Planning behavior and perceived control of time at work

This study investigated two mediation models of time management. The first model consisted of parts of Macan's ( 1994 ) model. The second model combined this model with Karasek's ( 1998 ) Job Demand–Control model. Two sets of self‐report questionnaires were collected and were analyzed using structural equation modeling. The first model, in which perceived control of time was hypothesized to fully mediate the relation between planning behavior and work strain, job satisfaction, and job performance, was found to be less adequate than the second model, which added workload and job autonomy as independent variables. Results also indicated that partial, rather than full, mediation of perceived control of time fitted the data best. The study demonstrated the importance of studying both planning behavior and job characteristics, which was not part of past research. Copyright © 2004 John Wiley & Sons, Ltd.     

TRINITY RIVER BASIN,TEXAS1

ABSTRACT: In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) was among the first 20 study units to begin investigations under full-scale program implementation. The study-unit investigations will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. The environmental setting consists of both physical and cultural factors. Physical characteristics described include climate, geology soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, and reservoir operations. Major water-quality categories are identified and some of the implications of the environmental factors for water quality are presented.     

Flanders’ urbanity — an outline

This article deals with Flanders’ urbanity. At the moment Flanders, a part of Belgium, is responsible for its own town and country planning. Nevertheless, today's picture of urbanity is, for the greatest part, the result of Belgian policy. The results are nothing to be proud of. In fact Flanders has no urbanity anymore, nor a real rurality. Everywhere in the countryside there are houses and other constructions; on the other hand and consequently the centres of cities and villages are in decay. The following text tries to draw, very briefly, the problems and the development of the problems in urban and rural Flanders. The roots have to be searched in the 19th century, especially in the constitution of Belgium, which is one of the most liberal on earth. The first part of the article is dealing with the history of urbanisation, whilst the second part deals with some recent evolutions in housing and housing policy, in employment and employment policy, in transport and transport policy. Finally, the third part is concerned with the town and country planning which has to structure the developments in spatial use for housing, industrial building and so on, but which has failed.     

Natural fire management in National Parks

An evolving understanding of ecological processes, together with ambiguities in National Park Service policy, have led to multiple interpretations of the role of management in our large natural area National Parks. National Park Service management policies must be dynamic and responsive to changes in scientific knowledge and societal values. We propose that the principal aim of NPS resource management in natural areas is the unimpeded interaction of native ecosystem processes and structural elements. The case of the changing role of natural fire management is used as an example in developing this rationale.     

Environmental equity in the vicinity of Amsterdam Airport: The interplay between market forces and government policy

This paper examines the impact of the interplay between market forces and government policy on environmental equity in the vicinity of Amsterdam Airport in the Netherlands. Despite pressure on space and the presence of the international airport, exposure to the higher levels of traffic noise, NO₂ and external safety risks, and accumulation of traffic noise and NO₂ (‘bads’) was rather limited and generally distributed fairly equally among income categories, probably as a result of environmental regulations. However, lower-income categories had less access to lower levels of traffic noise, NO₂ and public green space (‘goods’) than higher-income categories, which may be explained by both historical processes and market forces. Policy makers seem to accept a higher environmental burden on the regional population because of the benefits for the national economy generated by Amsterdam Airport.     

Dynamic Control Switching Applied to Water Resource Management Simulation1

Abstract: Simulation of water resource management in hydrological numerical models is often limited to simple expressions such as rulecurves. More complex management requires additional layers of abstraction. Rulecurves tend to be simplistic, while abstraction implies expertise to convert management policies to a form which may not be recognizable by operators. The Regional Simulation Model (RSM) attempts to bridge this gap with the Management Simulation Engine (MSE). MSE allows dynamic switching of control algorithms facilitating hybrid control of modeled structures, even though the individual controllers are widely different. Use of hybrid controllers can simplify expression of complex management controls. This article details the architecture of the MSE that enables hybrid control. A model application is examined in which a set of tuned fuzzy controllers are dynamically switched with piecewise linear flood controllers to simulate a hybrid control scheme. The application models a Florida water conservation area and demonstrates effective flood control without sacrificing the tuned performance of the fuzzy controllers.     

Prey capture by Pisaster brevispinus (Asteroidea: Echinodermata) on soft substrate

Observations on the subtidal seastar Pisaster brevispinus (Stimpson) indicate that this predator can extend the central tube feet into sand-mud substrate for a distance roughly equal to the radius of the seastar. Field and laboratory evidence demonstrates the use of the elongated tube feet by the asteroid for the capture of burrowed prey items. A relationship between predator size and the size of juveniles of the deep-burrowing clam Tresus nuttallii taken as prey is a product of the ability of larger seastars to extend the tube feet further into the substrate and capture deeper prey. The role of P. brevispinus as an important subtidal predator along the Pacific Coast of North America is discussed.     

Modelling impacts of alternative farming management practices on greenhouse gas emissions from a winter wheat–maize rotation system in China

Agricultural production plays an important role in affecting atmospheric greenhouse gas concentrations. Field measurements were conducted in Quzhou County, Hebei Province in the North China Plains to quantify carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions from a winter wheat–maize rotation field, a common cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, Denitrification–Decomposition or DNDC, for its applicability for the cropping system. The validated DNDC was then used for predicting impacts of three management alternatives (i.e., no-till, increased crop residue incorporation and reduced fertilizer application rate) on CO₂ and N₂O emissions from the target field. Results from the simulations indicated that (1) CO₂ emissions were significantly affected by temperature, initial SOC, tillage method, and quantity and quality of the organic matter added in the soils; (2) increases in temperature, initial SOC, total fertilizer N input, and manure amendment substantially increased N₂O emissions; and (3) temperature, initial SOC, tillage, and quantity and quality of the organic matter added in the soil all had significant effects on global warming. Finally, five 50-year scenarios were simulated with DNDC to predict their long-term impacts on crop yield, soil C dynamics, nitrate leaching losses, and N₂O emissions. The modelled results suggested that implementation of manure amendment or crop residue incorporation instead of increased fertilizer application rates would more efficiently mitigate GHG emissions from the tested agro-ecosystem. The multi-impacts provided a sound basis for comprehensive assessments on the management alternatives.     

Common criteria for the redefinition of Intermediate Less Favoured Areas in the European Union

This article defines eight key climate, soil and terrain criteria that have been developed for the future delimitation of the Intermediate Less Favoured Areas (LFAs) support, a measure of the Common Agricultural Policy. The LFA scheme has existed since 1975 and is a broad mechanism for improving the viability of agriculture in areas with natural handicaps. The common criteria have been developed for the European Commission's Directorate-General for Agriculture and Rural Development to satisfy the objectives in the Rural Development Policy 2007–2013 (Axis II), which aim to improve the environment and the countryside by more sustainable land management. The criteria were developed by experts, coordinated by the European Commissions Joint Research Centre, to meet the requirement for a robust and harmonised approach of identifying areas that experience natural constraints to agriculture throughout the EU 27 Member States. The criteria proposed are: temperature, heat stress, drainage, soil texture and stoniness, soil rooting depth, soil chemical properties, soil moisture balance and slope. Each criterion is described and an indicative threshold for assessment of its impact on agriculture is provided. The criteria are currently being tested by the EU Member States for a future possible legislation.     

Chronosequence analysis of two enclosure management strategies in degraded rangeland of semi-arid Kenya

The establishment of enclosures has become an important measure to combat land degradation in many of the world's semi-arid rangelands. In view of the increased pressure exerted by this land reclamation strategy on the neighbouring agricultural lands, knowledge of the time required for restoring vegetation cover and soil health, and of the potential positive impact of an adapted management strategy, is highly required. This paper assesses the vegetation and soil rehabilitation in a 23-year chronosequence of two different enclosure management types. In the severely degraded, semi-arid Njemps Flats plain of the Lake Baringo Basin in Kenya communal enclosures characterised by high quality inputs and strict control, and private enclosures managed by individual farmers, were installed since the 1980s. Six communal enclosures (3–17 years since establishment) and six private enclosures (13–23 years since establishment) were selected. Vegetation cover was estimated along three 50 m transects set within each enclosure and in the adjacent open grazing area using the point-to-line transect method. Five 0.5 m² quadrats systematically placed alongside each transect were sampled for herbaceous standing biomass and topsoil physical, chemical and biological analyses. Grass cover and herbaceous biomass production proved to be the most responsive biotic parameters under both management types, whereas the recovery of the forbs was unsuccessful. Under communal management, the biomass production fully recovered up to its optimal level as recorded in the neighbouring nature reserves. Within private enclosures however, the adopted management strategies seriously restricted biomass production to a significantly lower level. Soil quality generally recovered more slowly with time. Significant improvements compared to the open rangeland were recorded in topsoil bulk density, organic C and total N stocks, and microbial biomass C and N stocks of the communal enclosures. Unlike the communal enclosures, only topsoil bulk density and the microbial biomass C stock showed a significant difference in the private enclosures. With respect to C and total N stocks, and the microbial biomass N a non-significant improving trend was recorded. The level of chemical and biological soil quality obtained under both management types is still low and draws the attention to the importance of careful monitoring of grazing and grass cutting activities under both enclosure management strategies. The chronosequences further highlight the potential of some well-managed private enclosures, whereas intrinsic soil properties such as high alkalinity, as well as changes in management, limit the rehabilitation of some other private as well as communal enclosures.