BACKGROUND The chemical assignment of metabolites is crucial to understanding the relation between food composition and biological activity. OBJECTIVE This study was designed to detect and chemically assign sulfur-containing metabolites by using LC-Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) in Allium plants. METHODS Ultrahigh resolution (>250,000 full width at ha...

Maintaining viable populations of salmon in the wild is a primary goal for many conservation and recovery programs. The frequency and extent of connectivity among natal sources defines the demographic and genetic boundaries of a population. Yet, the role that immigration of hatchery-produced adults may play in altering population dynamics and fitness of natural populations remains largely unqua...

The sulfur isotope effect produced by sulfate reducing microbes is commonly used to trace biogeochemical cycles of sulfur and carbon in aquatic and sedimentary environments. To test the contribution of intracellular coupling between carbon and sulfur metabolisms to the overall magnitude of the sulfur isotope effect, this study compared sulfur isotope fractionations by mutants of Desulfovibrio v...

The measurement of isotope ratios in sedimentary rocks deposited over geological time can provide key insights to past environmental change over important intervals in the past. However, it is important to be aware that secondary alteration can overprint the original isotopic records. We demonstrate this principle using high-resolution carbon, sulfur, and oxygen isotope measurements in organic ...

background: the present research has focused on the effect of radioactivity on drinking water from five sites in the region of zahedan city. materials and methods: the measurement of water activity in wells, river and spring has been used as a screening method. the determination of gamma emitters was performed by use the application of gamma spectrometry. results: the values of radium concentra...

We use a 1-D numerical model to study the atmospheric photochemistry of oxygen, methane, and sulfur after the advent of oxygenic photosynthesis. We assume that mass-independent fractionation (MIF) of sulfur isotopes – characteristic of the Archean – was best preserved in sediments when insoluble elemental sulfur (S 8 ) was an important product of atmospheric photochemistry. Efficient S 8 produc...

Rationale Sulfur isotope analysis of organic sulfur-containing molecules has previously been hindered by challenging preparatory chemistry and analytical requirements for large sample sizes. The natural-abundance sulfur isotopic compositions the amino acids, cysteine methionine, have therefore not yet investigated despite potential utility in biomedicine, ecology, oceanography, biogeochemistry,...