Biogeochemical tags in fish: predicting spatial variations in strontium and manganese in Salmo trutta scales using stream water geochemistry

Fish scales of Salmo trutta exhibited regional patterning in Sr and Mn concentrations in major third-order tributaries in a small upland catchment (the Dee catchment in Wales, United Kingdom; drainage area �1800 km2) that appeared to reflect regional variability in catchment geology and stream water chemistry. When baseline signatures in scale element concentrations were established at a number of sites (n = 12) among the upper, middle, and lower regions of the Dee catchment, 73% of fish were classified to their region of capture based on Sr and Mn in scales. However, the regional patterning in scale chemistry was degraded when high-resolution catchment-wide variability in scale element concentrations was predicted using element concentrations in stream water as a proxy for Sr and Mn in scales at 792 sites in first-, second-, and third-order tributaries in the catchment (mean distance between neighbouring sites = 738 m, range = 41�3634 m). This analysis indicated that many locations throughout the catchment could be potential source locations and demonstrates that the initial classification accuracy was artificially inflated. We have illustrated limitations of the site-based study design commonly employed in biogeochemical tagging studies. Future studies should take account of potential variation in baseline signatures at fine geographical scales when determining the accuracy of stock discrimination using biogeochemical tags

Activated protein C resistance in normal pregnancy

No abstract available

The dog cockle, Glycymeris glycymeris (L.), a new annually-resolved sclerochronological archive for the Irish Sea

Cross-dated chronologies derived from internal growth increments in the shells of the long-lived bivalve, the dog cockle Glycymeris glycymeris (Linnaeus, 1758), live-collected from two different sites off the east (1997) and south (2009) coasts of the Isle of Man respectively, are described. The chronologies, developed from ten individuals from each site, were found to be statistically robust (Expressed Population Signal (EPS) = 0.87 and 0.94 respectively) with a significant common growth signal despite their location 27 km apart (R = 0.53; N = 49, P = < 0.0001). The period of common growth between the two chronologies is consistent with the 12-year difference in their dates of collection thus providing evidence of an annual periodicity of growth line formation. Significant positive correlations were identified between the chronology indices from both the southern (R = 0.55, N = 58, P = < 0.0001) and eastern sites (R = 0.64, N = 68, P = < 0.0001) and mean January to September sea surface temperatures. A significant positive correlation was also found between the southern site and the winter North Atlantic Oscillation index (R = 0.43; N = 49, P = 0.0009). These data indicate that annual growth increments in the shells of G. glycymeris have the potential to be used as a scleroclimatological archive

Risk factors for pregnancy associated venous thromboembolism

In an attempt to reduce the incidence of pregnancy associated venous thromboembolism (PA-VTE), some researchers have advocated screening of all women for the factor V(Leiden) mutation during early pregnancy. We have conducted a large retrospective study (over 72,000 deliveries) to determine if this would be useful. Sixty-two objectively confirmed venous thrombotic events (51 DVT, 11 PE) were recorded at two maternity units in the UK. The incidence of DVT was 0.71 per 1000 deliveries (95% CI 0.5-0.9) with 0.50 occurring in the antenatal period (95% CI 0.34-0.66) and 0.21 in the puerperium (95% CI 0.11-0.31). The incidence of PE was 0.15 per 1000 deliveries (95% CI 0.06-0.24), 0.07 antenatal (95% CI 0.01-0.13) and 0.08 in the puerperium (95% CI 0.02-0.14). Of these 62, 50 attended for follow-up and thrombophilia screening. 28% of all episodes of PA-VTE had no clinical risk factor for thrombosis or an identifiable thrombophilic abnormality. Deficiency of antithrombin was identified in 12% of individuals (95% CI 3-21) and the factor V(Leiden) mutation in 8% (95% CI 0.5-15.5). Based on estimates of the prevalence of the factor V(Leiden) mutation in the population, we estimate that the thrombotic risk for a woman during pregnancy or the puerperium with the defect is approximately 1 in 400-500. This figure would not lend support to the idea of random screening for the mutation in early pregnancy

Superficial vein thrombosis: incidence in association with pregnancy and prevalence of thrombophilic defects

Superficial venous thrombotic (SVT) events are a feature of thrombophilic abnormalities, particularly those involving the protein C pathway. We have determined the incidence of SVT associated with pregnancy and the early postpartum period in a retrospective study involving 72 000 deliveries. Fourty-nine cases occurring in 47 individuals were recorded, with an overall incidence of 0.68/1000 deliveries (95% CI 0.48-0.88). None had a previous history of deep vein thrombosis or pulmonary embolism. Most events occurred in the early post-partum period (0.54/1000 deliveries). Twenty-four/fourty-seven were screened for established thrombophilic abnormalities, with only 1 abnormality detected (FVLeiden heterozygote). Thrombophilia may play a minor role in the aetiology of SVT associated with pregnancy, although a larger study is required to confirm this