Circuit breakers: back to the basics

Stock market

Voices From the Street: A Survey of Homeless Youth by Their Peers

Summarizes interviews of homeless or formerly homeless youth by their peers about how they became homeless, their lives on the street, interactions with police, education, aspirations, mental health, support networks, services, and policy suggestions

Assortative Mating By Diet In A Phenotypically Unimodal But Ecologically Variable Population Of Stickleback

Speciation with gene flow may be driven by a combination of positive assortative mating and disruptive selection, particularly if selection and assortative mating act on the same trait, eliminating recombination between ecotype and mating type. Phenotypically unimodal populations of threespine stickleback (Gasterosteus aculeatus) are commonly subject to disruptive selection due to competition for alternate prey. Here we present evidence that stickleback also exhibit assortative mating by diet. Among-individual diet variation leads to variation in stable isotopes, which reflect prey use. We find a significant correlation between the isotopes of males and eggs within their nests. Because egg isotopes are derived from females, this correlation reflects assortative mating between males and females by diet. In concert with disruptive selection, this assortative mating should facilitate divergence. However, the stickleback population remains phenotypically unimodal, highlighting the fact that assortative mating and disruptive selection do not guarantee evolutionary divergence and speciation.Integrative Biolog

An evolutionary economic perspective on technical change and adjustment in cane harvesting systems in the Australian sugar industry

Australian sugar-producing regions have differed in terms of the extent and rate of incorporation of new technology into harvesting systems. The Mackay sugar industry has lagged behind most other sugar-producing regions in this regard. The reasons for this are addressed by invoking an evolutionary economics perspective. The development of harvesting systems, and the role of technology in shaping them, is mapped and interpreted using the concept of path dependency. Key events in the evolution of harvesting systems are identified, which show how the past has shaped the regional development of harvesting systems. From an evolutionary economics perspective, the outcomes observed are the end result of a specific history.Crop Production/Industries,

Increased mRNA Expression for the α\u3csub\u3e1\u3c/sub\u3e Subunit of the GABA\u3csub\u3eA\u3c/sub\u3e Receptor Following Nitrous Oxide Exposure in Mice

The mechanisms by which nitrous oxide (N2O) produces physical dependence and withdrawal seizures are not well understood, but both N2O and ethanol exert some of their effects via the GABAA receptor and several lines of evidence indicate that withdrawal from N2O and ethanol may be produced through similar mechanisms. Expression levels of mRNA transcripts encoding several GABAA receptor subunits change with chronic ethanol exposure and, therefore, we hypothesized that N2O exposure would produce changes in mRNA expression for the α1 subunit. Male, Swiss–Webster mice, 10–12 weeks of age, were exposed for 48 h to either room air or a 75%:25% N2O:O2 environment. Brains were sectioned and mRNA for the a subunit was detected by in situ hybridization using an 35S-labelled cRNA probe. N2O exposure produced a significant increase in expression levels of the α1 subunit mRNA in the cingulate cortex, the CA1/2 region of the hippocampus, the dentate gyrus, the subiculum, the medial septum, and the ventral tegmental area. These results lend support to the hypothesis that N2O effects are produced, at least in part, through the GABAA receptor and that N2O produces these effects through actions in the cingulate cortex, hippocampus, ventral tegmental area and medial septum. These results are also further evidence that ethanol and N2O produce dependence and withdrawal through common mechanisms

Fostering Student Agency to Build a Whole Child, Whole School, Whole Community Approach

In this practitioner perspective, we explore the concept of student agency through the implementation of a student government association in a laboratory middle school. Interviews with a social studies teacher and her students offer perspectives of the impact of student voice and choice for student experiences. We describe three major lessons learned through this implementation process: students learn to have healthy conflict and cooperative skills; students learn the appropriate processes to enact change in a democratic society; and students learn to conduct service for their peers, school, and community