Relocation attitudes and adjustment: A longitudinal study

This study identified correlates of attitude toward an impending employer-initiated relocation, then followed up by predicting post-transfer attitude and adjustment difficulty in the same sample. Predictors suggested by past research on mobility attitudes (i.e. demographic characteristics and attributes of the pre-move location) were less important in explaining pre-move attitude toward the transfer than were expected attributes of the new location. After the move, experienced aspects of the new location such as role ambiguity, degree of advancement, and community and job satisfaction were the strongest predictors of overall post-move attitude and adjustment difficulty. In many cases, pre-move expectations about attributes of the new location were not related to affect or adjustment after the move, suggesting that pre-move expectations may have been inaccurate. Implications for theory, research, and organizational practice are discussed.     

Ammonium and free amino acid uptake by a deep-sea mussel (Bathymodiolus sp., undescribed) containing methanotrophic bacterial symbionts

The morphology of the lophophore and mouth was measured for freshly collected colonies of seven common bryozoan reef species at three sites along the central Caribbean coast of Panamá during the dry season, from the end of December 1988 through May 1989. Characters measured or scored include the number of tentacles, circumference of the lophophore, abanal and anal tentacle length, abanal and anal tentacle spacing, and perimeter of the mouth. Taxa studied include three species each of Stylophoma Levinsen, and Steginoporella (Smitt), and one species of Trematooecia Osburn. Individuals were collected from both continental and offshore fringing reefs from depths of 1 to>30 m. Terrestrial runoff from heavy tropical rains, sedimentation, and sea exposure vary greatly between sites. Congeneric species showed small but consistent differences in lophophore size, but little or no difference in spacing of tentacles or perimeter of the mouth. This suggests that closely related species feed on similarly sized particles despite their overall differences in zooidal size. Lopophore morphology also varied intraspecifically between reefs, particularly in the length of the tentacles and spacing between tentacles. Patterns of variation were similar for all species, which implies that species shift their diets in similar directions between the different reefs. The combination of these patterns suggests that niche diversification in feeding does not occur among congeneric species in the cheilostomes examined.     

A social appraisal of beverage containers recycling : A UK perspective

A social appraisal of the beverage container involves assessment of external costs. Analysis of available data shows that the returnable generates less external costs than the non-returnable, though refinement of the UK situation requires more detailed data. The ranking depends on the returnable's trippage rate, but it seems the returnable can achieve the trippage needed to make it socially preferable.     

Dissolution of 226Radium from pipe-scale deposits in a public water supply

This study was undertaken to determine if dissolution of 226Radium from pipe-scale deposits contributes to enhanced waterborne 226Radium concentrations at the point of use. Water samples were collected from residential water customers of a small rural Iowa town. Sites were evenly divided between new and old water main connections. Daily samples were collected from the point-of-entry water. Point-of-use 226Radium concentrations ranged from 0.4 to 12.9 pCi L-1 (0.01 to 0.5 Bq L-1). The mean 226 Radium concentration for homes connected to old water mains was significantly higher than the mean 226Radium concentration of homes connected to new water mains, mean(standard deviation) equal 8.3(1.1) and 5.3(0.8) pCi L-1 [0.3(1.1) and 0.2(0.8) Bq L-1], respectively. 226Radium concentrations of the point-of-entry water ranged from 5.0 pCi L-1 to 10.3 pCi L-1 (0.2 Bq L-1 to 0.4 Bq L-1). This study indicates considerable variability of 226Radium exposure from drinking water among residents of the same water supply and has implications for regulatory compliance and exposure assessment in epidemiologic studies.     

Heavy metals and marine diatoms: Influence of dissolved organic compounds on toxicity and selection for metal tolerance among four species

Experiments were conducted to determine whether diatom clones isolated from waters (Corio Bay or Hobson's Bay, Australia) chronically contaminated with heavy metals were more metal-resistant than clones of the same species isolated from cleaner waters (Bass Strait). Four species (2 clones per species) and 3 metals (Cu, Zn, Cd) were examined. The growth response of each clone to metal additions was assessed in both Corio Bay water and Bass Strait water. Generally, Cu was readily chelated and the most toxic metal and Cd the least chelated and least toxic. Toxicity of Cu to growth was found to be directly related to cellular Cu levels, which in turn were mediated by dissolved organic compounds in seawater. Corio Bay water had a greater metal-complexing capacity than Bass Strait water, and metal additions generally proved more toxic to each clone when in Bass Strait water. Ultraviolet irradiation eliminated differences between the water types. Relative to Bass Strait clones, no trend of enhanced metal tolerance was noted among the Corio Bay and Hobson's Bay clones; on the contrary the Corio Bay and Hobson's Bay cells were generally less to lerant of metals than were their Bass Strait counterparts, being particularly affected when in Bass Strait water. The results suggest that metal additions to waters rich in dissolved organic compounds would likely have less effect (in terms of direct toxicity and as a selective agent for metal tolerance) on resident phytoplankters than similar additions to waters low in organics.Publication No. 274 in the Ministry for Conservation, Environmental Studies Series     

Metabolic maintenance costs of the suspension feeder Styela plicata

The bioenergetic basis of the biannual reproductive cycle of the solitary tunicate Styela plicata was investigated in order to evaluate hypotheses concerning the lack of larval settlement in summer. The rate of ingestion and absorption efficiency were measured in order to provide an estimate of the rate at which material was made available for maintenance, growth, and reproduction. At a given temperature the rate of ingestion was proportional to the 0.7 power of wet mass. the ingestion rate increased rapidly with increasing temperature between 12° and 18°C (Q₁₀3), but was independent of temperature between 18° and 28°C. Absorption efficiency was independent of temperature and body size and averaged approximately one-third for both carbon and nitrogen. Metabolic maintenance costs were estimated from measurements of oxygen consumption and excretion of ammonia and urea reported for s. plicata. These require only 18±11% of the carbon and 37±22% of the nitrogen absorbed from the gut of S. plicata over the temperature range 12° to 28°C. Metabolic maintenance makes no excessive demands on the material absorbed in the gut at a particular time of year, and a surplus of carbon and nitrogen substrate is available throughout the year for growth and reproduction. Predation on larvae and young adults may be responsible for the low rate of settlement observed in summer months.     

Determination of self-accelerating decomposition temperatures using the Accelerating Rate Calorimeter

A self-accelerating decomposition temperature (T_SADT is the minimum ambient air temperature at which a reactive material of specified stability decomposes in a specified commercial package in a period of 7 days or less. Values for T_SADT are determined to decide whether a substance should be subject to temperature control during transport. Values of T_SADT calculated using the Accelerating Rate Calorimeter (ARC) and techniques suggested by Wilberforce and the authors are compared to those measured by oven stability testing. The methodology and the advantages of using the ARC to obtain T_SADT values are discussed.     

Recovery processes in lotic ecosystems: Limits of successional theory

The concept of succession has a distinguished history in general ecology and has been applied to stream ecosystems with some success. Succession in streams is largely secondary, follows initial floristics models, and occurs through a variety of mechanisms. The process is moderately predictable but is highly influenced by “climatic” factors, particularly nutrient chemistry. In desert streams, succession does not result in a climax state. While evidence is slim, succession may not be a significant process in streams of certain types or in certain regions. Successional theory is difficult to apply in spatially heterogeneous, hierarchically organized ecosystems. It also suffers in being only one component of a better integrated concept, that of ecosystem stability, which deals more directly with disturbance and ecosystem resistance in addition to resilience (which encompasses succession). Succession has so suffered from a half century of confusion that a strong case can be made for abandoning the term, at least as it applies in streams, in favor of the broader view provided by stability theory.