40 research outputs found

    Macroecology of methane-oxidizing bacteria: the β-diversity of pmoA genotypes in tropical and subtropical rice paddies

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    Studies addressing microbial biogeography have increased during the past decade, but research on microbial distribution patterns is still in its infancies, and many aspects are only poorly understood. Here, we compared the methanotroph community in paddy soils sampled in Indonesia, Vietnam, China and Italy, focusing on the distance-decay relationship. We used the pmoA gene as marker for methanotroph diversity in terminal restriction fragment length polymorphism, microarray and pyrosequencing approaches. We could observe a significant increase of -diversity with geographical distance across continents (12000km). Measured environmental parameters explained only a small amount of data variation, and we found no evidence for dispersal limitation. Thus, we propose historical contingencies being responsible for the observed patterns. Furthermore, we performed an in-depth analysis of type II methanotroph pmoA distribution at the sequence level. We used ordination analysis to project sequence dissimilarities into a three-dimensional space (multidimensional scaling). The ordination suggests that type II methanotrophs in paddy fields can be divided into five major groups. However, these groups were found to be distributed in all soils independent of the geographic origin. By including tropical field sites (Indonesia and Vietnam) into the analysis, we further observed the first paddy fields harbouring a methanotroph community depleted in type II methanotrophs

    Population dynamics and range shifts of moose (Alces alces) during the Late Quaternary

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    Aim: Late Quaternary climate oscillations had major impacts on species distributions and abundances across the northern Holarctic. While many large mammals in this region went extinct towards the end of the Quaternary, some species survived and flourished. Here, we examine population dynamics and range shifts of one of the most widely distributed of these, the moose (Alces alces). Location: Northern Holarctic. Taxon: Moose (A. alces). Methods: We collected samples of modern and ancient moose from across their present and former range. We assessed their phylogeographical relations using part of the mitochondrial DNA in conjunction with radiocarbon dating to investigate the history of A. alces during the last glacial. Results: This species has a relatively shallow history, with the most recent common ancestor estimated at ca. 150–50 kyr. Ancient samples corroborate that its region of greatest diversity is in east Asia, supporting proposals that this is the region of origin of all extant moose. Both eastern and western haplogroups occur in the Ural Mountains during the last glacial period, implying a broader contact zone than previously proposed. It seems that this species went extinct over much of its northern range during the last glacial maximum (LGM) and recolonized the region with climate warming beginning around 15,000 yr bp. The post-LGM expansion included a movement from northeast Siberia to North America via Beringia, although the northeast Siberian source population is not the one currently occupying that area. Main conclusions: Moose are a relatively recently evolved species but have had a dynamic history. As a large-bodied subarctic browsing species, they were seemingly confined to refugia during full-glacial periods and expanded their range northwards when the boreal forest returned after the LGM. The main modern phylogeographical division is ancient, though its boundary has not remained constant. Moose population expansion into America was roughly synchronous with human and red deer expansion. © 2020 The Authors. Journal of Biogeography published by John Wiley & Sons LtdWe warmly thank the following museums, curators and people for access to samples: the late Andrei Sher, Severtsov Institute, Moscow; Andy Currant, Natural History Museum, London; Alfred Gardner, Smithsonian, Washington DC; R. Dale Guthrie, University of Alaska, Fairbanks; John de Vos, National Museum of Natural History (Naturalis), Leiden; Eileen Westwig, American Museum of Natural History, NY; Fyodor Shidlovsky, Ice-Age Museum, Moscow; Tong Haowen, Institute of Vertebrate Palaeontology and Paleoanthropology, Beijing; Mammoth Museum, Yakutsk; Geological Museum, Yakutsk; Paleontological Institute, Moscow; Royal Alberta Museum, Edmonton; Zoological Institute, Saint Petersburg; Museum of the Institute of Plant and Animal Ecology, Ekaterinburg. We thank our Yukon First Nation research partners for their continued support for our work on the ice age fossils of Yukon Territory. We are grateful to the placer gold mining community and the Tr'ond?k Hw?ch'in First Nation for their continued support and partnership with our research in the Klondike goldfields region; and the Vuntut Gwitchin First Nation for their collaboration with research in the Old Crow region. We would also like to thank Shai Meiri for help in drawing the map and useful discussion, Tony Stuart for access to radiocarbon dates, and Iris van Pijlen for laboratory assistance. This research was funded by NERC grant NE/G00269X/1 through the European Union FP7 ERA-NET program BiodivERsA. Funding for AMS dating was provided through NERC/AHRC/ORAU Grant NF/2008/2/15

    Early mobilisation in critically ill COVID-19 patients: a subanalysis of the ESICM-initiated UNITE-COVID observational study

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    Background Early mobilisation (EM) is an intervention that may improve the outcome of critically ill patients. There is limited data on EM in COVID-19 patients and its use during the first pandemic wave. Methods This is a pre-planned subanalysis of the ESICM UNITE-COVID, an international multicenter observational study involving critically ill COVID-19 patients in the ICU between February 15th and May 15th, 2020. We analysed variables associated with the initiation of EM (within 72 h of ICU admission) and explored the impact of EM on mortality, ICU and hospital length of stay, as well as discharge location. Statistical analyses were done using (generalised) linear mixed-effect models and ANOVAs. Results Mobilisation data from 4190 patients from 280 ICUs in 45 countries were analysed. 1114 (26.6%) of these patients received mobilisation within 72 h after ICU admission; 3076 (73.4%) did not. In our analysis of factors associated with EM, mechanical ventilation at admission (OR 0.29; 95% CI 0.25, 0.35; p = 0.001), higher age (OR 0.99; 95% CI 0.98, 1.00; p ≤ 0.001), pre-existing asthma (OR 0.84; 95% CI 0.73, 0.98; p = 0.028), and pre-existing kidney disease (OR 0.84; 95% CI 0.71, 0.99; p = 0.036) were negatively associated with the initiation of EM. EM was associated with a higher chance of being discharged home (OR 1.31; 95% CI 1.08, 1.58; p = 0.007) but was not associated with length of stay in ICU (adj. difference 0.91 days; 95% CI − 0.47, 1.37, p = 0.34) and hospital (adj. difference 1.4 days; 95% CI − 0.62, 2.35, p = 0.24) or mortality (OR 0.88; 95% CI 0.7, 1.09, p = 0.24) when adjusted for covariates. Conclusions Our findings demonstrate that a quarter of COVID-19 patients received EM. There was no association found between EM in COVID-19 patients' ICU and hospital length of stay or mortality. However, EM in COVID-19 patients was associated with increased odds of being discharged home rather than to a care facility. Trial registration ClinicalTrials.gov: NCT04836065 (retrospectively registered April 8th 2021)

    Recovery of methanotrophs from disturbance: population dynamics, evenness and functioning

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    Biodiversity is claimed to be essential for ecosystem functioning, but is threatened by anthropogenic disturbances. Prokaryotes have been assumed to be functionally redundant and virtually inextinguishable. However, recent work indicates that microbes may well be sensitive to environmental disturbance. Focusing on methane-oxidizing bacteria as model organisms, we simulated disturbance-induced mortality by mixing native with sterilized paddy soil in two ratios, 1:4 and 1:40, representing moderate and severe die-offs. Disturbed microcosms were compared with an untreated control. Recovery of activity and populations was followed over 4 months by methane uptake measurements, pmoA-qPCR, pmoA-based terminal restriction fragment length polymorphism and a pmoA-based diagnostic microarray. Diversity and evenness of methanotrophs decreased in disturbed microcosms, but functioning was not compromised. We consistently observed distinctive temporal shifts between type I and type II methanotrophs, and a rapid population growth leading to even higher cell numbers comparing disturbed microcosms with the control. Overcompensating mortality suggested that population size in the control was limited by competition with other bacteria. Overall, methanotrophs showed a remarkable ability to compensate for die-offs

    Response and resilience of methanotrophs to disturbances

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    Methanotrophic bacteria are the only known biological sink for the greenhouse gas methane. Therefore, methanotrophs play a key function in carbon cycling, an important biogeochemical process that affects global climate change. Yet, little is known of their vulnerability and resilience to disturbances. Driven by the gap of knowledge, this PhD thesis is a seminal study focusing on the recovery of methanotrophs from disturbances with respect to population dynamics, diversity and functioning. Two model disturbances were tested; disturbance-induced mortality and heat shock. While the former model disturbance represents a non-selective form of disturbance, the heat shock treatment may select for sub-populations of thermo-tolerant methanotrophs. Overall, methanotrophs are shown to be remarkably resilient to induced disturbances, compensating and even over-compensating for methane uptake during recovery. Type II methanotrophs, known to be present in high abundance as resting cells, appear to become more important during disturbances. Furthermore, the establishment and subsequent development of the methanotrophic community and activity were studied along a rice paddy chronosequence. With the influx of anthropogenic influences once a rice paddy is formed, the methanotrophic community structure is anticipated to undergo a dramatic change which in turn, may affect the activity. It appears that the young and ancient rice paddies do not show clear divergence, suggesting that the methane oxidizing community was soon established after a rice paddy is formed. However, the selection of the best adapted sub-population needs time. Accordingly, long term rice agriculture allows for higher methane uptake, and may select for a methanotroph sub-population that remains active. The predominant methanotrophs found in the Chinese rice paddies are type II, mainly Methylocystis species, and type Ib (RPC-1). However, type Ib seems to be the active dominant sub-population. This and previous studies suggest specific adaptation of type Ib to rice paddy environments. Interestingly, novel sequences phylogenetically grouped between pmoA and amoA were detected. Overall, paddy soil methanotrophs are not only able to recover from disturbances, but are apparently showing specific adaptation to rice paddy environments, demonstrating their resilience in face of perturbation

    Deciphering the molecular events necessary for synergistic tumor cell apoptosis mediated by the histone deacetylase inhibitor vorinostat and the BH3 mimetic ABT-737

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    The concept of personalized anticancer therapy is based on the use of targeted therapeutics through in-depth knowledge of the molecular mechanisms of action of these agents when used alone and in combination. We have identified the apoptotic proteins and pathways necessary for synergistic tumor cell apoptosis and in vivo antitumor responses seen when the HDAC inhibitor vorinostat is combined with the BH3-mimetic ABT-737 in lymphomas overexpressing Bcl-2. Vorinostat "primes" tumors overexpressing Bcl-2 for rapid ABT-737-mediated apoptosis by inducing expression of the BH3-only gene bmf. Moreover, these synergistic effects of vorinostat/ABT-737 were blunted in cells with an inactive p53 pathway or in cells lacking expression of the p53 target gene, noxa. These studies show the important and complex functional interaction between specific proapoptotic BH3-only proteins and the BH3-mimetic compound ABT-737 and provide the most comprehensive functional link between tumor genotype and the apoptotic and therapeutic effects of HDACi combined with ABT-73

    On the fauna of hoppers, true bugs and psyllids of Palatine, Germany (Hemiptera: Auchenorrhyncha, Heteroptera und Psylloidea)

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    Die 27. mitteleuropäische Zikadentagung fand vom 16.-18. Juli 2021 in Landau, Rheinland-Pfalz, Deutschland, statt. Beprobt wurden mehrere für die Region typische Lebensräume: ein Binnendünengebiet, eine neu geschaffene Waldweide mit Quellmoor im Pfälzerwald, extensiv genutzte Streuobstbereiche mit Schafbeweidung sowie Rinderweiden entlang des Flusses Queich westlich von Landau. Insgesamt wurden 188 Zikaden-, 35 Wanzen- und 14 Blattfloharten gesammelt. Zu den seltenen und ungewöhnlichen Arten gehörten Sardius argus auf einer extensiv genutzten Streuobstwiese und Scottianella dalei im Quellmoor. Viele der nachgewiesenen Arten sind Bewohner artenreicher Grünlandbereiche und durch die Intensivierung der Landwirtschaft bedroht. Sie sind auf eine extensive Bewirtschaftung ihres Lebensraums durch Beweidung oder Mahd und einen geringen Nährstoffgehalt angewiesen.The 27th Central European Auchenorrhyncha meeting took place in Landau, Rhineland-Palatinate, Germany, on 16-18 July 2021. Several typical habitats for the region were sampled: an inland dune area, a newly-created wood pasture with a spring mire in the Palatinate Forest, two extensively used orchard areas, as well as riparian pastures along the river Queich. In total, 188 Auchenorrhyncha species, comprising 29 % of the German fauna, were collected. In addition, 35 Heteroptera species and 14 Psylloidea species were found. Rare and unusual hopper species for Germany include Sardius argus in an extensively used traditional orchard area and Scottianella dalei in a spring mire. Many of the species that were collected depend on species-rich grasslands, an extensive management and low nutrient levels. They are thus threatened by agricultural intensification and the abandonment of traditional management practices and subsequent shrub encroachment

    Emergence of Anomalous Dynamics in soft matter probed at the European XFEL

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    Dynamics and kinetics in soft matter physics, biology, and nanoscience frequently occur on fast (sub)microsecond but not ultrafast timescales which are difficult to probe experimentally. The European X-ray Free-Electron Laser (European XFEL), a megahertz hard X-ray Free-Electron Laser source, enables such experiments via taking series of diffraction patterns at repetition rates of up to 4.5 MHz. Here, we demonstrate X-ray photon correlation spectroscopy (XPCS) with submicrosecond time resolution of soft matter samples at the European XFEL. We show that the XFEL driven by a superconducting accelerator provides unprecedented beam stability within a pulse train. We performed microsecond sequential XPCS experiments probing equilibrium and nonequilibrium diffusion dynamics in water. We find nonlinear heating on microsecond timescales with dynamics beyond hot Brownian motion and superheated water states persisting up to 100 μs at high fluences. At short times up to 20 μs we observe that the dynamics do not obey the Stokes–Einstein predictions
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