TY - JOUR A1 - Knox-Brown, Patrick A1 - Rindfleisch, Tobias A1 - Günther, Anne A1 - Balow, Kim A1 - Bremer, Anne A1 - Walther, Dirk A1 - Miettinen, Markus S. A1 - Hincha, Dirk K. A1 - Thalhammer, Anja T1 - Similar Yet Different BT - Structural and Functional Diversity among Arabidopsis thaliana LEA_4 Proteins JF - International Journal of Molecular Sciences N2 - The importance of intrinsically disordered late embryogenesis abundant (LEA) proteins in the tolerance to abiotic stresses involving cellular dehydration is undisputed. While structural transitions of LEA proteins in response to changes in water availability are commonly observed and several molecular functions have been suggested, a systematic, comprehensive and comparative study of possible underlying sequence-structure-function relationships is still lacking. We performed molecular dynamics (MD) simulations as well as spectroscopic and light scattering experiments to characterize six members of two distinct, lowly homologous clades of LEA_4 family proteins from Arabidopsis thaliana. We compared structural and functional characteristics to elucidate to what degree structure and function are encoded in LEA protein sequences and complemented these findings with physicochemical properties identified in a systematic bioinformatics study of the entire Arabidopsis thaliana LEA_4 family. Our results demonstrate that although the six experimentally characterized LEA_4 proteins have similar structural and functional characteristics, differences concerning their folding propensity and membrane stabilization capacity during a freeze/thaw cycle are obvious. These differences cannot be easily attributed to sequence conservation, simple physicochemical characteristics or the abundance of sequence motifs. Moreover, the folding propensity does not appear to be correlated with membrane stabilization capacity. Therefore, the refinement of LEA_4 structural and functional properties is likely encoded in specific patterns of their physicochemical characteristics. KW - IDP KW - LEA protein KW - abiotic stress KW - dehydration KW - conformational rearrangement KW - membrane stabilization KW - sequence-structure-function relationship Y1 - 2020 U6 - https://doi.org/10.3390/ijms21082794 SN - 1422-0067 VL - 21 IS - 8 PB - Molecular Diversity Preservation International CY - Basel ER - TY - JOUR A1 - Singh, Jasbir A1 - Dani, Harinder M. A1 - Sharma, Reeta A1 - Steinberg, Pablo T1 - Inhibition of the biosynthesis of SRP polypeptides and secretory proteins by aflatoxin B-1 can disrupt protein targeting JF - Cell biochemistry and function N2 - Cell culture and western blotting studies revealed that aflatoxin B-1 (AFB(1)) inhibits the biosynthesis of two of the constituent polypeptides of signal recognition particle (SRP) (SRP54 and 72). SRP escorts polyribosomes carrying signal peptides from free form in the cytosol to the bound form on endoplasmic reticulum (ER) membrane during protein targeting. These effects of AFB(1) on SRP biosynthesis may inhibit the formation of functional SRP Our experiments have further shown that AFB(1) also inhibits the biosynthesis/translocation of a secretory protein, preprolactin, which fails to appear in the lumen of ER consequent to the treatment with this hepatocarcinogen. The results of the experiments presented in this article therefore enable us to infer for the first time that aflatoxin B-1 may inhibit the functioning of SRP as an escort and deplete the ER of polyribosomes for secretory protein synthesis. As these secretory proteins are important components of the plasma membrane, gap junctions and intercellular matrix, their absence from these locations could disturb cell to cell communication leading to tumorigenesis. KW - aflatoxin B-1 KW - SRP KW - protein targeting KW - protein translocation KW - western blotting Y1 - 2005 U6 - https://doi.org/10.1027/cbf.1285 SN - 0263-6484 VL - 24 SP - 507 EP - 510 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Oberauer, Klaus T1 - Reasoning with conditionals: A test of formal models of four theories JF - Cognitive psychology N2 - The four dominant theories of reasoning from conditionals are translated into formal models: The theory of mental models (Johnson-Laird, P. N., & Byrne, R. M. J. (2002). Conditionals: a theory of meaning, pragmatics, and inference. Psychological Review, 109, 646-678), the suppositional theory (Evans, J. S. B. T., & Over, D. E. (2004). If. Oxford: Oxford University Press), a dual-process variant of the model theory (Verschueren, N., Schaeken, W., & d'Ydewalle, G. (2005). A dual-process specification of causal conditional reasoning. Thinking & Reasoning, 11, 278-293), and the probabilistic theory (Oaksford, M., Chater, N., & Larkin, J. (2000). Probabilities and polarity biases in conditional inference. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26, 883-899). The first three theories are formalized as multinomial models. The models are applied to the frequencies of patterns of acceptance or rejection across the four basic inferences modus ponens, acceptance of the consequent, denial of the antecedent, and modus tollens. Model fits are assessed for two large data sets, one representing reasoning with abstract, basic conditionals, the other reflecting reasoning with pseudo-realistic causal and non-causal conditionals. The best account of the data was provided by a modified version of the mental-model theory, augmented by directionality, and by the dual-process model. KW - conditionals KW - reasoning KW - multinomial models Y1 - 2006 U6 - https://doi.org/10.1016/j.cogpsych.2006.04.001 SN - 0010-0285 VL - 53 IS - 3 SP - 238 EP - 283 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Mohsen, Ayman A1 - Kind, Rainer A1 - Sobolev, Stephan Vladimir A1 - Weber, Michael T1 - Thickness of the lithosphere east of the Dead Sea Transform JF - Geophysical journal international N2 - We use the S receiver function method to study the lithosphere at the Dead Sea Transform (DST). A temporary network of 22 seismic broad-band stations was operated on both sides of the DST from 2000 to 2001 as part of the DESERT project. We also used data from six additional permanent broad-band seismic stations at the DST and in the surrounding area, that is, in Turkey, Saudi Arabia, Egypt and Cyprus. Clear S-to-P converted phases from the crust-mantle boundary (Moho) and a deeper discontinuity, which we interpret as lithosphere-asthenosphere boundary (LAB) have been observed. The Moho depth (30-38 km) obtained from S receiver functions agrees well with the results from P receiver functions and other geophysical data. We observe thinning of the lithosphere on the eastern side of the DST from 80 km in the north of the Dead Sea to about 65 km at the Gulf of Aqaba. On the western side of the DST, the few data indicate a thin LAB of about 65 km. For comparison, we found a 90-km-thick lithosphere in eastern Turkey and a 160-km-thick lithosphere under the Arabian shield, respectively. These observations support previous suggestions, based on xenolith data, heat flow observations, regional uplift history and geodynamic modelling, that the lithosphere around DST has been significantly thinned in the Late Cenozoic, likely following rifting and spreading of the Red Sea. KW - Dead Sea Transform KW - S receiver functions KW - thickness of the lithosphere Y1 - 2006 U6 - https://doi.org/10.1111/j.1365-246X.2006.03185.x SN - 0956-540X SN - 1365-246X VL - 167 IS - 2 SP - 845 EP - 852 PB - Blackwell CY - Oxford ER - TY - JOUR A1 - Garcia, A. L. A1 - Steiniger, J. A1 - Reich, S. C. A1 - Weickert, M. O. A1 - Harsch, I. A1 - Machowetz, A. A1 - Mohlig, M. A1 - Spranger, Joachim A1 - Rudovich, N. N. A1 - Meuser, F. A1 - Doerfer, J. A1 - Katz, N. A1 - Speth, M. A1 - Zunft, Hans-Joachim Franz A1 - Pfeiffer, Andreas F. H. A1 - Koebnick, Corinna T1 - Arabinoxylan fibre consumption improved glucose metabolism, but did not affect serum adipokines in subjects with impaired glucose tolerance JF - Hormone and metabolic research N2 - The consumption of arabinoxylan, a soluble fibre fraction, has been shown to improve glycemic control in type 2 diabetic subjects. Soluble dietary fibre may modulate gastrointestinal or adipose tissue hormones regulating food intake. The present study investigated the effects of arabinoxylan consumption on serum glucose, insulin, lipids, leptin, adiponectin and resistin in subjects with impaired glucose tolerance. In a randomized, single-blind, controlled, crossover intervention trial, 11 adults consumed white bread rolls as either placebo or supplemented with 15g arabinoxylan for 6 weeks with a 6-week washout period. Fasting serum glucose, insulin, triglycerides, unesterified fatty acids, apolipoprotein A1 and B, adiponectin, resistin and leptin were assessed before and after intervention. Fasting serum glucose, serum triglycerides and apolipoprotein A-1 were significantly lower during arabinoxylan consumption compared to placebo (p = 0.029, p = 0.047; p = 0.029, respectively). No effects of arabinoxylan were observed for insulin, adiponectin, leptin and resistin as well as for apolipoprotein B, and unesterified fatty acids. In conclusion, the consumption of AX in subjects with impaired glucose tolerance improved fasting serum glucose, and triglycerides. However, this beneficial effect was not accompanied by changes in fasting adipokine concentrations. KW - dietary fibre KW - arabinoxylan KW - adiponectin KW - resistin KW - leptin Y1 - 2006 U6 - https://doi.org/10.1055/s-2006-955089 SN - 0018-5043 VL - 38 IS - 2 SP - 761 EP - 766 PB - Thieme CY - Stuttgart ER - TY - JOUR A1 - Maares, Maria A1 - Keil, Claudia A1 - Koza, Jenny A1 - Straubing, Sophia A1 - Schwerdtle, Tanja A1 - Haase, Hajo T1 - In Vitro Studies on Zinc Binding and Buffering by Intestinal Mucins JF - International Journal of Molecular Sciences N2 - The investigation of luminal factors influencing zinc availability and accessibility in the intestine is of great interest when analyzing parameters regulating intestinal zinc resorption. Of note, intestinal mucins were suggested to play a beneficial role in the luminal availability of zinc. Their exact zinc binding properties, however, remain unknown and the impact of these glycoproteins on human intestinal zinc resorption has not been investigated in detail. Thus, the aim of this study is to elucidate the impact of intestinal mucins on luminal uptake of zinc into enterocytes and its transfer into the blood. In the present study, in vitro zinc binding properties of mucins were analyzed using commercially available porcine mucins and secreted mucins of the goblet cell line HT-29-MTX. The molecular zinc binding capacity and average zinc binding affinity of these glycoproteins demonstrates that mucins contain multiple zinc-binding sites with biologically relevant affinity within one mucin molecule. Zinc uptake into the enterocyte cell line Caco-2 was impaired by zinc-depleted mucins. Yet this does not represent their form in the intestinal lumen in vivo under zinc adequate conditions. In fact, zinc-uptake studies into enterocytes in the presence of mucins with differing degree of zinc saturation revealed zinc buffering by these glycoproteins, indicating that mucin-bound zinc is still available for the cells. Finally, the impact of mucins on zinc resorption using three-dimensional cultures was studied comparing the zinc transfer of a Caco-2/HT-29-MTX co-culture and conventional Caco-2 monoculture. Here, the mucin secreting co-cultures yielded higher fractional zinc resorption and elevated zinc transport rates, suggesting that intestinal mucins facilitate the zinc uptake into enterocytes and act as a zinc delivery system for the intestinal epithelium. KW - intestinal zinc resorption KW - zinc binding KW - mucus layer KW - intestinal mucins KW - in vitro intestinal model KW - goblet cells KW - Caco-2/HT-29-MTX-model Y1 - 2018 U6 - https://doi.org/10.3390/ijms19092662 SN - 1422-0067 VL - 19 IS - 9 ER - TY - JOUR A1 - Damaschun, Ferdinand T1 - Christian Gottfried Ehrenberg und die Entwicklung der Mikroskop-Technik im 19. Jahrhundert BT - Lebensbilder eines Naturforschers JF - HiN : Alexander von Humboldt im Netz = Christian Gottfried Ehrenberg N2 - Ab Mitte der 1820er Jahre erfuhr die Mikroskop- Technik eine stürmische Entwicklung. Dadurch, dass es gelang, nach und nach die optischen Fehler zu korrigieren, verbesserte sich die Auflösung bis zum Ende des Jahrhunderts um den Faktor 10 von 3 μm auf 0,3 μm. Um 1820 begann Christian Gottfried Ehrenberg mit mikroskopischen Untersuchungen. Er nutzte zunächst ein einfaches Nürnberger Mikroskop. 1832 erwarb er ein Mikroskop aus der Berliner Werkstatt von Pistor & Schiek, das er dann zeitlebens nutzte. Ein Vergleich der Leistungsfähigkeit seines Instruments mit der für seine Untersuchungen notwendigen Auflösung zeigt, dass es für seine Untersuchungen vollkommen genügte. Für seine Untersuchungsobjekte entwickelte er Präparationstechniken und Aufbewahrungsmethoden für die Dauerpräparate. Da er auch die mikroskopischen Abbildungen bis hin zu den Vorlagen für die Kupfertafeln selbst anfertigte, behielt er den gesamten Prozess von der Präparation bis zum Druck der Ergebnisse stets in der Hand. N2 - From the mid-1820s onwards, microscope technology underwent a rapid development. Thanks to new possibilities for correcting optical errors, microscope resolution improved by a factor of 10 from 3 μm to 0.3 μm by the end of the century. Ehrenberg began his investigations in 1820 with a simple “Nürnberger Mikroskop”. In 1832, he acquired a microscope from the Berlin workshop of Pistor & Schiek, which he then used throughout his life. By comparing the performance of his instrument with the resolution required for his objects, this article demonstrates that the Pistor & Schiek was perfectly adequate for his investigations. Furthermore, it traces Ehrenberg’s process of producing microscopic images, which he controlled from start to finish: from the preparation and storage of specimens according to special methods he developed himself to the execution of the illustrations that would be used as templates for the copper plates. N2 - À partir du milieu des années 1820, la technologie des microscopes a connu un développement rapide. Grâce aux nouvelles possibilités de correction des erreurs optiques, il a été possible de corriger et d’améliorer la résolution des microscopes par un facteur de 10, passant de 3 μm à 0,3 μm à la fin du siècle. Ehrenberg a commencé ses recherches en 1820 avec un simple « Nürnberger Mikroskop ». En 1832, il a acquis un microscope de l’atelier berlinois de Pistor & Schiek, qu’il a ensuite utilisé toute sa vie. En comparant les performances de son instrument avec la résolution requise pour ses objets, cet article montre que le Pistor & Schiek était parfaitement adapté à ses investigations. En outre, il retrace le processus de production d’images microscopiques d’Ehrenberg, qu’il a contrôlé de bout en bout: de la préparation et du stockage des spécimens selon des méthodes spéciales qu’il a lui-même développées jusqu’à l’exécution des illustrations qui allaient servir de modèles pour les plaques de cuivre. KW - Ehrenberg KW - Mikroskop KW - Glas KW - Infusorien KW - Infusionsthierchen KW - Mikrogeologie KW - Chevalier KW - Pistor & Schiek Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515218 SN - 1617-5239 SN - 2568-3543 VL - XXII IS - 42 SP - 119 EP - 134 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Böhme, Katrin T1 - Das große Ganze. Christian Gottfried Ehrenberg und die Gesellschaft Naturforschender Freunde zu Berlin BT - Lebensbilder eines Naturforschers JF - HiN : Alexander von Humboldt im Netz = Christian Gottfried Ehrenberg N2 - Als langjähriges und aktives Mitglied der Gesellschaft Naturforschender Freunde zu Berlin bestimmte Ehrenberg ihre Aktivitäten und ihr Ansehen maßgeblich mit. Seine Beiträge zu den Sitzungen und Schriften und seine Rolle als Bewohner des gesellschaftseigenen Hauses förderten in der GNF sowohl Fortschritt als auch Beständigkeit. Das Ziel der Naturgeschichte des 18. Jahrhunderts, also die Entdeckung, Beschreibung und Bewahrung möglichst aller Organismen- und Gesteinsarten, wurde in der GNF bis in die zweite Hälfte des 19. Jahrhunderts tradiert. Ehrenbergs wissenschaftliche Leistungen, insbesondere seine zahlreichen Entdeckungen mit Hilfe des Mikroskops, stehen ganz in dieser Tradition. N2 - As a long-time and active member of the Gesellschaft naturforschender Freunde zu Berlin (Berlin Society of Friends of Natural Research), Ehrenberg played a major role in determining the society’s activities and shaping its reputation. His contributions to the meetings, his writings, and his role as a resident of the house belonging to the society promoted both progress and permanence of the association. The goal of natural history in the 18th century, that is, the discovery, description, and preservation of as many species of organisms and rocks as possible, was carried forth by the Gesellschaft naturforschender Freunde into the second half of the 19th century. Ehrenberg’s scientific achievements, particularly his numerous discoveries with the aid of the microscope, belong entirely to this tradition. N2 - En tant que membre actif et de longue date de la Gesellschaft naturforschender Freunde zu Berlin (Société des amis naturalistes de Berlin), Ehrenberg a joué un rôle majeur en déterminant les activités et la réputation de cette société. Ses contributions aux réunions et aux écrits et son statut d’habitant de la maison appartenant à la société ont favorisé à la fois le progrès et la pérennité de l’association. L’objectif de l’histoire naturelle au XVIIIe siècle, c’est-à-dire la découverte, la description et la préservation d’autant d’espèces d’organismes et de roches que possible, a été perpétué par la Gesellschaft naturforschender Freunde jusqu’à la seconde moitié du XIXe siècle. Les travaux scientifiques d’Ehrenberg, notamment ses nombreuses découvertes à l’aide du microscope, s’inscrivent entièrement dans cette tradition. KW - Gesellschaft Naturforschender Freunde zu Berlin KW - Ehrenberg KW - GNF KW - Infusorienwerke Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-515226 SN - 1617-5239 SN - 2568-3543 VL - XXII IS - 42 SP - 155 EP - 169 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - JOUR A1 - Nitze, Ingmar A1 - Grosse, Guido A1 - Jones, Benjamin M. A1 - Romanovsky, Vladimir E. A1 - Boike, Julia T1 - Remote sensing quantifies widespread abundance of permafrost region disturbances across the Arctic and Subarctic JF - Nature Communications N2 - Local observations indicate that climate change and shifting disturbance regimes are causing permafrost degradation. However, the occurrence and distribution of permafrost region disturbances (PRDs) remain poorly resolved across the Arctic and Subarctic. Here we quantify the abundance and distribution of three primary PRDs using time-series analysis of 30-m resolution Landsat imagery from 1999 to 2014. Our dataset spans four continental-scale transects in North America and Eurasia, covering similar to 10% of the permafrost region. Lake area loss (-1.45%) dominated the study domain with enhanced losses occurring at the boundary between discontinuous and continuous permafrost regions. Fires were the most extensive PRD across boreal regions (6.59%), but in tundra regions (0.63%) limited to Alaska. Retrogressive thaw slumps were abundant but highly localized (< 10(-5)%). Our analysis synergizes the global-scale importance of PRDs. The findings highlight the need to include PRDs in next-generation land surface models to project the permafrost carbon feedback. Y1 - 2018 U6 - https://doi.org/10.1038/s41467-018-07663-3 SN - 2041-1723 VL - 9 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Kath, Nadja J. A1 - Boit, Alice A1 - Guill, Christian A1 - Gaedke, Ursula T1 - Accounting for activity respiration results in realistic trophic transfer efficiencies in allometric trophic network (ATN) models JF - Theoretical ecology N2 - Allometric trophic network (ATN) models offer high flexibility and scalability while minimizing the number of parameters and have been successfully applied to investigate complex food web dynamics and their influence on food web diversity and stability. However, the realism of ATN model energetics has never been assessed in detail, despite their critical influence on dynamic biomass and production patterns. Here, we compare the energetics of the currently established original ATN model, considering only biomass-dependent basal respiration, to an extended ATN model version, considering both basal and assimilation-dependent activity respiration. The latter is crucial in particular for unicellular and invertebrate organisms which dominate the metabolism of pelagic and soil food webs. Based on metabolic scaling laws, we show that the extended ATN version reflects the energy transfer through a chain of four trophic levels of unicellular and invertebrate organisms more realistically than the original ATN version. Depending on the strength of top-down control, the original ATN model yields trophic transfer efficiencies up to 71% at either the third or the fourth trophic level, which considerably exceeds any realistic values. In contrast, the extended ATN version yields realistic trophic transfer efficiencies 30% at all trophic levels, in accordance with both physiological considerations and empirical evidence from pelagic systems. Our results imply that accounting for activity respiration is essential for consistently implementing the metabolic theory of ecology in ATN models and for improving their quantitative predictions, which makes them more powerful tools for investigating the dynamics of complex natural communities. KW - Food web KW - Trophic transfer efficiency KW - Allometric trophic network model KW - Allometry KW - Energy transfer KW - Activity respiration Y1 - 2018 U6 - https://doi.org/10.1007/s12080-018-0378-z SN - 1874-1738 SN - 1874-1746 VL - 11 IS - 4 SP - 453 EP - 463 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Fritz, Michael Andre A1 - Rosa, Stefanie A1 - Sicard, Adrien T1 - Mechanisms Underlying the Environmentally Induced Plasticity of Leaf Morphology JF - Frontiers in genetics N2 - The primary function of leaves is to provide an interface between plants and their environment for gas exchange, light exposure and thermoregulation. Leaves have, therefore a central contribution to plant fitness by allowing an efficient absorption of sunlight energy through photosynthesis to ensure an optimal growth. Their final geometry will result from a balance between the need to maximize energy uptake while minimizing the damage caused by environmental stresses. This intimate relationship between leaf and its surroundings has led to an enormous diversification in leaf forms. Leaf shape varies between species, populations, individuals or even within identical genotypes when those are subjected to different environmental conditions. For instance, the extent of leaf margin dissection has, for long, been found to inversely correlate with the mean annual temperature, such that Paleobotanists have used models based on leaf shape to predict the paleoclimate from fossil flora. Leaf growth is not only dependent on temperature but is also regulated by many other environmental factors such as light quality and intensity or ambient humidity. This raises the question of how the different signals can be integrated at the molecular level and converted into clear developmental decisions. Several recent studies have started to shed the light on the molecular mechanisms that connect the environmental sensing with organ-growth and patterning. In this review, we discuss the current knowledge on the influence of different environmental signals on leaf size and shape, their integration as well as their importance for plant adaptation. KW - plants KW - leaf morphology KW - environment KW - developmental plasticity KW - gene regulatory networks KW - sensory system KW - gene responsiveness Y1 - 2018 U6 - https://doi.org/10.3389/fgene.2018.00478 SN - 1664-8021 VL - 9 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Walther, Sophia A1 - Guanter, Luis A1 - Heim, Birgit A1 - Jung, Martin A1 - Duveiller, Gregory A1 - Wolanin, Aleksandra A1 - Sachs, Torsten T1 - Assessing the dynamics of vegetation productivity in circumpolar regions with different satellite indicators of greenness and photosynthesis JF - Biogeosciences N2 - High-latitude treeless ecosystems represent spatially highly heterogeneous landscapes with small net carbon fluxes and a short growing season. Reliable observations and process understanding are critical for projections of the carbon balance of the climate-sensitive tundra. Space-borne remote sensing is the only tool to obtain spatially continuous and temporally resolved information on vegetation greenness and activity in remote circumpolar areas. However, confounding effects from persistent clouds, low sun elevation angles, numerous lakes, widespread surface inundation, and the sparseness of the vegetation render it highly challenging. Here, we conduct an extensive analysis of the timing of peak vegetation productivity as shown by satellite observations of complementary indicators of plant greenness and photosynthesis. We choose to focus on productivity during the peak of the growing season, as it importantly affects the total annual carbon uptake. The suite of indicators are as follows: (1) MODIS-based vegetation indices (VIs) as proxies for the fraction of incident photosynthetically active radiation (PAR) that is absorbed (fPAR), (2) VIs combined with estimates of PAR as a proxy of the total absorbed radiation (APAR), (3) sun-induced chlorophyll fluorescence (SIF) serving as a proxy for photosynthesis, (4) vegetation optical depth (VOD), indicative of total water content and (5) empirically upscaled modelled gross primary productivity (GPP). Averaged over the pan-Arctic we find a clear order of the annual peak as APAR <= GPP < SIF < VIs/VOD. SIF as an indicator of photosynthesis is maximised around the time of highest annual temperatures. The modelled GPP peaks at a similar time to APAR. The time lag of the annual peak between APAR and instantaneous SIF fluxes indicates that the SIF data do contain information on light-use efficiency of tundra vegetation, but further detailed studies are necessary to verify this. Delayed peak greenness compared to peak photosynthesis is consistently found across years and land-cover classes. A particularly late peak of the normalised difference vegetation index (NDVI) in regions with very small seasonality in greenness and a high amount of lakes probably originates from artefacts. Given the very short growing season in circumpolar areas, the average time difference in maximum annual photosynthetic activity and greenness or growth of 3 to 25 days (depending on the data sets chosen) is important and needs to be considered when using satellite observations as drivers in vegetation models. Y1 - 2018 U6 - https://doi.org/10.5194/bg-15-6221-2018 SN - 1726-4170 SN - 1726-4189 VL - 15 IS - 20 SP - 6221 EP - 6256 PB - Copernicus CY - Göttingen ER - TY - JOUR A1 - Kaboth-Bahr, Stefanie A1 - Bahr, André A1 - Zeeden, Christian A1 - Yamoah, Kweku A. A1 - Lone, Mahjoor Ahmad A1 - Chuang, Chih-Kai A1 - Löwemark, Ludvig A1 - Wei, Kuo-Yen T1 - A tale of shifting relations BT - East Asian summer and winter monsoon variability during the Holocene JF - Scientific Reports N2 - Understanding the dynamics between the East Asian summer (EASM) and winter monsoon (EAWM) is needed to predict their variability under future global warming scenarios. Here, we investigate the relationship between EASM and EAWM as well as the mechanisms driving their variability during the last 10,000 years by stacking marine and terrestrial (non-speleothem) proxy records from the East Asian realm. This provides a regional and proxy independent signal for both monsoonal systems. The respective signal was subsequently analysed using a linear regression model. We find that the phase relationship between EASM and EAWM is not time-constant and significantly depends on orbital configuration changes. In addition, changes in the Atlantic Meridional Overturning circulation, Arctic sea-ice coverage, El Niño-Southern Oscillation and Sun Spot numbers contributed to millennial scale changes in the EASM and EAWM during the Holocene. We also argue that the bulk signal of monsoonal activity captured by the stacked non-speleothem proxy records supports the previously argued bias of speleothem climatic archives to moisture source changes and/or seasonality. KW - Environmental sciences KW - Ocean sciences KW - Solid Earth sciences Y1 - 2020 U6 - https://doi.org/10.1038/s41598-021-85444-7 SN - 2045-2322 VL - 11 PB - Macmillan Publishers Limited, part of Springer Nature CY - London ER - TY - JOUR A1 - Schaal, Frederik A1 - Rutloh, Michael A1 - Weidenfeld, Susanne A1 - Stumpe, Joachim A1 - Michler, Peter A1 - Pruss, Christof A1 - Osten, Wolfgang T1 - Optically addressed modulator for tunable spatial polarization control JF - Optics express : the international electronic journal of optics N2 - We present an optically addressed non-pixelated spatial light modulator. The system is based on reversible photoalignment of a LC cell using a red light sensitive novel azobenzene photoalignment layer. It is an electrode-free device that manipulates the liquid crystal orientation and consequently the polarization via light without artifacts caused by electrodes. The capability to miniaturize the spatial light modulator allows the integration into a microscope objective. This includes a miniaturized 200 channel optical addressing system based on a VCSEL array and hybrid refractive-diffractive beam shapers. As an application example, the utilization as a microscope objective integrated analog phase contrast modulator is shown. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement Y1 - 2018 U6 - https://doi.org/10.1364/OE.26.028119 SN - 1094-4087 VL - 26 IS - 21 SP - 28119 EP - 28130 PB - Optical Society of America CY - Washington ER - TY - JOUR A1 - Peng, Junjie A1 - Liu, Danxu A1 - Wang, Yingtao A1 - Zeng, Ying A1 - Cheng, Feng A1 - Zhang, Wenqiang T1 - Weight-based strategy for an I/O-intensive application at a cloud data center JF - Concurrency and computation : practice & experience N2 - Applications with different characteristics in the cloud may have different resources preferences. However, traditional resource allocation and scheduling strategies rarely take into account the characteristics of applications. Considering that an I/O-intensive application is a typical type of application and that frequent I/O accesses, especially small files randomly accessing the disk, may lead to an inefficient use of resources and reduce the quality of service (QoS) of applications, a weight allocation strategy is proposed based on the available resources that a physical server can provide as well as the characteristics of the applications. Using the weight obtained, a resource allocation and scheduling strategy is presented based on the specific application characteristics in the data center. Extensive experiments show that the strategy is correct and can guarantee a high concurrency of I/O per second (IOPS) in a cloud data center with high QoS. Additionally, the strategy can efficiently improve the utilization of the disk and resources of the data center without affecting the service quality of applications. KW - IOPS KW - process scheduling KW - random I KW - O KW - small files KW - weight Y1 - 2018 U6 - https://doi.org/10.1002/cpe.4648 SN - 1532-0626 SN - 1532-0634 VL - 30 IS - 19 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Seiß, Martin A1 - Albers, Nicole A1 - Sremčević, Miodrag A1 - Schmidt, Jürgen A1 - Salo, Heikki A1 - Seiler, Michael A1 - Hoffmann, Holger A1 - Spahn, Frank T1 - Hydrodynamic Simulations of Moonlet-induced Propellers in Saturn's Rings BT - Application to Bleriot JF - The astronomical journal N2 - One of the biggest successes of the Cassini mission is the detection of small moons (moonlets) embedded in Saturns rings that cause S-shaped density structures in their close vicinity, called propellers. Here, we present isothermal hydrodynamic simulations of moonlet-induced propellers in Saturn's A ring that denote a further development of the original model. We find excellent agreement between these new hydrodynamic and corresponding N-body simulations. Furthermore, the hydrodynamic simulations confirm the predicted scaling laws and the analytical solution for the density in the propeller gaps. Finally, this mean field approach allows us to simulate the pattern of the giant propeller Blériot, which is too large to be modeled by direct N-body simulations. Our results are compared to two stellar occultation observations by the Cassini Ultraviolet Imaging Spectrometer (UVIS), which intersect the propeller Blériot. Best fits to the UVIS optical depth profiles are achieved for a Hill radius of 590 m, which implies a moonlet diameter of about 860 m. Furthermore, the model favors a kinematic shear viscosity of the surrounding ring material of ν0 = 340 cm2 s−1, a dispersion velocity in the range of 0.3 cm s−1 < c0 < 1.5 cm s−1, and a fairly high bulk viscosity 7 < ξ0/ν0 < 17. These large transport values might be overestimated by our isothermal ring model and should be reviewed by an extended model including thermal fluctuations. KW - diffusion KW - hydrodynamics KW - planets and satellites: rings Y1 - 2018 U6 - https://doi.org/10.3847/1538-3881/aaed44 SN - 0004-6256 SN - 1538-3881 VL - 157 IS - 1 PB - IOP Publishing Ltd. CY - Bristol ER - TY - JOUR A1 - Traxler, Juliane A1 - Hanssen, Marjolein M. A1 - Lautenbacher, Stefan A1 - Ottawa, Fabian A1 - Peters, Madelon L. T1 - General versus pain-specific cognitions BT - Pain catastrophizing but not optimism influences conditioned pain modulation JF - European journal of pain N2 - Background Previous studies found evidence that dispositional optimism is related to lower pain sensitivity. Recent findings suggest that temporarily increasing optimism by means of imagining a positive future may also have pain-alleviating effects. Objectives The present experiment was designed to investigate conditioned pain modulation (CPM) as a potential underlying mechanism of this pain-alleviating effect of induced optimism. Methods For this purpose, 45 healthy participants were randomized into an optimistic or neutral imagery condition. Additionally, participants completed questionnaires on dispositional optimism, pain catastrophizing and pain expectations. CPM was assessed by delivering a series of five heat pain stimuli on the nondominant hand before and during immersion of the dominant hand in water of 5 degrees C for 70 s. Results A clear CPM effect was found, that is heat pain reports were lower during simultaneous cold water stimulation. Although the optimism manipulation successfully increased optimism, it did not affect pain ratings or CPM. Post hoc analyses indicated that dispositional optimism was not associated with the magnitude of CPM, but pain catastrophizing and pain expectations did significantly correlate with the CPM effect. Conclusion Pain-specific but not general cognitions appear to influence endogenous pain modulation. Significance Conditioned pain modulation is not the underlying mechanism of the pain-alleviating effects of induced optimism. However, pain-specific cognitions including pain catastrophizing and pain expectations affect endogenous pain modulation which should be taken into account in treatment and CPM research. Y1 - 2018 U6 - https://doi.org/10.1002/ejp.1294 SN - 1090-3801 SN - 1532-2149 VL - 23 IS - 1 SP - 150 EP - 159 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Salzwedel, Annett A1 - Heidler, Maria-Dorothea A1 - Meng, Karin A1 - Schikora, Martin A1 - Wegscheider, Karl A1 - Reibis, Rona Katharina A1 - Völler, Heinz T1 - Impact of cognitive performance on disease-related knowledge six months after multi-component rehabilitation in patients after an acute cardiac event JF - European journal of preventive cardiology : the official ESC journal for primary & secondary cardiovascular prevention, rehabilitation and sports cardiology N2 - Background Although associations between cardiovascular diseases and cognitive impairment are well known, the impact of cognitive performance on the success of patient education as a core component of cardiac rehabilitation remains insufficiently investigated so far. Design Prospective observational study in two inpatient cardiac rehabilitation centres between September 2014 and August 2015 with a follow-up six months after cardiac rehabilitation. Method At admission to and discharge from cardiac rehabilitation, the cognitive performance of 401 patients (54.5 ± 6.3 years, 80% men) following an acute coronary syndrome and/or coronary artery bypass graft was tested using the Montreal Cognitive Assessment. Patients’ disease-related knowledge was determined using a quiz (22 items for medical knowledge and 12 items for healthy lifestyle and behaviour) at both times and at follow-up. The change in knowledge after cardiac rehabilitation was analysed in multivariable regression models. Potentially influencing parameters (e.g. level of education, medication, cardiovascular risk factors, coronary artery bypass graft, comorbidities, exercise capacity) were considered. Results During cardiac rehabilitation, disease-related knowledge was significantly enhanced in both scales. At follow-up, the average level of medical knowledge was significantly reduced, while lifestyle knowledge remained at a stable level. The maintenance of knowledge after cardiac rehabilitation was predominantly predicted by prior knowledge, cognitive performance at discharge from cardiac rehabilitation and, in the case of medical knowledge, by coronary artery bypass graft. Conclusion Patient education in cardiac rehabilitation led to enhanced disease-related knowledge, but the maintenance of this essentially depended on patients’ cognitive performance, especially after coronary artery bypass graft. Therefore, patient education concepts in cardiac rehabilitation should be reconsidered and adjusted as needed. KW - Mild cognitive impairment KW - cardiac rehabilitation KW - patient education KW - coronary artery disease KW - secondary prevention Y1 - 2020 U6 - https://doi.org/10.1177/2047487318791609 SN - 2047-4873 SN - 2047-4881 VL - 26 IS - 1 SP - 46 EP - 55 PB - Sage Publ. CY - London ER - TY - JOUR A1 - Maes, Sybryn L. A1 - Perring, Michael P. A1 - Vanhellemont, Margot A1 - Depauw, Leen A1 - Van den Bulcke, Jan A1 - Brumelis, Guntis A1 - Brunet, Jorg A1 - Decocq, Guillaume A1 - den Ouden, Jan A1 - Härdtle, Werner A1 - Hedl, Radim A1 - Heinken, Thilo A1 - Heinrichs, Steffi A1 - Jaroszewicz, Bogdan A1 - Kopecký, Martin A1 - Malis, Frantisek A1 - Wulf, Monika A1 - Verheyen, Kris T1 - Environmental drivers interactively affect individual tree growth across temperate European forests JF - Global change biology N2 - Forecasting the growth of tree species to future environmental changes requires abetter understanding of its determinants. Tree growth is known to respond to global‐change drivers such as climate change or atmospheric deposition, as well as to localland‐use drivers such as forest management. Yet, large geographical scale studiesexamining interactive growth responses to multiple global‐change drivers are relativelyscarce and rarely consider management effects. Here, we assessed the interactiveeffects of three global‐change drivers (temperature, precipitation and nitrogen deposi-tion) on individual tree growth of three study species (Quercus robur/petraea, Fagus syl-vatica and Fraxinus excelsior). We sampled trees along spatial environmental gradientsacross Europe and accounted for the effects of management for Quercus. We collectedincrement cores from 267 trees distributed over 151 plots in 19 forest regions andcharacterized their neighbouring environment to take into account potentially confounding factors such as tree size, competition, soil conditions and elevation. Wedemonstrate that growth responds interactively to global‐change drivers, with species ‐specific sensitivities to the combined factors. Simultaneously high levels of precipita-tion and deposition benefited Fraxinus, but negatively affected Quercus’ growth, high-lighting species‐specific interactive tree growth responses to combined drivers. ForFagus, a stronger growth response to higher temperatures was found when precipita-tion was also higher, illustrating the potential negative effects of drought stress underwarming for this species. Furthermore, we show that past forest management canmodulate the effects of changing temperatures on Quercus’ growth; individuals in plotswith a coppicing history showed stronger growth responses to higher temperatures.Overall, our findings highlight how tree growth can be interactively determined by glo-bal‐change drivers, and how these growth responses might be modulated by past for-est management. By showing future growth changes for scenarios of environmentalchange, we stress the importance of considering multiple drivers, including past man-agement and their interactions, when predicting tree growth. KW - basal area increment KW - climate change KW - Fagus KW - Fraxinus KW - historical ecology KW - nitrogen deposition KW - Quercus KW - tree-ring analysis Y1 - 2018 U6 - https://doi.org/10.1111/gcb.14493 SN - 1354-1013 SN - 1365-2486 VL - 25 IS - 1 SP - 201 EP - 217 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Meiser, Susanne A1 - Esser, Günter T1 - Interpersonal Stress Generation-A Girl Problem? BT - The Role of Depressive Symptoms, Dysfunctional Attitudes, and Gender in Early Adolescent Stress Generation JF - Journal of early adolescence N2 - To provide further insight into stress generation patterns in boys and girls around puberty, this study investigated longitudinal reciprocal relations between depressive symptoms, dysfunctional attitudes, and stress generation, the process by which individuals contribute to the occurrence of stress in interpersonal contexts (e.g., problematic social interactions) or in noninterpersonal contexts (e.g., achievement problems). A community sample of N = 924 German children and early adolescents (51.8% male) completed depressive symptoms and dysfunctional attitudes measures at T1 and again 20 months later (T2). Stressful life events were reported at T2. Dysfunctional attitudes were unrelated to stress generation. Interpersonal, but not noninterpersonal, dependent stress partially mediated the relationship between initial and later depressive symptoms, with girls being more likely to generate interpersonal stress in response to depressive symptoms. Findings underscore the role of interpersonal stress generation in the early development of depressive symptomatology, and in the gender difference in depression prevalence emerging around puberty. KW - stress generation KW - depression KW - dysfunctional attitudes KW - children and adolescents KW - gender differences Y1 - 2017 U6 - https://doi.org/10.1177/0272431617725197 SN - 0272-4316 SN - 1552-5449 VL - 39 IS - 1 SP - 41 EP - 66 PB - Sage Publ. CY - Thousand Oaks ER -