31 research outputs found
Status of the Signals of Opportunity Airborne Demonstrator (SoOp-AD)
Root zone soil moisture (RZSM) is not directly measured by any current satellite instrument, despite its importance as a key link between surface hydrology and deeper processes. Presently, model assimilation of surface measurements or indirect estimates using other methods must be used to estimate this value. Signals of Opportunity (SoOp) methods, exploiting reflected P- and S-band communication satellite signals, have many of the benefits of both active and passive microwave remote sensing. Reutilization of active transmitters, with forward-scattering geometry, presents a strong reflected signal even at orbital altitudes. Microwave radiometry is advantageous as it measures emissivity, which is directly related to dielectric constant and sensitive to water content of soil. Synthetic aperture radar (SAR) is used in P-band (400 MHz) for soil moisture and biomass, but faces issues in obtaining permission to transmit due to spectrum regulations, particularly over North America and Europe. A primary advantage of SAR is excellent spatial resolution. Signals-of-opportunity (SoOp) reflectometry provides a good compromise between radiometry and SAR by providing decent sensitivity and special resolution for RZSM measurements without issues of spectrum access. Further, a SoOp instrument would not be limited to operating in only a few protected frequencies and is also expected to have less susceptibility to radio-frequency interference (RFI). Although advantageous if available, SoOp techniques do not require the ability to demodulate or decode the communication signals. The SoOp instrument is receive only and therefore requires much less electrical power than a SAR and is more similar to a radiometer in receiver architecture. These unique features of SoOp circumvent past obstacles to a spaceborne P-band remote sensing mission and have the potential to enable new RZSM measurements that are not possible with present technology. We will present the latest development status of a SoOp reflectometer airborne demonstrator (SoOp-AD) operating at 250 MHz to take advantage of existing communication satellite. The instrument is currently in laboratory integration and test
Whole-genome landscapes of major melanoma subtypes
Melanoma of the skin is a common cancer only in Europeans, whereas it arises in internal body surfaces (mucosal sites) and on the hands and feet (acral sites) in people throughout the world. Here we report analysis of whole-genome sequences from cutaneous, acral and mucosal subtypes of melanoma. The heavily mutated landscape of coding and non-coding mutations in cutaneous melanoma resolved novel signatures of mutagenesis attributable to ultraviolet radiation. However, acral and mucosal melanomas were dominated by structural changes and mutation signatures of unknown aetiology, not previously identified in melanoma. The number of genes affected by recurrent mutations disrupting non-coding sequences was similar to that affected by recurrent mutations to coding sequences. Significantly mutated genes included BRAF, CDKN2A, NRAS and TP53 in cutaneous melanoma, BRAF, NRAS and NF1 in acral melanoma and SF3B1 in mucosal melanoma. Mutations affecting the TERT promoter were the most frequent of all; however, neither they nor ATRX mutations, which correlate with alternative telomere lengthening, were associated with greater telomere length. Most melanomas had potentially actionable mutations, most in components of the mitogen-activated protein kinase and phosphoinositol kinase pathways. The whole-genome mutation landscape of melanoma reveals diverse carcinogenic processes across its subtypes, some unrelated to sun exposure, and extends potential involvement of the non-coding genome in its pathogenesis
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Manajemen Perilaku Organisasi: Pendayagunaan Sumber Daya MAnusia -4/E.
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Banyak informasi yang telah disajikan di edisi-edisi sebelumnya telah diperjelas dan dimuhtakirkan. Bagian-bagian dalam tiap bab ditingkatkan dengan tambahan baru dan signifikan agar isinya lebih praktis dan bermanfaat dalam situasi dunia dewasa ini. Penulisan ulang kami lakukan dalam bagian-bagianmengenai daur perkembangan dan konsep tentang pendisiplinan yang lebih konstruktif
EZH2 cooperates with DNA methylation to downregulate key tumour suppressors and interferon gene signatures in melanoma
The histone methylase EZH2 is frequently dysregulated in melanoma and is associated with DNA methylation and silencing of genes involved in tumor suppression. In the present study we used ChIP-seq to identify key suppressor genes that are silenced by histone methylation (H3K27me3) in constitutively active EZH2 mutant melanoma and assessed whether these regions were also sites of DNA methylation. The genes identified were validated by their re-expression after treatment with EZH2 and DNA methyltransferase (DNMT) inhibitors. Expression of putative EZH2 target genes were shown to be highly relevant to survival of melanoma patients in clinical datasets. To determine correlates of response to EZH2 inhibitors we screened a panel of 53 melanoma cell lines for drug sensitivity. We compared RNAseq profiles of sensitive to resistant melanoma cells and performed pathway analysis. Sensitivity was associated with strong downregulation of interferon gamma and alpha gene signatures that were reversed by treatment with EZH2 inhibitors. This is consistent with EZH2-driven dedifferentiated, invasive states associated with treatment resistance and defects in antigen presentation. These results suggest that EZH2 inhibitors may be most effectively targeted to immunologically "cold" melanoma to induce both direct cytotoxicity and increase immune responses in the context of checkpoint inhibitor immunotherapy