Modelling nitrogen fluxes at the landscape scale

The distribution and impacts of different nitrogen pollutants are inextricably linked. To understand the problem fully, the interactions between the different pollutants need to be taken into account. This is particularly important when it comes to abatement techniques, since measures to reduce emissions of one nitrogen pollutant can often lead to an increase in another. This project represents a step towards greater understanding of these issues by linking together new and existing nitrogen flux models into a larger framework. The modelling framework has been constructed and some of the nitrogen flows between fields, farms and the atmosphere have been modelled for a UK study area for typical farm management scenarios.     

Applying metabolic fingerprinting to ecology: The use of Fourier-transform infrared spectroscopy for the rapid screening of plant responses to N deposition

The potential for metabolic fingerprinting via Fourier-transform infrared (FT-IR) spectroscopy to provide a novel approach for the detection of plant biochemical responses to N deposition is examined. An example of spectral analysis using shoot samples taken from an open top chamber (OTC) experiment simulating wet ammonium deposition is given. Sample preparation involved oven drying and homogenisation via mill grinding. Slurries of a consistent dilution were then prepared prior to FT-IR analysis. Spectra from control, 8 and 16 kg N ha^–1 yr^–1 treatments were then subjected to cross-validated discriminant function analysis. Ordination diagrams showed clear separation between the three N treatments examined. The potential for using Calluna vulgaris (L.) Hull as a bioindicator of N deposition is further evident from these results. The results also clearly demonstrate the power of FT-IR in discriminating between subtle phenotypic alterations in overall plant biochemistry as affected by ammonium pollution.     

Impact of Land Use on Soluble Organic Nitrogen in Soil

Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO ₃ ^– , NH ₄ ⁺ ) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention. SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K.     

Assessing the Performance Level of a Water System

Water, Air, &; Soil Pollution: Focus - What should System Managers prefer? Systems that never fail or systems that remain safe during a failure? The present paper tries to give an answer to this...     

The Chemical Recycling of PET in the Framework of Sustainable Development

In this investigation, all the techniques used in the chemical recycling of polyethylene terephthalate (PET) are critically reviewed according to the overall benefits together with the environmental surcharge that they cause. Those, which are consistent with the principles of sustainable development, are indicated. Experimental data are presented for the acid hydrolysis of PET and compared with previous results on the alkaline hydrolysis of PET with, or without, the use of a phase transfer catalyst. Overall material balances are carried out for the hydrolysis of PET. Finally, it can be postulated that recycling according to the scheme: is the only one within the framework of sustainable development. Therefore, the recycling of PET does not only serve as a partial solution to the solid waste problem but also contributes to the conservation of raw petrochemical products and energy.     

Electroremediation: A study of the influence of buffering behavior in contaminated soils

This article presents the results of an experimental study conducted to evaluate the behavior of two types of andisol soils found in Tenerife, Canary Islands, Spain. The soils were evaluated in relation to their buffering capacity when confronted with acid and alkaline fronts generated during electroremediation treatment. The study was conducted using a cell, which established a continuous flow of distilled water through electrode chambers to remove H⁺ and OH^? generated during electrolysis. The results indicate that the soils had sufficient buffer capacity to support variations in pH independent of the maintenance of flow of solution in the electrode chambers. Although the mechanism of migration was not affected, the flow of water favored the movement of ions by diffusion monitoring of the electrolytic current allowed for a real‐time parameter to act as an indicator of the quantity of ions available in regions near the electrodes. © 2004 Wiley Periodicals, Inc.     

Interpreting workplace identities: the role of office décor

Using qualitative methods, I examine how employees in corporate office environments interpreted a variety of relatively permanent office décor (e.g., furniture, photos, personal mementos) as indicators of their colleagues' workplace identities (i.e., central and enduring categorizations regarding employees' status and distinctiveness in the workplace). Similar to the encoding of behavioral cues of identity, findings suggest that interpretation of physical identity markers begins with either (1) a top‐down process of social categorization, in which specific rules are applied to encoding a few, focal, and visually salient pieces of office decor as evidence of management prototypes, or (2) a bottom‐up process of social categorization, in which a variety of physical artifacts are examined and compared to specific managerial exemplars to develop a complex representation of workplace identity. Findings also suggest that some of the unique attributes of physical identity markers (i.e., their potential to be viewed independently from their displayer, and their relative permanence) may be associated with the focus of each profiling process (i.e., on interpreting status vs. distinctiveness, and consistency vs. change). Copyright © 2004 John Wiley & Sons, Ltd.     

Workplace deviance,organizational citizenship behavior,and business unit performance: the bad apples do spoil the whole barrel

The influences of organizational citizenship behavior (OCB) and workplace deviant behavior (WDB) on business unit performance were investigated using data from branches of a fast food organization. Data included measures of WDB and OCB obtained from staff, ratings of performance provided by supervisors, and objective measures of performance. It was found that WDB was negatively and significantly associated with business unit performance measured both subjectively and objectively. OCB, however, failed to contribute to the prediction of business unit performance beyond the level that was achieved by WDB. It appeared, therefore, that the presence of deviant employees among business units impinges upon the performance of the business unit as a whole, whereas OCBs had comparatively little effect. Copyright © 2004 John Wiley & Sons, Ltd.     

Gender in the boss–subordinate relationship: a Nigerian study

The present study examines the interaction effect of gender of both subordinates and supervisors on subordinates' perception of differentiation of boss–subordinate relationship in an African setting. Data was collected from a total of 60 boss–subordinate dyads in four‐sex combinations obtained through a survey of a large five‐star hotel in Abuja, Nigeria. Results revealed that subordinates in opposite‐sex dyads perceived better quality of exchange than those in same‐sex dyads. The strongest quality of exchange was perceived in male boss–female subordinate dyad, while the weakest was perceived in female boss–female subordinate dyad. This emphasizes the importance of gender in the differentiation of boss–subordinate relationships in an African setting. Copyright © 2004 John Wiley & Sons, Ltd.     

Decoupling task and relationship conflict: the role of intragroup emotional processing

The present paper focuses on the role of emotion in intragroup conflict processes. We propose that how group members handle emotion affects intragroup interactions and has implications for task and relationship conflict. Three types of variables—collective emotional intelligence, intragroup relational ties, and conflict‐relevant interactional norms—constrain negative emotionality and may determine whether task conflict results in damaging relationship conflict. The moderating influence of these variables is discussed, as are compositional issues associated with measuring them. Copyright © 2004 John Wiley & Sons, Ltd.