Attributional conflict between managers and subordinates: An investigation of leader-member exchange effects

The present study investigated the discrepancies, or conflict, between the attributions of leaders and members as a function of LMX quality and explored the relation between attributional conflict and subordinate job satisfaction, perceptions of equity, and turnover intentions. Data for the study were provided by 141 supervisor-subordinate dyads from the managerial ranks of a large manufacturing organization. Both parties of the dyad made attributions for subordinate loyalty, affect, and contributions, member behaviors identified as critical in previous LMX research. Limited support emerged for the hypothesis that attributional conflict would be greater in dyads where subordinates reported lower rather than higher LMX quality. Findings suggested that attributional discrepencies are due, in part, to the tendency of leaders to make more favorable attributions for subordinates reporting higher LMX quality than for subordinates reporting lower LMX quality. Results also revealed that, while attributional conflict was negatively related to subordinate satisfaction and perceptions of equity and positively related to turnover intentions, attributional conflict did not predict subordinate work outcomes when the effects of LMX quality were controlled. Implications of these findings were discussed.     

Stadtklima

This two-part review paper is attended to the urban climate. After referring to the spatial and temporal scales as well as to the historical developments in urban climate, Part 1 introduces the methods of measuring urban climate parameters and the characteristics of the urban climate in relation to its rural surroundings. Examples are given for some central-European cities. The premises and causes of the urban climate are discussed: the conversion of natural ground cover into sealed surfaces, anthropogenic heat release and emissions of air pollutants. The importance of factors like the behaviour of thermal and hydrological properties of urban surfaces which influence urban climate in the micro-and mesoscale are described by means of some examples. Implications for the resulting energy balance of urban surfaces are quantified in terms of the sub-surface heat flux, the sensible and latent heat flux densites. Part 2 (Main features and effects) describes the features and human-biometeorological effects of the urban climate, takes up planning aspects and discusses the impact of global warming to urban climate.     

Assessment of natural selection in a hybrid population of mussels: evaluation of exogenous vs endogenous selection models

We examined natural selection within a population of marine mussels, sampled in southwestern England in June 1991, containing a high frequency of hybrids between Mytilus edulis L. and M. galloprovincialis Lmk. This system is particularly tractable for the assessment of natural selection because hybridization is common and individual mussels can be aged, allowing changes in the frequency of hybrid genotypes among age classes to be determined. We show that strong viability selection occurs among hybrid genotypes which results in the virtual elimination of M. edulis–like genotypes from the population over a period of 3 years. Recombinant hybrid genotypes are intermediate in fitness, with M. edulis–like genotypes having a lower survival rate and M. galloprovincialis–like genotypes having a higher survival rate than genotypes of mixed ancestry. Since intermediate fitness for hybrid genotypes is inconsistent with endogenous selection models we conclude that the structure and position of this hybrid zone is probably generated by exogenous selection. This pattern of selection is a recurring feature of this hybrid population and likely occurs elsewhere in the hybrid zone. Selection against M. edulis–like genotypes appears to be offset by extensive immigration of larvae dispersed from pure populations of M. edulis. Received: 14 July 1997 / Accepted: 24 February 1998     

PCDD/F and dioxin-like PCB in human blood and milk from German mothers

Blood samples of pregnant women aged between 19 and 42 years at the time they gave birth and milk samples from the same women following delivery were collected between September 2000 and January 2003 from 169 participants living in an industrialized area of Germany (Duisburg birth cohort study). All samples were analyzed for their content of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) as well as dioxin-like and indicator polychlorinated biphenyls (PCB). Levels of WHO-TEq were in the range of 4.34-97.3 pg/g(lipid base) (median: 26.37, arithmetic mean: 28.36) for blood, or 3.01-78.7 pg/g(lipid base) (median: 26.40, arithmetic mean: 27.27) for milk, respectively. The four congeners 12378-PeCDD, 23478-PeCDF, 33'44'5-PeCB (# 126) and 233'44'5-HxCB (# 156) contribute the main share to total WHO-TEq. The contribution of PCDD/F in relation to PCB to total WHO-TEq was 60:40% in blood and 52:48% in milk. Good correlations of the contaminant levels in lipid base between both matrices were found. The distribution between blood and milk depends on the molecular weight of the substances. Higher chlorinated PCDD/F- and PCB-congeners were found in 2-4-fold higher concentrations in blood in relation to milk and the concentrations of lower chlorinated PCB-congeners were up to 2-fold higher in milk in relation to blood. The body burden of PCDD/F and PCB increases with age and decreases over the total nursing period. Women who had lived outside highly industrialized countries showed lower concentrations of PCDD/F and PCB. In some cases, elevated levels of PCB were observed when the women had previously lived in Eastern Europe for a long time. In comparison with recent data, the decline in human PCDD/F and PCB levels observed during the nineties seems to have stopped. The individual exposures of the infants due to breastfeeding within the first 18 months were calculated to be from 4.4 to 318 ng WHO-TEq (median: 106, arithmetic mean: 118). The actual mean daily exposure of a breastfed infant can be estimated to 131 pg WHO-TEq/kg(body weight).     

Metal translocation patterns in Solanum melongena grown in close proximity to traffic

The purpose of this study is to examine tissue patterns of metal (Cr, Ni, Cu, Cd, and Pb) concentrations in Solanum melongena cultivated in close proximity to traffic to help elucidate associated elemental deposition and soil-to-root and root-to-shoot transfers. Plants were cultivated in a commercial soil mix at three sites in Toronto, Canada. Metal concentrations were determined on microwave-digested bulk and rhizosphere soil and tissue samples per ICP-MS, along with two standard reference materials (NIST #1570a and #2709a). Unwashed and washed S. melongena samples were also analyzed, along with Origanum vulgare plants from the same sites, to assess the effectiveness of washing in reducing metal concentrations. The tissue distribution of Cr, Ni, Cu, and Pb demonstrated variability as a function of traffic proximity. Copper was found to easily translocate to roots in soils susceptible to waterlogging, while Cd had the highest soil-to-root and root-to-shoot translocation. The translocation of Cd was highest at the roadside site, due to a greater relative enrichment of this metal in the rhizosphere of S. melongena plants. Washing O. vulgare leaves was more effective in removing metal-associated particles compared to S. melongena samples. Cadmium uptake is of greatest concern given its toxicity and translocation potential.     

Determination of clindamycin and its metabolite clindamycin sulfoxide in diverse sewage samples

In a research project on risk management of harmful substances in water cycles, clindamycin and 12 further antibiotics were determined in different sewage samples. In contrast to other antibiotics, an increase of the clindamycin concentration in the final effluent in comparison to the influent of the sewage treatment plant (STP) was observed. A back transformation from the main metabolite clindamycin sulfoxide to clindamycin during the denitrification process has been discussed. Therefore, the concentration of this metabolite was measured additionally. Clindamycin sulfoxide was stable in the STP and the assumption of back transformation of the metabolite to clindamycin was confuted. To explain the increasing clindamycin concentration in the STP, the ratio of clindamycin sulfoxide to clindamycin was observed. The ratio increased in dry spells with concentrated samples and with long dwell time in the sewer system. A short hydraulic retention in waste water system and diluted samples in periods of extreme rainfall lead to a lower ratio of clindamycin sulfoxide to clindamycin concentration. A plausible explanation of this behavior could be that clindamycin was adsorbed strongly to a component of the sewage during this long residence time and in the STP, clindamycin was released. In the common sample preparation in the lab, clindamycin was not released. Measurements of clindamycin and clindamycin sulfoxide in the influent and effluent of STP is advised for sewage monitoring.     

Occurrence and removal of lidocaine,tramadol, venlafaxine,and their metabolites in German wastewater treatment plants

Purpose  

Some of the pharmaceuticals that are not extensively investigated in the aquatic environment are the anesthetic lidocaine (LDC), the analgesic tramadol (TRA), and the antidepressant venlafaxine (VEN). LDC metabolizes to 2,6-xylidine (2,6-DMA) and monoethylglycinexylidine (MEGX), TRA to O-desmethyltramadol (ODT), and VEN to O-desmethylvenlafaxine (ODV). Within this study, the distribution and behavior of these compounds in German wastewater treatment plants (WWTPs) were investigated.