The effect of magmatic activity on hydrothermal venting along the superfast-spreading East pacific rise.

A survey of hydrothermal activity along the superfast-spreading (approximately 150 millimeters per year) East Pacific Rise shows that hydrothermal plumes overlay approximately 60 percent of the ridge crest between 13 degrees 50' and 18 degrees 40'S, a plume abundance nearly twice that known from any other rige portion of comparable length. Plumes were most abundant where the axial cross section is inflated and an axial magma chamber is present. Plumes with high ratios of volatile ((3)He, CH(4), and H(2)S) to nonvolatile (Mn and Fe) species marked where hydrothermal circulation has been perturbed by recent magmatic activity. The high proportion of volatile-rich plumes observed implies that such episodes are more frequent here than on slower spreading ridges.

Long non-coding RNA repertoire and open chromatin regions constitute midbrain dopaminergic neuron - specific molecular signatures.

Midbrain dopaminergic (DA) neurons are involved in diverse neurological functions, including control of movements, emotions or reward. In turn, their dysfunctions cause severe clinical manifestations in humans, such as the appearance of motor and cognitive symptoms in Parkinson's Disease. The physiology and pathophysiology of these neurons are widely studied, mostly with respect to molecular mechanisms implicating protein-coding genes. In contrast, the contribution of non-coding elements of the genome to DA neuron function is poorly investigated. In this study, we isolated DA neurons from E14.5 ventral mesencephalons in mice, and used RNA-seq and ATAC-seq to establish and describe repertoires of long non-coding RNAs (lncRNAs) and putative DNA regulatory regions specific to this neuronal population. We identified 1,294 lncRNAs constituting the repertoire of DA neurons, among which 939 were novel. Most of them were not found in hindbrain serotonergic (5-HT) neurons, indicating a high degree of cell-specificity. This feature was also observed regarding open chromatin regions, as 39% of the ATAC-seq peaks from the DA repertoire were not detected in the 5-HT neurons. Our work provides for the first time DA-specific catalogues of non-coding elements of the genome that will undoubtedly participate in deepening our knowledge regarding DA neuronal development and dysfunctions.

Partitioning of copper at concentrations below the marine water quality criteria.

Partitioning of Cu between the aqueous and particulate phases and among their components was examined in six ambient Puget Sound, Washington State, USA, samples (6-10 nM Cu). Most of the particulate Cu (4-12% of the total Cu) was associated with particulate organic matter, and resulted in distribution coefficients (Kd) ranging between 10(4.55) and 10(5.1). For the dissolved phase, the portion of Cu extracted by C18-packed cartridges averaged 44% (+11%). Radioactive 64Cu was added to these samples to total stable Cu concentrations (17-33 nM). After 24 h of equilibration, the portion of 64Cu associated with the particulate matter in five of the six samples (Kd between 10(4.7) and 10(5.3) was an average of 70% higher than that of natural Cu in the ambient samples. In contrast, only 19 +/- 7% of the 64Cu was extracted by C18-packed cartridges. The partitioning of natural Cu and 64Cu onto particles was not significantly different when the equilibria were based on dissolved Cu passing through the C18 cartridges. Further research is warranted on utilizing the hydrophilic component of the dissolved phase as a parameter on which water quality criteria are based.

Pseudomonas putida as the dominant toluene-degrading bacterial species during air decontamination by biofiltration.

The microbial communities established in three laboratory-scale compost matrix biofilters fed with toluene were characterized. The biofilters were operated for 7 weeks at inlet concentrations of toluene ranging over 250-500 ppm with daily irrigation, using a nutrient solution containing variable concentrations of nitrogen, supplied as urea, and other inorganic salts. The indigenous microflora of the compost included toluene-degrading species, making inoculation unnecessary. The numerically predominant toluene-degrading strains were isolated from the most diluted positive wells of most-probable-number counts on mineral medium with toluene as sole carbon source and identified by rRNA 16S gene sequencing. On the basis of sequence similarity, all the isolated strains were assigned to the species Pseudomonas putida, although some variations were observed in their respective sequences. It is concluded that the mode of biofilter operation including a daily supply of non-carbon nutrients created an environment favoring the constant numerical predominance of this fast-growing toluene-degrading species.