is strength-based, building local capacity and generating stakeholder buy-in. The financial valuation generated provides an additional tool for examining and prioritizing adaptation actions based on their impact. Results from a pilot of the PSROI framework in a smallholder farming community in Western Kenya provide empirical evidence for the difference between expert driven desk-based and ground-based cost estimates that involve local communities. There was an approximate 70 % reduction in the valuation of an agroforestry intervention, selected by the local community, when compared between the desk-based valuation and that of the local community, using primary field data. This reduced expectation of the desk-based PSROI is justified by coherent explanations such as lack of knowledge about the intervention, misconception about the potential costs and benefits, and the risk-averse nature of the farmers. These and other important insights are fundamental for planning and decision-making, as well as appropriate targeting and delivery of funding for adaptation.     

Challenges to the implementation of a sustainable development certification programme for the minerals and metals industry

Private, voluntary eco-labelling and certification programmes are being developed for a number of industries to promote and verify higher environmental, economic and social standards. In some cases, these initiatives have developed regardless of whether there is initial, broad support within industry. This article seeks to identify some of the challenges inherent in the implementation of a sustainable development certification programme for the minerals and metals industry. The article looks for guidance from initiatives that are drawn for the most part from other resource industries, most notably forestry. While the article takes a Canadian perspective, many of the challenges raised in the article are also applicable internationally. The article concludes that stakeholders can learn from other resource industries if a decision is made to develop a certification programme for the minerals and metals industry. Crucial to the long-term success of such a programme will be the establishment of a true partnership among stakeholders throughout the initiative's development. Crown Copyright.     

The Decline of Amphibians in California's Great Central Valley

Declines in amphibian populations are rarely reported on the community or ecosystem level. We combined broad-scale field sampling with historical analyses of museum records to quantify amphibian declines in California's Great Central Valley. Overall, amphibians showed an unambiguous pattern of decline, although the intensity of decline varied both geographically and taxonomically. The greatest geographical decline was detected in the counties of the Sacramento and San Joaquin Valleys. Two species, Rana aurora and Bufo boreas were identified as the most affected by decline, whereas Pseudacris regilla was the least affected. The Coast Range counties had little or no detectable decline. We provide new evidence implicating introduced predators as a primary threat. Introduced predators occur at lower elevations than native species, and our data indicate that for some native species there has been significant restriction to higher elevation sites from a formerly broader distribution. Our historical approach provides a strategy for identifying declining amphibian communities that complements more detailed, long-term monitoring programs and provides an assessment of the pattern of change that is a necessary prerequisite for the development of field experiments that test hypothesized mechanisms of change.     

Vested Interest theory and disaster preparedness

Three studies were designed to extend a combination of vested interest theory (VI) and the extended parallel process model of fear appeals (EPPM) to provide formative research for creating more effective disaster preparedness social action campaigns. The aim was to develop an effective VI scale for assessing individual awareness and ‘vestedness’ relevant to disaster preparedness. Typical preparedness behaviours are discussed with emphasis on earthquakes and tornados in particular. Brief overviews of VI and the EPPM are offered, and findings are presented from three studies (one dealing with earthquakes, and two with tornados) conducted to determine the factor structure of the key VI components involved, and to develop and test subscales derived from the two theories. The paper finishes with a discussion of future research needs and suggestions on how the new subscales may be applied in the design and execution of more effective disaster preparedness campaigns.     

Evaluation of the QUIC-URB fast response urban wind model for a cubical building array and wide building street canyon

This paper describes the QUIC-URB fast response urban wind modeling tool and evaluates it against wind tunnel data for a 7 × 11 cubical building array and wide building street canyon. QUIC-URB is based on the Röckle diagnostic wind modeling strategy that rapidly produces spatially resolved wind fields in urban areas and can be used to drive urban dispersion models. Röckle-type models do not solve transport equations for momentum or energy; rather, they rely heavily on empirical parameterizations and mass conservation. In the model-experiment comparisons, we test two empirical building flow parameterizations within the QUIC-URB model: our implementation of the standard Röckle (SR) algorithms and a set of modified Röckle (MR) algorithms. The MR model attempts to build on the strengths of the SR model and introduces additional physically based, but simple parameterizations that significantly improve the results in most regions of the flow for both test cases. The MR model produces vortices in front of buildings, on rooftops and within street canyons that have velocities that compare much more favorably to the experimental results. We expect that these improvements in the wind field will result in improved dispersion calculations in built environments.     

Dental Workers,Musculoskeletal CumulativeTrauma,and Carpal Tunnel Syndrome: Who is at Risk? A Pilot Study

A pilot study was conducted at a dental clinic to identify (a) the prevalence of musculoskeletal cumulative trauma disorders (MCTD), (b) associated symptoms (with special attention paid to carpal tunnel syndrome [CTS]), and (c) practitioners at risk. Videotapes, two questionnaires, a medical record review, and interviews were used. Forty-five dental workers participated and were classified into three categories: (a) dentists, (b) dental assistants and special assistants (DA/SA), and (c) dental hygienists and dental assistant-expanded function (DH/DAEF). Categorical data were analyzed using the chi- square statistic and risk ratios. The Fisher exact probability test was used for categorical data with a small cell. One or more symptoms associated with CTS were noted by 75.6% of the dental workers, 11% reported diagnosed CTS, and 53% reported back and shoulder pain. Both psychosocial factors and job demands appear to be associated with MCTD. All three categories of dental workers reported MCTD symptoms, and the DH/DAEF group was found to be at greatest risk for developing upper extremity symptoms, CTS, and back pain.