Atmospheric particle evolution during a nighttime atmospheric mercury depletion event in sub-Arctic at Kuujjuarapik/Whapmagoostui, Québec, Canada

International audienceDuring a field experiment at Kuujjuarapik/Whapmagoostui (55.31°N, 77.75°W), Québec, we observed increases of concentrations of particles with diameters larger than 0.3 μm in the ambient air during a nighttime atmospheric mercury depletion event (AMDE). These increases were strongly correlated with decreases of ozone and atmospheric mercury, and we also observed a change in the particle size distribution during this AMDE. Assuming that these phenomena imply either a chemical link or an association through transport, we also studied the nature of this AMDE. We hypothesize that the observed AMDE was a result of an influx of already depleted air masses and that it was not a product of local chemical reactions

Cloning of the mouse BTG3 gene and definition of a new gene family (the BTG family) involved in the negative control of the cell cycle

International audienc

What Is SIMBAD, and What Is It Not?

International audienceThe purpose of the SIMBAD database is to provide the bibliography and some fundamental data on astronomical objects of interest which have been studied in scientific articles. It includes objects of any nature, stars - galaxies - interstellar medium - transient events - etc. SIMBAD is a meta-compilation built from what is published in the literature, and from our expertise on cross-identifications. It is a dynamic database, updated every working day. By construction its content is heterogeneous as data come from any kind of instruments at all wavelengths with any resolution and astrometry, and different names from one publication to another. Thus SIMBAD is not a catalogue, and should not be used as a catalogue. It is not the purpose of SIMBAD to contain “everything”. Especially, lists of uncharacterised sources detected in photometric surveys of any size are usually not processed in SIMBAD. But they are available at CDS in the VizieR database which contains published tables of objects, as well as most very large surveys. The idea now is to use both SIMBAD and VizieR as complementary research tools

Quantitative Real-Time Reverse Transcription-PCR Assay for the Expression of Tob mRNA in Human Colorectal Cancer

OBJECTIVE Tob is a member of Tob/BTG antiproliferative family. To date, Tob expression in human carcinoma using clinical specimens has not been studied in depth except for lung carcinoma and thyroid carcinoma. This study is the first to investigate the expression levels of Tob gene in human colorectal cancer tissues, and their corresponding para-cancerous tissues. The correlation of expression of the Tob gene with clinicopathological characteristics of colorectal cancer was also analyzed. METHODS Quantitative real time RT-PCR was used to detect the expression of Tob mRNA in 31 colorectal cancers. RESULTS Compared with normal tissues, up-regulation of Tob mRNA was observed in 31 colorectal cancer tissues (P =0.020). The expression level of Tob at Dukes C + D phase was higher than Dukes A + B phase, and the difference was signifi cant (P < 0.05). However, in this study, it was found that the expression of Tob mRNA was not related with age, gender, and pathological type of colorectal cancer. CONCLUSION The up-regulation of Tob may be closely associated with tumorigenesis of colorectal carcinoma