Natal homing in a marine fish metapopulation.

Identifying natal origins of marine fishes is challenging because of difficulties in conducting mark-recapture studies in marine systems. We used natural geochemical signatures in otoliths (ear bones) to determine natal sources in weakfish (Cynoscion regalis), an estuarine-spawning marine fish, in eastern North America. Spawning site fidelity ranged from 60 to 81%, comparable to estimates of natal homing in birds and anadromous fishes. These data were in contrast to genetic analyses of population structure in weakfish. Our findings highlight the need for consideration of spatial processes in fisheries models and have implications for the design of marine reserves in coastal regions.

Evidence of genocide 7000 BP--Neolithic paradigm and geo-climatic reality.

The early Neolithic fortified settlement of Schletz, Lower Austria is emerging as one of the most interesting sites of Linear Pottery culture excavation in Austria. In the course of systematic investigations carried out since 1983, a plethora of unexpected results have been obtained. Specifically, the human skeletal remains of 67 individuals have been found at the base of an oval trench system. Without exception, these remains are characterized by multiple traumatic lesions as well as carnivore gnaw marks. Demographic analysis presents the picture of the entire population of this early farming settlement having been extinguished. Further, the findings suggest that a genocide scenario may have been responsible for the final demise of this settlement. The age and sex distribution reveals a lack of young females, who are interpreted as having been abducted by aggressors. There is however no direct skeletal evidence of aggressors at the site; in fact, the uniformity of Strontium isotope ratios (HR-ICP-MS analysis) implies that all 67 individuals, who were left unburied for months, were indigenous. Supporting evidence of increased levels of inter-human aggression--possibly caused by a broad wave of migration--comes from other contemporary end linear pottery sites in Germany. Such findings are here discussed in the context of a dramatic geological event in the region of the Black Sea shelf at this time (7.550 BP), which led to the submergence of some 100.000 square kilometers of fertile land, and which might have been responsible for subsequent gradual population movements into the interior of Europe.

Intrapleural topical application of cisplatin with the surgical carrier Vivostat increases the local drug concentration in an immune-competent rat model with malignant pleuromesothelioma.

OBJECTIVE: We sought to investigate whether intrapleural topical application of cisplatin with a surgical carrier has a prolonged local tissue level in comparison with cisplatin solution while reducing systemic toxicity. METHODS: Forty immune-competent Fischer rats were inoculated with 10(6) mesothelioma cells. Ten days later, left pneumonectomy with tumor debulking was performed. Twenty animals underwent local application of cisplatin solution (100 mg/m2), whereas the same quantity of cisplatin was topically applied as a gel with the Vivostat (Vivolution) system in 20 other animals. In each group 5 subgroups of 4 animals were defined according to the harvesting time of blood and tissue samples (2, 4, 24, and 72 hours and 1 week) after local therapy. Platinum concentrations in serum and tissue and systemic toxicity were analyzed. RESULTS: Platinum concentrations in tissue were significantly higher in the gel group (group 1) than in the solution group (group 2) at 1, 3, and 7 days after therapy (1510, 1224, and 1069 pg/mg for group 1 vs 598, 382, and 287 pg/mg for group 2; P = .007, P = .005, and P = .0002, respectively). Laboratory findings showed renal insufficiency in the animals of the solution group at 1 week, with values of 98 mmol/L versus 7.7 mmol/L for urea and 410 mumol/L versus 43 mumol/L for creatinine (P = .02 and P = .01, respectively), which was confirmed by means of pathologic analysis. CONCLUSIONS: Intrapleural administration of cisplatin with the carrier Vivostat significantly provides sustained higher platinum concentrations up to 1 week in tissue in comparison with application of cisplatin solution without conferring systemic toxicity in this model.

Simultaneous multi-element analysis of trace elements in soil samples by means of high-resolution inductively coupled plasma sector field mass spectrometry (SF-ICP-MS).

The potential of SF-ICP-MS for trace element analysis in complex environmental matrices such as soil solutions was investigated. Spectral interferences found in mass spectra of soil matrices are presented in detail. Furthermore, the influences of single components of the soil matrix on the signal intensity of selected elements were studied. Detection limits of different elements are presented with respect to the composition of the matrix. A fast and accurate method for quasi-simultaneous determination of Al, Si, P, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Sr, Mo, Cd, Sn, Hg and Pb in aqueous soil extracts was established.

SI-traceable certification of Cu, Cr, Cd and Pb in sediment and fly ash candidate reference materials.

Many fields in environmental analytical chemistry deal with very low limits and thresholds as set by governmental legislations or transnational regulations. The need for the accuracy, comparability and traceability of analytical measurements in environmental analytical chemistry has significantly increased and total uncertainties are even asked for by accreditation bodies of environmental laboratories. This paper addresses achieving these goals to guarantee accuracy, quality control, quality assurance or validation of a method by means of certified reference materials. The assessment of analytical results in certified reference materials must be as accurate as possible and every single step has to be fully evaluated. This paper presents the SI-traceable certification of Cu, Cr, Cd and Pb contents in geological and environmentally relevant matrices (three sediments and one fly ash sample). Certification was achieved using isotope dilution (ID) ICPMS as a primary method of measurement. In order to reduce significantly the number of analytical steps and intermediate samples a multiple spiking approach was developed. The full methodology is documented and total uncertainty budgets are calculated for all certified values. A non-element specific sample digestion process was optimised. All wet chemical digestion methods examined resulted in a more or less pronounced amount of precipitate. It is demonstrated that these precipitates originate mainly from secondary formation of fluorides (essentially CaF2) and that their formation takes place after isotopic equilibration. The contribution to the total uncertainty of the final values resulting from the formation of such precipitates was in general < 0.1% for all investigated elements. Other sources of uncertainty scrutinised included the moisture content determination, procedural blank determination, cross-contamination from the different spike materials, correction for spectral interferences, instrumental background and deadtime effects, as well as the use of either certified values or IUPAC data in the IDMS equation. The average elemental content in the sediment samples was 30-130 micrograms g-1 for Pb, 0.5-3 micrograms g-1 for Cd and 50-70 micrograms g-1 for Cu. Cr was measured in one sample and was about 60 micrograms g-1. The concentrations in the fly ash sample were up to 2 orders of magnitude higher. Expanded uncertainty for the investigated elements was about 3% (coverae factor k = 2) except for Cr, (measured by high resolution ICPMS), for which the expanded uncertainty was about 7% (k = 2).