8,428 research outputs found
Thermodynamic structure of the stratocumulus-capped boundary layer on 7 July, 1987
As part of project First ISCCP Regional Experiment (FIRE), a mission was carried out on 7 July 1987 to study the thermodynamic structure of a boundary layer which is in transition from a clear to a cloudy state. The National Center for Aeronautical Research (NCAR) Electra flew a pattern in tight coordination with the NASA ER-2 aircraft near 122 West, 31.6 North off the coast of California. A description is given here of the thermodynamic structure. The purpose is to derive the entrainment rate and the fluxes of the thermodynamic variables. To this end researchers represent the data in conserved variable diagrams
Report on the Hawaiian Native Claims Second Draft
report on the Hawaiian Native Claims and analysis for compensation or reparations from the
United State
Implications of high-spatial-resolution thermal infrared (Termoskan) data for Mars landing site selection
Thermal infrared observations of Mars from spacecraft provide physical information about the upper thermal skin depth of the surface, which is on the order of a few centimeters in depth and thus very significant for lander site selection. The Termoskan instrument onboard the Soviet Phobos '88 spacecraft acquired the highest spatial-resolution thermal infrared data obtained for Mars, ranging in resolution from 300 m to 3 km per pixel. It simultaneously obtained broadband reflected solar flux data. Although the 6 deg N - 30 deg S Termoskan coverage only slightly overlaps the nominal Mars Pathfinder target range, the implications of Termoskan data for that overlap region and the extrapolations that can be made to other regions give important clues for optimal landing site selection
The role of telomeres and telomerase reverse transcriptase isoforms in pluripotency induction and maintenance
Telomeres are linear guanine-rich DNA structures at the ends of chromosomes. The length of telomeric DNA is actively regulated by a number of mechanisms in highly proliferative cells such as germ cells, cancer cells, and pluripotent stem cells. Telomeric DNA is synthesized by way of the ribonucleoprotein called telomerase containing a reverse transcriptase (TERT) subunit and RNA component (TERC). TERT is highly conserved across species and ubiquitously present in their respective pluripotent cells. Recent studies have uncovered intricate associations between telomeres and the self-renewal and differentiation properties of pluripotent stem cells. Interestingly, the past decade\u27s work indicates that the TERT subunit also has the capacity to modulate mitochondrial function, to remodel chromatin structure, and to participate in key signaling pathways such as the Wnt/β-catenin pathway. Many of these non-canonical functions do not require TERT\u27s catalytic activity, which hints at possible functions for the extensive number of alternatively spliced TERT isoforms that are highly expressed in pluripotent stem cells. In this review, some of the established and potential routes of pluripotency induction and maintenance are highlighted from the perspectives of telomere maintenance, known TERT isoform functions and their complex regulation
Cumulus parameterization theory in terms of feedback and control
June 1974.Includes bibliographical references.Sponsored by NSF GA-33182
Suppression of the imprinted gene NNAT and X-Chromosome gene activation in isogenic human iPS cells
Genetic comparison between human embryonic stem cells and induced pluripotent stem cells has been hampered by genetic variation. To solve this problem, we have developed an isogenic system that allows direct comparison of induced pluripotent stem cells (hiPSCs) to their genetically matched human embryonic stem cells (hESCs). We show that hiPSCs have a highly similar transcriptome to hESCs. Global transcriptional profiling identified 102-154 genes (\u3e2 fold) that showed a difference between isogenic hiPSCs and hESCs. A stringent analysis identified NNAT as a key imprinted gene that was dysregulated in hiPSCs. Furthermore, a disproportionate number of X-chromosome localized genes were over-expressed in female hiPSCs. Our results indicate that despite a remarkably close transcriptome to hESCs, isogenic hiPSCs have alterations in imprinting and regulation of X-chromosome genes. © 2011 Teichroeb et al
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