Methanotropic microbial communities associated with bubble plumes above gas seeps in the Black Sea

Bubbles evolving from active gas seeps can be traced by hydroacoustic imaging up to 1000 m high in the Black Sea water column. Although methane concentrations are not distinguishable between the water column above the deep seep and reference sites, atmospheric noble gas measurements clearly show the constant input of gases (mainly methane) via seepage into the Black Sea. Archaea (ANME-1, ANME-2) and methanotrophic bacteria detected with specific 16S rRNA-targeted oligonucleotide probes are related to active gas seeps in the oxic and anoxic water column. It is suggested that methane seeps have a much greater influence on the Black Sea methane budget than previously acknowledged and that ANME-1 and ANME-2 are injected via gas bubbles from the sediment into the anoxic water column mediating methane oxidation. Our results show further that only minor amounts of methane evolving from Black Sea gas seeps reach the atmosphere due to the very effective microbial barrier. Hence only major thermodynamically and/or tectonically triggered gas hydrate dissociation has the potential to induce rapid climate changes as suggested by the “clathrate gun hypothesis.

Evidence of Intense Archaeal and Bacterial Methanotrophic Activity in the Black Sea Water Column

In the northwestern Black Sea, methane oxidation rates reveal that above shallow and deep gas seeps methane is removed from the water column as efficiently as it is at sites located off seeps. Hence, seeps should not have a significant impact on the estimated annual flux of ∼4.1 × 10(9) mol methane to the atmosphere [W. S. Reeburgh, B. B. Ward, S. C. Wahlen, K. A. Sandbeck, K. A. Kilatrick, and L. J. Kerkhof, Deep-Sea Res. 38(Suppl. 2):S1189-S1210, 1991]. Both the stable carbon isotopic composition of dissolved methane and the microbial community structure analyzed by fluorescent in situ hybridization provide strong evidence that microbially mediated methane oxidation occurs. At the shelf, strong isotope fractionation was observed above high-intensity seeps. This effect was attributed to bacterial type I and II methanotrophs, which on average accounted for 2.5% of the DAPI (4′,6′-diamidino-2-phenylindole)-stained cells in the whole oxic water column. At deep sites, in the oxic-anoxic transition zone, strong isotopic fractionation of methane overlapped with an increased abundance of Archaea and Bacteria, indicating that these organisms are involved in the oxidation of methane. In underlying anoxic water, we successfully identified the archaeal methanotrophs ANME-1 and ANME-2, eachof which accounted for 3 to 4% of the total cell counts. ANME-1 and ANME-2 appear as single cells in anoxicwater, compared to the sediment, where they may form cell aggregates with sulfate-reducing bacteria (A. Boetius, K. Ravenschlag, C. J. Schubert, D. Rickert, F. Widdel, A. Giesecke, R. Amann, B. B. Jørgensen, U. Witte, and O. Pfannkuche, Nature 407:623-626, 2000; V. J. Orphan, C. H. House, K.-U. Hinrichs, K. D. McKeegan, and E. F. DeLong, Proc. Natl. Acad. Sci. USA 99:7663-7668, 2002)

Valence band discontinuity at the GaN/SiC(0001) heterojunction studied in situ by synchrotron-radiation photoelectron spectroscopy

The valence band discontinuity and the interface formation of the n-type hexagonal GaN/SiC(0 0 0 1) heterointerface have been studied by means of angle-resolved photoelectron spectroscopy using synchrotron radiation. Gallium nitride thin films were grown on SiC(0 0 0 1) substrates by molecular beam epitaxy using either nitrogen plasma or ammonia gas as nitrogen source. The interface properties were investigated in situ by a combination of core level and valence band spectroscopy. The interface formation and the valence band offset of the epitaxial GaN films grown by the two methods have been compared. The GaN/SiC interface shows Si±0.1 eV for the ammonia grown films and 1.10±0.1 eV for the nitrogen plasma grown films. These values are in good agreement with the theoretical prediction and indicate that the band alignment of the GaN/SiC heterojunction is of the staggered type

Perceived impact of the COVID-19 pandemic on child and adolescent psychiatric services after 1 year (February/March 2021): ESCAP CovCAP survey

International audienceIn April 2020, the European Society for Child and Adolescent Psychiatry (ESCAP) Research Academy and the ESCAP Board launched the first questionnaire of the CovCAP longitudinal survey to estimate the impact of COVID-19 on child and adolescent psychiatry (CAP) services in Europe. In this brief report, we present the main findings from the second questionnaire of the survey, one year after the COVID-19 pandemic began to hit Europe (i.e., February/March 2021). While service delivery to patients and their families was affected in a major way (reported by 68%) at the beginning of the pandemic, the majority of respondents (59%) in this second survey only reported a minor impact on care delivery. The use of telemedicine remained widespread (91%) but the proportion of CAP services partially closed or transformed to accommodate COVID-19 patients (59% in 2020) dropped to 20%. On the other hand, the perceived impact on the mental health and psychopathology of children and adolescents dramatically increased from "medium" (> 50%) in 2020 to "strong" or "extreme" (80%) in 2021. Four nosographic entities were particularly impacted: suicidal crises, anxiety disorders, eating disorders and major depressive episodes. Accordingly, this was associated with a substantial increase in the number of referrals or requests for assessments (91% reported an increase in 2021 while 61% reported a decrease in 2020). Finally, heads of the CAP departments expressed strong concerns regarding the management of the long-term consequences of this crisis, especially regarding the provision of care in light of the perceived increase in referrals

Perceived impact of the COVID-19 pandemic on child and adolescent psychiatric services after 1 year (February/March 2021): ESCAP CovCAP survey

In April 2020, the European Society for Child and Adolescent Psychiatry (ESCAP) Research Academy and the ESCAP Board launched the frst questionnaire of the CovCAP longitudinal survey to estimate the impact of COVID-19 on child and adolescent psychiatry (CAP) services in Europe. In this brief report, we present the main fndings from the second questionnaire of the survey, one year after the COVID-19 pandemic began to hit Europe (i.e., February/March 2021). While service delivery to patients and their families was afected in a major way (reported by 68%) at the beginning of the pandemic, the majority of respondents (59%) in this second survey only reported a minor impact on care delivery. The use of telemedicine remained widespread (91%) but the proportion of CAP services partially closed or transformed to accommodate COVID-19 patients (59% in 2020) dropped to 20%. On the other hand, the perceived impact on the mental health and psychopathology of children and adolescents dramatically increased from “medium” (>50%) in 2020 to “strong” or “extreme” (80%) in 2021. Four nosographic entities were particularly impacted: suicidal crises, anxiety disorders, eating disorders and major depressive episodes. Accordingly, this was associated with a substantial increase in the number of referrals or requests for assessments (91% reported an increase in 2021 while 61% reported a decrease in 2020). Finally, heads of the CAP departments expressed strong concerns regarding the management of the long-term consequences of this crisis, especially regarding the provisionof care in light of the perceived increase in referrals