To transduce a zebra finch: interrogating behavioral mechanisms in a model system for speech.

The ability to alter neuronal gene expression, either to affect levels of endogenous molecules or to express exogenous ones, is a powerful tool for linking brain and behavior. Scientists continue to finesse genetic manipulation in mice. Yet mice do not exhibit every behavior of interest. For example, Mus musculus do not readily imitate sounds, a trait known as vocal learning and a feature of speech. In contrast, thousands of bird species exhibit this ability. The circuits and underlying molecular mechanisms appear similar between disparate avian orders and are shared with humans. An advantage of studying vocal learning birds is that the neurons dedicated to this trait are nested within the surrounding brain regions, providing anatomical targets for relating brain and behavior. In songbirds, these nuclei are known as the song control system. Molecular function can be interrogated in non-traditional model organisms by exploiting the ability of viruses to insert genetic material into neurons to drive expression of experimenter-defined genes. To date, the use of viruses in the song control system is limited. Here, we review prior successes and test additional viruses for their capacity to transduce basal ganglia song control neurons. These findings provide a roadmap for troubleshooting the use of viruses in animal champions of fascinating behaviors-nowhere better featured than at the 12th International Congress

The Impact of Transit-Oriented Development on Social Capital

This paper focuses on the ability of Transit Oriented Development (TOD) to improve social capital and interactions within a community. The expectation is that TOD has a positive impact on the lifestyle and activities of individuals who reside, work, and frequent these locations, and that this can include increases in social capital. Using data from a survey of transit station locations in New Jersey, the authors examine how proximity to the station and various built environment variables are associated with different measures of social capital, derived from responses to survey questions. These questions inquire about respondents’ perceptions of their neighborhood as a place to live, sense of community, knowing their neighbors, trust, and whether their community is a good place to raise a child. The authors also include a question on volunteering in the community. These questions reflect various domains of social capital as established in the literature. Results generally do not support the hypothesis that social capital is associated with transit station proximity and TOD. Features of the built environment, proxied by population and employment density, are also not associated with increased social capital, and in some cases have a negative association. While there are some limited positive associations with some of the social capital variables, one of the strongest indicators is living in a detached family home

Enterohemorrhagic Escherichia coli colonization of human colonic epithelium in vitro and ex vivo

Enterohemorrhagic E. coli (EHEC) are important foodborne pathogens causing gastroenteritis and more severe complications such as hemorrhagic colitis and hemolytic uremic syndrome. Pathology is most pronounced in the colon, but to date there is no direct clinical evidence showing EHEC binding to colonic epithelium in patients. In this study, we investigated EHEC adherence to the human colon by using in vitro organ culture (IVOC) of colonic biopsies and polarized T84 colon carcinoma cells. We showed for the first time that EHEC colonized human colonic biopsies by forming typical attaching/effacing (A/E) lesions which were dependent on EHEC type III secretion (T3S) and binding of the outer membrane protein intimin to the Translocated intimin receptor (Tir). A/E lesion formation was dependent on oxygen levels and suppressed under oxygen-rich culture conditions routinely used for IVOC. In contrast, EHEC adherence to polarized T84 cells occurred independently of T3S and intimin and did not involve Tir translocation into the host cell membrane. Neither colonization of biopsies nor T84 cells was significantly affected by expression of Shiga toxins. Our study suggests that EHEC colonize and form stable A/E lesions on the human colon which is likely to contribute to intestinal pathology during infection. Furthermore, care needs to be taken when using cell culture models as they might not reflect the in vivo situation

Emergence of topological electronic phases in elemental lithium under pressure

Lithium, a prototypical simple metal under ambient conditions, has a surprisingly rich phase diagram under pressure, taking up several structures with reduced symmetry, low coordination numbers, and even semiconducting character with increasing density. Using first-principles calculations, we demonstrate that some predicted high-pressure phases of elemental Li also host topological electronic structures. Beginning at 80 GPa and coincident with a transition to the Pbca phase, we find Li to be a Dirac nodal line semimetal. We further calculate that Li retains linearly-dispersive energy bands in subsequent predicted higher pressure phases, and that it exhibits a Lifshitz transition between two Cmca phases at 220 GPa. The Fd-3m phase at 500 GPa forms buckled honeycomb layers that give rise to a Dirac crossing 1 eV below the Fermi energy. The well-isolated topological nodes near the Fermi level in these phases result from increasing p-orbital character with density at the Fermi level, itself a consequence of rising 1s core wavefunction overlap, and a preference for nonsymmorphic symmetries in the crystal structures favored at these pressures. Our results provide evidence that under pressure, bulk 3D materials with light elements, or even pure elemental systems, can undergo topological phase transitions hosting nontrivial topological properties near the Fermi level with measurable consequences; and that, through pressure, we can access these novel phases in elemental lithium.Comment: 5 pages, 5 figures, accepted for publicatio

Kids' Share 2010: Report on Federal Expenditures on Children

Examines 1960-2009 trends in federal spending and tax expenditures on children, including food stamps, tax credits, and Head Start. Analyzes the effects of American Recovery and Reinvestment Act funding, projected funding through 2020, and implications

State of Alaska Election Security Project Phase 2 Report

A laska’s election system is among the most secure in the country, and it has a number of safeguards other states are now adopting. But the technology Alaska uses to record and count votes could be improved— and the state’s huge size, limited road system, and scattered communities also create special challenges for insuring the integrity of the vote. In this second phase of an ongoing study of Alaska’s election security, we recommend ways of strengthening the system—not only the technology but also the election procedures. The lieutenant governor and the Division of Elections asked the University of Alaska Anchorage to do this evaluation, which began in September 2007.Lieutenant Governor Sean Parnell. State of Alaska Division of Elections.List of Appendices / Glossary / Study Team / Acknowledgments / Introduction / Summary of Recommendations / Part 1 Defense in Depth / Part 2 Fortification of Systems / Part 3 Confidence in Outcomes / Conclusions / Proposed Statement of Work for Phase 3: Implementation / Reference