882 research outputs found
Critically Assessing Forms of Resistance in Music Education
In their classrooms, music educators draw upon critical pedagogy (as described by Freire, Giroux, and hooks) for the express purpose of cultivating a climate for conscientização. Conscientização, according to Paulo Freire (2006), “refers to learning to perceive social, political, and economic contradictions and to take action against the oppressive elements of reality” (p. 35). This consciousness raising is a journey teachers pursue with students, together interrogating injustices in communities and the world in order to transform the conditions that inform them. Learning to perceive social, political, and economic contradictions often leads to multiple forms of resistance in and out of music classrooms. This chapter explores the following question: What do critical forms of assessment look like in music classrooms that use critical pedagogy and embrace resistance to foster conscientization
AN ANTIMICROBIAL PHTHALATE DERIVATIVE FROM BACILLUS CEREUS, THE SYMBIOTIC BACTERIUM ASSOCIATED WITH A NOVEL ENTOMOPATHOGENIC NEMATODE, RHABDITIS (OSCHEIUS) SP
Objective: To isolate and identify the bioactive metabolites from the culture filtrates of a bacterium (Bacillus cereus) symbiotically associated with a novel entomopathogenic nematode Rhabditis (Oscheius) species.Methods: The bacterium was cultured in three different media and the antimicrobial activity was determined by the well diffusion assay. The ethyl acetate extract of the cell free culture filtrate was then purified by silica gel column chromatography and thin layer chromatography. Identification of the active metabolite was done with HPLC, GC-MS and LC-MS.Results: The cell free culture filtrate of a nematode symbiotic bacterium showed both antibacterial and antifungal activities. Fermentation conditions were standardized and optimum antibacterial activity was observed in tryptic soy broth at 72 h of incubation at 30 °C. When the ethyl acetate extract was purified by silica gel column chromatography and thin layer chromatography, an active fraction was obtained which was subjected to HPLC analysis along with GC-MS and LC-MS leading to the identification of a major compound Bis (2-ethyl hexyl) phthalate. The compound was active against Gram positive bacteria Bacillus subtilis MTCC2756, Staphylococus aureus MTCC902, Gram negative bacteria Escherichia coli MTCC 2622 and fungi such as Aspergillus flavus MTCC277, Candida albicans MTCC183, Fusarium oxysporum MTCC 284, Rhizoctonia solani MTCC 4634.Conclusion: Bis (2-ethyl hexyl) phthalate was identified as one of the metabolites produced by a nematode symbiotic bacterium associated with a novel entomopathogenic nematode Rhabditis (Oscheius) species. Thus similar compounds isolated from novel entomopathogenic bacteria would pave the way for identifying new drugs for the pharmaceutical and agricultural sector.Â
Crystal structure of isobutyl 4-(2-chloro-phenyl)-5-cyano-6-{(E)-[(dimethylamino)-methylidene]amino}-2-methyl-4H-pyran-3-carboxylate
The authors thank Dr Babu Varghese, Senior Scientific Officer SAIF, IIT Madras, India, for carrying out the data collection.Peer reviewedPublisher PD
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Altered Chromatin Occupancy of Master Regulators Underlies Evolutionary Divergence in the Transcriptional Landscape of Erythroid Differentiation
Erythropoiesis is one of the best understood examples of cellular differentiation. Morphologically, erythroid differentiation proceeds in a nearly identical fashion between humans and mice, but recent evidence has shown that networks of gene expression governing this process are divergent between species. We undertook a systematic comparative analysis of six histone modifications and four transcriptional master regulators in primary proerythroblasts and erythroid cell lines to better understand the underlying basis of these transcriptional differences. Our analyses suggest that while chromatin structure across orthologous promoters is strongly conserved, subtle differences are associated with transcriptional divergence between species. Many transcription factor (TF) occupancy sites were poorly conserved across species (∼25% for GATA1, TAL1, and NFE2) but were more conserved between proerythroblasts and cell lines derived from the same species. We found that certain cis-regulatory modules co-occupied by GATA1, TAL1, and KLF1 are under strict evolutionary constraint and localize to genes necessary for erythroid cell identity. More generally, we show that conserved TF occupancy sites are indicative of active regulatory regions and strong gene expression that is sustained during maturation. Our results suggest that evolutionary turnover of TF binding sites associates with changes in the underlying chromatin structure, driving transcriptional divergence. We provide examples of how this framework can be applied to understand epigenomic variation in specific regulatory regions, such as the β-globin gene locus. Our findings have important implications for understanding epigenomic changes that mediate variation in cellular differentiation across species, while also providing a valuable resource for studies of hematopoiesis
Prediction of cutting forces developed during hard turning of hard chrome plated surfaces on EN24 substrate / K. N. Mohandas, C. S. Ramesh and Eshwara Prasad Koorapati
This paper investigates the development of cutting forces during the hard turning of hard chrome plated surfaces on EN24 substrate. The hard turning operation disproves the Merchant's theory of cutting force development during the machining as the hard turning is only a small stock material removal. Various forces produced such as cutting force, feed force and thrust force have been measured during the finish turning. The experimental results have indicated that the feed force is the predominant force out of three different forces developed. This is in good agreement with the available literature. The results obtained from the experimentation were used to predict the optimum cutting conditions in terms of cutting forces. The optimized cutting parameters are feed of 0.08mm/rev, cutting speed of 500rpm and depth of cut of 40jum. The developed mathematical model exhibited satisfactory goodness of the model fit in regression with different PcBN cutting tool inserts. A maximum of 5% variation in the experimental results of the cutting forces when compared with the mathematical model has been observed. This suggests that the developed mathematical model could be employed to predict the cutting forces during hard turning of hard chrome plated surfaces
Differences in Gut Microbiome in Hospitalized Immunocompetent vs. Immunocompromised Children, Including Those With Sickle Cell Disease.
Background: Gut microbial diversity and composition play important roles in health. This cross-sectional study was designed to test the hypothesis that hospitalized children who may be relatively immunocompromised (IC), defined as those with cancer, sickle cell disease (SCD), transplantation, or receiving immunosuppressive therapy) would have decreased microbial diversity, increased Clostridioides difficile colonization and different species composition compared to non-immunocompromised (Non-IC) children admitted to the same pediatric unit. Methods: A stool sample was obtained within 72 h of admission to a single unit at The Children\u27s Hospital at Montefiore, Bronx, NY from March 2016 to February 2017 and the microbiome assessed by 16S rRNA sequencing. C. difficile colonization was assessed by glutamate dehydrogenase antigen and toxin polymerase chain reaction assays. Results: Stool samples were obtained from 69 IC (32 SCD, 19 cancer, 9 transplantation and 9 other) and 37 Non-IC patients. There were no significant differences in microbial alpha diversity and C. difficile colonization comparing IC vs. non-IC patients. Lower alpha diversity, however, was independently associated with the use of proton pump inhibitors or antibiotics, including prophylactic penicillin in patients with SCD. Differences in specific species abundances were observed when comparing IC vs. non-IC patients, particularly children with SCD. Non-IC patients had increased abundance of commensals associated with health including Alistipes putredinis, Alistipes ihumii, Roseburia inulinivorans, Roseburia intestinalis, and Ruminococcus albus (p \u3c 0.005). Conclusions: Antibiotics and proton pump inhibitors, which were more commonly used in IC children, were identified as risk factors for lower microbial diversity. Non-IC patients had higher abundance of several bacterial species associated with health. Longitudinal studies are needed to determine the clinical significance of these differences in gut microbiome
Fluctuation spectrum of fluid membranes coupled to an elastic meshwork: jump of the effective surface tension at the mesh size
We identify a class of composite membranes: fluid bilayers coupled to an
elastic meshwork, that are such that the meshwork's energy is a function
\textit{not} of the real microscopic membrane area ,
but of a \textit{smoothed} membrane's area , which corresponds to the
area of the membrane coarse-grained at the mesh size . We show that the
meshwork modifies the membrane tension both below and above the scale
, inducing a tension-jump . The
predictions of our model account for the fluctuation spectrum of red blood
cells membranes coupled to their cytoskeleton. Our results indicate that the
cytoskeleton might be under extensional stress, which would provide a means to
regulate available membrane area. We also predict an observable tension jump
for membranes decorated with polymer "brushes"
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