The roles of incentives and voluntary cooperation for contractual compliance

Efficiency under contractual incompleteness often requires voluntary cooperation in situations where self-regarding incentives for contractual compliance are present as well. Here we provide a comprehensive experimental analysis based on the gift-exchange game of how explicit and implicit incentives affect cooperation. We first show that there is substantial cooperation under non-incentive compatible contracts. Incentive-compatible contracts induce best-reply effort and crowd out any voluntary cooperation. Further experiments show that this result is robust to two important variables: experiencing Trust contracts without any incentives and implicit incentives coming from repeated interaction. Implicit incentives have a strong positive effect on effort only under non-incentive compatible contracts.principal-agent games; gift-exchange experiments; incomplete contracts, explicit incentives; implicit incentives; repeated games; separability; experiments

The Roles of Incentives and Voluntary Cooperation for Contractual Compliance

Efficiency under contractual incompleteness often requires voluntary cooperation in situations where self-regarding incentives for contractual compliance are present as well. Here we provide a comprehensive experimental analysis based on the gift-exchange game of how explicit and implicit incentives affect cooperation. We first show that there is substantial cooperation under non-incentive compatible contracts. Incentive-compatible contracts induce best-reply effort and crowd out any voluntary cooperation. Further experiments show that this result is robust to two important variables: experiencing Trust contracts without any incentives and implicit incentives coming from repeated interaction. Implicit incentives have a strong positive effect on effort only under non-incentive compatible contracts.principal-agent games, gift-exchange experiments, incomplete contracts, explicit incentives, implicit incentives, repeated games, separability, experiments

Preparation and Catalytic Activity of Boron-Substituted Zirconocenes

Borylated zirconocenes of the type (L2B–C5H4)2ZrCl2 and (L2B–C5H4)(C5H5)ZrCl2 are readily available in two steps. In the polymerization of ethylene and propylene in the presence of AlEt3 or methylalumoxan (MAO), these zirconocenes are more active than the unsubstituted reagent Cp2ZrCl2

Expression of PHA polymerase genes of Pseudomonas putida in Escherichia coli and its effect on PHA formation

Poly-3-hydroxyalkanoates (PHAs) are synthesized by many bacteria as intracellular storage material. The final step in PHA biosynthesis is catalyzed by two PHA polymerases (phaC) in Pseudomonas putida. The expression of these two phaC genes (phaC1 and phaC2)was studied in Escherichia coli, either under control of the native promoter or under control of an external promoter. It was found that the two phaC genes are not expressed in E. coli without an external promoter. During heterologous expression of phaC from Plac on a high copy number plasmid, a rapid reduction of the number of colony forming units was observed, especially for phaC2. It appears that the plasmid instability was partially caused by high-level production of PHA polymerase. Subsequently, tightly regulated phaC2 expression systems on a low copy number vector were applied in E. coli. This resulted in PHA yields of over 20 of total cell dry weight, which was 2 fold higher than that obtained from the system where phaC2 is present on a high copy number vector. In addition, the PHA monomer composition differed when different gene expression systems or different phaC genes were applie

Cyclo19,31[D-Cys19]-uPA19-31 is a potent competitive antagonist of the interaction of urokinase-type plasminogen activator with its receptor (CD87)

Urokinase-type plasminogen activator (uPA) represents a central molecule in pericellular proteolysis and is implicated in a variety of physiological and pathophysiological processes such as tissue remodelling, wound healing, tumor invasion, and metastasis. uPA binds with high affinity to a specific cell surface receptor, uPAR (CD87), via a well defined sequence within the N-terminal region of uPA (uPA(19-31)). This interaction directs the proteolytic activity of uPA to the cell surface which represents an important step in tumor cell proliferation, invasion, and metastasis. Due to its fundamental role in these processes, the uPA/uPAR-system has emerged as a novel target for tumor therapy. Previously, we have identified a synthetic, cyclic, uPA-derived peptide, cyclo(19,31)uPA(19-31), as a lead structure for the development of low molecular weight uPA-analogues, capable of blocking uPA/uPAR-interaction {[}Burgle et al., Biol. Chem. 378 (1997), 231-237]. We now searched for peptide variants of cyclo(19,31)uPA(19-31) with elevated affinities for uPAR binding. Among other tasks, we performed a systematic D-amino acid scan of quPA(19-31), in which each of the 13 L-amino acids was individually substituted by the corresponding D-amino acid. This led to the identification of cyclo(19,31) {[}D-Cys(19)]-uPA(19-31) as a potent inhibitor of uPA/uPAR-interaction, displaying only a 20 to 40-fold lower binding capacity as compared to the naturally occurring uPAR-ligands uPA and its amino-terminal fragment. Cyclo(19,31)[D-Cys(19)]-uPA(19-31) not only blocks binding of uPA to uPAR but is also capable of efficiently displacing uPAR-bound uPA from the cell surface and to inhibit uPA-mediated, tumor cell-associated plasminogen activation and fibrin degradation. Thus, cyclo(19,31)[D-Cys(19)]-uPA(19-31) represents a promising therapeutic agent to significantly affect the tumor-associated uPA/uPAR-system

Poly(3-hydroxyalkanoate) polymerase synthesis and in vitro activity in recombinant Escherichia coli and Pseudomonas putida

We tested the synthesis and in vitro activity of the poly(3-hydroxyalkanoate) (PHA) polymerase 1 from Pseudomonas putida GPo1 in both P. putida GPp104 and Escherichia coli JMU193. The polymerase encoding gene phaC1 was expressed using the inducible PalkB promoter. It was found that the production of polymerase could be modulated over a wide range of protein levels by varying inducer concentrations. The optimal inducer dicyclopropylketone concentrations for PHA production were at 0.03% (v/v) for P. putida and 0.005% (v/v) for E. coli. Under these concentrations the maximal polymerase level synthesized in the E. coli host (6% of total protein) was about three- to fourfold less than that in P. putida (20%), whereas the maximal level of PHA synthesized in the E. coli host (8% of total cell dry weight) was about fourfold less than that in P. putida (30%). In P. putida, the highest specific activity of polymerase was found in the mid-exponential growth phase with a maximum of 40U/g polymerase, whereas in E. coli, the maximal specific polymerase activity was found in the early stationary growth phase (2U/g polymerase). Our results suggest that optimal functioning of the PHA polymerase requires factors or a molecular environment that is available in P. putida but not in E. col

Regulation of emotions in the community: suppression and reappraisal strategies and its psychometric properties

Objective: The German Version of the Emotion Regulation Questionnaire (ERQ) has recently been published. The questionnaire investigates two common emotion regulation strategies (10 items) on two scales (suppression, reappraisal). Major aims of the study were to assess the reliability and factor structure of the ERQ, to determine population based norms and to investigate relations of suppression and reappraisal to anxiety, depression and demographic characteristics

Regulation of emotions in the community: suppression and reappraisal strategies and its psychometric properties

Objective: The German Version of the Emotion Regulation Questionnaire (ERQ) has recently been published. The questionnaire investigates two common emotion regulation strategies (10 items) on two scales (suppression, reappraisal). Major aims of the study were to assess the reliability and factor structure of the ERQ, to determine population based norms and to investigate relations of suppression and reappraisal to anxiety, depression and demographic characteristics

results of the sifap1 study

Objectives The present study aimed to evaluate the frequency of warning signs in younger patients with stroke with a special regard to the ‘FAST’ scheme, a public stroke recognition instrument (face, arm, speech, timely). Setting Primary stroke care in participating centres of a multinational European prospective cross-sectional study (Stroke in Young Fabry Patients; sifap1). Forty-seven centres from 15 European countries participate in sifap1. Participants 5023 acute patients with stroke (aged 18–55 years) patients (96.5% Caucasians) were enrolled in the study between April 2007 and January 2010. Primary and secondary outcome measures sifap1 was originally designed to investigate the relation of juvenile stroke and Fabry disease. A secondary aim of sifap1 was to investigate stroke patterns in this specific group of patients. The present investigation is a secondary analysis addressing stroke presenting symptoms with a special regard to signs included in the FAST scheme. Results 4535 patients with transient ischaemic attack (TIA; n=1071), ischaemic stroke (n=3396) or other (n=68) were considered in the presented analysis. FAST symptoms could be traced in 76.5% of all cases. 35% of those with at least one FAST symptom had all three symptoms. At least one FAST symptom could be recognised in 69.1% of 18–24 years-old patients, in 74% of those aged 25–34 years, in 75.4% of those aged 35–44 years, and 77.8% in 45–55 years-old patients. With increasing stroke severity signs included in the FAST scheme were more prevalent (National Institute of Health Stroke Scale, NIHSS15: 100%). Clustering clinical signs according to FAST lower percentages of strokes in the posterior circulation (65.2%) and in patients with TIA (62.3%) were identified. Conclusions FAST may be applied as a useful and rapid tool to identify stroke symptoms in young individuals aged 18–55 years. Especially in patients eligible for thrombolysis FAST might address the majority of individuals

The effects of short-term fasting on quality of life and tolerance to chemotherapy in patients with breast and ovarian cancer: a randomized cross-over pilot study

Background This pilot trial aimed to study the feasibility and effects on quality of life (QOL) and well-being of short-term fasting (STF) during chemotherapy in patients with gynecological cancer. Methods In an individually-randomized cross-over trial patients with gynecological cancer, 4 to 6 planned chemotherapy cycles were included. Thirty-four patients were randomized to STF in the first half of chemotherapies followed by normocaloric diet (group A;n = 18) or vice versa (group B;n = 16). Fasting started 36 h before and ended 24 h after chemotherapy (60 h-fasting period). QOL was assessed by the FACIT-measurement system. Results The chemotherapy-induced reduction of QOL was less than the Minimally Important Difference (MID; FACT-G = 5) with STF but greater than the MID for non-fasted periods. The mean chemotherapy-induced deterioration of total FACIT-F was 10.4 ± 5.3 for fasted and 27.0 ± 6.3 for non-fasted cycles in group A and 14.1 ± 5.6 for non-fasted and 11.0 ± 5.6 for fasted cycles in group B. There were no serious adverse effects. Conclusion STF during chemotherapy is well tolerated and appears to improve QOL and fatigue during chemotherapy. Larger studies should prove the effect of STF as an adjunct to chemotherapy. Trial registration This trial was registered at clinicaltrials.gov: NCT01954836