ABSTRACT
Marine food-reliant subsistence systems such as those in the African Middle Stone Age (MSA) were not thought to exist in Europe until the much later Mesolithic. Whether this apparent lag reflects taphonomic biases or behavioral distinctions between archaic and modern humans remains much debated. Figueira Brava cave, in the Arrábida range (Portugal), provides an exceptionally well preserved record of Neandertal coastal resource exploitation on a comparable scale to the MSA and dated to ~86 to 106 thousand years ago. The breadth of the subsistence base-pine nuts, marine invertebrates, fish, marine birds and mammals, tortoises, waterfowl, and hoofed game-exceeds that of regional early Holocene sites. Fisher-hunter-gatherer economies are not the preserve of anatomically modern people; by the Last Interglacial, they were in place across the Old World in the appropriate settings.
Subject(s)
Diet , Neanderthals , Animal Shells , Animals , Archaeology , Atlantic Ocean , Birds , Caves , Fishes , Mammals , Nuts , Pinus , Portugal , Seafood , TurtlesABSTRACT
Two competitive immunoassays, a laboratory assay based on microwell plates and a field test based on the use of polystyrene tubes, have been developed for the quantification of thiram in lettuces. Concerning the laboratory assay, the calibration curve for thiram had a linear range of 11 to 90 ng/mL and a detection limit of 5 ng/mL. Precision of the assay presented coefficient of variation values <9% and the recovery of thiram from lettuce averaged 89% across the range of the immunoassay method using 30 min extraction with water/acetone (50:50, v/v). The tube-based method was developed in order that an extract of lettuce, containing thiram at the MRL (8 ppm), would be found on the linear part of the standard curve. The calibration curve for thiram has a linear range of 100 to 800 ng/mL (1.39 to 11.1 ppm in lettuce) and a detection limit of 40 ng/mL.
Subject(s)
Fungicides, Industrial/analysis , Lactuca/chemistry , Pesticide Residues/analysis , Thiram/analysis , Enzyme-Linked Immunosorbent Assay/methods , Reproducibility of Results , Sensitivity and Specificity , Thiram/immunology , Time FactorsABSTRACT
An enzyme-linked immunosorbent assay (ELISA) was developed for the fungicide thiram. Two types of haptens were synthesized. The first type exhibits the two symmetrical N-alkyl dithiocarbamate patterns of thiram with a spacer arm linked to one of the N-methyl terminal group. The second type exhibits one of the two symmetrical N-alkyl dithiocarbamate patterns of thiram with a variable-length spacer arm linked to one sulfur atom. Polyclonal antibodies suitable for thiram detection were obtained from immunization with an hapten of the first type, while haptens of the second type were used as coating antigens to develop a competitive ELISA against thiram. The IC(50) value for thiram was estimated to be 0.24 microg/mL, with a detection limit of 0.03 microg/mL. The assay seems to be thiram-specific since no or little cross-reaction with other dithiocarbamates were observed.
