Holocene paleoenvironmental change inferred from two sediment cores collected in the Tibetan lake Taro Co

The Tibetan Plateau, also known as the ‘‘Water Tower of Asia’’ because of its function as a water storage and supply region, responds dramatically to modern climate changes. Paleoecological shifts inferred from lake sediment archives provide essential insights into past climate changes, and the processes that drove those shifts. This is especially true for studies of lakes in endorheic basins on the Tibetan Plateau, where lake level is regulated pre-dominantly by Monsoon intensity. Such water bodies provide excellent opportunities to reconstruct past changes in humidity. Most paleolimnological investigations of lakes on the Tibetan Plateau, however, have involved the study of a single sediment core, making it difficult to discern between changes caused by local events and those caused by lake-wide or regional processes. Here we present results from a paleolimnological study of Lake Taro Co, a currently closed-basin lake in Central Tibet. We compared a sediment record from the central part of the lake to a record from the near-shore area, and present results of sedimentological and bioindicator (chironomid, diatom, pollen) analyses from both records. Results show three periods of lake-wide ecosystem change ([ca. 5250, 5250–2250 and since about 2250 cal year BP), which reflect a continuous drying trend throughout the Middle and Late Holocene. In addition to this lake-wide trend, we identified two local events in the sediment core from the southeastern, nearshore site. These include (1) a hiatus between 12,400 and 5400 cal year BP and (2) an 1800-year period of distinct paleoenvironmental conditions (5400–3600 cal year BP). We hypothesize that both events were caused by relocation of a river in the southeast sector of the lake’s catchment. We propose that the first relocation caused an erosion event that removed sediment, thereby producing the hiatus. During the following 1800 years, the core site may have been located on the river delta, before another river relocation at 3600 cal year BP established the modern prodelta situation. Our study demonstrates the value of using multiple sediment cores from a lake, to better identify processes that control widespread versus local events

Organisationskultur. Eine Konkretisierung aus systemtheoretischer Perspektive

Kühl S. Organisationskultur. Eine Konkretisierung aus systemtheoretischer Perspektive. Managementforschung. 2018;28(1):7-35.Die Bestimmung des Verhältnisses von Informalität und Organisationskultur bereitet in der Organisationstheorie Schwierigkeiten. Das liegt daran, dass der Begriff Informalität häufig stillschweigend durch den Begriff der Organisationskultur ersetzt wurde, ohne dass dafür eine präzise, abgrenzungsscharfe Definition vorgenommen worden wäre. Unter Rückgriff auf Überlegungen von Dario Rodríguez argumentiert dieser Artikel, dass die beiden Begriffe Organisationskultur und Informalität das gleiche Phänomen bezeichnen: die nichtentschiedenen Entscheidungsprämissen einer Organisation. Dabei wird systematisch zwischen „unentscheidbaren Entscheidungsprämissen“ und „prinzipiell entscheidbaren, aber nicht entschiedenen Entscheidungsprämissen“ unterschieden. Es wird gezeigt, wie sich mit einer präzisen Bestimmung über das Konzept der Entscheidungsprämissen Ordnung in die „wilden Merkmallisten“ der Literatur sowohl über Informalität als auch Organisationskultur bringen lässt und empirische Phänomene genauer erfasst werden können

Autosomal Dominant Mutation in the Signal Peptide of Renin in a Kindred With Anemia, Hyperuricemia, and CKD

Homozygous or compound heterozygous mutations in renin (REN) cause renal tubular dysgenesis, which is characterized by death in utero due to kidney failure and pulmonary hypoplasia. The phenotype resembles the fetopathy caused by angiotensin-converting enzyme inhibitor or angiotensin receptor blocker intake during pregnancy. Recently, heterozygous REN mutations were shown to result in early-onset hyperuricemia, anemia, and chronic kidney disease (CKD). To date, only 3 different heterozygous REN mutations have been published. We report mutation analysis of the REN gene in 39 kindreds with hyperuricemia and CKD who previously tested negative for mutations in the UMOD (uromodulin) and HNF1B (hepatocyte nuclear factor 1 beta) genes. We identified one kindred with a novel thymidine to cytosine mutation at position 28 in the REN complementary DNA, corresponding to a tryptophan to arginine substitution at amino acid 10, which is found within the signal sequence (c.28T>C; p.W10R). On this basis, we conclude that REN mutations are rare events in patients with CKD. Within the kindred, we found affected individuals over 4 generations who carried the novel REN mutation and were characterized by significant anemia, hyperuricemia, and CKD. Anemia was severe and disproportional to the degree of decreased kidney function. Because all heterozygous REN mutations that have been described are localized in the signal sequence, screening of the REN gene for patients with CKD with hyperuricemia and anemia may best be focused on sequencing of exon 1, which encodes the signal peptide. Am J Kidney Dis. 58(5):821-825. Published by Elsevier Inc. on behalf of the National Kidney Foundation, Inc. This is a US Government Work. There are no restrictions on its use