1,795 research outputs found

    Fluorescence of Naphthol AS-MX is Readily Detectable in Dioxane Mixtures

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    Numerous enzymes have been demonstrated to be active in non-aqueous solutions, yet the utility of phosphatases under such conditions has been difficult to determine. Here, we demonstrate the ability to fluorescently detect naphthol AS‑MX in high percentages 1,4-dioxane with a fluorescence differential compared with naphthol AS‑MX phosphate. While intensities and maximum fluorescence wavelengths changed depending on solvent conditions, these results demonstrate this system’s potential for testing phosphatase activity in high amounts of dioxane

    Is Schr\"{o}dinger's Conjecture for the Hydrogen Atom Coherent States Attainable

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    We construct the most general SO(4,2) hydrogen atom coherent states which are the counterpart of Schr\"{o}dinger's harmonic oscillator coherent states. We show that these states cannot be localized and cannot follow the classical orbits. Thus, Schr\"{o}dinger's conjecture for the hydrogen atom coherent states is unattainable.Comment: 10 pages, report

    Temporal Variability of Organic C and Nitrate in a Shallow Aquifer

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    The loading of organic substrates into shallow aquifers may follow seasonal cycles, which will impact the transport and fate of agrichemicals. The objective of this research was to measure temporal changes in the groundwater dissolved organic C (DOC) and nitrate concentrations. Groundwater monitoring wells were installed and sediment samples from the aquifer were collected in 1991. Sediment samples were used to evaluate denitrification potentials, while water samples were collected at periodic intervals in 1992 and 1993 from the surface of the aquifer. Water samples were analyzed for nitrate-N and DOC-C. Denitrification was observed in sediment amended with nitrate and incubated under anaerobic conditions at 10°C. Addition of algae lazed biomass increased denitrification, establishing that denitrification was substrate limited. In the aquifer, DOC concentrations followed seasonal patterns. DOC concentrations were highest following spring recharge and then decreased. Peak timing indicates that freezing and thawing were responsible for seasonal DOC patterns. These findings show that seasonally driven physical processes, such as freezing and thawing, influence organic substrate transport from surface to subsurface environments, and that this process should be taken into account when assessing agrichemical detoxification rates in shallow aquifers

    Using self-definition to predict the influence of procedural justice on organizational, interpersonal, and job/task-oriented citizenship behaviors

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    An integrative self-definition model is proposed to improve our understanding of how procedural justice affects different outcome modalities in organizational behavior. Specifically, it is examined whether the strength of different levels of self-definition (collective, relational, and individual) each uniquely interact with procedural justice to predict organizational, interpersonal, and job/task-oriented citizenship behaviors, respectively. Results from experimental and (both single and multisource) field data consistently revealed stronger procedural justice effects (1) on organizational-oriented citizenship behavior among those who define themselves strongly in terms of organizational characteristics, (2) on interpersonal-oriented citizenship behavior among those who define themselves strongly in terms of their interpersonal relationships, and (3) on job/task-oriented citizenship behavior among those who define themselves weakly in terms of their distinctiveness or uniqueness. We discuss the relevance of these results with respect to how employees can be motivated most effectively in organizational settings

    Manganese superoxide dismutase Ala-9Val polymorphism and risk of breast cancer in a population-based case–control study of African Americans and whites

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    INTRODUCTION: A polymorphism in the manganese superoxide dismutase (MnSOD) gene, Ala-9Val, has been examined in association with breast cancer risk in several epidemiologic studies. Results suggest that the Ala allele increases the risk of breast cancer and modifies the effects of environmental exposures that produce oxidative damage to DNA. METHODS: We examined the role of the MnSOD Ala-9Val polymorphism in a population-based case–control study of invasive and in situ breast cancer in North Carolina. Genotypes were evaluated for 2025 cases (760 African Americans and 1265 whites) and for 1812 controls (677 African Americans and 1135 whites). RESULTS: The odds ratio for MnSOD Ala/Ala versus any MnSOD Val genotypes was not elevated in African Americans (odds ratio = 0.9, 95% confidence interval = 0.7–1.2) or in whites (odds ratio = 1.0, 95% confidence interval = 0.8–1.2). Greater than additive joint effects were observed for the Ala/Ala genotype and smoking, radiation to the chest, and occupational exposure to ionizing radiation. Antagonism was observed between the Ala/Ala genotype and the use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: The MnSOD genotype may contribute to an increased risk of breast cancer in the presence of specific environmental exposures. These results provide further evidence for the importance of reactive oxygen species and of oxidative DNA damage in the etiology of breast cancer

    Willing and able: action-state orientation and the relation between procedural justice and employee cooperation

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    Existing justice theory explains why fair procedures motivate employees to adopt cooperative goals, but it fails to explain how employees strive towards these goals. We study self-regulatory abilities that underlie goal striving; abilities that should thus affect employees’ display of cooperative behavior in response to procedural justice. Building on action control theory, we argue that employees who display effective self-regulatory strategies (action oriented employees) display relatively strong cooperative behavioral responses to fair procedures. A multisource field study and a laboratory experiment support this prediction. A subsequent experiment addresses the process underlying this effect by explicitly showing that action orientation facilitates attainment of the cooperative goals that people adopt in response to fair procedures, thus facilitating the display of actual cooperative behavior. This goal striving approach better integrates research on the relationship between procedural justice and employee cooperation in the self-regulation and the work motivation literature. It also offers organizations a new perspective on making procedural justice effective in stimulating employee cooperation by suggesting factors that help employees reach their adopted goals
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