Oxytocin Effect on Collective Decision Making: A Randomized Placebo Controlled Study

Collective decision making often benefits both the individuals and the group in a variety of contexts. However, for the group to be successful, individuals should be able to strike a balance between their level of competence and their influence on the collective decisions. The hormone oxytocin has been shown to promote trust, conformism and attention to social cues. We wondered if this hormone may increase participants’ (unwarranted) reliance on their partners’ opinion, resulting in a reduction in collective benefit by disturbing the balance between influence and competence. To test this hypothesis we employed a randomized double-blind placebo-controlled design in which male dyads self-administered intranasal oxytocin or placebo and then performed a visual search task together. Compared to placebo, collective benefit did not decrease under oxytocin. Using an exploratory time dependent analysis, we observed increase in collective benefit over time under oxytocin. Moreover, trial-by-trial analysis showed that under oxytocin the more competent member of each dyad was less likely to change his mind during disagreements, while the less competent member showed a greater willingness to change his mind and conform to the opinion of his more reliable partner. This role-dependent effect may be mediated by enhanced monitoring of own and other’s performance level under oxytocin. Such enhanced social learning could improve the balance between influence and competence and lead to efficient and beneficial collaboration.     

A numerical study on hemodynamics in the left coronary bifurcation with normal and hypertension conditions

In this study, a three-dimensional analysis of the non-Newtonian blood flow was carried out in the left coronary bifurcation. The Casson model and hyperelastic and rigid models were used as the constitutive equation for blood flow and vessel wall model, respectively. Physiological conditions were considered first normal and then compliant with hypertension disease with the aim of evaluating hemodynamic parameters and a better understanding of the onset and progression of atherosclerosis plaques in the coronary artery bifurcation. Two-way fluid–structure interaction method applying a fully implicit second-order backward Euler differencing scheme has been used which is performed in the commercial code ANSYS and ANSYS CFX (version 15.0). When artery deformations and blood pressure are associated, arbitrary Lagrangian–Eulerian formulation is employed to calculate the artery domain response using the temporal blood response. As a result of bifurcation, noticeable velocity reduction and backflow formation decrease shear stress and made it oscillatory at the starting point of the LCx branch which caused the shear stress to be less than 1 and 2 Pa in the LCx and the LAD branches, respectively. Oscillatory shear index (OSI) as a hemodynamic parameter represents the increase in residence time and oscillatory wall shear stress. Because of using the ideal 3D geometry and realistic physiological conditions, the values obtained for shear stress are more accurate than the previous studies. Comparing the results of this study with previous clinical investigations shows that the regions with low wall shear stress less than 1.20 Pa and with high OSI value more than 0.3 are in more potential risk to the atherosclerosis plaque development, especially in the posterior after the bifurcation.     

Designing a Highly Efficient Chemical Chaperone System Using Chitosan-Coated Alginate

In the present work we prepared chitosan-coated alginate beads, to use as a chemical chaperone based on the electrostatic interaction between the carboxylate groups of alginate and the ammonium groups of chitosan. This procedure was an attempt for designing a highly efficient chemical chaperone to improve protein stability and refolding. Based on enzyme recovered activity, turbidity, far-UV CD and fluorescence data, alkaline phosphatase can be stabilized and refolded to a higher degree in the presence of alginate capsules compared with unassisted form and was further improved by including chitosan. Finally the maximum yield was obtained when the refolding process was achieved under a well worked out temperature program: incubation of the captured-enzyme for 20 min at 4 °C followed by overnight incubation at 22 °C, which showed that aggregation is a major limitation to refolding.     

The Lean Woman

Objective: In the current obesity epidemic, the ability to remain lean is beginning to be uncommon. Therefore, it was considered of interest to characterize such subjects. Research Methods and Procedures: From a population of premenopausal women (n = 270), all 40 years of age, those with a similar body mass index (BMI) as women at the age of 21 years, born the same year (BMI = 21.1 kg/m²) were selected among nonsmokers and compared with the remaining nonsmoking women. Results: Lean women showed, as expected, low waist-to-hip circumference ratio and abdominal sagittal diameter as well as absence of other disease risk factors. Compared with the remaining women, 17β-estradiol was high and androgens were low, whereas insulin-like growth factor I and thyroid hormones showed no differences. Dihydroepiandrosterone sulfate was lower, whereas cortisol, measured in saliva repeatedly over a day, and adrenocorticotropin hormone were not different. Results from questionnaires indicated higher education and socioeconomic status, frequent sports activities, and better psychosocial adaptation and psychological health. A tetranucleotide repeat polymorphism in the fifth intron of the aromatase P450 gene was longer among the lean (187 base pairs) than the rest of the women. Women with opposite phylogenetic characteristic have a short microsatellite (168 base pairs) in this gene locus. Discussion: Lean, nonsmoking women enjoy an excellent health in not only anthropometric and metabolic factors, but also in neuroendocrine, endocrine, and psychological variables. The endocrine measurements suggest a well-functioning aromatase, which in turn might have a genetic background, contributing to health. The aromatase gene might be important for regulation of body fat mass.     

Biodegradation of dibenzothiophene by thermophilic bacteria

Anaerobic microbial biodegradation of dibenzothiophene (DBT) was studied using thermophilic bacteria obtained from crude oil. A mixed culture was obtained that degraded 98% of DBT at 0.5 mg ml^–1 at 65 °C over 15 days both in the presence and in the absence of Methyl Viologen.     

Anticonvulsant Activity and Toxicity of Essential Oil and Methanolic Extract of Zhumeria majdae Rech, a Unique Iranian Plant in Mice

Drug-resistance and adverse effects of current drugs are the most obstacles in the treatment of epilepsy. In a plan for finding new natural anticonvulsant agents, we studied the anticonvulsant effects of essential oil (ZMEO) and methanolic extract (ZMME) of Zhumeria majdae in pentylene tetrazol (PTZ) and maximal electro-shock (MES) models in mice. Mice received different doses of ZMEO and ZMME, 30?min before induction of chemical and electrical convulsions. Neurotoxicity (movement toxicity and sedation) was evaluated using rota-rod test. The mortality was determined after 24?h following injection of different doses of the ZMEO and ZMME. The obtained results show that ZMEO dose-dependently protected mice from tonic convulsions induced by PTZ and MES with effective doses (ED₅₀) of 0.26 (0.13?C0.39) and 0.27 (0.17?C0.37)?ml/kg respectively. Toxic doses (TD₅₀) in rota-rod test for ZMEO was 0.55 (0.42?C0.70)?ml/kg. ZMME at dose of 2?g/kg decreased tonic convulsions as much as 40?%. For ZMEO, TD₅₀ of 0.55 (0.45?C0.69)?ml/kg was obtained. ZMME significantly decreased the walking time in rota-rod test at dose of 2?g/kg. Lethal dose (LD₅₀) of ZMEO was determined as 2.35 (1.98?C2.65)?ml/kg. ZMME showed about 34?% death of the animals at dose 5?g/kg. The essential oil of Z. majdae could be a good candidate for further anticonvulsive studies.