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The rare earth element concentrations and radiogenic isotope (Sr‐Nd‐Hf) compositions measured in bulk sediment leachates, together with bulk and clay mineralogical data, from two piston cores recovered in the Canadian Beaufort (AMD0214‐02PC) and Chukchi‐Alaskan (HLY0501‐01JPC) margins were studied to investigate changes in the weathering regimes and deep water circulation during the Holocene. The coupled evolutions of the Nd and Hf isotopic compositions (expressed in epsilon units: ɛNd and ɛHf, respectively) are in good agreement with modern seawater and bulk sediment leachate data from Pacific water, Atlantic water, and the Mackenzie River. This agreement supports the idea that boundary exchange and brine formation likely play a significant role in the ɛNd and ɛHf values of the bottom waters in the western Arctic Ocean. The ɛNd and ɛHf records from the Canadian Beaufort and Chukchi‐Alaskan margins reveal changes toward more radiogenic values from the early to late Holocene. Based on the ɛNd and ɛHf records, we suggest that the unradiogenic values are not controlled by water mass provenance and mixing but rather by provenance and a change in the weathering regime in the Mackenzie and Yukon drainage basins during the early to mid‐Holocene. In contrast, the more radiogenic ɛNd and ɛHf values in the Chukchi‐Alaskan margin and the mineralogical records in the late Holocene have primarily been controlled by an increase in the contributions of seawater and detrital particles from the Bering Sea via the Bering Strait inflow, which is likely related to major changes in the Pacific Ocean‐atmospheric dynamics. The first authigenic Nd and Hf isotope records in Holocene sediment cores from the Canadian Beaufort and Chukchi‐Alaskan margins are presentedUnradiogenic Nd‐Hf isotopic values between 11 and 4 ka/cal BP are due to major weathering in the drainage basin of the Yukon/Mackenzie RiversRadiogenic Nd‐Hf isotopic compositions after 4 ka/cal BP reveal an increase in the Atlantic/Pacific water inflows through the Arctic Ocean

Sediments deposited in the lower Argens valley at Fréjus, a well-known Roman Imperial harbor in northwestern Mediterranean, reveal pollutant metal imprints since the Iron Age. Lead, copper and zinc concentrations in sediments above a facies transition from sand (lower) to silt (upper) at 1820–1946cal.BP (65–130cal.CE) are four times higher than in the non-contaminated geochemical background unit at the bottom of the core. These correlated chemical and sedimentological shifts in the ancient marine bay follow the growth of the Augustan city subsequent to the building of the Roman harbor during the late first century BCE. Trace metal enrichment factors (calculated from background concentrations) display a slight but significant increase (1.3 to 1.5) in sediments deposited during the Fréjus protohistoric period, just below the facies transition. This enrichment is corroborated by mean 206Pb/207Pb isotope ratios that vary from 1.179 (±0.002) to 1.193 (±0.002) and 1.202 (±0.002) in the Roman, protohistoric and background units respectively. These findings are the first evidence of pollutant metal release into the lower Argens ria during the protohistoric period, as far as 2600years ago. Lead isotope signatures in the protohistoric sediment layers shed light on several possible geographic origins for ores from which accumulated pollutant metals may originate. These include copper mines in the Alps or the Languedoc regions. Cyprus may also be isotopically invoked as a source that is not supported by archaeological findings and would constitute, if proven true, a new insight regarding metal trades in protohistoric Gaul.

ABSTRACTIn a comparison of 4 second-generation nucleic acid amplification tests performed with self-collected vaginal swab (SCVS) and first-void urine (FVU) specimens from 575 women, SCVS specimens indicated more infections than did FVU specimens in all assays. The prevalence rates were 9% (53/575 patients) for Chlamydia trachomatisand 2% (11/575 patients) for Neisseria gonorrhoeae. The clinical sensitivities for testing SCVS specimens for C. trachomatiswere 98.1% on a Tigris system and 96.2% on a Panther system for the Aptima Combo 2 assay (Hologic Gen-Probe), 98.0% for the RealTime CT/NG assay on an m2000 instrument (Abbott), 90.6% for the ProbeTec CT/GC Qxassay on the Viper system (Becton Dickinson), and 84.6% for the cobas CT/NG assay on the cobas 4800 platform (Roche). Clinical sensitivities for C. trachomatisin FVU specimens were 88.7% (Tigris) and 88.0% (Panther) for the Aptima Combo 2 assay, 76.9% for the RealTime CT/NG assay, 75.5% for the ProbeTec CT/GC Qxassay, and 81.1% for the cobas CT/NG assay. Clinical sensitivities of the assays for N. gonorrhoeae, with limited positive results, ranged from 63.6% to 100%. Specificities for both infections ranged from 98.4 to 100%. Differences in analytical sensitivities and levels of molecular targets in clinical samples but not inhibitors of amplification may explain the differences in clinical sensitivities.

Abstract—The St‐Robert H5 chondrite yields a mineral/whole‐rock Pb‐Pb age of 4565 ± 23 Ma (2σ) comparable to the accepted age of most chondrites. The regression of chondrule data give a similar age of 4566 ± 7 Ma (2σ). These results imply that no major perturbation affected the Pb‐Pb systematics of this meteorite's parent body within the first few billion years following its accretion. Re and Os concentrations along with Os isotopic compositions of whole‐rock fragments, surface fusion crusts and metal phases are also reported. The whole rock measurements for this ordinary chondrite are characterized by high Re/Os ratio coupled with relatively high 187Os/188Os (compared to average ordinary chondrites), that we interpret as a long term Re enrichment. As for most chondrites, no precise geochronological information could be extracted from the Re/Os systematics, although most data plot near the IIIAB reference isochron (Smoliar et al. 1996). From the fusion crust results, we rule out the possibility that atmospheric entry caused the perturbations in the Re‐Os system, since melted crust analysis yields among the most concordant data points. Evidence from metal phases suggests that a very recent process perturbed the isochron, relocating Re from kamacite toward troilite.

Coxiella burnetii appears to be endemic in animals in the Mauricie region of Quebec, and causes some human cases of Q fever annually. Unlike in other rural areas, patients in this study experienced few respiratory symptoms. To determine whether C burnetii pneumonia is underdiagnosed, adults admitted to hospital for community acquired pneumonia were included in a one-year serological study. Significant immunofluorescent antibody (IFA) titres in four of 118 patients with pneumonia (fewer than 4%) were studied. Clinical presentation, standard laboratory tests and epidemiological data did not allow identification of these cases; however, Q fever increased during the warm months. There were no detectable complement fixing (CF) antibodies in these four cases. C burnetii causes few cases of pneumonia in Mauricie. IFA seems to be a more sensitive test than CF.

Q fever, a zoonosis acquired by inhalation of the rickettsia Coxiella burnetii, is rarely diagnosed in Canada. The world incidence has been increasing since 1960, because of progressive dissemination of this microorganism in animal populations, particularly domestic ruminants. Some recent outbreaks were caused by cats. Of 14 cases reported in Quebec between 1989 and the beginning of 1993, nine occurred successively in an 18-month period in the rural region surrounding Trois-Rivières, after contact with livestock or cats. These cases are reported here, with the results of serological screening of the workers of an abattoir where one of the cases worked. Five additional cases reported in Quebec during the same period are briefly reviewed.