Bromine from short-lived source gases in the extratropical northern hemispheric upper troposphere and lower stratosphere (UTLS)

We present novel measurements of five short-lived brominated source gases (CH2Br2, CHBr3, CH2ClBr, CHCl2Br and CHClBr2). These rather short-lived gases are an important source of bromine to the stratosphere, where they can lead to depletion of ozone. The measurements have been obtained using an in situ gas chromatography and mass spectrometry (GC–MS) system on board the High Altitude and Long Range Research Aircraft (HALO). The instrument is extremely sensitive due to the use of chemical ionization, allowing detection limits in the lower parts per quadrillion (ppq, 10−15) range. Data from three campaigns using HALO are presented, where the upper troposphere and lower stratosphere (UTLS) of the northern hemispheric mid-to-high latitudes were sampled during winter and during late summer to early fall. We show that an observed decrease with altitude in the stratosphere is consistent with the relative lifetimes of the different compounds. Distributions of the five source gases and total organic bromine just below the tropopause show an increase in mixing ratio with latitude, in particular during polar winter. This increase in mixing ratio is explained by increasing lifetimes at higher latitudes during winter. As the mixing ratios at the extratropical tropopause are generally higher than those derived for the tropical tropopause, extratropical troposphere-to-stratosphere transport will result in elevated levels of organic bromine in comparison to air transported over the tropical tropopause. The observations are compared to model estimates using different emission scenarios. A scenario with emissions mainly confined to low latitudes cannot reproduce the observed latitudinal distributions and will tend to overestimate organic bromine input through the tropical tropopause from CH2Br2 and CHBr3. Consequently, the scenario also overestimates the amount of brominated organic gases in the stratosphere. The two scenarios with the highest overall emissions of CH2Br2 tend to overestimate mixing ratios at the tropical tropopause, but they are in much better agreement with extratropical tropopause mixing ratios. This shows that not only total emissions but also latitudinal distributions in the emissions are of importance. While an increase in tropopause mixing ratios with latitude is reproduced with all emission scenarios during winter, the simulated extratropical tropopause mixing ratios are on average lower than the observations during late summer to fall. We show that a good knowledge of the latitudinal distribution of tropopause mixing ratios and of the fractional contributions of tropical and extratropical air is needed to derive stratospheric inorganic bromine in the lowermost stratosphere from observations. In a sensitivity study we find maximum differences of a factor 2 in inorganic bromine in the lowermost stratosphere from source gas injection derived from observations and model outputs. The discrepancies depend on the emission scenarios and the assumed contributions from different source regions. Using better emission scenarios and reasonable assumptions on fractional contribution from the different source regions, the differences in inorganic bromine from source gas injection between model and observations is usually on the order of 1 ppt or less. We conclude that a good representation of the contributions of different source regions is required in models for a robust assessment of the role of short-lived halogen source gases on ozone depletion in the UTLS

3-dimensional analysis of the effects of osteoplastic cleft surgery on facial morphology

Bei 25 jugendlichen Patienten mit inkompletten bzw. kompletten Lippen-Kiefer-Gaumen-Spalten erfolgte vor sowie 6 Wochen nach Kieferspalt-Osteoplastik die Vermessung definierter Punkte im Mittelgesicht mittels eines dreidimensionalen Systems zur digitalen Fotogrammetrie (3dMD). Für die Messung von Profiländerungen mit Hilfe der Abstände zwischen prä- und postoperativer Gesichtsoberfläche wurden Messpunkte an der Nase ("sbal" subalare, "ac" alare curvature, "al" alare, "prn" pronasale und "sn" subnasale) und an der Oberlippe ("ls" labiale superius, "ch" cheillon) definiert. Zur Bestimmung der Volumendifferenzen wurde zusätzlich zur Oberfläche eine viereckige Fläche mit den Eckpunkten "sn", "sbal", "ch" und "ls" konstruiert ("coons patch"). Die mittleren Abstände zwischen den prä- und postoperativen Oberflächen der Patientengesichter zeigten an allen definierten Messpunkten eine höchst signifikante Profilverschiebung nach anterior. Beim Vergleich von operierten und nicht operierten Seiten ließ sich an den an der Nasenbasis gewählten Messpunkten ("sbal", "ac") eine signifikante postoperative Profiländerung zugunsten der osteoplastisch versorgten Seiten nachweisen. Die zentrofazialen Messpunkte ("sn", "prn") zeigten sowohl nach links- als auch nach rechts- und am deutlichsten nach beidseitiger Osteoplastik im Mittel Profilzugewinne nach anterior. Statistisch signifikante Volumenzugewinne - standardisiert als Volumendifferenzen pro Messflächen – ließen sich nach Osteoplastik im weichgewebigen Profil Nase/Oberlippe nachweisen. Beim Vergleich der operierten mit den nicht operierten Seiten zeigte sich eine schwach signifikante Volumenzunahme pro entsprechender Messfläche zugunsten der osteoplastisch versorgten Gesichtshälften. In der vorliegenden Arbeit gelang es erstmals, statistisch relevante weichgewebige Profiländerungen an Oberlippe und Nase nach Kieferspalt-Osteoplastik sowohl als Abstände zwischen prä- und postoperativen Oberflächen als auch dreidimensional als Volumenänderungen pro Messfläche nachzuweisen. Die Verarbeitung digitaler Rohdaten aus dreidimensionaler fotogrammetrischer Analyse bildet dabei eine verlässliche Grundlage zur Erstellung standardisierter und damit vergleichbarer Messdaten.At 25 adolescent patients with incomplete respectively complete lip-jaw-palatine-clefts the determination of defined landmarks in the midface was performed before and 6 weeks after osteoplastic cleft surgery using a three-dimensional system for digital photogrammetry (3dMD). For the measurement of profile changing by means of distances between pre- and postoperative facial surfaces landmarks were defined at the nose („sbal" subalare, "ac" alare curvature, "al" alare, "prn" pronasale and "sn" subnasale). For the determination of volume differences a foursquare area with the benchmarks "sn", "sbal", "ch" and "ls" was constructed in addition to surface ("coons patch"). The mean distances between the pre- and postoperative facial surfaces of the patients demonstrated at all defined landmarks a highly significant anterior-turned profile displacement. Comparing operated and non operated sides a significant postoperative profile movement could be detected for the benefit of the sides supported with osteoplastic surgery at the landmarks elected at the base of the nose. The centrofacial landmarks ("sn", "prn") presented both after sinistral and dexter and most of all after bilateral osteoplastic surgery average gains in anterior-turned profile displacements. Statistically significant gains in volume – standardized volume differences per measuring surfaces – could be proven in the soft tissue profile at the nose/upper lip after osteoplastic surgery. Comparing operated and non operated sides a poorly statistically significant volume augmentation per corresponding measuring surface appeared in favour of the facial halves supported by osteoplastic surgery. In the presented dissertation it succeeded for the first time to demonstrate statistically relevant profile movements of soft tissue at the upper lip and nose after osteoplastic cleft surgery both as distances between pre- and postoperative surfaces and three-dimensional as changing of volumes per measuring surfaces. The processing of digital row data from three-dimensional photogrammetric survey thereby provides a reliable base for the issue of standardized and for this reason comparable measuring data

Microsurgical reconstruction of the head and neck-Current practice of maxillofacial units in Germany, Austria, and Switzerland

Refinement in microvascular reconstructive techniques over the last 30 years has enabled an increasing number of patients to be rehabilitated for both functional and aesthetic reasons. The purpose of this study was to evaluate different microsurgical practice, including perioperative management, in Germany, Austria, and Switzerland. The D`OSAK collaborative group for Microsurgical Reconstruction developed a detailed questionnaire which was circulated to units in the three countries. The current practice of the departments was evaluated. Thirty-eight questionnaires were completed resulting in a 47.5% response rate. A considerable variation in the number of microsurgical reconstructions per year was noted. In relation to the timing of bony reconstruction, 10 hospitals did reconstructions primarily (26.3%), 19 secondarily (50%) and 9 (23.7%) hospitals used both concepts. In the postoperative course, 15.8% of hospitals use inhibitors of platelet aggregation, most hospitals use low molecular heparin (52.6%) or other heparin products (44.7%). This survey shows variation in the performance, management, and care of microsurgical reconstructions of patients. This is due in part to the microvascular surgeons available in the unit but it is also due to different types of hospitals where various types of care can be performed in these patients needing special perioperative care. textcopyright 2010 European Association for Cranio-Maxillo-Facial Surgery

Bromine from short–lived source gases in the Northern Hemisphere UTLS

We present novel measurements of five short-lived brominated source gases (CH2Br2, CHBr3, CH2ClBr, CHCl2Br and CHClBr2) obtained using a gas chromatograph-mass spectrometer system on board the High Altitude and Long Range Research Aircraft (HALO). The instrument is extremely sensitive due to the use of chemical ionisation, allowing detection limits in the lower parts per quadrillion (10-15) range. Data from three campaigns using the HALO aircraft are presented, where the Upper Troposphere/Lower Stratosphere (UTLS) of the Northern Hemisphere mid to high latitudes were sampled during winter and during late summer to early fall. We show that an observed decrease with altitude in the stratosphere is consistent with the relative lifetimes of the different compounds. Distributions of the five source gases and total organic bromine just below the tropopause shows an increase in mixing ratio with latitude, in particular during polar winter. This increase in mixing ratio is explained by increasing lifetimes at higher latitudes during winter. As the mixing ratio at the extratropical tropopause are generally higher than those derived for the tropical tropopause, extratropical troposphere-to-stratosphere transport will result in elevated levels of organic bromine in comparison to air transported over the tropical tropopause. The observations are compared to model estimates using different emission scenarios. A scenario which has emissions most strongly concentrated to low latitudes cannot reproduce the observed latitudinal distributions and will tend to overestimate bromine input through the tropical tropopause from CH2Br2 and CHBr3. Consequently, the scenario also overestimates the amount of brominated organic gases in the stratosphere. The two scenarios with the highest overall emissions of CH2Br2 tend to overestimate mixing ratios at the tropical tropopause but are in much better agreement with extratropical tropopause values, showing that not only total emissions but also latitudinal distributions in the emissions are of importance. While an increase in tropopause values with latitude is reproduced with all emission scenarios during winter, the simulated extratropical tropopause values are on average lower than the observations during late summer to fall. We show that a good knowledge of the latitudinal distribution of tropopause mixing ratios and of the fractional contributions of tropical and extratropical air is needed to derive stratospheric inorganic bromine in the lowermost stratosphere from observations. Depending on the underlying emission scenario, differences of a factor 2 in reactive bromine derived from observations and model outputs are found for the lowermost stratosphere, based on source gas injection. We conclude that a good representation of the contributions of different source regions is required in models for a robust assessment of the role of short-lived halogen source gases on ozone depletion in the UTLS

Oligomerization and Binding of the Dnmt3a DNA Methyltransferase to Parallel DNA Molecules: HETEROCHROMATIC LOCALIZATION AND ROLE OF Dnmt3L*

Structural studies showed that Dnmt3a has two interfaces for protein-protein interaction in the heterotetrameric Dnmt3a/3L C-terminal domain complex: the RD interface (mediating the Dnmt3a-3a contact) and the FF interface (mediating the Dnmt3a-3L contact). Here, we demonstrate that Dnmt3a-C forms dimers via the FF interface as well, which further oligomerize via their RD interfaces. Each RD interface of the Dnmt3a-C oligomer creates an independent DNA binding site, which allows for binding of separate DNA molecules oriented in parallel. Because Dnmt3L does not have an RD interface, it prevents Dnmt3a oligomerization and binding of more than one DNA molecule. Both interfaces of Dnmt3a are necessary for the heterochromatic localization of the enzyme in cells. Overexpression of Dnmt3L in cells leads to the release of Dnmt3a from heterochromatic regions, which may increase its activity for methylation of euchromatic targets like the differentially methylated regions involved in imprinting

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present