590 research outputs found
Seasonal movements in short-term yield spreads
An abstract for this article is not availableTreasury bills
Private domestic investment in the current business cycle
An abstract for this article is not availableInvestments ; Business cycles
Seasonal adjustment of the money stock : problems and policy implications
An abstract for this article is not availableMoney supply
Factors determining exchange rates : a simple model and empirical tests
An abstract for this article is not availableEquilibrium (Economics)
The behavior of the spread between Treasury bill rates and private money market rates since 1978
An abstract for this article is not available.Money market ; Interest rates
The cause of the dollar depreciation
An abstract for this article is not availableDollar
The behavior of the spread between Treasury bill rates and private money market rates since 1978
An abstract for this article is not available.Money market ; Interest rates
Treasury bill versus private money market yield curves
An abstract for this article is not availableMoney market ; Treasury bills ; Interest rates
Prediction of clinical outcome in glioblastoma using a biologically relevant nine-microRNA signature
Background
Glioblastoma is the most aggressive primary brain tumor, and is associated with a very poor prognosis. In this study we investigated the potential of microRNA expression profiles to predict survival in this challenging disease.
Methods
MicroRNA and mRNA expression data from glioblastoma (n = 475) and grade II and III glioma (n = 178) were accessed from The Cancer Genome Atlas. LASSO regression models were used to identify a prognostic microRNA signature. Functionally relevant targets of microRNAs were determined using microRNA target prediction, experimental validation and correlation of microRNA and mRNA expression data.
Results
A 9-microRNA prognostic signature was identified which stratified patients into risk groups strongly associated with survival (p = 2.26e−09), significant in all glioblastoma subtypes except the non-G-CIMP proneural group. The statistical significance of the microRNA signature was higher than MGMT methylation in temozolomide treated tumors. The 9-microRNA risk score was validated in an independent dataset (p = 4.50e−02) and also stratified patients into high- and low-risk groups in lower grade glioma (p = 5.20e−03). The majority of the 9 microRNAs have been previously linked to glioblastoma biology or treatment response. Integration of the expression patterns of predicted microRNA targets revealed a number of relevant microRNA/target pairs, which were validated in cell lines.
Conclusions
We have identified a novel, biologically relevant microRNA signature that stratifies high- and low-risk patients in glioblastoma. MicroRNA/mRNA interactions identified within the signature point to novel regulatory networks. This is the first study to formulate a survival risk score for glioblastoma which consists of microRNAs associated with glioblastoma biology and/or treatment response, indicating a functionally relevant signatur
Lithium abundances in CEMP stars
Carbon-enhanced metal-poor (CEMP) stars are believed to show the chemical
imprints of more massive stars (M > 0.8 Msun) that are now extinct. In
particular, it is expected that the observed abundance of Li should deviate in
these stars from the standard Spite lithium plateau. We study here a sample of
11 metal-poor stars and a double-lined spectroscopic binary with -1.8 <[Fe/H]<
-3.3 observed with VLT/UVES spectrograph. Among these 12 metal-poor stars,
there are 8 CEMP stars for which we measure or constrain the Li abundance. In
contrast to previous arguments, we demonstrate that an appropriate regime of
dilution permits the existence of "Li-Spite plateau and C-rich" stars, whereas
some of the "Li-depleted and C-rich" stars call for an unidentified additional
depletion mechanism that cannot be explained by dilution alone. We find
evidence that rotation is related to the Li depletion in some CEMP stars.
Additionally, we report on a newly recognized double-lined spectroscopic binary
star in our sample. For this star, we develop a new technique from which
estimates of stellar parameters and luminosity ratios can be derived based on a
high-resolution spectrum alone, without the need for input from evolutionary
models.Comment: 62 pages, 16 figures, accepted for publication in Ap
- …