832 research outputs found

    Historical Traditions and Critical Perspectives: An Exploration of the Textual and Pedagogical Choices of Four Language Arts Teachers in an Urban, Diverse Secondary School

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    Even as current critical research in the teaching of English calls for a widening of traditional secondary texts and curricula choices, the presence of certain district, local, and state policies continue to permeate classrooms in extensive and oppressive ways that have limited the literature, the instructional strategies, and the autonomy that teachers bring into educational spaces. This qualitative study examines the pedagogical choices of four secondary language arts teachers within the framework of both historical and critical perspectives on the teaching of literature and within the realities of a high-stakes, evaluative teaching environment. Utilizing participatory action research (PAR) and collaborative inquiry, this community-based research at a highly diverse, urban high school in the southwest examines the text selection of four practicing language arts teachers. It analyzes whether the pedagogical choices of these teachers align with the holistic goals of critical literacy or return to more historically traditional forms of literature instruction. Ultimately, this study seeks to add to scholarship within research and theory in the teaching of English by exploring how current secondary teachers choose and approach a variety of texts within a larger trajectory of shifting frameworks and methods for secondary literature instruction

    Vaccines to prevent severe acute respiratory syndrome coronavirus-induced disease

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    An important effort has been performed after the emergence of severe acute respiratory syndrome (SARS) epidemic in 2003 to diagnose and prevent virus spreading. Several types of vaccines have been developed including inactivated viruses, subunit vaccines, virus-like particles (VLPs), DNA vaccines, heterologous expression systems, and vaccines derived from SARS-CoV genome by reverse genetics. This review describes several aspects essential to develop SARS-CoV vaccines, such as the correlates of protection, virus serotypes, vaccination side effects, and bio-safeguards that can be engineered into recombinant vaccine approaches based on the SARS-CoV genome. The production of effective and safe vaccines to prevent SARS has led to the development of promising vaccine candidates, in contrast to the design of vaccines for other coronaviruses, that in general has been less successful. After preclinical trials in animal models, efficacy and safety evaluation of the most promising vaccine candidates described has to be performed in humans

    An improved experimental test set-up to study the performance of granular columns

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    This paper describes an innovative design of a newly developed large test setup for testing the performance of footings supported on soft clay reinforced with granular columns. This advanced testing method is used to examine the settlement of footings supported on granular columns. Two important features of the equipment are (a) the axial loading system which allows samples to be consolidated under Ko condition while the load is applied onto a small foundation area of the sample, and (b) a relatively large sample size of 300-mm diameter and 400-mm high. The system is also equipped with pressure cells located beneath the footing and top cap to measure the pressure distribution with respect to foundation displacement and a lateral strain gage to monitor boundary effects. This paper reports on some of the early findings from the preliminary tests carried out using this equipment. Samples for testing were prepared by consolidating kaolin slurry in a large one-dimensional consolidation chamber. The granular columns were installed using the replacement method by compacting crushed basalt (uniformly graded with 90 % between 1.5–2-mm particle sizes) into a preformed hole. The preliminary tests have yielded promising results, validating the functionality of the equipment and support the prospect of increasing the knowledge with respect to settlement response and design of a footing supported on granular columns

    Teaching across disciplines: a case study of a project-based short course to teach holistic coastal adaptation design

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    Climate change has led to the need for innovation in resilient infrastructure and the social policies which will support those. This requires greater interdisciplinary interactions and knowledge building among emerging professionals. This paper presents a case study of a pilot short course intended to immerse graduate students in the design of resilient infrastructure using place-based and interdisciplinary active team learning. This course helps graduate students bridge the gap between research and practice on the social science and engineering of resilient infrastructure for coastal adaptation. The intellectual framework for the course (the Adaptive Gradients Framework) provides a holistic evaluation of adaptation design proposals and was used to recognize the complexity of social, ecological and engineering aspects and varied social benefits. The course provides a model to move outside rigid boundaries of institutions and disciplines to begin to build, in both students and instructors, the ability to work more effectively on complex social-ecological-engineering problems. Finally, this paper presents a summary of lessons learned from this pilot short course

    An Assessment of the Model of Concentration Addition for Predicting the Estrogenic Activity of Chemical Mixtures in Wastewater Treatment Works Effluents

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    The effects of simple mixtures of chemicals, with similar mechanisms of action, can be predicted using the concentration addition model (CA). The ability of this model to predict the estrogenic effects of more complex mixtures such as effluent discharges, however, has yet to be established. Effluents from 43 U.K. wastewater treatment works were analyzed for the presence of the principal estrogenic chemical contaminants, estradiol, estrone, ethinylestradiol, and nonylphenol. The measured concentrations were used to predict the estrogenic activity of each effluent, employing the model of CA, based on the relative potencies of the individual chemicals in an in vitro recombinant yeast estrogen screen (rYES) and a short-term (14-day) in vivo rainbow trout vitellogenin induction assay. Based on the measured concentrations of the four chemicals in the effluents and their relative potencies in each assay, the calculated in vitro and in vivo responses compared well and ranged between 3.5 and 87 ng/L of estradiol equivalents (E2 EQ) for the different effluents. In the rYES, however, the measured E2 EQ concentrations in the effluents ranged between 0.65 and 43 ng E2 EQ/L, and they varied against those predicted by the CA model. Deviations in the estimation of the estrogenic potency of the effluents by the CA model, compared with the measured responses in the rYES, are likely to have resulted from inaccuracies associated with the measurement of the chemicals in the extracts derived from the complex effluents. Such deviations could also result as a consequence of interactions between chemicals present in the extracts that disrupted the activation of the estrogen response elements in the rYES. E2 EQ concentrations derived from the vitellogenic response in fathead minnows exposed to a series of effluent dilutions were highly comparable with the E2 EQ concentrations derived from assessments of the estrogenic potency of these dilutions in the rYES. Together these data support the use of bioassays for determining the estrogenic potency of WwTW effluents, and they highlight the associated problems for modeling approaches that are reliant on measured concentrations of estrogenic chemicals

    Process simulation and techno-economic assessment for direct production of advanced bioethanol using a genetically modified Synechocystis sp.

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    ABSTRACT: A techno-economic assessment for the direct production of ethanol using a genetically-modified microalgae has been studied. It was considered two main scenarios for process modelling: i) bioenergy-driven microalgae plant, i.e., focused on the production of fuel-grade ethanol and biogas for CHP and, ii) biorefinery-driven microalgae plant, focused on the recovery of added-value bioproducts (zeaxanthin and phycocyanin) along with ethanol and CHP production. These main scenarios and several variants were modelled and optimized for a small-scale demo plant of 1000 Lethanol/day and extrapolated for larger production capacities. Results showed that despite the innovative approach of direct production of ethanol by microalgae, the bioenergy-driven scenario is non-feasible under the studied conditions. Conversely, ethanol production becomes economically feasible as co-product in the biorefinery-driven scenario although having payback periods>10 years. Furthermore, if only bio-based products are produced the NPV and the payback are even more positive, 104.8 M€ and ca. 5 years, respectively.info:eu-repo/semantics/publishedVersio

    A new isotropic cell for studying the thermo-mechanical behavior of unsaturated expansive clays

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    This paper presents a new suction-temperature controlled isotropic cell that can be used to study the thermo-mechanical behavior of unsaturated expansive clays. The vapor equilibrium technique is used to control the soil suction; the temperature of the cell is controlled using a thermostat bath. The isotropic pressure is applied using a volume/pressure controller that is also used to monitor the volume change of soil specimen. Preliminary experimental results showed good performance of the cell

    Virus–Host Interactions Between Nonsecretors and Human Norovirus

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    BACKGROUND & AIMS: Human norovirus infection is the leading cause of acute gastroenteritis. Genetic polymorphisms, mediated by the FUT2 gene (secretor enzyme), define strain susceptibility. Secretors express a diverse set of fucosylated histoblood group antigen carbohydrates (HBGA) on mucosal cells; nonsecretors (FUT2-/-) express a limited array of HBGAs. Thus, nonsecretors have less diverse norovirus strain infections, including resistance to the epidemiologically dominant GII.4 strains. Because future human norovirus vaccines will comprise GII.4 antigen and because secretor phenotype impacts GII.4 infection and immunity, nonsecretors may mimic young children immunologically in response to GII.4 vaccination, providing a needed model to study crossprotection in the context of limited pre-exposure. METHODS: By using specimens collected from the first characterized nonsecretor cohort naturally infected with GII.2 human norovirus, we evaluated the breadth of serologic immunity by surrogate neutralization assays, and cellular activation and cytokine production by flow cytometry. RESULTS: GII.2 infection resulted in broad antibody and cellular immunity activation that persisted for at least 30 days for T cells, monocytes, and dendritic cells, and for 180 days for blocking antibody. Multiple cellular lineages expressing interferon-g and tumor necrosis factor-a dominated the response. Both T-cell and B-cell responses were cross-reactive with other GII strains, but not GI strains. To promote entry mechanisms, inclusion of bile acids was essential for GII.2 binding to nonsecretor HBGAs. CONCLUSIONS: These data support development of withingenogroup, cross-reactive antibody and T-cell immunity, key outcomes that may provide the foundation for eliciting broad immune responses after GII.4 vaccination in individuals with limited GII.4 immunity, including young children
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