Atmospheric observation-based global SF6 emissions - comparison of top-down and bottom-up estimates

Emissions of sulphur hexafluoride (SF6), one of the strongest greenhouse gases on a per molecule basis, are targeted to be collectively reduced under the Kyoto Protocol. Because of its long atmospheric lifetime (≈3000 years), the accumulation of SF6 in the atmosphere is a direct measure of its global emissions. Examination of our extended data set of globally distributed high-precision SF6 observations shows an increase in SF6 abundance from near zero in the 1970s to a global mean of 6.7 ppt by the end of 2008. In-depth evaluation of our long-term data records shows that the global source of SF6 decreased after 1995, most likely due to SF6 emission reductions in industrialised countries, but increased again after 1998. By subtracting those emissions reported by Annex I countries to the United Nations Framework Convention of Climatic Change (UNFCCC) from our observation-inferred SF6 source leaves a surprisingly large gap of more than 70–80% of non-reported SF6 emissions in the last decade

Technische Mechanik

TECHNISCHE MECHANIK Technische Mechanik (-) Einband (-) Widmung an Professor Mohr (-) Titelseite (-) Vorwort ([I]) Inhalt (V) Festigkeits-Lehre (-) Berechnung der Fachwerke ([43]) Theorie des Erddrucks und Berechnung von Futtermauern ([139]) Berechnung der symmetrischen Tonnengewölbe ([139]) Das Seilpolygon mit Anwendung auf discontinuirliche Träger ([181]) Theorie der elastischen Linie und Berechnung der continuirlichen Träger ([217]) Berechnung des elastischen Bogenträgers ([279]) Farbinformation (-) Einband (-

Exotic states in a simple network of nanoelectromechanical oscillators.

Synchronization of oscillators, a phenomenon found in a wide variety of natural and engineered systems, is typically understood through a reduction to a first-order phase model with simplified dynamics. Here, by exploiting the precision and flexibility of nanoelectromechanical systems, we examined the dynamics of a ring of quasi-sinusoidal oscillators at and beyond first order. Beyond first order, we found exotic states of synchronization with highly complex dynamics, including weak chimeras, decoupled states, traveling waves, and inhomogeneous synchronized states. Through theory and experiment, we show that these exotic states rely on complex interactions emerging out of networks with simple linear nearest-neighbor coupling. This work provides insight into the dynamical richness of complex systems with weak nonlinearities and local interactions

Meningeal dissemination in primary CNS lymphoma: prospective evaluation of 282 patients

BACKGROUND: The impact of meningeal dissemination in primary CNS lymphoma (PCNSL) is debated, and the reported frequency varies. We prospectively evaluated the diagnostic value of PCR in comparison with CSF cytomorphology and MRI for diagnosing meningeal dissemination in PCNSL. METHODS: We evaluated 282 patients from a multicenter therapy study for PCNSL for the presence of meningeal dissemination: 205 with CSF cytomorphology, 171 with PCR of the rearranged immunoglobulin heavy-chain genes in CSF, and 217 with cranial MRI. RESULTS: Meningeal dissemination was found in 33 of 205 patients (16%) by cytomorphology, in 19 of 171 (11%) patients evaluated by PCR, and in 8 of 217 patients (4%) by MRI. Considering either of these methods, the relative frequency of meningeal dissemination was 17.4% (49 of 282 patients). PCR was monoclonal in 6 of 19 (32%) samples with positive cytomorphology, 1 of 13 samples (8%) with suspicious cytology, and in 10 of 105 (10%) cytologically negative samples. In 11 samples with positive and 12 with suspicious cytology, PCR showed only a polyclonal pattern. The probability of meningeal dissemination detection was higher in cases with CSF pleocytosis (>5/microL) with an OR of 2.48 (95% CI 1.15-5.34, p = 0.018). CSF protein had no predictive value for meningeal dissemination detection. CONCLUSIONS: We found a low rate of meningeal dissemination in primary CNS lymphoma in this large prospective study. The rate of discordant PCR and cytomorphologic results was high. Thus, the methods should be regarded as complementary. CSF pleocytosis had predictive value for meningeal dissemination detection

Further investigation of confirmed urinary tract infection (UTI) in children under five years: a systematic review.

Background: Further investigation of confirmed UTI in children aims to prevent renal scarring and future complications. Methods: We conducted a systematic review to determine the most effective approach to the further investigation of confirmed urinary tract infection (UTI) in children under five years of age. Results: 73 studies were included. Many studies had methodological limitations or were poorly reported. Effectiveness of further investigations: One study found that routine imaging did not lead to a reduction in recurrent UTIs or renal scarring. Diagnostic accuracy: The studies do not support the use of less invasive tests such as ultrasound as an alternative to renal scintigraphy, either to rule out infection of the upper urinary tract (LR- = 0.57, 95%CI: 0.47, 0.68) and thus to exclude patients from further investigation or to detect renal scarring (LR+ = 3.5, 95% CI: 2.5, 4.8). None of the tests investigated can accurately predict the development of renal scarring. The available evidence supports the consideration of contrast-enhanced ultrasound techniques for detecting vesico-ureteric reflux (VUR), as an alternative to micturating cystourethrography (MCUG) (LR+ = 14.1, 95% CI: 9.5, 20.8; LR- = 0.20, 95%CI: 0.13, 0.29); these techniques have the advantage of not requiring exposure to ionising radiation. Conclusion: There is no evidence to support the clinical effectiveness of routine investigation of children with confirmed UTI. Primary research on the effectiveness, in terms of improved patient outcome, of testing at all stages in the investigation of confirmed urinary tract infection is urgently required