Temporal - and dose-related characteristics of biochemical and morphological alterations in the hamster induced by 2,3,7,8-tetrachlorodibenzo- -dioxin

The temporal - and dose-related characteristics of hepatic enzymes induced and toxic responses elicited in the hamster by 2,3,7,8-tetrachlorodibenzo- -dioxin were examined. The results demonstrate a dissociation of the induction of these hepatic enzymes from TCDD-elicited lethality, but not necessarily hepatic damage, in this species. Furthermore, the hyperthyroidism observed is suggestive of a role of these hormones in the relatively insensitive nature of this species to TCDD treatment.     

Using life-cycle assessments in large corporations: A survey of current practices

Industries presently face a challenge to maintain competitiveness while creating minimal adverse impacts on the environment. The conventional concerns of product functionality, quality, and cost are further complicated by environmental considerations. Thus, corporate environmental strategies are evolving toward a life-cycle approach by implementing life-cycle analysis (LCA), design for environment (DFE), and environmentally conscious design and manufacturing (ECDM) practices. These life-cycle concepts provide a tool for industry to identify and evaluate opportunities to minimize environmental burdens from cradle to grave. A mail survey administered by Vanderbilt University's U.S.-Japan Center for Technology Management was sent to 175 U.S. corporations from the 1994 Fortune 500 list. The results show that more than half of the 56 respondents are using life-cycle concepts for environmental assessments, with marketing and cost issues as the primary motivation factors. Hi-tech and personal care firms are more active in implementing LCAs while chemical and intermediate companies are more involved with maintaining databases and utilizing LCA tools. The survey and this article show how life-cycle thinking has not been adequately integrated throughout corporate organizations, and most environmental efforts are initiated by the environmental affairs department. However, the percentage of top management involvement has increased since 1992 and is now at moderate levels. LCA methods need to be further developed in order to expand their industrial acceptability.     

Predicting turnover: A comparison of part-time and full-time employees

The predictability of turnover was compared for part-time versus full-time workers. This was accomplished using variables (1) that were hypothesized by Mobley (1977) to precede the turnover decision and (2) that have been shown in previous research to be significantly related to turnover. Measures of these variables were assessed via questionnaires following the second month of employment. Turnover was assessed directly from company records for a period of up to twelve months following employment. None of the hypothesized antecedent variables were significantly related to turnover within the part-time group. However, within the full-time group, all of the hypothesized precursors to turnover were found to be at least marginally related to actual turnover. Further, there was evidence to suggest differential predictability of turnover across full-time and part-time employment status groups, suggesting that the two groups may have a different ‘psychology of work’. These results are discussed in terms of the supportive evidence provided.     

MISSOURI RIVER - THE NEW COMPACTING GAME1

ABSTRACT: This paper addresses the recent interest in management of the Missouri River. Interstate issues in the river basin include interbasin water diversions, riverbed and shoreline degradation, loss of recreational and natural areas, reduction in navigation capacity, the status of the Pick-Sloan Missouri Basin Program in terms of general river development, and the elimination of river basin commissions, An attempt to develop a comprehensive interstate water compact failed in the 1950s. The new efforts towards establishing a compact are discussed, as well as other available mechanisms for resolution of the current political and legal differences among the ten river basin states.     

The mentor advantage: Perceived career/job experiences of proteges versus non-proteges

Do proteges report having more positive job/career experiences than non-proteges? Do male proteges report having more favorable job/career experiences than female proteges? Do high-level proteges report having more favourable work experiences than low-level proteges? To answer these questions, mentored and non-mentored men and women in high- and low-level positions were asked to evaluate, on a survey questionnaire, their level of satisfaction, career mobility/opportunity, recognition, security and promotion rate. The extent to which these career/job experiences varied as a function of their mentored status, sex and organizational level was examined. The results of the study revealed that mentored individuals reported having more satisfaction, career mobility/opportunity, recognition and a higher promotion rate than non-mentored individuals. However, proteges' perceptions of their job/career situations were not affected by their sex or level. Whether systematic differences exist in the experience of being mentored has yet to be examined.     

Female mate choice in the non-territorial lizard Ameiva plei (Teiidae)

Mate choice by females has been documented in a variety of taxa. Female mate choice in species lacking male resource control or paternal care might occur if preferred males provide protection from harassment. Female mate choice was investigated in a natural population of the non-territorial lizard Ameiva plei (Teiidae). Consort pairs were allowed to form naturally. Consort males were significantly larger than non-consort males. After removal of consort males, the “abandoned” female's reaction to the first male who approached her was recorded. Females rejected all small males. Female preference for large males was significantly higher than preference for small males. Large males may be better equipped to guard the females from harassment and behavior of large males is less harassing than behavior of small males, thereby affording the female increased foraging time. Received: 21 June 1996 / Accepted after revision: 28 December 1996     

Power and Sample Size Calculations for Linear Hypotheses Associated with Mixtures of Many Components using Fixed-Ratio Ray Designs

Response surface methodology, often supported by factorial designs, is the classical experimental approach that is widely accepted for detecting and characterizing interactions among chemicals in a mixture. In an effort to reduce the experimental effort as the number of compounds under study is increased, ray designs have been proposed to study combinations of chemicals. When interest is restricted to relevant mixing ratios, we are only interested in making inference along the specific rays of interest, as opposed to methods which use designs that require more experimental effort to support the estimation of a response surface over a broader experimental region. Methods have been developed for the test of additivity along multiple fixed-ratio rays. Of primary importance is the detection of interactions with reasonable power. The objective of this paper is to address power and sample size issues related to the hypothesis of no interaction.     

2,4,6-Trinitrotoluene detection using recombinant antibodies

The ability to detect low levels of 2,4,6-trinitrotoluene (TNT) in aqueous samples is important due to the toxicity of both TNT and its breakdown products. We have been characterizing recombinant anti-TNT antibodies isolated from the Griffin library of phage displayed scFvs by selection for binders to the TNT-surrogate 2,4,6-trinitrobenzene (TNB) coupled to the protein bovine serum albumin. Two candidate antibody fragments, TNB1 and TNB2, were isolated and evaluated by ELISA for their ability to bind to TNB coupled to the protein ovalbumin. Competition ELISA was then used to demonstrate antibody fragment binding to TNT in solution and to examine cross-reactivity towards several TNT-related compounds and other explosives. Both recombinant antibody fragments were incorporated into a continuous flow assay for the detection of TNT. TNB2, the best single chain antibody, showed a limit of detection of 1 ng ml(-1), comparable to a commercially available anti-TNT antibody in the same assay format.