Impacts on decision making of executives: Probabilities versus outcomes.

The determinants of decision making of executives are of special interest for companies. For a long time choices have been investigated based on theories that assume an equal impact of expected outcomes and expected probabilities (Von Neumann and Morgenstern 1953, Savage 1954, Kahneman and Tversky 1979). The influence of probabilities in decision processes is, however, questioned by a growing body of research (Rottenstreich and Kivetz 2006, Shapira 1995, March and Shapira 1987, 1992). To monitor the information acquisition process of board members and high-ranking executives in the German insurance industry we conducted 51 personal interviews, which included computer-aided simulations. These simulations clearly and objectively support former statements of executives (Shapira 1995) that they focus more on the amount of decision outcomes than on the corresponding probabilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Economical and ecological comparison of granular activated carbon (GAC) adsorber refill strategies

Technical constraints can leave a considerable freedom in the design of a technology, production or service strategy. Choosing between economical or ecological decision criteria then characteristically leads to controversial solutions of ideal systems. For the adaptation of granular-activated carbon (GAC) fixed beds, various technical factors determine the adsorber volume required to achieve a desired service life. In considering carbon replacement and recycling, a variety of refill strategies are available that differ in terms of refill interval, respective adsorber volume, and time-dependent use of virgin, as well as recycled GAC. Focusing on the treatment of contaminant groundwater, we compare cost-optimal reactor configurations and refill strategies to the ecologically best alternatives. Costs and consumption of GAC are quantified within a technical-economical framework. The emissions from GAC production out of hard coal, transport and recycling are equally derived through a life cycle impact assessment. It is shown how high discount rates lead to a preference of small fixed-bed volumes, and accordingly, a high number of refills. For fixed discount rates, the investigation reveals that both the economical as well as ecological assessment of refill strategies are especially sensitive to the relative valuation of virgin and recycled GAC. Since recycling results in economic and ecological benefits, optimized systems thus may differ only slightly.     

Effect of a combination of hexamethylphosphoramide and alkyl alcohol on the stereospecificity of radical polymerization of N-isopropylacrylamide

Radical polymerization of N-isopropylacrylamide (NIPAAm) was investigated at low temperatures in the presence of both hexamethylphosphoramide (HMPA) and alkyl alcohols. Although HMPA and alkyl alcohols separately induced syndiotactic specificity in NIPAAm polymerization in toluene at low temperatures, a combination of HMPA and less bulky alkyl alcohols, such as methanol and ethanol, was found to induce isotactic specificity at −80 °C. NMR analysis of mixtures of NIPAAm, ethanol and HMPA suggested the formation of a 1:1:1 complex through O-H•••O=C and N-H•••O=P hydrogen bonding. It is believed that the steric effect of HMPA enhanced by cooperative hydrogen bonding was responsible for the combined effect of HMPA and alkyl alcohols in inducing isotactic specificity.     

Is age-related stability of subjective well-being a paradox? Cross-sectional and longitudinal evidence from the Berlin Aging Study.

Subjective well-being is thought to remain relatively stable into old age despite health-related losses. Age and functional health constraints were examined as predictors of individual differences and intraindividual change in subjective well-being, as indicated by positive and negative affect, using cross-sectional (N?=?516) and longitudinal (N?=?203) samples from the Berlin Aging Study (age range 70–103 years). In cross-sectional and longitudinal analyses, age and functional health constraints were negatively related to positive affect but unrelated to negative affect. Cross-sectionally, controlling for functional health constraints reversed the direction of the relationship between age and positive affect and produced a negative association between age and negative affect. Findings suggest two qualifications to the average stability of overall subjective well-being: Only some dimensions of subjective well-being remain stable, while others decline; age per se is not a cause of decline in subjective well-being but health constraints are. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Temperature distribution in an array of moving cracks acting as heat sinks

The temperature distribution in a periodic array of parallel cracks acting as heat sinks is studied for the case of stationary crack motion by use of the Wiener–Hopf method. The problem arises in the investigation of cracks propagating into solid material, where the stresses driving crack motion are caused by heat transfer from the solid through the crack surfaces. The solution is given in terms of Fourier integrals involving infinite products. The heat-flux distribution in the vicinity of the crack tips is computed analytically from the high wavenumber asymptotics. Numerical solutions of the temperature distribution are presented for several values of the Biot and Péclet number, and the effect of varying these parameters is discussed qualitatively.     

Measurement of prolonged fatigue in the working population: Determination of a cutoff point for the Checklist Individual Strength.

In the Netherlands, a large-scale prospective cohort study was started on prolonged fatigue in the working population. The 1st issue that had to be addressed was the determination of a cutoff point for fatigue for use in the working population. Fatigue is measured with the Checklist Individual Strength (CIS), a 20-item self-report questionnaire. This article demonstrates the process of decision making in the determination of the cutoff point. Total CIS scores were calculated, sensitivity and specificity were compared for potential cutoff points, and a receiver operating characteristics analysis was conducted. A CIS total cutoff point for fatigue of >76 was determined, with a specificity of 90% and a sensitivity of 73%. Limitations regarding the use of cutoff points are discussed. It is concluded that the defined cutoff point seems to be appropriate for use in the working population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Investigations on the change of fumonisin content of maize during hydrothermal treatment of maize. Analysis by means of HPLC methods and ELISA

The study was subjected to the investigation of the effects of extrusion cooking, gelatinization, and cornflaking on the stability of fumonisins in artificially contaminated maize grits, spiked with fumonisin B₁ and B₂ at levels of 2 mg/kg and 0.6 mg/kg, respectively. All the processed samples were analyzed according to the AOAC-HPLC method, and some selected samples were analyzed additionally by a commercial enzyme-linked immunosorbent assay (ELISA) and after alkaline hydrolysis. All the samples showed significant decreases of the fumonisin levels. If analyzed according to AOAC-HPLC method, cooking extrusion and gelatinization reduced fumonisin levels to approximately 30-55%, cooking the grits for flaking to approximately 20-65%, and roasting the flakes to approximately 6-35% (depending on the selected technological parameters). With ELISA the fumonisin contents were 15-50% and after alkaline hydrolysis 19-380% higher than with the AOAC-HPLC method. However, the fumonisin amount added before the technological tests could not be recovered in any of the samples.     

Tuning the phase of circadian entrainment

The circadian clock coordinates daily physiological, metabolic and behavioural rhythms. These endogenous oscillations are synchronized with external cues (‘zeitgebers’), such as daily light and temperature cycles. When the circadian clock is entrained by a zeitgeber, the phase difference ψ between the phase of a clock-controlled rhythm and the phase of the zeitgeber is of fundamental importance for the fitness of the organism. The phase of entrainment ψ depends on the mismatch between the intrinsic period τ and the zeitgeber period T and on the ratio of the zeitgeber strength to oscillator amplitude. Motivated by the intriguing complexity of empirical data and by our own experiments on temperature entrainment of mouse suprachiasmatic nucleus (SCN) slices, we present a theory on how clock and zeitgeber properties determine the phase of entrainment. The wide applicability of the theory is demonstrated using mathematical models of different complexity as well as by experimental data. Predictions of the theory are confirmed by published data on Neurospora crassa strains for different period mismatches τ − T and varying photoperiods. We apply a novel regression technique to analyse entrainment of SCN slices by temperature cycles. We find that mathematical models can explain not only the stable asymptotic phase of entrainment, but also transient phase dynamics. Our theory provides the potential to explore seasonal variations of circadian rhythms, jet lag and shift work in forthcoming studies.     

Trans-Cinnamic Acid Increases Adiponectin and the Phosphorylation of AMP-Activated Protein Kinase through G-Protein-Coupled Receptor Signaling in 3T3-L1 Adipocytes

Adiponectin and intracellular 5′adenosine monophosphate-activated protein kinase (AMPK) are important modulators of glucose and fat metabolism. Cinnamon exerts beneficial effects by improving insulin sensitivity and blood lipids, e.g., through increasing adiponectin concentrations and AMPK activation. The underlying mechanism is unknown. The G_i/G_o-protein-coupled receptor (GPR) 109A stimulates adiponectin secretion after binding its ligand niacin. Trans-cinnamic acid (tCA), a compound of cinnamon is another ligand. We hypothesize whether AMPK activation and adiponectin secretion by tCA is transmitted by GPR signaling. Differentiated 3T3-L1 cells were incubated with pertussis toxin (PTX), an inhibitor of G_i/G_o-protein-coupling, and treated with different tCA concentrations. Treatment with tCA increased adiponectin and the pAMPK/AMPK ratio (p ≤ 0.001). PTX incubation abolished the increased pAMPK/AMPK ratio and adiponectin secretion. The latter remained increased compared to controls (p ≤ 0.002). tCA treatment stimulated adiponectin secretion and AMPK activation; the inhibitory effect of PTX suggests GPR is involved in tCA stimulated signaling.