Watching Eyes - Effekte an Recyclingsammelstellen

Weniger unsachgemässe Abfallentsorgung dank Watching Eyes – dies war die These unseres Feldexperiments. In fünf Gemeinden der Region Bern und Olten wurde während drei Monaten die Wirkung von aufklebbaren Augenpaaren (sog. „Watching Eyes“) auf die unsachgemässe Abfallentsorgung bei Recyclingsammelstellen getestet. Die Menge des Abfalls konnte durch Watching Eyes um bis zu 35 % reduziert werden. Ebenfalls bestätigt wurden die zusätzlichen Erwartungen, dass an Unterflur - Containertypen und an offen einsehbaren Sammelstellen weniger Müll unsachgemäss abgestellt wird. Alle Erkenntnisse passen in die Theorie, dass Benutzer der Sammelstellen sich eher normkonform verhalten, wenn sie sich beobachtet fühlen. Ausserdem macht diese Forschungsarbeit Hoffnung, dass Watching Eyes für ein gesellschaftsrelevantes Problem, die unsachgerechte Abfallentsorgung, Hilfestellung bieten können. Watching Eyes - Aufkleber entfalten ihren grössten Effekt auf soziales Verhalten bei dauerhafter Anwendung. Dieser Effekt vermag die illegal deponierten Müllmengen an Recyclingsammelstellen um rund ein Drittel zu reduzieren. Weiter kann Gemeinden empfohlen werden, in Unterfluranlagen zu investieren und von den alten, traditionellen Containern abzusehen, da dadurch die Menge deponierten Abfalls deutlich reduziert werden kann.

Feasibility of stereotactic MRI-based image guidance for the treatment of vascular malformations: a phantom study.

PURPOSE Treatment of vascular malformations requires the placement of a needle within vessels which may be as small as 1 mm, with the current state of the art relying exclusively on two-dimensional fluoroscopy images for guidance. We hypothesize that the combination of stereotactic image guidance with existing targeting methods will result in faster and more reproducible needle placements, as well as reduced radiationexposure, when compared to standard methods based on fluoroscopy alone. METHODS The proposed navigation approach was evaluated in a phantom experiment designed to allow direct comparison with the conventional method. An anatomical phantom of the left forearm was constructed, including an independent control mechanism to indicate the attainment of the target position. Three interventionalists (one inexperienced, two of them frequently practice the conventional fluoroscopic technique) performed 45 targeting attempts utilizing the combined and 45 targeting attempts utilizing the standard approaches. RESULTS In all 45 attempts, the users were able to reach the target when utilizing the combined approach. In two cases, targeting was stopped after 15 min without reaching the target when utilizing only the C-arm. The inexperienced user was faster when utilizing the combined approach and applied significantly less radiation than when utilizing the conventional approach. Conversely, both experienced users were faster when using the conventional approach, in one case significantly so, with no significant difference in radiation dose when compared to the combined approach. CONCLUSIONS This work presents an initial evaluation of a combined navigation fluoroscopy targeting technique in a phantom study. The results suggest that, especially for inexperienced interventionalists, navigation may help to reduce the time and the radiation dose. Future work will focus on the improvement and clinical evaluation of the proposed method.

Über zwei Kalktuffbildungen in Gudbrandsdalen (Norwegen), mit Bemerkungen über die postglaciale Geologie unserer Gebirgsthäler

Von Axel Blytt

Zur Geschichte der Nordeuropäischen, besonders der Norwegischen Flora

Von Axel Blytt

Zircons, isotope ratios and element analyses from tonalite and oxide gabbro of the mid-ocean ridge from ODP Hole 176-735B

A limiting factor in the accuracy and precision of U/Pb zircon dates is accurate correction for initial disequilibrium in the 238U and 235U decay chains. The longest-lived-and therefore most abundant-intermediate daughter product in the 235U isotopic decay chain is 231Pa (T1/2 = 32.71 ka), and the partitioning behavior of Pa in zircon is not well constrained. Here we report high-precision thermal ionization mass spectrometry (TIMS) U-Pb zircon data from two samples from Ocean Drilling Program (ODP) Hole 735B, which show evidence for incorporation of excess 231Pa during zircon crystallization. The most precise analyses from the two samples have consistent Th-corrected 206Pb/238U dates with weighted means of 11.9325 ± 0.0039 Ma (n = 9) and 11.920 ± 0.011 Ma (n = 4), but distinctly older 207Pb/235U dates that vary from 12.330 ± 0.048 Ma to 12.140 ± 0.044 Ma and 12.03 ± 0.24 to 12.40 ± 0.27 Ma, respectively. If the excess 207Pb is due to variable initial excess 231Pa, calculated initial (231Pa)/(235U) activity ratios for the two samples range from 5.6 ± 1.0 to 9.6 ± 1.1 and 3.5 ± 5.2 to 11.4 ± 5.8. The data from the more precisely dated sample yields estimated DPazircon/DUzircon from 2.2-3.8 and 5.6-9.6, assuming (231Pa)/(235U) of the melt equal to the global average of recently erupted mid-ocean ridge basaltic glasses or secular equilibrium, respectively. High precision ID-TIMS analyses from nine additional samples from Hole 735B and nearby Hole 1105A suggest similar partitioning. The lower range of DPazircon/DUzircon is consistent with ion microprobe measurements of 231Pa in zircons from Holocene and Pleistocene rhyolitic eruptions (Schmitt (2007; doi:10.2138/am.2007.2449) and Schmitt (2011; doi:10.1146/annurev-earth-040610-133330)). The data suggest that 231Pa is preferentially incorporated during zircon crystallization over a range of magmatic compositions, and excess initial 231Pa may be more common in zircons than acknowledged. The degree of initial disequilibrium in the 235U decay chain suggested by the data from this study, and other recent high precision datasets, leads to resolvable discordance in high precision dates of Cenozoic to Mesozoic zircons. Minor discordance in zircons of this age may therefore reflect initial excess 231Pa and does not require either inheritance or Pb loss.