abstract uranium as a natural radioactive heavy metal widely disperses throughout the earth's crust. in many cases, the natural abundance has been re-distributed due to anthropogenic activities, resulting in radionuclide contamination in groundwater and surface soil. uranium through the plant uptake can enter the chain. the degree of speciation of radio nuclides in soils in areas with differing...

fifty street dust samples were collected from southern and eastern parts of tehran, the capitalof iran. samples were collected during summer under dry and stable weather conditions. total concentrationsof copper (cu), cadmium (cd), lead (pb), chromium (cr), nickel (ni), zinc (zn), iron (fe), manganese (mn)and lithium (li) were determined. ten samples were then selected for characterization, met...

the seasonal abundance patterns of the cotton aphid, aphis gossypii glover, in cotton fields at gorgan in northern iran were studied during two growing seasons of 2002 and 2003. the spatial distribution of different developmental stages and morphs of the aphid was described by fitting data to poisson (random) and negative binomial (aggregated) dis-tributions, and calculating the dispersion indi...

the chemical speciation of heavy metals (arsenic, chromium, copper, lead, zinc and tin) in the sediments offormer tin mining catchment bestari jaya, peninsular malaysia was determined by using the latest version of the community bureau of reference, usually called the bcr 3-step sequential extraction procedure. furthermore, a fourth step was introduced for digestion and analysis of the residue....

knowledge of the probable origin and behaviour of arsenic certainly gives valuable insights into the potential for transfer in the environment and of the risks involved in mining sites. sequential extraction analyses are common experiments often used to study the origin and behaviour of potentially toxic elements. the method, however, presents some deficiencies, including labor-intensive proced...

Breaking news leads to situations of fast-paced reporting in social media, producing all kinds of updates related to news stories, albeit with the caveat that some of those early updates tend to be rumours, i.e., information with an unverified status at the time of posting. Flagging information that is unverified can be helpful to avoid the spread of information that may turn out to be false. D...