Does contact reduce prejudice or does prejudice reduce contact? A longitudinal test of the contact hypothesis among majority and minority groups in three european countries.

A widely researched panacea for reducing intergroup prejudice is the contact hypothesis. However, few longitudinal studies can shed light on the direction of causal processes: from contact to prejudice reduction (contact effects) or from prejudice to contact reduction (prejudice effects). The authors conducted a longitudinal field survey in Germany, Belgium, and England with school students. The sample comprised members of both ethnic minorities (n = 512) and ethnic majorities (n = 1,143). Path analyses yielded both lagged contact effects and prejudice effects: Contact reduced prejudice, but prejudice also reduced contact. Furthermore, contact effects were negligible for minority members. These effects were obtained for 2 indicators of prejudice: negative intergroup emotions and desire for social distance. For both majority and minority members, contact effects on negative emotions were stronger when outgroup contacts were perceived as being typical of their group. Contact effects were also mediated by intergroup anxiety. This mediating mechanism was impaired for minority members because of a weakened effect of anxiety on desire for social distance. Theoretical and practical implications of these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Loss aversion and price volatility as determinants of attitude towards and preference for variable price in the Swedish electricity market

The results of a survey of a random sample of 488 Swedish residents showed that a positive attitude towards and preference for a variable price agreement with the incumbent electricity supplier was negatively affected by loss aversion, and a positive attitude also negatively affected by beliefs about price volatility. Although correlated with attitude and preference, age, education, and current choice of a variable price agreement had no independent effects. Income and current electricity costs had no effects.     

A native chemical ligation approach for combinatorial assembly of affibody molecules

Affinity molecules labeled with different reporter groups, such as fluorophores or radionuclides, are valuable research tools used in a variety of applications. One class of engineered affinity proteins is Affibody molecules, which are small (6.5 kDa) proteins that can be produced by solid phase peptide synthesis (SPPS), thereby allowing site-specific incorporation of reporter groups during synthesis. The Affibody molecules are triple-helix proteins composed of a variable part, which gives the protein its binding specificity, and a constant part, which is identical for all Affibody molecules. In the present study, native chemical ligation (NCL) has been applied for combinatorial assembly of Affibody molecules from peptide fragments produced by Fmoc SPPS. The concept is demonstrated for the synthesis of three different Affibody molecules. The cysteine residue introduced at the site of ligation can be used for directed immobilization and does not interfere with the function of the investigated proteins. This strategy combines a high-yield production method with facilitated preparation of proteins with different C-terminal modifications.     

Photonic crystal patterning of luminescent sol-gel films for light extraction

Structured luminescent thin films are investigated in the context of improved light extraction of phosphors for solid-state-lighting applications. Thin films composed of a sol-gel titania matrix doped with europium chelates are studied as a model system. These films, patterned with a square photonic lattice by soft nanoimprint lithography, are characterized by angle-resolved fluorescence. Modeling of this simple technique is shown to fit well the experimental data, revealing in great detail the guided modes of the film and their extraction parameters. An eightfold extraction enhancement factor of the film emission is measured. To further improve the extraction efficiency, we investigate the role of an additional low-index mesoporous silica underlayer through its influence on the guided modes of different polarizations and their interactions with the photonic crystal. Results obtained on model systems open the way towards the optimization of light-emitting devices, using a strategy of dielectric microstructure engineering using the sol-gel process.     

Cyclic volatile methylsiloxane bioaccumulation in flounder and ragworm in the Humber Estuary

Cyclic volatile methylsiloxanes are being subjected to regulatory scrutiny as possible PBT chemicals. The investigation of bioaccumulation has yielded apparently contradictory results, with high laboratory fish bioconcentration factors on the one hand and low field trophic magnification factors on the other. In this study, octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) were studied along with polychlorinated biphenyls (PCBs) in sediments, ragworm, and flounder from six sites in the Humber Estuary. Bioaccumulation was evaluated using multimedia bioaccumulation factors (mmBAFs) which quantified the fraction of the contaminant present in the aquatic environment that is transferred to the biota. PCB 180, a known strongly bioaccumulative chemical, was used as a benchmark. The mean mmBAF of D5 was about twice that of PCB 180 in both polycheates and flounder, while for D4 it was 6 and 14 times higher, respectively. The mmBAF of D6 was a factor 5-10 lower than that of PCB180. The comparatively strong multimedia bioaccumulation of D4 and D5, even in the absence of biomagnification, was explained by both compounds having a >100 times stronger tendency to partition into lipid rather than into organic carbon, while PCB 180 partitions to a similar extent into both matrices.     

Discovery and Characterization of ACT‐451840: an Antimalarial Drug with a Novel Mechanism of Action

More than 40 % of the world's population is at risk of being infected with malaria. Most malaria cases occur in the countries of sub‐Saharan Africa, Central and South America, and Asia. Resistance to standard therapy, including artemisinin combinations, is increasing. There is an urgent need for novel antimalarials with new mechanisms of action. In a phenotypic screen, we identified a series of phenylalanine‐based compounds that exhibit antimalarial activity via a new and yet unknown mechanism of action. Our optimization efforts culminated in the selection of ACT‐451840 [(S,E)‐N‐(4‐(4‐acetylpiperazin‐1‐yl)benzyl)‐3‐(4‐(tert‐butyl)phenyl)‐N‐(1‐(4‐(4‐cyanobenzyl)piperazin‐1‐yl)‐1‐oxo‐3‐phenylpropan‐2‐yl)acrylamide] for clinical development. Herein we describe our optimization efforts from the screening hit to the potential drug candidate with respect to antiparasitic activity, drug metabolism and pharmacokinetics (DMPK) properties, and in vivo pharmacological efficacy.     

Robustness and sensitivity of a blueprint for on-farm estimation of dairy cow energy balance

Excessive negative energy balance (EB) has been associated with decreased reproductive performance and increased risk of lameness and metabolic diseases. On-farm, automated EB estimates for individual cows would enable dairy farmers to detect excessive negative EB early and act to minimize its extent and duration by altering feeding. Previously, we have shown that EB can be estimated from frequent measurements of body weight (BW) and body condition score (BCS) changes, referred to as EB_body. In this study, we investigated the robustness and sensitivity of the EB_body method to assess its genericity and on-farm applicability. We used 5 data sets with BW of lactating cows (name of data set in parenthesis): 65 Holstein cows in a French feeding trial (INRA); 6 Holstein cows in a British feeding trial (Friggens); 31 Holstein cows and 17 Jersey cows in a Danish feeding trial (DCRC); 140 Holstein cows in a British feeding trial (Scotland's Rural College, SRUC); and 1,592 Holstein cows on 9 Danish farms with milking robots (automatic milking system). We used the INRA and Friggens data sets to develop a dynamic formula to correct BW for increasing residual gut-fill (RGF) during early lactation. With the DCRC data, we tested the effect of smoothing parameters and weighing frequency on EB_body. Also, 2 robustness tests were performed using the SRUC data to test the effect of diet change on BW and the automatic milking system data to test the effect of farm on BW variation. Finally, we combined the results into a blueprint describing different ways to calculate EB_body depending on the purpose and on the availability of BCS. The dynamic RGF adjustment resulted in a lower empty BW during early lactation than that obtained with the previously used constant RGF. The double-exponential smoothing method used to correct for meal-related gut-fill was robust to choice of smoothing parameters. Cows should be weighed at least once every 4 d during early lactation to capture the duration of negative EB_body. Our EB_body method proved robust to diet changes. Finally, although cow BW varied significantly between farms, the quantile regression smoothing of BW did not bias the estimation of weight differences between herds. In conclusion, these results validate the applicability of the EB_body method to estimate EB across a range of farm conditions, and we provided a blueprint that enables the estimation of EB_body for individual cows on-farm using only frequent BW, in combination with BCS when available.     

Learning the value of money from stochastically varying prices.

In 3 experiments, the authors investigated learning of the value of money from product prices in an unfamiliar currency when the prices are proportional to quantity. In support of the second stage of a hypothesized 2-stage process of learning, Experiment 1, in which 32 undergraduates participated, shows that response times for inferences of quantity are longer when participants are presented with quantity-price pairs than when they are presented with price-quantity pairs. Experiments 2 and 3, in which 54 and 34 undergraduates participated, respectively, show that (a) stochastic price variation causes systematic errors in the learning of unit prices from quantity-price pairs as a result of judgmental regression effects and (b) in support of the 2-stage learning hypothesis, inferences of quantity are the inverse of the learned unit prices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)