70 research outputs found

    Ultrahigh field electron cyclotron resonance absorption in In1x_{1-x}Mnx_xAs films

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    We have carried out an ultrahigh field cyclotron resonance study of nn-type In1x_{1-x}Mnx_xAs films, with Mn composition xx ranging from 0 to 12%, grown on GaAs by low temperature molecular beam epitaxy. We observe that the electron cyclotron resonance peak shifts to lower field with increasing xx. A detailed comparison of experimental results with calculations based on a modified Pidgeon-Brown model allows us to estimate the {\em s-d} and {\em p-d} exchange coupling constants, α\alpha and β\beta, for this important III-V dilute magnetic semiconductor system.Comment: 4 pages, 4 figure

    An in vitro study to assess bioaccessibility and bioavailability of calcium from blue whiting (Micromesistius poutassou) fish bone powder

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    peer-reviewedThe aim of this study was to determine how well calcium-rich mineral extracts derived from blue whiting fish bone powders compare with existing calcium sources (commercially available fish bone supplement, calcium carbonate and milk powder) in terms of physicochemical properties, in vitro bioaccessibility and bioavailability using simulated gastrointestinal tract treatment and a Caco-2 cell culture model. Blue whiting calcium-rich fish bone powders (A to E) were supplied by Bio-marine Ingredients Ireland (BII) and a commercial calcium-rich fish bone powder was used as the positive control F. The BII calcium-rich fish bone powders analysed through atomic emission spectrometry were shown to have similar levels of mineral content in comparison with powder F. Solubility and rheology tests were performed on the rehydrated powders. The pH of BII calcium-rich fish bone powders in water solution (10% w/v) ranged from 6.96 to 9.09 compared to control F (pH 7.33). Following simulated oral, gastric and duodenal in vitro digestion using the COST INFOGEST standardised static adult digestion method, the fish powders A, E and F showed higher values of soluble ionic calcium than rehydrated milk powder. We compared in vitro bioavailability of the powders using the Caco-2 cell line to test the effects of calcium on human colonic epithelial cells, which confirmed that calcium from blue whiting fish bone was more bioavailable than calcium from milk and calcium carbonate. These data indicate that calcium-rich blue whiting fish bone powder compares well with existing calcium sources, in terms of physicochemical properties, bioaccessibility and bioavailability

    Co-culture of mechanically injured cartilage with joint capsule tissue alters chondrocyte expression patterns and increases ADAMTS5 production

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    We studied changes in chondrocyte gene expression, aggrecan degradation, and aggrecanase production and activity in normal and mechanically injured cartilage co-cultured with joint capsule tissue. Chondrocyte expression of 21 genes was measured at 1, 2, 4, 6, 12, and 24 h after treatment; clustering analysis enabled identification of co-expression profiles. Aggrecan fragments retained in cartilage and released to medium and loss of cartilage sGAG were quantified. Increased expression of MMP-13 and ADAMTS4 clustered with effects of co-culture, while increased expression of ADAMTS5, MMP-3, TGF-β, c-fos, c-jun clustered with cartilage injury. ADAMTS5 protein within cartilage (immunohistochemistry) increased following injury and with co-culture. Cartilage sGAG decreased over 16-days, most severely following injury plus co-culture. Cartilage aggrecan was cleaved at aggrecanase sites in the interglobular and C-terminal domains, resulting in loss of the G3 domain, especially after injury plus co-culture. Together, these results support the hypothesis that interactions between injured cartilage and other joint tissues are important in matrix catabolism after joint injury

    Miswired Enhancer Logic Drives a Cancer of the Muscle Lineage.

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    Core regulatory transcription factors (CR TFs) establish enhancers with logical ordering during embryogenesis and development. Here we report that in fusion-positive rhabdomyosarcoma, a cancer of the muscle lineage, the chief oncogene PAX3-FOXO1 is driven by a translocated FOXO1 super enhancer (SE) restricted to a late stage of myogenesis. Using chromatin conformation capture techniques, we demonstrate that the extensive FOXO1 cis-regulatory domain interacts with PAX3. Furthermore, RNA sequencing and chromatin immunoprecipitation sequencing data in tumors bearing rare PAX translocations implicate enhancer miswiring across all fusion-positive tumors. HiChIP of H3K27ac showed connectivity between the FOXO1 SE, additional intra-domain enhancers, and the PAX3 promoter. We show that PAX3-FOXO1 transcription is diminished when this network of enhancers is ablated by CRISPR. Our data reveal a hijacked enhancer network that disrupts the stepwise CR TF logic of normal skeletal muscle development (PAX3 to MYOD to MYOG), replacing it with an "infinite loop" enhancer logic that locks rhabdomyosarcoma in an undifferentiated stage

    Histone hyperacetylation disrupts core gene regulatory architecture in rhabdomyosarcoma

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    Core regulatory transcription factors (CR TFs) orchestrate the placement of super-enhancers (SEs) to activate transcription of cell-identity specifying gene networks, and are critical in promoting cancer. Here, we define the core regulatory circuitry of rhabdomyosarcoma and identify critical CR TF dependencies. These CR TFs build SEs that have the highest levels of histone acetylation, yet paradoxically the same SEs also harbor the greatest amounts of histone deacetylases. We find that hyperacetylation selectively halts CR TF transcription. To investigate the architectural determinants of this phenotype, we used absolute quantification of architecture (AQuA) HiChIP, which revealed erosion of native SE contacts, and aberrant spreading of contacts that involved histone acetylation. Hyperacetylation removes RNA polymerase II (RNA Pol II) from core regulatory genetic elements, and eliminates RNA Pol II but not BRD4 phase condensates. This study identifies an SE-specific requirement for balancing histone modification states to maintain SE architecture and CR TF transcription

    Pipeline Milking Systems for New York Dairy Farms, investment, Operating Costs, and Farmer Experience

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    A.E. Res. 1
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