Context. Radius and mass measurements of short-period giant planets reveal that many these contain a large amount heavy elements. Although the range inferred metallicities is broad, with more than 100 M ⊕ elements are not rare. This in sharp contrast expectations conventional core-accretion model for origin planets. Aims. The proposed explanations heavy-element enrichment fall short explaining ...

We present a series of systematic abundance measurements for 25 hot DA white dwarfs in the temperature range ~20000-110000K, based on far-UV spectroscopy with STIS/GHRS on HST, IUE and FUSE. Using our latest heavy element blanketed non-LTE stellar atmosphere calculations we have addressed the heavy element abundance patterns making completely objective measurements of abundance values and upper...

By expanding functions of parton fragmentation into a heavy hadron in the inverse of the heavy quark mass m Q we attempt to factorize them into perturbative-and nonperturba-tive parts. In our approach the nonperturbative parts can be defined as matrix elements in heavy quark effective theory, the shape of the functions is predicted by perturbative QCD. In this work we neglect effect at order of...

Environmental toxicants such as toxic metals can alter epigenetic regulatory features such as DNA methylation, histone modification, and non-coding RNA expression. Heavy metals influence gene expression by epigenetic mechanisms and by directly binding to various metal response elements in the target gene promoters. Given the role of epigenetic alterations in regulating genes, there is potential...

The dataset for this article contains geostatistical analysis of heavy metals contamination from limestone samples collected from Ewekoro Formation in the eastern Dahomey basin, Ogun State Nigeria. The samples were manually collected and analysed using Microwave Plasma Atomic Absorption Spectrometer (MPAS). Analysis of the twenty different samples showed different levels of heavy metals concent...

Abundance observations indicate the presence of rapid-neutron capture (i.e., r-process) elements in old Galactic halo and globular cluster stars. Recent observations of the r-process-enriched star BD+17◦3248 include new abundance determinations for the neutron-capture elements Cd I (Z=48), Lu II (Z = 71) and Os II (Z = 76), the first detections of these elements in metal-poor r-process-enriched...

A brief overview of the r-process is given with an emphasis on the observational implications for this process. The conditions required for the major production of the heavy r-process elements (r-elements) with mass numbers A > 130 are discussed based on a generic astrophysical model where matter adiabatically expands from a hot and dense initial state. Nucleosynthesis in the neutrino-driven wi...

Radionuclide and heavy metal content have been monitored systematically since 1996 in eleven of the widespread Black Sea macroalgae species from the Bulgarian Black Sea coast by low level gamma spectroscopy and atomic absorption spectrometry. Tendencies in the concentration variations during the studied period are examined and all obtained data give information about different macrophytic speci...

The bean (Phaseolus vulgaris) stress-related gene number 2 (PvSR2) gene responds to heavy metals but not to other forms of environmental stresses. To elucidate its heavy metal-regulatory mechanism at the transcriptional level, we isolated and characterized the promoter region (-1623/+48) of PvSR2. Deletions from the 5' end revealed that a sequence between -222 and -147 relative to the transcrip...

introduction: heavy metals released from stationaryand mobile origins can be transported in water, air and soil and can be even absorbed by plants, animals and human bodies. trace elements are currently of great environmental concern. nowadays, one of the most important environmental problems is pollution of agricultural soils occurs by heavy metals due to human activities. atmospheric subsiden...