154 research outputs found
The interplay between oil and food commodity prices: Has It changed over time?
Using time-varying BVARs, we find that oil price increases caused by oil supply shocks did not affect food commodity prices before the start of the millennium, but had positive spillover effects in more recent periods. Likewise, shortfalls in global food commodity supply ‒ resulting from bad harvests ‒ have positive effects on crude oil prices since the early 2000s, in contrast to the preceding era. Remarkably, we also document greater spillover effects of both supply shocks on metals and minerals commodity prices in recent periods, as well as a stronger impact on the own price compared to earlier decades. This (simultaneous) time variation of commodity price dynamics cannot be explained by the biofuels revolution and is more likely the consequence of heightened informational frictions and information discovery in more globalized and financialized commodity markets
Role of nitrogen lewis basicity in boronate affinity chromatography of nucleosides. Anal
Urinary modified nucleosides have a potential role as cancer biomarkers, and most of the methods used in their study have utilized low-pressure phenylboronate affinity chromatography materials for the purification of the cisdiol-containing nucleosides. In this study, a boronate HPLC column was surprisingly shown not to trap the nucleosides as would be expected from experience with the classic Affigel 601 resin but showed only partial selectivity toward cis-diol groups while other groups exhibited better retention. In aprotic conditions, trapping of nucleosides was possible; however, the selectivity toward cis-diol-containing compounds was lost with the Lewis basicity of available nitrogens being the main determinant of retention. The experimental findings are compared to and confirmed by DFT calculations. Modified nucleosides are naturally occurring modifications of the "normal" nucleosides. They have various roles within many nucleic acids but are mainly found in transfer RNA. They are excreted from the body via the urine as they cannot be salvaged; moreover, some are toxic when allowed to accumulate. Many past reports have investigated the modified nucleosides as potential cancer biomarkers and indicate considerable promise. [1][2][3][4][5] The methodologies used in these studies are wide ranging; however, since the introduction of boronate affinity chromatography as a ribonucleoside-selective cleanup step, on Affi-Gel 601 (Bio-Rad), utilized by Gehrke et al., 1,2 most research employed this off-line cleanup step process in the analysis. The subsequent identification/quantification of the ribonucleosides was almost exclusively carried out via RPLC-UV methods. More recently, some CE-UV methods have also been developed. [6][7][8][9] The further potential/ demand to obtain unambiguous identification via mass spectrometric detection led to the development of some off-line boronate chromatography GC/MS procedures. 3,5,10 However, the most natural choice for the analysis of the prepurified urinary nucleosides analysis is found in LC-MS. 11 Yet, the development of LC-MS procedures for urinary nucleosides only advanced 12 when electrospray mass spectrometry (ESI-MS) became available. Past studies by our group have considered the cleanup samples prior to ESI-MS analysis, 13 the optimization of the detection conditions, 14 comparison of various mass spectrometric methods, 15 and identification of the excreted nucleosides. 16,17 Other groups have taken advantage of mass spectrometry in the study of these compounds
A cis-regulatory element regulates ERAP2 expression through autoimmune disease risk SNPs
Single-nucleotide polymorphisms (SNPs) near the ERAP2 gene are associated with various autoimmune conditions, as well as protection against lethal infections. Due to high linkage disequilibrium, numerous trait-associated SNPs are correlated with ERAP2 expression; however, their functional mechanisms remain unidentified. We show by reciprocal allelic replacement that ERAP2 expression is directly controlled by the splice region variant rs2248374. However, disease-associated variants in the downstream LNPEP gene promoter are independently associated with ERAP2 expression. Allele-specific conformation capture assays revealed long-range chromatin contacts between the gene promoters of LNPEP and ERAP2 and showed that interactions were stronger in patients carrying the alleles that increase susceptibility to autoimmune diseases. Replacing the SNPs in the LNPEP promoter by reference sequences lowered ERAP2 expression. These findings show that multiple SNPs act in concert to regulate ERAP2 expression and that disease-associated variants can convert a gene promoter region into a potent enhancer of a distal gene
Infrared spectra, relative stability and **ab initio** calculations of the CH3Cl...HCl van der Waals complex observed in liquefied argon
Vibrational spectra and relative stability of the Van der Waals complexes formed between cis-2-butene, trans-2-butene, 2-methyl-propene and HCl: a FTIR and density functional study
Vibrational analysis of the van der Waals complexes between vinyl fluoride and hydrogen chloride in liquefied argon
Equilibrium geometry and vibrational frequencies of the 1:2 Van der Waals complexes between methyl chloride and hydrogen chloride
Vibrational spectra and relative stability of the Van der Waals complexes of boron trifluoride with **cis**-2-butene, **trans**-2-butene and 2-methyl propene
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