Social setting,intuition and experience in laboratory experiments interact to shape cooperative decision-making

Recent studies suggest that cooperative decision-making in one-shot interactions is a history-dependent dynamic process: promoting intuition versus deliberation typically has a positive effect on cooperation (dynamism) among people living in a cooperative setting and with no previous experience in economic games on cooperation (history dependence). Here, we report on a laboratory experiment exploring how these findings transfer to a non-cooperative setting. We find two major results: (i) promoting intuition versus deliberation has no effect on cooperative behaviour among inexperienced subjects living in a non-cooperative setting; (ii) experienced subjects cooperate more than inexperienced subjects, but only under time pressure. These results suggest that cooperation is a learning process, rather than an instinctive impulse or a self-controlled choice, and that experience operates primarily via the channel of intuition. Our findings shed further light on the cognitive basis of human cooperative decision-making and provide further support for the recently proposed social heuristics hypothesis.     

Nox2 B-loop peptide, Nox2ds, specifically inhibits the NADPH oxidase Nox2

In recent years, reactive oxygen species (ROS) derived from the vascular isoforms of NADPH oxidase, Nox1, Nox2, and Nox4, have been implicated in many cardiovascular pathologies. As a result, the selective inhibition of these isoforms is an area of intense current investigation. In this study, we postulated that Nox2ds, a peptidic inhibitor that mimics a sequence in the cytosolic B-loop of Nox2, would inhibit ROS production by the Nox2-, but not the Nox1- and Nox4-oxidase systems. To test our hypothesis, the inhibitory activity of Nox2ds was assessed in cell-free assays using reconstituted systems expressing the Nox2-, canonical or hybrid Nox1-, or Nox4-oxidase. Our findings demonstrate that Nox2ds, but not its scrambled control, potently inhibited superoxide (O₂^•−) production in the Nox2 cell-free system, as assessed by the cytochrome c assay. Electron paramagnetic resonance confirmed that Nox2ds inhibits O₂^•− production by Nox2 oxidase. In contrast, Nox2ds did not inhibit ROS production by either Nox1- or Nox4-oxidase. These findings demonstrate that Nox2ds is a selective inhibitor of Nox2-oxidase and support its utility to elucidate the role of Nox2 in organ pathophysiology and its potential as a therapeutic agent.     

Engineering of 2-Cys peroxiredoxin for enhanced stress-tolerance

A typical 2-cysteine peroxiredoxin (2-Cys Prx)-like protein (PpPrx) that alternatively acts as a peroxidase or a molecular chaperone in Pseudomonas putida KT2440 was previously characterized. The dual functions of PpPrx are regulated by the existence of an additional Cys(112) between the active Cys(51) and Cys(171) residues. In the present study, additional Cys residues (Cys(31), Cys(112), and Cys(192)) were added to PpPrx variants to improve their enzymatic function. The optimal position of the additional Cys residues for the dual functionality was assessed. The peroxidase activities of the S31C and Y192C mutants were increased 3- to 4-fold compared to the wild-type, while the chaperone activity was maintained at > 66% of PpPrx. To investigate whether optimization of the dual functions could enhance stress-tolerance in vivo, a complementation study was performed. The S31C and Y192C mutants showed a much greater tolerance than other variants under a complex condition of heat and oxidative stresses. The optimized dual functions of PpPrx could be adapted for use in bioengineering systems and industries, such as to develop organisms that are more resistant to extreme environments.     

Maintenance of syntenic groups between Cathartidae and Gallus gallus indicates symplesiomorphic karyotypes in new world vultures

Similarities between New World and Old World vultures have been interpreted to reflect a close relationship and to suggest the inclusion of both in Accipitridae (Falconiformes). However, deeper analyses indicated that the placement of the New World vultures (cathartids) in this Order is uncertain. Chromosome analysis has shown that cathartids retained a karyotype similar to the putative avian ancestor. In order to verify the occurrence of intrachromosomal rearrangements in cathartids, we hybridized whole chromosome probes of two species (Gallus gallus and Leucopternis albicollis) onto metaphases of Cathartes aura. The results showed that not only were the syntenic groups conserved between Gallus and C. aura, but probably also the general gene order, suggesting that New World vultures share chromosomal symplesiomorphies with most bird lineages.     

Recording Large-scale Neuronal Ensembles with Silicon Probes in the Anesthetized Rat

Large scale electrophysiological recordings from neuronal ensembles offer the opportunity to investigate how the brain orchestrates the wide variety of behaviors from the spiking activity of its neurons. One of the most effective methods to monitor spiking activity from a large number of neurons in multiple local neuronal circuits simultaneously is by using silicon electrode arrays^1-3.Action potentials produce large transmembrane voltage changes in the vicinity of cell somata. These output signals can be measured by placing a conductor in close proximity of a neuron. If there are many active (spiking) neurons in the vicinity of the tip, the electrode records combined signal from all of them, where contribution of a single neuron is weighted by its ''electrical distance''. Silicon probes are ideal recording electrodes to monitor multiple neurons because of a large number of recording sites (+64) and a small volume. Furthermore, multiple sites can be arranged over a distance of millimeters, thus allowing for the simultaneous recordings of neuronal activity in the various cortical layers or in multiple cortical columns (Fig. 1). Importantly, the geometrically precise distribution of the recording sites also allows for the determination of the spatial relationship of the isolated single neurons⁴. Here, we describe an acute, large-scale neuronal recording from the left and right forelimb somatosensory cortex simultaneously in an anesthetized rat with silicon probes (Fig. 2).     

双联抗血小板治疗急性冠脉综合征临床疗效观察

目的:探讨双联抗血小板治疗急性冠脉综合征(ACS)的临床疗效和安全性。方法:60例ACS患者随机分为治疗组和对照组。对照组给予阿司匹林单抗血小板治疗,治疗组采用阿司匹林+氯吡格雷双联抗血小板治疗,治疗3个月后评价临床疗效。结果:治疗组临床疗效总有效率为93.3%,显著高于对照组(76.7%),相比较有显著性差异(P<0.05);治疗后,两组LVEF、CO、E/A显著上升,与治疗前比较均有显著性差异(P<0.05);且治疗组与对照组比较有显著性差异(P<0.05)。结论:阿司匹林和氯吡格雷双联抗血小板药物治疗ACS,可以强化对血小板聚集的抑制,并增强抗栓效果,值得临床应用。     

A Synthesis of New Rigid Fluorescent Bichromophoric Probes for Studying Mechanisms of Donor-Donor Energy Migration

Three new fluorescent probes were synthesized for improving the method of studying donor-donor energy migration (DDEM). Each probe has two identical fluorescent 7-diethylaminocoumarin-3-carbonyl groups attached to a rigid bisteroid dodecacyclic spacer through additional inserts. In two probes, the inserts are β-Ala and L-Ser residues, which provide for a different nearest environment of the fluorophores. The third probe has identical β-Ala inserts.__________Translated from Bioorganicheskaya Khimiya, Vol. 31, No. 3, 2005, pp. 331–334.Original Russian Text Copyright © 2005 by Boldyrev, Molotkovsky.     

Effects of fluorescent dyes, quenchers, and dangling ends on DNA duplex stability

Single and dual-labeled fluorescent oligodeoxynucleotides are used in many molecular biology applications. We investigated the effects of commonly used fluorescent dyes and quenchers on the thermodynamic stability of a model probe-target DNA duplex. We demonstrate that those effects can be significant. Fluorescent dyes and quenchers were attached to the probe ends. In certain combinations, these groups stabilized the duplex up to 1.8kcal/mol and increased T(m) up to 4.3 degrees C. None of the groups tested significantly destabilized the duplex. Rank order of potency was, starting with the most stabilizing group: Iowa Black RQ approximately Black Hole 2>Cy5 approximately Cy3>Black Hole 1>QSY7 approximately Iowa Black FQ>Texas Red approximately TAMRA>FAM approximately HEX approximately Dabcyl>TET. Longer linkers decreased stabilizing effects. Hybridizations to targets with various dangling ends were also studied and were found to have only minor effects on thermodynamic stability. Depending on the dye/quencher combination employed, it can be important to include thermodynamic contributions from fluorophore and quencher when designing oligonucleotide probe assays.     

19F NMR measurements of NO production in hypertensive ISIAH and OXYS rats

Recently we demonstrated the principal possibility of application of 19F NMR spin-trapping technique for in vivo *NO detection [Free Radic. Biol. Med. 36 (2004) 248]. In the present study, we employed this method to elucidate the significance of *NO availability in animal models of hypertension. In vivo *NO-induced conversion of the hydroxylamine of the fluorinated nitronyl nitroxide (HNN) to the hydroxylamine of the iminonitroxide (HIN) in hypertensive ISIAH and OXYS rat strains and normotensive Wistar rat strain was measured. Significantly lower HIN/HNN ratios were measured in the blood of the hypertensive rats. The NMR data were found to positively correlate with the levels of nitrite/nitrate evaluated by Griess method and negatively correlate with the blood pressure. In comparison with other traditionally used methods 19F NMR spectroscopy allows in vivo evaluation of *NO production and provides the basis for in vivo *NO imaging.     

Resolution of Cys and Lys labeling of alpha-crystallin with site-sensitive fluorescent 3-hydroxyflavone dye

Ratiometric fluorescent probes based on 3-hydroxyflavone (3HF) are highly sensitive tools for studying polarity, hydration, electronic polarizability, and electrostatics in different microheterogeneous systems, including protein molecules. In the present work, a reactive derivative of 3HF, 6-bromomethyl-4'-diethylamino-3-hydroxyflavone, recently synthesized in our group, was applied to label covalently bovine lens alpha-crystallin. The labeling of SH and NH(2) groups are clearly distinguished by spectroscopic criteria. We observe that the NH(2) labeling creates the positive charge in the proximity to fluorophore, which results in strong internal Stark effect producing the shift in excitation spectrum by ca. 15 nm. Analysis of excitation-dependent fluorescence spectra allows separation of the emission profiles of these SH- and NH(2)-labeled species. Applying recently developed multiparametric analysis of the obtained emission spectra, we described the physicochemical properties of the sites of SH and NH(2) labeling in alpha-crystallin. The site of SH labeling has medium-low polarity (dielectric constant, epsilon = 4.9 +/- 0.9) is protic, and does not contain proximal aromatic residues (according to the obtained refractive index, n = 1.41 +/- 0.14). The site of NH(2) labeling is also of medium-low polarity. The novel label due to its two-wavelength ratiometric response and high sensitivity to the type of labeling may offer new possibilities in the studies of structure, dynamics, and interactions of proteins by probing their SH- and NH(2)-labeling sites.