Abaixando expectativas: Uma proposta modesta para uma pesquisa das política de ensino baseadas nas práticas

This proposal addresses the assumptions underlying the “Science Wars” about the purpose of educational research. The author proposes a more modest “Lake Woebegon” approach to school reform that supports long-term professional education, a shift away from “Best Practices” to “Pretty Good Practices,” low fidelity implementation of interventions, and the importance of local context. Action research is presented as one possible qualitative approach for conducting “practice-based research.”Esta propuesta trata de los supuestos que subyacen a las "guerras científicas" para determinar el propósito de la investigación educativa. El autor propone un enfoque más modesto  basado en el modelo del "Lago Woebegon" para reformas escolares apoyando la educación profesional a largo plazo, y alejándose del modelo de las "mejores prácticas" y acercándose a uno que de "practicas bastante buenas” , intervenciones de baja fidelidad, que den importancia al contexto local. La investigación-acción se presenta como un posible enfoque cualitativo para una investigación de las políticas  de enseñanza basada en las practicas.Esta proposta aborda os pressupostos subjacentes às "guerras da ciência" para determinar a finalidade da pesquisa educacional. O autor propõe uma abordagem mais modesta com base no modelo de "Lago Woebegon" de reformas escolares para apoiar a formação profissional de longo prazo, e longe do modelo de "melhores práticas" e aproximando-se a um modelo das " práticas bastante boas" usando intervenções de “baixa fidelidade” dando importância para o contexto local. A pesquisa-ação é apresentada como uma possível abordagem qualitativo das pesquisa de política de ensino baseadas nas práticas

Kids Make Sense... And They Vote: The Importance of Child Study in Learning to Teach Responsively

A lecture that discusses the developmental-interaction perspective and practice that has become the hallmark of Bank Street. Erickson builds upon the relations of mutual influence among students, teachers, and learning environments, and taking account of the relations between local practice within the small-scale here and now interactional ecosystems of immediate learning environments and the workings of culture, language, and society across more distal connections in social space and time

Strategic Water

After the final phase of drawdown of U.S. troops in Iraq, it is important to do what we can to help maintain a level of stability and to look ahead to emerging security threats. Strategic Water: Iraq and Security Planning in the Euphrates-Tigris Basin by Frederick Lorenz and Edward J. Erickson makes an important contribution to this effort by taking a close look at a serious problem that is often neglected—the decline in freshwater availability and its impact on regional securit

The role of TcdB and TccC subunits in secretion of the photorhabdus Tcd toxin complex

The Toxin Complex (TC) is a large multi-subunit toxin encoded by a range of bacterial pathogens. The best-characterized examples are from the insect pathogens Photorhabdus, Xenorhabdus and Yersinia. They consist of three large protein subunits, designated A, B and C that assemble in a 5:1:1 stoichiometry. Oral toxicity to a range of insects means that some have the potential to be developed as pest control technology. The three subunit proteins do not encode any recognisable export sequences and as such little progress has been made in understanding their secretion. We have developed heterologous TC production and secretion models in E. coli and used them to ascribe functions to different domains of the crucial B+C sub-complex. We have determined that the B and C subunits use a secretion mechanism that is either encoded by the proteins themselves or employ an as yet undefined system common to laboratory strains of E. coli. We demonstrate that both the N-terminal domains of the B and C subunits are required for secretion of the whole complex. We propose a model whereby the N-terminus of the C-subunit toxin exports the B+C sub-complex across the inner membrane while that of the B-subunit allows passage across the outer membrane. We also demonstrate that even in the absence of the B-subunit, that the C-subunit can also facilitate secretion of the larger A-subunit. The recognition of this novel export system is likely to be of importance to future protein secretion studies. Finally, the identification of homologues of B and C subunits in diverse bacterial pathogens, including Burkholderia and Pseudomonas, suggests that these toxins are likely to be important in a range of different hosts, including man

T Cell Responses to Human Endogenous Retroviruses in HIV-1 Infection

Human endogenous retroviruses (HERVs) are remnants of ancient infectious agents that have integrated into the human genome. Under normal circumstances, HERVs are functionally defective or controlled by host factors. In HIV-1-infected individuals, intracellular defense mechanisms are compromised. We hypothesized that HIV-1 infection would remove or alter controls on HERV activity. Expression of HERV could potentially stimulate a T cell response to HERV antigens, and in regions of HIV-1/HERV similarity, these T cells could be cross-reactive. We determined that the levels of HERV production in HIV-1-positive individuals exceed those of HIV-1-negative controls. To investigate the impact of HERV activity on specific immunity, we examined T cell responses to HERV peptides in 29 HIV-1-positive and 13 HIV-1-negative study participants. We report T cell responses to peptides derived from regions of HERV detected by ELISPOT analysis in the HIV-1-positive study participants. We show an inverse correlation between anti-HERV T cell responses and HIV-1 plasma viral load. In HIV-1-positive individuals, we demonstrate that HERV-specific T cells are capable of killing cells presenting their cognate peptide. These data indicate that HIV-1 infection leads to HERV expression and stimulation of a HERV-specific CD8+ T cell response. HERV-specific CD8+ T cells have characteristics consistent with an important role in the response to HIV-1 infection: a phenotype similar to that of T cells responding to an effectively controlled virus (cytomegalovirus), an inverse correlation with HIV-1 plasma viral load, and the ability to lyse cells presenting their target peptide. These characteristics suggest that elicitation of anti-HERV-specific immune responses is a novel approach to immunotherapeutic vaccination. As endogenous retroviral sequences are fixed in the human genome, they provide a stable target, and HERV-specific T cells could recognize a cell infected by any HIV-1 viral variant. HERV-specific immunity is an important new avenue for investigation in HIV-1 pathogenesis and vaccine design

Real-time imaging of density ducts between the plasmasphere and ionosphere

Ionization of the Earth's atmosphere by sunlight forms a complex, multilayered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and plasmasphere. The plasmasphere is believed to be embedded with cylindrical density structures (ducts) aligned along the Earth's magnetic field, but direct evidence for these remains scarce. Here we report the first direct wide-angle observation of an extensive array of field-aligned ducts bridging the upper ionosphere and inner plasmasphere, using a novel ground-based imaging technique. We establish their heights and motions by feature tracking and parallax analysis. The structures are strikingly organized, appearing as regularly spaced, alternating tubes of overdensities and underdensities strongly aligned with the Earth's magnetic field. These findings represent the first direct visual evidence for the existence of such structures

Role of CYP27A in cholesterol and bile acid metabolism

The CYP27A gene encodes a mitochondrial cytochrome P450 enzyme, sterol 27-hydroxylase, that is expressed in many different tissues and plays an important role in cholesterol and bile acid metabolism. In humans, CYP27A deficiency leads to cerebrotendinous xanthomatosis. To gain insight into the roles of CYP27A in the regulation of cholesterol and bile acid metabolism, cyp27A gene knockout heterozygous, homozygous, and wild-type littermate mice were studied. In contrast to homozygotes, heterozygotes had increased body weight and were mildly hypercholesterolemic, with increased numbers of lipoprotein particles in the low density lipoprotein size range. Cyp7A expression was not increased in heterozygotes but was in homozygotes, suggesting that parts of the homozygous phenotype are secondary to increased cyp7A expression and activity. Homozygotes exhibited pronounced hepatomegaly and dysregulation in hepatic cholesterol, bile acid, and fatty acid metabolism. Hepatic cholesterol synthesis and synthesis of bile acid intermediates were increased; however, side chain cleavage was impaired, leading to decreased bile salt concentrations in gallbladder bile. Expression of Na-taurocholate cotransporting polypeptide, the major sinusoidal bile salt transporter, was increased, and that of bile salt export pump, the major canalicular bile salt transporter, was decreased. Gender played a modifying role in the homozygous response to cyp27A deficiency, with females being gen

Farmers’ attitudes about farming and the environment: A survey of conventional and organic farmers

Farmers have been characterized as people whose ties to the land have given them a deep awareness of natural cycles, appreciation for natural beauty and sense of responsibility as stewards. At the same time, their relationship to the land has been characterized as more utilitarian than that of others who are less directly dependent on its bounty. This paper explores this tension by comparing the attitudes and beliefs of a group of conventional farmers to those of a group of organic farmers. It was found that while both groups reject the idea that a farmer’s role is to conquer nature, organic farmers were significantly more supportive of the notion that humans should live in harmony with nature. Organic farmers also reported a greater awareness of and appreciation for nature in their relationship with the land. Both groups view independence as a main benefit of farming and a lack of financial reward as its main drawback. Overall, conventional farmers report more stress in their lives although they also view themselves in a caretaker role for the land more than do the organic farmers. In contrast, organic farmers report more satisfaction with their lives, a greater concern for living ethically, and a stronger perception of community. Finally, both groups are willing to have their rights limited (organic farmers somewhat more so) but they do not trust the government to do so.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83671/1/Sullivan,_S.,_E._McCann,_R._De_Young_&_D._Erickson_(1996)._Farmers_attitudes_about_farming_and_the_environment,_JAEE,_9,_123-143.pd