The Tropospheric Lifetimes of Halocarbons and Their Reactions with OH Radicals: an Assessment Based on the Concentration of CO-14

Chemical reaction with hydroxyl radicals formed in the troposphere from ozone photolysis in the presence of methane, carbon monoxide and nitrogen oxides provides an important removal mechanism for halocarbons containing C-H and C = C double bonds. The isotropic distribution in atmospheric carbon monoxide was used to quantify the tropospheric hydroxyl radical distribution. Here, this methodology is reevaluated in the light of recent chemical kinetic data evaluations and new understandings gained in the life cycles of methane and carbon monoxide. None of these changes has forced a significant revision in the CO-14 approach. However, it is somewhat more clearly apparent how important basic chemical kinetic data are to the accurate establishment of the tropospheric hydroxyl radical distribution

Observation of molecules produced from a Bose-Einstein condensate

Molecules are created from a Bose-Einstein condensate of atomic 87Rb using a Feshbach resonance. A Stern-Gerlach field is applied, in order to spatially separate the molecules from the remaining atoms. For detection, the molecules are converted back into atoms, again using the Feshbach resonance. The measured position of the molecules yields their magnetic moment. This quantity strongly depends on the magnetic field, thus revealing an avoided crossing of two bound states at a field value slightly below the Feshbach resonance. This avoided crossing is exploited to trap the molecules in one dimension.Comment: 4 pages, 4 figures, minor revison

Presence of an expressed 13-tubulin gene (TUBB) in the HLA class I region may provide the genetic basis for HLA-linked microtubule dysfunction

An expressed beta-tubulin gene (TUBB) has previously been localized to chromosome region 6pter-p21 in man. By using a panel of deletion mutant cell lines and radiation-reduced hybrids containing fragments of chromosome 6, the TUBB locus could be mapped to the HLA class I region at 6p21.3. A long range restriction map including TUBB and several HLA class I genes was then generated by rotating field gel electrophoresis. The results show that TUBB maps to a segment 170-370 kb telomeric of HLA-C. This location suggests that a mutation at the TUBB locus could be the cause for certain forms of HLAlinked microtubule dysfunction, including immotile cilia syndrome

In-situ comparison of the NOy instruments flown in MOZAIC and SPURT

Two aircraft instruments for the measurement of total odd nitrogen (NOy) were compared side by side aboard a Learjet A35 in April 2003 during a campaign of the AFO2000 project SPURT (Spurengastransport in der Tropopausenregion). The instruments albeit employing the same measurement principle (gold converter and chemiluminescence) had different inlet configurations. The ECO-Physics instrument operated by ETH-Zürich in SPURT had the gold converter mounted outside the aircraft, whereas the instrument operated by FZ-Jülich in the European project MOZAIC III (Measurements of ozone, water vapour, carbon monoxide and nitrogen oxides aboard Airbus A340 in-service aircraft) employed a Rosemount probe with 80 cm of FEP-tubing connecting the inlet to the gold converter. The NOy concentrations during the flight ranged between 0.3 and 3 ppb. The two data sets were compared in a blind fashion and each team followed its normal operating procedures. On average, the measurements agreed within 7%, i.e. within the combined uncertainty of the two instruments. This puts an upper limit on potential losses of HNO3 in the Rosemount inlet of the MOZAIC instrument. Larger transient deviations were observed during periods after calibrations and when the aircraft entered the stratosphere. The time lag of the MOZAIC instrument observed in these instances is in accordance with the time constant of the MOZAIC inlet line determined in the laboratory for HNO3

Emotional expression affects the accuracy of gaze perception

Emotional facial expressions are powerful social cues. Here we investigated how emotional expression affects the interpretation of eye gaze direction. Fifty-two observers judged where faces were looking by moving a slider on a measuring bar to the respective position. The faces displayed either an angry, happy, fearful or a neutral expression and were looking either straight at the observer, or were rotated 2°, 4°, 6° or 8° to the left and right. We found that happy faces were interpreted as directed closer to the observer, while fearful and angry faces were interpreted as directed further away. Judgments were most accurate for neutral faces, followed by happy, angry and fearful faces. These findings are discussed on the background of the "self-referential positivity bias”, suggesting that happy faces are preferably interpreted as directed towards the self while negative emotions are interpreted as directed further awa

Optimization of imaging conditions for composition determination by annular dark field STEM

Quantitative scanning transmission electron microscopy (STEM) allows composition determination for nanomaterials at an atomic scale. To improve the accuracy of the results obtained, optimized imaging parameters should be chosen for annular dark field imaging. In a simulation study, we investigate the influence of imaging parameters on the accuracy of the composition determination with the example of ternary III-V semiconductors. It is shown that inner and outer detector angles and semi-convergence angle can be optimized, also in dependence on specimen thickness. Both, a minimum sampling of the image and a minimum electron dose are required. These findings are applied experimentally by using a fast pixelated detector to allow free choice of detector angles

Genes Encoding Structural Proteins of Epidermal Cornification and S100 Calcium-Binding Proteins Form a Gene Complex (“Epidermal Differentiation Complex”) on Human Chromosome 1q21

Chromosome 1 reveals in region 1q21 a most remarkable density of genes that fulfill important functions in terminal differentiation of the human epidermis. These genes encode the cornified envelope precursors loricrin, involucrin, and small proline-rich proteins (SPRR1, SPRR2, and SPRR3), the intermediate filament-associated proteins profilaggrin and trichohyalin, and several S100A calcium-binding proteins. Extending and refining our previous physical map of 1q21 we have now mapped two additional S100A genes as well as the three SPRR subfamilles and resolved the arrangement of involucrin, SPRRs, and loricrin. All genes are linked within 1.9 Mbp of human genomic DNA in the order: S100A10, trichohyalin, profilaggrin, involucrin, SPRR3, SPRR1B, SPRR2A, loricrin, S100A9, S100A8, S100A6. Co-localization of genes expressed late during maturation of epidermal cells together with genes encoding calcium-binding proteins is particularly intriguing since calcium levels tightly control the differentiation of epithelial cells and the expression of genes encoding epidermal structural proteins. Accounting for the close functional cooperation among these structurally and evolutionary related genes, we conclude that these loci constitute a gene complex, for which we propose the name epidermal differentiation complex