Die katholischen Missionen in den deutschen Schutzgebieten

von J. Schmidli

A trajectory-based estimate of the tropospheric ozone column using the residual method

We estimate the tropospheric column ozone using a forward trajectory model to increase the horizontal resolution of the Aura Microwave Limb Sounder (MLS) derived stratospheric column ozone. Subtracting the MLS stratospheric column from Ozone Monitoring Instrument total column measurements gives the trajectory enhanced tropospheric ozone residual (TTOR). Because of different tropopause definitions, we validate the basic residual technique by computing the 200-hPa-to-surface column and comparing it to the same product from ozonesondes and Tropospheric Emission Spectrometer measurements. Comparisons show good agreement in the tropics and reasonable agreement at middle latitudes, but there is a persistent low bias in the TTOR that may be due to a slight high bias in MLS stratospheric column. With the improved stratospheric column resolution, we note a strong correlation of extratropical tropospheric ozone column anomalies with probable troposphere-stratosphere exchange events or folds. The folds can be identified by their colocation with strong horizontal tropopause gradients. TTOR anomalies due to folds may be mistaken for pollution events since folds often occur in the Atlantic and Pacific pollution corridors. We also compare the 200-hPa-to-surface column with Global Modeling Initiative chemical model estimates of the same quantity. While the tropical comparisons are good, we note that chemical model variations in 200-hPa-to-surface column at middle latitudes are much smaller than seen in the TTOR

Virus Discovery in Desert Tortoise Fecal Samples: Novel Circular Single-Stranded DNA Viruses

The Sonoran Desert tortoise Gopherus morafkai is adapted to the desert, and plays an important ecological role in this environment. There is limited information on the viral diversity associated with tortoises (family Testudinidae), and to date no DNA virus has been identified associated with these animals. This study aimed to assess the diversity of DNA viruses associated with the Sonoran Desert tortoise by sampling their fecal matter. A viral metagenomics approach was used to identify the DNA viruses in fecal samples from wild Sonoran Desert tortoises in Arizona, USA. In total, 156 novel single-stranded DNA viruses were identified from 40 fecal samples. Those belonged to two known viral families, the Genomoviridae (n = 27) and Microviridae (n = 119). In addition, 10 genomes were recovered that belong to the unclassified group of circular-replication associated protein encoding single-stranded (CRESS) DNA virus and five circular molecules encoding viral-like proteins

ATP-competitive, marine derived natural products that target the DEAD box helicase, eIF4A

Activation of translation initiation is a common trait of cancer cells. Formation of the heterotrimeric eukaryotic initiation factor F (eIF4F) complex is the rate-limiting step in 5' m7GpppN cap-dependent translation. This trimeric complex includes the eIF4E cap binding protein, the eIF4G scaffolding protein, and the DEAD box RNA helicase eIF4A. eIF4A is an ATP-dependent helicase and because it is the only enzyme in the eIF4F complex, it has been shown to be a potential therapeutic target for a variety of malignancies. To this end, we have used a simple ATPase biochemical screen to survey several hundred marine and terrestrial derived natural products. Herein, we report the discovery of two natural products from marine sources, elisabatin A (1) and allolaurinterol (2), which show low mu M inhibition of eIF4A ATPase activity. Enzymological analyses revealed 1 and 2 to be ATP-competitive, and cellular evaluations showed reasonable cytotoxicity against A549 (lung cancer) and MDA-MA-468 (breast cancer) cell lines. However, only compound 2 showed potent inhibition of helicase activity congruent with its ATPase inhibitory activity. (C) 2017 Elsevier Ltd. All rights reserved.University of Arizona; National Institutes of Health (NIH) Training Grant [T32 GM008804, T32 HL007249]; National Institute of Environmental Health Sciences Training Grant [T32 ES007091]24 month embargo; available online 19 July 2017.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]