The Long Term Response of Birds to Climate Change: New Results from a Cold Stage Avifauna in Northern England

The early MIS 3 (55–40 Kyr BP associated with Middle Palaeolithic archaeology) bird remains from Pin Hole, Creswell Crags, Derbyshire, England are analysed in the context of the new dating of the site’s stratigraphy. The analysis is restricted to the material from the early MIS 3 level of the cave because the upper fauna is now known to include Holocene material as well as that from the Late Glacial. The results of the analysis confirm the presence of the taxa, possibly unexpected for a Late Pleistocene glacial deposit including records such as Alpine swift, demoiselle crane and long-legged buzzard with southern and/or eastern distributions today. These taxa are accompanied by more expected ones such as willow ptarmigan /red grouse and rock ptarmigan living today in northern and montane areas. Finally, there are temperate taxa normally requiring trees for nesting such as wood pigeon and grey heron. Therefore, the result of the analysis is that the avifauna of early MIS 3 in England included taxa whose ranges today do not overlap making it a non-analogue community similar to the many steppe-tundra mammalian faunas of the time. The inclusion of more temperate and woodland taxa is discussed in the light that parts of northern Europe may have acted as cryptic northern refugia for some such taxa during the last glacial. These records showing former ranges of taxa are considered in the light of modern phylogeographic studies as these often assume former ranges without considering the fossil record of those taxa. In addition to the anomalous combination of taxa during MIS 3 living in Derbyshire, the individuals of a number of the taxa are different in size and shape to members of the species today probably due to the high carrying capacity of the steppe-tundra.     

Dark starvation and chloroplast function

Summary Mature spinach plants were held in the dark for several days. The photochemical activities and the activity of some enzymes related to NADP reduction were follwed in the chloroplasts isolated from leaves after dark starvation. Photosystem-II, measured by reduction of DPIP, remained stable during 6 days of darkening. The decrease of NADP reduction which appeared after 2 days of starvation was found to be due to protein autolysis rather than inactivation of the photosystems. The stability of photosystem-I was demonstrated by reactivation of NADP reduction after addition of purified ferredoxin and ferredoxin-NADP-reductase. After 4 days of starvation the restoration of the NADP reduction required in addition another, low-molecular-weight factor. From the isolation procedure and from its properties this factor is assumed to be identical with FRS. However, even in the presence of FRS only half of the total activity is restored after 7 days. The activity of the NADP-reducing system is restored in vivo when plants kept for 7 days in the dark are again illuminated.Abbreviations NADP nicotinamide-adenine-dinucleotide phosphate - DPIP 2,6-dichlorophenolindophenol - DCMU (3,4-dichlorophenyl)-1,1-dimethylurea - FRS ferredoxin-reducing-substance     

Impacts on Sirtuin Function and Bioavailability of the Dietary Bioactive Compound Dihydrocoumarin

The plant secondary metabolite and common food additive dihydrocoumarin (DHC) is an inhibitor of the Sirtuin family of NAD⁺-dependent deacetylases. Sirtuins are key regulators of epigenetic processes that maintain silent chromatin in yeast and have been linked to gene expression, metabolism, apoptosis, tumorogenesis and age-related processes in multiple organisms, including humans. Here we report that exposure to the polyphenol DHC led to defects in several Sirtuin-regulated processes in budding yeast including the establishment and maintenance of Sir2p-dependent silencing by causing disassembly of silent chromatin, Hst1p-dependent repression of meiotic-specific genes during the mitotic cell cycle. As both transient and prolonged exposure to environmental and dietary factors have the potential to lead to heritable alterations in epigenetic states and to modulate additional Sirtuin-dependent phenotypes, we examined the bioavailability and digestive stability of DHC using an in vivo rat model and in vitro digestive simulator. Our analyses revealed that DHC was unstable during digestion and could be converted to melilotic acid (MA), which also caused epigenetic defects, albeit less efficiently. Upon ingestion, DHC was observed primarily in intestinal tissues, but did not accumulate over time and was readily cleared from the animals. MA displayed a wider tissue distribution and, in contrast to DHC, was also detected in the blood plasma, interstitial fluid, and urine, implying that the conversion of DHC to the less bioactive compound, MA, occurred efficiently in vivo.     

Das Lungenkrebsrisiko Durch Inhalation von Radon-222-Zerfallsprodukten

Zusammenfassung Es werden die Ergebnisse der in den USA und in der CSSR durchgeführten Erhebungen über die Lungenkrebshäufigkeit bei Uranbergarbeitern gegenübergestellt und verglichen. An Hand dieser Daten wird der Zusammenhang zwischen der beobachteten erhöhten Lungenkrebsmortalität und der durch Rn-Zerfallsprodukte verursachten Strahlenexposition bei diesen Arbeitern diskutiert und der Risikokoeffizient für strahleninduzierten Lungenkrebs abgeschätzt. Der relative Risikokoeffizient stimmt bei beiden Kollektiven von Uranbergarbeitern innerhalb der Vertrauensgrenzen überein und liegt im Bereich von 0,001 bis 0,005 WLM^–1. Demgegenüber besteht zwischen dem abgeleiteten absoluten Risikokoeffizienten von etwa 20±10 (USA-Kollektiv) bzw. 150±50 (CSSR-Kollektiv) zusätzliche Lungenkrebsfälle pro WLM und 10⁶ Personen ein signifikanter Unterschied. Der Einfluß synergistischer bzw. kocancerogener Effekte wird diskutiert. Die Zunahme der Lungenkrebsmortalität mit steigender Exposition ist signifikant verknüpft mit einer Zunahme des kleinzeiligen, undifferenzierten Krebszelltyps.

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The lung cancer risk by inhalation of Rn-222-decay products

Summary The results of surveys in the USA and the CSSR about the lung cancer mortality among uranium miners are compared. The relation between the observed excess lung cancer mortality and the cumulative exposure of these miners by inhaled Rn-daughters is discussed and the risk coefficients for radiation-induced lung cancer are estimated. The relative risk coefficients of both study groups of U-miners agree within the confidence limits and are in the range of 0,001 to 0,005 WLM^–1. The derived absolute risk coefficients of 20±10 (USA group) and 150±50 (CSSR group) additional lung cancer deaths per WLM and 10⁶ miners are, however, significantly different. The influence of synergistic or cocancerogenic actions is discussed. The increase of lung cancer mortality with Rn-exposure is significantly correlated with an increase of the small-cell, undifferentiated type of carcinoma.

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Herrn Prof. Dr. Dr. h. c. mult. B. Rajewsky zum 80. Geburtstag gewidmet.