Chat and instant messaging : the risks of secondary orality

The synchronous nature of chat and instant messaging (IM) make them unique among computer-enabled communications technologies in that their real-time exchange of data allows for rich media experiences, even though users can only use text symbols to trade messages. Chat and IM are also important in that they enable secondary orality, or the merger of the most beneficial aspects of orally-based cultures with the well-documented benefits of print and text. Where print in the modem day has fostered contemplative behavior and inward thought among human beings, chat and IM breathe vitality into print and, in a sense, allow print to be spoken. Chat and IM have provided well-documented benefits for business, academia and everyday human socialization. However, when the tools are used beyond these narrow contexts they not only lose their effectiveness; they also pose credible threats to society. Because chat and IM provide anonymity to their participants, the virtual communities they support are typically loosely governed, driven by stereotype, and replete with social deviance. Further, the more attractive online environments become, the less time and energy people will invest in the physical world, thereby threatening that the habitats of humans will ultimately wither and decay. Finally, as humans become less able to extricate themselves from their computer-enabled habitats, they will increasingly rely on the computer as a social prosthetic--if not evolve to the point where human beings and computers become indistinguishable

Social Niche Construction in Brown-headed Cowbirds (Molothrus ater)

Thesis (Ph.D.) - Indiana University, Psychology, 2015Variation in reproductive behavior is essential to selection. Despite this, researchers know very little about the social factors shaping the development of such variation. Social niche construction reflects the ability of an individual to shape its social environment. A social niche reflects an individuals place within the larger social network of the group. Some niches reflect high levels of connectedness with others, whereas other niches reflect more selective connections. The early niche will shape the quality and frequency of social interactions, and may have a cascading influence onto later reproductive performance. In this dissertation I explored the sex differences in social niche construction within Brown-headed Cowbirds (Molothrus ater). Male and female cowbirds face divergent challenges when navigating the social environment. In this dissertation I investigated the different niches occupied by males and females over development, and how different niches predict later reproductive behavior. Female cowbirds construct predictable niches, whereas males construct more plastic niches. During the fusion of two novel flocks females maintain stronger connections with familiar females in contrast to males. The ability to form reliable networks with familiar conspecifics may influence the predictability of individual behavior across contexts. Across changes in group size and composition both adult and juvenile females maintain correlated patterns of both social approach and affiliative head-down displays, whereas males did not. Such variation is able to predict a female's reproductive behavior across long timescales. More frequent and closer interactions during the fall predict courtship behavior and pair bonds in juvenile females, and egg production in adult females. Such results suggest that the early niches and individual constructs may have evolutionary consequences by shaping the development of functionally relevant courtship and reproductive abilities

Effective Hamiltonian for Ga_{1-x}Mn_xAs in the Dilute Limit

We derive an effective Hamiltonian for ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ in the dilute limit, where ${\rm Ga}_{1-x}{\rm Mn}_x {\rm As}$ can be described in terms of spin $F=3/2$ polarons hopping between the {\rm Mn} sites and coupled to the local {\rm Mn} spins. We determine the parameters of our model from microscopic calculations. Our approach treats the large Coulomb interaction in a non-perturbative way, captures the effects of spin-orbit coupling and disorder, and is appropriate for other p-doped magnetic semiconductors. Our model applies to uncompensated {\rm Mn} concentrations up to $x \sim 0.03$.Comment: 4 pages, 4 figures, Version to appear in Phys. Rev. Let

Heme Dissociation from Myoglobin in the Presence of the Zwitterionic Detergent N,N-Dimethyl-N-Dodecylglycine Betaine: Effects of Ionic Liquids

We have investigated myoglobin protein denaturation using the zwitterionic detergent Empigen BB (EBB, N,N-Dimethyl-N-dodecylglycine betaine). A combination of absorbance, fluorescence, and circular dichroism spectroscopic measurements elucidated the protein denaturation and heme dissociation from myoglobin. The results indicated that Empigen BB was not able to fully denature the myoglobin structure, but apparently can induce the dissociation of the heme group from the protein. This provides a way to estimate the heme binding free energy, ΔGdissociation. As ionic liquids (ILs) have been shown to perturb the myoglobin protein, we have investigated the effects of the ILs 1-butyl-3-methylimidazolium chloride (BMICl), 1-ethyl-3-methylimidazolium acetate (EMIAc), and 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF4) in aqueous solution on the ΔGdissociation values. Absorbance experiments show the ILs had minimal effect on ΔGdissociation values when compared to controls. Fluorescence and circular dichroism data confirm the ILs have no effect on heme dissociation, demonstrating that low concentrations ILs do not impact the heme dissociation from the protein and do not significantly denature myoglobin on their own or in combination with EBB. These results provide important data for future studies of the mechanism of IL-mediated protein stabilization/destabilization and biocompatibility studies

Field Theory for a Deuteron Quantum Liquid

Based on general symmetry principles we study an effective Lagrangian for a neutral system of condensed spin-1 deuteron nuclei and electrons, at greater-than-atomic but less-than-nuclear densities. We expect such matter to be present in thin layers within certain low-mass brown dwarfs. It may also be produced in future shock-wave-compression experiments as an effective fuel for laser induced nuclear fusion. We find a background solution of the effective theory describing a net spin zero condensate of deuterons with their spins aligned and anti-aligned in a certain spontaneously emerged preferred direction. The spectrum of low energy collective excitations contains two spin waves with linear dispersions -- like in antiferromagnets -- as well as gapped longitudinal and transverse modes related to the Meissner effect -- like in superconductors. We show that counting of the Nambu-Goldstone modes of spontaneously broken internal and space-time symmetries obeys, in a nontrivial way, the rules of the Goldstone theorem for Lorentz non-invariant systems. We discuss thermodynamic properties of the condensate, and its potential manifestation in the low-mass brown dwarfs.Comment: 19 LaTeX pages; v2: 2 refs added, JHEP versio

In the Company of Cowbirds, Molothrus ater ater: Robust Patterns of Sociability Predict Reproductive Performance

Many species exhibit behavioral tendencies that are stable over time and across contexts. Robust variation in sociability, or the propensity to approach others, is widespread across the vertebrates. Nonetheless, the influence of sociability on reproductive performance is largely unknown. In this study, we explore the relationship between sociability and reproductive behavior in flocks of Brown-headed Cowbirds (Molothrus ater ater). In spring 2011, we separated birds into three large aviaries based on the number of approaches they initiated and received during fall 2010. Females were separated into high, intermediate, and low sociable flocks, while male sociability was spread evenly across the three flocks. Here we report for the first time that different patterns of social approach tendencies in the fall predicted reproductive behavior in the spring. The high sociable flocks contained more laying females who produced more eggs in contrast to the other flocks. Male courtship behavior was comparable across the three flocks. These findings suggest that robust variation in sociability is an important factor in reproductive performance

Effects of Ionic Liquid Alkyl Chain Length on Denaturation of Myoglobin by Anionic, Cationic, and Zwitterionic Detergents

The unique electrochemical properties of ionic liquids (ILs) have motivated their use as solvents for organic synthesis and green energy applications. More recently, their potential in pharmaceutical chemistry has prompted investigation into their effects on biomolecules. There is evidence that some ILs can destabilize proteins via a detergent-like manner; however, the mechanism still remains unknown. Our hypothesis is that if ILs are denaturing proteins via a detergent-like mechanism, detergent-mediated protein unfolding should be enhanced in the presence of ILs. The properties of myoglobin was examined in the presence of a zwitterionic (N,N-dimethyl-N-dodecylglycine betaine (Empigen BB®, EBB)), cationic (tetradecyltrimethylammonium bromide (TTAB)), and anionic (sodium dodecyl sulfate (SDS)) detergent as well as ILs based on alkylated imidazolium chlorides. Protein structure was measured through a combination of absorbance, fluorescence, and circular dichroism (CD) spectroscopy: absorbance and CD were used to monitor heme complexation to myoglobin, and tryptophan fluorescence quenching was used as an indicator for heme dissociation. Notably, the detergents tested did not fully denature the protein but instead resulted in loss of the heme group. At low IL concentrations, heme dissociation remained a traditional, cooperative process; at high concentrations, ILs with increased detergent-like character exhibited a more complex pattern, which is most likely attributable to micellization of the ionic liquids or direct denaturation or heme dissociation induced by the ILs. These trends were consistent across all species of detergents. 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence was further used to characterize micelle formation in aqueous solutions containing detergent and ionic liquid. The dissociation thermodynamics show that EBB- and TTAB-induced dissociation of heme is not significantly impacted by room temperature ionic liquids (RTILs), whereas SDS-induced dissociation is more dramatically impacted by all RTILs examined. Together, these results indicate a complex interaction of detergents, likely based on headgroup charge, and the active component of RTILs to influence heme dissociation and potentially protein denaturation