Search

Culturally relevant pedagogy (CRP) described in Ladson-Billings' framework has three conceptions: "conceptions of self and others," "conceptions of knowledge," and "conceptions of social relations." Instructors can support students with positive learning experiences when they are cognizant of all three conceptions. In 13 interviews of physics instructors about CRP, we found many instructors shared only two productive conceptions: conceptions of self and others and conceptions of social relations. However, we found two instructors who effectively described all three conceptions. Their conceptions of knowledge focused on physics knowledge as constructed, reconstructed, and in some aspects containing subjectivity. They both articulated a critical approach to examining the historical and contextual factors that influence physics learning today. Our findings indicate that instructors' beliefs about the nature of science can be entangled with their own enactment of CRP and we show how a sophisticated epistemology can be one route to more culturally relevant instruction.

To promote a STEM career pipeline, a mentor outreach program was created within a K-12 charter school network, with a pilot year focusing on eighth and ninth-grade students. Utilizing a small cohort of volunteers from a nearby community college as student mentors and one faculty member, 12 visits were conducted throughout the school year. The mentors led science activities, made connections to their collegiate coursework in science, and worked to establish mentor relationships with students in order to motivate them to pursue science upon high school completion. As a result, survey data from the beginning compared to the end of the academic year showed increases in favorable perception of science by as much as 25%. This is most pronounced in young female students of color and by students whose parents have a high school education or lower.

There is urgent need for new drug regimens that more rapidly cure tuberculosis (TB). Existing TB drugs and regimens vary in treatment-shortening activity, but the molecular basis of these differences is unclear, and no existing assay directly quantifies the ability of a drug or regimen to shorten treatment. Here, we show that drugs historically classified as sterilizing and non-sterilizing have distinct impacts on a fundamental aspect of Mycobacterium tuberculosis physiology: ribosomal RNA (rRNA) synthesis. In culture, in mice, and in human studies, measurement of precursor rRNA reveals that sterilizing drugs and highly effective drug regimens profoundly suppress M. tuberculosis rRNA synthesis, whereas non-sterilizing drugs and weaker regimens do not. The rRNA synthesis ratio provides a readout of drug effect that is orthogonal to traditional measures of bacterial burden. We propose that this metric of drug activity may accelerate the development of shorter TB regimens.

Remote access technology in STEM education fills dual roles as an educational tool to deliver science education (Educational Technology) and as a means to teach about technology itself (Technology Education). A five-lesson sequence was introduced to 11 and 12-year-old students at an urban school. The lesson sequences were inquiry-based, hands-on, and utilized active learning pedagogies, which have been implemented in STEM classrooms worldwide. Each lesson employed a scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) accessed remotely. Students were assessed using multiple-choice questions to ascertain (1) technology education learning gains: did students gain an understanding of how electron microscopes work? and (2) educational technology learning gains: did students gain a better understanding of lesson content through use of the electron microscope? Likert-item surveys were developed, distributed, and analyzed to established how remote access technology affected student attitudes toward science, college, and technology. Participating students had a positive increase in attitudes toward scientific technology by engaging in the lesson sequences, reported positive attitudes toward remote access experiences, and exhibited learning gains in the science behind the SEM technology they accessed remotely. These findings suggest that remote experiences are a strong form of technology education, but also that future research could explore ways to strengthen remote access as an educational technology (a tool to deliver lesson content), such as one-on-one engagement. This study promotes future research into inquiry-based, hands-on, integrated lessons approach that utilize educational technology learning through remote instruments as a pedagogy to increase students' engagement with and learning of the "T" in STEM.

Lung myeloid cells are important in pulmonary immune homeostasis and in the pathogenesis of chronic obstructive pulmonary disease (COPD). Multiparameter immunophenotypic characterization of these cells is challenging because of their autofluorescence and diversity. We evaluated the immunophenotypic landscape of airway myeloid cells in COPD using time of flight mass cytometry. Cells from BAL, which were obtained from never-smokers (n = 8) and smokers with (n = 20) and without (n = 4) spirometric COPD, were examined using a 44-parameter time of flight mass cytometry panel. Unsupervised cluster analysis was used to identify cellular subtypes that were confirmed by manual gating. We identified major populations of CD68+ and CD68- cells with 22 distinct phenotypic clusters, of which 18 were myeloid cells. We found a higher abundance of putative recruited myeloid cells (CD68+ classical monocytes) in BAL from patients with COPD. CD68+ classical monocyte population had distinct responses to smoking and COPD that were potentially related to their recruitment from the interstitium and vasculature. We demonstrate that BAL cells from smokers and subjects with COPD have lower AXL expression. Also, among subjects with COPD, we report significant differences in the abundance of PDL1high and PDL2high clusters and in the expression of PDL1 and PDL2 across several macrophage subtypes suggesting modulation of inflammatory responses. In addition, several phenotypic differences in BAL cells from subjects with history of COPD exacerbation were identified that could inform potential disease mechanisms. Overall, we report several changes to the immunophenotypic landscape that occur with smoking, COPD, and past exacerbations that are consistent with decreased regulation and increased activation of inflammatory pathways.

A multidisciplinary science experiment was performed in K-12 classrooms focusing on the interconnection between technology with geology and chemistry. The engagement and passion for science of over eight hundred students across twenty-one classrooms, utilizing a combination of hands-on activities using relationships between Earth and space rock studies, followed by a remote access session wherein students remotely employed the use of a scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) to validate their findings was investigated. Participants represent predominantly low-income minority communities, with little exposure to the themes and equipment used, despite being freely available resources. Students indicated greatly increased interest in scientific practices and careers, as well as a better grasp of the content as a result of the lab and remote access coupling format.

The manufacture of metal alloys is ubiquitous, yet infrequently discussed in high school coursework as concepts related to them are often too complex or abstract for beginning science students. However, earlier introduction to metallurgy in classroom settings could promote interest in practical applications of chemistry, physics, and geology due to the demonstrable significance of materials in daily use. Elemental metals with low melting points such as bismuth, zinc and tin are melted down, mixed at various percent compositions, and allowed to solidify. The solidified composites are then broken open to examine resulting internal structures. Changes in physical properties of new compositions are observed, analyzed, and discussed. Experimental results are the basis for a multi-tiered laboratory experiment for high school chemistry or geoscience courses. From introductory, inquiry-based techniques in chemistry to more advanced concepts in petrology, each lab can be tuned to cover a wide spectrum of multi-dimensional science applications.

BackgroundIdentifying biomarkers for cells harboring replication-competent HIV is a major research priority. Recently, there have been mixed reports addressing the possibility that CD32-expressing T cells are enriched for HIV. There is growing evidence that CD32 expression increases with cellular activation that may be related to, but not necessarily specific for, infection with HIV. However, the relationship of CD32 expression to HIV-infection in subtypes of tissue-resident leukocytes is unclear.MethodsFirst, we used duplex chromogenic in situ hybridization to identify cells actively transcribing RNA for both CD32 and HIV on human gut tissues. Then we performed multiplexed immunofluorescence and in situ hybridization (mIFISH) on sections from the same tissues to determine the phenotype of individual cells co-expressing HIV-RNA and CD32-RNA.ResultsHIV-RNA+ cells were more abundant in tissues from viremic individuals than in those receiving suppressive anti-retroviral therapy (ART). However, staining by both methods indicated that a higher proportion of HIV-RNA+ cells co-expressed CD32-RNA in ART-suppressed individuals than in those with viremia. The majority of HIV-RNA+ cells were CD3+.ConclusionsOur data suggest that the transcription of CD32-RNA is correlated with HIV transcriptional activity in CD3+ cells found within human gut tissue. Whether or not up-regulation of CD32-RNA is a direct result of HIV transcription or more global T-cell activation remains unclear.

Persistent tissue reservoirs of HIV present a major barrier to cure. Defining subsets of infected cells in tissues is a major focus of HIV cure research. Herein, we describe a novel multiplexed in situ hybridization (ISH) (RNAscope) protocol to detect HIV-DNA (vDNA) and HIV-RNA (vRNA) in formalin-fixed paraffin-embedded (FFPE) human tissues in combination with immunofluorescence (IF) phenotyping of the infected cells. We show that multiplexed IF and ISH (mIFISH) is suitable for quantitative assessment of HIV vRNA and vDNA and that multiparameter IF phenotyping allows precise identification of the cellular source of the ISH signal. We also provide semi-quantitative data on the impact of various tissue fixatives on the detectability of vDNA and vRNA with RNAscope technology. Finally, we describe methods to quantitate the ISH signal on whole-slide digital images and validation of the quantitative ISH data with quantitative real-time PCR for vRNA. It is our hope that this approach will provide insight into the biology of HIV tissue reservoirs and to inform strategies aimed at curing HIV.

HIV-1-infected cells persist indefinitely despite the use of combination antiretroviral therapy (ART), and novel therapeutic strategies to target and purge residual infected cells in individuals on ART are urgently needed. Here, we demonstrate that CD4+ T cell-associated HIV-1 RNA is often highly enriched in cells expressing CD30, and that cells expressing this marker considerably contribute to the total pool of transcriptionally active CD4+ lymphocytes in individuals on suppressive ART. Using in situ RNA hybridization studies, we show co-localization of CD30 with HIV-1 transcriptional activity in gut-associated lymphoid tissues. We also demonstrate that ex vivo treatment with brentuximab vedotin, an antibody-drug conjugate (ADC) that targets CD30, significantly reduces the total amount of HIV-1 DNA in peripheral blood mononuclear cells obtained from infected, ART-suppressed individuals. Finally, we observed that an HIV-1-infected individual, who received repeated brentuximab vedotin infusions for lymphoma, had no detectable virus in peripheral blood mononuclear cells. Overall, CD30 may be a marker of residual, transcriptionally active HIV-1 infected cells in the setting of suppressive ART. Given that CD30 is only expressed on a small number of total mononuclear cells, it is a potential therapeutic target of persistent HIV-1 infection.

To characterize susceptibility to HIV infection, we phenotyped infected tonsillar T cells by single-cell mass cytometry and created comprehensive maps to identify which subsets of CD4+ T cells support HIV fusion and productive infection. By comparing HIV-fused and HIV-infected cells through dimensionality reduction, clustering, and statistical approaches to account for viral perturbations, we identified a subset of memory CD4+ T cells that support HIV entry but not viral gene expression. These cells express high levels of CD127, the IL-7 receptor, and are believed to be long-lived lymphocytes. In HIV-infected patients, CD127-expressing cells preferentially localize to extrafollicular lymphoid regions with limited viral replication. Thus, CyTOF-based phenotyping, combined with analytical approaches to distinguish between selective infection and receptor modulation by viruses, can be used as a discovery tool.

This work compares the effects of adding water vapor and CO2 as diluent to fuel for a diffusion flame at different ambient pressures. The approach of this research is to study numerically a methane diffusion flame with various amounts of water vapor and CO2 added to the fuel, and to compare the flame behaviors with various percentages of water vapor and CO2 content (0% to 65%). This work uses a coflow burner in the PeleLM numerical framework for simulating the flame and computing the combustion behavior. The flame was simulated with pressures of 1.0, 1.4, 5.7, and 11.1 atm. The results extracted and analyzed include temperature profiles at fixed heights and various species mole fractions compared with their values at an equilibrium state condition. The results show that most of the diluent impact does not involve changes in flame chemistry but primarily changes to heat release and heat capacity in the flames. The results also show that the diluent amount has a much larger impact on flame behavior than do changes in pressure. [ABSTRACT FROM AUTHOR]

This response to Tom Bryce's paper aims to supplement some of the critical points made regarding the imbalance between content, process, and context in today's science education curriculum in higher learning institutions. Discussion and examples of how the present student-mentor relationship fosters tribe mentality are also included. However a caution is also suggested against the treatment of science as a purely subjective process, overrun by self-interested and exclusive parties.